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At least 667 records · Page 37Linked to original sources
PubMed1997

Parathyroid hormone increases circulating levels of fibronectin in vivo: modulating effect of ovariectomy.

To explore the effect of PTH on circulating levels of fibronectin (FN), adult female Sprague-Dawley rats were implanted with Alzet minipumps prepared to deliver 7 pmol/h x kg BW of either human PTH (1-34) or human PTH (1-84). Both forms of the hormone led to significant and progressive increases in circulating levels of FN over the 72-h study period (P < 0.001). However, at every time point, circulating levels of FN with human PTH (hPTH) (1-84) infusion were significantly higher than with hPTH (1-34), such that at the end of the infusion, mean levels in the hPTH (1-34) group were 32.2 +/- 1.4 ng/ml, in the hPTH (1-84) group 93.8 +/- 5.4 ng/ml, and in the vehicle infused group 14.6 +/- 0.7 ng/ml. The greater agonist efficacy of hPTH (1-84) was not explained by differences in circulating levels of the hormones, and both forms of the hormone were equipotent at stimulating cAMP production by ROS 17/2.8 cells. However, hPTH (1-84) remained a more effective agonist than hPTH (1-34) at stimulating FN production in these cells (P < 0.001). Nephrectomy did not blunt the ability of PTH to increase circulating FN in vivo, indicating that the kidney was not the source of the FN produced in response to PTH. Pretreament with the potent bisphosphonate APD to block bone resorption also did not blunt the in vivo response to PTH. Parathyroidectomy did not blunt the response. Cultured fetal rat bones showed a significant 2.4-fold increase in FN production when treated with PTH. Consistent with our earlier in vitro studies (Endocrinology, 135: 1639-1644, 1994), estrogen deficiency, induced by ovariectomy, significantly diminished the ability of PTH to increase circulating FN levels in vivo (P < 0.001). We conclude that PTH increases circulating levels of FN in vivo and may be a physiologic regulator for the plasma form of this glycoprotein. The effects of PTH on circulating FN may reflect the anabolic properties of the hormone in bone and the blunted response following estrogen withdrawal could be a manifestation of the diminished bone formation vis-à-vis resorption seen in the estrogen deficient state.

Animals↗
PubMed2006

Circulating proteasomes are functional and have a subtype pattern distinct from 20S proteasomes in major blood cells.

BACKGROUND: 20S proteasomes, the proteolytic core particles of the major intracellular protein degradative pathway, are potential disease markers because they are detectable in human plasma as circulating proteasomes and their concentrations are increased in patients suffering from various diseases. To investigate the origin of circulating proteasomes, we compared some of their features with those of proteasomes isolated from major blood cells. METHODS: We isolated circulating proteasomes from the plasma of 2 patients with rheumatoid arthritis and 2 with systemic lupus erythematosus and from human plasma from healthy donors. We purified the proteasomes to apparent homogeneity and then used electron microscopy for imaging and chromatography for subtype spectrum analysis. We compared subtype results with those from 20S proteasomes purified from 4 major blood cell populations. We also tested proteasomes for enzymatic activity and immunosubunit content. RESULTS: Circulating proteasomes from plasma of healthy donors and from patients with autoimmune disease were found to have the same size and shape as erythrocyte proteasomes, be proteolytically active, and contain standard- and immunosubunits. Chromatography revealed 6 circulating proteasome subtype peaks in healthy donor plasma and 7 in patient donor plasma. Proteasomes from erythrocytes had 3 subtype peaks and those of monocytes, T-lymphocytes, and thrombocytes each had 5 different subtype peaks. CONCLUSION: Circulating proteasomes were intact and enzymatically active in plasma from healthy donors and from patients with autoimmune disease. Because the subtype patterns of circulating proteasomes clearly differ from those of proteasomes from blood cells, these cells cannot be regarded as a major source of circulating proteasomes.

Adolescent↗
PubMed2001

Circulating leptin during ovine pregnancy in relation to maternal nutrition, body composition and pregnancy outcome.

This study examined the pattern of circulating leptin in age-matched sheep during adolescent pregnancy, and its relationship with maternal dietary intake, body composition and tissue expression of the leptin gene. Overfeeding the adolescent pregnant ewe results in rapid maternal growth at the expense of the placenta, leading to growth restriction in the fetus, compared with normal fed controls. Our results demonstrate that, in the adolescent ewe, overfeeding throughout pregnancy was associated with higher maternal leptin concentrations, when compared with moderately fed controls (P<0.05), with no peak in circulating leptin towards the end of pregnancy. There was a close correlation between indices of body composition and circulating leptin levels at day 104 of gestation and at term (P<0.03). Further, when the dietary intake was switched from moderate to high, or high to moderate, at day 50 of gestation, circulating leptin levels changed rapidly, in parallel with the changes in dietary intake. Leptin mRNA levels and leptin protein in perirenal adipose tissue samples, taken at day 128 of gestation, were higher in overfed dams (P<0.04), suggesting that adipose tissue was the source of the increase in circulating leptin in the overnourished ewes. Leptin protein was also detected in placenta but leptin gene expression was negligible. However, leptin receptor gene expression was detected in the ovine placenta, suggesting that the placenta is a target organ for leptin. A negative association existed between maternal circulating leptin and fetal birth weight, placental/cotyledon weight and cotyledon number. In conclusion, in this particular ovine model, hyperleptinaemia was not observed during late pregnancy. Instead, circulating leptin concentrations reflected increased levels of leptin secretion by adipose tissue primarily as a result of the increase in body fat deposition, due to overfeeding. However, there appears to be a direct effect of overfeeding, particularly in the short term. In the nutritional switch-over study, circulating leptin concentrations changed within 48 h of the change in dietary intake. The presence of leptin protein and leptin receptor gene expression in the placenta suggests that leptin could be involved in nutrient partitioning during placental and/or fetal development.

Adipose Tissue↗
PubMed1994

Rate of antigen entry into the circulation in experimental versus naturally occurring immune complex glomerulonephritis.

This study tested the hypothesis that the rate of antigen entry into the circulation in systemic lupus erythematosus (SLE), a naturally occurring immune complex glomerulonephritis (IC-GN), is slow compared with that of traditional experimental models of IC-GN, in which the antigen is delivered rapidly as a daily iv bolus. This hypothesis was tested by comparing rates of decline of the third component of complement (C3) and of circulating neutrophils (PMN) in SLE patients with active disease with those of cynomolgus monkeys (CYN) undergoing induction of experimental IC-GN by means of a daily bolus infusion of antigen. It has previously been shown that, as antigen enters the circulation and forms circulating IC, C3 levels and circulating PMN decline acutely. Thus, acute changes in these parameters can be surrogates for the rate of antigen entry into the circulation. In the CYN undergoing induction of IC-GN (N = 11), infusion of the antigen (bovine gamma-globulin) over 10 min resulted in acute declines in C3 levels (25 +/- 6.6%; P = 0.0018 and PMN counts (59 +/- 9%; P < 0.0002). In addition, the CYN experienced the onset of acute respiratory distress and hypotension. By contrast, in patients with active SLE (N = 9), C3 and white blood cell counts measured at 24-h intervals did not change significantly, and episodes of acute hypotension or respiratory distress were not observed. In the CYN, the onset of visible vasculitic lesions in the omentum were also documented within minutes of the infusion of bovine gamma-globulin. The rapidity of onset of these vascular lesions suggests that the tempo at which lesions develop in experimental models of IC disease is faster than that of naturally occurring IC diseases. It was concluded that, in naturally occurring IC diseases, antigen probably enters the circulation slowly over prolonged periods of time, rather than as large boluses over short periods of time, as in traditional experimental models of IC-GN. Thus, models of IC-GN involving a daily bolus infusion of antigen may not be clinically relevant, particularly when IC clearing mechanisms are tested, because the efficiency of these mechanisms may be markedly influenced by the rate at which IC form in the circulation.

Animals↗
PubMed1988

Skin circulation in the nipple after reduction mammaplasty by upper and lower glandular resections.

Avascular necrosis of the nipple is a serious complication of reduction mammaplasty with nipple transposition. A study was undertaken to measure the skin circulation in the nipple before, during and after this operation. In 14 patients undergoing a reduction mammaplasty according to the method of Strömbeck, the skin circulation was measured in 25 breasts with laser doppler flowmetry (LDF) and fluorescein flowmetry (FF). LDF showed that the skin circulation increased after de-epithelialization to 204.4 +/- 31.0% of the preoperative value (100%) (mean +/- SEM, p less than 0.01). After the upper and lower glandular resection the circulation was reduced to 90.7 +/- 12.3% of the preoperative value. The division of the lateral pedicle did not affect the circulation. After the skin had been sutured, the circulation was 71.5 +/- 9.1% of the preoperative value (p less than 0.01). One to four days postoperatively the circulation was 100.3 +/- 13.2% of the preoperative value. At FF uniform fluorescence was observed in the nipple postoperatively in all patients but two, in whom avascular necrosis later developed. Our results thus show that the circulation in the nipple after reduction mammaplasty by the Strömbeck method is adequate and that it is safe to divide the lateral dermal pedicle.

Adult↗
PubMed1996

Influence of the site of skin incision on the circulation in the nipple-areola complex after subcutaneous mastectomy in breast cancer.

Necrosis of the skin resulting from impaired perfusion is one possible complication of subcutaneous mastectomy. The aim of this study was to evaluate the influence of two differently sited skin incisions on the circulation in the nipple-areola complex and in the surrounding skin. Sixty-nine patients with invasive breast cancer underwent subcutaneous mastectomy and immediate reconstruction with a subcutaneously placed prosthesis. In 26 of them a "lazy-S"-shaped horizontal lateral incision was made, and in 43 patients a transverse incision 1.5 cm above and parallel to the submammary fold. The skin circulation was measured by two methods, laser Doppler flowmetry (LDF) and fluorescein flowmetry, two or three days postoperatively. The skin circulation in the nipple-areola complex and in the skin 2 cm above the complex was the same irrespective of which of the two incisions was used, both by LDF and fluorescein flowmetry, but 2 cm below the complex fluorescein flowmetry showed 36% lower circulation in the submammary incision group than in the group with a lazy-S incision (p < 0.01), in contrast to LDF, which did not show any differences between the incisions. The circulation measured by LDF was higher in all three areas both with the lazy-S incision and with the submammary incision than in the opposite untreated breast. With fluorescein flowmetry there was a corresponding increase by 36% (p < 0.01) below the complex in the lazy-S incision group. There was no skin necrosis. In conclusion, the site of the skin incision used in this study did not influence the circulation in the nipple-areola complex or in the skin 2 cm above the complex as measured by LDF and fluorescein flowmetry. However, there was a reduction of the superficial circulation as measured by fluorescein flowmetry 2 cm below the complex in the submammary incision group. The increased circulation in the breast operated on was probably the result of traumatic hyperaemia.

Adult↗
PubMed2003

[Specific features of circulation in aorto-iliac arterial occlusion].

On occlusion of aorto-iliac segment arteries the collateral circulation ensures an effective compensation of circulation in lower extremities and pelvic organs. The Doppler characteristics of the circulation in visceral and collateral ways of circulation are the subject of the study. The power of ultrasound duplex scanning to evaluate the regional hemodynamics on atherosclerotic occlusion of aorto-iliac segment vessels has been proved. The Doppler parameters of circulation in upper (UMA) and lower (LMA) mesenteric arteries and internal iliac artery (IIA) on high, moderate an low occlusion of abdominal part of aorta (APA) and on unilateral occlusion of iliac arteries have studied. Depending on the level and grade of extension of occlusion of main arteries the collateral circulation may increase in two or three times. Comparing volumetric velocity of circulation (VVC) in UMA and LMA in control group and in patients with low occlusion of APA an increase of VVC in the artery that has an opening situated directly near the proximal site of occlusion were revealed. These results are the evidence of functional remodelling of regional hemodynamics and of the presence of resources of collateral circulation on occlusional and stenothic lesion of aorto-iliac segment arteries.

Aged↗
PubMed2004

Incisions for cochlear implant flaps and superficial skin temperature. Skin temperature/blood circulation in CI flaps.

Healing and integration of a cochlear implant is largely influenced by good blood circulation in the covering skin, which, on the other hand, is closely correlated to skin temperature. Measuring superficial flap temperatures by thermography is an easy way to get some clues about the corresponding blood supply. These data should allow some implications for the design of skin flaps in cochlear implant surgery. In 15 patients thermography was carried out prior to and after cochlear implantation, using the Agema 550 Thermovision system. It was evident, that the anatomic courses of the major superficial arteries were represented by areas of increased temperature. The pattern of temperature distribution may allow some conclusions concerning site and shape of surgical incisions. From our data we concluded, that most types of incisions do not interfere too much with the arterial blood supply. However, some types like the extended retroauricular C-incision may eventually cause problems. Our data suggest, that the straight or slightly curved vertical retroauricular incision causes the least impairment of blood circulation. After surgery, directly along the incisions (and later along the scars) temperature was diminished, indicating reduced blood circulation. In our series, the thickness of the implant did not impede blood circulation significantly. So far, we could not examine patients with local circulation disorders. Probably local scars, skin atrophies, angiopathies etc. may present typical patterns of temperature distribution, which require individual design of skin flaps. Thermography is an easy method which can give impressions of local blood circulation in skin flaps. If the courses of the major arteries and their branches are respected, blood circulation within the flap should not be problematic. Thermography is likely to help designing optimal flaps in cases with impeded blood circulation e.g. by pre-existing scar formations.

Atrophy↗
PubMed2004

[A new approach for studying the retinal and choroidal circulation].

One advantage of advanced computer technology is the high throughput with which the retinal and the choroidal circulation can be evaluated from new aspects. To study the choroidal circulation, we first reevaluated indocyanine green video angiography to improve the visualization of indocyanine green (ICG) images, then applied computer technology to analyze images obtained by an ICG video camera system. We also developed a new instrument to measure oxygen saturation levels in the fundus using spectral retinal imaging technology. I. Choroidal circulation. 1. Reevaluation of ICG video camera system: For this purpose, the bio-chemical nature of ICG was studied. 1) Spectral absorption of ICG: The peak absorption of ICG in distilled water was 780 nm as measured with a spectrophotometer. Its maximum absorption shifted from 780 nm to 805 nm after gradually mixing ICG with human serum protein. Conjugation time of ICG as well as fluorescein sodium with human serum protein was then measured by a stopped flowmeter. It was found that fluorescein sodium conjugated with human serum protein within a few milliseconds, while ICG required more than 600 seconds before equilibrium of the binding was reached. From these observations, we developed a new ICG video system with dual light sources; one, a 780 nm diode laser for the early dye filling phase, and the other, a 805 nm diode laser for the later phase of ICG angiography. 2) Binding properties of ICG in human blood: Blood samples were obtained from three healthy volunteers after intravenous administration of ICG. The resulting plasma samples were fractionated by agarose gel immunoelectrophoresis and polyacrylamide gel DISC electrophoresis. The electrophoretic pattern obtained by each method was observed with an ICG fundus video system. We also studied the affinity of ICG for lipids that are common molecular components of lipoproteins such as high-density lipoprotein (HDL) and low-density lipoprotein (LDL). Four kinds of ICG solutions mixed with phospholipid, free cholesterol, esterified cholesterol, and triacrylglycerol were observed with the ICG fundus video system. Both electrophoretic studies showed that ICG bound intensely to HDL and moderately to LDL, and only the solution with phospholipid fluoresced brightly when observed with the ICG fundus video system. 2. Residual fundus ICG fluorescence: Residual fundus fluorescence observed in the late phase of ICG angiography may be delineated differently in normal subjects and in patients with age-related macular degeneration (ARMD). We performed ICG angiography on 8 normal subjects aged below 36 years (8 eyes), 9 normal subjects aged above 62 years (9 eyes), and 21 patients with ARMD aged 50 to 88 years (37 eyes). The intensity and pattern of fluorescence from angiograms obtained in the ultra-late phase, 24 hours after dye injection, was recorded and analyzed. In the ultra-late phase, 95% of ARMD eyes with choroidal neovascularization (CNV) showed geographic hypofluorescent lesions. These hypofluorescent lesions occurred in 73% of ARMD eyes without CN, while age-matched normal subjects had no hypofluorescent lesions. The mean intensity of fluorescence in the normal elder subject group was significantly higher than that seen in the normal younger subject group. These findings may reflect aging change and bio-distribution of lipid on the Bruch-RPE complex. 3. The early dye filling pattern of the choroid: We performed ICG angiography on 10 healthy young volunteers aged 22 to 26 years (23.4+/-1.3; mean+/-standard deviation) using an improved ICG video camera system. ICG (50 mg) dissolved in 2 ml in distilled water was injected through the antecubital vein. Although the choroidal dye filling varied among subjects, it always began in the macular area. In the 10 subjects, initial dye filling had two patterns: reticular (n=8) and flush (n=2). The choroidal circulation filled completely before the retinal circulation did. Bright fluorescence in the macula and fast blood flow may be correlated with ample blood volume and abundant blood vessels in the macular area. 4. The spreading pattern of ICG fluorescence in the choroid: The ICG images obtained for observing the early dye filling pattern of the choroid were further processed with a computer-assisted image analyzer. Subtracted images were made using the early ICG frames with a time interval of 0.12 second. Ninety frames of time-sequential images for 3 seconds starting from the initial dye appearance in the choroid were prepared to construct an animated image. In the initial phase of eye filling, patchy fluorescence appeared in the fovea. The fluorescence then spread centrifugally in all directions in a wave-like pulsatile manner towards the peripheral fundus with increasing brightness. Thus an animated video of subtracted images allowed us to evaluate flow dynamics at the level of the choriocapillaris. Using this new approach, pathogenic involvement of choroidal circulation in varied chorioretinal diseases such as central serous chorioretinopathy can be studied with precision. II. Retinal circulation. We developed a new device to study the oxygen saturation (OS) levels in a wider fundus area. We call this device a spectral retinal image (SRI) system. We are pursuing the possibility of this instrument being in clinics to evaluate chorioretinal diseases. 1. Introduction of the device: The instrument consists of a Sagnac interferometer that has been mounted on top of a fundus camera, and a software module which consists of an acquisition module and an analysis module. The image acquisition process takes 6 seconds during which the fundus is illuminated by the white incandescent light of the fundus camera at the regular power settings. OS values in each pixel of the fundus image with a 35-degree view can then be estimated from the respective spectrum that is obtained by Fourier-transforming the interferometer signals. Each OS value is represented by a specific color, and each pixel of the fundus image is painted accordingly. 2. Clinical applications. 1) Control study: OS levels of both retinal arteries and veins within a 1 disc diameter (DD) area around the disc were measured from 20 SRIs obtained from 10 healthy volunteers, and were 96.65+/-3.30% and 56.05+/-4.69%, respectively. Then 30 healthy volunteers were recruited for further study in which the OS values were calculated in five retinal regions: (1) juxta-papillary area within 1.75 DD, (2) fovea within 1.0 DD, (3) papillomacular region within 1.0 DD, (4) superior area of the posterior fundus within 1.0 DD, and (5) inferior posterior area of the posterior fundus within 1.0 DD. The OS level of the juxta-papillary area was the highest, while that of the fovea was the lowest and the other three posterior retinal regions were in the middle. Thus OS levels differed at various areas in the retina with statistical significance. In spite of abundant choroidal circulation in the fovea, the overlying retina may have a relative by low oxygen level. As the retinal pigment epithelium may be efficient enough to block the effect of the choroid optically, our results may indicate that the OS levels represent the OS of the retina. 2) Measurement of OS levels in eyes with retinal circulatory disturbances: Eleven eyes of 10 patients with central retinal vein occlusion (CRVO), which showed various degrees of severity, and 4 fellow unaffected eyes of selected patients were examined by both fluorescein angiography (FAG) and the new SRI system. The fluroescein angiograms were correlated with OS maps that were calculated from the SRI. OS grading demonstrated by OS maps correlated well with severity of CRVO, as estimated by FAG. Thus our SRI system is noninvasive with reproducible results, and may prove to be a useful clinical tool to evaluate the degree of retinal ischemia. 3) Measurement of OS levels in eyes with glaucoma: Forty-seven eyes with open angle glaucoma (OAG) of 47 patients and 21 eyes of 21 age-matched normal subjects were recuited for the study. Twelve eyes with low-tension glaucoma (LTG) were included in the OAG eyes and the rest of the OAG eyes had primary OAG. All patients and normal subjects were examined by SRI. Visual field tests for OAG eyes were done with a Humphrey Field Analyzer using the 30-2 program, Swedish interactive threshold argorithm (SITA). OS levels in the retina at 5 different points: superior, inferior, superio- and inferio-temporal, and nasal region within a juxta-papillary area of 200 microm in diameter were calculated from the SRI. OS levels of retinal arteries were also measured and there were no significant differences between OAG and the control group. OAG eyes showed reduced OS levels in the inferio-temporal retina with statistical significance. This observation was more prominent in LTG eyes. The reduced OS levels observed in OAG eyes correlated well with mean deviation (MD) and the sum of total deviation of the 17 points in corresponding areas in the visual field analysis.

Adult↗
PubMed1991

[Determination of circulating antigen in cysticercosis patients using McAb-based ELISA].

For the first time, the determination of circulating antigen in patients with cysticercosis using specific monoclonal antibody against cysticercus antigen (CCyl) based on inhibitive ELISA was reported. The circulating antigens were detected in the sera from 83 patients with cysticercosis, the positive rate being 71.1%. The range of the detectable serum antigen concentrations was 0.16-128 micrograms/ml. In 41 cases of cysticercosis patients, circulating antigens were determined in both sera and cerebrospinal fluids, the positive rates being 68.3% and 78% respectively, the total positive rate being 90.2%. In 114 sera from normal persons, circulating antigen was absent. In 30 sera from patients with hydatidosis, 30 with clonorchiasis, 20 with schistosomiasis japonica, 24 with paragonimiasis, and 5 sera collected from non-parasitosis patients, serum circulating antigen was not detectable. In another 10 non-parasitosis patients, circulating antigen was not found in cerebrospinal fluid. After chemotherapy for one half to one year, in 21 out of 23 cases of cysticercosis patients, the circulating antigen levels in sera dropped to zero, except for two cases having an antigen level of 0.64 micrograms/ml and 1.6 micrograms/ml, respectively. Our results showed that the determination of the circulating cysticercus antigen was very specific for the diagnosis of active infection of cysticercosis and could be used as a rational tool in monitoring the effectiveness of chemotherapy.

Animals↗
PubMed1990

The relative contribution of individual osseous circulations to diaphyseal cortical blood supply.

The potential contributions of periosteal, nutrient (medullary), and epiphyseo-metaphyseal circulations, respectively, to cortical blood supply have been investigated by isolating each using a diaphyseal segment model. The periosteal circulation was isolated by creating and nailing a 2-cm segment of the adult rabbit tibial diaphysis. The medullary circulation was isolated by external application of a silastic sheath to a diaphyseal segment. The epiphyseo-metaphyseal circulation was isolated by combining both techniques. The residual potential routes of blood supply to each isolated segment were studied by arterial radiography and by histology in a postmortem study and in a survival study at various times up to 4 weeks after the isolation procedure. Both centrifugal and centripetal arterial supply were observed in the postmortem study. In the survival study, cortical arterial perfusion was observed up to 4 weeks following isolation of the periosteal circulation but only up to 2 weeks following isolation of the nutrient (medullary) circulation. At 4 weeks, the segment was not perfused when supplied only by the epiphyseo-metaphyseal system. It would appear, therefore, that the periosteal circulation provides a potential source of arterial supply to the diaphyseal cortex. Furthermore, an intact periosteal circulation seems to be necessary if an isolated segment of cortical bone is to continue to be adequately perfused with blood.

Angiography↗
PubMed1988

Human repetitive and unique sequences coexist in a large circulating DNA species found in cryoprecipitates from SLE patients.

Cryoprecipitates from systemic lupus erythematosus (SLE) patients with high levels of anti DNA antibodies show a sharply migrating large circulating DNA species of about 17-20 kb (M. Rieber et al., Clin. exp. Immunol. (1986) 66, 61). We have now used Southern blot analysis of circulating DNA from different individuals to analyse the relative cross-hybridization of circulating DNA from different individuals, as well as their homology with genomic DNA from different species. Molecular hybridization showed significant homology of the various circulating DNA examined, only with human genomic DNA, but limited cross-reactivity among circulating DNA from different individuals. This suggests that the circulating DNA is composed of sequences repeated in human genomic DNA and by specific sequences unique to circulating DNA from some individuals. Our data suggests the possibility of using probes derived from the specific sequences now reported in the circulating DNA, in gene typing and in the analysis of susceptibility to disease.

Base Sequence↗
PubMed1984

[Studies on the circulating antigens in murine toxoplasmosis].

The appearance of circulating antigens in mice and rats infected with Toxoplasma gondii RH strain was observed by a counterimmunoelectrophoresis. The results were summarized as follows: In the group of mice intraperitoneally inoculated 10(6) tachyzoites, the circulating antigens appeared from 2 days after inoculations until die. Specific antibodies to this protozoa measured by a latex agglutination test were not detected. Since the circulating antigens were also detected in the groups of mice treated with cyclophosphamide or irradiation of X-ray before intraperitoneal inoculation of 10(6) tachyzoites, it was thought that the circulating antigens were derived from the active proliferation of protozoa, not from the destruction of protozoa by immune-lysis. In the group of mice subcutaneously inoculated 10(6) tachyzoites, the circulating antigens appeared from 5 days after inoculations until die. The specific antibodies also elevated at the same time. This result indicated that the substances of circulating antigens were different from the antigens coated on the particle for the latex agglutination test. Rats resisting to Toxoplasma gondii infections were intraperitoneally inoculated 5 X 10(7) tachyzoites. The circulating antigens did not appear in all rats, but the production of specific antibodies was observed. Sensitive methods such as a enzyme-linked immunosorbent assay and a radioimmunoassay for detection of the circulating antigens may be useful tools for diagnosis of acute toxoplasmosis.

Animals↗
PubMed1981

Nephritogenic immune reactions involving immune complex formation in the circulation and in situ within the kidney.

The circulating immune complex (IC) mechanism of renal and vascular injury is now well established based on observations in experimental serum sickness in animals and detection of circulating and localized IC of known antigen and antibody content in glomerulonephritis (GN) in man. Studies continue on the factors responsible for formation and vascular deposition of circulating IC. Utilization of assays to detect circulating IC has revealed that some patients with chronic presumed IC GN have no unusual amount of circulating IC. The possibility that nephritic individuals may handle relatively normal amounts of circulating IC in a nephritogenic fashion points out the need to study host and genetic factors in the development of IC GN. Observations in experimental animals have demonstrated the nephritogenic potential of the direct reaction of antibody with antigens, either structural in nature or "planted" within the glomerulus in a discontinuous pattern. This suggests that some GN previously thought to be from deposition of circulating IC IC by the pattern of irregular Ig accumulation on immunofluorescence study might be the product of a direct reaction of antibody with glomerular capillary wall antigens. Models of such reactions involving nonclassic glomerular basement membrane (GBM) glomerular capillary wall antigens are being identified in animals and sought in man. Finally, the reaction of antibodies with foreign materials that are first trapped or "planted" within the glomerulus can be nephritogenic in animal models and conceivably in man. The local nephritogenic immune reaction within the glomerulus should not distract from the circulating IC mechanism but rather expand our ideas of how the immune system can damage the kidney.

Animals↗
PubMed1994

In vivo synergy between recombinant human stem cell factor and recombinant human granulocyte colony-stimulating factor in baboons enhanced circulation of progenitor cells.

Recombinant human stem cell factor (rhSCF) and recombinant human granulocyte colony-stimulating factor (rhG-CSF) are synergistic in vitro in stimulating the proliferation of hematopoietic progenitor cells and their precursors. We examined the in vivo synergy of rhSCF with rhG-CSF for stimulating hematopoiesis in vivo in baboons. Administration of low-dose (LD) rhSCF (25 micrograms/kg) alone did not stimulate changes in circulating WBCs. In comparison, administration of LD rhSCF in combination with rhG-CSF at 10 micrograms/kg or 100 micrograms/kg stimulated increases in circulating WBCs of multiple types up to twofold higher than was stimulated by administration of the same dose of rhG-CSF alone. When the dose of rhG-CSF is increased to 250 micrograms/kg, the administration of LD rhSCF does not further increase the circulating WBC counts. Administration of LD rhSCF in combination with rhG-CSF also stimulated increased circulation of hematopoietic progenitors. LD rhSCF alone stimulated less of an increase in circulating progenitors, per milliliter of blood, than did administration of rhG-CSF alone at 100 micrograms/kg. Baboons administered LD rhSCF together with rhG-CSF at 10, 100, or 250 micrograms/kg had 3.5- to 16-fold higher numbers per milliliter of blood of progenitors cells of multiple types, including colony-forming units granulocyte/macrophage (CFU-GM), burst-forming unit-erythroid (BFU-E), and colony-forming and burst-forming units-megakaryocyte (CFU-MK and BFU-MK) compared with animals given the same dose of rhG-CSF without rhSCF, regardless of the rhG-CSF dose. The increased circulation of progenitor cells stimulated by the combination of rhSCF plus rhG-CSF was not necessarily directly related to the increase in WBCs, as this effect on peripheral blood progenitors was observed even at an rhG-CSF dose of 250 micrograms/kg, where coadministration of LD rhSCF did not further increase WBC counts. Administration of very-low-dose rhSCF (2.5 micrograms/kg) with rhG-CSF, 10 micrograms/kg, did not stimulate increases in circulating WBCs, but did increase the number of megakaryocyte progenitor cells in blood compared with rhG-CSF alone. LD rhSCF administered alone for 7 days before rhG-CSF did not result in increased levels of circulating WBCs or progenitors compared with rhG-CSF alone. Thus, the synergistic effects of rhSCF with rhG-CSF were both dose- and time-dependent. The doses of rhSCF used in these studies have been tolerated in vivo in humans.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1991

Influence of minimal angiographic visible collateral circulation on myocardial function during PTCA.

The potential protective role of angiographically visible minimal collateral circulation in diagnostic angiograms, not reaching or filling the target vessel (RENTROP class 1), on myocardial function during percutaneous transluminal coronary angioplasty (PTCA), was studied in two groups of patients undergoing elective PTCA of the left anterior descending artery (LAD). In the first study group consisting of 22 patients, influence of collateral circulation class 1 on left ventricular regional function was evaluated. In this group, 14 patients showed no angiographic collaterals and 8 patients showed collateral circulation class 1 in diagnostic angiograms. Increase of end-diastolic and end-systolic volume indices as well as decrease of global left ventricular function was not significantly different inpatients with and without such minimal collateral circulation. In patients without collaterals, the decrease of regional left ventricular function was significantly more pronounced in the left anterior length segment (p less than 0.05) and a trend was observed in the anterolateral (p = 0.059) and apical (p = 0.053) segments. In a second group, consisting of 29 patients, hemodynamic parameters were measured and, in addition to grading of collateral circulation in diagnostic angiograms, angiographically visible collateral circulation was estimated during occlusion of the LAD by injecting contrast materials into the right coronary artery. An increase of angiographically visible collaterals during the ischemic period of various degrees was documented in 26 (90%) of 29 patients. Combining patients of both study groups, increase in left ventricular end-diastolic pressure during ischemia was significantly higher (p less than 0.05) in patients without collaterals on diagnostic angiography (n = 34) than in patients with collateral circulation class 1 (n = 14).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1999

Comparison of coronary collateral circulation in diabetic and nondiabetic patients suffering from coronary artery disease.

BACKGROUND AND HYPOTHESIS: Although it is well established that diabetes mellitus (DM) induces more severe coronary artery disease (CAD), it is not known whether it contributes to the development of coronary collateral circulation. The present study examines coronary collateral circulation in diabetic and nondiabetic patients with angiographically verified CAD. METHODS: The study group consisted of 463 diabetic patients (382 men, 81 women) with a mean age of 60.3 +/- 8.8 years, and 227 nondiabetic subjects (159 men, 68 women) with a mean age of 59.2 +/- 9 years. The extension and functional capacity of coronary collateral circulation was assessed according to the Cohen and Rentrop grading system of 0 to III. RESULTS: We found that diabetic patients had grade III collateral circulation more frequently than nondiabetic subjects (13.2 vs. 8.5%, p < 0.01). This finding was even more pronounced in diabetic men aged < 55 years compared with both nondiabetic men (20 vs. 3.4%, p < 0.001) and diabetic women (20 vs. 2.2%, p < 0.001). Grade III collateral circulation was found to develop mainly at the left anterior descending (LAD) coronary artery and the right coronary artery (RCA), where complete occlusions of coronary arteries usually occur. CONCLUSIONS: Diabetic patients with CAD develop more extensive coronary collateral circulation than nondiabetic subjects, especially men aged < 55 years. The collateral circulation mainly develops at the LAD and RCA.

Adult↗
PubMed1996

Relation between preexistent coronary collateral circulation and the incidence of restenosis after successful primary coronary angioplasty for acute myocardial infarction.

OBJECTIVES: The purpose of this study was to test the hypothesis that the incidence of restenosis after primary percutaneous transluminal coronary angioplasty for acute myocardial infarction is largely influenced by the preexistent coronary collateral circulation to the infarct-related coronary artery. BACKGROUND: The occurrence of restenosis after coronary angioplasty is the most serious limitation of this procedure. However, prediction of restenosis is difficult. Severe preexistent stenosis of the infarct-related coronary artery causing the development of collateral circulation may result in a high frequency of restenosis. METHODS: The study group consisted of 152 consecutive patients undergoing primary coronary angioplasty within 12 h after the onset of a first acute myocardial infarction. Of this group, 124 patients were angiographically followed up during the convalescent period of infarction and were classified into two groups according to the extent of preexistent collateral circulation to the infarct-related coronary artery. RESULTS: Restenosis occurred in 26 (38%) of 69 patients with poor or no collateral circulation (group A) in contrast to 35 (64%) of 55 patients with good angiographic collateral circulation (group B, p < 0.005). The frequency of preinfarction angina was significantly lower (p < 0.05) in group A (26% [18 of 69]) than in group B (44% [24 of 55]). CONCLUSIONS: These findings indicate that the presence of well developed collateral circulation to the infarct-related coronary artery predicts a higher frequency of restenosis after primary coronary angioplasty. The difference in restenosis rates observed between the patients with and without good collateral circulation probably reflects the impact of underlying severity of stenosis on the long-term outcome after coronary angioplasty.

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