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PubMed1981

Non-frozen preservation of committed hematopoietic stem cells from normal human bone marrow.

We examined the optimal conditions for maintaining normal human hematopoietic stem cells without cryopreservation. The effects of serum, HEPES, CPD and storage temperature were studied. Stem cell integrity (CFU-c, CFU-e, and BFU-e) was optimally maintained when the bone marrow cells were suspended in a medium containing 40% fetal calf serum, 25 mM HEPES, and 12.28% CPD and maintained at 4 degrees C. For example, under these storage conditions the recovery of functionally intact early erythroid stem cells, BFU-e, was 84% after 2 days, 44% after 4 days and 12% after 7 days. These results indicate that non-frozen short-term storage of human bone marrow may be of clinical utility in bone marrow transplantation.

Cell Survival↗
PubMed1980

Decreased ionized calcium during therapeutic plasma exchange pheresis and platelet pheresis.

Marked reductions in ionized calcium were observed in normal donors undergoing platelet pheresis using acid-citrate dextrose formula A (ACD)-A) anticoagulant, and in patients undergoing therapeutic plasma exchange pheresis using citrate phosphate dextrose (CPD)-ABO compatible plasma. Donors showed a greater tendency to symptoms of hypocalcemia, although patients receiving CPD plasma demonstrated lower values of ionized calcium. It is suggested that there may be important differences in the availability of calcium from plasma containing these two anticoagulants.

Blood Donors↗
PubMed1995

DNA repair in the MYC and FMS proto-oncogenes in ultraviolet light-irradiated human HL60 promyelocytic cells during differentiation.

In order to better understand the role of transcription in cellular processing of damage in specific DNA sequences, we have used an in vitro differentiation system to modulate the activity of the MYC gene. When human HL60 promyelocytic cells differentiate in vitro, the transcriptional activity of the MYC gene is down-regulated. We have shown that in the expressed MYC gene, 56% of UV-induced cyclobutane pyrimidine dimers (CPDs) are removed within 18 h and the transcribed strand is selectively repaired. However, late in differentiation, when the MYC gene is maximally down-regulated, only 15% of the CPDs are removed within the same period. During early differentiation, the MYC gene is regulated by a block to transcription elongation at the 5' end of the first intron. Our results reveal no significant difference in the rate of CPD removal between the restriction fragments upstream and downstream of this elongation block. Furthermore, both strands of each fragment exhibit similar repair characteristics. In contrast, the constitutively expressed FMS gene exhibits proficient removal of CPD in both the differentiated and undifferentiated cells. Furthermore, the repair appears to be more proficient at the 5' end (exon 1) than in the 3' end of the gene about 35 kilobases downstream from exon 1. Since efficient repair of the active FMS gene is maintained in the differentiated cells the loss of repair competence seen in MYC is more likely associated with its reduced transcriptional activity than with a decrease in the overall repair capacity of the terminally differentiated cells.

Cell Differentiation↗
PubMed1994

Penetration of a dentin bonding agent into dentin.

PURPOSE: To examine how the priming agents of Scotchbond Multi-Purpose (SMP) influenced the wettability of collagen in the demineralized zone and hence the penetration and adaptation of its bonding monomers. MATERIALS AND METHODS: Freshly extracted bovine teeth were ground to dentin with SiC paper. SMP and Z100 resin were used. Shear bond testing was performed as well as scanning electron microscopic evaluation. RESULTS: In contrast to the manufacturer's instructions, a 26.3% increase in shear bond strength was obtained when a second coat of priming agent was applied. This increase was statistically significant at the 5% level of confidence. SEM examination of failed conventionally air dried (CAD) specimens showed the presence of voids in the demineralized layer. SEM examination of failed specimens prepared by a critical point drying (CPD) technique showed that these voids were filled with collagen fibrils. The CPD technique also clearly showed that collagen fibrils were incorporated in the unfilled resin. Although priming agents appear to facilitate the penetration of unfilled resin into the demineralized layer and the dentin tubules, areas of unincorporated collagen fibrils can be seen even after two or more applications of the priming agent.

Analysis of Variance↗
PubMed1976

Cryobiology overview of red cell preservation: achievements and prospective.

Preserved red cells are transfused to improve the delivery of oxygen to tissue. The preserved red cells must circulate to increase the red cell volume and improve the oxygen carrying capacity. The correlation between oxygen transport function and the red cell 2,3 DPG level has been known since 1967. but it was only recently that the importance of the oxygen delivering capacity of transfused red cells during the immediate posttransfusion period became apparent. Red cells with low 2,3 DPG levels and increased affinity for oxygen will increase cardiac output and/or decrease venous pO2 for at least 4 hours after transfusion. Oxygen transport function is maintained longer in red cells stored in CPD than in ACD-stored red cells. Supplementation of CPD red cells with inosine, ascorbate; dihydroxyacetone and other substances helps to maintain the oxygen transport function during storage at 4 C. Liquid-stored red clls can be biochemically modified before freeze-preservation to increase the 2,3 DPG levels to to 1-1/2 to 2 times normal; these red cells have decreased oxygen affinity. The red cells have acceptable posttransfusion survival and improved oxygen releasing capacity for at least 72 hours after transfusion. The well-being of certain patients may be placed in jeopardy of they are given preserved red cells with increased affinity for oxygen. The patient may not be able to meet the accompanying demand for increased blood flow, and the venous-capillary oxygen tension may fall to a critical level. Clearly, patients in hemorrhagic and septic shock, those subjected to extracorporeal circulation during cardiac surgery, and anemic patients with myocardial or cerebrovascular insufficiency are best treated with red cells that have 150% normal 2,3 DPG levels.

Adenosine Triphosphate↗
PubMed1994

A survey to assess the ultrastructural preservation of fixed biological samples after air-drying from tetramethylsilane.

A scanning electron microscope (SEM) survey assessed the quality of ultrastructural preservation of a wide range of tissues from the laboratory rat and from a limited number of botanical and fly-larval samples, air-dried from tetramethylsilane (TMS) after chemical fixation and dehydration. Comparisons were made with critical point drying (CPD) and air-drying from acetone. CPD produced good results in all cases. TMS gave acceptable results with 75%, and acetone with 31%, of rat tissues. Air-drying was unacceptable for the botanical and fly-larval samples. It is concluded that air-drying from TMS is generally useful for mammalian tissues in preparation for the SEM.

Animals↗
PubMed1994

[Predonation of autologous blood for up to 6 weeks in MAP solution prior to elective cardiac surgery].

Predonation of autologous blood was performed by means of MAP solution prior to elective cardiac surgery. MAP solution made it possible to store in the fashion of fluid for 6 weeks. In twenty-three patients, total 39 times, predonation of autologous blood was performed prior to the elective cardiac surgeries. The mean volume of predonated blood was 583 ml (400-1200 ml)/case with MAP solution and 165 ml (0-400 ml)/case with conventional CPD solution, and the mean volume of total predonated blood was 748 ml (400-1600 ml)/case. The mean of the maximum duration of MAP predonate blood storage in individual cases was 25 days. Homologous blood transfusion was required in three cases. Two of the three cases had total aortic arch replacement under selective cerebral perfusion and the remainder was 76 year-old-man with unstable angina. In twenty cases (87%), any homologous blood transfusion was not performed throughout their clinical course. Twenty (95%) cases of 21 conventional cardiopulmonary bypass operation cases, except two selective cerebral perfusion cases, could successfully avoid homologous blood transfusion. To conclude, by using MAP solution, it became possible to take the longer period for predonation prior to elective surgery up to 6 weeks, compared with that in conventional way of storage by means of CPD solution. It seems worth-while to use MAP solution in order to take more predonated blood for avoiding homologous blood transfusion in elective cardiac surgery as far as possible.

Adenine↗
PubMed1993

Differentiation and polypeptide expression in human papilla and dermal fibroblasts in vitro.

Proliferation and differentiation of human scalp hair follicle papilla fibroblasts (PF) in the anagenic stage of development and of neighboring dermal fibroblasts (DF) of the same donor were studied with stem cell system-specific methods in primary and secondary populations in in vitro systems. Both populations differentiate along the sequence of mitotic fibroblasts (MF) MF I-MF II-MF III and postmitotic fibroblasts (PMF) PMF IV-PMF V-PMF VI-PMF VIIa/PMF VIIb, as described for fibroblast stem cell systems in general elsewhere (Bayreuther et al., Mutat. Res. 256, 233-242 (1991)). PF and DF populations are distinguished by a number of cell-biological parameters, like population dynamics, maximal cumulative population doublings (CPD), changes in cell type frequencies, changes in cloning efficiency as a function of the CPD level (CPDL) of mitotic mass population, in addition by distinct changes of cell type frequencies of postmitotic fibroblasts as a function of the duration of maintenance of postmitotic fibroblast population in stationary culture. Primary and secondary PFs express cell type-specific high molecular weight cellular polypeptides in the M(r) range of 190 to 270 x 10(3) and/or secrete cell type-specific low molecular weight polypeptides in the M(r) range of 27 to 28 x 10(3) as revealed by two-dimensional gel electrophoresis of [35S]methionine-labeled and [14C]proline-labeled polypeptides. These polypeptides are not expressed in the corresponding primary or secondary DF cell types. The expression of specific proteins in primary and secondary PF in vitro may correspond to specific functions of PF in vivo.

Adolescent↗
PubMed1993

The effects of daily-wear contact lenses on contrast sensitivity in selected professional and collegiate female tennis players.

Contrast sensitivity (CS) has recently emerged as an important predictor of visual performance. Few studies, however, have been published involving CS and its role in vision for sport. The purpose of this investigation was to determine if significant differences occurred in CS between female professional and collegiate tennis players who wore daily-wear soft contact lenses (N = 10) and those players who wore no corrective lenses (N = 10) in competition as measured by the Stereo Optical Optec 2000 Vision Tester. Subjects were between the ages of 18 and 37 years. Mean ages were 21.76 (+/- 4.018) and 25.40 (+/- 5.379) years for those wearing lenses and those not, respectively. Each subject was preliminarily screened for SVA-distance, lateral/vertical phorias, stereopsis, and color perception. All subjects were within accepted limits. CS was assessed at 1.5, 3, 6, 12, and 18 cycles per degree (cpd). Each subject was assessed monocularly; eye initially assessed was determined randomly. A 2 x 2 factorial analysis of variance (alpha = .05) was used to analyze data. No significant differences were found between eyes. Significant differences were found at 3, 6, 12, and 18 cpd. It may be concluded that those female professional and collegiate tennis players wearing no corrective lenses were significantly higher in CS at intermittent and high spatial frequencies than those who wore daily-wear soft contact lenses in competition.

Adolescent↗
PubMed1995

Varifocal contact lenses for the correction of presbyopia.

A Nissel +1.75 D PS45 lens' label power seems to be made up of about +0.75 D distance and +0.75 D near addition. There are individual variations which will depend on pupil size, corneal shape, lens position and ocular aberrations. When a +0.75 Bausch & Lomb U3 lens was used as a control, there was also a significant increase in 'accommodation' measured (+0.75 D), but this could not be explained. When two other lenses with an aspheric surface were studied, they also showed a near addition effect. In this supplementary study the changes were explained by changes in spectacle accommodation. A lens with two spherical surfaces did not show the expected increase in spectacle accommodation. Astigmatism, as a general rule, was not corrected by the PS45 lens, although the very occasional case did show some reduction. Visual acuity and contrast sensitivity at 8 cpd and 3 cpd were not significantly affected when compared to the control lens.

Accommodation, Ocular↗
PubMed1995

Treatment of peritoneal dialysis-associated peritonitis with continuous versus intermittent vancomycin/teicoplanin and ceftazidime in children: preliminary results of a prospective randomized trial. Members of APN Arbeitsgemeinschaft Paidiatrische Nephrologie.

A recent treatment update for continuous peritoneal dialysis (CPD)-associated peritonitis recommends first-line use of continuously or intermittently administered intraperitoneal vancomycin and ceftazidine. Teicoplanin has recently been introduced as a potentially less toxic alternative glycopeptide antibiotic. However, efficacy and safety have not been demonstrated for intermittent treatment schedules or for the use of teicoplanin in prospective studies. Therefore, a prospective trial on the treatment of CPD-associated peritonitis was started in 15 pediatric dialysis units using vancomycin or teicoplanin, in combination with ceftazidine. Vancomycin or teicoplanin was administered either continuously with each bag of dialysate for 10 days or as a single dose on days 1 and 8, and ceftazidime either continuously or in one bag of dialysate per day. Until December 31, 1994, 81 episodes of peritonitis including 16 relapses occurred in a cohort of 120 patients. The incidence of peritonitis was 1 episode/13.7 months, regardless of treatment modality [continuous ambulatory peritoneal dialysis (CAPD) or continuous cycling peritoneal dialysis (CCPD)]. Thirty-six (57%) primary peritonitis episodes were caused by staphylococci (21 Staphylococcus aureus, 15 coagulase-negative), 12 (19%) by gram-negative bacteria, 7 by other germs, and in 8 (13%) cases cultures remained sterile. Primary treatment response was achieved in 43/46 (93%) gram-positive and 4/12 (33%) gram-negative peritonitis episodes. Relapses occurred only with gram-positive bacteria (16/63, 25%). In cases of gram-positive peritonitis, no differences in primary response (25/25 vs 15/18) or relapse rates (10/36 vs 6/27) were observed between groups on continuous and intermittent treatment, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Bacterial Agents↗
PubMed1995

Mechanisms of platelet dysfunction and response to DDAVP in patients with congenital platelet function defects. A double-blind placebo-controlled trial.

To examine the impact of the underlying defective platelet mechanism on the response to 1-desamino-8-D-arginine vasopressin (DDAVP, Desmopressin), we studied the effect of intravenous infusion of 0.3 microgram/kg of DDAVP in a randomized double blind placebo-controlled trial with cross-over in 18 carefully characterized patients with congenital platelet defects (CPD) and BT > or = 9 min. Eleven patients had normal dense granule stores and normal thromboxane A2 (TxA2) production (Group I), 3 patients had normal granule stores but impaired TxA2 production (Group II), and 4 had delta-storage pool deficiency (Group III). DDAVP shortened BT at 50 min (DDAVP 14.6 +/- 2.2 vs placebo 19.6 +/- 2.3 min; n = 18; mean +/- SE; p = 0.003) and 4 h (17.0 +/- 2.2 vs 19.6 +/- 2.1 min, p = 0.055), and raised plasma FVIIIC and von Willebrand factor (vWF). At 50 min DDAVP shortened BT by > or = 5 min in 8 of 11 Group I patients (mean 9.7 +/- 1.3 vs 16.3 +/- 2.8 min; p < 0.008), 1 of 3 Group II patients (11.9 +/- 3.9 vs 17.7 +/- 6.6; p = NS) and none of Group III patients (mean 30 min both arms). Ten patients (Group I or II) were managed successfully during surgical procedures with DDAVP alone. We conclude that DDAVP shortens BT in majority of CPD patients with normal dense granule stores and suggest that BT response may be dependent on the underlying platelet defect. DDAVP is a useful modality in management of selected patients, particularly those with normal dense granule stores.

Bleeding Time↗
PubMed1996

Psychosocial factors and incidence of peritonitis.

It has been suggested that psychosocial (PS) factors may influence morbidity and mortality in chronically ill patients. However, investigators have not examined how PS factors affect specific medical problems in chronic peritoneal dialysis (CPD) patients. Sixty-eight patients maintained on CPD therapy were studied. PS testing included a self-rating form of patient-assessed quality of life (PaQOL), depression [Beck's Depression Inventory (BDI)], anxiety [Patient Rated Anxiety Scale (PRAS)], and assessment of physical symptoms (KDS-II). Peritonitis rates six months prior to PS assessment and six months after assessment were tabulated. The data show that during the study period patients with more than one episode of peritonitis compared to those with no episodes of peritonitis had: (1) significantly higher anxiety and physical symptom scores; (2) significantly lower PaQOL; and (3) higher depression scores, which did not reach statistical significance (p < 0.06). Whether higher peritonitis rates result in worse PS symptoms, or whether poor PS symptoms cause higher peritonitis rates needs to be determined with further investigations.

Adult↗
PubMed1996

Protein and calorie intake, nitrogen losses, and nitrogen balance in children undergoing chronic peritoneal dialysis.

We performed 22 nitrogen balance (NB) studies of three days' duration in 19 children (8.7 +/- 3.8 years) on chronic peritoneal dialysis (CPD) for 19.4 +/- 16.4 months. The dietary intakes were assessed by the double weighing method. Total nitrogen, protein, urea, and creatinine were analyzed in the dialysate and urine collected daily. Total nitrogen was also determined in the feces collected over the whole NB study period, using vegetable charcoal as a marker. The protein intake was 1.64 +/- 0.50 g/kg/day, corresponding to 126 +/- 40% of the recommended daily allowance (RDA) for normal children of the same age, and the calorie intake (diet+glucose from dialysate) reached 75 +/- 26% of RDA. Nitrogen losses were: 0.177 +/- 0.052 g/kg/day with peritoneal fluid and urine, and 0.028 +/- 0.018 g/kg/day with feces. The NB, positive in 17 out of 22 studies, ranged from -116 to +167 mg/kg/day (mean 44.0 +/- 66.2 mg/kg/day). A direct and significant correlation between NB and nitrogen intake (g/kg/day) (r = 0.562, p < 0.05) and total calorie intake (cal/kg/day) (r = 0.483, p < 0.05) has been observed. These data confirm the need to ensure in children on CPD an adequate nutritional intake, and further support the efforts to improve calorie intake.

Blood Proteins↗
PubMed1976

Nutritional deficiency, immunologic function, and disease.

Several experiments conducted by our group over a period of 6 years have shown that nutritional stress, especially protein and/or calorie deprivation, leads to many, often dramatic, changes in the immune responses of mice, rats, and guinea pigs. Chronic protein deprivation (CPD) has been shown to create an enhancing effect on the cell-mediated immune responses of these animals. Humoral responses under CPD conditions were most often found to be depressed, but sometimes were unaffected, depending on the nature of the antigen employed. Chronic protein deprivation, consistent with the pattern just mentioned, improved tumor immunity by depressing production of B-cell blocking factors, and, in at least one instance, resistance to development of mammary adenocarcinoma in C3H mice was associated with evidence of increased numbers of T suppressor cells. Profound nutritional deficits (less than 5% protein per total daily food intake) depressed both cellular and humoral immunity. Early, though temporary, protein deprivation caused a long-term depression of both cellular and humoral immunity also, with the humoral component being the first to recover. Manipulation of protein and calories was found to have a profound effect on certain autoimmune conditions. Diets high in fat and low in protein favored reproduction but shortened the life of NZB mice, whereas diets high in protein and low in fat inhibited development of autoimmunity and prolonged life. Chronic moderate protein restriction permitted NZB mice to maintain their normally waning immunologic functions much longer than mice fed a normal protein intake. Further, the low-protein diet was associated with a delay in development of manifestations of autoimmunity. Decreasing dietary calories by a reduction of fats, carbohydrates, and proteins more than doubled the average life span of (NZB X NZW)F1 mice, a strain prone to early death from autoimmune disease. Histopathologic studies using immunofluorescent microscopy revealed that the development of the renal lesions caused by the deposition of antigen-antibody complexes, which is so characteristic of these mice, was markedly delayed.

Anemia, Hemolytic↗
PubMed1997

Evaluation of mid-term stability of night vision tests.

BACKGROUND: Dark adaptation rate, scotopic retinal sensitivity and contrast sensitivity under mesopic conditions, but not visual acuity, have been shown to be directly related to the ability to identify military targets at night. These parameters can be used to select personnel for specific military tasks demanding excellent night vision, as well as to assess pharmacological effects on night vision. PURPOSE: To evaluate the mid-term (2 to 6-week period) stability of night vision tests based on assessment of the above parameters. METHODS: Dark adaptation rate, scotopic retinal sensitivity and contrast sensitivity under mesopic conditions were studied in 16 young volunteers during a 6-week period. RESULTS: Tests of scotopic retinal sensitivity (after 30 min of dark adaptation) exhibited high reproducibility and a low fluctuation rate, with a high correlation between values at week 0 and at 2-week intervals during the following 6 weeks of the study (rs (week 0 to week 6) = 0.81, p = 0.0001). The reproducibility of mesopic contrast sensitivity tests (average of 1.5, 3, 6 and 12 cycles per degree, (cpd)) was fair (rs (week 0 to week 2) = 0.67, p = 0.0045), whereas that of dark adaptation rate tests was poor. CONCLUSIONS: In view of the reproducibility characteristics of these night vision tests, assessment of night vision ability in pilots and military personnel, as well as assessment of pharmacological effects on night vision, may be based on scotopic retinal sensitivity (after 30 min of dark adaptation) and contrast sensitivity under mesopic conditions (average of 1.5, 3, 6 and 12 cpd).

Adult↗
PubMedDate not supplied

The Italian Registry of Pediatric Chronic Peritoneal Dialysis: a ten-year experience with chronic peritoneal dialysis catheters.

OBJECTIVE: To analyze the data from 347 peritoneal catheters implanted in 249 pediatric patients aged < or = 15 years at start of chronic peritoneal dialysis (CPD). DESIGN: Restrospective study of the data collected between 1986 and 1995, in 20 dialysis centers, from the Italian Registry of Pediatric Chronic Peritoneal Dialysis. Data collection for each pediatric catheter included: catheter type, site and technique of insertion, complications, duration, and reason for removal or replacement. RESULTS: Fifty catheters were inserted in patients under 2 years of age, 50 in patients aged 2 - 5 years and 247 in patients over 5 years of age. Catheter types included 307 (88.5%) Tenckhoff (286 double cuff, 21 single cuff) and 40 (11.5%), double-cuff, Valli-type catheters. All catheters were surgically implanted and omentectomy was performed in 83.5% of cases; the entry-site was in the midline in 136 cases (39.2%) and paramedian in 211 (60.8%). During 6076 CPD months we observed 274 catheter-related complications: 182 catheter infections (exit-site and/or tunnel infection), 23 leakages, 19 obstructions, 19 cuff-extrusions, 14 dislocations, 6 hemoperitoneum, 10 other (incidence of one complication every 21.8 dialysis-months). A significant reduction of catheter-related complications occurred in the last five years, compared with the first 5 years. One hundred and six catheters were removed due to catheter-related causes: infection (83 cases), obstruction (11), dislocation (4), outer-cuff extrusion (3), leakage (2), bowel incarceration (2), and bowel infarction (1). Catheter survival was 72.2% at 12 months, 52.3% at 24 months, 32.8% at 36 months, and 25.7% at 48 months. Significantly lower catheter survival was found in younger children (0 - 2 years) compared with two other age groups (2 - 5 years, and > 5 years). No significant correlation was found between catheter survival and catheter entry-site (midline vs paramedian). CONCLUSIONS: Catheter-related infections were confirmed to be the most common complication and most frequent cause of peritoneal catheter removal. In addition, catheter survival rate was worse in younger children, indicating that more effort should be made to improve peritoneal catheter survival particularly in this age group.

Adolescent↗
PubMed1996

Correlated confocal and intermediate voltage electron microscopy imaging of the same cells using sequential fluorescence labeling, fixation, and critical point dehydration.

Confocal laser scanning microscopy (CLSM) and intermediate voltage transmission electron microscopy (IVEM) each has its own particular advantages. CLSM can examine living cells, but is particularly useful when applied to cells that have been lightly fixed, permeabilized, and stained with fluorescent-labeled antibodies for localization of specific molecular species at the resolution of the light microscope while still in the hydrated state. IVEM provides much higher resolution images, but requires more drastic preparation procedures, including dehydration. This paper presents methods for combining these complementary approaches to examine exactly the same cells sequentially by CLSM and IVEM. Cells are grown in culture on sterile formvar films spread over gold index grids on cover glasses, which are mounted on larger cover glasses or microscope slides with spacers to prevent compression of the cells. Light and epifluorescence microscopy, and CLSM are performed concentrating on cells in grid openings. Then the grids are fixed with aldehydes followed by OsO4, dehydrated and critical point dried (CPD) from liquid CO2. Immediately following CPD, the grids are ready for examination in the IVEM. Low magnification (300-600x) survey images allow correlation of the IVEM images with the light microscopic images. In higher power images, structures that are fluorescent labeled can be related to corresponding regions in the IVEM images.

Animals↗