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Determination of circulating levels of insulin-like growth factor II (IGF-II) in swine.

A heterologous radioimmunoassay system was developed for the determination of circulating IGF-II concentrations in swine. The assay utilized a monoclonal antibody against human IGF-II (Amano Intl. Ez, VA) and bovine IGF-II (Monsanto Co., MO) as the cold standard and iodinated ligand. Serial dilutions of acid-ethanol extracted normal swine sera resulted in a curve which was parallel to the bovine IGF-II standard curve. Recovery of unlabeled standard added to extracted swine sera was 101%. Neither IGF-I nor insulin were capable of cross-reacting in this assay at levels up to 100-fold excess. Using this assay, serum IGF-II levels were determined to be significantly lower when subnormal growth hormone (GH) levels existed such as in hypophysectomized swine. However, in contrast to serum IGF-I concentrations, supranormal levels of porcine GH (pGH) did not elevate serum IGF-II concentrations after 13 wk of treatment in 25 kg hogs (initial body wt). In addition, serum IGF-II levels were reduced in fasted swine, despite a significant increase in circulating GH concentrations. Thus, although normal concentrations of GH are required for maintenance of physiological levels of IGF-II in swine, the mechanism for stimulation of IGF-II secretion is less GH-dependent than IGF-I.

Animals↗

Cortical origins of response time variability during rapid discrimination of visual objects.

In this paper, we use single-trial analysis of electroencephalography (EEG) to ascertain the cortical origins of response time variability in a rapid serial visual presentation (RSVP) task. We extract spatial components that maximally discriminate between target and distractor stimulus conditions over specific time windows between stimulus onset and the time of a motor response. We then compute the peak latency of this differential activity on a trial-by-trial basis, and correlate this with response time. We find, for our nine participants, that the majority of the latency is introduced by component activity which begins far-frontally 200 ms prior to the response and proceeds to become parietally distributed near the time of response. This activity is consistent with the hypothesis that cortical networks involved in generating the late positive complexes may be the origins of the observed response time variability in rapid discrimination of visual objects.

Adult↗

Ultrastructural evidences of growth inhibitory effects of a novel biocide, Akacid(plus), on an aflatoxigenic Aspergillus parasiticus.

The effects of Akacid(plus), a novel member of guanidine-based polymeric compounds recently introduced as a potent inhibitor of fungal growth and aflatoxin biosynthesis were studied on Aspergillus parasiticus by transmission electron microscopy (TEM). The toxigenic fungus was cultured on yeast extract-sucrose broth in presence of serial two-fold concentrations of Akacid(plus) (1.5-96 microL/50 mL medium) for 96 h at 28 degrees C with shaking. Mycelial samples exposed to fungistatic concentrations of compound (1.5-48 microL) were processed for TEM. Corresponding to the growth inhibition, TEM observations revealed morphological anomalies in fungal compartments. The results demonstrated that Akacid(plus) targets the plasma membrane of the hyphae by its breaking down at variable intervals with the formation of small membrane-bound vesicles inside the cytoplasm, while no obvious damage was observed on the cell wall. A marked depletion of cytoplasmic contents of hyphae accompanied with lysis and disruption of membranes of major organelles such as nuclei, mitochondria and endoplasmic reticulum indicates that in high fungistatic concentrations, Akacid(plus) passes not only through the cell wall but also through the plasma membrane and then interact with membranous structures of the cytoplasmic organelles. Ultrastructural changes of fungal compartments exposed to Akacid(plus) in relation to the fungal growth and aflatoxin biosynthesis are discussed.

Aflatoxins↗

Comparison of Tc-99m DTPA and Tc-99m MAG3 perfusion time-activity curves in patients with renal allograft dysfunction.

AIM: The perfusion time-activity curve on DTPA renal scintigraphy shows a peak and plateau pattern which is usually absent or less marked when using tubular agents such as MAG3. The exact mechanism that results in this difference between the two tracers is not well understood. A descending pattern on MAG3 has been proposed to be due to decreased extraction. In this study we compared the diagnostic utility of perfusion patterns obtained with DTPA and MAG3 among patients with renal allograft dysfunction. MATERIALS AND METHODS: This study included 48 patients with renal allograft dysfunction and 18 recipients with normal graft function. Every recipient had renal scintigraphy with Tc-99m MAG3 and Tc-99m DTPA 1 day apart. The second phase of the perfusion curve after the initial rise was classified as ascending, flat, or descending. In patients with a descending curve on DTPA study, we calculated the ratio of counts at peak perfusion to that at plateau (P:PL). Impaired perfusion was based on a deterioration of the peak-to-plateau pattern on DTPA and the presence of a flat-descending curve on MAG3. RESULTS: In patients with dysfunction, impaired perfusion was observed in 77% of DTPA and in 54% of MAG3 studies. A flat-descending curve on MAG3 was present in 44% of patients with normal graft function. By MAG3, 67% of acute rejection and 28% of chronic allograft nephropathy (CAN) cases showed deteriorated perfusion. The corresponding values for DTPA were 67% and 94%, respectively. A flat-ascending pattern on DTPA was more frequent in CAN than it was in acute rejection (33% and 17%, respectively). CONCLUSION: The sensitivity of DTPA perfusion pattern for diagnosing dysfunction was significantly greater than that for MAG3. Our results suggest that the major determinant of a curve pattern on DTPA or MAG3 study is the extraction relative to perfusion. Thus for patients with CAN, extraction is higher relative to perfusion, resulting in a lower P:PL ratio or an ascending curve on DTPA. Although the extraction of DTPA is less than that of MAG3, this level of extraction renders DTPA more sensitive to serial changes in renal function and pathophysiological mechanisms related to kidney function.

Acute Disease↗

Radionuclide evaluation of liver transplants.

Orthotopic liver transplantation is now an established technique for treating patients with various forms of end stage liver disease. The number of centers performing the procedure is increasing and, as the number of transplant recipients in the population increases, many institutions performing nuclear medicine studies will be confronted with requests to evaluate these patients. While a variety of radionuclides are proving useful in this evaluation, the 99mTc iminodiacetic acid (IDA) compounds, particularly 99mTc diisopropyl IDA (DISIDA), will probably account for the majority of radionuclide evaluations of these patients because they are well suited to monitor both structural and functional changes of the graft. The primary application of radionuclide studies is focused in the postoperative period, when problems with the vascular and biliary anastomoses, rejection, infections, and bile leaks all produce alterations in radionuclide hepatobiliary studies. Abnormalities such as rejection and infection produce primarily functional, rather than structural changes and are not easily differentiated based upon the kinetics of 99mTc-DISIDA extraction and excretion by the liver, serial imaging and correlation with clinical data is necessary in such situations. Quantitative analyses of kinetic 99mTc IDA (DISIDA) studies and quantitative approaches with other compounds such as 99mTc galactosyl-neoglycoalbumin (NGA) may permit better assessments of relatively subtle changes in liver function in the posttransplant period.

Bile Duct Diseases↗

Age and hormonal dependence of tonin levels in rat submandibular gland as determined by a new direct radioimmunoassay.

A simple and sensitive direct radioimmunoassay for tonin (EC.3.4.99.-) has been developed. This assay incorporates a modified and convenient poly(ethylene glycol) technique for separation of free from bound tonin. A rabbit antiserum in a final dilution of 1:160,000 was used and the purified tonin was labelled with 125I by using a lactoperoxidase method. It detects 20 pg of immunoreactive tonin per tube. Serial dilutions of rat submandibular gland extracts showed complete parallelism with tonin standard curves. No cross-reactivity with rat tissue kallikrein was seen. Intra- and inter-assay errors were 3.2 and 5.6%, respectively. Using this assay, immunoreactive tonin was detected in the rat submandibular gland as early as 3 weeks after birth (body wt. approximately 50-60 g). Tonin levels are shown to be dependent on age and sex with significantly higher levels in male than in female rats. Castration results in decrease of tonin levels and 17 alpha-methyltestosterone replacement reversed the level to higher than the sham-operated control rats. Cortisol treatment increased, but thyroxine or oestradiol had no effect, on tonin levels in the submandibular gland of castrated rats. This newly developed radioimmunoassay can now be used to measure low levels of tonin in various tissues and body fluids to address questions about its regulation and functional significance.

Aging↗

Cerebral atrophy following shaken impact syndrome and other non-accidental head injury (NAHI).

PURPOSE OF THE STUDY: To determine the frequency of cerebral atrophy and microcephaly in a group of children with sequential MRI brain scans after surviving a non-accidental head injury (n = 16). METHODS: Serial head circumference measurements (OFC) were extracted and plotted on standard growth charts for each child retrospectively to determine the frequency of secondary microcephaly. Cerebral atrophy was diagnosed and quantified by measurement of the ventricular/cortical ratio on coronal images of the sequential scans. RESULTS: Acquired microcephaly was found in 15 children (93.8%) over a median follow-up period of 67.93 weeks. There was a significant reduction in the median Z-score for the OFC at the most recent follow-up when compared with that at presentation (p < 0.001, Wilcoxon Signed Rank Test). Cerebral atrophy was found to be the cause of the microcephaly in eight of the 15 children and was evident as early as 9 days after presentation. CONCLUSION: A large proportion of the cohort (93.8%) develops acquired microcephaly after an inflicted head injury and cerebral atrophy is responsible in half of these cases.

Atrophy↗

Antigens in eggs and developmental stages of the sea urchin. I. Immunological and physicochemical properties.

A number of antigens in unfertilized eggs and embryos of the sea urchin Paracentrotus lividus were characterized with respect to both immunological and physicochemical properties. Experiments involved single diffusion in agar (Oudin technique) combined with mutual dilution, serial dilution, and heating of antigenic extracts, as well as immunoelectrophoresis with normal and heated extracts and agar electrophoresis followed by staining of the antigenic spots with protein specific dyes. The gradual transition in migration rates of bands of precipitates in Oudin tubes following mutual dilution of either extracts or antisera allowed the identification of 6 immunologically identical antigens in eggs and embryonic stages. Similarities with respect to diffusion coefficients, sensitivity to heat, electrophoretic mobility, and reaction to protein specific dyes indicated that the antigens in extracts of eggs and various developmental stages also had certain physicochemical properties in common. Such knowledge is of importance for an understanding of antigenic changes occurring during ontogenesis.

Animals↗

Foot and ear disease--the dermatophytid reaction in otology.

Chronic otitis external (COE) is occasionally refractory to treatment and may persist for years. In such cases, a dermatophytid (id) reaction from a fungal infection in a remote location should be suspected. Immunotherapy with dermatophyte (Trichophyton, Oidiomycetes, and Epidermophyton [T.O.E.]) extracts and dust mite, based on serial endpoint titration skin test results, as well as a yeast elimination diet, is the treatment of choice. Fourteen cases of id reaction are described. The primary fungal source was not always obvious, but immunotherapy and diet led to complete resolution of the COE in 8 cases (21.4%). Some case reports illustrate presentation, treatment, and outcome.

Dermatomycoses↗

An anomalous effect of allergen concentration on weal size elicited by skin testing for immediate hypersensitivity.

We report the finding of anomalous responses in the skin of atopic individuals when prick tested with serial dilutions of cocksfoot grass pollen extracts. Each pollen extract was standardized using RAST inhibition activity related to the WHO standard for IgE. 75% of the patients gave a larger weal area with an allergen concentration of 1:10(5) than with the next higher concentration, i.e. 1:10(4). Possible mechanisms whereby a larger skin weal is elicited with a lower concentration of allergen are discussed. This is not a rare finding and can be observed in patients undergoing routine skin testing in the clinic, even where extracts are diluted over a relatively narrow concentration range.

Allergens↗

Legionella oakridgensis: unusual new species isolated from cooling tower water.

We describe a new species of Legionella represented by 10 strains isolated from industrial cooling towers. Legionella oakridgensis differed genetically from the other seven species of Legionella in DNA hybridization studies and differed serologically in direct fluorescent-antibody tests. The new species, unlike all other species except L. jordanis, did not require added L-cysteine for growth in serial transfer on charcoal-yeast extract agar. L. oakridgensis, as well as three other species tested, required L-cysteine for primary isolation from animal tissues. L. oakridgensis was the only species of Legionella that failed to produce alkaline phosphatase at pH 8.5. In all other respects, it resembled other species of Legionella, including having a high content of branched-chain cellular fatty acids and being pathogenic for guinea pigs. These bacteria have not yet been associated with human disease, but they are potential causes of legionellosis.

Air Conditioning↗

Allostery of 3-deoxy-D-arabino-heptulosonate 7-phosphate synthetase in Clostridium: another conserved generic characteristic.

Enzymological studies were done to characterize the allosteric control of 3-deoxy-d-arabino-heptulosonate 7-phosphate (DAHP) synthetase in three species of Clostridium. Allosteric control was identified as feedback inhibition by phenylalanine and was qualitatively similar for the DAHP synthetases of C. butyricum, C. acetobutylicum, and C. tetanomorphum. Quantitative differences in the enzymology and kinetics of allosteric control distinguished C. tetanomorphum from C. butyricum and C. acetobutylicum. Crude extracts contained apparent proteolytic activity which could be fractionated from DAHP synthetase. The proteolytic activity was more labile than DAHP synthetase in extracts and was progressively inactivated by serial freeze-thaw treatments. Protease activity was at least partially inhibited by phenylmethylsulfonyl-fluoride. The method of comparative allostery of DAHP synthetase distinguishes the genera Bacillus and Clostridium, each having a strongly conserved pattern of regulation for DAHP synthetase. The data reinforce previous conclusions that allosteric control patterns governing the activity of DAHP synthetase are stable, reliable generic characteristics.

Aldehyde-Lyases↗

Nuclear magnetic resonance study of regional metabolism after forebrain ischemia in rats.

Proton nuclear magnetic resonance (NMR) spectroscopy of perchloric acid tissue extracts has been used to follow serial postischemic changes in the levels of metabolites in the hippocampus, cerebellum, frontal lobes, and parietal/occipital lobes in a rat model of short-duration (10 minutes) forebrain ischemia. Shortly (10 minutes, 1 hour) after the ischemic insult, the levels of the amino acids alanine and gamma-aminobutyric acid are elevated and that of glutamate is depressed in all regions except the cerebellum. The levels of these species return to control values by 24 hours postischemia. No changes are observed in the levels of aspartate or N-acetylaspartate. Greatly elevated levels of acetate 10 minutes postischemia, particularly in the hippocampus, may be due in part to metabolic degradation of fatty acids released due to membrane breakdown. Elevated levels of lactate persist for up to 7 days postischemia, suggesting that normal mitochondrial functioning is not fully restored following the ischemic insult.

Acetates↗

Altered alpha1-syntrophin expression in myofibers with Duchenne and Fukuyama muscular dystrophies.

Alpha1-syntrophin, a scaffolding adapter and modular protein, is a cytoplasmic component of the dystrophin glycoprotein complex. This study investigated immunohistochemically the expression of alpha1-syntrophin in Duchenne and Fukuyama muscular dystrophies (DMD and FCMD, respectively). Biopsied muscles of five DMD, five FCMD, five normal controls and five disease controls (three myotonic and two facioscapulohumeral dystrophies) were analyzed. Immunoblot analysis showed that anti-alpha1-syntrophin antibody had a decreased reaction in both DMD and FCMD muscle extracts. Biopsied muscle sections and their serial sections were immunostained with rabbit anti-alpha1-syntrophin and rabbit anti-muscle-specific beta-spectrin antibodies, respectively. Immunoreactive patterns of sarcolemma were classified into (i) a continuously positive immunostaining pattern, (ii) a partially positive immunostaining pattern, (iii) a negative immunostaining pattern and (iv) a faint but entire surface positive immunostaining pattern. The group mean percentages of alpha1-syntrophin and beta-spectrin immunonegative myofibers in the DMD group were 39.3% and 10.8%, respectively, while those in the FCMD group were 45.5% and 10.4%, respectively. These values were statistically significant compared with those of disease control and normal control muscles. Thus we found that dystrophin-deficient DMD muscles contained significant numbers of alpha1-syntrophin-positive fibers and significant numbers of alpha1-syntrophin-negative fibers were present in dystrophin-positive muscles of severe muscular dystrophy such as FCMD. Alpha-dystrobrevin immunoreactivity was tested in DMD muscles and appreciable amounts of alpha-dystrobrevin that binds to syntrophin were found in DMD muscle membranes.

Adolescent↗

Somatolactin, a novel pituitary protein: purification and plasma levels during reproductive maturation of coho salmon.

Somatolactin (SL), a newly discovered fish pituitary protein belonging to the GH/prolactin family, was isolated from coho salmon (Oncorhynchus kisutch). Antibodies were raised to purified coho SL, and a homologous radioimmunoassay was developed and validated. The assay was specific for SL as indicated by the absence of cross-reactivity with coho salmon GH, gonadotrophins I and II and less than 0.2% cross-reaction to prolactin. Serial dilutions of plasma and pituitary extracts from Oncorhynchus species including coho salmon, chinook salmon and rainbow trout were parallel to the coho salmon SL standard curve. Displacement curves for dilutions of Atlantic salmon (Salmo salar) plasma, but not pituitary extract were parallel to the standards. Plasma levels of SL were measured in coho salmon throughout the final year of reproductive maturation. During the period of gonadal growth, plasma SL levels increased and were highly correlated to oestradiol levels in females and 11-ketotestosterone levels in males. Peak levels of SL were observed at the time of final maturation and spawning in both sexes. It is hypothesized that SL may regulate some physiological aspect of reproduction.

Amino Acid Sequence↗

Induction of heat-shock proteins HSP73 and HSP90 in rat kidneys after ischemia.

We examined rat kidneys for serial expressions of two major heat-shock proteins (HSPs), HSP73 and HSP90, after 60 min of unilateral renal ischemia up to day 28. Immunohistochemical studies showed that HSP73 and HSP90 were rapidly induced in the cytoplasm of injured epithelial cells of the S3 segment of proximal tubules and were again induced in the cytoplasm of regenerative cells in this segment from day 3. In epithelial cells of the Henle's loops, HSP90 was also induced in the cytoplasm of both injured and regenerative cells, but HSP73 was not induced in this portion. Furthermore, a transient accumulation of HSP73 into the nucleus was observed in epithelial cells of papillary collecting ducts shortly after ischemia. Serial immunoblot analysis of isotonic buffer extractable fractions from ischemic kidneys revealed the induction of both HSP73 and HSP90 in the degenerative and regenerative phases: the maximal inductions in the two phases were at 3-6 and on days 5-7, respectively. These results demonstrate that HSP73 and HSP90 are induced in injured tubular epithelial cells with a regional heterogeneity during the degenerative and regenerative phases after renal ischemia and suggest that these HSPs are involved in the process of postischemic cellular recovery.

Animals↗

[The meanings of the papaverine test].

Intracavernous administration of papaverine is now commonly employed for diagnosis and therapy of impotence. To assess the pharmacokinetics of papaverine, we recorded its concentration in peripheral blood and also in cavernous blood after intravenous and intracavernous injection of 40 mg of papaverine. Peripheral blood was sampled serially after injection. Plasma was immediately extracted and then kept at at -40 degrees C until analysis. High pressure liquid chromatography was used to record the concentration of papaverine. The maximum serum concentration of papaverine measured after intracavernous injection was 7.7 ng/ml, which was considerably lower than the average serum concentration of 24.0 ng/ml after intravenous injection. Peak serum concentration was reached 1 min after intravenous injection and 10 min after intracavernous injection. It is clear that the corpus cavernosum constitutes a separate pharmacokinetic compartment. Therefore there was no significant difference between the papaverine concentration in peripheral blood of patients who showed full erection after intracavernous injection and that of patients who did not achieve erection. The concentration of papaverine in the intracavernous blood of a fully erected penis was only about 1 microgram/ml after 20 min. This concentration is similar to that in cavernous blood of those who showed excessively persistent erection. Our results imply that papaverine administered into the cavernous space relaxes smooth muscle, and is then washed out to general circulation, and the concentration in the cavernous space reaches a low level of about 1 microgram/ml. The low concentration level is maintained for several hours during erection. Therefore, we presume that papaverine acts on both the inflow system and smooth muscle of cavernous tissue in the phase of producing erections.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Improvement of myocardial and other vital organ functions and metabolism with a simple method of pulsatile flow (IABP) during clinical cardiopulmonary bypass.

A simple, safe, and effective method of producing pulsatile flow during cardiopulmonary bypass (CPB) with intra-aortic balloon pumping (IABP) was used in 56 patients. No complications were associated with IABP. Myocardial metabolic studies, including coronary sinus lactates, mycoardial venous-arterial lactate differences, myocardial lactate extraction, and "excess lactate" were determined serially during the first hour of CPB. Changes in myocardial metabolism were statistically less abnormal in pulsatile flow (PF) patients when contrasted with a comparable group of nonpulsatile flow (NPF) patients. The changes were probably myocardial in origin since alterations in arterial lactates and lactate/pyruvate ratios were similar in both groups. In a comparable group of coronary bypass NPF patients, the percentage of left ventricular ejection fractions fell during the immediate postoperative period, whereas it rose in the PF group. Over-all body tissue injury (lactic dehydrogenase) and probably hepatocellular injury (serum glutamic oxalacetic transaminase) were less apparent in the PF patients. Postoperative low-cardiac-output syndrome did not occur in the PF patients and supportive drugs and diuretics were not needed. PF does not produce excessive hemolysis. This procedure may improve mortality rates by improving myocardial and other vital organ perfusion and by sustaining their function during weaning from CPB. This technique may prove superior to other forms of PF and is indicated in patients with severe left ventricular or other vital organ dysfunction and/or prolonged CPB.

Aspartate Aminotransferases↗