Absence of interferons-alpha and -gamma in renal lesions of systemic lupus erythematosus and membranous glomerulonephritis

Frozen kidney biopsy sections from nine patients with systemic lupus erythematosus (SLE) as well as many other renal diseases, including IgA nephropathy, membranous nephritis, and minimal change nephrotic syndrome, were negative for interferons -alpha and -gamma by immunofluorescence. Lupus patients studied included several subjects with marked serum elevations of interferon activity as well as others with low or negative serum interferon levels. Isolated glomerular eluates prepared from normal and SLE kidneys showed no functional interferon activity by virus plaque inhibition assay. Components of normal as well as SLE serum showed no direct binding to interferon -alpha or -gamma by ELISA assays.     

Clonidine suppression and its adrenoreceptor mediation in schedule-induced polydipsia

Rats were trained in a fixed-interval, one-minute (FI 1 min) food reinforcement schedule for 1 hour daily at reduced body weight until their lever presses, licks and water intake all became stabilized for 6 days. Two experiments were performed to examine the function of sympathetic activity in schedule-induced polydipsia. In experiment 1, intracerebroventricular injection of clonidine (0.75-37.5 nmol) produced a dose-related suppression of schedule-induced drinking and licking and schedule-dependent lever pressing; these effects were later attenuated by yohimbine (5 nmol) pretreatment. Prazosin (10 nmol) also decreased clonidine-induced suppression of lever pressing, whereas neither prazosin (10 nmol) nor naloxone (10 nmol) caused any alteration in the suppression effects of clonidine on drinking and licking. None of these antagonists alone changed an individual rat's preestablished behavioral baselines. In experiment 2, the endogenous catecholamine levels, were determined in frontal cortex, hypothalamus, brainstem, dorsal obex area and adrenal glands. During the SIP situation, both the epinephrine level in adrenal glands and the norepinephrine level in hypothalamus were elevated.     

Biochemical characterization of human Thy-1

The human Thy-1 homologue (p25) was characterized biochemically for amino acid composition, sequence and carbohydrate content. Two other forms of the human Thy-1 molecule were detected and partially characterized. A 40,000 mol.wt. molecule (p40) is the dimer of p25 and its formation is increased by the presence of sodium dodecyl sulphate (SDS). The second form of 16,000 mol.wt. (p16) appears to be a cryptic or breakdown form of p25. Comparison of the amino acid compositions of p25, p40 and p16 isolated from MOLT-3 cells, with that deduced from the nucleotide sequence of the gene coding for part of the putative T cell antigen receptor, also from MOLT-3 cells, shows that the Thy-1 homologue is distinct from, but evolutionary related to, one of the putative T cell antigen receptor polypeptide chains.     

Topography and behavior of Sertoli cells in sparse culture during the transitional remodeling phase

We report observations on the behavior of Sertoli cells in sparse culture during the period from the time of plating to the time of initial confluence (the transitional remodeling phase). Changes in shape, structure, and polarity of cells, as well as changes in migration patterns and cell-cell association patterns, have been followed during the transitional remodeling phase with the aid of topographical markers. These markers are based upon differences between ultrastructural features of the basolateral and apicolateral surfaces. The basolateral surface is characterized by plasmalemmal blebs, whereas the apicolateral surface is characterized by filopodial extensions. Structural differences observed in situ remain evident in Sertoli cells isolated by sequential enzymatic treatments that are described. Another marker is provided by laminin-binding sites, which are detected exclusively on the blebbed, basolateral surfaces of freshly prepared Sertoli cell aggregates. The orientation described is sustained during the initial radial migration of Sertoli cells explanted on uncoated glass coverslips. Under these conditions, blebs are detected only on the dorsal surfaces, and filopodial extensions are evident only on the ventral surfaces. In contrast, Sertoli cells sparsely plated on a reconstituted basement membrane (air-dried Matrigel) migrate rapidly, display an extraordinary capacity to form elaborate cytoplasmic extensions for cell-cell and cell-substratum contacts, and readily retract blebs and filopodial extensions. These cells do not form mosaic borders, whereas cells plated on uncoated glass do form a monolayer with mosaic-like borders. Cells sparsely seeded on gelated Matrigel migrate preferentially at gaps between adjacent cell explants, and develop a compact cell-cell association pattern. These cells display few, if any, cytoplasmic extensions. We compare the behavior of Sertoli cells sparsely plated on Matrigel with the behavior of Sertoli cells in situ during different stages of development.     

Detection and characterization of diarrheagenic Escherichia coli from young children in Hanoi, Vietnam

Diarrhea continues to be one of the most common causes of morbidity and mortality among infants and children in developing countries. Escherichia coli is an emerging agent among pathogens that cause diarrhea. The development of a highly applicable technique for the detection of different categories of diarrheagenic E. coli is important. We have used multiplex PCR by combining eight primer pairs specific for enteroaggregative E. coli (EAEC), enteroinvasive E. coli (EIEC), enterohemorrhagic E. coli, enteropathogenic E. coli (EPEC), and enterotoxigenic E. coli (ETEC). This facilitates the identification of five different categories of diarrheagenic E. coli from stool samples in a single reaction simultaneously. The prevalences of diarrheagenic E. coli were 22.5 and 12% in the diarrhea group and the control group, respectively. Among 587 fecal samples from Vietnamese children under 5 years of age with diarrhea, this technique identified 132 diarrheagenic E. coli strains. This included 68 samples (11.6%) with EAEC, 12 samples (2.0%) with EIEC, 39 samples (6.6%) with EPEC, and 13 samples (2.2%) with ETEC. Among the 249 age-matched controls, 30 samples were positive for diarrheagenic E. coli. The distribution was 18 samples (7.2%) with EAEC, 11 samples (4.4%) with EPEC, and 1 sample (0.4%) with ETEC.     

Evaluation of ultra-thin poly(epsilon-caprolactone) films for tissue-engineered skin

Various natural and synthetic polymeric materials have been used as scaffold matrices for tissue-engineered skin. However, the commercially available skin replacement products pose problems of poor mechanical properties and immunological rejection. We have thus developed a film of 5 microm thickness, via biaxial stretching of poly(epsilon-caprolactone) (PCL), as a potential matrix for living skin replacements. The aim of this study was to evaluate the feasibility of using biaxially stretched PCL films as matrices for culturing human dermal fibroblasts. For this purpose, we cultured human dermal fibroblasts for 7 days on the films. Glass cover slips and polyurethane (PU) sheets were used as controls. The data from phase contrast light, confocal laser, and scanning electron microscopy suggested that biaxially stretched PCL films support the attachment and proliferation of human dermal fibroblasts. Thymidine-labeling results showed quantitatively that cell proliferation on the PCL films was superior to that on the PU samples. These results indicated that biaxially stretched PCL films supported the growth of human dermal fibroblasts and might have potential to be applied in tissue engineering a dermal equivalent or skin graft.     

Effect of hypothermia on the intestinal absorption of uracil and L-dopa in the rat

The in situ rat gut technique was used to explore the effects of hypothermia on the intestinal absorption of L-dopa and uracil. A hypothermic state was induced when male Sprague-Dawley rats, weighing between 300 and 370 g, were exposed to an atmosphere of helox (helium:oxygen, 80:20) at 0-4 degrees C. After 4 to 5 h, the rectal temperatures were decreased from 37 to 20 degrees C. The rewarming process for hypothermic animals undergoing anesthesia appears to be prolonged. The animals were prepared for surgery using ether as anesthetic after a rectal temperature of 20 degrees C was attained. Hypothermia showed a significant influence on decreasing L-dopa and uracil disappearances from the intestinal lumen. About 40 percent reduction of the rates of disappearance was observed with a 10 degrees C reduction of the rectal temperature. Additionally, a rapid drop of the rate of drug disappearance was observed in the beginning stage of rectal temperature decrease (31-36 degrees C) as well as in the hypothermic state with rectal temperatures < 26 degrees C. There appears to be a thermal stable region for absorption between 26 and 30 degrees C. Water efflux was studied in both normothermic and hypothermic animals. Normothermic rats showed greater average cumulative water efflux over a period of 30 min (71 and 61% for L-dopa and uracil, respectively) in comparison with that of hypothermic rats (34 and 41% for L-dopa and uracil, respectively). The cold-treated animals showed decreased rates of disappearance associated with the decreased water efflux. Therefore, the reduction of the rates of drug disappearance from the intestinal lumen caused by hypothermia may be partially related to the decrease of water efflux during hypothermia.     

Variations in Safe Sleep Practices and Beliefs: Knowledge is not Enough

Maternal and Child Health Journal - Sleep-related infant deaths in the District of Columbia (DC) varies, with rates in certain geographical areas three times higher than DC and seven times higher...