Cells and viruses with mutations affecting viral entry are selected during persistent infections of L cells with mammalian reoviruses

Previous studies demonstrated that both cellular and viral mutants are selected during maintenance of persistent infections established in murine L cells with high-passage stocks of mammalian reoviruses. In particular, when one culture was cured of persistent infection, the resulting cells were found to support the growth of viruses isolated from persistently infected cultures (termed PI viruses here) better than that of wild-type (wt) viruses (R. Ahmed, W. M. Canning, R. S. Kauffman, A. H. Sharpe, J. V. Hallum, and B. N. Fields, Cell 25:325-332, 1981). To address the nature of cellular and viral mutations selected during maintenance of persistent reovirus infections, we established independent, persistently infected cultures with L cells and high-passage stocks of wt reovirus. These cultures served as sources of new PI viruses and cured cells for study. We found that although wt viruses grew poorly in cured cells when infection was initiated with intact virions, they grew well in cured cells when infection was initiated with infectious subvirion particles generated from virions by in vitro treatment with chymotrypsin. This finding indicates that the block to growth of wt viruses in cured cells involves an early step that is unique to infection by virions, such as proteolytic processing in an endocytic compartment. We also found that PI viruses grew better than wt viruses in L cells treated with ammonium chloride, a weak base that inhibits the pH decrease in endosomes and lysosomes. Because ammonium chloride blocks an early step in infection by intact virions, probably the proteolytic processing of viral outer capsid proteins by acid-dependent cellular proteases in late endosomes or lysosomes, this finding indicates that PI viruses differ from wt viruses with respect to viral entry into cells. Therefore, these results indicate that both cells and viruses evolve mutations that affect one or more early steps in the viral growth cycle during maintenance of L-cell cultures persistently infected with reoviruses.     

Psychological differentiation and psychotherapy

Patient's level of psychological differentiation was studied in relation to patients' and therapists' evaluations of the initial psychotherapy session. The evaluations assessed two broad dimensions of the interaction which generally have been considered important for psychotherapeutic success and which have been found to be related to patients' psychological differentiation: namely, patients' and therapists' satisfaction with the amount of structure, and therapists' impressions of patients' appropriateness for therapy. Significant correlations were obtained between patients' psychological differentiation and both of these dimensions. However, two control variables, socioeconomic status and alcohol use, were also found to be related to these dimensions. When the effects of these variables were partialed out, the relationships with therapists' impressions of appropriateness disappeared, but the relationships with patients' and therapists' satisfaction with the amount of structure remained significant. The relationship of these findings to other studies of psychological differentiation and psychotherapy is discussed. Finally, the contribution of the present results to the choice of the most appropriate measure of psychological differentiation is noted.     

The polyploidization characteristics of the hepatocytes of the mouse-like hamster Calomyscus mystax

A cytophotometric measurement of DNA content in hepatocytes of maturing mouse-like hamsters was made. Cells belonging to ordinary mammalian ploidy classes 2c, 2c x 2, 4c, and 4c x 2 made about 90% of the hepatocyte population. The share of binucleated cells wa high (about 80%), the majority of these cells being 2c X 2 hepatocytes. Binucleated cells with tetraploid and diploid nuclei occur in almost every animal. An average hepatocyte ploidy level in mouse-like hamster is 4.6c. The main peculiarity of parenchymal liver cell populations is that up 5% of hepatocytes contain 3--11 nuclei of different ploidy classes. Multinucleated cells increase in number from 1.5% to 4% within the period from one year (the age of maturation) to two years. Later on their percentage does not change. It is found that in binucleated and multinucleated hepatocytes DNA synthesis can proceed asynchronously. Asynchrony in DNA synthesis elevates as the number of nuclei increases. Among the 2c x 2 and 2c x 3 cells an uneven distribution of 3H-thymidine label can occur, respectively, in 5 and in 50% cases, whereas all the cells with more than 3 nuclei display an uneven an uneven 3H-thymidin label distribution. The formation of multinucleated cells is supposed to be associated with asynchrony in DNA-synthesis in binucleated cells and with the restitution of mitosis.     

Ovariectomy-induced bone loss and the hematopoietic system

To investigate the relationship of the hematopoietic system to the loss of bone due to ovarian hormone deficiency, we examined the effects of ovariectomy and estrogen administration on the thymus, spleen and the bone marrow, and on the proliferation of marrow progenitors of osteoclasts. We also assessed the effects of daily administration of interleukin-1 receptor antagonist (IL-1ra) on bone loss due to ovarian hormone deficiency. Ovariectomy resulted in decreased cancellous bone volume, increased trabecular osteoblast and osteoclast numbers, and increased serum alkaline phosphatase levels that were prevented by 17 beta-estradiol treatment. Thymus weight, spleen weight, thymus and spleen lymphocytes, and bone marrow monocytes and lymphocytes also increased significantly following ovariectomy, and the increases were suppressed by 17 beta-estradiol. Ovariectomy, in addition, caused a 4-fold increase in the number of tartrate resistant acid phosphatase (TRAP)-positive multinucleated cells formed in cultures of marrow cells and the increase was partially inhibited by 17 beta-estradiol. IL-1ra administration did not prevent the bone loss due to ovariectomy. Our findings indicate that ovariectomy-induced bone loss in the rat is accompanied by marked changes in the hematopoietic system, and that these changes are modulated by estrogen administration. In spite of the negative finding with IL-1ra, the nature of the involvement of the hematopoietic system in the pathogenesis of bone loss due to ovarian hormone deficiency merits continued exploration.     

Alveolar bone growth in response to endosteal implants in two patients with ectodermal dysplasia

Osteitis condensans of the clavicle is a rare condition characterized by pain in the shoulder and often limitation of motion of the shoulder. The medical history and results of the physical examination, laboratory data, and radiographic studies (including computed tomography and magnetic resonance imaging), often establish the diagnosis. Patients who have slight or no pain usually require no treatment. Varying results have been reported for many different methods of treatment, including surgical excision, chemotherapy, antibiotics, nonsteroidal anti-inflammatory medications, radiation, local corticosteroid injection, and physical therapy. A typical case report and the differential diagnosis for condensing osteitis of the clavicle are presented.     

Chronic dosing with aminoguanidine and novel advanced glycosylation end product-formation inhibitors ameliorates cross-linking of tail tendon collagen in STZ-induced diabetic rats

Solubility of tail tendon collagen from normal, streptozotocin-induced diabetic Lewis rats, and diabetic animals treated with aminoguanidine and two novel advanced glycosylation end products (AGE)-formation inhibitors was investigated by limited pepsin digestion under acidic conditions. Assays were conducted using tail tendon collagen from Lewis rats obtained from two different vendors, Harlan and Charles River Laboratories. Collagen solubility was assessed by following the kinetics of pepsin digestion. The data revealed that the rate of digestion for diabetic animals is markedly slow relative to that of normals. More strikingly, the kinetics of the diabetic animals showed the feature of a lag in digestion regardless of the animal source. Experiments designed to optimize the difference in solubility between normal and diabetic animals demonstrated that Charles River animals exhibit a greater window of solubility than the Harlan animals. More importantly, a pronounced effect of aminoguanidine, an AGE-formation inhibitor, was observed in Charles River animals, but not in the Harlan animals, presumably because of the larger window of solubility between the normal and the diabetic animals in the former. These data indicated that the Charles River Lewis rats are an animal model that demonstrates greater efficacy in this assay. Analysis of in vivo screens designed to test efficacy of aminoguanidine and two novel AGE-formation inhibitors, ALT 462 and ALT 486, demonstrated that monitoring an in vivo dose response is highly dependent on the enzyme concentration as well as the time of digestion, and that 1.5 h of digestion and 10 microg/ml pepsin (5 pg pepsin/mg collagen) appeared optimal. Under these conditions, a 29% normalization of solubility was observed with aminoguanidine at 100 mg/kg body wt, whereas a similar normalization was observed at 10 mg/kg body wt for both ALT 462 and ALT 486. Thus, on a molar basis, ALT 462 and ALT 486 are at least 20 times more potent than aminoguanidine. This is the first demonstration of dose-dependent efficacy for AGE-formation inhibitors in animal models, and as such, this assay provides a method with which to assess the in vivo efficacy of other such inhibitors.     

Acute alcohol exposure markedly influences male fertility and fetal outcome in the male rat

Although it is recognized that drugs ingested by pregnant females produce marked cognitive and physiological deficits in their offspring, the possibility that paternal exposure to drugs prior to mating may have adverse effects on fertility and fetal outcome has not received much attention. The purpose of the present studies was to examine whether a single, acute exposure to alcohol influences the subsequent ability of adult male rats to mate and produce healthy and viable litters. Our results showed that a relatively large dose of alcohol 24 hours prior to breeding had little effect on the mating behavior of male rats, but there were markedly fewer pregnancies in females mated with alcohol-exposed male rats than in controls. Of equal importance, we found that, even when conception occurred and live births were produced, there were striking differences in fetal outcome. Alcohol-treated males sired many fewer pups than control males and there was a markedly enhanced mortality rate in their offspring. Collectively, these data suggest that acute paternal alcohol administration 24 hours prior to breeding does not affect mating behavior, but results in a greatly diminished fertility rate and fewer and less viable offspring. These studies suggest that paternal alcohol use may be as important as maternal alcohol abuse as a negative variable in pregnancy and fetal outcome.     

A quantitative evaluation of the glycogen content of the hepatocytes from different lobular ares of the normal human liver and in chronic hepatitides of different etiologies

Investigation of glycogen function in hepatocytes of different liver lobule zones is particularly important in understanding glycogen metabolism in humans and animals in norm and pathology. The present study was done to investigate glycogen contents in hepatocytes of different lobule zones of human liver in norm, and in patients with chronic hepatitis of viral or alcohol etiology. Quantitative analysis of glycogen content in hepatocytes of portal and central lobule zones was conducted on slices of human liver (the material of series live punctional biopsies) stained using a quantitative variant of PAS-reaction (Kudryavtseva et al., 1970, 1974). The measurements were done by image analyzer , which allows to make jointly cytophotometric analysis of substance in cells and definition of cell localization in tissue. The results showed clear differences of glycogen contents in different lobule zones in normal liver and in liver during chronic viral and alcohol hepatitis. Glycogen contents in hepatocytes of portal lobule zone were significantly higher than in the central lobule zone in patients with chronic viral hepatitis. Opposite data were obtained in patients with chronic alcohol hepatitis. Significantly higher glycogen contents were found in hepatocytes of the central liver lobule zone. Possible mechanisms of such a phenomenon are discussed . Thus, if glycogen contents in hepatocytes may be taken as an indicator of liver chronic damage degree (as has been shown elsewhere: Kudryavtseva, 1987; Kudryavtseva et al., 1988) the pattern of distribution of hepatocytes with different glycogen content in the liver lobule can be used as an indicator of etiology of chronic hepatitis. The obtained data seem to be important and actual, particularly for diagnostic of subclinical and symptomless forms of these diseases. Further investigation is required to find out reasons and mechanisms of this phenomenon.     

Three new ellagic acid derivatives from the bark of Eschweilera coriacea from the Suriname rainforest

Bioassay-guided fractionation of Eschweilera coriacea collected in the lowland wet forest of Suriname yielded the new but only weakly active ellagic acid derivative eschweilenol A (1) and the two new but inactive ellagic acid derivatives eschweilenol B (2) and eschweilenol C (3). The four known compounds, sucrose, ellagic acid, 3-O-galloylepigallocatechin, and epigallocatechin, were also isolated. The structures of the three new compounds were determined by spectrometric methods, primarily from the HMQC, HMBC, NOESY, and ROESY NMR techniques, and chemical methods, including methylation and triethylsilylation. The location of a hydroxyl group in one ellagic acid derivative was determined by a new technique involving an NOE correlation of the protons of a triethylsilyl derivative with a proton on a neighboring aromatic ring.