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Biomedical subjects

E L Parr

Publications and source records attributed to E L Parr.

At least 73 records · Page 4Linked to original sources
PubMed1985

Immunohistochemical localization of immunoglobulins A, G and M in the mouse female genital tract.

The localization of immunoglobulins A, G and M (IgA, IgG, IgM) in the mouse genital tract was studied by immunoperoxidase techniques at oestrus, on the day of mating and at the time of implantation. In the horns and body of the uterus, IgA and IgG were located in plasma cells in the endometrium surrounding uterine glands and in the gland lumina. The numbers of these plasma cells increased markedly between Day 1 and Days 4 and 5 of pregnancy and the ratio of plasma cells containing IgA and IgG was about 3 or 4 to 1 at all stages. Area measurements indicated that the increased number of plasmacytes was not due to an increase in the amount of endometrial, myometrial or glandular tissues. Plasma cells were not detected in the cervix and vaginal fornix at oestrus and Day 1, but a few were present on Day 5. In the oviduct, plasma cells containing IgA and IgG were present only in the preampulla and both immunoglobulins were present in the extracellular space of the lamina propria only in this region. No IgM was detected in any part of the reproductive tract at any of the times studied. Uteri on Day 1 of pregnancy contained bacteria of several kinds, some of which were aggregated and coated with IgA. This suggests that the uterine lumen at this time may contain specific anti-bacterial IgA antibodies. Our observations indicate that the horns and body of the uterus and the preampulla of the oviduct are major sites of a local immune system in the female mouse genital tract.

Animals↗
PubMed1982

Quantitation of H-2 antigen expression on hepatocytes and macrophages: evidence for an influence by strain background.

The surface concentration of H-2 complex antigens was measured by a quantitative immunoferritin labelling technique on hepatocytes and macrophages from five mouse strains with three haplotypes. The concentration of H-2 molecules was similar on macrophages from three B10 congenic strains, and the same similarity was observed on hepatocytes from the three strains. With both hepatocytes and macrophages, however, the surface concentration of H-2d molecules on BALB/c cells was about twice that on B10.D2 cells, and that of H-2k molecules on C3H/HeJ cells was about twice what we observed on B10.BR/SgSn cells. These measurements suggest a regulation of the surface concentration of H-2 complex antigens by a locus outside the MHC.

Animals↗
PubMed1982

Relationship of apical domes in the rabbit uterine epithelium during the peri-implantation period to endocytosis, apocrine secretion and fixation.

The luminal surfaces of non-ciliated uterine epithelial cells of 17 rabbits on Days 4--6 of pregnancy were studied histologically with light microscopy, transmission and scanning electron microscopy. The luminal surfaces of most epithelial cells exhibited short microvilli and did not project into the uterine lumen. However, the surfaces of some cells showed fewer microvilli and bulged out into the uterine lumen, giving the cells a dome-like appearance. The domes appeared most frequently on Day 6 of pregnancy and contained a few ribosomes, mitochondria, and membranous elements; large vacuoles and granules were absent. The domes were not involved in endocytosis. Ferritin introduced into the uterine lumen was incorporated into the cells by coated micropinocytotic invaginations at the base of the microvilli, rather than by any activity of the domes. There was also no indication that the domes pinched off to produce an apocrine secretion. The size and frequency of domes were, however, clearly related to the fixation procedure. Epithelial cells from uteri fixed by vascular perfusion showed fewer and less prominent domes, while cells from uteri fixed by immersion displayed a larger number of domes that projected further into the uterine lumen. The domes in the rabbit epithelium therefore differ structurally and functionally from the apical projections (pinopods) that occur in the uterine epithelium of the rat and mouse during the peri-implantation period.

Animals↗
PubMed1982

The surface concentration of H-2 antigens on mouse pancreatic beta-cells and islet cell transplantation.

Measurement of the concentration of H-2 complex antigens in the surface membrane of mouse pancreatic beta-cells by a quantitative immunoferritin-labeling technique revealed that the antigens were present in very small amounts on the beta-cells of five strains. A comparison of the labeling densities in the five strains suggested that beta-cells from C57BL/10Sn congenic strains have about half the H-2 antigen density of BALB/c and C3H/HeJ cells. In C57BL/10Sn mice the antigen density on beta-cells was slightly greater than that on erythrocytes, about 20% of that on thymocytes, and about 2.5% of that present on peritoneal macrophages. Intraperitoneal allografts of c57BL/10Sn islets were uniformly rejected by B10.BR/SgSn diabetic recipients only when the islets were accompanied by 10(7) peritoneal lymphoid cells. When transplanted without peritoneal cells, C57BL/10Sn islets were only marginally rejectable. In a group of nine such allografts, three diabetic recipients were permanently cured and three others showed rejection times of about 30 days. Sensitization of the three mice showing permanent cures, using 10(7) allogeneic peritoneal cells at about 40 days after the transplant, did not cause rejection of the allografts. Isogeneic transplantation of cell suspensions from dissociated islets of Langerhans was markedly less effective in controlling diabetes than intact islets, and dissociation did not obviously improve the rate of allograft survival. However, 5/19 diabetic mice receiving allografts of dissociated islet cells showed long-term reversals of diabetes that were unaffected by administration of 10(7) peritoneal cells at about 100 days after the transplant. Recipient mice whose diabetes was reversed by islet allografts and unaffected by specific sensitization had pancreatic insulin concentrations characteristic of diabetic mice. Our reversals of diabetes with untreated islet allografts may be due to the cleanliness of islet preparations obtained with a modified isolation technique, and to the very low density of H-2 complex antigens on C57BL/10Sn beta-cells.

Animals↗
PubMed1980

Epithelium of mouse yolk sac placenta lacks H-2 complex alloantigens.

The only fetal cell membrane exposed to the mother in the mouse yolk sac placenta is the apical membrane of the endodermal epithelial cells. In yolk sac preparations in vitro, this apical membrane was exposed to reagents or cells in the incubation medium. By using several techniques we were not able to detect fetal major histocompatibility complex (MHC) antigens in this membrane. Immunoferritin labeling with and without prefixation and after neurominidase and trypsin digestion indicated that the apical membrane could contain no more than approximately 1% of the H-2 complex antigens that were present on peritoneal macrophages. Incubation of yolk sac preparations in anti-H-2 complex antiserum and complement had no cytotoxic effect on the endodermal epithelium, nor did incubation in an excess of alloreactive lymphocytes. Dissociated preparations of prefixed yolk sac contained endodermal epithelial cells and vascular endothelial cells whose entire surface membranes were exposed to the medium. H-2-complex antigens were not detected by immunoferritin labeling in either the apical or the laterobasal membrane of the yolk sac endoderm, but they were present in low density on the vascular endothelium. Also, incubation of unfixed, dissociated cells in anti-H-2-complex serum and complement had no detectable cytotoxic effect on endodermal epithelial cells. These observations indicate that H-2 antigens are sparse or absent in both the apical and laterobasal membranes of endodermal epithelial cells. The deficiency of MHC antigens in the apical membrane may account for the failure of sensitized females to reject the yolk sac, whereas the composition of the laterobasal membrane is probably less important to maternal-fetal relations. The present observations are consistent with labeling studies of adult-lining epithelial cells, which indicate that self-marker MHC molecules are absent from the apical membranes oriented toward the outside world and variably expressed in the laterobasal self-side membranes. It is suggested that the corresponding exclusion of fetal self-marker molecules from the apical membranes of some kinds of placental epithelia would deprive the mother of target sites for an alloimmune reaction at the maternal-fetal interface.

Animals↗
PubMed1980

Cellular changes in cultured mouse thyroid glands and islets of Langerhans.

Islets of Langerhans cultured 7 days in vitro no longer contained any capillary endothelial cells, but their endocrine cells remained ultrastructurally normal up to 14 days. Vascular endothelial cells were also lost from cultured thyroid lobes, but more slowly. Thyroid endothelium was readily identified after 7 days of culture, although many cells appeared to be degenerating, and a few degenerating endothelial cells were still present after 14 days in culture. Erythrocytes and leukocytes in the lumina of thyroid vessels were observed to degenerate at about the same rate as the endothelial cells, while those in islet capillary lumina were largely washed out during isolation of the islets. Thyroid lymphatic endothelium and the numerous adipose cells present in this tissue also degenerated during the culture period. Follicle epithelial cells remained viable throughout the culture period, but the number of colloid droplets and endocytic vesicles they contained was markedly, decreased. Thyroid fibroblasts remained viable and appeared to enlarge and accumulate dense granules during culture. These cells were a prominent feature of thyroid lobes after 14 days of culture. Parathyroid tissue associated with the thyroid lobes showed viable endocrine cells but a loss of vascular endothelium after 14 days in culture. The loss of blood leukocytes and vascular endothelial cells in probably the major factor in the altered behavior of thyroid and islet allografts after culture in vitro.

Animals↗
PubMed1980

H-2 complex and Ia antigens on cells dissociated from mouse thyroid glands and islets of Langerhans.

Mouse thyroid tissue was dissociated with collagenase, fixed in periodate-lysine-paraformaldehyde (PLP), and further dissociated with EDTA and trypsin to yield cell suspensions containing mainly follicle epithelial cells and vascular endothelial cells. H-2 complex antigens were detected on the vascular endothelial cells at about the same high density as on peritoneal macrophages, and at a lower concentration on the laterobasal membranes of follicle epithelial cells. Neither of these cell types expressed detectable Ia antigens, but a minor cell type was presented that showed dense expression of Ia antigens. This cell type was probably a passenger leukocyte. It showed ultrastructural characteristics closely resembling those of spleen dendritic cells, which are known to express Ia antigens and to be potent stimulator cells in mixed lymphocyte culture. Dissociation of thyroid glands that had been cultured in vitro for 14 days yielded only follicle epithelium, and these cells showed the same labeling density of H-2 complex antigens as on uncultured cells. Dissociation of islets of Langerhans yielded capillary endothelial cells and beta cells, neither of which expressed detectable Ia antigens. The labeling results are discussed in relation to the cellular changes that occur during culture in vitro and the altered behavior of cultured allografts.

Animals↗
PubMed1979

The absence of H-2 antigens from mouse pancreatic beta-cells demonstrated by immunoferritin labeling.

Islets of Langerhans were isolated from mouse pancreases and fixed in periodatelysine-paraformaldehyde. The fixed islets were then dissociated with trypsin and EDTA to yield cell suspensions that contained mainly four cell types; beta-cells, capillary endothelial cells, acinar cells, and pancreatic duct epithelial cells. The nonislet cells were probably associated wtih the surface of the isolated islets. The H-2 antigens of the dissociated pancreatic cells were labeled with an immunoferritin technique. Pancreatic duct epithelial cells showed specific ferritin labeling on their lateral cell membranes but not on apical microvillus membranes. Acinar cells were also labeled on lateral membranes, and the capillary endothelial cells were labeled on both the luminal and albuminal aspects of their surface membranes. In contrast, pancreatic beta-cells were unlabeled. The number of ferritin molecules per unit length of beta-cell membrane was essentially the same on cells from the antigenic strain and the congeneic control strain, and was about 200-fold less than on the labeled pancreatic duct epithelial cell lateral membranes. Pancreatic beta-cells are therefore one of six known epithelial cell types on which H-2 antigens can not be detected by immunoferritin labeling. The apparent absence of H-2 antigens from these cells suggests a study of the viability of beta-cells in allografts of dissociated islet cells, in which the beta-cell would not be in contact with antigenic cells. Such studies might lead to a new approach to the control of diabetes mellitus by transplantation.

Animals↗
PubMed1979

Diversity of expression of H-2 antigens on mouse liver cells demonstrated by immunoferritin labeling.

Antigens of the mouse H-2 locus were studied on isolated liver cells by immunoferritin labeling. Cell suspensions were obtained by gentle homogenization of mouse livers that had been perfused with hypertonic sucrose to loosen cell junctions. Hepatocytes showed sparse labeling of H-2 antigens on the order of 1% of that present on peritoneal monocytes. The slight hepatocyte labeling appeared to be specific for the H-2 locus, since there was essentially no label on congenic control hepatocytes. Other cells in the liver cell preparations were more heavily labeled. Bile duct epithelial cells showed heavy labeling on their lateral surface membranes, but none on their apical brush borders. The preparations contained another nonparenchymal cell type that was densely labeled, but it was not positively identified. Spleen lymphocytes added to liver homogenates and carried through the cell isolation procedure with liver cells showed typically heavy ferritin labeling. These observations suggest that the expression of histocompatibility antigens by tissue cells is likely to be quite variable.

Animals↗
PubMed1979

An immunoferritin labeling study of H-2 antigens on dissociated epithelial cells.

This report describes an immunoferritin labeling study of mouse H-2 histocompatibility antigens on epithelial cells dissociated from stomach, duodenum-jejunum, ileum, trachea, diestrus uterus, gall bladder, and vas deferens. Before cell dissociation, most of the organs were prefixed in periodate-lysine-paraformaldehyde to preserve the shape of the cells and to immobilize H-2 antigens in their native positions. Five kinds of epithelial cells expressed H-2 antigens on lateral and basal membranes but not on apical membranes. These were the lining cells of the upper intestine, ileum, gall gladder, uterus, and the tracheal brush cell. The antigens were continuously distributed on the lateral and basal membranes of these cells and appeared to be absent from the apical membranes, rather than masked by the fuzzy coat. On four other epithelial cell types H-2 antigens could not be detected. These were the lining cells of the vas deferens, parietal and chief cells from the stomach, and ciliated tracheal cells. It does not seem to be uncommon for normal nucleated cells to lack H-2 antigens. On fixed and labeled epithelial cells from the upper intestine the zonula occludens membranes were unlabeled, while the zonula adherens and desmosome membranes were labeled as densely as the remainder of the lateral membranes. The zonula occludens membrane thus constituted the boundary betewen the unlabeled apical membrane and the labeled lateral membrane of these cells. Intestinal epithelial cells dissociated without prefixation showed a patchy distribution of H-2 antigens on their lateral membranes after indirect labeling, indicating antigen mobility in this membrane. On the same unfixed dissociated cells the antigens were able to migrate from lateral to apical membranes, a movement which appears to be prevented in the intact epithelial layer by the occluding junction. The absence of H-2 antigens from apical membranes and their inability to migrate through an intact zonula occludens suggest that these molecules must reach the lateral membranes of epithelial cells by a pathway which is distinct from that followed by apical membrane components.

Animals↗
PubMed1979

The occurrence and distribution of H-2 antigens on mouse intestinal epithelial cells.

This report describes an immunoferritin labeling study of mouse H-2 histocompatibility antigens on epithelial cells dissociated from the small intestine by EDTA and trypsin. Before cell dissociation, the intestine was prefixed in paraformaldehyde or periodate-lysine-paraformaldehyde in order to preserve the shape of the cells and to immobilize H-2 antigens in their native positions. The results demonstrated the presence of H-2 antigens on the lateral and basal cell membranes at about the same high density that was observed at the surface of mouse monocytes. No H-2 antigens could be detected at the apical surface of dissociated or undissociated epithelial cells. It is unlikely that the fuzzy coat masked H-2 antigens at the apical surface because it was essentially absent from the apical membranes of dissociated cells. These observations extend our knowledge of the cellular distribution of transplantation antigens, and provide further evidence of a discontinuity in the expression of membrane components at the junctional complex of epithelial cells.

Animals↗
PubMed1979

Intracellular labeling with ferritin conjugates. A specificity problem due to the affinity of unconjugated ferritin for selected intracellular sites.

Nonspecific binding of ferritin to chromatin and the cytoplasmic aspect of the nuclear envelope was observed when nonantigenic, serum-washed hepatocyte nuclei were incubated in ferritin-antibody conjugates. This labeling was duplicated when nuclei from a wide range of species and cell types were exposed to unconjugated ferritin. Unconjugated ferritin binding to nuclei did not depend on a subpopulation of denatured molecules or on the ferritin purification procedure. Binding occurred equally on unfixed and formaldehyde-fixed nuclei, but no ferritin bound to glutaraldehyde-fixed nuclei. Inconjugated ferritin also bound to the cytoplasmic aspects of the rough endoplasmic reticulum and the plasma membrane. The tracer did not bind to lysosomes, mitochondria, Golgi vesicles, the extracellular surface of plasma membranes, or the intracisternal surfaces of ruptured nuclear envelopes. The addition of 0.4 M KCl or 0.7 M NaCl to ferritin solutions and washing media at neutral pH reduced the binding of conjugated and unconjugated ferritin to nuclei to about 3% of that seen in 0.10 M phosphate buffer alone. The added salts caused little extraction of nuclear contents from formaldehyde-fixed nuclei. The use of one of these salts in ferritin conjugates should considerably improve the specificity of intracellular labeling.

Affinity Labels↗
PubMed1979

Adolescent blood pressure in Richmond, Virginia, schools.

The blood pressure of 3,166 adolescents was measured periodically in Richmond during the period 1974-1977. The subjects were students in public and private schools and ranged in age from 14 to 18 years. Analysis of the readings showed minimal differences relating to age, sex, school and race but a strong correlation with obesity. Only two organic renal causes of hypertension were discovered. A 3 1/2-year followup of 902 students indicated significant tracking, with a correlation coefficient of .385 for systolic and .305 for diastolic pressure. At the conclusion of the study, 340 students (10.7%) were identified as needing followup for hypertension.

Adolescent↗
PubMed1978

Successful intracardiac repair of the Taussig-Bing malformation in 2 children.

Surgical repair of the Taussig-Bing deformity has been successful in 2 children weighting 7.7 and 11.1 kg, respectively. In the first case the right ventricular patch divered left ventricular blood to the pulmonary arter, thus creating a physiologically complete transposition which was then corrected by an interatrial Mustard baffle. In the second case a right ventricular tunnel diverted left ventricular blood to the aorta, and right ventricular blood was directed to the distal pulmonary artery by means of an external conduit bypassing a subpulmonic stenosis. These patients represent the seventh and eighth successful corrections of the Taussig-Bing anomaly. One case (Patient 2) is the youngest to undergo repair and the first to receive an external conduit for bypass of an associated subpulmonic stenosis.

Age Factors↗
PubMed1978

Uptake and fate of ferritin in the uterine epithelium of the rat during early pregnancy.

The ingestion of ferritin injected into the uterine lumen for 20 min was followed by light and electron microscopy. Uptake occurred on Days 4 to 6, with a distinct peak of activity on Day 5 when blastocysts are present in the uterine lumen. At this time, the antimesometrial cells took up more tracer than those on the mesometrial side. The ferritin was located in various types of organelles which contained acid phosphatase, indicating that the tracer entered the lysosomal system. Ferritin-containing lysosomes were essentially all located in the apical half of the cells at 1 h after the injection, but thereafter were distributed throughout the cell. There appeared to be some digestion of ferritin by 48 h, but no evidence for exocytosis of the tracer at the base of the cells was found with light or electron microscopy.

Acid Phosphatase↗