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J D Reynolds

Publications and source records attributed to J D Reynolds.

At least 73 records · Page 4Linked to original sources
PubMed1988

T and B cells have similar recirculation kinetics in sheep.

T and B cells continually migrate around the body by recirculating between blood and lymph via lymphoid tissues. This is an important way of fostering the cell-cell interactions required for the initiation of an immune response. Data from previous studies of T and B cell recirculation, based on relatively complex approaches, have been interpreted as evidence that the recirculation of B cells is more sluggish than for T cells. We have shown from a study in sheep that this is not the case. Lymphocyte migration through both the intestine and the prescapular lymph node was analyzed by cannulating efferent lymphatics. The lymph cells were labeled in vitro with Hoechst 33342, or other fluorochromes, then injected i.v., and the rate of their recirculation into the lymph was determined by fluorescence microscopy. A multicolor immunofluorescence assay was used to classify each recirculated cell as either a T or B cell. This established that the T and B cells from intestinal lymph and from prescapular lymph recirculate with similar kinetics. The recovery of i.v. injected T and B cells was the same in prescapular lymph, but fewer injected B cells than T cells were recovered in intestinal lymph. Thus, although the recirculation kinetics are the same for T and B cells, the two populations are handled differently in intestinal tissues and a lymph node remote from the gut.

Animals↗
PubMed1987

Peyer's patches export lymphocytes throughout the lymphoid system in sheep.

The lymphocyte output from small intestine containing either the long continuous ileal Peyer's patch (PP) or several smaller jejunal PP was examined in young lambs. Most studies were done in 2-mo-old lambs, 1 mo after removal of mesenteric lymph nodes (MLN). Extracorporeal perfusion of part of the intestine and addition of fluorescein isothiocyanate to the perfusate led to the labeling, in their normal microenvironment, of a regionally defined population of cells. One day later considerable numbers of emigrant lymphocytes were identified by fluorescence microscopy in the spleen, MLN and peripheral lymph nodes, jejunal PP, and bone marrow. In nonperfused ileal PP and thymus the labeling indexes were low. The highest labeling index was in the blood where 3.7% of the lymphocytes were labeled. A similar organ distribution of emigrant cells was found on day 3. When MLN were included in the perfused region more emigrants were identified. In some animals the intestinal lymphatic draining the perfused ileum was cannulated. Continual lymph drainage caused a dramatic decrease in the labeling indexes in other lymphoid organs. A substantial number of lymphocytes leave both ileal PP and jejunal PP via lymphatics and travel to all other lymphoid organs. However, the number of emigrant lymphocytes compared with the total number of labeled lymphocytes in the perfused tissue was about 10 times greater after perfusing gut with the jejunal PP than after ileal PP perfusion. We conclude that relatively more lymphocytes emigrate from the jejunal PP than from the ileal PP.

Animals↗
PubMed1987

Mitotic rate maturation in the Peyer's patches of fetal sheep and in the bursa of Fabricius of the chick embryo.

The metaphase arrest technique was used to quantitate the mitotic rate in sheep Peyer's patches (PP) and in the chicken bursa of Fabricius. It was shown that the mitotic rate in these tissues was the same whether or not the animal had been exposed to extrinsic antigen. The mitotic rate was calculated from the rate of accumulation of metaphase cells in tissue sections taken up to 4 h after i.v. vincristine. The follicular B cells in PP of fetal sheep at 3-5 days before birth, and in the bursas of chick embryos 2-3 days before hatching, none of which had experienced extrinsic antigen, entered mitosis at a rate of 5.2%/h and 7.5%/h, respectively. A similar analysis was done on animals at approximately 6 weeks of age, at which stage the PP and bursa had received chronic exposure to antigen from the gut. The mitotic rates were not significantly different from those in fetuses, i.e., 5.4%/h for PP and 6.0%/h for the bursa. In the follicles of both young lambs and juvenile chickens, the mitotic rate was 2-3 times greater in the outer, or cortical zone, than in the inner, or medullary zone. In a similar study of the thymus, no significant differences were found between the mitotic rates in fetal sheep and young lambs. The mitotic rate for the thymus was 15-20-fold less than for the PP. It is proposed that sheep PP, the chicken bursa and the thymus have in common the important characteristic of establishing a maximal rate of lymphocyte division prior to being exposed to antigen.

Anesthesia↗
PubMed1986

Congenital herpes simplex retinitis.

An 1,810-g girl born at 37 weeks of gestation had true congenital herpes simplex virus type 2 infection. The neonate was born with hypo-pigmented skin lesions, brain lesions, and old heavily pigmented retinal scars in the posterior pole. There was no active ocular disease. Viral cultures, immunoperoxidase stains, and antibody determination by enzyme-linked immunosorbent assay were all positive for herpes simplex virus. Treatment with acyclovir healed the lesions within ten days. The clinical and laboratory findings indicated that the herpetic infection probably occurred in the second trimester.

Female↗
PubMed1986

Evidence of extensive lymphocyte death in sheep Peyer's patches. I. A comparison of lymphocyte production and export.

The metaphase arrest technique was used to determine the rate at which cells divide in the Peyer's patches (PP) and the thymus of 5 to 8 wk old lambs. The metaphase indices of these tissues were determined by analyzing cell suspensions of tissues taken before and 1, 2, 3, and 4 hr after metaphase arrest was initiated with i.v. vincristine. The metaphase indices increased in both tissues at a linear rate, which provided an estimate of the rate at which cells entered mitosis and of the lymphocyte birth rate. The ileal PP had the highest lymphocyte birth rate, 2.8% of the lymphocytes entered mitosis each hour; the rate was lower in jejunal PP (1.0%/hr) and thymus (0.5%/hr). With these values and estimates of the lymphocyte content in all PP (1.45 X 10(11)) and in the thymus (1.71 X 10(11)), it was calculated that the hourly lymphocyte production by PP in a lamb was 3.61 X 10(9) cells, which is four to five times greater than for the thymus (0.82 X 10(9)). Lymphocyte production in PP could then be compared with the number of lymphocytes that emigrated from the small intestine. Newly produced cells leave PP via the intestinal lymph, which could be collected from the entire small intestine after removal of the mesenteric lymph nodes. Cells entered the lymph at a rate of 0.8 X 10(9)/hr, but the output fell rapidly during chronic lymphatic drainage, a procedure known to deplete long-lived recirculating cells. It was concluded that most of the cells in intestinal lymph were recirculating cells, and newly formed lymphocytes produced in PP probably account for less than 25% of the total or 0.2 X 10(9)/hr. It seems unlikely that emigration could occur at a rate comparable with the rate of production in the PP. At most, only 5% of the PP cells seemed destined to leave their site of production, and it is proposed that most die within the PP follicles. The high mortality rate associated with the production of large numbers of B lymphocytes in lamb PP seems likely to have a significant impact on the nature of the contribution that these tissues make to the immune system.

Animals↗
PubMed1986

Evidence of extensive lymphocyte death in sheep Peyer's patches. II. The number and fate of newly-formed lymphocytes that emigrate from Peyer's patches.

The emigration of newly produced lymphocytes from Peyer's patches (PP) of lambs was studied. Mesenteric lymph nodes (MLN) were excised from most animals a few weeks after birth, and then at 8 to 10 wk of age, the dividing cells in 3 to 4 m of the small intestine were labeled in situ with [3H]thymidine. An extracorporeal perfusion system was used to restrict the 15-min period of labeling to the perfused lengths of intestine, which included either the large continuous ileal PP or a number of smaller jejunal PP. One or 3 days later, the number of labeled cells in the perfused tissue and in other lymphoid organs was studied by autoradiography. In the perfused tissues, labeled lymphocytes accounted for 63.7% of ileal PP cells by 1 day and for 86.7% by 3 days compared with only 9.6% of lymphocytes in the perfused MLN. Labeled lymphoid cells in the perfused PP were nearly all in the follicles. Labeled lymphocytes that must have been produced in the segments of ileum or jejunum at the time of the perfusion, subsequently emigrated via the lymphatics, and were identified in the spleen, MLN, other lymph nodes, blood, jejunal PP, and at a lower frequency in the thymus, nonperfused ileal PP, and bone marrow. In lymph nodes, spleen, and nonperfused PP, more than 80% of the immigrant newly formed PP-derived cells were small- and medium-sized lymphocytes, and about 15% were large lymphocytes. The nature of the labeled cells in the lamina propria of the nonperfused small intestine was quite different in that approximately 50% were plasma cells as early as 24 hr after the cells were born in the perfused gut. It is proposed that terminal B cell differentiation was most likely initiated within the PP in response to the entry of antigen. It was estimated that at both 1 and 3 days after perfusion there were about 100 times more labeled cells in the perfused ileal PP than could be accounted for by emigration to other organs. It was concluded that these results provide additional support for the view that PP in lambs produce a tremendous number of lymphocytes, but relatively few leave their site of production; most apparently die in situ.

Animals↗
PubMed1985

Aflatoxin-induced alterations in Glycine max, cv. 'Essex' root cell membrane protein content.

Aflatoxins (AFTs) are hepatocarcinogens, mutagens, teratogens and toxins. Isolates of AFTs-producing strains of Aspergillus flavus can grow upon both autoclaved soybeans and to a lesser extent field-grown beans. Besides inhibiting the elongation of excised, in vitro cultured soybean roots, the AFTs can impair the roots' ability to remove [14C]-leucine from a culture medium and to incorporate the amino acid into acid-insoluble, cytoplasmic protein. In this connection, exogenous AFTs once taken-up and compartmentalized by the excised roots can reduce the acid-insoluble protein content of what appears to be a non-enriched plasmalemma fraction. Here, we report a combined biochemical and microscopical attempt to determine whether the protein reduction occurs throughout the excised, in vitro-cultured root and whether the plasmalemma proteins which are affected by AFTs can be both solubilized and characterized. Histochemistry of Carnoy-fixed roots revealed a reduction in Ninhydrin-Schiff-stainability throughout the AFTs-treated root. Transmission electron microscopy of 80 000 X g pellets derived from homogenates of both non-treated (NT) and treated (T) roots provided further evidence to our previously reported marker enzyme analyses for the occurrence of the plasmalemma in the 80 000 X g pellet. Treatment of the latter with the Laemmli SDS procedure released greater than 85% of the protein associated with the pellets obtained from homogenates of either NT or T roots. Gel permeation chromatography on Biogel-100 of released proteins from 80 000 X g pellets of both NT and T roots yielded both void volume and retarded peaks. Both the amplitude and the quantities of protein recovered within the void volume peak were less within the void volume of the t than the NT root. Polyacrylamide tube gel electrophoresis of G-100 void volume peaks of chromatographed, SDS-released proteins from the pellets revealed quantitative but not qualitative differences in Coomassie Blue-gel staining patterns between T and NT roots. These results suggest that the SDS methods which we employed could solubilize the 80 000 X g pellet proteins but that combined gel permeation chromatography and tube gel electrophoresis were not sensitive enough to reveal whether AFTs could alter the types of proteins associated with the 80 000 X g pellet (purported plasmalemma).

Aflatoxins↗
PubMed1985

Association of bilateral internuclear ophthalmoplegia and myelomeningocele with Arnold-Chiari malformation, type II.

We describe the unusual association of long-standing repaired myelomeningocele, hydrocephalus, and Arnold-Chiari malformation with bilateral internuclear ophthalmoplegia in a young man. A rarely reported association, this case emphasizes the need for further neuroradiologic evaluation to determine the possibility of third-ventricle enlargement with worsening hydrocephalus.

Arnold-Chiari Malformation↗