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L L Seelig

Publications and source records attributed to L L Seelig.

At least 37 records · Page 2Linked to original sources
PubMed1989

A morphometric study of the effects of ethanol consumption on lactating mammary glands of rats.

Morphometric procedures were used to quantitate changes induced by ethanol in tissue components of rat mammary gland. Rats were pair-fed ethanol-containing or isocaloric control liquid diets formulated for pregnant or lactating animals, or maintained on regular laboratory chow. Short term animals were pair-fed ethanol or control diets from Day 1 of pregnancy through lactation Days 2 or 10. Long term animals were pair-fed ethanol or control diets for 25 days prior to mating, and then through pregnancy to lactation Days 2 or 10. Point counting was used to determine the volume fractions (vf) of alveolar epithelium, lumen, and connective tissue in the mammary glands. In chow-fed animals the percentage of alveolar epithelium remained constant from late pregnancy through lactation, while the amount of connective tissue decreased and that of alveolar lumen increased. This indicates the sensitivity of this procedure to detect changes in tissue volume fractions during mammary proliferation. No changes from the normal controls were found in any tissue component in short term ethanol or pair-fed animals. At lactation Day 2, long term ethanol-treated animals demonstrated a significant decrease in the percentage of alveolar epithelium and a significant increase in the percentage of total connective tissue as compared to pair-fed and chow-fed control animals. However, by Day 10 of lactation, no changes were found in any of the tissue components in long-term ethanol-fed versus control animals. These results indicate that ethanol consumption can alter mammary gland structure during the early stages of lactation, even when adequate levels of dietary protein are maintained.

Animals↗
PubMed1989

Maternal to neonatal transmission of T-cell mediated immunity to Trichinella spiralis during lactation.

The potential of maternally derived cellular factors to mediate immunity to Trichinella spiralis in neonates during lactation was investigated in this study. Female FI rats, infected with T. spiralis, were able to transfer immunity to their suckling offspring, evidenced by a significant reduction in the intestinal parasite burdens of their neonates. When challenged between 2 and 3 weeks of age with 200 T. spiralis larvae, pups suckling on immune mothers harboured 28% and 26% (at 3 and 8 days post-challenge) of the worm numbers present in control neonates suckling on naive mothers. Cross-fostering experiments in which pups born of naive mothers but nursed by immune mothers showed significant immunity, demonstrated that this passage occurred through milk. The role of cell-mediated immunity in this immune transfer was analysed using T cells purified from MLN cells of syngeneic donor rats infected with T. spiralis. When 200 x 10(6) sensitized MLN T cells were adoptively transferred into lactating recipients, it led to the passive immunization of suckling neonates (26% and 13% of control values retained at 3 and 8 days post-challenge), while maternal injection of T cells primed to an irrelevant antigen (KLH) had no effect on neonatal immunity. Neonates fed per-orally with primed T lymphocytes early in lactation and prior to challenge were also rendered immune (34% and 44% of control values retained at 3 and 8 days post-challenge). A single dose of T. spiralis-primed T cells given to neonates in early lactation was sufficient to elicit a significant immune response in them at 2 weeks of age. These results support the hypothesis that cellular immunity mediated by antigen-specific T cells in milk can provide functional immune protection to the neonate against an intestinal pathogen.

Animals↗
PubMed1988

Immunohistochemical analysis of the stage-specific expression of Ia antigens in the rat mammary gland during pregnancy and lactation.

The expression of Class II MHC antigens in the rat mammary gland was assessed by immunoperoxidase using monoclonal antibodies against rat homologues of the murine I-A and I-E antigens. Our results showed that, while I-A and I-E were inconspicuous in undifferentiated mammary epithelium in virgin rats, during early pregnancy, the ductal epithelium becomes intensely positive for both antigens. A monoclonal antibody specific for macrophages showed that they were abundant in the stroma but did not correspond to the epithelial staining. During late pregnancy and lactation, the ductal epithelium expressed varying levels of Ia, while the alveolar epithelial cells were consistently Ia-negative. Ia-positive mononuclear cells of round or dendritic morphology present in the alveolar areas were enumerated as cells per high power field (HPF). Maximal cell counts for I-A and I-E were seen in late pregnancy and early lactation, with a significant decline in mid-lactation. Counts were higher in intraepithelial locations than in the subjacent connective tissue at all stages. The possible role of these stage-specific alterations in regulating local immune responses and transfer of immune components into milk is discussed.

Animals↗
PubMed1988

Ultrastructural morphometric analysis of lesional skin: mast cells from patients with systemic and nonsystemic mastocytosis.

Lesional skin mast cells from some patients with mastocytosis appear morphologically atypical; however, these subjective differences have not been quantified. Herein we describe an objective method for analyzing cutaneous mastocytosis mast cells by a combination of morphometric analysis and electron microscopy. By this technique, lesional mast cells from patients with adult systemic mastocytosis had a significantly larger mean cytoplasmic area (53.3 microns2), nuclear size (20.4 microns2), and granule diameter (0.81 micron) when compared with mast cells from adults with nonsystemic mastocytosis (36.3 micron 2, 15.4 microns2, and 0.67 micron, respectively) and normal age-matched control subjects (34.4 microns2, 14.1 microns2, and 0.67 micron, respectively). Lesional skin mast cells from infants with nonsytemic mastocytosis were very similar to adult nonsystemic mastocytosis mast cells but differed by several parameters from mast cells in adults with systemic involvement. This study demonstrates that there are quantitative differences between lesional skin mast cells from patients with systemic mastocytosis and those with nonsystemic disease.

Adult↗
PubMed1988

Ultrastructural morphometric analysis of human mast cells in normal skin and pathological cutaneous lesions.

Electron micrographs of human mast cells in normal neonatal and adult skin and in cutaneous lesions of basal cell carcinoma (BCC), hemangioma and mastocytosis were assessed by morphometric analysis. Using this quantitative histologic approach, adult skin mast cells were found to be significantly larger (47.7 microns 2 +/- 2.4 SEM vs. 38.3 microns 2 +/- 1.8 SEM, p less than or equal to 0.001) and have larger granules (0.63 micron +/- .02 SEM vs. 0.53 micron +/- .02 SEM, p less than or equal to 0.001) than infant mast cells while both mast cell populations had comparable nuclear sizes (13.7 microns 2 +/- 0.9 SEM vs. 14.3 microns 2 +/- 0.8 SEM) and numbers of cytoplasmic granules (72 +/- 4.0 SEM vs. 66 +/- 4.0 SEM). Morphometric analysis of mast cell infiltrates in the adult skin lesions of BCC and hemangioma revealed that these cells were larger than neonatal mast cells but were similar to normal adult controls. Cutaneous mast cells from 2 mastocytosis patients, however, had significantly larger mean cell surface areas (78.0 microns 2 +/- 3.4 SEM and 70.6 microns 2 +/- 3.2 SEM, p less than or equal to 0.001), nuclear areas (20.8 microns 2 +/- 1.1 SEM and 21.3 microns 2 +/- 1.2 SEM p less than or equal to 0.001) and granule diameters (0.82 micron +/- 0.4 SEM and 0.83 micron +/- .03 SEM, p less than or equal to 0.001) when compared with mast cells in normal adult skin and in the other pathologic lesions. No difference in the total number of cytoplasmic granules was observed in the different mast cell populations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Uptake of lymphocytes fed to suckling rats. An autoradiographic study of the transit of labeled cells through the neonatal gastric mucosa.

To determine the potential for transfer of maternal lymphocytes to the newborn during suckling, radiolabeled cells were fed to rat neonates of different ages and autoradiographs prepared from tissue sections obtained from the stomach and small intestine. The entire stomach (including contents) and intestinal walls were observed using semiserial 3 micron methacrylate plastic sections. For these studies 100 X 10(6) [3H]uridine-labeled lymph node cells were fed to 1-4-day-old neonates using a smooth-tipped intubation needle. Some of the lactating female rats had been given radioisotope prior to delivery and "cold" babies were fostered to them to enhance the number of labeled cells in the neonatal digestive tract. Babies were killed at 1, 2, 4, 8, 24 and 48 h after feeding. The stomach contents showed a considerable number of labeled cells (32% at 1 h after feeding) and many of these cells were in close proximity to the epithelium. The gastric epithelium often exhibited gaps between adjacent epithelial cells similar to those we have previously reported in the lactating mammary epithelium, and labeled cells were observed in the immediate area of the gaps. Labeled cells were seen in the neonatal gastric epithelium, lamina propria, mesenteric attachments, in the wall and lumen of small gastric blood vessels and adjacent lymph nodes. Labeled cells were most abundant in the gastric wall at 1-2 h following feeding, indicating that transit through the epithelium occurred rapidly. Although labeled cells were seen in the lumen of the small intestine, none were observed in the tissues of the intestinal wall. When heat-killed labeled cells were fed, no labeled cells were seen in the tissues of the neonatal gastrointestinal tract. It is apparent from these studies that a portion of the leukocytes that are delivered to the neonate during suckling are able to transit the gastric epithelium and establish themselves in the neonate's tissues, presumably to aid in the protection of the immunologically naive infant.

Animals↗
PubMed1987

In vitro functional reactivities of cutaneous mast cells from patients with mastocytosis.

Cutaneous mast cells from 3 patients with mastocytosis were evaluated for their morphologic characteristics and in vitro functional reactivities to different secretory agonists. By electron microscopy, mastocytosis mast cells appeared larger than normal skin mast cells, frequently had atypical, highly indented or bilobed nuclei, and each contained numerous, elongated cytoplasmic projections. Suspensions of mastocytosis mast cells were obtained from lesional skin biopsy specimens, and their response to both immunologic and nonimmunologic secretagogues was compared with mast cells from normal skin. Lesional skin mast cells had a net histamine release of 12.3% (+/- 1.3 SEM) and 31.1% (+/- 6.0 SEM) following stimulation with the purified human anaphylotoxin C3a and mouse monoclonal antihuman IgE antibodies, respectively. This specific release was similar to the responses observed in normal skin mast cells (11.5% +/- 4.5 SEM and 16.7% +/- 2.1 SEM, respectively). Mast cells from cutaneous lesions of mastocytosis also responded to the nonimmunologic secretagogues, morphine sulfate and calcium ionophore A23187 with a specific histamine release of 15.1% (+/- 1.2 SEM) and 39.8% (+/- 8.7 SEM), respectively. The results of this study demonstrate that mast cells from lesions of mastocytosis are morphologically atypical, but have a histamine content similar to normal skin mast cells and retain their functional reactivities to clinically relevant secretory stimuli.

Child↗
PubMed1985

Mucosal nerves and smooth muscle relationships with gastric glands of the opossum: an ultrastructural and three-dimensional reconstruction study.

The precise anatomical relation by which autonomic nerve endings contact gastric epithelial cells to enhance the rate of gastric secretions is not fully understood. The aim of the present study was to clarify this issue by using the technique of serial section reconstruction of areas of the gastric mucosa. The work also explored the possibility of a functional role for a system of smooth muscle strands in the gastric mucosa that emanate from the muscularis mucosa, run in the lamina propria, and are associated in a unique manner with the gastric glands. Electron microscopic serial sections of the gastric mucosa were performed to visualize the entire limiting membrane of gastric epithelial cells to determine any nerve associations (especially varicose endings) with these cells. Evaluation of serial sections of five separate parietal cells showed that their basal membrane did not come in close contact (nearest distance 500 nm) with any nerve axon or varicosity. Moreover, the axons passing in the area of these cells ultimately showed varicose endings associated with smooth muscle cells in the adjacent connective tissue (often separated by only 20 nm), with mast cells or with vascular elements. Additionally, the lateral membrane of these five parietal cells did not contact any endocrine cell in the epithelium, although other parietal cells in the area were adjacent to endocrine cells. Chief cells in the immediate area also did not form any close associations with nerve varicosities. Random analysis of 5,000 additional epithelial cells in these sections showed no close associations to nerve elements with significant accumulations of neurosecretory vesicles (varicosities). Because of the observed existence of innervation to the smooth muscle strands in the area of the gastric glands, serial 1-micron epoxy sections of the gastric mucosa were prepared, and profiles of smooth muscle and gastric glands were entered into a computer-assisted reconstruction system. Three-dimensional reconstruction techniques were employed to reveal the existence of a unique association between the mucosal smooth muscle strands and the gastric glands. The muscle strands arose from the muscularis mucosa at regular intervals and became branched to form an intricate wrap around a series of gastric glands that empty into one gastric pit.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1985

Migration of radiolabeled, adoptively transferred T-lymphocytes into the mammary gland and milk of lactating rats.

The maternal component in the transfer of cellular immunity from the mother to the neonate during lactation was investigated by analyzing the migration of adoptively transferred T-lymphocytes to the mammary gland and into the milk of lactating rats. A T-enriched cell population, containing less than 2.5% of contaminating B-cells, was obtained from mesenteric and peripheral lymph node cells of donor rats by removing B-cells with a panning technique. The T-enriched cells, radiolabeled with [3H]uridine, were injected intravenously into syngeneic lactating females, between 1 and 4 days post-partum. Samples of mesenteric and cervical lymph nodes, spleen, Peyer's patches, small intestine, and mammary gland taken at 48 h and milk obtained at 24 and 48 h were processed for scintillation counting and autoradiography. A large portion of the injected T-cells migrated to T-dependent lymphoid areas (the paracortical and medullary regions of the mesenteric and cervical lymph nodes and the Peyer's patches) and a substantial number also migrated into the small intestine and mammary gland, although the frequency of cells per high-power field was lower than in the lymph nodes. However, total counts of activity recovered were significantly higher in the small intestine and mammary gland than in either the mesenteric or cervical groups of lymph nodes. The distribution of the T-cells within the mammary gland showed a relative predominance of labeled cells in the connective tissue adjacent to the alveolar secretory cells, with a small percentage of cells present within the mammary epithelium. The direct transfer of T-cells through the alveolar epithelium was demonstrated by the presence of labeled cells in milk. These results substantiate that a significant number of T-lymphocytes migrate not only to the mammary gland during lactation but also into milk. These cells may play a passive regulatory or inductive role within the mammary gland or an active role in the maternal-to-neonatal transfer of immunity.

Animals↗
PubMed1985

Conjugated avidin binds to mast cell granules.

The glycoprotein, avidin, conjugated either to the enzyme horseradish peroxidase, or to the fluorochrome dyes, fluorescein or rhodamine, identifies the granules of mast cells in both tissues and cell suspensions. In the absence of prior fixation, mast cells were not identified with conjugated avidin; however, granules released from these cells were stained with this labeled glycoprotein. The specificity of avidin for mast cells was confirmed by the absence of conjugated avidin-positive cells in the skin of mice (S1/S1d) deficient in mature dermal mast cells. Electron microscopic studies confirmed that avidin binds specifically to individual mast cell granules rather than to other cellular structures. Rodent and human mast cells were readily stained with avidin conjugated to horseradish peroxidase or to either of the fluorochrome dyes. The conjugated avidin staining technique is a reliable and simple method for identifying rodent and human mast cells, one that is useful as both an investigative and a clinical tool.

Animals↗
PubMed1984

Acetylcholinesterase and choline acetyltransferase staining of neurons in the opossum esophagus.

The purpose of the present investigation was to identify and compare cholinergic intramural neurons in the lower esophageal sphincter and esophageal body by histochemical staining for acetylcholinesterase and the enzyme that synthesizes acetylcholine, choline acetyltransferase. Opossums were anesthetized and their abdominal cavity was opened by a midline incision to expose the esophagogastric junction. The lower esophageal sphincter was identified manometerically and localized in situ with markers. Tissues were removed, rapidly frozen in freon cooled with liquid nitrogen and serial cryostat sections were obtained from the lower esophageal sphincter and esophageal body. Sections were stained with one of the above histochemical procedures and adjacent sections were stained with Solachrome cyanin , which differentially stains nerve elements from muscle fibers. The muscle of the lower esophageal sphincter and esophageal body was stained with nonspecific cholinesterase with some selectivity of intensity of reaction in the various smooth muscle layers. All identifiable plexus neurons in the esophagus stained for nonspecific cholinesterase and acetylcholinesterase. Nerve fiber tracts were also stained for acetylcholinesterase within the longitudinal and circular layers of the tunica muscularis. Reaction for choline acetyltransferase showed no staining in the muscle layers or nerve fiber tracts of either part of the esophagus studied; however, selected neurons within the myenteric plexus of both regions (approximately 38%) were reactive. There was no significant difference in the number of positive choline acetyltransferase neurons in the lower esophageal sphincter or esophageal body.

Acetylcholinesterase↗
PubMed1984

Spontaneous autoradiographic grain activation associated with mast cells in methacrylate plastic embedded tissue sections.

Autoradiographic tracing using tritium labeled compounds or cells is a common laboratory technique for light and electron microscopy. This report describes a chemographic effect associated with certain cells in sections from tissues embedded in the new methacrylate plastic embedding compounds. When tissue sections from rats and rhesus monkeys that received no radioisotope were coated with nuclear track emulsion and subsequently developed, cells with morphologic characteristics of mast cells showed significant grain formation over the entire cell. Three different types of methacrylate plastics were tested using rat and monkey tissues and all three were found to promote grain formation over mast cells; however, this phenomenon was not seen in similar tissue sections from paraffin or epoxy embedded material. The properties of methacrylate plastics which promote positive chemography by mast cells may reflect the greater permeability of this class of plastics. Due to their wide tissue distribution, the presence of such chemographically active cells could cause false estimates of the distribution of either exogenous radiolabeled cells or radioisotopes within many tissues.

Animals↗
PubMed1983

Autoradiographic analysis of lymphocyte migration into the mammary epithelium and milk of lactating female rats.

Adoptively transferred radiolabeled lymphoid cells migrating to the lactating mammary gland were shown to enter the alveolar epithelium and ultimately the milk. Lactating female rats were injected intravenously with [3H]uridine-labeled syngeneic mesenteric lymph node cells, and the distribution of the cells 24 and 48 h later within intestinal and mammary tissues and their presence in milk were assessed autoradiographically. At both time periods, numerous labeled cells were found in the Peyer's patches and mesenteric lymph nodes. The mammary tissue and intestinal mucosa (lamina propria and epithelium) contained fewer labeled cells per unit area than those sites. Labeled cells within the mammary tissue were distributed equally between the alveolar epithelium and the intralobular connective tissue, where they were seen in both blood vessels and in the loose connective tissue. Occasional labeled cells were observed among the mononuclear cells seen in the alveolar lumina, and an average of 4.8% of the cells harvested from milk samples were labeled. Labeled cells within the secretory epithelium and milk always had the morphologic characteristics of mononuclear leukocytes. Thus, at least a portion of the lymphoid cells which have been shown to migrate to the mammary tissue in increased numbers during lactation actually enter and traverse the epithelium and contribute to the lymphoid component of mammary secretions.

Animals↗
PubMed1981

Capacity of "transplanted" lymphocytes to traverse the intestinal epithelium of adult rats.

Suspensions of viable lymph node cells (LNCs), both unlabeled and 3H-uridine labeled, from adult Fischer (FI) rats were inoculated into the lumens of established, surgically isolated segments of ileum in adult (FI x DA)F1 hybrid hosts. Vascular, lymphatic, and nerve supplies of the isolated segment were preserved. It was reasoned that subsequent hypertrophy of the draining mesenteric LN complex, on an immunogenetically specific basis (attributable to graft-versus-host (GVH) reactivity) and histological identification of labeled lymphoid cells in the intestinal wall of the isolated segment, would be indicative of the passage of inoculated cells across the intestinal epithelium. It was found that host mesenteric LNs were significantly larger on the 8th postinoculation day in animals that received 100 x 10(6) or 300 x 10(6) FI LNCs than in animals that were given similar numbers of syngeneic F1 hybrid cells (controls). This lymph node hypertrophy was dosage dependent and favorably influenced by the presence of Peyer's patches. The results of experiments involving introduction of 3H-uridine-labeled cells into isolated ileal segments and subsequent radioautography corroborated the conclusion that lymphocytes deposited in the intestinal lumen can gain access to host tissues, i.e., they are "naturally transplanted."

Animals↗