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Biomedical subjects

W T Gunning

Publications and source records attributed to W T Gunning.

28 records · Page 2Linked to original sources
PubMed1983

Clonal growth and serial propagation of rat esophageal epithelial cells.

The clonal growth and serial propagation of rat esophageal epithelial cells in low serum-containing medium has been achieved without feeder layers or conditioned medium. To date, a total of four lines have been developed and maintained for as many as 40 passages in culture. Growth of the cells was possible only after modifying the culture medium (PFMR-4) by reducing the calcium concentration from 1 to 0.1 mM, and by adding low levels of dialyzed fetal bovine serum and seven growth factors; i.e. epidermal growth factor, hydrocortisone, ethanolamine, phosphoethanolamine, insulin, transferrin, and cholera toxin. Cell lines have been developed from both explant outgrowths and enzyme dissociated esophagi. The epithelial nature of the cells was confirmed by electron microscopy and immunological methods. Clonal growth studies revealed that optimal cell growth occurred in medium containing 2.4% dialyzed fetal bovine serum and 0.1 mM calcium. Calcium levels of 0.3 mM or higher caused the cells to stratify and undergo terminal differentiation. Coating the culture dishes with collagen, or a combination of collagen, fibronectin, and bovine serum albumin, increased both the cell growth rate and the colony forming efficiency. The successful long term culture of rat esophageal epithelial cells permits their use as models in studies concerned with esophageal differentiation and carcinogenesis.

Animals↗
PubMed1982

In vitro transformation of rat esophageal epithelial cells with N-nitrosobenzylmethylamine.

Using an explant/cell culture system, rat esophageal epithelial cells were transformed in vitro by exposure to N-nitroso-N-benzyl-N-methylamine (BMNA). Twelve esophageal explant cultures per group were exposed twice (at days 1 and 7) to 0.0, 2.5, 5.0 or 10.0 micrograms BMNA/ml of medium. After incubation for 60-90 days, epithelial cells in primary cultures treated with all three concentrations of BMNA could be subcultured and cell lines were developed. The number of primary cultures and the number of subsequently developed epithelial cell lines was carcinogen-dose-dependent. Cell lines could only be established from carcinogen treated explants. Electron microscopy revealed that the BMNA-treated cell lines contained morphological markers of esophageal epithelial cells; i.e., numerous tonofilaments and junctional complexes, even after prolonged subculture. By immunofluorescence, the cells reacted positively with antibodies prepared to mouse skin prekeratins (K1 and K2). Two cell lines (from the 5 micrograms BMNA/ml group) were able to grow in soft agar and produce palpable tumors upon injection into syngeneic recipients. These tumors possessed the histological features of squamous cell carcinomas.

Animals↗
PubMed1982

Chronic serum sickness in the mouse. Relationship of antigen dose to glomerular pathology.

We studied the effect of the administration of different doses of antigen in a model of chronic glomerulonephritis produced in mice by the daily injection of apoferritin. Four groups of mice received intraperitoneal injections of 4 mg apoferritin (group 1), 2 mg apoferritin (group 2), 1 mg apoferritin (group 3), or saline (group 4) daily. Significant proteinuria and the presence of antiapoferritin antibody were demonstrated in mice immunized with apoferritin. The severity of histologic damage and the extent of staining for IgG significantly increased with larger doses of apoferritin. Electron microscopy revealed subepithelial and mesangial electron-dense deposits. Administration of large daily doses of apoferritin to mice results in a reliable model of immune complex glomerulonephritis and crescent formation.

Animals↗
PubMed1982

Suppression of antibody synthesis by prostaglandin E as a mechanism for preventing murine immune complex glomerulonephritis.

A model of immune complex glomerulonephritis induced in mice by the daily injection of 4 mg. of apoferritin was used to examine the effect of administration of two prostaglandins, PGE1 and PGE2. The twice daily administration of either PGE1 or PGE2 in pharmacologic doses resulted in significantly less glomerular damage and a shift in the primary location of immune complex deposition from the capillary loops to the mesangium, as demonstrated by immunofluorescence and electron microscopy. The beneficial effect of the prostaglandins was associated with a significant decrease in antiapoferritin antibody levels. A separate study was performed to determine whether the mechanism of decreased antibody levels produced by PGE administration was related to a decrease in the number of plaque-forming cells (PFC). Mice received injections of saline, apoferritin, or apoferritin plus PGE2 for 9 days, and spleen cells were used to determine the number of direct and indirect PFC. No direct PFC were detected in any of the groups. There was no difference in the number of indirect PFC between mice receiving apoferritin and those receiving apoferritin plus PGE2 (98 +/- 13 versus 108 +/- 30), whereas mice receiving saline had no indirect PFC. The prevention of glomerular damage in immune complex glomerulomephritis and the shift in the site of complex deposition induced by PGE1 and PGE2 appear to be caused by reduction in specific antibody synthesis. This reduced synthesis is not related to an alteration in the number of antibody-producing cells.

Animals↗
PubMed1980

Prostaglandin E1 therapy of murine chronic serum sickness.

We studied the effect of PGE1 in pharmacologic doses on immune complex-induced glomerulonephritis produced by daily intraperitoneal injections of apoferritin. Mice received one of the following injection schedules: apoferritin 4 mg/day, apoferritin 4 mg/day plus PGE1 200 microgram twice daily, saline, or PGE1 200 microgram twice daily. Administration of apoferritin alone resulted in mesangial cell proliferation in all 14 mice with crescent formation in nine. Evidence of subepithelial and mesangial immune complex deposition and a significant increase in urine protein excretion was found. Treatment with PGE1 resulted in a mild increase in mesangial cells in six of 14 mice. No mice developed crescents on this regimen. In addition, proteinuria was prevented, and there was a marked diminution of immune complex deposition. Antiapoferritin antibody was detected in the sera of mice from both groups. No alteration in lymphocyte response to mitogen or in vitro PGE1 suppression of blastogenesis was detected. Our results indicate that PGE1 therapy alters immune complex glomerulonephritis in this model of murine chronic serum sickness by reducing glomerular immune complex deposition. However, no difference in specific or nonspecific immunologic responses was detected.

Animals↗
PubMedDate not supplied

Carnitine deficiency associated with ornithine transcarbamylase deficiency.

An infant with X-linked recessive ornithine transcarbamylase deficiency is described who also had severe deficiency of plasma and liver carnitine during normoammonemic periods. Treatment with L-carnitine (100 mg/kg/day) for 12 months decreased the frequency of hospitalizations for hyperammonemia, although it did not alter his neurologic status. This report demonstrates that persistent carnitine deficiency may be present in patients with ornithine transcarbamylase deficiency even when plasma ammonia is normal. Carnitine evaluation and supplementation may be important in the treatment of patients with this metabolic disorder.

Amino Acid Metabolism, Inborn Errors↗
PubMedDate not supplied

Glyceraldehyde-3-phosphate dehydrogenase and other enzymatic activity in normal mouse lung and in lung tumors.

The histogenesis of chemically induced mouse lung adenomas is currently being debated. Tumors induced by a variety of chemicals and in a number of different strains exhibit growth patterns having a solid/alveolar appearance, a papillary appearance, or a mixture of both. Ultrastructural observations suggest that solid tumors are derived from the alveolar type II pneumocyte and that papillary tumors arise from the bronchiolar Clara cell. However, recent immunocytochemical investigations have concluded that most mouse lung tumors are derived solely from the alveolar type II cell. Enzyme histochemical methods have previously been utilized to identify Clara cells in pulmonary cell isolates and also to characterize mouse lung tumors. This report demonstrates a difference in glyceraldehyde-3-phosphate dehydrogenase (G3PD) activity in type II pneumocytes and Clara cells. Solid tumors and type II cells appear to have a similar G3PD activity, and this activity is different from that observed in papillary tumors and bronchiolar cells. These findings support morphological evidence that suggests mouse lung tumors are phenotypically different and may arise from at least two different cells of origin.

Adenoma↗
PubMedDate not supplied

Ultrastructure of the interstitial cells of Leydig, stimulated and unstimulated.

The interstitial cells of Leydig which lie in small groups or individually between the seminiferous tubules of the testes, or at the hilum in the ovary, are known to be active in production of androgenic substances, as well as being sensitive to the influence of various trophic hormones. Among the hormones known to be produced by these cells are testosterone, dihydrotestosterone, and estradiol. Responsiveness of the function of the Leydig cells has been demonstrated with luteinizing hormone (LH), growth hormone, follicle stimulating hormone (FSH), and probably estrogen as well as prolactin. Human chorionic gonadotrophin also may have a marked effect. Attempts to correlate the cytologic appearance of Leydig cells with various states of stimulation have revealed a number of ultrastructural appearances. Since a spectrum of cellular morphology is apparent, both in the normal and in altered physiologic states, it is hazardous to ascribe a particular ultrastructural variation to the influence of a given hormonal stimulus. Nevertheless, in normal males, three types of cells can frequently be seen: fusiform cells with ovoid nuclei, small aggregates of smooth endoplasmic reticulum (SER), and variable amounts of cytoplasmic filaments, probably representing resting cells, since they are most abundant in pre-pubertal males; light cells, the most frequent type, with well developed SER, scant rough endoplasmic reticulum (RER), and mitochondria which vary in size and shape, contain abundant lipid and frequent lipochrome deposits; and dark interstitial cells which are variable in number, derive their density from stacks of tubular SER, and may represent merely an altered response to fixation or an involutional form. In addition to immature cells and normal mature cells, two additional cell types are described in various primary testicular disorders: abnormally differentiated Leydig cells with features such as grouped mitochondria, whorls of endoplasmic reticulum, absent or fragmented Reinke's crystals and paracrystalline arrays and deficiency of lipid droplets as well as masses of microfilaments; and a multivacuolated cell type characterized by swelling of cytoplasmic organelles and absence of Reinke's crystals or paracrystalline arrays. It is also clear that the interstitial cells respond in systemic diseases, are injured by alcohol ingestion, and show involutional changes in aging. While these ultrastructural changes are now well documented, there is still a need to correlate them exactly with the various stimuli which may affect testicular function.

Aging↗
PubMedDate not supplied

Ultrastructure of the liver and biliary tract in health and disease.

Ultrastructural studies with the transmission (TEM) and scanning (SEM) electron microscopes have added greatly to our knowledge of cellular structure and function in the liver. The normal polyhedral hepatocyte has numerous subcellular organelles, such as mitochondria, peroxisomes, lysosomes and complex rough (rer) and smooth (ser) endoplasmic reticulum. The normal hepatocyte stores glycogen, and sometimes lipid droplets, and secretes bile through the bile canaliculi between adjacent liver cells. It receives nutrients from the sinusoidal lumen across a fenestrated endothelium which is separated by the Space of Disse' from the plasma membrane. The Space of Disse' contains a scant network of reticulin fibers but no basal lamina. Two types of parasinusoidal cells are found in Disse's space: the fat storing cells of Ito, and the Pit cells which may have an endocrine function. The diseased liver has yielded much information in studies with TEM and SEM. The studies with TEM have been most helpful in studying the etiology of infectious diseases such as hepatitis B; have revealed organelle changes such as megamitochondria in cirrhosis and the fibrillar nature of alcoholic hyaline; have led to the identification of specific deposits in metabolic and storage diseases such as hemochromatosis (iron). Wilson's disease (copper), and alpha-1-antitrypsin deficiency (glycoprotein) have proven useful in identifying drug induced liver cell changes such as proliferation of SER and cholestasis, and are useful for identifying specific cell types in inflammatory and neoplastic diseases. In the future, both TEM and SEM coupled with histochemical, cytochemical, immunohistochemical and other analytic techniques will continue to add greatly to our understanding of the liver in health and disease.

Bile Duct Diseases↗