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Biomedical subjects

J B Jacobs

Publications and source records attributed to J B Jacobs.

At least 55 records · Page 3Linked to original sources
PubMed1985

Cricopharyngeal myotomy: a review of surgical results in patients with cricopharyngeal achalasia of neurogenic origin.

Cricopharyngeal myotomy is an effective procedure for the treatment of swallowing disorders due to dysfunction of the upper esophageal sphincter and pharyngeal musculature. Eight patients with documented pharyngeal and sphincteric dysfunction have undergone myotomies with significant improvement in swallowing associated with restoration of oral feeding without aspiration in 5, while 3 patients have not improved. The preoperative work-up and evaluation is discussed as well as criteria that may identify those patients most likely to benefit from this treatment.

Aged↗
PubMed1984

Thrombotic microangiopathy and renal failure associated with antineoplastic chemotherapy.

Five patients with carcinoma developed thrombotic microangiopathy (characterized by renal insufficiency, microangiopathic hemolytic anemia, and usually thrombocytopenia) after treatment with cisplatin, bleomycin, and a vinca alkaloid. One patient had thrombotic thrombocytopenic purpura, three the hemolytic-uremic syndrome, and one an apparent forme fruste of one of these disorders. Histologic examination of the renal tissue showed evidence of intravascular coagulation, primarily affecting the small arteries, arterioles, and glomeruli. Because each patient was tumor-free or had only a small tumor at the onset of this syndrome, the thrombotic microangiopathy may have been induced by chemotherapy. Diagnosis of this potentially fatal complication may be delayed or missed if renal tissue or the peripheral blood smear is not examined, because renal failure may be ascribed to cisplatin nephrotoxicity and the anemia and thrombocytopenia to drug-induced bone marrow suppression.

Adult↗
PubMed1984

Effects of 12-O-tetradecanoylphorbol-13-acetate on carcinogenesis in the heterotopically transplanted rat urinary bladder.

12-O-Tetradecanoylphorbol-13-acetate (TPA), a potent promoter of mouse skin carcinogenesis, was tested for possible tumor-enhancing effects on urinary bladder carcinogenesis using the heterotopically transplanted bladder (HTB) model. Weekly administration of TPA at 1.0 microgram/week to N-methyl-N-nitrosourea-initiated HTBs did not increase tumor incidence, but instead, resulted in a significantly high incidence of nodulopapillary hyperplasia, an early neoplastic lesion, suggesting possible tumor enhancement by TPA. In addition, administration of a high dose of TPA with or without a carcinogen treatment led to the development of numerous finger-like epithelial projections on the luminal surface of the HTBs. Evidence indicates that epithelial projections are formed as a result of proliferation of intermediate cells. Whether these structures evolve into true neoplastic lesions is at present unknown.

Animals↗
PubMed1983

Effect of a collagen substrate on the growth and development of normal and tumorigenic rat urothelial cells.

The growth and morphology of 4 tumorigenic rat urothelial cell lines grown on collagen-coated nylon discs was characterized and compared to normal cells. In contrast to cells cultured on a plastic substrate with or without a thin "nonporous" collagen coating, tumor cells grown on porous collagen-coated nylon discs: 1) grew to greater protein densities; 2) formed tissue structures characteristic for the type of tumor they developed upon back-transplantation; and 3) could be grown and cultured indefinitely without subculturing. Thus, similarly to normal urothelial stratification and differentiation in vitro, tumorigenic cells apparently require a "porous" collagen substrate to allow differentiation analogous to that observed in vivo.

Animals↗
PubMed1982

Melanin-containing peripheral carcinoid of the lung.

A case report of a patient with peripheral bronchial carcinoid is presented. The tumor cells contained characteristic neurosecretory granules, filopodia and microvilli. Some cells contained both neurosecretory granules and the granular variant of melanosome. We suggest that the demonstration of melanosomes does not necessarily confirm the diagnosis of melanoma and that melanin be added to the long list of substances contained in carcinoid tumors.

Carcinoid Tumor↗
PubMed1982

Characteristics of peripheral blood monocytes in hereditary xerocytosis and spherocytosis.

Peripheral blood monocytes isolated from patients with congenital hemolytic anemia, hereditary xerocytosis and spherocytosis, demonstrated in vivo engulfment of red cell and platelet fragments. In addition, morphometric studies performed on these monocytes showed an increase in cytoplasmic/nuclear ratio as well as lysosome and phagosome volumes. The production of carbon dioxide from glucose-1-14C in abnormal monocytes was increased (15-80%) but the intracellular values of beta-glucuronidase and esterase activity were similar to control monocytes. Monocyte locomotion assessed in the presence of chemotactic stimuli was found significantly increased (73 +/- 12 monocytes/oil immersion fields vs. 46 +/- 5 for control monocytes). We concluded that the monocytes in hemolytic anemias associated with increased in vitro red cell fragmentation have some features resembling the 'stimulated' monocytes and that this alteration may be due to red blood cell fragment ingestion.

Anemia, Hemolytic, Congenital↗
PubMed1982

Ultrastructural changes in surface topography, glycocalyx and plasma membrane interior of tumor cells during exocytosis of mucus.

Plasma membrane changes, which occur during exocytosis, were studied by electron microscopy in six specimens of primary mucous-producing adenocarcinoma of human urinary bladder. The luminal surfaces of non-secretory neoplastic cells display numerous microvilli, which have a thick ruthenium red-positive glycocalyx. Neoplastic secretory cells have a smooth luminal surface with relatively few microvilli. The glycocalyces of these cells are thin, especially at locations where the plasmalemma and underlying mucous granule membrane are in close apposition. The fused membranes often bulge into the lumen forming distinct protuberances. In freeze-fracture replicas the protuberances appear devoid of 7-8 nm intramembrane particles. Our results suggest that there are differences between non-secretory and secretory neoplastic cells that are expressed in surface topography, glycocalyx and internal membrane structure. Secretion-induced changes observed in plasma membranes of the neoplastic cells closely resemble changes that are known to occur in the plasmalemma of normal secretory cells.

Adenocarcinoma↗
PubMed1981

Scanning electron microscopic features of human urinary bladder cancer.

Biopsies from 17 cases of transitional cell carcinoma of the urinary bladder were examined by scanning electron microscopy to evaluate surface features of the luminal cells. Pleomorphic microvilli were observed on cells in all cases regardless of tumor grade. Several types of cell surface patterns were observed but variability in appearance increased with grade as did the degree of pleomorphism of the microvilli. Pleomorphic microvilli were not observed in biopsies from two patients without bladder lesions.

Biopsy↗
PubMed1981

Primary adenocarcinomas of the human urinary bladder: histochemical, immunological and ultrastructural studies.

Neoplastic and non-neoplastic tissue specimens from ten patients with primary adenocarcinoma of the urinary bladder were examined. Most of these tumors were associated with either foci of transitional cell carcinoma and/or with glandular metaplasia of the bladder epithelium. The mucin produced by the neoplastic cells was PAS, alcian blue, mucicarmine, PB/KOH/PAS, and RPB/KOH/PAS-positive. ABH isoantigens of these tumors were not always deleted. Ultrastructurally, the neoplastic cells resembled goblet cells. Their plasma membrane had numerous microvilli with prominent glycocalyx. Proliferation and attenuation of tight junctions were noted. The gap junctions were few and small. Two types of desmosomes were found. The ultrastructural features of the neoplastic cells were attributed in part to the malignant transformation and in part to the direction of their differentiation. We have not observed any distinctive morphologic, histochemical, immunologic or ultrastructural features that might be diagnostic for these adenocarcinomas.

Adenocarcinoma↗
PubMed1981

Scanning electron microscopic examination of reversible hyperplasia of the rat urinary bladder.

Urinary bladder damage caused by surgical incision, freeze-ulceration, or formalin instillation in male Fischer 344 rats was studied by light and scanning electron microscopy. The first two methods resulted in focal ulceration of the urinary bladder; the last induced diffuse mucosal damage. With each method, the damage was followed by regenerative hyperplasia and repair, the bladder mucosa returning to normal in 3-4 weeks. Epithelial cells in the hyperplastic areas had ropy microridges and uniform short microvilli on their luminal surfaces as observed by scanning electron microscopy. When the hyperplasia was marked, with nodular and papillary formation, occasional epithelial cells had pleomorphic microvilli on their surfaces. Rats treated either by surgical incision or freeze-ulceration had normal bladders after a 2-year observation period. Combined with results from previous experiments, pleomorphic microvilli are not a marker of neoplasia or irreversibility but appear with marked or prolonged mucosal proliferation even if reversible.

Animals↗
PubMed1981

Effect of L-tryptophan and sodium saccharin on urinary tract carcinogenesis initiated by N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide.

The effect of sodium saccharin (SAC) or L-tryptophan (LT) on urinary bladder carcinogenesis initiated by feeding N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide (FANFT) for 4 weeks as 0.2% of the diet to male F344 weanling rats was evaluated. SAC was fed as 5% of the diet, and LT was 2% of the diet. FANFT fed for 4 weeks followed by 100 weeks of control diet did not produce any carcinomas; one of 25 rats developed a bladder papilloma. Of 26 rats fed SAC for 100 weeks after FANFT, two developed papillomas, and five developed carcinomas (p less than 0.03). Of 26 rats fed LT for 100 weeks after FANFT, three developed papillomas, and two developed carcinomas (p greater than 0.1) Eight rats fed FANFT for 72 weeks all developed bladder carcinomas, but rats fed control diet alone, control diet with SAC, or control diet with LT did not develop any bladder tumors. Scanning electron microscopic examination of Week 104 of the experiment showed the presence of pleomorphic microvilli on the bladder surface of some rats fed SAC of LT whether following 4 weeks of control diet alone or 4 weeks of FANFT. Four weeks of FANFT feeding, a lower dose than used previously in our studies, appears to be a subcarcinogenic level. Under these experimental conditions, the promoting activity of SAC is demonstrated with statistical significance. The results with LT were not statistically significant.

Animals↗
PubMed1981

Scanning electron microscopy of cyclophosphamide-induced hyperplasia of the rat urinary bladder.

Urinary bladder damage caused by cyclophosphamide in male F344 rats was studied by light microscopy, scanning electron microscopy, and autoradiography. Cyclophosphamide was injected intraperitoneally at doses of 50, 75, 100, 150, and 200 mg. per kg. of body weight, and rats were killed at several intervals following treatment. Extensive necrosis of the bladder was followed by regenerative hyperplasia of the epithelium. A dose response was evident in the number and size of lesions induced and the time of regeneration and repair. Scanning electron microscopy disclosed pleomorphic microvilli on the luminal surface of cells during the early phases of hyperplasia. The greatest number of cells with pleomorphic microvilli occurred 2, 5 and 7 to 8 days following injection of 75, 100, and 200 mg. per kg. of cyclophosphamide, respectively. The hyperplastic lesions also had cells with short, uniform microvilli and ropy or leafy microridges on their surfaces. Autoradiographs of the urinary bladders showed marked labeling of epithelial cells in the early phase of hyperplasia. Of the few rats surviving beyond 1 year after a single injection, none had bladder lesions at any of the dose levels. The changes in the epithelium observed by scanning electron microscopy following cyclophosphamide injection were compared to those observed during bladder carcinogenesis.

Animals↗