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Biomedical subjects

S I Roth

Publications and source records attributed to S I Roth.

At least 55 records · Page 3Linked to original sources
PubMed1989

Reis-Bücklers' corneal dystrophy. Immunofluorescent and electron microscopic studies.

The anterior stroma, epithelium, and Bowman's layer have been proposed as the site of primary pathology in Reis-Bücklers' corneal dystrophy (RBCD). Immunofluorescent localization of laminin and bullous pemphigoid antigen (BPA) was compared with the ultrastructure of RBCD. As previously reported, patchy deposition of characteristic "peculiar curly" filaments was found in the supra-Bowman's, subepithelial fibrous tissue. We also recognized areas of early involvement with deposition of this "peculiar curly" material between a distorted epithelial basal lamina and a normal undisturbed Bowman's layer. In normal cornea, laminin and BPA localized to the epithelial basal lamina. In RBCD, laminin and BPA were in a piebald mosaic distribution throughout the aberrant subepithelial fibrous tissue between the basal lamina and the buried Bowman's layer. This indicates that RBCD is an epithelial disease, with the "peculiar curly" material paralleling the distribution of the attachment proteins.

Aged↗
PubMed1988

Pathogenesis of experimental lipid keratopathy. An ultrastructural study of an animal model system.

The histology and ultrastructure of experimental lipid keratopathy were studied in hypercholesterolemic rabbits in which the insertion of corneal sutures induced vascularization and subsequent lipid deposition in the anterior stroma. Lipid accumulated in the keratocytes, the pericytes and occasionally in the endothelial cells of the capillaries. The lipid-laden keratocytes were concentrated in the region of the capillaries. No lipid was seen in the control rabbits. In the hypercholesterolemic rabbit with sutures, intracellular lipid in the keratocytes was present largely in nonmembrane-limited droplets with smaller amounts of membrane-limited cholesterol crystals and rare numbers of myelin figures. In addition, large, lipid-engorged spherical cells were present. The numerous phagolysosomes seen ultrastructurally suggest that some of these cells probably represent macrophages. Keratocytes and the large, spherical lipid-engorged cells show focal degenerative changes, including pyknotic nuclei, cytoplasmic coagulation and membrane loss, leaving extracellular mixed accumulations of lipid and cytoplasmic organelles. Small numbers of lymphocytes and plasmacytoid cells were present. No corneal lipid was seen in animals with normocholesterolemia, with or without sutures. In hypercholesterolemic animals, a few lipid-laden keratocytes without macrophages were identified even in the absence of vessels. These morphologic studies support the hypothesis that the accumulation of the corneal lipid in this animal model of lipid keratopathy is the result of increased lysosomal uptake of lipid, probably as low density lipoprotein, from the extracellular space by the keratocytes. The rate of metabolism of this lipid is insufficient to clear the cells of the lipid and the subsequent lipid inspissation results in keratocyte death, leading to macrophage accumulation of lipid and free lipid in the stroma.

Animals↗
PubMed1988

Late recurrence (33 years) of a gastric epithelioid stromal tumor (leiomyoblastoma) with low malignant potential.

A recurrence of a gastric epithelioid stromal tumor (leiomyoblastoma) 33 years after incomplete resection and radiation therapy is reported. The original tumor involved the posterior gastric wall and presented with intraperitoneal hemorrhage. A tumor recurrence was found attached to the stomach with invasion through the wall of the splenic flexure of the colon. The histologic features of the tumor had not significantly altered, except for a slight increase in mitotic rate. Neither the original tumor nor the recurrence exhibited smooth-muscle differentiation on ultrastructural or immunohistochemical examination, suggesting an origin from an undifferentiated or primitive mesenchymal cell. The term leiomyoblastoma, although established in the literature, should be reserved for epithelioid tumors in which myoid differentiation can be established. The long interval to recurrence supports the suggestion that all of these tumors have at least a low-grade malignant potential.

Adult↗
PubMed1987

Desquamating endotheliopathy. An incipient iridocorneal endothelial syndrome?

Unilateral, noninfectious, nontraumatic corneal endotheliopathy was noted in a 34-year-old man who had had blurred vision for five years without evidence of iridic disease or glaucoma. Ultrastructural studies demonstrated focal necrosis of the corneal endothelial cells, with desquamation of the cells into the anterior chamber. The corneal endothelium appeared to expand beneath the dying endothelial cells, indicating reendothelialization of the cornea. There was no epithelialization of the endothelium, as evidenced by the lack of keratin production or desmosome formation. Descemet's membrane was thickened with edema, a posterior collagenous layer, and fibrous, long-spacing collagen. These alterations in Descemet's membrane were similar to those described for other corneal dystrophies. It is proposed that this unilateral desquamating endotheliopathy represents an incipient form or a forme fruste of the iridocorneal endothelial syndrome.

Adult↗
PubMed1987

The uptake of horseradish peroxidase by the conjunctival epithelium of the guinea-pig.

It has been suggested that in immediate hypersensitivity of the guinea-pig conjunctiva, induced by the topical application of an antigen, the antigen is selectively taken up by the conjunctiva-associated lymphoid tissue. We tested this hypothesis by applying horseradish peroxidase (HRP) to the guinea-pig conjunctiva and studying its uptake by light- and electron microscopy. As early as 30 min after the application of the HRP, precipitate indicating the presence of HRP could be seen in the epithelial cells in membrane limited granules in the non-lymphoid and lymphoid epithelium. There was no selective uptake of HRP by the lymphoid-associated epithelial cells. We hypothesize that the epithelial cells of the conjunctiva, in contrast to those of the small intestine, phagocytose antigen and transfer it directly to the substantia propria of the conjunctiva for local immunologic processing.

Animals↗
PubMed1987

Endothelial viral inclusions in Fuchs' corneal dystrophy.

A case of Fuchs' corneal dystrophy is presented. The patient, a 70-year-old white woman, had bilateral decreasing vision, especially while reading and driving at night. Clinical features were characteristic of Fuchs' corneal dystrophy. Ultrastructural studies demonstrated findings in Descemet's membrane typical of those previously reported with numerous tactoids of fibrous long-spacing collagen in the posterior collagenous layer and in the guttata. In the endothelial cells were encapsulated ellipsoid viral particles, 400 nm long and 225 nm in diameter. They contained an outer and inner membrane with an electron-dense intervening region and a central dense core. Nucleocapsids were present in the endothelial cells and stromal keratocytes. The authors suggest that the pathogenesis of Fuchs' corneal dystrophy may be endothelial damage, and that in this case, the etiology is a viral infection.

Aged↗
PubMed1987

Pathogenesis of experimental lipid keratopathy: corneal and plasma lipids.

Corneal and plasma lipids were studied in a rabbit model to gain insight into the pathogenesis of secondary lipid keratopathy. Rabbits were divided into four groups in which a high cholesterol diet and corneal suture placement were varied to produce lipid keratopathy. In rabbits with lipid keratopathy, quantitative thin layer chromatography revealed that cholesterol esters comprised most of the deposited lipid, with free cholesterol being deposited as well. The ratio of accumulated cholesterol ester to free cholesterol corresponded closely to the same ratio in hypercholesterolemic plasma total low and very low density lipoprotein (TLDL). Furthermore, gas chromatography showed that the cholesterol ester composition in the corneas with lipid keratopathy resembled that seen in hypercholesterolemic plasma TLDL but was different from the pattern observed in the normal cornea. These studies suggest that the direct source of the deposited cholesterol ester is primarily the plasma TLDL. Since phospholipids and triglycerides did not show a significant increase in the experimental corneas, they are presumably metabolized by the keratocytes after the uptake of TLDL. However, the amount of cholesterol ester carried by the lipoprotein exceeds the capacity of the cell for use and excretion and the lipid accumulates in the cornea.

Animals↗
PubMed1984

The honeybee syndrome - implications of the teratogenicity of mannose in rat-embryo culture.

Lethal effects of D-mannose in the honeybee have been recognized for more than a half a century. We observed another toxic effect of D- mannose during culture of rat embryos from the early head-fold stage to the 26-to-29-somite stage (Days 9-1/2 through 11-1 of gestation). The addition to culture mediums of 1.5 mg of D-mannose per milliliter caused growth retardation and faulty neural-tube closure in approximately two thirds of the embryos. Mannose effects occurred during the first 24 hours of culture and were attended by modes inhibition of the glycolysis that constitutes the principal energy pathway at this stage of development. Adding more glucose to preserve glycolytic flux or increasing atmospheric oxygen to promote oxidative metabolism offset the mannose teratogenesis. Our findings highlight the metabolic vulnerabilities that exist during early organogenesis, before oxidative flexibility is established. They may serve as a model to explain the teratogenicity of many other seemingly unrelated agents that could act by perturbing glycolysis at this vulnerable stage.

Abnormalities, Drug-Induced↗
PubMed1982

Lipid storage myopathy in infantile Pompe's disease.

An infant died at 8 months of age with a history of developmental regression, hypotonia, severe weakness, cardiomegaly, congestive heart failure, and hepatomegaly. A diagnosis of Pompe's disease (glycogenosis type II) was established by muscle biopsy at 5 months of age. Vacuolar myopathy involved muscle fibers of histochemical type I more than type II. Many vacuoles were filled with glycogen. In addition, increased amounts of neutral lipid were demonstrated by oil red O stain, electron microscopy, and quantitative analysis. Acid alpha-1,4-glucosidase activity was demonstrated to be deficient. Biochemical studies failed to determine the cause of the lipid accumulation, but demonstrated a low total concentration of carnitine in the muscle (6.37 nmole/mg of protein), associated with elevated activities of carnitine palmityl-transferase and palmityl-coenzyme A dehydrogenase. Palmityl-coenzyme A synthetase activity was in the normal range.

Carnitine O-Palmitoyltransferase↗
PubMed1982

Hepatic ultrastructure in leprechaunism. Hepatic ultrastructural evidence suggesting a syndrome with defective hepatic glucose release.

Leprechaunism is a congenital syndrome with characteristic habitus and facies, with fasting hypoglycemia and hyperinsulinism. In response to a glucose challenge there is prolonged severe hyperglycemia with an increased hyperinsulinemia. Our studies on such a patient showed a normal response of the serum glucose to glucagon stimulation in the fed state but no response in the postabsorptive state. Ultrastructural studies on the hepatocytes demonstrated that a lack of hepatic glycogen was not responsible for the biochemical features, since there was abundant normal beta-glycogen in both the fed and fasting state, the granules being smaller in the fasted state. We speculate that carbohydrate intolerance in leprechaunism may be due to a relative insulin resistance of cell receptors in the fed state. Reactive hyperinsulinemia persisting into the postabsorptive phase appears to antagonize the usual glycogenolytic response to glucagon during fasting, resulting in hypoglycemia despite the presence of large hepatic glycogen stores.

Child, Preschool↗
PubMed1982

The histopathology of camptomelia (bent limbs). A dyschondrogenesis.

Camptomelia is well established syndrome in which the most prominent osseous feature is bowing of the long bones. Although several patients have died, usually due to respiratory insufficiency caused by defects of the cartilage of the tracheal rings and lower respiratory tract, histologic studies of the bone in camptomelia have led to conflicting conclusions about pathogenesis. A complete autopsy of a neonatal case, including serial sections of the long bones, revealed normal enchondral growth sequences of the epiphyseal plate. In the diaphysis, centering around the angle of the bend, the cylinderization process was markedly abnormal. Extensive new secondary trabeculae formed on the concave (posterior) surface of the bone during resorption on the convex (anterior) surface. A cone of dense new bone formed at the apex at the convex anterior angle of the bend. These findings supported previous suggestions that bone formation and remodeling processes were normal. With the variation of bone involvement in different patients, these features indicate that camptomelia is the result of an abnormality of cartilage anlage formation, probably owing to a transient exogenous teratogen. Camptomelia is the preferred term. Basically, the syndrome is a dyschondrogenesis.

Bone and Bones↗
PubMed1981

Congenital muscle fiber-type disproportion in Krabbe's leukodystrophy.

Progressive spasticity, blindness, loss of skills, and neuropathy developed in a 4.5-month-old boy. When examined at 13 months, galactocerebrosidase and galactosylceramide-beta-galactosidase activities were deficient in leukocytes. Intramuscular nerves and a sural nerve biopsy specimen showed loss of nerve fibers, interstitial fibrosis, and axonal degeneration, rather than the segmental demyelination that predominates in most cases. A muscle biopsy specimen showed congenital muscle fiber-type disproportion (CMFTD). This case confirms a previous report of CMFTD in Krabbe's disease and supports a neurogenic mechanism as the basis for CMFTD.

Child, Preschool↗
PubMed1981

Neonatal myotubular myopathy: neuropathy and failure of postnatal maturation of fetal muscle.

The natural course of the pathologic features in striated muscle was studied in a full-term infant with myotubular myopathy. At 5 days of age a muscle biopsy revealed that more than 90 percent of muscle fibers fulfilled histologic, histochemical and electron microscopic criteria of fetal myotubes. The infant died unexpectedly at 9 months of age from spontaneous rupture of a multifocal cavernous hemangioma of the liver. Postmortem examination revealed that progressive maturation of the fetal muscle had not occurred postnatally, and more than 90 percent of myofibers were still apparent myotubes. This maturational arrest was generalized to all striated muscles. The only changes detected since the neonatal period were hypertrophy of the small population of large fibers, but with minor cytoarchitectural alterations, and loss of the incomplete histochemical differentiation with ATPase stains or dedifferentiation not attributed to postmortem diffusion. Involvement of the gubernaculum testis accounted for the undescended testicles. The brain and spinal cord appeared normal. Evidence of degenerating and regenerating axons in the sciatic nerve suggested that the etiology of this maturational arrest of fetal muscle may be neurogenic.

Aging↗
PubMed1981

Osseous changes and osteosacomas in mice continuously fed diets containing diethylstilbestrol or 17 beta-estradiol.

In a study on the long-term effects of dietary diethylstilbestrol or 17 beta-estradiol on C3H mice, estrogens induced a proliferation of osseous trabeculae and increased the incidence and hastened the development of osteofibrotic areas in the sterna. There were 6 osteosarcomas, 2 having metastases, in 1,242 mice fed dietary estrogens over 360 days, but none in 356 untreated controls. These tumors were reviewed along with 4 early sternal osteosarcomas selected from 17 osteosarcomas (only 1 in a control) found thus in two other ongoing comparable studies. In at least 1 case, and possibly in 2 other early cases, tumors were associated with areas of osteofibrosis, and 1 tumor was probably associated with proliferation of bony trabeculae in the medullary cavity.

Animals↗
PubMed1980

Depression of leucine and isoproterenol induced insulin secretions in the spontaneously diabetic New Zealand white rabbit.

Rabbits were studied from a closed colony of NZW rabbits which exhibits a 19% occurrance of spontaneous diabetes mellitus. Six overtly diabetic rabbits and eight rabbits with normal glucose disposal were tested with intravenous glucose challenge (500 mg/kg), L-leucine administration (125 mg/kg), and 30 minute infusions with isoproterenol (10 microgram/kg/min.). These agents were shown to be ineffective insulin secretogogues in the overtly diabetic group when compared to the highly significant IRI response observed in colony rabbits with normal glucose disposal. The data indicate that the defect in IRI secretion observed in the spontaneously diabetic NZW rabbits is not confined to stimulation by glucose, but represents an abnormal IRI release mechanism which appears to lack secretogogue specificity.

Animals↗
PubMed1980

The ultracytochemical localization of cytidine-5'-monophosphatase in normal human thyroid follicle cells.

The properties and distribution of an enzyme specifically hydrolyzing cytidine-5'-monophosphate and the possible relationship of the enzyme to the synthesis and secretion of thyroid hormone in man were investigated using cytochemical methods. Activity due to cytidine-5'-monophosphatase was separated from that due to acid or alkaline phosphatase, both of which are also capable of hydrolyzing cytidine-5'-monophosphate. This distinction was established on the basis of manganese ion stimulation and differences in localization, levels of activity, and pH optimums. The localization of the enzyme along the face of Golgi apparatus involved in the formation of thyroglobulin suggests an association of the enzyme with the glycosylation of thyroglobulin.

Golgi Apparatus↗