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Biomedical subjects

H V Vinters

Publications and source records attributed to H V Vinters.

At least 217 records · Page 12Linked to original sources
PubMed1985

The histotoxicity of cyanoacrylates. A selective review.

Cyanoacrylates, a group of rapidly polymerizing adhesives, have found widespread uses in oral and general surgery as well as surgical subspecialties, for example as hemostatic and anastomotic agents. They have been utilized most recently as materials for embolotherapy of complex cerebral and extra-cerebral vascular anomalies. The histopathology that results from their deposition in human tissues is thus an important consideration, and the subject of this review. Particular attention is given to the fate of cyanoacrylates in cerebral lesions after iatrogenic embolization procedures. The apparent toxicity of these plastics on blood vessel walls is discussed in relation to experimental observations. It is imperative that clinicians who use this group of substances evaluate their potential functions in the light of the pathologic findings.

Animals↗
PubMed1985

Central pontine myelinolysis in a child with the Shwachman-Diamond syndrome.

The first case of central pontine myelinolysis in a child with the Shwachman-Diamond syndrome is reported. Marked fluctuation of serum glucose and sodium levels, but no hyponatremia, was observed throughout the patient's hospital course. Both of these abnormalities may have contributed to the development of the lesion. Liver abnormalities, implicated in other pediatric cases of central pontine myelinolysis, were also observed.

Anemia↗
PubMed1985

Uptake of glucose analogues into cultured cerebral microvessel endothelium.

Tritiated glucose analogues 3-O-methylglucose (3-OMG) and 2-deoxyglucose (2-DG) were used to study glucose uptake properties in established lines of cultured mouse cerebral microvessel endothelium. Uptake of both analogues was similar in terms of rate and absolute amount for the first two minutes. Thereafter, intracellular accumulation of 2-DG continued at a more rapid rate because of intracellular phosphorylation of this substrate. The uptake of 3-OMG uptake was temperature-dependent, independent of Na+, and not inhibited by ouabain or 2,4-dinitrophenol. Phloretin and cytochalasin B both significantly inhibited 3-OMG uptake. Other hexoses in high concentration acted as competitive inhibitors at the endothelial cell membrane. Pre-incubation of cells with 50 mM D-glucose resulted in higher levels of 3-OMG accumulation than in control cells (counter-transport phenomenon). In contrast to findings at the blood-brain barrier in vivo, insulin was found to stimulate 3-OMG uptake. Maximal stimulation of approximately 3-fold was found at ambient insulin concentrations of 1,000 ng/ml or higher. The findings provide support at the cellular level for some components of the model of carrier-mediated glucose transport across the blood-brain barrier which has been postulated to exist in vivo. The effect of insulin is discussed in the light of new data that show stimulation of glucose analogue transport into isolated cerebral capillaries.

3-O-Methylglucose↗
PubMed1985

Insulin stimulates DNA synthesis in cerebral microvessel endothelium and smooth muscle.

Experiments were performed to test the hypothesis that insulin stimulates DNA synthesis in cerebral microvessel endothelium and smooth muscle. Cultured endothelium and smooth muscle derived from isolated mouse cerebral microvessels were exposed to insulin in serum-free medium, and [3H]-thymidine incorporation in the cells was measured. Up to 40-fold stimulation of DNA synthesis in endothelium and fourfold stimulation in smooth muscle were observed. Stimulation became maximal in both cell types at an insulin concentration of approximately 10(4) ng/ml, although an effect was observed at much lower concentrations. Similar concentrations of insulin produced a less-dramatic (approximately twofold) increase in both endothelial and smooth muscle cell numbers. This effect of insulin, observed in microvessel endothelium and smooth muscle, but not in bovine aortic endothelium, emphasizes another way in which large- and small-vessel endothelia appear to differ.

Animals↗
PubMed1985

Staining procedure to aid in assessment of bucrylate histotoxicity in tissue sections.

Isobutyl-2-cyanoacrylate (bucrylate) is commonly used as a material for therapeutic embolization. Histologic sections of embolized tissue routinely stained with hematoxylin-eosin show the bucrylate as a translucent material. We outline a staining procedure that demonstrates bucrylate in tissue sections. It is useful in routinely prepared paraffin-embedded tissue, and it is also effective after embolized tissues have been processed with petroleum ether rather than xylene. This stain may be effectively utilized to assess harmful tissue reactions to bucrylate.

Arteriovenous Malformations↗
PubMed1985

Cerebellar pathology in ataxia-telangiectasia: the significance of basket cells.

The unique neuropathology of AT is discussed, focusing on changes in the cerebellum--site of the most consistent and severe findings. In the cerebellum, despite marked Purkinje cell and granule cell loss and thinning of the molecular layer, the basket cells are relatively preserved, as demonstrated by the Bielschowsky staining. To document that basket cells do, indeed, represent a "footprint" of where Purkinje cells once existed, we examined the cerebellum of patients with chronic alcohol abuse. We again found normal numbers of "empty" basket cells. This suggests that AT is a degenerative condition in which the Purkinje cell layer forms, perhaps abnormally, but then undergoes neuronal depletion.

Alcoholism↗
PubMed1985

Sequence of cellular events in cerebellar ontogeny relevant to expression of neuronal abnormalities in ataxia-telangiectasia.

An attempt was made to relate expression of neuronal abnormalities in ataxia-telangiectasia (AT) to the sequence of normal cellular events in the developing human cerebellum. Previous light and electron microscopic analyses indicate that the cerebellar cortex in humans develops during a protracted period that spans 8 fetal and 12 postnatal months. However, the Purkinje cells that comprise the most obvious lesion in the AT disorder are all generated before the end of the fourth fetal month. Correlative Golgi studies in human and [3H]thymidine labeling of DNA in dividing cerebellar cells in rhesus monkey demonstrate that after the last mitotic division Purkinje cells migrate to the cortical plate where they form a well-defined stratum below the embryonic molecular layer. Only thereafter do they begin to differentiate and develop their large dendritic tree. The dendrites grow in coordination and simultaneously with the genesis of parallel fibers in the molecular layer. The parallel fibers--the horizontal portion of granule cell axons--form between the fourth fetal and twelfth postnatal month in a well-defined inside-outside order, the earliest generated fibers being situated near the Purkinje cell layer and the last fibers generated lying closer to the pial surface. The four cases of AT examined in this study showed the usual neuropathological changes, which include a variable degree of Purkinje and granule cell loss. However, we emphasize here an abnormality of dendritic arborization and the presence of displaced Purkinje cells, which are situated in the middle and superficial strata of the molecular layer. Based on the sequence of histogenetic events, we argue that neither abnormal arborization nor aberrant position could be attained after parallel fibers of the deeper strata have been laid down and after Purkinje cells have formed their dendritic tree. Therefore, we suggest that the AT disorder in these cases must affect Purkinje cell differentiation or the interaction of these cells with parallel fibers during the first half of gestation, which is considerably earlier than any other recognized expression of the disorder. The subsequent degeneration of Purkinje cells is apparently not related to the aberrant position of the somas, since many Purkinje cells situated in normal position also die and there is no evidence that displaced cells degenerate at a slower or more rapid rate. The early expression of AT in the central nervous system provides new insight into possible pathogenesis and opens new avenues for research.

Ataxia Telangiectasia↗
PubMed1984

Hydrocephalus with cerebral aqueductal dysgenesis and craniofacial anomalies.

A pre-term infant was born with multiple limb and craniofacial anomalies, including craniosynostosis and a nasopharyngeal adenohypophysis. Severe hydrocephalus of the lateral and third ventricles was attributed to cerebral aqueductal dysgenesis. Scattered aqueductules and ependymal rosettes were found throughout the midbrain and pontine tegmentum. An hypothesis to explain the unique constellation of craniocerebral findings is discussed.

Abnormalities, Multiple↗
PubMed1984

Spontaneous spongy degeneration of the mouse brain.

A spontaneously-occurring spongy disorder of the white matter of the central nervous system was discovered in the Charles River strain of Swiss-Webster mice and is described in this report. The disorder was transmitted with an autosomal recessive pattern of inheritance. Clinical characteristics of the affected animals included enlargement of the cranium, failure to thrive and tremor of the hind limbs when held by the tail in a suspended position. Maintenance of the colony with propagation of the disease was achieved by selective in-breeding of litter mates. Light microscopic examination of the central nervous system revealed a spongy degeneration of the white matter of the entire neuraxis. Ultrastructural studies localized the abnormality to the cell body and processes of the astrocyte which appeared distended and enlarged with dispersion of cytoplasmic organelles. Hemidesmosomes were prominent in the foot processes of astrocytes. This animal model bears a similar morphology and pattern of inheritance to Canavan's spongy degeneration of the white matter in humans and should provide a base for future investigations aimed at gaining insight into the pathogenesis of the human and this animal neurological disorder.

Animals↗
PubMed1984

Glial cells influence polarity of the blood-brain barrier.

Polarity has been shown to exist at the blood-brain barrier (BBB) with respect to Na+-dependent neutral amino acid transport. A situation similar to the endothelial-astrocyte relationship existing at the BBB can be produced by growing cultured cerebral endothelium on one side of a filter and C6 glial cells on the other in an enclosed double chamber. In this setting 3H-alpha-methylaminoisobutyric acid transport can be demonstrated and is more rapid from the glial surface across the endothelium, as compared with transport in the opposite direction. The observation supports a glial influence on BBB polarity in this system.

Aminoisobutyric Acids↗
PubMed1983

Uptake of adenosine into cultured cerebral endothelium.

Adenosine uptake by cultured cerebral endothelium is a carrier-mediated process. The Km value for adenosine uptake is 5.0 microM and the vmax is 1.15 nmol/min/mg cell protein. The uptake system is inhibited by the adenosine analog 2-chloroadenosine at low adenosine concentrations. The results prove the existence of a nucleoside transport system associated with cerebral capillary endothelium.

2-Chloroadenosine↗
PubMed1983

'Foreign' particles in encephalic vascular malformations.

Among 84 surgically resected arteriovenous malformations (AVMs), four were found to have refractile foreign particles lined by endothelium in the vessel walls. In three cases, this was associated with granuloma formation. The particles were probably introduced during cerebral angiography. They represent a not unusual pathologic finding, are relatively more common in AVMs than in other neurosurgically excised lesions, and may have clinical significance, especially if abundant.

Adult↗
PubMed1983

Uptake of adenosine by cultured cerebral vascular smooth muscle cells.

Adenosine uptake by cerebral smooth muscle cells is a carrier-mediated process. The Km value for adenosine uptake is 10.0 microM and the Vmax is 0.95 nmol/min-mg cell protein. This uptake system is inhibited by the adenosine analog 2-chloroadenosine at low adenosine concentrations. These results prove the existence of a nucleoside transport system associated with cerebral smooth muscle.

Adenosine↗
PubMed1981

Neurenteric cysts of the spinal cord mimicking multiple sclerosis.

A 54-year-old man died following a 20-year course of intermittent neurologic symptoms. He carried a diagnosis of multiple sclerosis, with most severe involvement thought to be in the spinal cord. At autopsy, two neurenteric (enterogenous) cysts were found to indent the anterior spinal cord -- at the T4 and T11 cord levels. Partial diplomyelia was present in the lumbo-sacral cord. These findings represent a unique combination of congenital abnormalities. Their embryogenesis and pathogenesis are discussed.

Diagnosis, Differential↗
PubMed1981

Pathology of arteriovenous malformations embolized with isobutyl-2-cyanoacrylate (bucrylate). Report of two cases.

There is controversy as to the possible toxic effects of isobutyl-2-cyanoacrylate (bucrylate) when this substance is used for purposes of therapeutic embolization. Two cases are presented in which cerebral arteriovenous malformations were resected, one 42 days and the other a year after bucrylate embolization. In both, pathological examination revealed a brisk intimal foreign-body giant-cell reaction wherever bucrylate was present in a vessel, along with chronic inflammation in the vessel walls and adjacent brain parenchyma. The findings are discussed in the light of other observations on the histotoxicity of bucrylate.

Adult↗
PubMedDate not supplied

Intraventricular neurocytoma with prominent myelin figures.

A case is reported of intraventricular neurocytoma that had characteristic light microscopic findings of neurocytoma with prominent intracytoplasmic concentric lamellar structures mimicking myelin sheaths. On routine H&E-stained sections, this tumor showed intracytoplasmic vesicular bleb-like structures having eosinophilic cores that were consistent with ultrastructural concentric lamellar structures. Immunohistochemically, this tumor was immunoreactive for synaptophysin and neurofilament, but negative for antibody to glial fibriallary acidic protein. Electron microscopic findings fulfilled the criteria for neurocytoma, with the presence of neurosecretory granules and neurotubules. These findings may suggest dual differentiation of this tumor into neurocytes and oligodendrocytes.

Adolescent↗