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Biomedical subjects

D R Hinton

Publications and source records attributed to D R Hinton.

166 records · Page 10Linked to original sources
PubMedDate not supplied

The value of histopathological examination of surgically removed blood clot in determining the etiology of spontaneous intracerebral hemorrhage.

The surgical specimens from all evacuated spontaneous intracerebral and intracerebellar hemorrhages at the Toronto General Hospital from 1976 to 1981 were reviewed. Cases resulting from trauma or from pre-operatively diagnosed aneurysms or arteriovenous malformations were excluded, leaving 84 cases in which the etiology was unknown. Seventy-five of the cases were intracerebral hemorrhages, while 6 were intracerebellar and 3 were intraventricular. Brain tissue was received with the blood clot in 54 cases (64%). From this tissue, an anatomic diagnosis was made in 37 cases; and in 14, the specific etiology of the hemorrhage could be determined. The specific etiologic diagnoses were tumor (7), amyloid angiopathy (6) and abscess (1). In 4 other cases, vasculopathy associated with hypertension was suggested as a possible etiologic diagnosis. The high incidence of a specific etiologic diagnosis made from specimens in which tissue was included (25%) suggests that biopsy of adjacent brain tissue or preservation of tissue fragments identified at the time of surgery is of diagnostic value.

Adult↗
PubMedDate not supplied

Pituitary adenomas. Correlation of the cytologic appearance with biologic behavior.

OBJECTIVE: To determine the extent of nuclear pleomorphism in pituitary adenomas and the relationship of these cytologic changes to clinical features, endocrine evaluations and proliferative potential. STUDY DESIGN: The study group consisted of 93 sequential patients with pituitary adenomas in which smear and touch preparations were performed. Nuclear pleomorphism was assessed semiquantitatively and compared to immunohistochemical analyses of pituitary hormones on formalin-fixed paraffin sections, endocrine evaluations, clinical observations and proliferative potential as determined by immunoreactivity to Ki-67 on frozen sections. RESULTS: Varying degrees of nuclear pleomorphism were observed in 66/93 tumors. However, these changes were more pronounced in clinically functioning (growth hormone, prolactin or ACTH), as compared to nonfunctioning, tumors (P < .01). Pleomorphism did not correlate with macroscopic invasiveness. The pituitary adenomas that showed pleomorphism had significantly higher Ki-67 indices than did those without nuclear changes (P < .02). Significantly higher Ki-67 expression was also found in clinically functioning tumors when compared to nonfunctioning tumors (P < .03). CONCLUSION: Significant nuclear pleomorphism is common in functional pituitary adenomas of several types but does not correlate with more aggressive behavior.

Adenoma↗
PubMedDate not supplied

Interaction of immune and central nervous systems: contribution of anti-viral Thy-1+ cells to demyelination induced by coronavirus JHM.

The murine coronavirus JHM (JHMV or MHV-4) has been intensively studied as an experimental model of viral-induced demyelination; nonetheless, the degree to which demyelination results from direct viral cytolysis of oligodendroglia or immunological mechanisms remains controversial. To examine the contribution of immunity to the pathogenesis of JHMV in the central nervous system (CNS), mice were exposed to immunosuppressive doses of x-irradiation 3 days post infection and observed for clinical and pathological evidence of acute and subacute demyelination. Irradiated mice were found to have a nearly thousand-fold increase in central nervous system virus titer, as well as the presence of both abundant virus and viral antigen in white matter cells with the morphological characteristics of oligodendrocytes. Nonetheless, infected, irradiated mice had little or no evidence of demyelination or destruction of CNS cells. Adoptive transfers of spleen cells from syngeneic JHMV-immunized donors into irradiated JHMV-infected mice were carried out in order to determine the effect of immune reconstitution on pathogenesis. Splenocytes from JHMV-immune donors, but not naive donors or donors immunized with irrelevant antigen, completely restored demyelination in irradiated, JHMV-infected recipients. Depletion of Thy-1+ cells by treatment with monoclonal antibody and complement abolished the ability to transfer demyelination. We conclude that: 1) JHMV infection of the CNS does not result in acute or subacute demyelination in the absence of an intact immune response, and 2) viral-specific Thy-1+ cells are an essential element in the induction of demyelinating CNS lesions that result from JHMV infection.

Animals↗