Biomedical subjects
Publications and source records attributed to J Raisanen.
Sections of the cerebrum, cerebellum, and brain stem of a rugby player who died 15 hours after being tackled were stained using an immunoperoxidase technique to detect beta-amyloid protein. The sections of the pons showed axonal spheroids in the base, and those of the cerebellum showed axonal spheroids in deep white matter. The findings demonstrated axonal injury following a fall from the victim's height in a team sporting event.
OBJECTIVE: Vertebral artery compression causing brainstem ischemia has been suggested to underlie the sudden infant death syndrome. Vertebral artery distortion from neck movements has been demonstrated by angiography in infants, but direct evidence for arterial compression is lacking. In an attempt to demonstrate vertebral artery compression from head movement, we examined at postmortem the vertebral arteries of infants after neck extension or rotation. METHODS: The C1-C7 spinal column, together with a 2-cm rim of skull base, was removed from 20 infants dying from sudden infant death syndrome or other causes. In 5 cases the neck was extended, in 9 cases it was rotated 90 degrees to the right, and in 6 cases the neck was held in the neutral position. The neck was maintained in these positions during formalin fixation, and serial sections of selected blocks were examined microscopically. RESULTS: In 3 of 5 extended cases, bilateral vertebral artery compression was seen between the occipital bone and C1. In 3 of 9 rotated cases, the left vertebral artery was compressed adjacent to C1 before the artery entered the transverse foramen. No vertebral artery compression was seen in the necks held in the neutral position. CONCLUSIONS: The vertebral arteries of some infants can be compressed by neck movement. This could induce lethal brainstem ischemia in infants with inadequate collateral blood flow or with poor compensatory arterial dilatation, and may underlie some cases of sudden infant death syndrome.
OBJECTIVE: To determine the prevalence of the Wernicke-Korsakoff syndrome (WKS) in Australia and compare this with previous studies. DESIGN AND SETTING: Prospective autopsy study at the New South Wales Institute of Forensic Medicine, 1996-1997. METHODS: Brains of deceased people (aged over 15 years) derived from 2212 sequential autopsies performed between 1 January 1996 and 31 December 1997 were studied macroscopically and microscopically to identify cases of WKS. MAIN OUTCOME MEASURES: Standard histological criteria for WKS and any available clinical data. RESULTS: Twenty-five cases of WKS were identified (prevalence, 1.1%), mostly among the 5.9% of the 2212 people who had a history suggestive of alcohol abuse. Only four cases (16%) had been diagnosed during life. CONCLUSIONS: There has been a significant reduction in the prevalence of WKS in Australia since the introduction of thiamine enrichment of bread flour. While the prevalence is still higher than in most other Western countries, further research is needed before adding thiamine to alcoholic beverages can be recommended.
BACKGROUND: Although cytomegalovirus (CMV) infection of the retina and brain is common in patients with acquired immunodeficiency syndrome (AIDS), it is exceedingly rare in patients with immunodeficiencies due to other causes. This is the first report on ocular and cerebral histopathology of disseminated CMV in a child with severe combined immunodeficiency syndrome (SCID). METHODS: The authors examined by routine histopathologic methods the eyes of a 2-year-old white boy with SCID and bilateral CMV retinitis who died after failure of a third attempt at allogeneic bone marrow transplantation (BMT). RESULTS: Cytomegalovirus inclusions were found in the necrotic retinal remnants, in the hyperplastic and scarred retinal pigment epithelium, and bilaterally in the optic nerves. There were infiltrates of macrophages in response to the infection or the infused silicon, but no lymphoid infiltrates. Cytomegalovirus inclusions also were found in brain tissue. CONCLUSION: The histologic features resembled those of CMV retinitis and optic neuritis in AIDS.
A preterm infant's immature brain is susceptible to both anoxic and hemorrhagic injury during periods of physiological stress. The advent of in utero surgery has created a new population of premature patients at risk for central nervous system (CNS) injury. The aim of this study was to evaluate the frequency and nature of CNS injuries in fetal surgical patients. Of 33 fetuses with known neurological outcome after fetal surgery, CNS injuries were identified in seven (21%). Of the seven, four had significant episodes of fetal bradycardia (3) or neonatal hypotension (1), which suggests that asphyxia contributed to the neurological injury. The CNS injuries in the other three patients occurred unexpectedly and without associated signs of fetal distress. The authors speculate that these injuries may have been caused by sudden fluxes in cerebral blood flow, induced by maternal hypoxia (1) or by maternally administered tocolytic drugs (2) used to treat postoperative preterm labor.
Pituitary adenomas are common tumors that account for about 10% of intracranial neoplasms. Most arise from the adenohypophysis and are confined to the region of the sella turcica. Other sites may be involved as a result of extension, infiltration, or ectopic location. However, posterior extension or ectopic involvement of the clivus of the sphenoid and occipital bones is rare. Seven patients with destructive clival masses were referred to our institution with presumptive diagnoses of chordomas. In all cases, histologic workup revealed pituitary adenomas. Because they represent a subset of adenomas, the histologic features of the tumors were studied, and the clinical histories of the patients were reviewed. Five of the patients were men, aged 31 to 67 years, and two were women, aged 55 and 67 years. Four patients had extremely high plasma concentrations of prolactin (8,132-22,424 ng/ml, nl < 15). Four tumors resembled usual sellar adenomas; however, three exhibited nuclear pleomorphism, mitotic figures, and other morphologic features, suggesting alternate diagnoses. Three required immunoperoxidase stains in addition to those for pituitary hormones, and three required electron microscopy for diagnosis. Destructive invasion of the clivus by pituitary adenomas is rare, and anaplastic features of some of the tumors may lead to difficult diagnoses.
The authors report an unusual case of a myxopapillary ependymoma arising from the lateral ventricle. The patient, a 37-year-old woman, developed recurrent symptoms including scotomata, disorientation, and headache during two successive pregnancies before the definitive diagnosis. The causes of this ependymoma variant and its relationship to pregnancy are discussed.
A rare case of intradural chordoma is described. The literature contains seven examples of intradural extraosseous chordoma, all reported in a ventral location. This is the first reported case of a primary intradural chordoma distant from the clivus and involving both the supra- and infratentorial compartments.
A one year old boy was found to have a large tumor encompassing the pineal region and extending towards the third and lateral ventricles and quadrigeminal plate. The tumor was composed mostly of small, undifferentiated cells. Some small cells were arranged in Flexner-Wintersteiner rosettes and a few displayed fleurettes. The tumor contained immature cartilage and skeletal muscle and numerous clusters of pigmented epithelial-like cells which, histologically, resembled those found in melanotic neuroectodermal tumors of infancy (retinal anlage tumors) and retinal or ciliary epithelium. Immunologic stains demonstrated neurofilaments synaptophysin and retinal S-antigen in some of the small cells and transthyretin in some of the epithelial-like cells. The findings indicate that certain primary pineal parenchymal tumors have features in common with tumors of the ocular medullary epithelium.
Hypertensive crises have been provoked in pheochromocytoma patients by the injection of contrast media during angiography and venography. Fear of similar reactions to intravenous urographic contrast medium injection during computed tomography has led to studies without contrast enhancement when pheochromocytoma is suspected. With extraadrenal pheochromocytomas, intravenous contrast enhancement may be essential for tumor location by computed tomography. The catecholamine responses to injection of urographic contrast medium were examined in eight patients with pheochromocytoma and in 12 undergoing computed tomography for other reasons. Plasma norepinephrine concentrations fell in nonpheochromocytoma patients (p less than 0.005), while in pheochromocytoma patients the response was unpredictable, rising in six individuals, although the mean response was not significant (p greater than 0.35). In five patients the magnitude of the increase in norepinephrine concentrations was large enough to have led to a pressor effect had alpha adrenergic blockade not been used. It was concluded that intravenous urographic contrast medium may elevate plasma catecholamines in a significant proportion of patients with pheochromocytoma, but that with adequate alpha adrenergic blockade this should pose no threat.
PIII and b-wave spectral sensitivity functions were measured under various adapted conditions in the 13-lined ground squirrel. The PIII was isolated by intravitreal injection of sodium L-aspartate. Under the conditions studied, the PIII spectral sensitivity function always fitted the absorption spectrum of a 518 +/- 3 mm Dartnall nomogram. This suggests that of the three photoreceptors ('rod-like', 'blue' cone and 'green' cone) present in the 13-lined ground squirrel the green cones are the overwhelming majority. The dark-adapted b-wave had two components; a b1-wave with a spectral sensitivity that fitted a 516 +/- 1 nm Dartnall nomogram and a b2-wave with a spectral sensitivity that fitted a 502 +/- 4 nm Dartnall nomogram. The light-adapted b-wave had a spectral sensitivity that fitted a 516 +/- 2 nm Dartnall nomogram.
OBJECTIVE: To determine the usefulness of cytology in the intraoperative diagnosis of central demyelinating disorders. STUDY DESIGN: Smears of three multiple sclerosis (MS) plaques and two progressive multifocal leukoencephalopathy (PML) lesions prepared intraoperatively were examined and compared. The cytologic features were contrasted with those of infiltrating astrocytomas. RESULTS: The preparations of demyelinating lesions revealed normal or reactive astrocytes and large numbers of foamy macrophages, the key diagnostic finding. The preparations of the lesions of PML contained virally infected oligodendrocytes. The specific cell types were identified easily because cytoplasmic margins could be distinguished. CONCLUSION: Cytologic preparations of lesions of PML and MS permitted rapid identification of the diagnostic features and distinguished them from infiltrating astrocytomas, the most important lesion in the differential diagnosis. The findings demonstrated the utility of cytology in the diagnosis of central demyelinating diseases.