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Biomedical subjects

C L White

Publications and source records attributed to C L White.

At least 127 records · Page 7Linked to original sources
PubMed1985

Neuronal pathology in the nucleus basalis and associated cell groups in senile dementia of the Alzheimer's type: possible role in cell loss.

The loss of cortical cholinergic innervation in senile dementia of the Alzheimer's type (SDAT) is associated with cell loss in the nucleus basalis and related cell groups (magnocellular basal nucleus, MBN). We examined MBN in Nissl-, acetylcholinesterase- and thioflavin S-stained sections in two cases of SDAT and in four control brains. Using these sensitive methods, senile plaques were easily demonstrated in MBN, and most MBN neurons showed neurofibrillary degeneration as an early change. Cell loss appeared to be due to maturation of neurofibrillary tangles, displacing normal cellular contents. In contrast to theories that the cell loss in MBN represents retrograde degeneration due to axonal injury in the cerebral cortex, MBN neuronal perikarya may be involved by the same primary processes as cortical neurons.

Acetylcholinesterase↗
PubMed1984

Factor VIII related antigen and glial fibrillary acidic protein immunoreactivity in the differential diagnosis of central nervous system hemangioblastomas.

Nineteen hemangioblastomas, nine angioblastic meningiomas, ten metastases to the brain (including five renal cell carcinomas), and five primary renal cell carcinomas were studied using the immunoperoxidase method for Factor VIII related antigen and glial fibrillary acidic protein (GFAP). All tumor types showed Factor VIII immunoreactivity confined to endothelial cells. Factor VIII immunostaining revealed a distinct, though probably nondiagnostic, vascular pattern for hemangioblastomas as compared with metastatic carcinomas and angioblastic meningiomas. Most of the hemangioblastomas and metastases showed numerous GFAP-reactive cells with unequivocal astrocytic morphology primarily at the interface with brain parenchyma but also occasionally deep within the tumor. Within metastases these cells often were associated with penetrating fibrovascular septa. In a minority of hemangioblastomas and metastatic carcinomas there were rare GFAP immunoreactive cells that were indistinguishable from stromal or metastatic tumor cells, respectively. Angioblastic meningiomas showed no GFAP reactivity. It is concluded that the presence of GFAP-reactive cells alone is not helpful in differentiating between hemangioblastomas and intra-axial lesions. The lack of stromal cell immunoreactivity in angioblastic meningiomas and the rare staining of stromal cells in hemangioblastomas, seen also in central nervous system (CNS) metastases, suggest that except for the endothelial cells lining vessels, these primary CNS lesions are not antigenically closely related to either endothelial cells or astroglia. Furthermore, in the evaluation of tumors within the CNS, the significance of rare GFAP-positive tumor cells must be interpreted with caution.

Cerebellar Neoplasms↗
PubMed1984

Bone marrow transplant in adrenoleukodystrophy.

An allogeneic bone marrow transplant (BMT) from a normal HLA identical sibling donor was performed in a 13-year-old boy with rapidly progressive adrenoleukodystrophy (ALD). Engraftment and complete hematologic recovery occurred within 4 weeks, but neurologic deterioration continued. The patient died of an adenovirus infection 141 days after BMT. ALD is characterized by abnormally high plasma levels of very long chain fatty acids (VLCFA) as a result of impaired capacity to degrade them. Ten days after BMT, the white blood cell VLCFA levels and enzyme activity became normal; after 3 months, there was progressive reduction of plasma VLCFA to levels only slightly above normal.

Adolescent↗
PubMed1983

Basal forebrain neurons in the dementia of Parkinson disease.

Demented patients with Parkinson disease share certain neuropathological and neurochemical features with patients suffering from Alzheimer disease. Recently, loss of cholinergic neurons in the basal forebrain, particularly the nucleus basalis of Meynert, has been implicated in the pathophysiology of Alzheimer disease. The present investigations of 12 patients with Parkinson disease demonstrates that the demented patients with this disease also show a selective loss of cells in the nucleus basalis of Meynert, thus providing an important link between the dementias of Alzheimer disease and Parkinson disease.

Adult↗
PubMed1983

Early morphologic diagnosis of herpes simplex virus encephalitis: advantages of electron microscopy and immunoperoxidase staining.

The authors compared three morphologic techniques that can be used in the diagnosis of herpes simplex virus encephalitis. The pathologic material was derived from brain biopsy, autopsy, or both in ten culture-proven cases. On conventional light microscopic examination, typical intranuclear Cowdry type A inclusions were recorded as absent (one case), rare (six cases), or numerous (three cases). Electron microscopic evaluation, performed in nine cases, revealed intranuclear viral particles in five biopsy and two autopsy cases, including four cases in which inclusions were rare or absent on light microscopy. In one biopsy specimen, unequivocal virus particles could not be identified ultrastructurally, although they were present in subsequent autopsy material. Immunoperoxidase staining using the peroxidase-antiperoxidase (PAP) method and type-specific anti-herpes simplex type 1 antiserum, performed on paraffin-embedded tissue, demonstrated strongly positive specific immunoreactivity in all ten cases. The potential for rapid specimen preparation, the relative sensitivity of electron microscopy, and the extreme sensitivity and specificity of the PAP-immunoperoxidase method offer obvious advantages in the early morphologic diagnosis of herpes simplex virus encephalitis.

Brain↗
PubMed1983

Crohn's disease and ulcerative colitis in the same patient.

A well documented case of a patient with both Crohn's disease and ulcerative colitis is presented. A 29 year old woman underwent resection of her terminal ileum and ascending colon for typical Crohn's disease with ileocolitis. Eleven years later, an ileoproctocolectomy was performed for typical ulcerative colitis involving the left colon. The resection specimen also showed evidence of colonic Crohn's disease near the anastomotic site. This unusual case shows that Crohn's disease and ulcerative colitis can occur in the same patient. The rarity of such cases supports the concept that Crohn's disease and ulcerative colitis are separate entities, rather than different manifestations of the same disease process.

Adult↗
PubMed1983

Cortical and subcortical components of the pattern VEP.

Studies in the past have shown that wavelength related VEPs can be recorded from both cortical and noncortical sites. Elements of pattern-specific VEPs for both transient and pattern-reversal stimuli are also obtained from these sites. From the noncortical montage consistent responses are obtained with a major component at about 100 msec, which has been found for both the wavelength related and pattern related VEP. In contrast, the cortical VEP to both types of stimuli include two major components, at around 100 and 200 msec. In pattern reversal these components react quite differently to changes in spatial frequency. The component around 100 msec reacts strongly to a wide range of spatial frequencies when recorded from either cortical or noncortical sites. In contrast, the component around 200 msec, obtained with cortical recording, reacts very strongly to high spatial frequencies and very weakly to low spatial frequencies. This finding corresponds to recent results of single-cell studies in the macaque LGN and striate cortex.

Adult↗
PubMed1983

Pattern component ratio in pattern-reversal VEP: normative data and clinical applications.

It has been well established that there is a reliable implicit time to the VEP positive component (ca 100 msec) in response to pattern reversal. This has become a valuable test of the status of the visual system. Recent data suggest that activity around 200 msec is another useful measure of the cortical response to pattern alternation. We have carried out a normative study of the relative amplitudes of the two components. Among adults with normal visual acuity activity around 200 msec is directly related to the spatial frequency of the stimulus, peaking markedly in amplitude at a narrow range of spatial frequencies. This is in sharp contrast to the earlier component, which does not exhibit such sensitive size differentiation. Recently we have used the ratio between the late and early component amplitudes as a quantitative indicator of the efficiency of higher-level processing of pattern information. We present our normative data and illustrate the effects of decreased visual responses not related to known peripheral optical problems. The results of this work are also interpreted as showing basic characteristics of information processing in the visual system, in that higher spatial frequencies are processed by a continuum of rather sharply tuned cortical processes, with the higher spatial frequencies being processed later in time.

Evoked Potentials, Visual↗
PubMed1982

Preschool assessment of infants with a patent ductus arteriosus: comparison of ligation and indomethacin therapy.

We report the preschool growth and development of preterm infants with problematic patent ductus artferiosus requiring either surgical ligation or indomethacinn treatment in the neonatal period. Of 60 who completed longitudinal growth assessments, no differences in growth to 3 years could be demonstrated except for four cases of regressed retinopathy of prematurity among the ligated infants. Developmental tests (Bayley Scales of Infant Development and the Peabody Picture Vocabulary Test) showed no group differences at preschool ages. Although psychomotor performance on the Bayley Scales in the first 1 1/2 years was significantly lower among the surgically treated infants, later analysis showed that a similar number in both treatment groups scored within the normal range. No selective short- or long-term adverse effects of indomethacin treatment could be demonstrated.

Body Height↗
PubMed1982

Improved rabbit brain tumor model amenable to diagnostic radiographic procedures.

The VX2 carcinoma was used to create a rabbit brain tumor model. VX2 tumors were chemically dissociated and suspended in liquid medium. Twenty-five microliters of the tumor suspension containing 3 X 10(3), 3 X 10(4), or 3 X 10(5) viable tumor cells were injected through cranial burr holes 6 mm into the right frontoparietal lobes of 17 rabbits. Fifteen of these developed histologically documented nodular intraparenchymal tumors. Tumors were demonstrable with cerebral computed tomographic scans and by cerebral angiography. The feasibility of surgical resection of lesions using the fluorescein staining technique was also demonstrated. This animal brain tumor model is suitable for neuro-oncology research focusing on imaging and therapeutic techniques.

Animals↗
PubMed1980

Sulfur--selenium studies in sheep. II. Effect of a dietary sulfur deficiency on selenium and sulfur metabolism in sheep fed varying levels of selenomethionine.

The effect of a sulfur deficiency on the metabolism of selenium and sulfur was investigated in eight merino wethers. The sheep were fed high-sulfur (2 g S/kg) or low-sulfur (0.5 g S/kg) diets for two periods of 35 days each, and received selenium as selenomethionine at dietary concentrations of 0.02, 0.06, 0.09 and 0.67 mg Se/kg. Sheep fed the low-sulfur diet had reduced feed intake, reduced nitrogen, sulfur and selenium balance, but elevated plasma and wool selenium concentrations. Selenium concentrations in organs and tissues of slaughtered animals paralleled the selenium intake of the animal, with the renal cortex containing the highest concentration and bone the lowest. The effect of the 0.5 g S/kg diet on feed intake is in contrast with the results from the previous experiment (White and Somers 1977) using 0.7 g S/kg. It is this difference in fed intake which was responsible for many of the effects on selenium metabolism observed in this experiment. Once the feed intake effects are accounted for, the implications for sulfur--selenium interactions remain as before, i.e. more selenium is incorporated into wool and plasma protein when dietary sulfur is limiting than when it is not.

Animals↗
PubMed1979

Patent ductus arteriosus treated with ligation or indomethacin: a follow-up study.

The course and complications of fifty-two infants with patent ductus arteriosus requiring closure were assessed prospectively. Twenty-six infants with a PDA received indomethacin for pharmacologic closure of the PDA, and 26 underwent ligation. The current study analyzes and compares the longitudinal follow-up with respect to somatic growth, neurologic function, psychomotor and mental development, and renal, ophthalmologic, and audiologic function in 21 infants in each group who entered the follow-up. No selective morbidity was attributable to PDA closure with indomethacin when compared to surgically treated infants.

Child Development↗
PubMed1979

The effect of sulphur on 75Se absorption and retention in sheep.

Four Border-Leicester X Merino wethers were used in a 4 X 4 Latin square experiment to study the effects of dietary sulphur on selenium absorption and retention. The basal diet contained 0.05% S and sodium sulphate was added to give additional treatment levels of 0.11, 0.17 and 0.24% total sulphur. Sodium selenate was added to all diets to bring the dietary selenium level to a constant 0.25 mg/kg. One hundred muCi 75Se as sodium selenate (specific activity 50 muCi/mg Se) was administered to the rumen per fistulam after a 10-day period of adjustment on each diet. Radioactivity in blood, urine, faeces and rumen digesta was measured at intervals over the succeeding 7 days. Twenty percent of the total activity in the rumen fluid was in the TCA supernatant fraction after 3 hours, and this proportion tended to increase slightly as sulphur intake increased. Fecal excretion of selenium accounted for between 44 and 51% of the dose after 7 days, the high levels being associated with increasing sulphur intake. However, these differences were not significant. Urinary excretion of selenium accounted for between 12% (0.05% S) and 22% (0.24% S) of the dose after 7 days, with treatment differences being significant. Levels of radioactivity in blood were significantly higher in sheep fed the 0.05% S diet compared with those fed the higher levels. The results show that sulphur affects apparent selenium excretion and suggest that the metabolism of these two elements is intimately related.

Absorption↗
PubMed1979

The electrocardiogram in ambulatory medical practice.

The electrocardiogram is one of medicine's most frequently ordered procedures. A review of the current use of electrocardiograms in ambulatory clinical practice and the possible information that might be supplied by an electrocardiogram was undertaken. The electrocardiogram's advantages and disadvantages when used in evaluating specific cardiac disorders are discussed including the use of the electrocardiogram as a baseline. Both their values and their limitations in diagnosis and management are examined to support the authors' conclusion that electrocardiograms should be used as an adjunct to clinical diagnosis, not as a screening procedure.

Ambulatory Care↗