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Biomedical subjects

C Harper

Publications and source records attributed to C Harper.

At least 91 records · Page 5Linked to original sources
PubMed1986

The effects of serum, lithium, ethacrynic acid, and a low external concentration of potassium on specific [3H]-ouabain binding to human lymphocytes after incubation for 3 days.

We have quantified specific [3H]-ouabain binding sites in normal human lymphocytes, and have measured the changes in the numbers of those sites which occur in response to various stimuli. We have confirmed previous findings that incubation for 72 h in the presence of fetal calf serum causes an increase in [3H]-ouabain binding, and that this does not occur if the cells are incubated in fetal calf serum which has first been dialysed. During incubation of the lymphocytes for 3 days in the presence of dialysed fetal calf serum each of the following stimuli caused an increase in specific [3H]-ouabain binding: addition of ethacrynic acid (1 mumol l-1), addition of lithium (1 mmol l-1), and reduction of the external potassium concentration (to 0.75 mmol l-1). By analogy with the similar results in HeLa cells reported by others, we suggest that the increase in [3H]-ouabain binding may, in the case of ethacrynic acid and the reduction of the external potassium concentration, be initiated by an increase in the intracellular sodium concentration. The mechanisms whereby fetal calf serum and lithium cause an increase in [3H]-ouabain binding are not clear.

Acridines↗
PubMed1986

Acute encephalopathy and death due to petrol sniffing: neuropathological findings.

A 25 year old man with a five year history of petrol sniffing developed an acute encephalopathy with abnormal body movements and died of aspiration pneumonia. Neuropathological findings included chromatolysis of neurons in the reticular formation and cerebral cortex and loss of neurons in the h3-5 sector of Ammon's horn and the cerebellum. Toxicological studies suggest that the encephalopathy is caused by the tetraethyl-lead additive in the petrol. These data support previous human and experimental studies.

Acute Disease↗
PubMed1985

Leigh's disease: a cause of arterial hypertension.

An 11-year-old boy developed sudden and severe arterial hypertension. A post-mortem examination revealed bilateral symmetrical lesions in the medulla oblongata which were typical of Leigh's disease (subacute necrotizing encephalomyelopathy). Other cases of Leigh's disease with hypertension or left ventricular hypertrophy have shown similar brain stem lesions. Bilateral lesions of Leigh's disease in the dorsal medulla involving the solitary tract and nucleus can cause neurogenic hypertension and this may be an important clinical sign which has been neglected.

Brain Diseases, Metabolic↗
PubMed1985

Cation transport functions in vitro in patients with untreated essential hypertension: a comparison of erythrocytes and leucocytes.

We have measured intracellular sodium concentrations and specific 3H-labelled glycoside binding characteristics in the erythrocytes and leucocytes of patients with untreated essential hypertension, and have compared the results with those in well-matched normotensive control subjects. Intracellular sodium concentrations were increased in the leucocytes, but not in the erythrocytes, of patients with untreated essential hypertension. There were no differences in the 3H-labelled glycoside binding characteristics of either the erythrocytes or the leucocytes of hypertensive and normotensive subjects. There was no difference in the ability of plasma samples from hypertensive and normotensive subjects to inhibit the binding of [3H]-ouabain to intact leucocytes from normotensive subjects. These findings are not consistent with the presence of increased concentrations of a substance which behaves like a cardiac glycoside in the circulation of patients with untreated essential hypertension.

Adult↗
PubMed1985

Needle muscle biopsy: will it make open biopsy obsolete?

Seventy-five needle muscle biopsies have been performed in this department over the past two years. Adequate biopsies were obtained in 69 cases. In 40 cases a variety of neuromuscular conditions was seen, broadly categorised as necrotizing myopathy (10), neurogenic atrophy (7), metabolic myopathy (5), vasculitis (2), normal muscle (7), and non-specific changes (9). Twenty-nine cases were for muscular dystrophy carrier detection. There were no complications associated with the procedure. The technique is simple and quick, and can be performed on outpatients or in the ward. Needle biopsy is the method of choice for sampling skeletal muscle in most patients, although open biopsy is still indicated for certain conditions.

Adolescent↗
PubMed1985

Brain atrophy in chronic alcoholic patients: a quantitative pathological study.

There are essentially no objective neuropathological data on brain atrophy in chronic alcoholic patients despite numerous neuroradiological studies which show a high incidence of shrinkage or atrophy. Therefore measurements were made of the intracranial volume (ICV) and brain volume (BV) in a necropsy study of 25 chronic alcoholic patients and 44 controls. The pericerebral space (PICS) was calculated according to the formula (formula; see text) The PICS will increase in patients with brain atrophy since the ICV remains constant throughout life. The mean PICS value was 8.3% in controls, 11.3% in the alcoholic group, 14.7% in alcoholics with superimposed Wernicke's encephalopathy (thiamine deficiency) and 16.2% in those alcoholics with associated liver disease. Thus there was a statistically significant loss of brain tissue in chronic alcoholic patients which appeared to be more severe in those with associated nutritional vitamin deficiencies or alcoholic liver disease.

Adult↗
PubMed1984

Erythrocytic cation transport receptor numbers and activity in pregnancies complicated by essential hypertension and pre-eclampsia.

Various functions of erythrocytic cation transport were studied in normotensive and hypertensive pregnancy (women with pre-eclampsia and essential hypertension). The results showed that in pregnancy there is an increase in the number of erythrocytic glycoside binding sites accompanied by a proportional increase in the active inward transport of rubidium (used as a substitute for potassium). There was no evidence of an effect of pregnancy on intraerythrocytic sodium concentrations. These changes were apparently entirely attributable to pregnancy and not affected by pre-eclampsia or essential hypertension. It is suggested that these alterations indicate an adaptive increase in sodium pump numbers and activity secondary to a tendency for the intraerythrocytic sodium concentration to rise during pregnancy and compensating for that tendency.

Adolescent↗
PubMed1984

Atypical meningiomas: clinical pathological correlation.

Four cases of atypical meningiomas with aggressive histological features have been reviewed. Atypical histological features may indicate higher probability and more rapidity of recurrence. The pertinent literature has been reviewed.

Aged↗
PubMed1984

Embolization of small vessels with a double-lumen microballoon catheter. Part II: Laboratory, animal, and histological studies. Work in progress.

A double-lumen microballoon catheter system measuring 0.5-0.85 mm in outer diameter (1.3-2.8 F) was fabricated for passage through standard 4.1 and 5 F catheters. By arresting circulation with the balloon, embolization with low-viscosity silicone rubber, ethanol, or isobutyl-2-cyanoacrylate can proceed in a methodical, unhurried manner, permitting precise control of tissue penetration and preventing paradoxical embolization of other vessels. Problems such as gluing the catheter in situ with cyanoacrylate did not occur. The catheter may also be inserted during surgery to control embolization at a remote site, which did result in the catheter being glued in situ in one case.

Animals↗
PubMed1983

Angiographically occult cerebral vascular malformations with abnormal computed tomography.

Two cases of histologically proven cerebrovascular malformation were detected by computed tomography (CT) scanning but not by cerebral angiography. One of the patients had a cavernous angioma and the other an arteriovenous malformation. Caution is advised in assuming that angiographically avascular lesions demonstrable by CT scanning are not vascular malformations.

Adult↗
PubMed1983

Proliferative vasculopathy and an hydranencephalic-hydrocephalic syndrome: a neuropathological study of two siblings.

Two female siblings were born with an hydranencephalic-hydrocephalic syndrome, following pregnancies complicated by hydramnios. No environmental factors such as infections, drugs or metabolic disorders were noted during either pregnancy. Neuropathological studies revealed identical changes in each case. The characteristic feature of the pathology was a proliferative vasculopathy throughout the central nervous system, which apparently caused focal ischaemic lesions and progressive destruction of CNS tissue. The defect probably is inherited as an autosomal recessive trait.

Anencephaly↗
PubMed1983

The incidence of Wernicke's encephalopathy in Australia--a neuropathological study of 131 cases.

In a nine year necropsy study in Western Australia, the incidence of Wernicke's encephalopathy was 2.8%. The incidence appears to be increasing. Although Wernicke's encephalopathy is a nutritional disorder, the majority of cases occur in the alcoholic population. Only 20% of the 131 cases studied had been diagnosed clinically as Wernicke's encephalopathy. This large discrepancy between numbers of cases diagnosed clinically and pathologically suggests that chronic Wernicke's encephalopathy, which comprised 83% of the cases, may be the end result of repeated subclinical episodes of Wernicke's encephalopathy. Thus, Wernicke's encephalopathy could be considered a "progressive" disorder and as patients respond well to thiamine replacement therapy, early diagnosis is important. Alternatively, prevention by vitamin enrichment of alcoholic beverages may have to be considered in an attempt to minimise the social and economic impact of Wernicke's encephalopathy on Western society.

Adult↗
PubMed1983

Depressive illness as a presentation of primary lymphoma of the central nervous system.

A 65-year-old man was referred from a medical unit for psychiatric assessment of a depressive illness associated with intermittent vomiting. No organic disorder was identifiable after the initial clinical examination and extensive investigations. A primary lymphoma involving the limbic system was eventually detected on repeat CAT scan and was confirmed at autopsy. This tumour, which is increasing in incidence, is notoriously difficult to diagnose and frequently presents with combined psychological and organic symptoms. It may be radiosensitive if detected early enough.

Aged↗