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Biomedical subjects

M J Ball

Publications and source records attributed to M J Ball.

At least 109 records · Page 6Linked to original sources
PubMed1991

New biochemical insights to unravel the pathogenesis of Alzheimer's lesions.

Purification of amyloid plaque core proteins (APCP) from Alzheimer's disease brains to complete homogeneity and in high yield permitted its chemical fractionation and characterization of its components. APCP is mainly made of beta-amyloid (beta A) and an assortment of glycoproteins (accounting for 20%) rich in carbohydrates compatible with N- and O-linked saccharides. When added to tissue culture of sympathetic and sensory neurons APCP and beta A inhibited neuritic sprouting, a reversible phenomenon at low doses. Higher concentrations of both substances kill the neurons in culture. APCP is significantly more toxic than beta A, suggesting the minor components may play an important role in increasing the toxicity of beta A. If the observed toxic effects of APCP in situ are occurring in vivo during the course of AD, then the accumulation of these extracellular proteins could be largely responsible for some of the neuronal death observed in this neuropathology.

Alzheimer Disease↗
PubMed1991

Hematological and biochemical effects of parenteral nutrition with medium-chain triglycerides: comparison with long-chain triglycerides.

Twenty-four malnourished patients requiring total parenteral nutrition were randomly assigned to receive a daily infusion of either Lipofundin MCT-LCT [a new lipid preparation containing medium-chain triglycerides (MCTs)], or Lipofundin S [a long-chain triglyceride (LCT) preparation] for 6-28 d. No adverse clinical effects were apparent in patients receiving the new emulsion. Hematological indices were unchanged. Plasma urea concentrations rose less on MCT-LCT than on LCT and the plasma bilirubin concentration was lower. Plasma ketones were higher immediately after the MCT-LCT infusion but not at other times. Triglyceride and fatty acid concentrations were similar. Insulin concentrations were higher on MCT-LCT than on LCT. Daily nitrogen balance values were not significantly different between the two groups. Urinary carnitine excretion fell dramatically on both lipids.

Bilirubin↗
PubMed1991

Effects of increasing quantities of oat bran in hypercholesterolemic people.

The effects of increasing quantities of oat bran on plasma lipids were examined in 40 hypercholesterolemic men and women. Using a four-by-four Latin-square design, subjects added 30, 60, and 90 g oat bran/d or no oat bran to their usual diet for 1-mo experimental periods. Self-selected background diets remained unchanged and weight did not change significantly. No differences in plasma total or low-density-lipoprotein cholesterol were found. Supplementation of the usual diet with less than or equal to 90 g oat bran does not appear to significantly lower cholesterol in hypercholesterolemic subjects continuing to follow a diet relatively high in saturated fatty acids.

Adult↗
PubMed1991

Asymptomatic hypothyroidism and hypercholesterolaemia.

Hypothyroidism is a cause of secondary hyperlipidaemia. This study investigates the frequency of biochemically diagnosed hypothyroidism and its relationship with plasma cholesterol concentration in apparently healthy people. Thyroid function tests (total T4, TSH, and free T4) were performed on 272 apparently healthy men and women (179 vegetarians, 93 meat eaters) with a plasma cholesterol concentration above 7 mmol/l and on 90 individuals with a plasma cholesterol below 4.1 mmol/l who were matched for age, sex and dietary habits. Six per cent of those with a plasma cholesterol above 7 mmol/l had biochemical evidence of hypothyroidism as defined by a TSH greater than 10 mIU/l (reference range 1-6) and a low free T4 below 10 pmol/l (reference range 10.1-25). Eighty per cent of these people had a high titre of thyroid anti-microsomal antibodies. Of the 90 individuals with a plasma cholesterol level below 4.1 and the 25 randomly selected participants none had biochemical evidence of hypothyroidism. Hypothyroidism is relatively common in apparently healthy people with a raised plasma cholesterol. It appears no commoner in vegetarians than in meat eaters.

Adult↗
PubMed1991

Very mild Alzheimer's disease: informant-based clinical, psychometric, and pathologic distinction from normal aging.

We compare clinicopathologic data from 10 subjects identified in the very mild stage of senile dementia of the Alzheimer type with findings from similar studies in four cognitively normal subjects. We based the diagnosis of very mild dementia in the 10 subjects on informant reports and the judgment of experienced clinicians. Deficits of some psychometric measures of memory, language, and speeded psychomotor performance were observed for these subjects. The histologic markers of Alzheimer's disease, including neurofibrillary tangles and both the "diffuse" and classic subtypes of senile plaques, were present in the neocortex in all 10 subjects but essentially were absent in the four controls. These findings indicate that even "questionable" dementia can be diagnostic for Alzheimer's disease. Furthermore, because truly normal aging may be unaccompanied by neocortical senile plaques and neurofibrillary tangles, the presence of these lesions should suggest the possibility of clinically undetected Alzheimer's disease.

Activities of Daily Living↗
PubMed1991

APP717, APP693, and PRIP gene mutations are rare in Alzheimer disease.

The amyloid precursor protein (APP) gene codes for the precursor to the beta-protein found in the amyloid deposits of Alzheimer disease (AD). Recently Goate et al. identified in codon 717 of this gene a missense mutation which segregates with AD in a familial AD (FAD) kindred. The same mutation was also found in affected subjects from a second FAD family but not in other FAD families or in normal controls. The following work was undertaken to determine the frequency of the codon 717 mutation in FAD and nonfamilial AD cases and in normal controls. We tested 76 FAD families, 127 "sporadic" AD subjects, 16 Down syndrome cases, and 256 normal controls for this mutation, and none were positive. We also tested for the APP codon 693 mutation associated with hereditary cerebral hemorrhage with amyloidosis-Dutch type, for PRIP gene missense mutations at codons 102, 117, and 200, and for the PRIP insertion mutations which are associated with Creutzfeld-Jakob disease and Gerstmann-Straussler Scheinker syndrome. No examples of these mutations were found in our population. Thus these APP and PRIP mutations are rare in both FAD and nonfamilial AD.

Adult↗
PubMed1991

Hospital information systems (HIS): looking into the future.

Hospital information systems have to date failed to live up to the expectations of healthcare providers and informaticians. Events in the summer of 1991 call for major changes in healthcare, and new technologies offer the power to make the computer-based patient record a reality.

Computer Systems↗
PubMed1990

Comparison of two triphasic contraceptives with different progestogens: effects on metabolism and coagulation proteins.

This study compared the effects of two triphasic oral contraceptives (OCs) taken for 6 pill cycles. One preparation contained levonorgestrel (EE/LN), the other a new progestagen, gestodene (SHG 415G). There were no effects on body weight, dietary habits, blood pressure, HDL-cholesterol or carbohydrate metabolism. Both OCs caused a small but statistically significant increase in plasma total cholesterol, LDL-cholesterol, LDL/HDL-cholesterol ratio and triglyceride concentration. Sex hormone binding globulin was increased by both preparations. Coagulation factor VII and fibrinogen were increased and antithrombin III levels reduced, indicating that both preparations had pro-coagulant activity. The gestodene triphasic preparation was associated with minor side effects similar to those experienced on EE/LN. The metabolic effects were similar despite the lower total steroid dose of the gestodene preparation.

Adolescent↗
PubMed1990

The effect of parenteral nutrition with different lipid emulsions on platelets.

This study investigated the effect of parenteral nutrition including 500 ml/day of two different lipid emulsions on platelet numbers and platelet aggregation. One lipid contained 20% long chain triglycerides, the other a mixture of 10% medium chain triglycerides and 10% long chain triglycerides. After 7-10 days parenteral feeding, platelet numbers had not changed significantly, platelet morphology appeared normal and the prothrombin time was unaltered. Platelet aggregation in response to varying concentrations of ADP, adrenaline and collagen was not significantly different from pre-feeding and was similar in patients receiving the two different lipids.

Journal Article↗
PubMed1990

Buprenorphine disposition in patients with renal impairment: single and continuous dosing, with special reference to metabolites.

The disposition of buprenorphine has been studied in two patient groups to assess the influence of impaired renal function on the metabolism of buprenorphine and two of its metabolites, buprenorphine-3-glucuronide (B3G) and norbuprenorphine (NorB). A single i.v. dose of 0.3 mg was given to 15 patients (nine with dialysis-dependent renal failure) undergoing lower abdominal or peripheral body surface surgery. Blood was sampled up to 24 h. Concentrations of buprenorphine, B3G and NorB were assayed by a differential radioimmunoassay technique. There were no differences in buprenorphine kinetics between anaesthetized healthy patients and those with renal impairment: mean elimination half-lives 398 and 239 min; clearance 651 and 988 ml min-1; apparent volume of distribution at steady state 313 and 201 litre, respectively. Both metabolites were undetectable following the single i.v. dose. In a second group of 20 patients (eight with renal impairment), buprenorphine was administered by continuous infusion for provision of analgesia and control of ventilation in the ITU (median infusion rate 161 micrograms h-1 (range 36-230 micrograms h-1) for a median duration of 30 h (2-565 h). Buprenorphine clearance in patients with normal and impaired renal function was similar (934 and 1102 ml min-1, respectively), as were dose-corrected plasma concentrations of buprenorphine. In patients with renal failure, plasma concentrations of NorB were increased by a median of four times, and B3G concentrations by a median of 15 times.

Adolescent↗
PubMed1990

Human herpes virus infections and Alzheimer's disease.

Herpes viruses cause acute and chronic diseases of the peripheral and central nervous systems and have been implicated in the aetiology of Alzheimer's disease (AD). In this investigation the relevance of human herpes virus infection to AD was assessed by in situ hybridization. The abundant latency associated transcript(s) of herpes simplex virus type 1 (HSV-1) were detected at a significantly higher incidence in the trigeminal ganglia of individuals with AD than in controls. But we could find no evidence of viral RNA in the central nervous system (CNS), looking specifically in the hippocampal cortex of demented individuals with extensive neuropathological changes of AD. These studies solve one problem in testing the viral hypothesis of causation, i.e. the sensitivity of the methods used in the search for latent infection. But the central issue remains unresolved because of necessity, only the end stage of a prolonged pathophysiological process has been examined. Our conclusions are qualified accordingly.

Alzheimer Disease↗
PubMed1990

Subgroups in dementia of the Alzheimer type identified using positron emission tomography.

We examined patterns of cerebral glucose metabolism in 33 patients with dementia of the Alzheimer type by applying principal component analysis to identify subgroups. Four subgroups were identified: one with predominant parietotemporal hypometabolism (15 patients); one with paralimbic metabolic deficits (8 patients); one with left hemisphere neocortical abnormality (5 patients); and one with frontal and parietotemporal deficit (5 patients). Differences among the subgroups were found in neuropsychological impairments and prevalence of psychiatric symptoms. These metabolic subgroups could not be explained on the basis of dementia severity, illness duration, or age, but were most likely related to an underlying pathology with a variable regional distribution.

Aged↗
PubMed1990

Computers in health care for the 21st century.

As the world enters the last decade of the 20th Century, there is a great deal of speculation about the effect of computers on the future delivery of health care. In this article, the authors attempt to identify some of the evolving computer technologies and anticipate what effect they will have by the year 2000. Rather than listing potential accomplishments, each of the affected areas: hardware, software, health care systems and communications, are presented in an evolutionary manner so the reader can better appreciate where we have been and where we are going.

Artificial Intelligence↗