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Biomedical subjects

A Young

Publications and source records attributed to A Young.

At least 271 records · Page 15Linked to original sources
PubMed1988

Assessment for rehabilitation after stroke.

There is some evidence that the rehabilitation of patients who have suffered a stroke may be more successful if conducted in a specialist unit, especially if started soon after the stroke. Departments of Geriatric Medicine are often unable to accept all invitations to take over the rehabilitation of elderly patients who have suffered a stroke. As specialist rehabilitation resources are scarce, it is necessary to be able to distinguish the patients whose outcome will be improved by specialist rehabilitation from those whose recovery (whether good or bad) will not be significantly influenced. Patients with an Edinburgh prognostic score of 5.6 four weeks after the stroke are very likely always to require total nursing care even after specialist rehabilitation. A Guy's Hospital prognostic score of 10 or more seems to indicate that functional independence will be recovered even without specialist rehabilitation. Patients with an Edinburgh prognostic score of 3-4 within the first 4 weeks after the stroke should not be denied specialist rehabilitation; there is evidence, admittedly weak, that it is for them that the benefits may be greatest. A major study is now required to validate the Edinburgh and Guy's prognostic scores prospectively and to test whether it is valid to use them for the triage of elderly patients for specialist rehabilitation. In addition, it is possible that a specialist unit would be better able to help patients with specific 'barriers' to rehabilitation. Adequate tools for the identification and objective assessment of these barriers are essential if this possibility is to be tested.

Cerebrovascular Disorders↗
PubMed1987

A prospective study of early onset rheumatoid arthritis over fifteen years: prognostic features and outcome.

A total of 218 patients with early onset rheumatoid arthritis were entered into a prospective study over fifteen years. Of these, 151 remained in the study at three years (of whom 14 died), and a further 39 (23 deaths) defaulted after this time. The severity of disease was assessed by four different methods. Although persistently active joint disease was recorded in 26% of patients, only 13% had severe functional impairment, and only 14% developed severe erosions. An episode of RA lasting two to three years followed by complete remission with none or minimal sequelae ("non recurrent" RA) was present in 34%. Using discriminant analysis, which selected rheumatoid factor, haemoglobin level and platelet count from a number of clinical and laboratory variables measured at onset, it was possible to predict three mutually exclusive outcome categories correctly in 50-60% of patients depending on the method of assessment of outcome.

Adolescent↗
PubMed1987

Propranolol blocks metabolic rate increase but not ventilatory acclimatization to 4300 m.

Previously, we found resting metabolic rate increased at high altitude but the mechanism and consequences of this increase were unclear. We sought to test the role of beta-sympathetic activation for increasing metabolic rate and the contribution of an increase in metabolic rate to raising total ventilation at altitude. Following baseline studies at sea level, two groups of six healthy male subjects received either placebo or propranolol (80 mg/8 h) for 3 days prior to ascent to Pikes Peak (4300 m) where treatment was continued for 15 days. O2 consumption increased in placebo-treated subjects with a rise of 20 +/- 5% (X +/- SEM) on day 1 and no change 0 +/- 7% in propranolol-treated subjects (difference between groups, P less than 0.05). The increase in total ventilation upon ascent was 28 +/- 2% in the placebo group vs 9 +/- 7% in the propranolol group (P less than 0.05) and was correlated with metabolic rate in individual subjects. Decreasing end-tidal PCO2, taken as an index of ventilatory acclimatization, was similar in both groups. Thus, beta-sympathetic activation appears to increase metabolic rate upon ascent to high altitude and lead to a proportionate elevation in total ventilation but does not alter ventilatory acclimatization.

Acclimatization↗
PubMed1987

Rapid detection of cytomegalovirus by tissue culture, centrifugation, and immunofluorescence with a monoclonal antibody to an early nuclear antigen.

A rapid, sensitive and specific assay for the detection of cytomegalovirus (CMV) was developed utilizing MRC-5 cells in 24-well plates containing round coverslips. Centrifugation expedited the detection of CMV early antigen with monoclonal antibody. Immunofluorescent staining 16 h after inoculation with a stock CMV preparation (AD-169), demonstrated an 11-fold increase in the number of nuclear inclusions when the specimens were centrifuged (18 +/- 2.2) as compared to the non-centrifuged specimen (1.6 +/- 0.9). However, the number of nuclear inclusions depended on the age of the MRC-5 cells. They were more sensitive to CMV infection between 4 and 11 days after the cells were seeded into plates. Among 159 patient samples cultured for CMV, 23 (14%) were positive by the rapid method (mean of 32 h) and 18 (11%) by routine tissue culture (mean of 12 days). Cytomegalovirus in urine was detected within 1.3 days, whereas buffy coats (2.3 days) and bronchial washings (2.5 days) took longer. Staining for CMV inclusions at more than one time point was necessary for the optimal detection of CMV by the rapid method. We recommend using this assay system as it is rapid, specific, sensitive and versatile for the detection of CMV in many biological specimens.

Antibodies, Monoclonal↗
PubMed1987

Detection of cytomegalovirus by 24-well plate centrifugation assay using a monoclonal antibody to an early nuclear antigen and by conventional cell culture.

During a 12-month period, two methods for detection of cytomegalovirus (CMV) in 1624 clinical specimens were compared: (1) centrifugal inoculation of MRC-5 cells on coverslips in 24-well plates and staining with a monoclonal antibody to CMV early nuclear antigen after incubation for 40 h (EA assay), and (2) conventional tube cell culture. CMV was identified in 183 (11.3%) specimens from 113 different patients. The EA assay was positive for CMV in 144/183 specimens (79%), and CMV was detected by recognition of specific cytopathic effect (CPE) in conventional cell culture in 143/183 (78%). Both methods yielded CMV in 56% of the specimens (104/183). CMV was detected by EA assay alone in 22% (40/183) and only by CPE in 21% (39/183) of the positive specimens. When all specimen types were considered, there was no significant difference in the detection of CMV between the two methods. However, bronchoalveolar lavage (BAL) fluids yielded CMV more frequently by EA assay than by CPE (58 compared to 48 of 574, p = 0.0178), and CMV was detected in blood specimens more often by CPE than by EA assay (20 compared to one of 149, p less than 0.0001). In addition to CMV, other viruses were recovered by conventional tube cell culture, including herpes simplex virus (HSV) type 1 from 17 BAL fluids (two of which were positive for CMV by EA assay) and one liver biopsy and adenovirus serotype 4 from four separate urine specimens and three gastrointestinal tract biopsies from one patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1987

Faces interfere with name classification in a prosopagnosic patient.

Since sustaining a severe closed head injury P.H. has been completely unable to recognise familiar faces, but remains able to identify written names. Despite his inability to recognise faces overtly, P.H. nevertheless shows a normal pattern of interference from simultaneously presented distractor faces in a politician vs nonpolitician name classification task. His reaction times for semantic (politician versus nonpolitician) classification of printed names are slowed by the presence of a face drawn from the incorrect semantic category. This interference is found even though P.H. performs at chance level when asked to overtly classify the faces used in the task. The finding demonstrates that prosopagnosic patients may covertly achieve relatively precise recognition of familiar faces and access to semantic information.

Adult↗
PubMed1987

Rectal necrosis after a phosphate enema.

We describe a patient who developed rectal ulceration after an apparently minor injury caused during the administration of a 130 ml 'disposable' phosphates enema. Treatment included parenteral antibiotics and a colostomy. Minor degrees of injury by rectal procedures are common. Rectal necrosis is a complication of injury during the administration of phosphates enemata which, although rare, deserves greater awareness. Painless rectal bleeding may be the only sign of injury and is an indication for thorough and repeated rectal examinations and early intervention.

Aged↗
PubMed1987

Comparison of serum cardiac specific troponin-I with creatine kinase, creatine kinase-MB isoenzyme, tropomyosin, myoglobin and C-reactive protein release in marathon runners: cardiac or skeletal muscle trauma?

Problems arise in distinguishing skeletal from cardiac muscle trauma on the basis of serum enzyme tests following severe muscle exercise. The contributions of cardiac and skeletal sources have been assessed in eleven marathon runners by measuring pre- and post-race serum levels of cardiac-specific myofibrillar troponin-I together with total creatine kinase, creatine kinase-MB isoenzyme, myoglobin, myofibrillar tropomyosin and C-reactive protein. Total creatine kinase, creatine kinase-MB isoenzyme, tropomyosin and myoglobin were significantly elevated above pre-race levels in all runners between 1 h and 128 h post-race. Neither mean cardiac troponin-I nor C-reactive protein was elevated post-race. Nine out of sixty-three samples fulfilled conventional positive criteria for cardiac muscle damage on the basis of combined creatine kinase and creatine kinase-MB isoenzyme levels. Six runners had one or more positive samples. No samples had levels above twice the upper normal limit for either cardiac troponin-I or C-reactive protein. Correlation analysis of levels in each sample indicated skeletal and not cardiac muscle as the source of raised serum protein.

Athletic Injuries↗
PubMed1987

Induction of ventricular arrhythmias by programmed ventricular stimulation: a prospective study on the effects of stimulation current on arrhythmia induction.

A protocol for programmed ventricular stimulation is described in which the effect of increasing stimulation current on ventricular refractoriness and arrhythmia induction was specifically examined. The protocol was evaluated prospectively in 70 patients undergoing electrophysiological study for documented or suspected ventricular arrhythmias. Programmed electrical stimulation was performed at the right ventricular apex and outflow tract using single and double extrastimuli and burst pacing. Stimulation currents of 2, 5, 10, and 20 mA were used in ascending order. The initial (lowest) current was never less than twice diastolic threshold and was maintained during each stimulation run until refractoriness was reached. The current was then increased to the next level to facilitate premature capture until refractoriness was encountered at 20 mA or a sustained arrhythmia occurred. Ventricular arrhythmias were induced in 34 patients, 31 of whom had presented with a sustained ventricular arrhythmia. The incidence of induced arrhythmias was low in those patients who had presented with symptoms alone, a non-sustained arrhythmia, or a sustained arrhythmia in association with a predisposing clinical event. Only one patient with a negative result had further ventricular arrhythmias during the mean follow up period of 15 months. Although each increase in stimulation current caused a decrease in measured ventricular refractoriness, this resulted in only four arrhythmias. Only one arrhythmia was induced above 5 mA. These results suggest that this simple protocol using two extrastimuli and a single stimulation current of 5 mA will reliably identify most patients who have symptomatic ventricular arrhythmias.

Adolescent↗
PubMed1987

Dissociation of in vitro sensitivities of glucose transport and antilipolysis to insulin in NIDDM.

It is unclear from previous studies whether qualitative or only quantitative differences exist in insulin action in adipocytes obtained from obese subjects with non-insulin-dependent diabetes mellitus (NIDDM) when compared with equally obese nondiabetic subjects. In addition, the role of changes in insulin binding as a cause of insulin resistance in NIDDM is still controversial. We compared the sensitivities of glucose transport and antilipolysis to insulin and measured insulin binding in abdominal adipocytes obtained from 45 obese nondiabetic (% fat, 41 +/- 1), 25 obese diabetic (% fat, 40 +/- 1), and 15 nonobese (% fat, 30 +/- 1) female southwestern American Indians. Compared with the nonobese group, the sensitivities of glucose transport and antilipolysis were reduced in both the obese nondiabetic and obese diabetic groups. Compared with the obese nondiabetic subjects, the ED50 for stimulation of glucose transport was higher in the obese patients with NIDDM (171 +/- 38 vs. 92 +/- 10 pM, P less than 0.005). In contrast, the ED50s for antilipolysis were similar in obese diabetic patients (32 +/- 6 pM) and obese nondiabetic subjects (27 +/- 3 pM). No difference was found in insulin binding in patients with NIDDM when compared with the equally obese nondiabetic subjects. These data indicate 1) the mechanism of insulin resistance differs in NIDDM and obesity, and 2) the selective loss of insulin sensitivity in NIDDM precludes changes in insulin binding as a cause of insulin resistance in this disorder.

Adipose Tissue↗
PubMed1987

Effects of joint pathology on muscle.

The muscle wasting associated with joint damage may be highly selective; knee disorders produce quadriceps wasting but little change in the size of the hamstrings. This causes isolated quadriceps weakness, so predisposing to a position of knee flexion. Nociceptors and other receptors in and around the joint can have flexor excitatory and extensor inhibitory actions. At the knee, these receptors are likely to excite hamstrings and inhibit quadriceps. Although other actions could occur, quadriceps inhibition may be favored by a position of knee extension. Quadriceps inhibition will weaken voluntary contraction, reduce tone, and contribute to wasting of the muscle, further predisposing to a position of knee flexion. The potency of quadriceps inhibition may be considerable, even in the absence of perceived pain. A small, apparently trivial effusion (or even a clinically undetectable effusion) may cause important inhibition. In order to improve the orthopedist's ability to prevent flexion contracture of the injured or operated joint, he must look not only for ways of reducing joint pain, but also for ways of preventing activity in other joint afferents. For example, he must consider the possible effects of joint position, intraarticular pressure, suture-line tension, and afferent blockade.

Animals↗
PubMed1986

Familial dependence of the resting metabolic rate.

Human obesity is known to be a familial disorder. We studied 130 nondiabetic adult southwestern American Indians (74 men and 56 women) from 54 families to determine whether the resting metabolic rate, as measured by indirect calorimetry, is a familial trait that is independent of individual differences in fat-free mass (estimated mass of metabolically active tissue), age, and sex. We found that most of the variance in the resting metabolic rate (83 percent, P less than 0.0001) was accounted for by three covariates--fat-free mass, age, and sex--and that fat-free mass was the most important determinant. Family membership accounted for an additional 11 percent (P less than 0.0001) of the variance in the resting metabolic rate. Thus, resting metabolic rate is a familial trait in this population, and it is independent of differences in fat-free mass, age, and sex. We also found that persons from families with lower resting metabolic rates were no more obese than persons from families with higher metabolic rates. This finding may be partly explained by the close correlation between fat-free mass and percentage of body fat (r = 0.81, P less than 0.0001), which indicates that the resting metabolic rate, as adjusted for fat-free mass, is already partly adjusted for obesity. Only prospective studies will elucidate whether the familial dependence of the resting metabolic rate is a contributing mechanism to the familial predisposition to obesity.

Adolescent↗
PubMed1986

Dopamine antagonist haloperidol decreases substance P, substance K, and preprotachykinin mRNAs in rat striatonigral neurons.

Rat genomic clones were used to quantitate preprotachykinin mRNAs in the rat basal ganglia, while the tachykinin peptide products substance P and substance K were measured by radioimmunoassay. Administration of the dopamine antagonist (antipsychotic) drug haloperidol significantly decreased substance P, substance K, and both alpha (substance P encoding) and beta (substance P/substance K encoding) preprotachykinin mRNAs, suggesting a drug-induced decrease in striatonigral tachykinin biosynthesis. The time course for decreased preprotachykinin mRNAs and tachykinins apparently parallels the period of maximum risk for the development of certain antipsychotic drug-induced extrapyramidal side effects seen clinically. Tachykinin interaction with dopamine neurons may play an important role in the modulation of basal ganglia function.

Animals↗
PubMed1986

A study of lipid effects on the digoxin immunoassay and on the binding to and activity of Na+/K+-ATPase.

The present study has examined the cross-reactivity of fatty acids and mono- and di-glycerides in the fluorescence polarization immunoassay for digoxin. The ability of these compounds to inhibit 86Rb uptake by the erythrocyte as well as their ability to displace 3H-ouabain from membrane-bound dog kidney ATP-ase was also assessed. Some unsaturated fatty acids (palmitoleic, palmitelaidic, oleic, linoleic, linolelaidic, linolenic, gamma-linolenic and arachidonic) were found to cross-react significantly in the digoxin immunoassay and to inhibit 3H-ouabain binding to membrane-bound Na+/K+-ATPase. Of the monoglycerides studied mono-11-eicosenoin was found to cross-react in the digoxin immunoassay, inhibit red cell 86Rb uptake and displace 3H-ouabain from its receptor, membrane-bound Na+/K+-ATPase. Two other monoglycerides, 1-monolinoleoyl and 1-monolinolenoyl glycerides, were able to displace 3H-ouabain from membrane-bound Na+/K+-ATPase, but had no effect on the digoxin immunoassay or on red cell 86Rb uptake.

Animals↗
PubMed1986

Exercise physiology in geriatric practice.

Between now and the end of the century, we can expect a 45% increase in the proportion of the population aged 85 and over. The age-related loss of muscle mass and diminishing exercise tolerance mean that a large and increasing number of elderly people will be living at or near 'thresholds' of physical ability, needing only a minor intercurrent illness to render them dependent. Although much of the decline is obligatory, the effects of physical training are much the same, proportionally, in old age as in youth. Not only can exercise reverse the effects of immobilization, it can readily produce a further 10 to 20% improvement in strength and aerobic power, effectively postponing functionally important thresholds for some 10 to 20 years. There is an urgent need for close collaboration between exercise physiologists and geriatric clinicians. The relationship between disability in activities of daily living and age-related impairment of physical performance is especially ripe for study.

Activities of Daily Living↗