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Biomedical subjects

J Green

Publications and source records attributed to J Green.

At least 577 records · Page 32Linked to original sources
PubMed1985

Severe pancytopenia due to marked marrow fibrosis associated with angioimmunoblastic lymphadenopathy.

A patient with angioimmunoblastic lymphadenopathy (AILD) is presented. Manifestations of the disease appeared after short-term treatment with oxprenolol hydrochloride. Following treatment with prednisone, the patient remained in remission for 25 months. The disease relapsed following reuse of oxprenolol hydrochloride. Severe pancytopenia due to bone marrow involvement by AILD and myelofibrosis led to a fatal outcome. The association of AILD and myelofibrosis has been rarely encountered and is hereby discussed. In addition, the possible relationship between AILD and oxprenolol hydrochloride is considered.

Angina Pectoris↗
PubMed1985

The tussive effect of hyperpnea with cold air.

The tussive and bronchoconstrictive effects of hyperpnea with cold air (HCA) are described in 3 patients with exercise-induced cough, 7 volunteers with exercise-induced cough, and 7 asymptomatic volunteers. Cough associated with HCA exceeded baseline cough in each of the patients and volunteers with exercise-induced cough and in all but one of the asymptomatic volunteers. The time course of cough was similar in each group. Maximal cough frequency occurred during the first 5 min after HCA and persisted to a much lesser degree during the ensuing 26 min. The time course of bronchoconstriction was similar to that of cough, with maximal decrements in specific airway conductance measured 5 min after HCA. Pretreatment with albuterol blocked HCA-induced bronchoconstriction but had no effect on HCA-induced cough. No subject in any of the 3 groups was hyperreactive to methacholine aerosols. In subjects who are nonhyperreactive to methacholine aerosols, HCA has a characteristic, reproducible, and predictable tussive effect. Thus, HCA may be a useful tool for investigating the mechanism of cough and for evaluation of antitussive drugs.

Adult↗
PubMed1985

Homeostatic regulation of bronchomotor tone by sympathetic activation during bronchoconstriction in normal and asthmatic humans.

It has been assumed previously that the sympathetic nervous system (SNS) serves to antagonize bronchoconstrictor stimuli. To assess the homeostatic regulatory effect elicited by exogenously induced bronchoconstriction, we studied the effect of inhaled methacholine on the SNS response in 12 normal and 9 asthmatic humans. Exogenous SNS response was assessed as change in plasma epinephrine and norepinephrine concentrations from basal levels during inhalation challenge. A 74 +/- 3% decrease in specific airway conductance (SGaw) (p less than 0.001) was induced in normal subjects and a 78 +/- 7% decrease in asthmatics by methacholine challenge (p less than 0.001). Neither plasma epinephrine nor norepinephrine increased significantly from basal concentrations in normal or asthmatic subjects after maximal challenge (p greater than 0.33). To determine if physiologically achievable epinephrine concentrations potentially could modulate bronchoconstriction, the effect of intravenously infused epinephrine was measured in 11 of these subjects. After the highest dose of methacholine, a 15-min intravenous infusion of epinephrine (0.06 micrograms/kg/min) caused an 85 +/- 7% increase in SGaw in normal subjects (p less than 0.02). In asthmatics, a 319 +/- 68% increase in SGaw (p less than 0.002) was observed with similar changes in plasma epinephrine. Plasma epinephrine concentrations after infusion were comparable to those obtained in 4 normal and 1 asthmatic subject undergoing 60-degree, head-up tilt 1 h after volume depletion with intravenously administered furosemide. We conclude that physiologic concentrations of epinephrine can modulate moderately severe bronchoconstriction. However, the SNS does not regulate bronchomotor tone during mild to moderate bronchoconstriction.

Adolescent↗
PubMed1985

Reversible acute interstitial nephritis associated with indomethacin.

Nonsteroidal, anti-inflammatory drugs have been implicated in causing acute renal failure of several distinct patterns. We report a case of reversible acute renal failure associated with indomethacin therapy. Renal function recovered upon cessation of indomethacin treatment. Renal biopsy disclosed the presence of tubulointerstitial nephritis which was thought to have been responsible for the acute renal failure in this patient. Following presentation of this unusual side effect within the wide spectrum of renal and electrolyte disorders related to nonsteroidal, anti-inflammatory agents, we recommend that kidney function indices should be frequently tested in patients receiving indomethacin.

Acute Kidney Injury↗
PubMed1985

Male homosexuality and sexual problems.

Homosexual men are increasingly seeking help with sexual problems. A few seek to change their orientation and there is evidence that, for some people at least, this is possible. However the major reason for seeking help is sexual dysfunction which is treatable in homosexual men in the same way as in heterosexuals.

Ejaculation↗
PubMed1984

Relation of respiratory water loss to coughing after exercise.

Exercise has been shown to result in bronchoconstriction, the extent of which is related to respiratory heat loss. Some normal subjects report coughing after exercise, and to determine whether this might also be related to respiratory heat loss, we monitored cough frequency after hyperpnea with air of varying temperature and water content in seven such subjects. Hyperpnea with fully saturated air at 37 degrees failed to provoke coughing and was not associated with heat loss or water loss. Hyperpnea with dry air at 37 degrees C resulted in more water loss (P less than 0.0005), less heat loss (P less than 0.01), and more coughing (P less than 0.001) than hyperpnea with subfreezing air. Hyperpnea with ambient air was associated with a similar cough frequency and water loss but with less heat loss (P less than 0.001) than hyperpnea with subfreezing air. There was a direct relation between cough frequency and respiratory water loss but no consistent relation between cough frequency and respiratory heat loss. This study indicates that coughing after hyperpnea with poorly conditioned air is related to the overall rate of respiratory water loss. Since strenuous exercise is associated with marked hyperpnea, coughing after exercise may also result from respiratory water loss.

Adult↗
PubMed1984

Comparison of the hypotensive effects of streptokinase-(human) plasmin activator complex and BRL 26921 (p-anisoylated streptokinase-plasminogen activator complex) in the dog after high dose, bolus administration.

In view of current interest in the possibility of rapid, high-dose administration of thrombolytic agents by the intravenous route in patients with coronary thrombosis (AMI), a study of this technique was carried out in the dog. Streptokinase-(human) plasmin activator complex (SK-Pm) and BRL 26921 (p-anisoylated streptokinase-(human) plasminogen activator complex) were each given at equivalent doses (28,500 IU/kg and 800 micrograms/kg respectively) to groups of beagle dogs by rapid injection over 10 sec and their effects on blood pressure, plasmin formation and kallikrein production were compared over the next 3h. SK-Pm produced, within 1-3 min, a pronounced hypotensive effect that was kinetically related to a rapid and steep rise in systemic plasmin and kallikrein concentrations. BRL 26921 had no hypotensive effect, the rise in plasmin production was slower and the rate and extent of kallikrein formation was significantly less than in the SK-Pm group.

Animals↗
PubMed1984

Plasma vitamin E values in the newborn.

Plasma vitamin E values of newborn infants in a Coloured population of Cape Town have been determined. The mean plasma alpha-tocopherol value was 3,2 +/- 0,8 mg/l. A significant correlation between the plasma alpha-tocopherol level and plasma total lipid content (r = 0,45; P less than 0,001) and plasma cholesterol level (r = 0,65; P less than 0,001) has been found. However, maternal and neonatal plasma vitamin E levels were unrelated.

Adolescent↗
PubMed1984

An enveloped virus in stools of children and adults with gastroenteritis that resembles the Breda virus of calves.

Pleomorphic virus-like particles about 100 nm in diameter with a fringe of closely applied peplomers (7-9 nm in length) were observed by electron microscopy in the stools of 20 children and adults with gastroenteritis. In most of the samples no other viral or bacterial pathogens were detected. In form and under immune electron microscopy these virus-like particles resembled the Breda virus isolated from diarrhoeic calves. These objects may be a viral pathogen of humans.

Adult↗
PubMed1984

Acyl-enzymes as thrombolytic agents in dog models of venous thrombosis and pulmonary embolism.

A quantitative model of venous thrombosis in the beagle dog is described. The model was adapted to permit ageing of isolated experimental clots in vivo. A model of acute pulmonary embolism in this species is also described. In the venous thrombosis model, infusion of streptokinase (SK) or SK-activated human plasmin gave significant lysis but bolus doses of SK. plasmin complex were ineffective. Active site anisoylated derivatives of SK. plasminogen complex, SK-activated plasmin and activator-free plasmin were all active when given as bolus doses in both models. At lytic doses, the acyl-enzymes caused fewer side-effects attributable to plasminaemia than the corresponding unmodified enzymes.

Animals↗
PubMed1984

Studies on the polyglutamate specificity of methylenetetrahydrofolate dehydrogenase from pig liver.

Methylenetetrahydrofolate dehydrogenase, which is one of the activities of a trifunctional folate-dependent enzyme isolated from pig liver, displays an ordered bi-bi kinetic mechanism when methylenetetrahydropteroylmonoglutamate is used as the folate substrate [Cohen, L., & MacKenzie, R. E. (1978) Biochim. Biophys. Acta 522, 311-317]. We have studied the inhibition of this activity by a series of pteroylglutamates containing one to seven glutamyl residues. Inhibitors with one to four glutamyl residues exhibit a kinetically determined KD of about 56 microM for binding at the folate site of the enzyme, while inhibitors with five to seven glutamyl residues exhibit a KD of about 16 microM. These results suggest that folylpolyglutamates are bound to the trifunctional enzyme relatively weakly, with the major interaction involving the fifth glutamyl residue of the polyglutamate "tail". A free energy decrease of about 0.74 kcal (3.1 kJ) is associated with this interaction. The possibility of a swinging arm mechanism for the trifunctional enzyme is discussed. We have also measured the kinetic parameters Vmax and the Km values for NADP+ and the folate substrate associated with catalysis using a series of methylenetetrahydropteroylpolyglutamate substrates. The variation in these parameters with the length of the polyglutamate tail is small.

Animals↗
PubMed1984

Effects of intrahemispheric interference on reaction times to lateral stimuli.

Earlier work (Green, 1977) indicated that response by a given hand was slower when stimuli occurred in the visual half field ipsilateral to the body side of hand origin. It was hypothesized that this was due to interference between processing demands originating within the same hemisphere. The present experiments provide evidence regarding the relationship between such interference and the magnitude and type of processing demands. The eight experiments indicate that intrahemispheric interference affects a variety of tasks, including letter shape, letter name, or face matching. The results indicate that reduction in response processing demands reduces the interference. Evidence of interference appeared with a more demanding choice response, but not with a simpler go-no-go response. Manipulations hypothesized to reduce initial, perceptual stimulus processing demands did not reduce the magnitude of interference, possibly because the level of more central stimulus processing demands was still sufficient to interfere with response processing. Interference tended to be minimal on right-hand, match trials, which are hypothesized to involve reduced response processing and reduced central stimulus processing demands. Further investigation of the effects of stimulus processing demands is required.

Attention↗
PubMed1984

Vestibular stimulation and eye contact in autistic children.

Five autistic boys ages 5-1 to 5-10 were studied to determine whether stimulation of the macular receptors of the inner ear through linear motion influences the boys' eye contact with the investigators. The duration of eye contact was measured during linear motion on a motor-driven oscillator and on two hand-operated swings and compared to the duration of eye contact when the macular receptors were not stimulated. Because the boys varied in cooperation, the tests could not be performed using the same apparatus with each child; therefore results were analyzed separately for each child. Four of the five boys showed longer eye contact while on the motor driven oscillator (p less than .0005), and two of these also showed longer contact when on a manually operated swing (p less than .025). The fifth child resisted the use of the oscillator and did not show longer eye contact while on it (p greater than .05), but did so when on two different swings (p less than .005).

Autistic Disorder↗
PubMed1984

Subcellular localization and properties of partially purified dimethylamine and trimethylamine mono-oxygenase activities in Candida utilis.

By techniques involving differential centrifugation and specific precipitation with CaCl2, it was shown that dimethylamine and trimethylamine mono-oxygenase activities co-sediment with NADPH-cytochrome c reductase activity in sphaeroplast lysates of Candida utilis grown on trimethylamine as sole nitrogen source. Since the active fraction also contained low levels of cytochromes P-450 and P-420, it was concluded that the two amine mono-oxygenases are located in the smooth endoplasmic reticulum and thus end up in the microsomal fraction on cell fractionation. Ten to twenty-fold enrichment of mono-oxygenase specific activity could be achieved by separation of activity from soluble protein by centrifugation or gel filtration. Cell-free extracts prepared in the absence of FAD showed only very low mono-oxygenase activity for either substrate. Some activity could be restored by addition of flavin nucleotides: there was a fivefold stimulation by FAD and a fourfold stimulation by FMN. All trimethylamine mono-oxygenase activity was lost when a partially purified preparation containing both activities was incubated for more than 24 h at 0 degrees C, suggesting that separate enzymes are responsible for the oxidation of secondary and tertiary amines. The enzyme preparation oxidized a wide range of secondary alkylamines up to dibutylamine and tertiary alkylamines up to tributylamine. Primary amines, choline, di- and triethanolamine, spermine, spermidine and substituted anilines were not oxidized. NADH had a lower apparent Km value and higher Vmax value than NADPH. Secondary and tertiary alkylamines containing more than one kind of alkyl group gave more than one kind of aldehyde on oxidation. Stoicheiometry determinations showed a consumption of 1 mol NAD(P)H and 1 mol O2 per mol aldehyde formed. Carbon monoxide, cyanide, proadifen hydrochloride (SKF 525-A), mercurials and mercaptoethanol all inhibited both activities.

Candida↗
PubMed1984

Jaundice, the circulation and the kidney.

(Fig. 1) Cholemia per se (i.e. independent of parenchymal liver damage) causes a profound disturbance of systemic hemodynamics. This includes decrease in total peripheral vascular resistance, and possible impairment of left ventricular performance. These, in turn, lead to a decrease in effective blood volume, a tendency to hemorrhagic shock and prerenal failure. Early in the course of cholemia , the natriuretic effects of bile salts in the circulation may aggravate the hypovolemia. In marked contrast to the decrease in total peripheral vascular resistance, the regional vascular beds of the kidney and the brain constrict during cholemia . The combined effect of cholemia may thus lead to redistribution of cardiac output away from the kidney and the brain. When parenchymal liver damage complicates obstructive jaundice, the tendency to arterial hypotension is aggravated. The overall interrelationship between jaundice and circulatory homeostasis is depicted in figure 1.

Animals↗