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Biomedical subjects

J Hay

Publications and source records attributed to J Hay.

At least 145 records · Page 8Linked to original sources
PubMed1991

[Cardiopulmonary risk factors in patients with sleep apnea].

Since the interaction between disorders of the respiratory coordination and cardiovascular or cardiopulmonary regulation is still largely unknown the intention of the present investigation is to point out the coincidence of cardiac arrhythmias, such as premature ventricular capture (PVC) beats and conduction blocks, with obstructive sleep apnea (OSA). For the first time a group of more than 300 patients with suspected OSA is examined concerning risk factors and frequent diagnoses as obesity, hypertension, coronary heart disease (CHD), heart insufficiency, chronic obstructive pulmonary disease (COPD), and daytime hypoxaemia. Summarizing the results of lung function test, blood gas analysis, strain-ECG, Holter-ECG and inductive plethysmography with oxygen partial pressure measurement by ambulatory work-up the following statements can be made: PVC beats occurring markedly during sleep give hints for OSA being the underlying cause, especially if the patients are young and overweight. Hypoxaemia increasing during the apnea episodes should be considered as one possible pathogenetic mechanism. Second- and third degree conduction blocks and sinus arrest coincident very often with OSA. They suggest to be life-limiting factors the more so since they often go along with CHD or heart insufficiency. Systemic arterial hypertension and overweight have the highest prevalence in OSA, signs for heart insufficiency and daytime hypoxaemia are also significantly more frequent than in non-OSA patients. We could find no hints for direct pathogenetic coherence between CHD and OSA or between COPD and OSA, nevertheless pronounced nocturnal changes in blood gases and intrathoracic hemodynamics have important influence on the cardiopulmonary and cardiovascular system, as partly illuminated in other more pathogenetic oriented studies by the present time.

Arrhythmias, Cardiac↗
PubMed1991

Acinic cell carcinoma of the parotid gland: review and management.

The purpose of this retrospective review is to study the management of a rare malignant tumor of the parotid gland, the acinic cell carcinoma. Incidence, pathology, clinical findings, and diagnosis are reviewed. Twenty-five patients were seen at the British Columbia Cancer Agency (BCAA) for initial treatment, recurrent disease or follow-up during the period 1958-1990. Twenty-two acinic cell carcinomas (ACC) occurred in the parotid gland. Surgical treatment regimens for parotid ACC ranged from local excision to radical excision. Local excision is not advised but superficial parotidectomy alone appears to have been adequate treatment for small superficial tumors. Eleven of 22 patients received radiotherapy. Indications for adjuvant postoperative radiotherapy are given. Nine patients with primary tumors treated with combined therapy are alive and disease-free with a mean follow-up of 10.7 years. Postoperative radiotherapy appears to be effective in eradicating microscopic residual disease although long-term follow-up is necessary to make these results clinically significant.

Adolescent↗
PubMed1990

Ultrastructural immunocytochemistry of the intact tissue cyst of Toxoplasma in the brains of mice with congenital toxoplasmosis.

Electron immunocytochemistry, using rabbit polyclonal anti-Toxoplasma IgG as the primary layer in immunogold staining, was used to assess the distribution of Toxoplasma antigen within, and in relation to, intact tissue cysts in brain tissue from mice with congenital toxoplasmosis. Toxoplasma antigen was widely distributed in the matrix of the cyst, being most concentrated in the proximity of the inner surface of the parasitophorous vacuole membrane (PVM). Relatively little Toxoplasma antigen was detected directly associated with cystozoites. Small amounts of antigen were detected within the host cell components exterior to the PVM and in the host neuropil immediately adjacent to the tissue cyst.

Animals↗
PubMed1990

Social interactions of mice with congenital Toxoplasma infection.

The social interactions of male mice with subclinical congenital Toxoplasma infection towards their uninfected counterparts was assessed using a procedure based on the subdivision of behaviour into element groups. Infection had no effect on behavioural elements not directly associated with interaction. However infection was found to increase companion investigation as well as a number of elements directly associated with aggression. There was a complementary decrease in elements associated with flight behaviour. These findings suggest that congenital infection with Toxoplasma renders mice less cautious towards uninfected conspecifics and increases the tendency of adult male mice towards territorial aggression.

Aggression↗
PubMed1990

Ivermectin and coagulation: an in vitro study.

The prothrombin time, partial thromboplastin time with kaolin, and thrombin clotting time of plasma derived from healthy human volunteers were unaltered after in vitro addition of therapeutic concentrations (20-90 ng ml-1) of ivermectin. No difference in these coagulation tests, relative to untreated controls, was observed after 12 hours' incubation with the drug.

Adult↗
PubMed1990

The effect of pentamidine salts on the NADPH-dependent oxidase of stimulated neutrophilic granulocytes.

Both pentamidine isethionate and pentamidine mesylate induced a depression in activity of the NADPH-dependent oxidase system of stimulated human neutrophilic granulocytes. This drug-induced effect occurred at concentrations of 0.7, 1.1 and 1.5 mg/l, values within the therapeutic range after parenteral administration of a standard dose of either pentamidine salt, and was dose-related. There was no significant difference between the two salts with regard to this suppression in neutrophilic granulocyte function. The reduced activity of the NADPH-dependent oxidase system, after incubation with pentamidine salts, may be associated with the previously observed depression in candidacidal capacity of human neutrophilic granulocytes treated with these drugs.

Adult↗
PubMed1990

The glycoprotein products of varicella-zoster virus gene 14 and their defective accumulation in a vaccine strain (Oka).

Many characteristics of the putative protein encoded by varicella-zoster virus (VZV) open reading fram (ORF) 14 indicate that it is a glycoprotein, which has been designated gpV. To identify the protein products of the gene, the coding sequences were placed under the control of the vaccinia virus p7.5 promoter and recombinant vaccinia viruses were constructed. Heterogeneous polypeptides with molecular weights of 95,000 to 105,000 (95K to 105K polypeptides) were expressed in cells infected by a vaccinia virus recombinant (vKIP5) containing ORF 14 from VZV Scott but were not expressed by control vaccinia viruses. These polypeptides were recognized by antibodies present in human sera that contained high levels of anti-VZV antibodies. Conversely, antisera raised in rabbits inoculated with vKIP5 reacted specifically with heterogeneous 95K to 105K polypeptides present in VZV Scott-infected but not uninfected cells; these polypeptides show a patchy plasma membrane fluorescence pattern in VZV Scott-infected cells. These same antisera neutralized VZV strain Scott infectivity in the absence of complement. Endoglycosidase F treatment of isolated gpV polypeptides and tunicamycin treatment of cells infected with the vKIP5 recombinant indicated that the polypeptides were glycosylated. Three sets of data imply that the VZV strain Oka, which has been used to produce a live attenuated virus vaccine, accumulates low levels of gpV polypeptides relative to wild-type strains: (i) blocking of antibodies in human sera with excess VZV Oka-infected cell antigen yielded residual antibodies which were reactive with the 95K to 105K gpV polypeptides expressed in cells infected by VZV strain Scott and by the vKIP5 vaccinia virus recombinant, but not with Oka-infected cell polypeptides; (ii) antisera raised to vKIP5 detected very low levels of reactive polypeptides made in VZV Oka-infected cells and neutralized VZV Oka virus much less efficiently than VZV Scott; and (iii) comparisons of the reactivity of sera from live attenuated virus vaccine vaccinees with sera derived from patients recovering from wild-type infections indicated greatly reduced levels of gpV-specific antibodies in some vaccinees.

Animals↗
PubMed1989

Pathologic findings in total esophagectomy specimens after intracavitary and external-beam radiotherapy.

Pathologic findings in 21 esophagectomy specimens from patients having preoperative combined intracavitary radiotherapy (ICR) and external-beam radiotherapy (EBR) are described. Eleven patients received 1500 cGY ICR and 4000 cGy EBR (Group 1) and ten patients received 1500 cGy plus 2000 to 3000 cGy EBR (Group 2). Effectiveness of radiotherapy was expressed as the ratio between depth of radiation effect and depth of tumor invasion. Depth was expressed as one of four levels: Level I, not deeper than the muscularis mucosa; Level 2, involving but not deeper than submucosa; Level 3, involving but not deeper than muscularis propria; and Level 4, involving periesophageal soft tissue. The depth of radiation damage to tumor cells was comparable between the two groups. However, residual tumor was present in the periesophageal tissue in only one of 11 patients after high-dose EBR compared to of ten patients with lower dose EBR (P less than 0.01, chi-square test). A ratio of one between radiation effect and depth of tumor invasion was present in six patients receiving high-dose EBR and one patient receiving lower dose EBR (P less than 0.05). The authors conclude that ICR combined with EBR affords good local tumor control in the majority of patients. Higher doses of EBR give a better radiation effect in deeper layers of the esophageal wall. The ratio between depth of radiation effect and tumor invasion provides a simple and objective approach to the pathologic analysis of esophagectomy specimens.

Adenocarcinoma↗
PubMed1989

Incidence of Toxoplasma infection in a population of European starlings Sturnus vulgaris from central England.

A sample of European starlings, Sturnus vulgaris, culled from a communal roost in a city in Central England, was examined for infection with Toxoplasma. Eleven (8%) of 133 birds were confirmed as infected after horizontal passage of brain homogenate through mice. Serological examination, using the indirect and direct agglutination tests, proved unsatisfactory for screening starlings for Toxoplasma infection. If the proportion of starlings infected with Toxoplasma in this sample is representative of the population as a whole, then this bird could play an important role in the maintenance of the infection in urban environments.

Agglutination Tests↗
PubMed1989

The effect of pentamidine salts on the in-vitro responses of neutrophilic granulocytes.

Therapeutic concentrations (0.3-1.5 mg/l) of pentamidine isethionate and pentamidine mesylate, obtained after parenteral administration of the drugs, did not influence neutrophilic granulocyte adherence, random and chemotactic migration or phagocytosis of Candida albicans spores in vitro. At concentrations of 0.7, 1.1 and 1.5 mg/l, the ability of neutrophilic granulocytes to kill C. albicans spores was depressed (P less than 0.001); at all concentrations used, their ability to reduce nitroblue tetrazolium was decreased (P less than 0.001). There was no significant difference between the drugs with regard to these impairments in neutrophilic granulocyte function. It is likely that pentamidine salts inhibit superoxide radical formation in the stimulated neutrophilic granulocyte and that this dysfunction leads to depressed intracellular killing of C. albicans spores.

Adult↗
PubMed1989

The effect of pentamidine salts on the respiratory burst of human neutrophilic granulocytes.

Therapeutic concentrations (0.3-1.5 mg/l) of pentamidine isethionate and pentamidine mesylate, obtained after parenteral administration of either drug, did not affect oxygen consumption in the stimulated neutrophilic granulocyte. At concentrations of 0.7, 1.1 and 1.5 mg/l, superoxide production, hydrogen peroxide production, myeloperoxidase (MPO)-mediated iodination and hexose monophosphate shunt activity were suppressed relative to untreated cells (P less than 0.001 in each case). The depression in each activity was dose-related. There was no significant difference between the drugs with regard to these impairments in neutrophilic granulocyte function. This lowered respiratory burst activity, which would lead to a depression of MPO-dependent and MPO-independent processes in stimulated neutrophilic granulocytes, may be due to drug induced dysfunction of NADPH-oxidase.

Granulocytes↗