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Biomedical subjects

J Mills

Publications and source records attributed to J Mills.

At least 289 records · Page 16Linked to original sources
PubMed1979

Direct determination of luminal diameter changes in intrapulmonary airways.

A method is described for the direct measurement of changes in luminal diameter at all levels of the airway. Using this method it was found that (i) abrupt bronchiolar collapse occurred in the preterminal and terminal bronchioles once the luminal diameter was reduced to a critical level: (ii) decreased temperatures resulted in airway narrowing which was reversed by increasing the temperature to above 25 degrees C; as a rule, airway narrowing followed a cranial to caudal direction, and higher concentration of a drug being required to close the peripheral airways; (iii) bronchodilators except Carbuterol had no effect on resting bronchial tone or on acetylcholine-induced constriction in the absence of alpha-adrenoceptor blockade; (iv) at 35 degrees C rhythmic waves (frequency 6--20/min) were observed; these waves travelled from the periphery in a cranial direction.

Action Potentials↗
PubMed1979

Effects of Sendai virus infection on function of cultured mouse alveolar macrophages.

Cultured mouse alveolar macrophages supported the growth of Sendai virus (murine parainfluenza I virus), as measured by both a 10-fold increase in extracellular virus titers and development of viral antigens on most of the cells. Synthesis of virus continued for at least 1 month without cytopathic effects. Macrophage phagocytic activity for Candida, Staphylococcus epidermidis, and opsonized erythrocytes remained unaffected by the infection, and the ability of the cells to kill S. epidermidis and S. Aureus was also unchanged. The defects in alveolar macrophage function observed in Sendai-infected mouse lungs probably are not due to a direct effect of the virus on macrophage function.

Animals↗
PubMed1979

Pneumocystis carinii, Toxoplasma gondii, Cytomegalovirus and the compromised host.

Pneumocystis carinii and Toxoplasma gondii are the two major parasitic protozoan pathogens in the immunocompromised host. Both organisms cause latent infection in humans and many animals. Cats are the definitive hosts for toxoplasmosis; the animal vector for pneumocystis (if any) has not been defined. Toxoplasma is an obligate intracellular parasite, whereas the available evidence suggests that Pneumocystis carinii exists primarily extracellularly. In compromised hosts, pneumocystis infection usually involves only lungs, whereas toxoplasma causes a generalized infection with encephalitis being the principal clinical manifestation. Both types of infection are treated with combinations of folate antagonists (trimethoprim or pyrimethamine with sulfonamide). Both parasites are associated with cytomegalovirus infection in immunosuppressed hosts, an association which may be due to symbiosis between parasites, or to an additive immunosuppressive effect of dual infection on the hosts.

Adolescent↗
PubMed1979

The effect of beta-glucuronidase and chitinase on the cell wall of Aspergillus niger and Aspergillus fumigatus.

The effects of beta-glucuronidase and chitinase have been tested on the hydrolysis of the cell walls of the economically important fungi, Aspergillus niger and Aspergillus fumigatus. The extent of wall hydrolysis was measured by assaying for total reducing sugars, N-acetyl sugars and protoplast production. Maximum reducing sugar release was attained after 40 min incubation, both with beta-glucuronidase supplemented with chitinase and beta-glucuronidase alone, whereas N-acetyl sugar release reached a maximum at 80 min incubation. beta-Glucuronidase was effective in releasing protoplasts from both species of Aspergillus. This release was enhanced by adding chitinase to the incubation medium at 0 and 20 min, but with addition at 60, 80 and 100 min increase in protoplast yield was much reduced. The results of re-incubation experiments with chitinase suggest that this enzyme may in some way be inhibited during the later stages of incubation. Pronase used in combination with beta-glucuronidase slightly enhanced protoplast release.

Aspergillus fumigatus↗
PubMed1978

Growth of human tumour cell colonies from biopsies using two soft-agar techniques.

Two techniques for growing colonies of human tumour cells in soft agar have been applied to cell suspensions derived from fresh tumour tissue from 48 patients. Colonies were obtained in 31 cases, with plating efficiencies between 0.01 and 15%. In 11 cases the plating efficiencies were 1% or above. There was evidence that some categories of tumour grew more readily than others under these conditions. The potential applications of the methods to clinical and experimental oncology are discussed.

Agar↗
PubMed1978

An in vitro colony assay for human tumours grown in immune-suppressed mice and treated in vivo with cytotoxic agents.

An in vitro agar colony technique has been developed for the growth of tumour cells taken directly from human tumours grown in immune-suppressed mice. The novel feature of the technique is the addition of a replenishable liquid phase which permits the maintenance of relatively slowly growing cells. A number of different xenografted tumours have been cultured successfully in this system, with red blood cells added to the agar and using 5% O2 in the gas phase. The technique has been used to assay cell survival in tumours treated in vivo with cytotoxic agents, and examples are given of survival curves obtained from a pancreatic tumours irradiated with gamma-rays and a colonic tumour from mice treated with cyclophosphamide. The results obtained by this in vitro method are in agreement with those from the agar diffusion chamber technique. This culture method has also been successfully used for the growth of cells taken directly from human tumour biopsy samples obtained in the clinic.

Animals↗
PubMed1978

In vitro radiation response of cells from four human tumors propagated in immune-suppressed mice.

Two recently developed clonogenic assays for human tumor cells have been used to measure the in vitro radiation cell survival of four human tumors, a pancreatic carcinoma, a colonic carcinoma, an oat cell carcinoma of the lung, and a melanoma, propagated as xenografts in immune-suppressed mice. The slopes and shoulders of the survival curves for the first three tumors were all similar with Do's, respectively, of 94, 100, and 131 rads and with Dq's, respectively, of 8, 44, and 41 rads, However, melanoma cells from the fourth tumor had a survival curve that differed from those of the other three, both in having a wider shoulder with a Dq of 216 rads and in having a shallower slope with a Do value of 183 rads. It is suggested that the wide shoulder to the melanoma cell survival curve may in part explain the poor response to small fractionated doses of radiotherapy usually observed clinically for this tumor type. However, the data from the other three tumors suggest that differences in radiotherapeutic response seen in the clinic for these tumors cannot be attributed to differences in intrinsic radiosensitivity of the tumor cells.

Animals↗
PubMed1977

Role of cardiac catheterization in infective endocarditis.

The benefits and hazards of catheterization and angiography were evaluated in 19 patients with acute aortic and/or mitral endocarditis and heart failure. In 14 patients (74%), the bedside diagnosis of valvular insufficiency and heart failure was proved correct. In three patients with both aortic and mitral valve disease, angiography (without hemodynamic measurements) was necessary to clarify the diagnosis. Angiography detected four aortic aneurysmal erosions that were unsuspected clinically, but missed three others. After angiography, heart failure worsened in two patients with severe progressive aortic insufficiency and one died. Thus, catheterization-angiography was of greatest value if more than one left-sided valve lesion was present, if extravalvular diseases mimicked heart failure, or if extravalvular infection was present. Patients with isolated, clear-cut mitral insufficiency usually do not need these diagnostic procedures, and they are probably contraindicated in patients with severe aortic regurgitation with rapidly progressing heart failure.

Adult↗
PubMed1976

Enhancement studies on algae and isolated chloroplasts. Part II. Enhancement of oxygen evolution in intact chloroplasts.

Intact isolated chloroplasts were shown to exhibit a characteristic three-phase pattern of development of oxygen evolution activity. The first phase, Phase I, appeared to be an equilibration phase in which the isolated chloroplasts adapted to the conditions on the electrode surface. It was characterised by a rapidly increasing rate of oxygen evolution accompanied by decreasing enhancement signals. The second phase, Phase II, was an intermediate phase in which the rate of oxygen evolution was maximal and no enhancement was observed. In the last phase, Phase III, the rate of oxygen fell again, normal enhancement was still missing, but the samples appeared to undergo slow adaptive changes closely related to the State I-State II changes previously reported for whole cell systems. The concentrations of Mg2+ within the chloroplast were shown to play an important role in the control of the development of both the oxygen evolution and enhancement signals. It was shown how these signals could be explained in terms of a model that was consistent with that developed in Part I of this investigation to account for the variability of enhancement of the alga Chlorella pyrenoidosa.

Chlorella↗
PubMed1976

Effectiveness of nurse triage in the emergency department of an urban county hospital.

The effectiveness of patient triage by a specially trained registered nurse in the emergency department of an urban county hospital, San Francisco General Hospital, was evaluated over a three-month period. Ambulatory patients thought to have nonemergent illnesses were directed to the Walk-In Service for physician evaluation and treatment; the remainder were seen in the Emergency Service. In three months, 11,329 patients registered for care, and 4,150 (37%) were referred to the Walk-In Service. Of the 77 admitted patients, six were thought to require treatment within a few hours, 67 within hours to days, and four were considered elective admissions. There were no deaths. Error in triage was about equally divided between mistaken diagnosis and underestimated severity of illnes. The overall accuracy of triage was 98%.

Adolescent↗
PubMed1976

Serratia marcescens endocarditis: a regional illness associated with intravenous drug abuse.

From 1969 to 1974, 19 cases of Serratia marcescens endocarditis were observed in the San Francisco Bay Area. Seventeen patients were intravenous drug users, and Serratia caused 14% of all addict-associated endocarditis in San Francisco. Serratia strains were nonpigmented and had typical antibiotic sensitivities, except that 9 of the isolates exhibited colonial variation, with each variant having different antibiotic sensitivities. Aortic or mitral valves were involved in 13 patients, and heart failure developed in 9 of these. Twelve patients had embolic episodes to brain, iliofemoral arteries, or lung. Five of 6 patients with tricuspid valvulitis were cured by antibiotics either with (1) or without excision of the valve. All 12 patients with aortic or mitral valvulitis treated medically died; 11 had unremitting sepsis. Aortic valve replacement and antibiotics were effective in 1. Gentamicin combined with either carbenicillin or chloramphenicol was the most effective treatment regimen.

Adult↗