Biomedical subjects

G Harvey

Publications and source records attributed to G Harvey.

At least 55 records · Page 3Linked to original sources

PubMed1991

Piperacillin/tazobactam in the treatment of serious acute soft tissue infection.

Twenty-five consecutive patients admitted to hospital with severe soft tissue infection were entered into an open trial designed to evaluate safety and efficacy of the drug combination tazobactam/piperacillin. The dosage regimen was 4 g piperacillin/500 mg tazobactam Q8H. There were twenty cases of uncomplicated cellulitis and five cases with associated abscess formation. These five cases required adjunctive surgical drainage. Mean duration of therapy was 7.6 days. No other antibiotics were administered unless treatment with the study drug failed. There were eight treatment failures, six related to the trial drug. Four patients developed an allergic response to the trial drug, necessitating a change of therapy. Three patients failed to respond; all three had acute cellulitis in association with peripheral vascular disease. Significant bacterial isolates were grown in thirteen patients; Group A streptococci in three, S. aureus in five, other pathogenic streptococci in four and coliforms or Ps. aeruginosa in five. The majority of isolates except the streptococci were resistant to piperacillin but all isolates except one strain of Ps. aeruginosa were susceptible to the combination. The combination is suitable for the treatment of serious soft tissue infection, but increased doses may be appropriate in infection at poorly perfused sites.

Adolescent↗

PubMed1989

[Isolated rectal ectasia: a rare cause of chronic constipation. Apropos of 2 cases].

We present two patients with intractable constipation, in which investigation revealed a huge rectal ectasia without apparent other anomaly. Findings at operation are similar to those observed in the focal ectasia of the terminal bowel that we have already described in some cases of low anal deformities. As long as the physiopathology of this anomaly is not elucidated, complete amputation of the rectum seems to be the treatment of choice.

Adolescent↗

PubMed1988

Search for multienzyme complexes of DNA precursor pathways in uninfected mammalian cells and in cells infected with herpes simplex virus type I.

Confirmatory evidence for the existence of a multienzyme complex of DNA precursor pathways in mammalian cells was obtained. Using neutral sucrose gradient centrifugation of cell lysates we found that at least five enzymes involved in DNA precursor metabolism in uninfected. S-phase BHK-cell fibroblasts cosediment at a common rate, indicative of a multienzyme complex. The enzymes include DNA polymerase thymidine kinase, ribonucleotide reductase, dihydrofolate reductase, and NDP-kinase. This complex was partially, but not completely, disrupted when lysates from GO-phase cells were centrifuged. Using lysates from cells infected with herpes simplex virus (HSV) type I some of the virus-induced ribonucleotide reductase and a minor proportion of the HSV-thymidine kinase cosedimented rapidly. The virus-induced DNA polymerase sedimented independently near the middle of the gradient, in contrast to the behaviour of the host polymerase. The enzyme associations observed were disrupted by NaCl or by inclusion of ethylenediamine tetraacetic acid during the cell lysis procedure, instead of the usual EGTA. These results indicate the importance of ionic forces in maintaining the enzyme complexes. The bulk of the DNA and the RNA present in the lysates did not sediment at the same rate as the complexes, showing that the enzymes were not simply adhering nonspecifically to these polyanions. Newly synthesised radiolabeled DNA (15 min pulse with [3H]thymidine) was not preferentially associated with the enzymes, but some functional DNA was evident in the enzyme complex fraction from the uninfected S-phase cells. DNA polymerase activity in this fraction did not require, nor was it stimulated by, exogenous "activated" DNA. Added DNA primer-template was required, however, for maximal activity of the polymerase in gradient fractions derived from GO-phase cells and from HSV-infected cells. No evidence for channeling of ribonucleotide precursors into DNA of permeabilized cells (uninfected or HSV-infected) was detected. Most rCDP was incorporated into RNA. In the uninfected, S-phase cells about 10 pmol/10(6) cells/90 min of rCDP residues was incorporated into DNA compared with 120 pmol/10(6) cells/90 min when radiolabeled dCTP was used. Nonradioactive dCTP present in equimolar concentration in the incubation with labeled rCDP did not, however, diminish the incorporation of label from the ribonucleotide. In permeabilized HSV-infected cells incorporation of radiolabel from rCDP into DNA was barely detectable.

Animals↗

PubMed1985

Papilloedema and respiratory failure.

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Female↗

PubMed1985

Effects of varying intensities of laser energy on articular cartilage: a preliminary study.

The effects of laser energy on articular cartilage were studied utilizing the neodymium YAG laser. Partial-thickness cartilage defects were surgically attempted in the femoral condyles of knee joints in guinea pigs. The defects were exposed to laser energy of varying intensities [group I, 25 J (5 W X 5 sec); group II, 75 J (15 W X 5 sec); group III, 125 J (25 W X 5 sec)]. A fourth group was studied, in which the defect was not lased. Animals were killed at weekly intervals from 1 to 6 weeks and the knee joints were subjected to histological analysis. At 5 weeks, the knees exposed to 25 and 75 J demonstrated a reparative process with chondral proliferation. The knees exposed to 125 J demonstrated fibrotic tissue and tissue necrosis that resulted in fibrosis. In the knees not exposed to laser energy, numerous foci of granulation tissue were present at all stages with the end point of healing being one of fibrosis with disorganized patchy cartilage islands.

Animals↗

PubMed1985

Diurnal variation in oxygen consumption of laboratory rats.

Oxygen consumption (VO2) was measured in Porton albino rats using a closed circuit apparatus. The groups studied were controls, cold-adapted animals, and those which had accumulated brown adipose tissue as a result of a cafeteria diet with a high energy content. It was possible to show in each group studied a difference in VO2 according to the time of day at which it was measured. This was consistent within each group studied. The diurnal variation shown (higher in the morning than in the afternoon) is characteristic of nocturnal animals. Measurement of VO2 then must be made within the same time-period or integrated over 24 h. Spurious correlations may otherwise occur.

Acclimatization↗

PubMed1985

The action of dopamine upon brown adipose tissue.

We increased the mass of interscapular brown adipose tissue in rats by dietary manipulation ("cafeteria" feeding), cold exposure, or by both. The animals were then used to determine the temperature response of the interscapular brown adipose tissue to dopamine or norepinephrine. These results, and the increase in blood glycerol values, were very similar for either catecholamine. These findings suggest that dopamine may have a role in releasing energy from brown adipose tissue similar to that of norepinephrine in the newborn infant.

Adipose Tissue, Brown↗

PubMed1984

Binding of environmental carcinogens to asbestos and mineral fibres.

A rapid method has been developed for measuring the binding capacity of asbestos and other mineral fibres for environmental carcinogens. Benzo(alpha)pyrene (B(alpha)P), nitrosonornicotine (NNN), and N-acetyl-2-aminofluorene (NAAF) were assayed in the presence of Canadian grade 4T30 chrysotile, chrysotile A, amosite, crocidolite, glass microfibres, glasswool, attapulgite, and titanium dioxide. Chrysotile binds significantly more carcinogens than the other mineral fibres. This binding assay is reproducible with coefficients of variation of less than 8% and 6% respectively for inter and intra assay. The influence of pH was also studied, and there is good correlation between the carcinogen binding and the charge of the tested mineral fibres. The in vitro cytotoxicity on macrophage like cell line P388D1 and the haemolytic activity of various mineral fibres were also measured; a good correlation was found between the binding capacity and the cytotoxicity of tested mineral fibres on P388D1 cells. These results give some explanations for the reported synergism between exposure to asbestos and the smoking habits of workers.

2-Acetylaminofluorene↗

PubMed1983

New technique for detection of changes in QRS morphology of ECG signals.

With the use of the electrocardiogram (ECG) as a prototype signal, a new technique was devised for detecting signals embedded in noise. Averaged "normal" digitized ECG signals formed a template to which subsequent ECG QRS complexes were compared. The difference between the averaged template signals and subsequent normal beats was white noise, whereas the difference between the template and ectopic beats consisted of nonrandom signal variation. The template to new signal comparison for the zero-, first-, second-, and third-order differences utilized an approximate F test. Accurate detection of abnormal signals associated with high- and low-frequency noise is accomplished with this method, and the practical clinical utility of the method is under study.

Arrhythmias, Cardiac↗

PubMed1982

Prostatic cancer, acid phosphatase, creatine kinase-BB and race: a prospective study.

To examine the effectiveness of prostatic acid phosphatase and creatine kinase-BB determinations in detecting prostatic cancer serum from 594 men more than 40 years was assayed for prostatic acid phosphatase with the thymolphthalein monophosphate substrate and a radioimmunoassay kit. Creatine kinase-BB levels also were measured with a radioimmunoassay kit. Patients with benign prostatic hyperplasia had higher prostatic acid phosphatase levels than normal controls. Accordingly, to avoid a high incidence of false positives in patients with benign prostatic hyperplasia the 92.5 percentile level of the patients with benign prostatic hyperplasia (3.9 ng./ml.) was chosen as the upper limit of normal. With this critical value elevated prostatic acid phosphatase levels were observed in 6 per cent of the patients with clinical stage A disease, 8 per cent with stage B, 35 pr cent with stage C and 68 per cent with stage D. The radioimmunoassay was no more effective than the enzymatic assay in detecting prostatic cancer. A correlation between prostatic acid phosphatase levels and patient race was observed, with 80 per cent of the black patients with extracapsular prostatic cancer having elevated prostatic acid phosphatase levels compared to 34 per cent of the white patients with similar stage disease. Creatine kinase-BB was elevated only in patients with advanced disease and was of little value in the diagnosis of prostatic cancer.

Acid Phosphatase↗

PubMed1981

Interaction of aromatic dyes with the coenzyme A binding site of choline acetyltransferase.

The interaction of a series of aromatic dyes with the coenzyme A binding site of choline acetyltransferase was studied. Several of the dyes were very potent inhibitors of the enzyme. With few exceptions, inhibition was competitive with respect to acetylcoenzyme A and noncompetitive with respect to choline. It appears likely that inhibition by dyes such as Reactive Blue 2 (Cibacron Blue F3GA) or Congo Red, as in the case of coenzyme A interactions, involves hydrophobic bonding, as well as a coulombic interaction with an arginine residue.

Animals↗

PubMed1980