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Biomedical subjects

M McKenzie

Publications and source records attributed to M McKenzie.

8 recordsLinked to original sources
PubMed1992

Subunit interactions of vesicular stomatitis virus envelope glycoprotein stabilized by binding to viral matrix protein.

The mechanism by which viral glycoproteins are incorporated into virus envelopes during budding from host membranes is a major question of virus assembly. Evidence is presented here that the envelope glycoprotein (G protein) of vesicular stomatitis virus binds to the viral matrix protein (M protein) in vitro with the specificity, reversibility, and affinity necessary to account for virus assembly in vivo. The assay for the interaction is based on the ability of M protein to stabilize the interaction of G protein subunits, which exist as trimers of identical subunits in the virus envelope. The interaction with M protein was shown by using G proteins labeled with fluorescent probes capable of detecting subunit dissociation and reassociation in vitro. The results show that the M protein isolated from virions either as purified soluble protein or as nucleocapsid-M protein complexes interacts with the G protein in vitro and that the reaction is reversible. The interaction between the G and M proteins was not serotype specific, but no interaction between the vesicular stomatitis virus M protein and the influenza virus hemagglutinin could be detected. These results support the conclusion that the interactions described here are the ones that govern assembly of G protein into virus envelopes in vivo.

Fluorescence↗
PubMed1992

Vaccination of Lewis rats against Mycoplasma arthritidis-induced arthritis.

The nature of Mycoplasma arthritidis antigens responsible for eliciting protective immunity in rats was studied by inoculation of rats with mycoplasmal components that had been subjected to a variety of physical and chemical treatments. All inocula tested induced good protection against development of clinical illness, as assessed by changes in body weight and appearance of joint swelling and/or temporary hind limb paralysis. Although all preparations stimulated development in inoculated rats of high titer of antimycoplasmal antibodies measured by ELISA, the complement-fixation antibody response was poor and, in some cases, lacking altogether. This indicated that completion-fixation antibodies may not be involved in protecting rats against M arthritidis-induced illness. Protective antigens were stable to heat (100 C for 10 minutes), formalin, and denaturation by sodium dodecyl sulfate (SDS). Inoculation with membrane and soluble cytoplasmic fractions was protective, as was inoculation with 5 M arthritidis fractions separated according to molecular weight by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). For this latter experiment, rat antisera obtained after vaccination, but prior to challenge exposure, were tested by immunoblot analysis against electrophoretically separated M arthritidis membrane proteins. Interestingly, all antisera from these rats recognized antigens migrating far outside the molecular weight range of the cell fractions with which rats were inoculated. This indicated either that the protective antigens may be composed of numerous antigenically related subunits that separated by SDS-PAGE into a variety of molecular weight ranges or that a few major antigens may exist in several forms or phases within a given population of M arthritidis.

Animals↗
PubMed1991

Wound infections in orthopedic surgery: effect of extended surveillance on infection rate.

Substantial evidence now exists that ongoing surveillance of surgical wound infections can contribute to reduced infection rates. What is not yet determined is whether surveillance should be limited to the postoperative hospital stay or should be continued after patient discharge. To determine the number of infections occurring after discharge, the authors contacted a random sample of their patients who did not have wound infections during their hospitalization after orthopedic surgery. This was done 30 days after the procedure. The authors selected 273 patients of 1375 who underwent orthopedic surgery over a 7-month period and were able to contact 199 (73%). At the 30-day follow-up 23 patients (11.6%) had wound infections, as judged by wound discharge and physician prescription of antibiotics in 20 and the patient's description of pus issuing from the wound in 3. During the same period postoperative wound infections were found in only 19 (1.5%) of 1278 patients who were subjected to in-hospital surveillance. The authors conclude that, in patients who undergo orthopedic procedures, the majority of wound infections occur after discharge from the hospital and that infection rates based only on in-hospital surveillance greatly under represent true surgical wound infection rates for orthopedic procedures.

Alberta↗
PubMed1979

Multiple primary prostate cancer.

Although increasing reports are noted of apparent endometrial carcinoma of prostatic origin, the controversy is present of the actual existence of such an entity. The association of papillary prostatic cancer (endometrial or ductal) with the typical microacinar variety has also been previously presented. This report is an account of 2 cases of multiple prostatic primary tumors. The first case is the twelfth reported case of endometrial (utricular) carcinoma not only simultaneously associated with microacinar type carcinoma, but also with a previous transitional carcinoma of the urinary bladder. The second case is a papillary carcinoma and associated microacinar type with the papillary component responding dramatically to chemotherapy. Significant aspects of interest in this case include the site of papillary metastasis to the lungs, elevated estrogen levels with normalization after treatment, and finally response to chemotherapy.

Adenocarcinoma, Papillary↗
PubMed1978

A human plasma component that binds benzo(a)pyrene.

A component capable of binding benzo(a)pyrene was measured in plasma from cigarette smokers and nonsmokers. This plasma fraction was found to have a high specificity of binding to benzo(a)pyrene, bound benzanthracene competitively with benzo(a)pyrene, and was positively correlated (r = 0.861, p less than 0.001) with the capacity of the individual subject's lymphocytes to be induced for AHH activity in culture. An inverse correlation (r = -0.957, p less than 0.001) between the presence of the plasma component in lung cancer patients and the capacity of lung cancer patients' lymphocytes to be induced in culture is unexplained at this time. A benzo(a)pyrene-binding fraction was not found in induced or uninduced cultured lymphocytes from smokers or nonsmokers, or in homogenates of lung excisional tissue from smokers with or without primary lung cancer.

Aryl Hydrocarbon Hydroxylases↗
PubMed1978

Steroid hydroxylase induction in cultured human lymphocytes: effects of the menstrual cycle.

Steroid hydroxylases (SAH) are inducible in cultured human lymphocytes following treatment with estradiol-17beta. The enzyme systems induced are carbon monoxide sensitive and convert estradiol-17beta to a metabolite chromatographically indistinguishable from estriol. The level of inducibility of SAH varies drastically over a normal menstrual cycle with maximum induction in the late follicular phase and minimum induction during the luteal phase. The use of an oral contraceptive containing both a synthetic progestogen and ethynyl estradiol reduced SAH induction levels to those typically seen during the luteal phase of the menstrual cycle.

Cells, Cultured↗