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Biomedical subjects

A McKenzie

Publications and source records attributed to A McKenzie.

At least 19 recordsLinked to original sources
PubMed1992

HCMV-DNA is detected more frequently than infectious virus in blood leucocytes of immunocompromised patients: a direct comparison of culture-immunofluorescence and PCR for detection of HCMV in clinical specimens.

In two studies comparing detection of human cytomegalovirus (HCMV) in 118 patients (93 of whom were immunocompromised) by the polymerase chain reaction (PCR) and virus isolation using either early antigen detection by culture-immunofluorescence or conventional cytopathic effect, DNA-PCR was found to be the most sensitive, followed by culture-immunofluorescence, then by cytopathic effect. Urine was inhibitory to the action of Taq polymerase; this was overcome by concentration of HCMV with PEG 6000 prior to gene amplification. Without PEG treatment, HCMV-DNA in 6 of the 11 specimens positive by culture-immunofluorescence was not detectable by PCR. In healthy seropositive individuals, HCMV-DNA was not detected in leucocytes. However, in immunocompromised patients with AIDS or transplants, and therefore at high risk of HCMV infection or reactivation, blood leucocytes were usually positive for HCMV-DNA (19/20), some for as long as 20 weeks after initial detection and persisting for long after culture-immunofluorescence became negative. Neither HCMV-RNA nor infectious HCMV were detected in the follow-up blood leucocyte specimens from immunocompromised patients who had detectable HCMV-DNA in these cells. These data suggest that persistence of HCMV-DNA in blood leucocytes of immunocompromised patients after reactivation or primary infection may be due to persistence of non-viable virus, residual HCMV genomic DNA, or latent HCMV-DNA.

Base Sequence↗
PubMed1992

Pseudotumoral paraesophageal varices.

We report a case of paraesophageal varices presenting as a posterior mediastinal mass in a patient with long-standing portal hypertension. These collaterals were present, despite multiple previous sclerotherapies for submucosal esophageal varices and no endoscopic evidence of their recurrence.

Adult↗
PubMed1992

Haemodynamic changes and physical performance at comparative levels of haemoglobin after long-term treatment with recombinant erythropoietin.

Physical performance and haemodynamic parameters at rest and with exercise were compared in a prospective, cross-over fashion in 12 anaemic haemodialysis patients (Hb 6.4 +/- 0.5, mean +/- SEM) at two levels of haemoglobin (Hb 9 and 12 g/dl) before and after long-term treatment with recombinant human erythropoietin (rHuEpo). Patients were divided into two groups and measurements made prior to treatment, upon reaching, and after 4 months at the first target Hb (9 g/dl group A, 12 g/dl group B), and after 4 months at the alternative target Hb. Tests included an exercise radionuclide ventriculogram, Doppler echocardiogram, and respiratory function exercise test. Compared to pretreatment, there was a significant reduction in resting pulse rate (P < 0.001), and in pulse rate (P < 0.001) and arterial lactate (P < 0.01) concentrations at specified levels of exercise. Work capacity improved 60% (P < 0.001), and left ventricular mass fell by 26% (P < 0.001). Although cardiac output (CO) during and after exercise was reduced (P < 0.05), resting CO, cardiac index, stroke volume and ejection fraction (rest and exercise) were not significantly altered. There appeared little benefit in having the higher target Hb: no significant difference could be found between target levels for almost any measure. In addition, despite marked improvement from pretreatment levels, performance parameters were still below those of non-uraemic age-matched controls. These results demonstrate the beneficial but incomplete effect of rHuEpo on resting and exercise-related factors, and suggest that most improvement is achieved with modest increments in haemoglobin.

Anemia↗
PubMed1992

Endoglin: a 180-kD endothelial cell and macrophage restricted differentiation molecule.

A MoAb RMAC8 was generated by immunizing Balb/c mice with cultured human umbilical vein endothelial cells (HUVE). The molecule recognized had a mol. wt of 180 kD non-reduced, 95 kD after reduction and 66 kD in its reduced and N-deglycosylated form. Sequential immunoprecipitation studies with the MoAb 44G4, which recognizes the O- and N-glycosylated homodimer endoglin, showed that both MoAbs recognize the same molecule on HUVE and phorbol myristate acetate (PMA)-stimulated U937 cells. The distribution of the RMAC8-recognized molecule was the same as that described for endoglin, i.e. arterial and venous endothelium, myelomonocytic and pre-B leukaemia cells and cell lines; however, unlike 44G4, RMAC8 also reacted weakly with monocytes and strongly with in vitro differentiated macrophages as well as peritoneal and alveolar macrophages. This distribution of endoglin was confirmed by Northern blot analysis using a full length endoglin cDNA probe. These studies suggest that endoglin is a differentiation marker on macrophages.

Antibodies, Monoclonal↗
PubMed1992

A case of hepatic hydrothorax due to a large diaphragmatic defect.

Hepatic hydrothorax is an infrequent complication of cirrhosis. The source of pleural fluid has been the subject of considerable speculation. A case of hepatic hydrothorax is discussed which illustrates a large diaphragmatic defect as the cause of ascitic fluid passing into the pleural cavity.

Adult↗
PubMed1992

Identifying hazards and risk opportunity in child farm injury.

Although children are overrepresented in farm injury, little is known about the environmental hazards and risk behaviours associated with injury, or about how to identify these factors at a local level. This study addresses the measurement of these hazards and hazardous behaviours. The study was conducted in 1990 at Gloucester, New South Wales, a small dairy, beef and hobby farm community. After some formative research and local consultation, a checklist survey was constructed and sent to 120 farm families with school-age children. Families were sent the checklist forms again two weeks later to assess test-retest reliability, which was found to be acceptable among the 38 per cent who responded on both occasions. The findings on the prevalence of environmental hazards and risk behaviours from the 84 per cent of respondents were useful to refine the existing injury information available from local hospital morbidity figures, which had identified injuries related to riding (horses, bicycles and motorcycles) and to machinery and drowning as major rural injury issues. In particular the importance of bicycle riding and horse-related injury were confirmed. The survey importantly identified some previously undetected issues, most notably the danger to children's hearing. The prevalence data were used to identify targets for the development of local health promotion initiatives, leading the local farm safety action group to select horses, helmets and hearing as issues for preventive action. Findings from the method indicated the importance of local information, involving farmers in constructing the checklist, and feeding back results to the community.

Agriculture↗
PubMed1992

An evaluation of late attenders in labour in Alexandra.

To study why women present in late labour we interviewed 70 parturients in our labour room for a period of 8 days in March 1990. When presenting 19% were 8-10 cm dilated and 81% were 0-7 cm dilated. The group was stratified into those in early labour (0-7 cm of cervical dilatation) and in late labour (8 cm or more) and compared for all variables studied. Only a few differences were statistically significant. Early comers were less likely to have strong uterine contractions and more likely to have intact membranes at presentation. Late comers were more likely to report a number of delaying factors or to have financial worries. Twenty nine percent of Alexandra residents and only 6% of outsiders reported difficulty in finding transport to labour room after the onset of labour. Almost half of Alexandra residents did not have access to public transport, ambulance or own transport. The relative risk for late coming was: 9 for women reporting a number of delaying factors outside their control; 6 for those with financial worries or with ruptured membranes; 4 for unbooked cases or with current addresses in Alexandra; 3 for women with a normal past obstetric history or with a previous delivery outside the AHC; 2 for those worried with hospital referrals, with a previous rural address, for less than 1 year in Alexandra or with a normal current ANC. Women who came late in labour were more likely to need hospital referral or to have come to the labour unit walking.

Adult↗
PubMed1991

Evaluation of blood pressure screening at the Alexandra Health Centre.

A review of patient registers and records at the Alexandra Health Centre and University Clinic (AHC) revealed that less than 10% of the expected number of hypertensive subjects in Alexandra are attending the twice a week hypertension clinic. In the adult outpatient department most patients are not screened for hypertension. Patients are more likely to be screened if they have symptoms suggestive of high blood pressure and are seen in the morning by a primary health care nurse. Age and sex of patients are not important determinants of hypertension screening. It is thus apparent that primary care consultations at the AHC are not used as opportunities for screening for a serious and common illness for which there is ready treatment. However, before the AHC embarks on a massive case-finding programme there is a need to develop efficient and affordable treatment programmes.

Adolescent↗
PubMed1991

Toxicity from ragwort and fat cow syndrome, or from industrial chemicals: the value of epidemiological analysis for interpreting clinico-pathological findings.

When livestock in close proximity to industries develop signs of ill-defined disease, toxic effects from industrial pollution should be considered in the differential diagnosis. In establishing the final diagnosis, epidemiological methods should be applied to supplement the clinical and pathological techniques. This viewpoint is illustrated by two case-histories describing episodes of cattle disease in central Scotland. A long-established and successful dairy herd in central Scotland sustained severe morbidity and mortality amongst animals which had grazed on a field beside a recently established dump which contained wastes from a chemical waste incinerator. An official investigation concluded that the episode of disease was the result of ragwort poisoning; this diagnosis was reached on clinical and pathological grounds only. A similarly unexpected and severe epidemic occurred a few years later in another dairy herd, about 1 km further away from that incinerator (which was also within 100 m of a municipal incinerator). The official investigation, which again focused on clinical and pathological criteria, led to the diagnosis of fat cow syndrome. In the first episode, contaminated water drained from the chemical waste dump on to the cows' field; in the second episode, the relevant field was affected by airborne pollution from the two waste incinerators mentioned earlier. In both episodes, the epidemiological features, which were not examined systematically by the original investigators, were consistent with the hypothesis that these episodes resulted from exposures to toxic contaminants.

Animals↗
PubMed1991

Computed tomographic and ultrasound appearances of focal spared areas in fatty infiltration of the liver.

Computed tomography (CT) and ultrasound (US) appearances of diffuse and focal fatty infiltration of the liver (FIL) are well recognized. We have recently seen 10 cases with "fat spared" areas in FIL presenting as pseudo tumours of the liver. Characteristic appearances of fat free areas in FIL which help differentiate these areas from other focal liver lesions include (i) location in the medial segment of the left lobe of the liver, (ii) absence of mass effect on surrounding vessels and liver tissue, and (iii) presence of typical changes of FIL elsewhere in the liver on CT or US examination.

Fatty Liver↗
PubMed1991

Heterogeneity in oxygen diffusion around venous ulcers.

The pathogenesis of venous ulceration is thought to involve the formation of fibrin cuffs around dermal capillaries. Consistent with a barrier effect of fibrin, it has been shown that the dermal diffusion of oxygen, as measured by transcutaneous oxygen pressure (TcPO2), is decreased in limbs affected by venous ulcer. However, it is unknown whether oxygen diffusion around the perimeter of venous ulcers is uniformly affected. In this study, we investigated TcPO2 values at four different quadrants around the ulcers of 14 patients, the contralateral leg of five patients with unilateral ulcers, and the leg of six normal individuals. These values were also compared to TcPO2 measurements at the chest. Our results indicate that, whereas TcPO2 values in limbs affected by venous ulcers are much lower than normal, there is a great deal of variability in oxygen diffusion around individual ulcers. These findings may represent a heterogeneity in the disease process affecting the leg.

Adult↗
PubMed1991

Pneumomediastinum after a transbronchial biopsy.

A pneumomediastinum occurred after a transbronchial biopsy in a woman with pulmonary fibrosis and was confirmed by computed tomography. Although pneumomediastinum has a pathogenesis similar to that of pneumothorax it has not been reported after transbronchial biopsy.

Biopsy↗
PubMed1991

Organisation of veterinary public health in Australasia and the Pacific Islands.

The authors present the structure and functions of the Veterinary Public Health Services in Australasia and the Pacific Islands. Services in the region range from the extensive and highly developed organisations of Australia and New Zealand to those meeting the needs of the subsistence agriculture economies of some of the smaller island groups. Geographic isolation and strict quarantine measures have kept the region free from serious infectious animal diseases, and veterinary public health efforts are concentrated on preventing and combating epizootic diseases.

Animals↗