Biomedical subjects

P Sexton

Publications and source records attributed to P Sexton.

4 recordsLinked to original sources

PubMed1998

Impact of age on modulation of norepinephrine release from sympathetic nerves in the rat superior mesentery artery.

There is an age-related increase in stimulation-evoked fractional norepinephrine release in tail arteries of Fischer 344 rats from 6-20 months of age. Previous studies have ruled out changes in the function of uptake and subsequent metabolism mechanisms, or feedback by prejunctional alpha2-adrenoceptors. The tail artery is important in thermoregulation, and there is the possibility that the previously observed increase in sympathetic nerve activity is due to age-related changes in thermoregulation as opposed to a fundamental age-related change in the regulation of sympathetic nerves. Thus, we measured stimulation-evoked norepinephrine release in another blood vessel model, the superior mesentery artery using HPLC with electrochemical detection. In this study fractional norepinephrine release was measured under three separate conditions, drug free Krebs'; in the presence of deoxycorticosterone and cocaine; in the presence of deoxycorticosterone and cocaine and the alpha2-adrenergic receptor antagonist, idazoxan. The most significant finding was that fractional norepinephrine release in mesentery arteries from 20-month-old animals was higher as compared to 6 months regardless of treatment condition. Furthermore, the elevation in norepinephrine release cannot be accounted for by changes in norepinephrine content, uptake and subsequent metabolism mechanisms or changes in basal norepinephrine release. These data from the mesentery artery model confirm and support our previous work in the rat tail artery model. In addition, the data from this study suggest the possibility that there are common mechanisms underlying the age-related increase in peripheral sympathetic nerve activity.

Adrenergic Fibers↗

PubMed1995

Regional differences in cardiovascular risk factor prevalence in Tasmania: are they consistent with the increased cardiovascular mortality?

BACKGROUND: The death rate from cardiovascular disease in Tasmania has been among the highest in Australian States for a number of years. The North-West (NW) and Northern regions of Tasmania account for most of the increased mortality. AIMS: To determine the prevalence of cardiovascular risk factors in the North and NW regions of Tasmania and to ascertain whether any differences are consistent with the regional patterns of mortality for ischaemic heart disease (IHD) within the State. METHODS: The design of the study was almost identical to the previous National Heart Foundation (NHF) Risk Factor Prevalence Survey conducted in 1989. The subjects, aged 20-69 years, were randomly selected from the Electoral Roll with 1146 subjects participating in the North and 1219 in the NW. Subjects answered a detailed questionnaire and then underwent a brief physical examination with venipuncture for blood lipids. Hobart data from the NHF Risk Factor Prevalence Survey in 1989 were used as an estimate of risk factor prevalence in the Southern region. RESULTS: In both males and females, mean systolic blood pressure was significantly higher in the NW than the South which was in turn higher than the North. Mean serum cholesterol levels in males were higher in the NW than the North. Smoking behaviour was similar in males and females in all regions. Males and females in the NW and North were more inactive than those in the South. Similar proportions in all regions were on either 'no specific' or 'fat modified' diets. Body mass index in males and females was higher in the NW and North but waist to hip ratios failed to show a consistent trend. CONCLUSIONS: While the NW has an unfavourable risk factor profile compared with the South, the North does not. The risk factor data are broadly consistent with, but unlikely to be sufficient to explain fully, the regional differences in mortality from IHD.

Adult↗

PubMed1989

Chronic strongyloidiasis in Tasmanian veterans--clinical diagnosis by the use of a screening index.

Chronic infection with Strongyloides stercoralis presents a diagnostic problem because of the low recovery of the organism from stools and the insensitivity of current serological tests. Of 150 former Far East POWs, 26 (17%) had S. stercoralis in stools. The clinical features in 18 stool-positive patients were compared to those in 24 stool-negative patients and showed that strongyloidiasis was associated with a higher frequency of alteration in bowel habit, upper abdominal discomfort, rash and eosinophilia. On the basis of these features, a screening index was devised which largely separated stool-positive and stool-negative patients and led to helpful therapy in three of four patients with compatible symptoms who lacked a definitive diagnosis. Treatment with thiabendazole appeared to be superior to treatment with mebendazole.

Abdominal Pain↗

PubMedDate not supplied

Development and implementation of a skin care program.

The incidence of nosocomial pressure ulcers for the identified high-risk patient care areas totaled 21% of the 152 patients in the first skin audit. The incidence of nosocomial pressure ulcers for the second audit of 156 patients was 12%. The second skin audit was accomplished six months after the implementation of a skin care program that included assessment forms, general and unit based education of nursing staff, development and implementation of Standards of Care for Skin Care, and provision of skin care products on the nursing unit. The population characteristics of the total sample indicated a fairly even male-to-female ratio and the average age was 60 to 69 years for both audit populations. The mode for the first audit was age 70 to 79 and for the second was 60 to 69. Most of the sample experienced neurological and musculoskeletal problems that adversely affected the patients mobility. One-fourth of the first sample and 1/2 of the second audit sample were bedridden. One-fifth of both samples experienced incontinence and almost 1/3 of both samples used incontinence devices (Foleys and collectors).

Academic Medical Centers↗