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Biomedical subjects

W Young

Publications and source records attributed to W Young.

180 records · Page 10Linked to original sources
PubMedDate not supplied

Recent Chinese migrants' health, adjustment to life in New Zealand and primary health care utilization.

A community survey of 271 Chinese migrants aged 15 years and older living in Auckland was conducted to assess self-rated adjustment and health. The majority of respondents came from Hong Kong and Taiwan. Despite significant changes in their lives, including the absence of family members, unemployment and underemployment, most did not report major adjustment problems or regret having come to New Zealand. Few considered their health to be poor. Forty-two per cent reported having consulted a doctor within the past 12 weeks. Factors significantly associated with having experienced major problems included being aged 26-35 years, rejection from locals and having low English proficiency. Factors associated with poor adjustment included expectations not having been met, regretting coming, low proficiency in English, recent arrival in New Zealand, unemployment, younger age and lower levels of education. Self-rated fair or poor health was found to be associated with Chinese-only reading knowledge, residency of more than 5 years and regretting having come to New Zealand.

Acculturation↗
PubMedDate not supplied

H2 clearance measurement of blood flow: a review of technique and polarographic principles.

H2 clearance is a powerful method for monitoring blood flow. Simple and inexpensive to implement, the method allows multiple in situ determinations of blood flow from any tissue in which a small electrode can be implanted. There is, however, evidence to suggest that H2 clearance is neither as accurate nor as local a measure of blood flow as generally supposed. Both in theory and practice, it probably cannot accurately determine blood flow rates greater than 100 ml/100 gm/min or localize blood flow to tissue volumes of less than 5 ml. Moreover, its experimental application is complicated by many technical problems hitherto largely ignored by workers in the field. Some of these problems arise from the limitations of the steady state polarographic technique used to measure tissue H2 concentrations. Other problems stem from the failure to consider possible sources of error in H2 clearance monitoring; these induce interference with the H2 signal by spurious electrode and tissue currents, and contributions from tissue ascorbate and O2. Nevertheless, with the appropriate safeguards and qualifications, H2 clearance is a valid and important approach to measuring blood

Animals↗
PubMedDate not supplied

Regional brain sodium, potassium, and water changes in the rat middle cerebral artery occlusion model of ischemia.

Middle cerebral artery occlusions (MCAo) in rats produce infarcts in the pyriform and frontoparietal cortex, extending into the lateral basal ganglia and parasagittal cortex. We estimated tissue H2O concentrations from wet and dry weight measurements and determined Na and K concentrations by atomic absorption spectroscopy in these areas of rat brains. Tissue samples were analyzed at 2, 4, and 24 hours after MCAo and sham MCAo, compared with normal values measured in unoperated rats. In the pyriform and frontoparietal areas, H2O concentrations increased to 34 and 7% greater than normal by 2 hours, and 89 and 94% by 24 hours after MCAo. Na concentrations rose in these areas to 73 and 37% greater than normal by 2 hours, and 281 and 330% by 24 hours. K concentrations did not change until 4 hours, but fell to 62 and 34% of normal in these areas by 24 hours. Such large ion shifts indicate severe tissue destruction. In the parasagittal cortex and basal ganglia areas, the ion and water changes were smaller and did not become significant until 24 hours after MCAo. Rates of Na entry into the infarct site were greatest at 0-2 hours, while the rates of K loss peaked later, between 2 and 4 hours. The difference in Na influx and K efflux resulted in net ion shifts that correlated highly with water entry, yielding a correlation coefficient of 0.992 (p less than 0.001) and a slope indicating that 1 ml of water entered the tissue with each 145 mumoles of ions. These findings strongly suggest that net ion shifts cause the early edema of regional brain ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Regional brain calcium changes in the rat middle cerebral artery occlusion model of ischemia.

Entry of Ca ions into ischemic neurons is believed to cause cell damage. Although several investigators have demonstrated changes in extracellular Ca ionic activity consistent with Ca movement into cells, direct and quantitative evidence for Ca entry into ischemic cells is lacking. We used atomic absorption spectroscopy to measure the regional distribution of tissue Ca contents of rat brains sampled at 2, 4, and 24 hours after middle cerebral artery occlusion (MCAo). At 4 hours after MCAo, Ca concentrations increased significantly (p less than 0.005) in the ischemic middle cerebral artery territory, i.e., the pyriform and frontoparietal cortices, but not in the surrounding brain. At 24 hours, Ca concentrations in the pyriform and frontoparietal cortex were respectively 30.79 (+/- 2.90) and 29.19 (+/- 3.28) mumol/g dry tissue wt compared with 11.9 (+/- 1.7) mumol/g in sham-occluded rats. Tissue Ca concentration changes in the parasagittal cortex and basal ganglia adjacent to the infarct site were much smaller and did not differ significantly from controls until 24 hours. In the ischemic middle cerebral artery territory, greater than 1.0 mumoles of Ca entered per gram of dry tissue weight per hour during the first 4 hours after MCAo. Linear regression analysis revealed a significant correlation (r = 0.9722) between changes in tissue Ca and water, with a slope indicating that 5.88 mumoles of Ca accompanied each milliliter of water entering the lesioned hemisphere. Such massive accumulations of Ca not only confirm Ca entry into injured cells, but indicate the presence of a remarkable Ca sink which sequestered within 24 hours more than 17 times the amount of free Ca present in the tissue before MCAo.

Animals↗
PubMedDate not supplied

Posttraumatic syrinx formation: experimental study.

An experimental study was performed to examine posttraumatic spinal cord cavitation in an animal model by evaluating immediate and delayed computed tomographic (CT) scans obtained after administration of intrathecal contrast material. Four cats underwent midthoracic laminectomy and spinal cord contusion using a standard 400 g-cm model. All animals were studied by CT with intrathecal contrast enhancement before and 4-5 days, 3-4 weeks, and 7-13 weeks after experimental cord contusion. Either metrizamide or iopamidol was used as the contrast agent. Two of the four cats had CT and pathologic evidence of cord cavitation at the site of injury. Another animal had uptake of contrast material into the spinal cord without pathologic evidence of cyst formation, which was believed to represent malacic change. The fourth animal had a normal-appearing cord by both CT and pathologic criteria. Animals that received metrizamide after cord contusion had generalized myoclonic seizures. This did not occur when iopamidol was administered.

Animals↗
PubMedDate not supplied

Hospitalization rates of children with gastroenteritis in Ontario.

PURPOSE: To calculate hospitalization rates of gastroenteritis among children in Ontario and to determine the association of hospitalization of gastroenteritis with sociodemographic indicators and the availability of hospital beds. METHODS: Ontario admission rates were calculated from hospital discharge data for fiscal year 1991/92. Small area variations, correlations between sociodemographic indicators and admission rates were studied. RESULTS: The age- and sex-adjusted admission rate in 1991/92 was 411.1/100,000 with a 14-fold variation in Ontario. The availability of paediatric beds was the only significant factor associated with high admission rates, with an estimated relative risk of 6.75 (95% confidence interval: 1.26, 36.09, p < 0.027). CONCLUSION: Since most children with gastroenteritis can be successfully managed as outpatients, high admission rates may be an indication of unnecessary hospitalization.

Adolescent↗
PubMedDate not supplied

Conservative treatment of intra-abdominal abscess in children.

Fifty-three children under 18 years of age with sonogram-proved intra-abdominal abscess (IAA) were seen between July 1993 and June 1996 at the Department of Pediatrics of the Mackay Memorial Hospital, then were studied retrospectively. Following a course of conservative treatment and follow-up with serial sonographic studies, 42 (79.3%) patients responded favourably to antibiotics treatment without drainage procedure. The other 11 patients' condition deteriorated, and surgical intervention was performed. The gradual shrinkage and completely resolved periods of the abscesses averaged 27.9 days. The average duration of antibiotic treatment was 23.6 days, intravenously for average 12.2 days followed by oral treatment until the abscess was completely resolved (average 11.4 days). The intra-abdominal abscess recurred in 3 (5.7%) patients. The experience demonstrates that pediatric patients with an intra-abdominal abscess must be followed closely by sonography, and they can be managed successfully with appropriate antibiotics alone. Surgical intervention is still needed if symptoms and signs persist or deteriorate.

Abdominal Abscess↗