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Biomedical subjects

H Gray

Publications and source records attributed to H Gray.

At least 37 records · Page 2Linked to original sources
PubMed1997

Regional variation in the incidence of hip fracture in New Zealand.

AIM: To determine the regional incidence of hip fracture among individuals aged 60 years or older in New Zealand. METHODS: New Zealand Health Information Service inpatient morbidity data for the years 1988-92 were examined by area health board region to identify all hip fractures (ICD N820) among individuals aged 60 years or older. RESULTS: Substantial regional variation exists in the incidence of hip fractures among older people in New Zealand. Among both men and women, similar regional variations were observed with the age-standardised rates being consistently highest in the West Coast (790 per 100,000 for women and 360 per 100,000 in men) and lowest in Northland (540 per 100,000 in women and 185 per 100,000 in men). CONCLUSION: These findings have implications for resource allocation, both in terms of targeting prevention initiatives and in providing acute and long term management of hip fracture patients. In addition, they raise questions as to why such variations in hip fracture incidence exist in New Zealand.

Aged↗
PubMed1996

Characteristics of HIV-infected pregnant women in the Bahamas.

The Commonwealth of the Bahamas has one of the highest rates of acquired immunodeficiency syndrome (AIDS) in the English-speaking Caribbean. A seroprevalence study of pregnant women attending antenatal clinics in New Providence in 1990-91 showed that of 3,914 pregnant women tested, 2.9% were human immunodeficiency virus (HIV) infected. Women born in the Bahamas constituted 79.2% of the women tested; 17.7% were born in Haiti. The rate of HIV infection was 2.5% in the Bahamian women as compared with 4.5% in those born in Haiti. The highest incidence was in women aged 25-34 years and in women who had multiple pregnancies. There was a significant association with a history of crack cocaine use by the Bahamian women. There was also a significant association between a lack of education and HIV infection in this group. There was a lower rate of condom use among women with less education and also among women in common-law relationships, but the association of lack of condom use and HIV infection did not reach statistical significance.

Adolescent↗
PubMed1995

Hip fracture incidence among older people in Auckland: a population-based study.

AIM: To determine the incidence of hip fractures among those aged 60 years or older in the Auckland region. METHODS: Demographic data were obtained on all older people hospitalised with a fracture of the femoral neck in Auckland, between 8 July 1991 and 7 February 1994. Incidence rates were calculated using the 1991 census data. RESULTS: An average incidence of 733 hip fractures or 710 individuals sustaining hip fractures each year was observed. Age-adjusted incidence rates were 571.5 per 100,000 for women and 318.2 per 100,000 for men. 97.0% of the hip fractures were sustained by those identified in the records as European, with the rates for Maori and Pacific Island populations 25-50% lower than for Europeans. Among Maori and Pacific Island populations, incidence rates were similar for men and women. Overall, 41.8% of the hip fractures were sustained by those > or = 85 years, with 67.0% sustained by those > or = 80 years. Incidence rates increased with age, with the rates continuing to increase in those > or = 85 years. CONCLUSION: Among Europeans, hip fracture incidence rates in Auckland are similar to those found for other caucasian populations. However, the rates among Maori and Pacific Island populations are among the lowest internationally and are similar for men and women. The increase in incidence rates with age continues in those > or = 85 years.

Aged↗
PubMed1995

Toward improved glycemic control in diabetes. What's on the horizon?

It has now been firmly established that maintenance of good glycemic control can prevent or retard the development of the microvascular complications of type I (insulin-dependent) diabetes. Although not yet definitively established, it is likely that optimal control of plasma glucose will also assist in the prevention of such problems in type II (non-insulin-dependent) diabetes. While a limited range of therapeutic agents for the treatment of hyperglycemia is currently available, a number of newer therapies are currently undergoing evaluation. In this review, we provide an overview of such treatments and assess their likely place in the therapeutic armamentarium over the next few years.

Diabetes Complications↗
PubMed1995

High prevalence of hepatitis C infection in Afro-Caribbean patients with type 2 diabetes and abnormal liver function tests.

Moderate elevations of serum transaminases are frequently found in patients with diabetes mellitus and are often attributed to fatty infiltration of the liver without further investigation. Recent studies of patients with end-stage liver disease have suggested a possible association between Hepatitis C virus (HCV) antibody positivity and the development of diabetes (mostly Type 2). As a first step in the examination of any potential association between HCV and Type 2 diabetes in subjects without overt liver disease, we examined 200 British patients with Type 2 diabetes (100 White Caucasians, 50 Asians, and 50 Afro-Caribbeans), recruited from the United Kingdom Prospective Study of Diabetes, half of whom had a significant elevation of alanine aminotransferase (ALT) on at least two occasions and half of whom had consistently normal ALT levels. In Afro-Caribbean Type 2 diabetic subjects 7/25 (28%) patients with abnormal ALT and 1/25 (4%) with normal ALT were HCV antibody positive. Among White Caucasian subjects 6/50 (12%) patients with abnormal LFTs and 0/50 with normal LFTs were HCV antibody positive and in Asians the prevalence was 2/25 (8%) and 0/25, respectively. This study suggests that persistent mild to moderate elevation of serum transaminases in a patient with Type 2 diabetes should not automatically be attributed to the metabolic disturbances of diabetes. Particularly in Afro-Caribbean subjects, HCV infection is a major diagnostic consideration. The question of whether HCV infection itself may have a diabetogenic action is worthy of further investigation.

Adult↗
PubMed1994

Insulin resistance as the major cause of impaired glucose tolerance: a self-fulfilling prophesy?

Non-insulin-dependent diabetes (NIDDM) is a heterogeneous state involving various degrees of beta-cell dysfunction and insulin resistance, although the relative importance of these two factors is controversial. Several single gene disorders of carbohydrate metabolism have their main pathophysiological defect largely restricted to the beta-cell or to insulin-sensitive tissues. We have noted that with insulin resistance the fasting plasma glucose is often normal and severe hyperglycaemia occurs after a glucose load. By contrast, in glucokinase-deficient diabetes, which is characterised by reduced insulin secretion, the reverse is the case. Supportive evidence showing that beta-cell dysfunction and insulin resistance may have different effects on fasting and post-prandial glucose concentrations comes from studies of identical twins of NIDDM patients, hemi-pancreatectomised normal subjects, and insulin-resistant Asian subjects. NIDDM is usually preceded by a period of less severe hyperglycemia, referred to as impaired glucose tolerance (IGT). Studies of the IGT phase usually conclude that insulin resistance is the major abnormality and is thus the primary defect in NIDDM. However, the definition of IGT is based on the 2 h plasma glucose after an oral glucose-tolerance test without consideration of the fasting glucose concentrations (provided these concentrations are non-diabetic). Our observations suggest that this definition of IGT may result in the over-representation of insulin-resistant individuals and the under-representation of subjects with beta-cell dysfunction in any cross sectional study of IGT. The belief that the prediabetic state of IGT is dominated by insulin resistance may be a self-fulfilling prophesy because of the excessive emphasis put on the post-prandial rather than the fasting state.

Blood Glucose↗
PubMed1994

Pharmacological thromboprophylaxis in hip and knee surgery: a survey of New Zealand orthopaedic surgeons.

A survey was conducted of the attitudes and practices of New Zealand orthopaedic surgeons on the use of pharmacological thromboprophylaxis (PT) for patients undergoing major hip or knee surgery. A questionnaire was sent to all 106 consultant surgeons known to perform hip or knee surgery and a response rate of 89% was obtained. The results suggested that while almost all surgeons used PT at some time, only about one-third of elective surgery patients and just a few per cent of patients with neck of femur fracture (NOFF) receive PT. For about three-quarters of surgeons, heparin (usually low molecular weight) was the most frequently used PT. About half of the surgeons began prophylaxis pre-operatively and about half stopped it when the patients were mobile postoperatively. Previous venous thromboembolism was felt by almost all surgeons to be a very important indication for PT; gross obesity, prolonged pre-operative immobility and active malignancy were thought to be very important factors by approximately one-half of the surgeons. The presence of a major bleeding diathesis or active peptic ulcer was cited as a contraindication to PT by more than two-thirds of all surgeons. Fear of bleeding complications and the rarity of thromboembolic complications were cited as reasons for limited use of PT by about one-third of surgeons. The results suggest that most surgeons usually rely on non-pharmacological methods of thromboprophylaxis, particularly for NOFF patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Arthroplasty↗
PubMed1994

Biological activity of the growth factor-induced cytokine N51: structure-function analysis using N51/Interleukin-8 chimeric molecules.

The immediate-early gene N51/KC encodes a protein which following expression in the baculovirus system and purification to apparent homogeneity is able to induce chemotaxis and intracellular Ca2+ flux, to compete for 125I-labeled interleukin-8 (IL-8) binding, and upon iodination, to bind specifically to human neutrophils. The activity of N51/KC can be distinguished from that of IL-8 by a number of criteria. First, at equivalent concentrations, the specific binding of [125I]N51/KC to human neutrophils is about 10 times less than that of [125I]IL-8. Second, the competition studies of [125I]IL-8 with IL-8 define a single class of high-affinity receptors, while the presence of both a high- and a low-affinity class of receptors is defined by N51/KC. Third, although the changes in intracellular Ca2+ of fura-2/AM-preloaded human neutrophils elicited by N51/KC and IL-8 are similar, pretreatment of the cells with N51/KC did not result in a loss of response to a subsequent treatment with IL-8; in contrast, treatment with IL-8 did result in the subsequent desensitization to N51/KC. To further characterize N51/KC, mutants and hybrids of N51/KC and IL-8 were produced and analyzed for the ability to compete for [125I]IL-8 binding and elicit intracellular Ca2+ changes in human neutrophils. Two important observations came from these studies. First, the N51/IL-8I hybrid in which the N51/KC sequence between cysteines 2 and 3 (or first disulfide bond) is replaced by the corresponding sequence in IL-8 shows IL-8-like properties, indicating that this region is important for specific receptor recognition. Second, the N51 delta III and IL-8 delta III C-terminus deletion mutants were biologically inactive, but the hybrid molecules N51/IL-8III and IL-8/N51III, in which the C termini were exchanged, had biological activities similar to that of the wild-type molecules, demonstrating that the presence of the C terminus is essential for the biological activity of these chemokines but does not confer receptor specificity.

Amino Acid Sequence↗
PubMed1992

Purification and identification of subunit structure of the human mitochondrial DNA polymerase.

The mitochondrial DNA polymerase of HeLa cells was purified 18,000-fold to near homogeneity. The purified polymerase cofractionated with two polypeptides that had molecular mass of 140 and 54 kDa. The 140-kDa subunit was specifically radiolabeled in a photoaffinity cross-linking assay and is most likely the catalytic subunit of the mitochondrial DNA polymerase. The purified enzyme exhibited properties that have been attributed to DNA polymerase gamma and shows a preference for replicating primed poly(pyrimidine) DNA templates in the presence of 0.5 mM MgCl2. As in the case of mitochondrial DNA polymerases from other animal cells, human DNA polymerase gamma cofractionated with a 3'----5' exonuclease activity. However, it has not been possible to determine if the two enzymatic activities reside in the same polypeptide. The exonuclease activity preferentially removes mismatched nucleotides from the 3' end of a duplex DNA and is not active toward DNA with matched 3' ends. These properties are consistent with the notion that the exonuclease activity plays a proofreading function in the replication of the organelle genome.

Base Sequence↗
PubMed1991

AIDS legislation.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1989

The effects of dopexamine hydrochloride on cardiopulmonary haemodynamics following cardiopulmonary bypass surgery.

We studied the effects of dopexamine hydrochloride in 14 patients following cardiopulmonary bypass for coronary revascularisation (12 patients) or valve replacement (2 patients). The drug was administered by intravenous infusion at rates of 1, 2, 4 and 6 micrograms/kilogram/minute for a period of 10 minutes at each dose. Measurements of heart rate, blood pressure, right atrial pressure, pulmonary arterial pressure, pulmonary arterial wedge pressure and cardiac output (thermodilution method) were made at the end of each period. There were significant increases in heart rate (P less than 0.05), cardiac index (P less than 0.05) and systolic blood pressure (P less than 0.05). There were significant falls in systemic vascular resistance (P less than 0.05) and pulmonary vascular resistance (P less than 0.05). There were no significant changes in pulmonary arterial or wedge pressure. No serious adverse effects were observed. Dopexamine hydrochloride appears to be a useful supportive agent in patients following cardiopulmonary bypass, although further trials need to be carried out in order to establish precise therapeutic indications for its use.

Adrenergic Agonists↗
PubMed1988

Diagnosis of pulmonary hypertension from radiographic estimates of pulmonary arterial size.

The reported accuracy of radiographic measurements in predicting pulmonary hypertension is very variable. Measurements of right and left descending pulmonary artery diameter have been reported to provide a correct diagnosis in as many as 98% of patients. A study was carried out to determine the predictive value of measurements made from the chest radiographs of 50 normal subjects and of 27 patients undergoing right heart catheterisation for cardiac or pulmonary vascular disease, taking account of radiographic magnification. After such corrections a right descending pulmonary artery diameter over 16.7 mm or a left descending pulmonary artery diameter of over 16.9 mm distinguished 12 of 23 pulmonary hypertensive subjects, with no false positive results. The diameter was then arbitrarily squared (any differences between patients and control subjects being exaggerated) and the product was divided by either predicted or actual lung volume in an attempt to correct for body size. The new index distinguished 19 of 23 patients with pulmonary hypertension, with one false positive, when the divisor was actual lung volume; when predicted lung volume was used 18 of 23 patients were distinguished, again with one false positive result.

Adult↗