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Biomedical subjects

M Grigg

Publications and source records attributed to M Grigg.

17 recordsLinked to original sources
PubMed2001

Alpha1A- and alpha1B-adrenoceptors are the major subtypes in human saphenous vein.

In this study we analyzed the different alpha1-adrenoceptor (AR) subtypes present in human saphenous vein (HSV) using reverse transcription polymerase chain reaction (RT-PCR), DNA-DNA hybridization analysis and functional affinities for alpha-AR antagonists. DNA-DNA hybridization analysis of RT-PCR amplification products confirmed the presence of alpha1A- and alpha1B-ARs, and low levels of alpha1D-AR in HSV. The functional results showed: (1) prazosin, the selective alpha1-AR antagonist, phentolamine, the alpha1- and alpha2-ARs antagonist, WB 4101 and 5-MU, the selective alpha1A-AR subtype antagonists were potent, competitive antagonists of noradrenaline (NA)-induced contraction (pA2 values of 11.03, 8.06, 9.02 and 8.34, respectively). (2) Alpha1-AR-induced contraction was sensitive to the alkylating effects of CEC (the alpha1B and alpha1D-AR subtypes antagonist) and (3) The selective alpha1D-AR subtype antagonist BMY displayed low affinity (pA2 values of 6.44). This indicates that the contractile response of the HSV to alpha1-AR-induced is predominantly mediated by both alpha1A and alpha1B-AR subtypes. This was also supported by the good relationship between pA2 values from the present study and reported binding affinities (pKi) values of various alpha1-AR subtype antagonists with cloned human alpha1A- and alpha1B-AR subtypes (r=0.89 and r=0.98, respectively), but not the alpha1D-AR subtype (r=0.67). Our results indicate that alpha1A- and alpha1B-ARs are the main functional and expressed receptor subtypes in HSV.

Adrenergic alpha-Antagonists↗
PubMed2001

Evaluating complex, collaborative programmes: the Partnership Project as a case study.

OBJECTIVE: In Australia, mental health services are delivered by a complex web of public- and private-sector providers. There is a growing recognition that linkages between these groups are not optimal, and a concern that this may lead to poor outcomes. This paper illustrates a conceptual framework for developing, implementing and evaluating programmes concerned with linkages. METHOD: Drawing on theoretical and practical literature, this paper identifies different levels of integration, issues in evaluating programmes to address poor linkages, and features of useful evaluations. Within this context, it describes the method by which the Public and Private Partnerships in Mental Health Project (Partnership Project) is being evaluated. Conducted by St Vincent's Mental Health Service and The Melbourne Clinic, this is one of several Demonstration Projects in Integrated Mental Health Care funded under the National Mental Health Strategy. RESULTS: Collaboration is hard to conceptualize and collaborative programmes usually have many players and components, and tend to operate within already-complex systems. This creates difficulties for evaluation, in terms of what to measure, how to measure it, and how to interpret findings. In spite of these difficulties, the illustrative example demonstrates a model for evaluating collaborative programmes that is currently working well because it is strongly conceptualized, descriptive, comparative, constructively sceptical, positioned from the bottom up, and collaborative. CONCLUSIONS: This model, or aspects of it, could be extended to the evaluation of other mental health programmes and services that have collaborative elements.

Delivery of Health Care, Integrated↗
PubMed1998

Isolation and partial structure determination of a clonidine-displacing substance from bovine lung and brain.

A large scale extraction and isolation method was developed for the purification of clonidine-displacing substance (CDS) activity from bovine lung or brain. This optimised method used direct freeze drying of tissue, hexane removal of lipids, and methanol extraction of CDS activity. Using a bioassay directed isolation strategy a new CDS compound was purified from an extract of bovine lung. The isolation strategy involved subsequent steps of flash C-18 chromatography, ion exchange, size exclusion, and C-18 HPLC. An HPLC detection method was developed and applied to show that the new CDS is present in both lung and brain tissue. Spectroscopic data for this new CDS indicates that it is related to guanosine, but is not noradrenaline, adrenaline, histamine, agmatine, guanosine, GMP, GDP or GTP.

Adrenergic alpha-Agonists↗
PubMed1996

Carotid artery surgery in the octogenarian.

BACKGROUND: The value of carotid surgery is largely dependent on the safety of the procedure. With changes in population life expectancy, increasing numbers of elderly patients are being considered for surgery. METHODS: In the present paper, the results of 113 patients (octogenarians: > 80 years of age) who underwent carotid endarterectomy in the 17 years prior to 1994 are reported. This group composed 6.2% of the 1818 patients treated in the period, 665 (36.6%) operations were performed on patients 50-65 years inclusive and 1040 (57.2%) on patients aged 66-80 years inclusive. RESULTS: The overall peri-operative stroke rate was 2.5% and the postoperative mortality was 1.9% with no statistical difference apparent between the age groups despite hemispheric strokes being the most common indication for operation in the octogenarian group (29.5%) and the least common indication in the youngest age group (16.2%, P <0.01). Long-term follow up (2-7 years) of octogenarian patients undergoing carotid surgery suggested maintenance of pre-operative levels of living independence. CONCLUSIONS: The results of the study indicated that octogenarian patients should not be denied carotid endarterectomy on the basis of age alone and that results comparable to those of younger patients can be anticipated.

Activities of Daily Living↗
PubMed1992

Colour flow imaging in the detection of femoro-distal graft and native artery stenosis: improved criteria.

Vein graft or native artery stenosis after femoro-distal revascularisation is a common cause of graft occlusion. The early detection and treatment of such stenoses offers the potential for better graft patency than salvage procedures undertaken for graft thrombosis. In the past, two criteria using duplex scanning have been used to detect grafts at risk: (a) a localised increase in the peak velocity (V2) by 100% or more in comparison to the peak velocity (V1) 2 cm upstream (i.e. V2/V1 ratio greater than 2.0), and (b) a decrease in average peak velocity to less than 45 cm s-1. Seventy-four consecutive patients with femoro-distal vein grafts have been studied with intravenous digital subtraction angiography to detect stenosis (greater than 50% diameter) and colour flow imaging using both duplex scanning criteria (a) and (b) at 1.5, 3, 6, 9 and 12 months after operation. The results show that the V2:V1 ratio greater than criterion had a sensitivity of 100% and a specificity of 83%. Stenoses in the native distal arteries were not detected. Low average peak velocity less than 45 cm s-1 had a sensitivity of 61% and a specificity of 98%. By combining both criteria the sensitivity for detecting stenoses in both the vein graft and native distal artery, became 100% and the specificity 98%.

Angiography, Digital Subtraction↗
PubMed1989

Number and anatomical distribution of incompetent thigh perforating veins.

Although incompetent thigh perforating veins are considered to be a common cause of recurrence of varicose veins after high saphenous ligation, the number and distribution of such incompetent veins have not been reported. The aim of the study was to determine the number and anatomical distribution of incompetent thigh perforating veins. Sixty-five limbs in 48 patients with varicose veins who were found to have incompetent thigh perforating veins on ascending deep to superficial venography were studied. In 80 per cent of patients one incompetent thigh perforating vein was found and in 20 per cent more than one was found. Concomitant incompetent calf perforating veins were found in 92 per cent of the limbs studied. The incompetent thigh perforating veins were found to occur anywhere in the thigh, from the upper edge of the patella to a few centimetres below the saphenofemoral junction. The majority (71 per cent) were found in the middle third of the thigh. All incompetent thigh perforating veins were communicating with the long saphenous vein, including those in five patients with incomplete stripping. The surgeon should be aware of incompetent thigh perforating veins which may be multiple and occur at any site on the medial aspect of the thigh.

Adult↗
PubMed1989

Blood flow in the perimalleolar skin in relation to posture in patients with venous hypertension.

The resting and standing perimalleolar skin blood flow and venoarteriolar response have been studied in 20 patients with postphlebitic limbs and 25 normal volunteers using laser-Doppler flowmetry. In postphlebitic limbs the venoarteriolar reflex was impaired and both the resting and standing skin blood flow were increased, suggesting the presence of local vasoparalysis similar to that previously observed in diabetics with peripheral neuropathy.

Ankle↗
PubMed1986

A closed loop microprocessor controller for treatment of hypertension after cardiac surgery.

Hypertension after cardiac surgery is common and requires accurate control by carefully regulated infusions of drugs such as sodium nitroprusside. A microprocessor-based controller has been designed to close the loop between the blood pressure response and the infusion rate of a hypotensive drug. This system has been refined by computer simulation of the blood pressure response to sodium nitroprusside and by experience gained in using the controller in eleven patients in the early recovery period after cardiac surgery. The controller was able automatically to maintain blood pressure within 10% of a specified value. Provision of sophisticated safety features in automatic drug infusion controllers is essential for patient protection.

Cardiac Surgical Procedures↗
PubMed1984

Curative local excision in the treatment of carcinoma of the rectum.

A safe, simple technique of curative local excision is used for early invasive carcinoma of the rectum. Strict criteria were applied in selecting patients for curative local excision: (1) the tumor was less than 3 cm in diameter; (2) there were no clinically involved pelvic lymph nodes; (3) the tumor had a pedicle or pseudopedicle, and (4) subsequent histopathologic examination showed that the tumor was confined to the mucosa and submucosa of the bowel wall and completely excised. Curative local excision in 16 patients had no operative mortality or morbidity. The five-year cancer specific survival was 100 per cent, which compares favorably with the 88 per cent cancer specific survival rate in 268 patients managed by conventional curative resection for Dukes' stage A tumors. When the 7.1 per cent operative mortality of resection was additionally considered, the five-year survival fell to 81 per cent. The probability of lymph-node metastases in primary rectal tumors confined to the mucosa and submucosa was found to be 6.2 per cent irrespective of their diameter, i.e., slightly less than the mortality of resection.

Aged↗
PubMedDate not supplied

Disordered eating and unhealthy weight reduction practices among adolescent females.

BACKGROUND: Dissatisfaction with body weight and the use of unhealthy weight reduction practices have been reported among adolescent females. There is a need for methodologically rigorous studies using large representative samples of adolescent females to accurately assess the prevalence of these behaviors and attitudes. METHODS: Eight hundred sixty-nine Australian school girls ages 14-16 years were administered a self-report questionnaire to determine the prevalence of disordered eating behaviors, unhealthy dieting practices, and distorted body image. Anthropometric (height and weight) data were collected on each of these adolescent females. RESULTS: The prevalences of disordered eating, unhealthy dieting, and distorted body image were 33, 57, and 12%, respectively. Over one-third (36%) of the total sample had used at least one "extreme" dieting method in the past month, i.e., "crash" dieting, fasting, slimming tablets, diuretics, laxatives, and/or cigarettes to lose weight. Of the total sample, 77% wanted to lose weight and 51% had tried to lose weight in the past month. Motivating factors for disordered eating and unhealthy dieting behaviors were peer pressure, media pressure, and the perception that extreme dieting strategies were harmless. CONCLUSION: The prevalence of disordered eating and dieting behaviors among adolescent females shown by this study suggests the need for preventive programs encouraging appropriate eating and dieting behaviors.

Adolescent↗
PubMedDate not supplied

Evaluation of the effects of elastic compression in patients with postphlebitic limbs by laser-Doppler flowmetry.

Laser-Doppler flowmetry has been used to study the skin microcirculation in 20 normal limbs and 80 limbs of patients with venous hypertension and leg ulceration due to deep venous reflux. It was found that limbs with venous hypertension had a high skin resting blood flow (BRF) and an impaired veno-arteriolar reflex (VR). There was a marked improvement in both BRF and VR after elastic compression for three weeks and an association between this improvement and the rate of healing of the leg ulcers. The results indicate that elastic compression may affect the microcirculation even though it does not alter the venous pressure measurements when the elastic stockings are removed.

Adult↗