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Biomedical subjects

A Rehman

Publications and source records attributed to A Rehman.

At least 19 recordsLinked to original sources
PubMed2007

Influence of the Angiotensin II type I receptor gene 1166A > C polymorphism on BP and aortic pulse wave velocity among Malays.

Angiotensin II type 1 receptor (AGT1R) gene 1166A > C polymorphism has been shown to be associated with essential hypertension and aortic stiffness as measured by carotid femoral pulse wave velocity (PWV). This study was carried out to investigate the association of the 1166A > C polymorphism with blood pressure (BP) and PWV among Malay hypertensive and normotensive subjects. Two hundred and one hypertensive subjects without evidence of cardiovascular (CV) complications and 201 age- and sex-matched normotensive subjects were studied in a cross-sectional design. Blood pressures (BP) and PWV were measured, and 1166A > C genotype was determined by polymerase chain reaction followed by restriction enzyme digestion. The 1166C allele frequency was 7.96% and 7.73% among Malay hypertensive and normotensive subjects, respectively. There was no association of the 1166A > C polymorphism with BP in the hypertensive, normotensive or overall Malay populations. PWV was significantly higher among 1166C allele carriers as compared to non-carriers (10.52 +/- 1.82 vs. 10.15 +/- 1.80, p = 0.040) in the overall population, but not in the hypertensive and normotensive populations separately. In conclusion, the frequency of 1166C polymorphism is similar among Malay hypertensive and normotensive subjects. This polymorphism has no association with BP but may have an influence on PWV in Malays, which needs further investigation.

Aged↗
PubMed2006

The low incidence of surgery for non-cardiac vascular disease in UK Asians may be explained by a low prevalence of disease.

AIMS: Firstly, to compare rates of surgery for non-cardiac vascular disease in Caucasians and Asians and secondarily to assess the prevalence of peripheral arterial disease (PAD) and abdominal aortic aneurysm (AAA) in the male UK Asian population. METHODS: Analysis of a prospective database followed by an epidemiological survey of 100 unselected Pakistani males, in which demographic and anthropometric data were collected alongside aortic ultrasonography and measurement of ankle: brachial pressure index (ABPI). RESULTS: Although 14.1% of our catchment area is Asian, after correction for age, they only accounted for 64/2268 (2.8%) of procedures for PAD and AAA. Specifically, Asians were 10 times less likely to undergo AAA repair and 3 times less likely to undergo procedures for lower limb peripheral bypass, amputation and endovascular intervention. In the epidemiological study, 26 subjects had a significant history of ischaemic heart disease, 21 were diabetic, 32 had hypertension and 60 were current or ex-smokers. Median aortic diameter [IQR] was 17.6 mm [16.3-19.1 mm] and no subject had an AAA. In 200 limbs, median ABPI [IQR] was 1.12 [1.04-1.21]. Only 2 patients had an ABPI < 0.9. CONCLUSION: Despite a high prevalence of cardiovascular risk factors and ischaemic heart disease, the prevalence of PAD and AAA is much lower than would have been expected in an age- and sex-matched Caucasian population. These data suggest that the reduced incidence of surgery for PAD and AAA in UK Asians is due to a low prevalence of disease.

Aged↗
PubMed2003

External iliac endofibrosis in endurance athletes: a novel case in an endurance runner and a review of the literature.

BACKGROUND: There is increasing recognition that high-performance athletes can develop symptomatic arterial flow restriction in one or both (15%) legs due to kinking and/or endofibrosis of their iliac arteries. METHODS: Case report and review based on a Medline search of the literature. RESULTS: A 51-year-old female, 24-hour endurance runner presented with a six-month history of rapidly progressing intermittent claudication affecting her right thigh and calf in the absence of classical risk factors for atherosclerosis. On the basis of invasive and non-invasive investigations, a provisional diagnosis of endofibrosis was made and she was treated successfully with angioplasty. CONCLUSIONS: The epidemiology, optimal investigation and treatment of iliac endofibrosis in endurance athletes is poorly described. Each individual unit's experience is likely to be very small. A European register of such cases would increase our understanding of the condition and improve patient outcomes.

Angioplasty↗
PubMed2003

The utilisation of superficial venous surgery for chronic venous insufficiency by the U.K. Asian population.

BACKGROUND: The epidemiology of superficial venous disease is relatively well defined in the U.K. Caucasian population. By contrast, there are currently no data available for Asians, who comprise 3.6% of the U.K., and 14.1% of this institution's catchment population. The aim of this study was to compare surgery for superficial venous disease in Caucasians and Asians in this institution, in the context of our local population. METHODS: A prospectively gathered database of all 2011 superficial venous operations performed between January 1997 and April 2002 was retrospectively analysed with regard to ethnicity. The ethnic, gender and age composition of our catchment area was determined from U.K. census data. The full institutional records of 100 Asian and 100 randomly selected age and sex-matched Caucasian patients were compared in a case control study. RESULTS: After adjusting for age and gender according to census data, Asians were 40% less likely to undergo superficial venous surgery (SVS). Considering the 2011 operated patients as a whole, Asians were significantly younger and more likely to be male. In the case control study, Asians were significantly less likely to be operated for recurrent disease and significantly more likely to be operated for advanced disease. CONCLUSIONS: Although Asians are significantly less likely to undergo SVS; those that do are more likely to be young, male and operated for skin changes and ulcers. This strongly suggests that the under-representation of Asians is due to cultural, genetic or environmental factors and unmet health care need, rather than a lower prevalence of clinically significant venous disease in the Asian population.

Adult↗
PubMed2003

Vitamin E and its effect on arterial stiffness in postmenopausal women--a randomized controlled trial.

INTRODUCTION: Arterial stiffness is emerging as a useful index of vascular health. Postmenopausal women have been shown to have stiffer arteries. Hormone replacement therapy and soy isoflavones improve arterial stiffness in these women. The aim of this study is to establish whether vitamin E improves arterial stiffness in postmenopausal women after 10 weeks of supplementation. METHODS: Twenty postmenopausal women with a mean age of 54.59 +/- 1.22 years participated in this randomized, crossover, double-blind, placebo-controlled clinical trial. All women received 400 IU of tocopherol daily for 10 weeks or a placebo capsule, before being crossed over for treatment. At intervals of 5 weeks, subjects attended sessions where measurements of arterial stiffness, blood pressure and plasma vitamin E level were taken. Pulse wave velocity measurement, using the automated Complior machine, was used as an index of arterial stiffness. RESULTS: Plasma vitamin E level was 30.38 +/- 1.56 micromol/l at baseline, after treatment it was 59.01 +/- 3.30 micromol/l and 31.17 +/- 1.37 micromol/l with vitamin E and placebo, respectively (p < 0.001). There was no significant difference in pulse wave velocity after 10-week treatment with placebo and vitamin E (9.14 +/- 0.29 versus 9.04 +/- 0.29 m/s, respectively). Similarly, no difference in systolic and diastolic blood pressure was seen between placebo and vitamin E at the end of 10 weeks. CONCLUSION: Supplementary vitamin E for 10 weeks at 400 IU daily has no effect on arterial stiffness in healthy postmenopausal women.

Antioxidants↗
PubMed2002

Effect of angiotensin II on pulse wave velocity in humans is mediated through angiotensin II type 1 (AT(1)) receptors.

The objective of this study was to examine the effect of angiotensin II (Ang II) and angiotensin II type 1 (AT(1)) receptor blockade on pulse wave velocity (PWV) in healthy humans. We studied nine young male volunteers in a double-blind randomised crossover design. Carotid-femoral PWV (an index of arterial stiffness) was measured by using a Complior machine. Subjects were previously treated for 3 days with once-daily dose of either a placebo or valsartan 80 mg. On the third day, they were infused with either placebo or 5 ng/kg/min of Ang II over 30 min. Subjects thus received placebo capsule + placebo infusion (P), valsartan + placebo infusion (V), placebo + Ang II infusion (A), and valsartan + Ang II infusion (VA) combinations. Heart rate (HR), blood pressure and PWV were recorded at baseline and then every 10 min during infusion and once after the end of infusion. There were significant increases in systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) with A compared with P (P = 0.002, P = 0.002, P = 0.001 respectively). These rises in blood pressure were completely blocked by valsartan. A significant rise in PWV by A was seen compared with P (8.38 +/- 0.24 vs 7.48 +/- 0.24 m/sec, P = 0.013) and was completely blocked by valsartan; VA compared with P (7.27 +/- 0.24 vs 7.48 +/- 0.24 m/sec, P = NS). Multiple linear regression analysis showed that blockade of Ang II induced increase in blood pressure by valsartan contributed to only 30% of the total reduction in Ang II induced rise in PWV (R(2) = 0.306). The conclusions were that valsartan completely blocks the effect of Ang II on PWV. The effect of Ang II on PWV is mediated through AT(1)receptors. Reduction in PWV by Ang II antagonist is not fully explained by its pressure lowering effect of Ang II and may be partially independent of its effect on blood pressure.

Adult↗
PubMed2001

The cloning of a rat peptidoglycan recognition protein (PGRP) and its induction in brain by sleep deprivation.

Peptidoglycan recognition protein (PGRP) binds to peptidoglycan (PG) or live bacteria and is upregulated by PG. PGRP is a ubiquitous protein involved in innate immunity. Tag7, a novel cytokine, is also induced by bacterial products; tag7 is apoptotic to murine L929 cells in a NF-kappaB-independent manner. Both of these genes are expressed in brain, lymphatic and haematopoietic tissues. We provide evidence that murine PGRP and tag7 encode identical transcripts and have structural relationships to lysozymes. Further, we have cloned the cDNA of rat PGRP and analyzed its expression in brains of sleep-deprived and control rats. The mRNA levels of PGRP/tag7 were measured by RT-PCR and compared to the housekeeping gene porphobilinogen deaminase (PBD). PGRP was constitutively expressed in rat brain. PGRP mRNA was increased by 43% and 17% in the brainstem and hypothalamus, respectively, in sleep-deprived rats compared to controls. The upregulation of PGRP expression by sleep deprivation suggests a role for PGRP in a homeostatic regulation of sleep.

Amino Acid Sequence↗
PubMed2001

Short-term comparative outcomes associated with the use of GP IIb/IIIa antagonists in patients undergoing coronary intervention.

BACKGROUND: Platelet glycoprotein (GP) IIb/IIIa antagonists reduce the occurrence of death, myocardial infarction (MI) and urgent revascularization among patients undergoing percutaneous coronary intervention (PCI). Despite a similar mechanism of platelet inhibition, the three currently approved agents vary widely in cost. PURPOSE: The purpose of this prospectively designed, retrospective analysis was to determine clinical outcomes for patients receiving abciximab, tirofiban or eptifibatide as adjunctive therapy during PCI at a single center. We hypothesized that there would be no difference in outcomes during hospitalization following PCI in patients receiving tirofiban or eptifibatide compared with those patients who received abciximab. Outcomes examined included in-hospital mortality, hemorrhagic procedural complications, need for recatheterization, peak creatine kinase following intervention and length of hospital stay (LOS). RESULTS: Two hundred and sixty seven consecutive patients in whom GP IIb/IIIa antagonist therapy was initiated in the catheterization laboratory for PCI were analyzed. Abciximab-treated patients were more likely to be undergoing primary (p<0.001) and rescue (p=0.022) PCI and to have received fibrinolytic therapy (p=0.013) when compared to patients receiving tirofiban or eptifibatide. There were no significant differences between abciximab- and non abciximab-treated patients in either the primary PCI or non primary PCI groups in any of the studied endpoints. In patients undergoing primary PCI, abciximab-treated patients when compared with non abciximab-treated patients exhibited a trend toward an increase in hospital LOS (7.8+/-7.0 d vs 6.2+/-3.9, p=0.19) and in the frequency of hemorrhagic complications (22.1% vs 5.3%, p=0.11). In patients not receiving fibrinolytic therapy, abciximab-treated patients experienced a trend toward increased hemorrhagic complications following PCI when compared to non abciximab-treated patients (10.2% vs 6.0%, p=0.28). Complications distant from the vascular access site comprised 62.5% of hemorrhagic complications in the abciximab-treated group, but only 20% of the complications in the non-abciximab treated population (p<0.001). These data suggest no differences in acute outcomes between groups of patients receiving abciximab or other approved GP IIb/IIIa antagonists highlighting a potential significant cost saving. These data will require interpretation following the publication of comparative trials.

Abciximab↗
PubMed2001

Paraneoplastic limbic encephalitis associated with bronchogenic carcinoma: a case report.

Paraneoplastic limbic encephalitis is a rare clinical entity, associated most often with the oat cell carcinoma of the lung. Clinically, it presents with affective changes in personality, memory loss, confusional state, hallucinations, and seizures; with dementia being the common feature as the disorder progresses. Response to treatment is disappointingly poor.

Carcinoma, Bronchogenic↗
PubMed2001

The effects of angiotensin II on pulse wave velocity in healthy humans.

OBJECTIVES: To examine the dose response relationship between Ang II and pulse wave velocity (an index of arterial stiffness) in healthy human volunteers. DESIGN AND METHODS: We studied 9 healthy male volunteers (mean age 24.7 +/- 0.66 years) in a double-blind, randomized, cross-over, placebo-controlled design. We measured carotid-femoral PWV using a novel device complior. Subjects received placebo, 0.5, 1 and 5 ng/kg/min Ang II as infusions over 30 minutes under standardized conditions. Heart rate, blood pressure and PWV were recorded at baseline and then every 10 minutes during the infusion and twice after the end of the infusion. RESULTS: Systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) in mmHg increased significantly with the 5 ng/kg/min dose compared to placebo (p = 0.004, p -0.007, p = 0.003, respectively). There was no significant difference in SBP, DBP and MAP between 1 and 0.5 ng/kg/min compared to placebo. There was a significant increase in PWV with 5 ng/kg/min dose only compared to placebo (p = 0.02). However, less than 30% of the total Ang II-induced rise in PWV was explained by the Ang II-induced rise in blood pressure (R2 = 0.257). CONCLUSIONS: Ang II increases PWV in healthy human only when given in doses that significantly increase blood pressure. Not all the increase in Ang II-induced rise in PWV can be explained due to Ang II-induced rise in BP.

Adult↗
PubMed2000

Potential problems of ascorbate and iron supplementation: pro-oxidant effect in vivo?

The comparison was undertaken between the effects of ascorbate versus ascorbate plus iron supplementation on DNA damage. Twenty healthy subjects with initial levels of plasma ascorbate of 67.2 +/- 23.3 micromol/l were randomly assigned to and cycled through one of three supplementation regimes: placebo, 260 mg/d ascorbate, 260 mg/d ascorbate plus 14 mg/d iron for 6 weeks separated by 8-week washout periods. Supplementation did not cause a rise in total oxidative DNA damage measured by GC-MS. However, a significant decrease occurred in levels of 8-oxo-7,8-dihydroguanine by ascorbate supplementation and 5-hydroxymethyl uracil by both ascorbate and ascorbate plus iron supplementation, relative to the pre-supplemental levels but not to the placebo group. In addition, levels of 5-hydroxymethyl hydantoin and 5-hydroxy cytosine increased significantly, only relative to pre-supplementation, by ascorbate plus iron treatment. No compelling evidence for a pro-oxidant effect of ascorbate supplementation, in the presence or absence of iron, on DNA base damage was observed.

Adult↗
PubMed2000

Preparation of a protected triamino analogue of cholic acid and sequential incorporation of amino acids in solution and on a solid support.

We have prepared a triamine derivative of cholic acid with protecting groups on the amines that allow sequential amide formation. The triamine was formed from 3 alpha,7 alpha, 12 alpha-trihydroxycholan-24-ol with good stereoselectivity. Sequential removal of the amine protecting groups and amide formation was achieved in high-yielding steps and was performed in solution and on a solid support.

Amides↗