Renal artery stenosis: evaluation with intravenous digital subtraction angiography

The ability of diagnostic intravenous digital subtraction angiography (IVDSA) to demonstrate the degree of renal artery stenosis was compared with that of intraarterial angiography in 45 patients with 92 arteries. Stenotic lesions on both IVDSA and intraarterial studies were classified as normal (0% stenosis), minor (less than 50%), low grade (50%-80%), and high grade (80%-99%). There was agreement about the degree of stenosis in 90% of the cases. IVDSA grading was correct in 94% of atheromatous lesions and in 56% of the fibromuscular dysplastic lesions. In the high-grade atheromatous lesions, the degree of stenosis was slightly overestimated on IVDSA studies in 22.5% of the cases. In fibromuscular dysplasia, stenosis was underestimated in 33% of the cases.     

Differential effects of U46619 on renal regional hemodynamics in the rat: involvement of endothelin

Many vasoactive agents produce qualitatively similar effects on blood flow in the renal cortex and medulla, evoking reductions or increases in blood flow in both regions. We demonstrated previously that endothelin-1 (ET-1) is an exception because it evoked an increase in medullary perfusion despite a potent cortical vasoconstriction ( Hercule and Oyekan 2000). We report here that U46619 (11,9 epoxymethano-prostaglandin H2), a selective agonist of prostaglandin H2 (PGH2)/thromboxane A2 (TxA2) (TP) receptor, evokes similar effects as ET-1. In the pentobarbital-anesthetized (60 mg/kg) rat, 1, 3, and 5 microg/kg U46619 dose dependently reduced mean arterial blood pressure by -2 +/- 4, -8 +/- 10, and -31 +/- 10 mm Hg, respectively; renal cortical blood flow (CBF) by -50 +/- 11, -174 +/- 45, and -349 +/- 43 perfusion units (PU), respectively; but increased medullary blood flow (MBF) by 42 +/- 16, 51 +/- 18, and 61 +/- 21 PU, respectively. Prostaglandin F2alpha, a TxA2 mimetic, produced similar effects as U46619. SQ29548 ([1S-[1alpha,2alpha(Z), 3alpha,4alpha]]-7-[3[[2-[(phenylamino)carbonyl[hydrazino] methyl]-7-oxabicyclo[2.2.1]hept-2-yl]-5-heptenoic acid) (0.1 mg/kg), an antagonist of PGH2/TxA2 (TP), blunted U46619-induced hemodynamic changes without affecting that produced by phenylephrine. BMS182874 [5-(dimethylamino)-N-(3,4-dimethyl-5-isoxazolyd)-1-naphthalene sulfonamide] (40 mg/kg), an ET(A)-selective antagonist, blunted U46619-induced reduction in CBF by 54 +/- 9% (p < 0.05) and the increase in MBF by 59 +/- 18% (p < 0.05). Similarly, BQ788 (N-cis 2,6-dimethylpiperidinocarbonyl-L-gamma-methylleucyl-D-1-methoxycarbonyltryptophanyl-D-norleucine) (1 mg/kg), an ET(B)-selective antagonist, blunted the effects of U46619 on CBF and MBF by 19 +/- 3% (p < 0.05) and 48 +/- 19% (p < 0.05), respectively. Combined administration of BMS182874 and BQ788 further attenuated U46619-induced reduction in CBF by 67 +/- 8% (p < 0.05) and that on MBF by 61 +/- 18% (p < 0.05). Phosphoramidon (10 mg/kg), an endothelin converting enzyme inhibitor, markedly blunted U46619-induced changes on CBF and MBF (p < 0.05). These findings are the first to demonstrate that U46619, through activation of ET(A) and ET(B) receptors, elicits renal cortical vasoconstriction and medullary vasodilation in the rat.     

An assessment of peripheral vascular disease in patients with diabetic foot ulcer

BackgroundPeripheral vascular disease (PVD) is a chronic limb ischaemia caused by atherosclerosis of the peripheral arteries. Diabetes mellitus is a risk factor for this disease. The most common symptom of PVD is muscle pain in the lower limbs on exercise. In diabetes, pain perception may be blunted by the presence of peripheral neuropathy. Therefore, a patient with diabetes and PVD is more likely to present with an ischaemic ulcer or gangrene than a patient without diabetes. The use of ankle-brachial-pressure index (ABI) in the clinic and bedside provide a measure of blood flow to the ankle. This could help early detection, initiate early therapy and may thus reduce the risk of critical limb ischaemia and limb loss.ObjectiveThe purpose of this study is to evaluate the occurrence of peripheral vascular disease using ankle-brachial index in diabetic patients with and without foot ulcers and the risk factors associated with diabetic foot ulcer (DFU).MethodThis prospective study involved all type 2 DM patients with foot ulcer (DFU population) and those without foot ulcers (non-DFU population) seen in our hospital. Their demographic, clinical and laboratory parameters were noted and documented. Measurement of ABI was done using a portable hand held Doppler and ankle pressures < 0.9 is suggestive of PVD.ResultsA total of 74 patients were recruited. Males were 42 (56.8%) and females were 32 (43.2%). The mean age of the patients was 62.89 ± 10.66 years and the duration of diabetes was 7.61 ± 7.57 years. Forty-six (62.2%) presented with foot ulcer while 28 (37.8%) were without foot ulcer. Patients with PVD represented by ABI < 0.9 was DFU 31(76.4%) while in non-DFU it was 10 (13.4%). Multivariant analysis of variables associated with DFU in those with ABI < 0.9 showed correlation with tobacco use r = .235, p = 0.044; duration of diabetes r = ?.427; p = 0.001; and systolic blood pressure r = ?.301; p = 0.009.DiscussionThe occurrence of PVD determined by the absence of >2 pulses by palpation alone and using ABI was 25.7% and 55.4% respectively. This suggests that assessment by palpation is subjective while the use of Doppler is quantitative and more reliable. DFU patients with PVD showed a significant correlation with tobacco use, duration of diabetes and systolic blood pressure but not with dyslipidaemia.ConclusionThis study shows that these patients had risk factors for PVD. The use of hand held Doppler will aid early diagnosis of critical limb at risk of loss and help to prevent and reduce the high rate of limb loss in our patients.     

Evaluation of the antiplasmodial and cytotoxicity potentials of husk fiber extracts from Cocos nucifera, a medicinal plant used in Nigeria to treat human malaria

Nigeria is an African country where transmission of malaria occurs all year round and where most inhabitants use plants as remedies against parasitic diseases, including malaria. Some of such medicinal plants have their antimalarial efficacies already demonstrated experimentally, active compounds isolated and the mechanism of drug action suggested. Decoction of Cocos nucifera husk is used in the middle belt region of Nigeria as an antimalarial remedy. In our current studies, we tested extracts from husks of four varieties of C. nucifera, all collected in Brazil, where the plant fruit is popularly named 'coco'. The husks of coco mesti?o, amarelo, an?o and gigante collected in the Northeast of Brazil were used to prepare extracts at the Chemistry Department, Federal University of Alagoas (UFAL), which were then tested for their antiplasmodial activities, cytotoxicities and hemolytic activities in vitro. Only the hexane extract of coco mesti?o was active against the blood forms of Plasmodium falciparum human malaria parasite maintained in continuous culture. Most extracts presented selectivity indices of <10, while hexane extract of coco mesti?o had a selectivity index of 35, meaning that the extract is not toxic. The isolation of the active compounds from coco mesti?o husks has not yet been done.     

The highest battlefield of the world : Medical problems and solutions

The Indian Armed Forces Medical Services has been engaged in providing medical to the soldiers serving on Siachen Glacier for the last 25 years. This paper attempts to highlight the medical problems faced by troops on the world's highest battlefield as perceived by a medical officer located on the forward most medical echelon on Siachen Glacier. The medical problems on the glacier include high altitude pulmonary oedema, acute mountain sickness, frost bite chilblains, hypothermia, snow blindness, injury non enemy action due to avalanches, crevasses and fires, carbon monoxide poisoning and problems in disposal of nightsoil. A large number of problems are taken care of by following a well documented acclimatisation drill. However under such conditions providing medical support is a difficult task and requires innovations and improvisations entailing a high degree of mental mobility on the part of medical commanders and the Regimental Medical Officers located on the forward posts.