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S Sarin

Publications and source records attributed to S Sarin.

At least 19 recordsLinked to original sources
PubMed1995

Deficiency in T cell responses of human fetal lymph node cells: a lack of accessory cells.

Lymph node and spleen cells of human foetuses from the 18th to the 24th week of gestation were analysed with regard to their phenotypes and their functional capacities. Fetal mesenteric lymph nodes contain high percentages of CD45RA+ T cells and few B cells and monocytes, whereas the fetal spleen is comprised of equal numbers of T and B cells as well as monocytes/macrophages. Functional analysis of lymph node T cells revealed a lack of proliferative response to PHA or CD3 specific mAb, despite induction of expression of the activation marker CD69. Proliferation of LN cells and thymocytes was observed upon addition of exogenous IL-2. An allogeneic EBV transformed tumour cell line, known to be an effective antigen presenting cell, could induce proliferation of LN cells without exogenous IL-2 and fetal spleen cells could proliferate in response to all stimuli tested without additional IL-2. Splenic non-T cells could restore the proliferation of lymph node cells as efficiently as IL-2 or the EBV transformed B cell line. Separated B cells were more effective than plastic adherent cells on a per cell basis. Naivity of the fetal immune system is therefore not only reflected by the expression of markers representative for naive lymphocytes but can also be due to the absence of potential accessory cells in the different lymphoid organs.

Adult↗
PubMed1994

Stripping of the long saphenous vein in the treatment of primary varicose veins.

Eighty-nine legs with long saphenous vein (LSV) reflux and saphenofemoral junction incompetence were treated by saphenofemoral ligation and multiple avulsions; patients were randomized to undergo additional stripping of the LSV from groin to upper calf (n = 43) or no additional treatment (n = 46). At a median of 21 months after surgery recurrence was evaluated by duplex ultrasonography, photoplethysmography, clinical examination and patient assessment. Fewer persisting incompetent LSVs in the calf were found (21 versus 38) and median (interquartile range) photoplethysmographic refilling times were longer (20 (13-27) versus 14 (11-21) s) when the LSV was stripped than after saphenofemoral ligation alone (both P < 0.1). More patients were completely satisfied (65 versus 37 percent and were recurrence-free (65 versus 17 per cent) when the LSV had been stripped compared with saphenofemoral ligation alone (P < 0.05 and P < 0.001 respectively). The addition of LSV stripping to saphenofemoral ligation and multiple avulsions results in a better overall outcome.

Adult↗
PubMed1994

Plasma elastase in venous disease.

The plasma elastase level was measured as a marker of neutrophil degranulation in three groups, each of 15 patients, with uncomplicated varicose veins, lipodermatosclerosis (LDS) and venous ulceration. The values obtained were compared with those in age- and sex-matched control subjects. Significantly higher levels of elastase were found in all patient groups compared with controls: median 25.6 ng/ml for patients with uncomplicated varicose veins, 22.1 ng/ml for those with LDS, 26.0 ng/ml for those with venous ulceration. There was no difference in neutrophil count between the patient and control groups. These results provide evidence of increased neutrophil degranulation in patients with venous disease. The finding of raised elastase levels in all three patient groups shows that this was not due solely to the inflammatory process characterizing LDS and venous ulceration.

Adult↗
PubMed1994

Duplex ultrasonography for assessment of venous valvular function of the lower limb.

Both legs of 29 patients with venous disease and those of 15 controls without venous disease were assessed by duplex ultrasonography. The duration of reverse flow after release of manual calf compression was measured in the common femoral, long saphenous, popliteal and short saphenous veins. Before undertaking the study, the reproducibility of the technique was evaluated in six subjects by repeating the examination over 3 consecutive days; the coefficient of variation of the test was 7.3 per cent. The 95 per cent confidence interval (c.i.) of the median (0.16 s) of all measurements in the normal limbs was 0.12-0.18 s. The 95 per cent c.i. for the 95th percentile of all measurements in normal limbs was 0.32-0.52 s. In limbs with clinical evidence of venous disease at least one of the sites examined was found to have reverse flow lasting longer than 0.5 s. These data suggest that the measurement of reverse flow after release of manual calf compression is a reproducible technique. While the method records some reverse flow in normal veins, its duration is unlikely to exceed 0.5 s; significant reflux is therefore defined as reverse flow exceeding 0.5 s.

Adult↗
PubMed1994

Differing embryotoxic effects of senecionine and senecionine-N-oxide on the chick embryo.

The embryotoxic properties of pyrrolizidine alkaloids senecionine (water insoluble) and senecionine-N-oxide (water soluble) were examined using the CHEST method (Chick Embryotoxicity Screening Test). The beginning of the embryotoxicity range for senecionine was found to be between 3-30 micrograms; senecionine-N-oxide, on the other hand, showed no effect even with 100 micrograms dose. On the basis of the theoretical calculation, it can be expected that senecionine embryotoxicity for mammals ranges between 10-100 mg/kg maternal body weight, overlapping in this way the known adult toxicity range. The rat LD50 of most alkaloids known to be significant for human health are in the range of 34-300 mg/kg.

Animals↗
PubMed1994

Long-term outcome of patients presenting with acute complications of diverticular disease.

The immediate management of acute diverticular disease is well defined but the risk of further complications and the long-term course of the disease, after conservative or surgical treatment, is not clearly documented. Over an 8-year period, a total of 164 patients (male/female = 69/95, median age 68 years) presented with acute complications of diverticular disease and were prospectively followed up for a median of 48 months. Medical treatment of acute diverticulitis was effective in 85% of 86 patients, with a mortality of 1.3% and a recurrence rate of 2% per patient year follow-up. All 37 patients presenting with bleeding responded to conservative management without mortality and a readmission rate, with further bleeding, of 5% per patient year. Patients who required colonic resection (n = 52), either as a single or staged procedure, had a mortality of 12% but with no further admissions with complications of diverticular disease. The low risk of readmission with recurrent disease after successful conservative treatment of the acute complications of diverticular disease does not justify elective operation in this group of patients.

Acute Disease↗
PubMed1993

When do vascular surgeons prescribe antiplatelet therapy? Current attitudes.

A large number of studies have addressed the efficacy of antiplatelet agents in the prevention of primary and secondary atherosclerotic events. We have undertaken to review the literature and conclude that there is good evidence for the routine prescription of antiplatelet therapy in the prevention of secondary atherosclerotic events in patients with unstable angina, myocardial infarction, transient ischaemic attacks and post-arterial reconstruction. The evidence for any benefit in the prevention of vascular graft occlusion is less clear cut. We therefore conducted a postal survey of Vascular Surgeons in Britain and Ireland, receiving 112 responses to 134 questionnaires. Forty-seven percent of surgeons used antiplatelet therapy following any vascular procedure that they undertook. The rest were more selective in their use of these drugs, reserving them for specific vascular reconstruction, e.g. with synthetic grafts. Five percent of surgeons used anti-platelet aggregating prophylaxis only in patients following transluminal balloon angioplasty. In view of extensive evidence of reduction in long-term vascular mortality and non-fatal vascular events by the use of these drugs in patients who have had a primary vascular event, we would suggest that there is a strong argument for the routine use of anti-platelet drugs in patients presenting with arterial disease to a Vascular Surgeon, regardless of vascular reconstruction, angioplasty or type of graft used.

Angioplasty, Balloon↗
PubMed1993

Does venous function deteriorate in patients waiting for varicose vein surgery?

We have looked at the deterioration in the condition of the lower limbs in a group of 36 patients who were waiting for a median time of 20 months for varicose vein surgery, using clinical examination, colour Duplex scanning and photoplethysmograph (95% refilling times). We found a significant deterioration in this group of patients, with four limbs initially unaffected developing reflux on Duplex scanning, of which three had clinical varicose veins (all four were offered surgery), and of the initial 56 involved limbs, 10 further sources of reflux were found (18%), necessitating alteration of the initial planned surgical procedure. No patient developed deep venous insufficiency or ulceration while on the waiting list, although there was one new case of lipodermatosclerosis. However, had surgery been undertaken after the first assessment, 14 patients (25%) would potentially have required further surgery, although accepting this as justification for allowing patients to wait takes no account of patients suffering or quality of life while waiting for operation.

Adult↗
PubMed1993

Venous ulcers and the superficial venous system.

PURPOSE: The purpose of this study is to identify the anatomic location of venous disease in patients with venous ulceration and chronic venous insufficiency. METHODS: Both limbs of 59 consecutive patients attending the Middlesex Hospital Vascular Laboratory (London, U.K.) with venous ulceration were assessed by color duplex ultrasound scanning to determine the location of venous disease. RESULTS: Isolated deep venous reflux was present in only 12 limbs (15%). A combination of deep and superficial venous reflux was found in 25 limbs (32%), and in 42 limbs (53%) there was only superficial venous reflux. CONCLUSION: In just over half the patients with venous ulceration, the disease is confined to the superficial venous system. This group of patients may benefit from surgical treatment. This study emphasizes the need for vascular laboratory investigation of patients with leg ulceration.

Aged↗
PubMed1992

Mechanism of action of external compression on venous function.

Compression stockings and bandages have been shown to improve venous haemodynamics and may act by reducing venous reflux. The aim of this study was to assess the mechanism of action of compression therapy on venous function and to determine whether such treatment may correct valvular incompetence. Both lower limbs of 36 patients (median age 59 (interquartile range 45-65) years) were assessed by duplex ultrasonographic scanning. There were 17 limbs with popliteal vein reflux, 19 with long saphenous vein (LSV) reflux and 21 with short saphenous vein (SSV) reflux. A water-filled adjustable pressure cuff was applied around the knee and inflated gradually, while continuously assessing the veins for reflux using ultrasonographic imaging. The external pressure applied by the cuff was noted when reflux was abolished or when the vein was completely occluded. In four (24 per cent) of 17 popliteal veins, eight (42 per cent) of 19 LSVs and three (14 per cent) of 21 SSVs reflux was abolished before occlusion of the vein. The cuff pressures required to achieve restoration of valvular function were significantly lower than those required to occlude the veins. It is possible, in some refluxing veins, to correct valvular dysfunction by external compression therapy. Coaptation of valvular cuffs to restore valvular competence may be the mechanism of action of compression therapy in venous disease.

Aged↗
PubMed1992

Assessment of stripping the long saphenous vein in the treatment of primary varicose veins.

Stripping of the long saphenous vein (LSV) may prevent recurrence of varices, although this has not been demonstrated using objective criteria. The aim of this study was to determine whether the addition of LSV stripping, from groin to upper calf, to saphenofemoral junction (SFJ) ligation prevents residual reflux, and whether LSV stripping to the upper calf results in greater neurological complications. Sixty-nine patients with primary varicose veins, LSV reflux and SFJ incompetence, confirmed by duplex ultrasonography and photoplethysmography, were studied. A total of 105 limbs were treated by SFJ ligation and avulsion of varices; patients were randomized to undergo stripping of the LSV to the upper calf (n = 49) or no additional treatment (n = 56). Three months after surgery all patients were examined clinically, by duplex ultrasonography and by photoplethysmographic tests of venous function, to establish the extent of persisting varices. Fewer persisting incompetent LSVs in the calf were found when the LSV was stripped (n = 9) than after SFJ ligation alone (n = 25) (P < 0.01). Photoplethysmographic refilling times were improved to a similar extent in both groups after surgery but were lower in those who had residual LSV reflux (P < 0.05). Six limbs developed paraesthesia in the distribution of the saphenous nerve: two in the group that were stripped and four in those that were not. These data suggest that LSV reflux is more completely abolished by combining LSV stripping with SFJ ligation; stripping the LSV to the upper calf does not result in a higher incidence of injury to the saphenous nerve.

Aged↗
PubMed1992

Leg ulcers.

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Humans↗
PubMed1992

Photoplethysmography: a valuable noninvasive tool in the assessment of venous dysfunction?

We have investigated the photoplethysmography findings in 152 patients admitted to the Middlesex Hospital Vascular Laboratory with suspected lower limb venous disease, and we compared the results obtained with patient grouping using clinical criteria and the presence of reflux on color duplex scanning. All photoplethysmography traces were normalized with use of computer software to enable direct comparison between the traces. The parameters investigated were the 95% and 50% refilling times and the initial gradient of the refilling curve. Receiver operating characteristic curves were constructed to determine which parameter was the most useful predictor of disease and to identify which value within each observation gave the greatest sensitivity and specificity. We found a large overlap between interquartile values for all three parameters, with limbs grouped both clinically and by duplex scanning, making differentiation between normal and abnormal limbs difficult on the basis of photoplethysmography traces alone. We found that a 95% refilling time of less than 15 seconds indicated venous dysfunction with the greatest sensitivity and specificity and suggest that this value is most useful. Photoplethysmography readings are reproducible, noninvasive, and correlate well with the presence of clinical disease, and photoplethysmography remains useful in the assessment of venous dysfunction.

Adult↗
PubMed1992

Medial calf perforators in venous disease: the significance of outward flow.

The role of medial calf perforators in the initiation or promotion of venous disease is incompletely understood. The purpose of this study was to define the direction of blood flow in the perforating vein of the calf in normal limbs and in those limbs of patients with venous disease under defined laboratory conditions. Both lower limbs of 57 patients, (32 women and 25 men, median age, 56 years; range, 40 to 62 years) were examined by duplex ultrasonography. In 10 patients no clinical or duplex evidence existed of venous disease. In 60 legs we found evidence of superficial venous insufficiency, complicated by lipodermatosclerosis in 29. In 15 limbs we found deep venous insufficiency. Finally, in 19 limbs no evidence existed of venous disease, but venous reflux was present in the contralateral limb. The direction of blood flow in the medial calf perforators was assessed during compression of the foot and calf, by a cuff that inflated to 60 mm Hg. Blood flow was also assessed during deflation of the cuff. We found that the direction of blood flow within medial calf perforators can be both inward or outward, even in limbs without evidence of venous disease. Outward flow could be demonstrated in 21% of perforators in normal limbs. Flow on release of distal compression occurred in 33% to 44% of perforators in limbs with evidence of venous disease but in none of the perforators in limbs without evidence of venous disease. We found that flow, during the relaxation phase, within medial calf perforators was associated with venous disease elsewhere in the limb.

Adult↗