Coexistence of superconductivity and ferromagnetism in Sr0.5Ce0.5FBiS2-xSex (x = 0.5 and 1.0), a non-U material with Tc < TFM.

We have carried out detailed magnetic and transport studies of the new Sr0.5Ce0.5FBiS2-xSex (0.0 ≤ x ≤ 1.0) superconductors derived by doping Se in Sr0.5Ce0.5FBiS2. Se-doping produces several effects: it suppresses semiconducting-like behavior observed in the undoped Sr0.5Ce0.5FBiS2, the ferromagnetic ordering temperature, TFM, decreases considerably from 7.5 K (in Sr0.5Ce0.5FBiS2) to 3.5 K and the superconducting transition temperature, Tc, gets enhanced slightly to 2.9-3.3 K. Thus in these Se-doped materials, TFM is marginally higher than Tc. Magnetization studies provide evidence of bulk superconductivity in Sr0.5Ce0.5FBiS2-xSex at x ≥ 0.5 in contrast to the undoped Sr0.5Ce0.5FBiS2 (x = 0) where magnetization measurements indicate a small superconducting volume fraction. Quite remarkably, as compared with the effective paramagnetic Ce-moment (~2.2 µB), the ferromagnetically ordered Ce-moment in the superconducting state is rather small (~0.1 µB) suggesting itinerant ferromagnetism. To the best of our knowledge, Sr0.5Ce0.5FBiS2-x Sex (x = 0.5 and 1.0) are distinctive Ce-based bulk superconducting itinerant ferromagnetic materials with Tc < TFM. Furthermore, a novel feature of these materials is that they exhibit a dual and quite unusual hysteresis loop corresponding to both the ferromagnetism and the coexisting bulk superconductivity.

Use of tenecteplase for left-sided prosthetic valve thrombosis.

INTRODUCTION: Prosthetic valve thrombosis (PVT) following cardiac valve replacement in rheumatic heart disease patients is a common cause for referral to tertiary care centre. Although surgery has been described as the traditional choice of therapy, thrombolytic therapy has reported high success rates in published literature. CASE REPORT: This is a case report of ten patients with left-sided PVT receiving tenecteplase. The mean dose of tenecteplase used was 1.01 mg/kg given as IV bolus injection along with enoxaparin, heparin and acenocoumarol. The diagnosis and response was assessed based on trans-thoracic echocardiography. The reduction in peak transvalvular gradient was in the range of 46% - 81% and in mean transvalvular gradient was in the range of 50% - 84%. There was normalization of valve motion in all patients. There was no incidence of mortality, intracerebral hemorrhage, systemic bleeding or embolism. CONCLUSION: To our knowledge, this is the largest published evidence so far showing efficacy and safety of tenecteplase for PVT.

Risk factors for ischemic heart disease in Delhi. (A prospective study of 7000 cases).

BACKGROUND: A prospective study of 7000 consecutive patients with IHD was carried out for "traditional" risk factors at the National Heart Institute (NHI) of the All India Heart Foundation (AIHF) and compared with 1000 "normal" controls. A specially designed proforma was used. STUDY GROUP: There were 5334 men (76%) and 1666 women (24%). The ages ranged from 24 to 92 years; above 60 (35%), between 51-60 (23%), 41-50 (22%) and below 40 (21.7%). The risk factor profile for the whole group was positive family history 38%, sedentary lifestyle 56%, overweight & obesity 21%, hypertension 64%, smoking 43% diabetes 39%, hypercholesterolemia 21% with no obvious risk factor in 15%. Those with no obvious risk factors could have had some of the "new" ones, which were not addressed. 2 & 3 risk factors were present in the majority (5618 patients 80%) and multiple risk factors in 96%. Hypertension was dominant in all groups. WOMEN: Significant differences were more, sedentary lifestyle, little or no smoking, higher cholesterol and more with no obvious risk factors. PRECOCIOUS IHD: In the 22% below 40 years, there was a significantly higher family history and smoking with significant prevalence of smoking, hypertension and diabetes. EXECUTIVE GROUP: The ages ranged from 24 to 59 with none above 60. There was no obvious risk factor in 55%. Here was a positive family history in 30.8%, sedentary lifestyle in 34%, smoking in 24.7%, hypertension in 16.5%, diabetes 11.8% and high cholesterol only in 5.6%. CONCLUSION: Multiple traditional risk factors were dominant in all the groups, with hypertension heading the list. Control of these, should be the target for all preventive programmes, targeting the general population and high risk groups.

Mg2+: a potent inhibitor of collagen-induced in vitro mineralization.

At physiological concentrations, Mg2+ has been found to be a potent inhibitor of collagen-induced in vitro mineralization. Mg2+ inhibits mineralization by competing with Ca2+ for specific phosphate independent Ca2+ binding sites of the catalytic matrix. Matrix bound Mg2+ subsequently reacts with HPO4(2-) to form MgHPO4 complex which can not be further converted to the matrix bound mineral phase. The matrix, as well as the mineral phase associated with the matrix, influence the rate of mineralization.

Jaccoud's arthropathy--diagnostic and therapeutic implications.

A case of isolated chronic severe aortic regurgitation with Jaccoud's arthropathy involving the foot is presented. The interesting feature of the case is the absence of history of acute rheumatic arthritis at any stage of the illness. The diagnostic and possible therapeutic significance of this otherwise uncommon and benign condition are discussed.

Acute effect of ethanol administration on platelet function.

The acute effect of single dose of ethanol (1.5 g kg) and aspirin (10 mg/kg) alone and in combination, on platelet aggregation time and platelet adhesiveness were studied in rabbits. There was a significant and comparable increase in aggregation time both by aspirin and ethanol. Similarly platelet adhesiveness was decreased by both the agents.

Status of platelet functions in volunteers of various blood groups: effect of aspirin.

Platelet functions (platelet aggregation and adhesiveness) were studied in volunteers of different blood groups. The platelet aggregation time was found to be significantly (P less than 0.01) more in blood group O as compared A, B and AB blood groups. Similarly, platelet adhesive index was higher in A, B and AB blood groups when compared to that of blood group O. The administration of a single dose of aspirin (4 mg/kg, po) increased the platelet aggregation time and reduced the platelet adhesive index in all the blood groups.

Enhanced platelet aggregation by oral contraceptives: effect of PG synthetase inhibitors.

Platelet aggregation time was significantly (P less than 0.01) decreased in female rabbits treated with oral contraceptive (a preparation containing low dose of estrogen) as also by injection of diethylstilbestrol (10 mg/kg), while in animals that received indomethacin (10 mg/kg) or aspirin (30 mg/kg) (PG synthetase inhibitors) along with oral contraceptives or diethylstilbestrol there was no significant alteration in platelet aggregation time. The increased synthesis of prostaglandins or some of the intermediary product like TXA2 might be responsible for this effect.