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Biomedical subjects

V Sahni

Publications and source records attributed to V Sahni.

At least 19 recordsLinked to original sources
PubMed2007

Formyl peptide receptors and the regulation of ACTH secretion: targets for annexin A1, lipoxins, and bacterial peptides.

The N-formyl peptide receptors (FPRs) are a family of G-protein coupled receptors that respond to proinflammatory N-formylated bacterial peptides (e.g., formyl-Met-Leu-Phe, fMLF) and, thus, contribute to the host response to bacterial infection. Paradoxically, a growing body of evidence suggests that some members of this receptor family may also be targets for certain anti-inflammatory molecules, including annexin A1 (ANXA1), which is an important mediator of glucocorticoid (GC) action. To explore further the potential role of FPRs in mediating ANXA1 actions, we have focused on the pituitary gland, where ANXA1 has a well-defined role as a cell-cell mediator of the inhibitory effects of GCs on the secretion of corticotrophin (ACTH), and used molecular, genetic, and pharmacological approaches to address the question in well-established rodent models. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis identified mRNAs for four FPR family members in the mouse anterior pituitary gland, Fpr-rs1, Fpr-rs2, Fpr-rs6, and Fpr-rs7. Functional studies confirmed that, like dexamethasone, ANXA1 and two ANXA1-derived peptides (ANXA1(1-188) and ANXA1(Ac2-26)) inhibit the evoked release of ACTH from rodent anterior pituitary tissue in vitro. Fpr1 gene deletion failed to modify the pituitary responses to dexamethasone or ANXA1(Ac2-26). However, lipoxin A4 (LXA4, 0.02-2 microM, a lipid mediator with high affinity for Fpr-rs1) mimicked the inhibitory effects of ANXA1 on ACTH release as also did fMLF in high (1-100 microM) but not lower (10-100 nM) concentrations. Additionally, a nonselective FPR antagonist (Boc1, 100 microM) overcame the effects of dexamethasone, ANXA1(1-188), ANXA1(Ac2-26), fMLF, and LXA4 on ACTH release, although at a lower concentration (50 microM), it was without effect. Together, the results suggest that the actions of ANXA1 in the pituitary gland are independent of Fpr1 but may involve other FPR family members, in particular, Fpr-rs1 or a closely related receptor. They thus provide the first evidence for a role of the FPR family in the regulation of neuroendocrine function.

Adrenocorticotropic Hormone↗
PubMed2006

National survey in the United Kingdom of prophylaxis of deep vein thrombosis for patients with fracture of the neck of the femur.

Thromboprophylaxis continues to be a contentious issue because of a lack of clear answers to pertinent questions. Hence, a survey is helpful in identifying current practices. A national survey in the UK in January 2004 investigated the use of thromboprophylaxis following fracture of the neck of the femur. Responses from 723/1648 (44%) orthopaedic consultants to a postal questionnaire showed that 623 (86%) regularly undertook trauma surgery and 625 (87%) had protocols for prophylaxis of deep venous thrombosis. In all, 555 (89%) consultants followed these protocols routinely and, of these, 276 (50%) regularly used both chemical and mechanical prophylaxis, 235 (42%) used chemoprophylaxis only and 44 (8%) used mechanical prophylaxis only. Among consultants using chemoprophylaxis, 238 (46%) used low-molecular-weight heparin, 148 (30%) used aspirin, 75 (15%) used low-molecular-weight heparin and aspirin, 35 (6%) used unfractionated heparin and 15 (3%) used warfarin. However, 68 (11%) did not use any thromboprophylaxis at all for patients with fractured neck of the femur.

Femoral Neck Fractures↗
PubMed2005

Candidemia--an under-recognized nosocomial infection in Indian hospitals.

OBJECTIVE: To study the occurrence of candidemia as a nosocomial infection in a large Indian teaching hospital and to evaluate the predisposing factors for development of such infections. METHODS: One hundred and one hospitalized patients that developed signs and symptoms of nosocomial bloodstream infections were screened for candidemia and were analyzed for the various predisposing factors like the age of the patient, the duration of hospitalization before the development of fever, neutropenia, use of chemotherapeutic agents, central venous catheters, broad spectrum antibiotics, infection with HIV, diabetes mellitus, use of corticosteroids, administration of total parenteral nutrition, haemodialysis, use of mechanical ventilation, hematological or other malignancies, underlying disease, and any surgical procedure performed on the patient. Candidemic patients were followed up for outcome and the effect of nosocomial candidemia on mortality was assessed and analyzed statistically. RESULTS: Out of the 101 patients, seven patients had candidemia, an incidence in study population of 6.9%. Three (42.8%) were infected with albicans and the rest with non-albicans candidemia. All the patients with candidemia were admitted in the Intensive Care Units. Amongst the risk factors, the length of hospitalization (p = 0.018), broad-spectrum antibiotics (p = 0.045), central venous catheters (p = 0.005), mechanical ventilation (p = 0.0139) and total parenteral nutrition (p = 0.001) were found to be significantly related to acquisition of nosocomial candidemia. Mortality in the candidemic patients was influenced only by the age of the patients (p = 0.001). Although the mortality amongst the candidemic patients was twice as much as that of the patients not having this infection, still the difference did not reach significance (p = 0.117). CONCLUSION: Candidemia is an important problem in Indian hospitals. Diagnostic delays could be shortened by more active screening for candidemia especially in the intensive care settings. The rising incidence of non-albicans candidemia in the United States probably is true here as well. There should be a concerted effort to control known risk factors especially in intensive care units.

Adolescent↗
PubMed2005

Successful pregnancy in untreated limited Wegener's granulomatosis.

A thirty four year old female presented with upper and lower respiratory symptoms in the third trimester of pregnancy. After the delivery of a healthy baby, the symptoms progressed to involve multiple organ systems and eventually a diagnosis of limited Wegener's Granulomatosis (Carrington-Liebow syndrome) was made. The extremely rare combination of WG and pregnancy, especially the onset of disease in late pregnancy is discussed. The successful outcome of pregnancy even without treatment of WG is the highlight of the case.

Adult↗
PubMed2004

Management of intracapsular femoral neck fractures in the elderly; is it time to rethink our strategy?

We reviewed 100 adult patients who had a traumatic intracapsular femoral fracture internally fixed prior to 1998, with full clinical and radiological data available. End points were complete clinical and radiological union of the fracture, non-union, avascular necrosis or fixation failure. The incidence of non-union and avascular necrosis was found to be 13 and 11%, respectively. The following factors did not influence the development of avascular necrosis or non-union; fracture displacement, screws inserted (two or three), osteoporosis, parallelism of screws, presence of screws in each "quadrant" and the experience or seniority of the surgeon. The factors influencing a poor outcome were the age of the patient at injury, reduction gap at the fracture site, alignment after reduction of the fracture especially on AP view and having all screw threads crossing beyond the fracture site. We conclude that the incidence of non-union and avascular necrosis following fixation of femoral neck fractures in our study is less than generally reported with no statistical difference between displaced and undisplaced fractures. Traditional fixation factors such as screw position and number do not seem to significantly affect the outcome with the quality of reduction being most important. Thus, the majority of patients under the age of 70 with displaced intracapsular fracture should be considered for internal fixation.

Age Factors↗
PubMed2001

Quantal density functional theory of excited states.

We explain by quantal density functional theory the physics of mapping from any bound nondegenerate excited state of Schrödinger theory to an S system of noninteracting fermions with equivalent density and energy. The S system may be in a ground or excited state. In either case, the highest occupied eigenvalue is the negative of the ionization potential. We demonstrate this physics with examples. The theory further provides a new framework for calculations of atomic excited states including multiplet structure.

Journal Article↗
PubMed2000

Reconstructing the cosmic equation of state from supernova distances.

Observations of high-redshift supernovae indicate that the Universe is accelerating. Here we present a model-independent method for estimating the form of the potential V(phi) of the scalar field driving this acceleration, and the associated equation of state w(phi). Our method is based on a versatile analytical form for the luminosity distance D(L), optimized to fit observed distances to distant supernovae and differentiated to yield V(straight phi) and w(straight phi). Our results favor w(phi) approximately -1 at the present epoch, steadily increasing with redshift. A cosmological constant is consistent with our results.

Astronomy↗
PubMed1992

The potent irritancy of the daphnane orthoester, resiniferatoxin, exhibits features of a mixed aetiology.

Resiniferatoxin-induced erythema of mouse ear was shown to possess characteristics of both a phorbol ester-mediated response and that induced by the neurogenic irritant, capsaicin. Whereas the response to the phorbol ester, sapintoxin D, was delayed and prolonged, and was augmented by capsaicin pretreatment, the response to resiniferatoxin was biphasic, with the early phase being antagonized by capsaicin desensitization. However, resiniferatoxin was most potent in inducing a delayed erythema which, unlike the capsaicin response, was sensitive to inhibition by low dose hydrocortisone treatment, but not to chronic capsaicin desensitization. It is concluded that the erythema response to resiniferatoxin has a mixed aetiology, which may explain the unique potency of this toxin.

Animals↗