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Biomedical subjects

V Singh

Publications and source records attributed to V Singh.

At least 91 records · Page 5Linked to original sources
PubMed2001

Evaluation of the role of facet joints in persistent low back pain in obesity: a controlled, prospective, comparative evaluation.

Chronic low back pain and obesity are two common medical conditions. Obesity has been associated with symptoms such as adverse fat distribution and multiple secondary disorders, including low back pain. Obesity is defined as being 30% over ideal weight, which influences normal body mechanics as well as recovery from an injury. Facet joints have been described as contributing to a significant proportion of patients suffering with persistent or chronic low back pain, variably from 15% to 45%. Since an obese patient is at a higher risk of disability compared to a patient with normal weight, obesity has been described as a confounding factor in persistent low back pain. This study included 100 patients, with 50 patients in Group I who were of normal weight and 50 patients in group II who were obese, by random allocation. Facet joints were investigated with diagnostic blocks using lidocaine 1% initially, followed by bupivacaine 0.25%. The results showed that the prevalence rate of facet joint pain in chronic low back pain in Group I or nonobese patients was 36%, in contrast to 40% in Group II, or the obese patient group, with no significant differences among the two groups. The study also showed a false-positive rate of 39% in the total sample, or 44% in Group I nonobese patients and 33% in Group II, or obese patients. It is concluded that the prevalence of lumbar facet joint mediated pain of 40% in obese patients and 36% in patients of normal weight with a false-positive rate of 33% in obese patients and 44% in nonobese patients is similar to the results of multiple previous studies concluding that facet joint mediated pain is a common occurrence in obese patients; however, the incidence of facet joint mediated pain is similar in obese patients and nonobese patients.

Journal Article↗
PubMed2001

Evaluation of the relative contributions of various structures in chronic low back pain.

An attempt was made to determine the relative contribution of various structures to chronic low back pain, including facet joint(s), disc(s), and sacroiliac joint(s) in a prospective evaluation. Precision diagnostic blocks, including disc injections, facet joint blocks, and sacroiliac joint injections, are frequently used. In contrast, selective nerve root blocks or transforaminal epidural injections are used occasionally to evaluate persistent or recurrent low back pain in patients without appropriate radiologic or neurophysiologic diagnosis. One hundred and twenty patients with a chief complaint of low back pain were evaluated with precision diagnostic injections, which included medial branch blocks, provocative discography and sacroiliac joint injections. In 40% (95% CL, 31%, 49%), of the patients, facet joint pain was diagnosed; and in 26% (95% CL, 18%, 34%) of the patients discogenic pain was diagnosed; and 2% of the patients were diagnosed with sacroiliac joint pain.

Journal Article↗
PubMed2001

The role of guidelines in interventional pain medicine: let us separate apples and oranges.

Practice guidelines are not only an ancient tradition, but they are a fact of life. The first guidelines were developed in the 1840s, shortly after the use of anesthesia was first demonstrated. Even though practice guideline development has spawned an impressive and over-aggressive literature of its own, many unanswered questions exist with regard not only to practice parameters and guidelines in general, but in particular with the application of interventional techniques in managing persistent pain. In spite of the great potential of clinical practice guidelines, and the involvement of numerous medical societies and physician groups, there is still a great debate within the profession not only about the pros and cons of the development and usage of the guidelines, but also conflicting and controversial opinions on both sides of the issue, i.e., providers and patients vs payors. This article discusses the development, usage, advantages, disadvantages and the implications of practice guidelines to interventional pain medicine specialists.

Journal Article↗
PubMed2001

Interventional techniques in the management of chronic pain: Part 2.0.

The practice guidelines for interventional techniques in the management of chronic pain are systematically developed statements to assist physician and patient decisions about appropriate health care related to chronic pain. These guidelines are professionally derived recommendations for practices in the diagnosis and treatment of chronic or persistent pain. They were developed utilizing a combination of evidence and consensus based techniques, to increase patient access to treatment, improve outcomes and appropriateness of care, and optimize cost-effectiveness. The guidelines include a discussion of their purpose, rationale, and importance, including the patient population served, the methodology and the pathophysiologic basis for intervention. Various interventional techniques will be discussed addressing the rationale for their use in chronic pain with analysis of the outcomes data and cost effectiveness. These guidelines do not constitute inflexible treatment recommendations. It is expected that a provider will establish a plan of care on a case-by-case basis, taking into account an individual patient's medical condition, personal needs, and preferences, and the physician's experience. Based on an individual patient's needs, treatment different from that outlined here could be warranted.

Journal Article↗
PubMed2000

Structural diversity through intramolecular cycloaddition and modulation of chemical reactivity in excited state. Synthesis and photoreactions of 3-oxa-tricyclo[5.2.2.0(1,5)]undecenones: novel stereoselective route to oxa-triquinanes and oxa-sterpuranes.

Synthesis of 11-methyl-3-oxa-tricyclo[5.2.2.0(1,5)]undecenones by intramolecular Diels-Alder reaction of highly labile spiroepoxycyclohexa-2,4-dienones and its photochemical reactions upon triplet (3T) and singlet (1S) excitation leading to a stereoselective route to oxa-triquinane and oxa-sterpurane, respectively, is described.

Heterocyclic Compounds↗
PubMed2000

Chronic therapy with metoprolol attenuates cardiomyocyte apoptosis in dogs with heart failure.

OBJECTIVES: The purpose of this study was to determine if therapy with beta-blockade is associated with reduced cardiomyocyte apoptosis. BACKGROUND: Chronic treatment with beta-adrenergic blocking agents has been shown to improve left ventricular (LV) ejection fraction and attenuate progressive LV remodeling in heart failure (HF). Cardiomyocyte apoptosis has also been shown to occur in the failing heart. METHODS: Moderate HF was produced in 14 dogs by intracoronary microembolizations. Dogs were randomized to three months therapy with metoprolol (MET, 25 mg twice daily, n = 7) or to no therapy at all (n = 7). At the end of three months, dogs were sacrificed, and nuclear DNA fragmentation (nDNAf), a marker of apoptosis, was assessed in LV tissue using the TUNEL assay. The number of cardiomyocytes with positive nDNAf labeling per 1,000 was quantified in LV regions bordering old infarcts and in regions remote from infarcts. Endonuclease activity and expression of the antiapoptotic protein Bcl-2 and the proapoptotic proteins Bax and caspase-3 were also evaluated in LV tissue. RESULTS: The number of nDNAf events per 1,000 cardiomyocytes was lower in dogs treated with MET compared with untreated dogs with HF in the border regions (0.35 +/- 0.07 vs. 5.32 +/- 0.77, p < 0.001) as well as the remote regions (0.07 +/- 0.05 vs. 0.39 +/- 0.12, p < 0.05). Endonuclease activity was also significantly lower in MET-treated compared with untreated dogs (25 +/- 3 vs. 37 +/- 2 ng [3H]DNA rendered soluble/min/mg protein). Western blotting for Bcl-2, Bax and caspase-3 showed increased expression of Bcl-2, decreased expression of caspase-3 and no change in Bax in MET-treated compared with untreated dogs. CONCLUSIONS: Chronic therapy with MET attenuates cardiomyocyte apoptosis in dogs with moderate HF. Attenuation of ongoing cardiomyocyte loss through apoptosis may be one mechanism through which beta-blockers elicit their benefits in HF.

Adrenergic beta-Antagonists↗
PubMed2000

Disulfide bond formation is not required for human chorionic gonadotropin subunit association. Studies with dithiothreitol in JEG-3 cells.

To study the influence of disulfide bridge formation on the assembly of the subunits of human chorionic gonadotropin in JEG-3 choriocarcinoma cells, dithiothreitol (DTT) was used to create a reducing milieu in the endoplasmic reticulum (ER) in vivo. In the presence of 5 mM DTT during pulse-chase experiments all of the beta-subunit precursors observed in unperturbed cells (pbeta(0), pbeta(1), pbeta(2), and beta(*)) collapsed into the pbeta(0) form. The reducing milieu of the ER was reoxidized in less than 5 min after removal of DTT from the medium. DTT markedly increased the half-life of the pbeta(0) precursor from 8.8 to 65.2 min. Under reoxidation conditions, the beta-subunit precursors folded back from pbeta(0) in less than 5 min. In unperturbed JEG-3 cells, the alpha-subunit was present in both fully glycosylated and monoglycosylated precursor (pre-alpha) forms. The attachment of the second N-linked glycan residue of the alpha-subunit was accelerated in the presence of DTT, and consequently pre-alpha-subunit was missing from the DTT-treated cultures. The formation of alphabeta-dimers appeared to be at least partially independent of the oxidation state in the ER. The alphabeta-dimer was present under conditions in which disulfide bridge formation was prevented by exposure to 5 mM DTT before and during the pulse period. This clearly suggests that the human chorionic gonadotropin subunits may acquire association-competent conformations even when no disulfide bridge formation has taken place.

Chorionic Gonadotropin, beta Subunit, Human↗
PubMed2000

Vegetative survival, akinete formation and germination in three blue-green algae and one green alga in relation to light intensity, temperature, heat shock and UV exposure.

The mere vegetative survival was not sufficient but suitable growth conditions were required for akinete formation to occur in the blue-green algae Anabaena iyengarii, Westiellopsis prolifica, Nostochopsis lobatus and in the green alga Pithophora oedogonia. In all algae, akinetes were neither formed nor germinated in darkness, and while dim light of 300 lx was sufficient for most of akinetes to germinate and also to maintain vegetative survival, it was not adequate for optimum akinete formation. Although akinetes of all algae could germinate at 35 degrees C, both the vegetative survival and akinete formation were markedly suppressed at this temperature. Heat or UV shock of any level, whether ineffective or effecting vegetative survival, did not promote akinete formation or germination in any alga tested. Akinetes of all algae under study were relatively tolerant to heat and also to some extent to UV. Both wet and dried akinetes of all algae were equally UV tolerant. In all algae, the viability of both wet and dried akinetes decreased more or less equally with storage time, but the decrease was more drastic when storage temperature was progressively lowered from 20 to 0 degree C. Hence the akinetes can tolerate dryness but not frost.

Chlorophyta↗
PubMed2000

Variations in the pattern of mental spines and spinous mental foramina in dry adult human mandibles.

The frequency and morphology of mental spines and spinous mental foramina was studied in 1200 adult human mandibles of Indian origin. The mental spines were present in 1178 mandibles (98.2%). The usual textbook description of four spines, arranged in two pairs one above the other was found only in 231 mandibles (19.6%). Mandibles with only two superior mental spines were seen in 842 cases (71.4%) which were associated with either a median vertical ridge below them (47.7%) or with a rough impression in place of the median ridge (23.7%). Spinous mental foramina (one to three) close to the midline and in between the spines were found in 1165 mandibles (97.57%). The presence of these foramina has not been mentioned in most textbooks of anatomy.

Adult↗
PubMed2000

A new secoiridoid glycoside from Lonicera angustifolia.

A new secoiridoid glycoside, 6'-O-beta-apiofuranosylsweroside (1), together with the known compounds sweroside, loganin, beta-sitosterol, oleanolic acid, ursolic acid and methyl-4-hydroxy benzoate have been identified from the leaves of Lonicera angustifolia. The structure of the new compound has been elucidated on the basis of spectroscopic and chemical evidence.

Glucosides↗
PubMed2000

Thermal and physicochemical properties of rice grain, flour and starch.

Three types of rices, namely, Thailand rice (Indica), Nipponbare (Japonica), and Himenomochi (Japonica waxy), in grain, flour, and starch forms have been studied for their thermal and physicochemical properties. In grain form, Indica was slender and Japonica rices were bold and thick. Indica had the highest protein and amylose equivalent. Protein contents in isolated starches varied from 0.2 to 0.9%. Cooked Indica grain was hardest and waxy rice was softest; stickiness was highest in Japonica rice. Glass transition temperature (T(g)) was highest in Indica rice flour (approximately 222 degrees C) and almost the same in Japonica rice flours. Melting point was highest for Japonica (approximately 264 degrees C) and almost the same for Japonica waxy and Indica rice flours. T(g) values of starches were almost the same in Indica and Japonica waxy (approximately 237 degrees C); defatting caused reduction in this property in all of the starches. Highest melting point was shown by Indica starch (approximately 276 degrees C) and was almost the same for the other two starches. Protein and fats play a critical role in glass transition and melting points of rice flours and their respective starches. Viscosities of the cooked pastes of flour and starch during cooking in an RVA instrument and their gel and other properties have been discussed.

Calorimetry, Differential Scanning↗
PubMed2000

Determination of iodide by derivatization to 4-iodo-N,N-dimethylaniline and gas chromatography-mass spectrometry.

A real-time determination of iodide is proposed which involves the oxidation of iodide with 2-iodosobenzoate in the presence of N,N-dimethylaniline. The reaction is completed within 1 min to yield 4-iodo-N,N-dimethylaniline, which is extracted in cyclohexane and determined by GC-MS. It was also possible to determine iodine by derivatization in the absence of 2-iodosobenzoate, and iodate by its reduction with ascorbic acid to iodide and subsequent derivatization. A rectilinear calibration graph was obtained for 0.02-50 micrograms l-1 iodide with a correlation coefficient of 0.9998. The limit of detection was 8 ng l-1 iodide. The method was applied to the determination of iodate in iodized table salt and free iodide and total iodine in sea-water, and to spiked samples when the recovery was in the range 96.8-104.3% (RSD 1.9-3.6%). A sample clean-up by solid-phase extraction with a LiChrolut EN cartridge is proposed.

Gas Chromatography-Mass Spectrometry↗
PubMed2000

Budd-Chiari syndrome: our experience of 71 patients.

BACKGROUND: Hepatic venous outflow obstruction (Budd-Chiari syndrome) is frequently encountered as a cause of portal hypertension at our centre. METHODS AND RESULTS: We studied the clinical presentation, therapeutic modalities and outcome of 71 patients with hepatic venous outflow obstruction between 1992 and 1997. Twenty-seven patients presented with acute disease, while 44 had chronic presentation. Abdominal pain, distension, jaundice and upper gastrointestinal bleeding were the commonest presenting symptoms. The majority of patients had distended veins, hepatomegaly, splenomegaly, ascites and ankle oedema. The diagnosis was made on the basis of inferior vena cavography/functional hepatography and pulsed Doppler ultrasonography and/or liver biopsy in 39 patients and pulsed Doppler ultrasonography and/or liver biopsy in 32 patients. Pulsed Doppler ultrasonography accurately detected the site of the block in 31 of 39 patients (79.4%). The obstruction was in the hepatic vein in 20 patients, in the inferior vena cava in 10, and in both in 41 patients. Aetiologically, four had pregnancy-related disease, four tumour-related, three hypercoagulable states, 18 inferior vena cava membranes and 42 were idiopathic. Of 30 patients in whom liver biopsy was carried out, eight had centrizonal congestion and necrosis, 13 had mixed features and nine had established cirrhosis. Seven patients underwent a shunt operation and surgical membranotomy was carried out in one. Three patients (4.2%) died in the hospital. CONCLUSIONS: Hepatic venous outflow obstruction is a common problem; patients present with abdominal pain, distension, jaundice, distended veins, ascites and ankle oedema. Chronic presentation is more frequent. Pulsed Doppler ultrasound, venography and liver biopsy are very helpful in diagnosis.

Adolescent↗
PubMed2000

Superoxide anion formation and glutathione levels in patients with preeclampsia.

Increased free radical activity has been implicated in the pathogenesis of preeclampsia. This article investigates the glutathione status in preeclampsia and whether superoxide generation is enhanced in preeclampsia. Venous blood samples were obtained from 30 preeclamptic women and 30 normotensive pregnant women (controls). Superoxide generation and glutathione content were measured. There was a significant increase in superoxide generation and a marked reduction in glutathione content in preeclamptic women as compared to controls (p < 0.001). These results indicate that enhanced superoxide generation and impaired glutathione metabolism may be involved in the pathogenesis of preeclampsia.

Adolescent↗
PubMed2000

Influence of soybean trypsin inhibitor on small bowel enzyme activities during rotavirus infection in malnourished infant mice.

Rotavirus (RV) is considered to be one of the major causes of acute episodic diarrhoea throughout the world. This study was undertaken to investigate the effect of soybean trypsin inhibitor (TI) on brush-border enzymes during rotavirus infection in protein energy malnourished (PEM) infant mice. Animals were divided into 4 groups, namely controls, PEM, PEM+RV and PEM+RV+TI (n = 36 each). Group 1 and 2 animals were orally inoculated with 50 microl of normal saline each. Group 3 animals were orally inoculated with 50 microl of 100 ID50 dose of RV stock each. Group 4 animals were similarly inoculated with 0.6 mg TI/g body weight along with 50 microl of RV stock each. Animals were examined daily for diarrhoea and their body weight was recorded on alternate days postinoculation (dpi). Animals were killed by cervical dislocation after being given light chloroform anesthesia on 0, 1, 3, 5, 7 and 10 dpi. Small intestines were excised and homogenized in normal saline. Proteins, gammaglutamyl transpeptidase, alkaline phosphatase and disaccharidases were estimated in jejunum and ileum. Body weight was significantly reduced in PEM animals and with RV infection. Histologically, focal areas of vacuolar degeneration of lining epithelium were seen in RV-infected animals. Disaccharidases and other enzyme activities were decreased significantly in the PEM group compared to healthy controls and further depressed with RV infection in malnourished animals as compared to non-infected PEM. The enzyme activities were restored in animals receiving TI along with RV compared to the group receiving RV without TI. With the administration of soybean TI, the activities of disaccharidases, alkaline phosphatase, gammaglutamyl transpeptidase and intestinal architecture were restored showing a protective effect in PEM during RV infection.

Animals↗
PubMed2000

Study of the prevalence of asthma in adults in North India using a standardized field questionnaire.

Prevalence of asthma was calculated using a Hindi adaptation of the International Union Against Tuberculosis and Lung Disease (IUATLD)-1984 questionnaire. The questionnaire was administered to patients with and without asthma to select specific items to define asthma. Questionnaire validity was tested against physician-diagnosed asthma in 753 individuals in the field, with sensitivity and specificity of 63.1% and 98.8%, respectively. The field prevalence study was conducted among 958 men and 1158 women. True population prevalence, calculated from the observed prevalence using specificity and sensitivity of the questionnaire, was 3.94% in urban men, 3.99% in rural men, and 1.27% in both urban and rural women.

Adolescent↗
PubMed2000

Current status of ribosome inactivating proteins.

Ribosome inactivating proteins (RIPs) are a group of naturally occurring plant proteins with a RNA-N-glycosidases activity which depurinate rRNA at a specific universally conserved position (i.e. cleavage of N-glycosidic bond of a specific adenine of 28S rRNA). These proteins are found in different parts of plants, in concentrations ranging from a few micrograms to several hundred mg per 100 g of plant tissues. RIPs exist in two forms, type 1 having a single polypeptide chain with a molecular mass of approximately 30 kDa possessing N-glycosidase activity; and type 2 with two or four polypeptide chains having a molecular mass of approximately 60 kDa and approximately 120 kDa respectively showing lectin activity along with N-glycosidase moiety. Such biomolecules causing cytotoxicity are being exploited for designing immunotoxins/hormonotoxins using heterobifunctional conjugates. These carrier conjugates with the RIPs can influence cellular trafficking and inhibition of protein synthesis. We are witnessing a novel protein from plants that can be utilised for various therapeutical treatments ranging from cancers, AIDS and other viral diseases of present times.

Plant Proteins↗