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Biomedical subjects

N Jain

Publications and source records attributed to N Jain.

At least 37 records · Page 2Linked to original sources
PubMed2001

Effect of electroconvulsive therapy on hematological parameters.

Although a complete blood count is part of the evaluation before the use of electroconvulsive therapy (ECT), there are no known hematological contraindications for the procedure. A preliminary study was done on 31 randomly selected psychiatric patients (chronic schizophrenia, n=10; acute depression, n=8; acute mania, n=6; acute psychosis, n=6; delusional disorder, n=1) receiving ECT to study its hematological effects. Blood samples were drawn just before and 0, 1 and 2 h after ECT. Hemoglobin (Hb%), total and differential leukocyte count (TLC and DLC), red blood cell (RBC) count, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC) and platelet count were measured on a fully automated hematology analyzer (Sysmex K-1000). Significant changes were found in TLC, percentage of polymorphs and lymphocytes, and Hb%. Changes in other parameters were not statistically significant. More such studies are needed to substantiate these observations and to understand the mechanism and implication of these effects.

Adolescent↗
PubMed2001

Solubilization of NSC-639829.

Solubilization using pH combined with cosolvents, surfactants, and complexants are investigated for NSC-639829, an investigational anti-tumor agent. The intrinsic solubility of the drug is approximately 30 ng/ml and it has an ionizable dimethyl aniline group with an approximate base pK(a) of 5. Samples buffered at pH 1.0, 2.0, and 7.0 with various concentrations of the solubilizing agents were used to study the solubilization of NSC-629829 when present as charged and uncharged species. The solubilization of NSC-639829 was found to be much more effective when the drug was present primarily in ionized form. At pH values 1.0 and 2.0 where the surfactant (SLS) and complexant (SBEbetaCD) carried a negative charge enhanced solubilities of more than a million-fold were observed for the drug.

Antineoplastic Agents↗
PubMed2001

Modes of granular segregation in a noncircular rotating cylinder.

Axial segregation is a well-known example of segregation of granular materials. However, at present, there is no conclusive explanation as to why it occurs. Most studies of axial segregation to date are based on cylinders with circular cross sections, and models focus on the character of the surface flow without accounting explicitly for the influence of any subsurface detail. The present experiments demonstrate that the cross section of the mixer has a significant influence on axial segregation and that subsurface dynamics are, in fact, important. Unlike circular mixers, in square mixers the subsurface segregation patterns change with filling level, as does the time dependence of axial segregation. Furthermore, when radial segregation patterns in noncircular mixers most closely resemble that observed for circular cylinders, the time dependence for axial band formation deviates the most. These results challenge segregation theories of axial segregation that ignore subsurface effects.

Journal Article↗
PubMed2001

Redox-dependent conformational selection in a Cys4Fe2S2 ferredoxin.

Putidaredoxin (Pdx), a Cys4Fe2S2 ferredoxin from Pseudomonas putida, exhibits redox-dependent binding to its physiological redox partner, cytochrome P450(cam) (CYP101), with the reduced form of Pdx (Pdx(r)) binding with greater affinity to oxidized camphor-bound CYP101 than the oxidized form, Pdx(o). It has been previously shown that Pdx(o) is more dynamic than Pdx(r) on all accessible time scales, and it has been proposed that Pdx(r) samples only a fraction of the conformational substates populated by Pdx(o) on a time average. It is postulated that the ensemble subset populated by Pdx(r) is the same subset that binds CYP101, providing a mechanism for coupling the Pdx oxidation state to binding affinity for CYP101. Evidence from a variety of sources, including redox-dependent shifts of 15N and 13C resonances, indicates that the metal cluster binding loop of Pdx is the primary determinant of redox-dependent conformational selection. Patterns of paramagnetic effects suggest that the metal cluster binding loop contracts around the metal cluster upon reduction, possibly due to the strengthening of hydrogen bonds between the sulfur atoms of the metal cluster and the surrounding polypeptide NH and OH groups. Effects of this perturbation are then transmitted mechanically to other affected regions of the protein. A specific mutation has been introduced into the metal binding loop of Pdx, G40N, that slows conformational exchange sufficiently that the ensemble of conformational substates in Pdx(o) are directly observable as severe broadenings or splittings in affected NMR resonances. Many of the residues most affected by the mutation also show significant exchange contributions to 15N T(2) relaxation in wild-type Pdx(o). As predicted, G40N Pdx(r) shows a collapse of many of these multiplets and broadened lines to form much sharper resonances that are essentially identical to those observed in wild-type Pdx(r), indicating that Pdx(r) occupies fewer conformational substates than does Pdx(o). This is the first direct observation of such redox-dependent ensembles at slow exchange on the chemical shift time scale. These results confirm that conformational selection within the Fe2S2 cluster binding loop is the primary source of redox-dependent changes in protein dynamics in Pdx.

Amino Acid Sequence↗
PubMed2001

Self-organization in granular slurries.

We report the existence of self-organization in wet granular media or slurries, mixtures of particles of different sizes dispersed in a lower density liquid. As in the case of dry granular mixtures, axial banding (alternating bands rich in small and large particles in a long rotating cylinder) and radial segregation (in quasi-2D containers) are observed in slurries. However, when compared with the dry counterpart axial segregation is significantly faster and the spectrum of outcomes is richer. Moreover, experiments with suitable fluids reveal, for the first time, the internal structure of axially segregated systems, something that up to now has been accessible only via magnetic resonance imaging experimentation.

Journal Article↗
PubMed2001

Anatomic correlates of the face and oral cavity representations in the somatosensory cortical area 3b of monkeys.

We determined the somatotopy of the face and the oral cavity representation in cortical area 3b of New World owl monkeys and squirrel monkeys. Area 3b is apparent as a densely myelinated strip in brain sections cut parallel to the surface of flattened cortex. A narrow myelin-light septum that we have termed the "hand-face septum" separates the hand representation from the more lateral face and mouth representation. The face and oral cavity representation is further divided into a series of myelin-dense ovals. We show that three ovals adjacent to the hand representation correspond to the upper face, upper lip, and chin plus lower lip, whereas three or four more rostral ovals successively represent the contralateral teeth, tongue, and the ipsilateral teeth and tongue. Strips of cortex lateral and medial to the area 3b ovals, possibly corresponding to area 1 and area 3a, respectively, have similar somatotopic sequences. Although previous results suggest the existence of great variability within and across primate species, we conclude that the representations of the face and mouth are highly similar across individuals of the same species, and there are extensive overall similarities across these two species of New World monkeys.

Animals↗
PubMed2001

Estimation of the aqueous solubility I: application to organic nonelectrolytes.

The estimation of aqueous solubilities of organic nonelectrolytes by the General Solubility Equation (GSE) as proposed by Valvani and Yalkowsky (1980) is used in this study. The data and assumptions on which the GSE are based are reevaluated, and the equation is revised. The revised GSE is validated on a set of 580 pharmaceutically, environmentally, and industrially relevant nonelectrolytes. The revised equation has a stronger theoretical background and provides a more accurate estimation of aqueous solubility.

Organic Chemicals↗
PubMed2001

Haemolytic disease of newborn.

Hemolytic disease of the newborn (HDN) occurs due to maternal IgG antibodies crossing the placenta thereby producing hemolysis mainly due to Rh, ABO and Kell groups. A systematic approach to the Rh HDN involves an obstetric history of previous isoimmunized baby, timing and regular monitoring of maternal Rh antibodies and pigment assay of amniotic fluid. Timely decision regarding in utero transfusion and early termination of pregnancy based on the maternal monitoring has radically improved the outcome of these babies. Antenatal prophylaxis with anti D has resulted in great reduction in the magnitude of Rh problem. The fetal blood sampling and in-utero intravenous transfusions has made it possible for almost 100% survival of isoimmunized pregnancies without hydrops. Alternative methods--IVIG and plasma exchange are still of limited application. ABO HDN though common is not a serious form of disease and dose not warrants invasive antenatal monitoring. Anti-Kell is found in patients having received multiple transfusions and the rapid progress of hemolysis in them may not allow such systematic follow up as in Rh HDN.

Algorithms↗
PubMed2001

Upper respiratory tract infections.

Acute respiratory infections accounts for 20-40% of outpatient and 12-35% of inpatient attendance in a general hospital. Upper respiratory tract infections including nasopharyngitis, pharyngitis, tonsillitis and otitis media constitute 87.5% of the total episodes of respiratory infections. The vast majority of acute upper respiratory tract infections are caused by viruses. Common cold is caused by viruses in most circumstances and does not require antimicrobial agent unless it is complicated by acute otitis media with effusion, tonsillitis, sinusitis, and lower respiratory tract infection. Sinusitis is commonly associated with common cold. Most instances of rhinosinusitis are viral and therefore, resolve spontaneously without antimicrobial therapy. The most common bacterial agents causing sinusitis are S. pneumoniae, H. influenzae, M. catarrhalis, S. aureus and S. pyogenes. Amoxycillin is antibacterial of choice. The alternative drugs are cefaclor or cephalexin. The latter becomes first line if sinusitis is recurrent or chronic. Acute pharyngitis is commonly caused by viruses and does not need antibiotics. About 15% of the episodes may be due to Group A beta hemolytic streptococcus (GABS). Early initiation of antibiotics in pharyngitis due to GABS can prevent complications such as acute rheumatic fever. The drug of choice is penicillin for 10-14 days. The alternative medications include oral cephalosporins (cefaclor, cephalexin), amoxicillin or macrolides.

Anti-Bacterial Agents↗
PubMed2001

Tassier cleft no 30 (median cleft from lower lip to manubrium).

One-year-old female presented with cleft of lower lip, mandible, fissured tongue, absent hyoid bone, cleft of manubrium sterni, later is detected clinically by suprasternal bulge at suprasternal region while crying. It is radiologically detected by wide apart medial end of clavicle. This is extremely rare anomaly known as Tassier Cleft no 30.

Abnormalities, Multiple↗
PubMed2001

Biosorption of chromium(VI) from aqueous solutions by green algae Spirogyra species.

Biosorption of heavy metals is an effective technology for the treatment of industrial wastewaters. Results are presented showing the sorption of Cr(VI) from solutions by biomass of filamentous algae Spirogyra species. Batch experiments were conducted to determine the adsorption properties of the biomass and it was observed that the adsorption capacity of the biomass strongly depends on equilibrium pH. Equilibrium isotherms were also obtained and maximum removal of Cr(VI) was around 14.7 x 10(3) mg metal, kg of dry weight biomass at a pH of 2.0 in 120 min with 5 mg/l of initial concentration. The results indicated that the biomass of Spirogyra species is suitable for the development of efficient biosorbent for the removal and recovery of Cr(VI) from wastewater.

Adsorption↗
PubMed2001

Enhanced anti-cancer activities of some derivatives of titanocene dichloride.

The compounds (eta5-C5H5)2TiCl2 (I), currently undergoing phase II trials, (eta5-C5H5)(eta5-C5H4CO2Me)TiCl2 (II) and C5H4CO2Me)2TiCl2 (III) are assessed for their efficacies against a small lung cancer cell line. It is found that the introduction of the electron withdrawing carbomethoxy group into the cyclopentadienyl rings increases the effectiveness of this class of drugs, such that III compares favorably with the well known cisplatin.

Antineoplastic Agents↗
PubMed2001

Effects of light intensity, n-alcohols, water-soluble colorants, and solution viscosity on photoisomerization of sorivudine.

Effects of various factors, such as light intensity, polarizability of n-alcohol solvents, addition of colorants, and viscosity of solutions on the kinetics of the photoisomerization of therapeutically effective E-isomer of sorivudine to its less effective Z-isomer were studied. Solutions of known concentrations of E-isomer or Z-isomer in water or in a series of n-alcohols were directly exposed to ultraviolet (UV) A light, or visible light of 400 or 900 foot candles (fc). E-isomer solutions containing various colorants at 1% w/v, or in a series of poloxamer solutions of different viscosities, were also exposed to 400 or 900 fc light. Using the stability-indicating HPLC assay, which showed mass-balance between the starting isomer and the converting isomer, the kinetics of photoisomerization were monitored. The photoisomerization reaction, which takes place on the vinyl side chain, was found to be a first-order reversible reaction. In water, the rate of conversion of E-isomer to Z-isomer was faster than that of Z-isomer to E-isomer, since, E-isomer with higher extinction coefficient absorbed substantially more light than Z-isomer. The rate of photoisomerization increased with the intensity of the visible light and was very rapid in the presence of UV A light (300 to 400 nm), which is to be expected based on the 239 nm and 283 nm absorption maxima of sorivudine. Addition of water-soluble colorants retarded the photoisomerization process significantly, especially as the maximum absorption wavelengths (lambda max) of the colorants approached the UV region. The rate of photoisomerization increased with increasing polarizability (alpha s) of the n-alcohol solvents. Polarizable solvents such as alcohols could compensate for the electron density built up in the excited state, and thus facilitated the photoisomerization process. The rate of photoisomerization decreased as the viscosity of solution increased. This may be attributed to the fact that the twisting of the C=C bond in the excited state can be inhibited by the friction imposed by the viscous medium.

Alcohols↗
PubMed2001

Barriers to acceptance: an exploratory study of complementary/alternative medicine disuse.

BACKGROUND: Previous research indicates wide use of complementary and alternative medicine (CAM). While understanding this trend is certainly important, an equally meaningful although largely unexamined research question is: why do the majority of patients and individuals fail to avail themselves of such therapies? Understanding these factors may be particularly important given the increasing evidence suggesting that certain of these therapies may be efficacious. METHODS: A two-page survey that examined demographic characteristics, attitudes toward CAM, and rates of use of specific CAM therapies was mailed to a randomly selected sample of 1680 Stanford University alumni. A total of 601 responses were received (response rate, 35.8%). Multiple regression analyses were carried out to examine predictors of general CAM disuse and disuse of specific therapies. RESULTS: The following variables predicted disuse of CAM in general (p < 0.05): (1) being male (odds ratio [OR] 0.65; 95% confidence interval [CI] 0.44-0.98); (2) being healthy (OR 0.95; 95% CI 0.91-0.99); (3) lack of physician support for CAM use (OR 1.82; 95% CI 1.42-2.29); and (4) believing CAM treatments are ineffective or inferior (OR 0.27; 95% CI 0.19-0.38). Lack of knowledge about CAM approached significance (p = 0.068). With regards to specific therapies, the following patterns were seen: disuse of massage was associated with being male and younger; lack of physician support predicted disuse for all treatments except acupuncture and homeopathy; the belief that CAM treatments in general are ineffective predicted disuse of all therapies except chiropractic while the belief that chiropractic was ineffective predicted its disuse; the perception that CAM produced negative side-effects predicted disuse of chiropractic; lack of knowledge of CAM predicted disuse of herbs, chiropractic, and homeopathy; positive health status was associated with disuse of chiropractic; and finally, the perception that providers were not in accessible locations predicted disuse of all CAM therapies except homeopathy and meditation. CONCLUSIONS: Study findings indicate people are less likely to use CAM if they are male, are in good health, believe that the therapies are in general ineffective or inferior to conventional methods, perceive that conventional medical doctors are not supportive, and to a lesser extent feel they do not have adequate knowledge of CAM. Specifically, avoidance of chiropractic is associated with concerns for safety and side-effects. For treatments that are more provider-based as opposed to self-care based, lack of accessibility-to providers may explain disuse. As researchers continue to demonstrate the clinical efficacy of CAM therapies, these preliminary findings deserve attention because they highlight potential reasons why patients and physicians may be biased against or unable to avail themselves of such therapies.

Adult↗
PubMed2001

Clinical characteristics of familial B-CLL in the National Cancer Institute Familial Registry.

In an ongoing study, families with two or more living cases of B-CLL in first-degree relatives have been recruited through physician and self-referral. Since 1967, 28 kindreds with 73 cases of B-CLL have been enrolled within the National Cancer Institute (NCI) Familial B-CLL Registry. Medical, clinical, and demographic information have been obtained from private physicians, patient interview, hospital records, and death certificates. We used SEER Registry data to compare characteristics of sporadic B-CLL to familial B-CLL. The mean age at diagnosis was approximately 10 years younger among familial cases (57.9 +/- 12.1) than that observed in sporadic cases (70.1 +/- 11.9). A higher percentage of second primary tumors among familial CLL cases compared to reports in sporadic was also observed (16% vs. 8.8%). However, the transformation rate to non-Hodgkin's lymphoma does not appear to be different from that reported for sporadic cases. In conclusion, we observed some differences between familial and sporadic cases; whether any of these characteristics affect survival time or severity of disease is unknown. The study of families with multiple B-CLL cases will aid in delineating the genes and environmental factors that may play a role in the development of both forms of B-CLL.

Age of Onset↗