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Biomedical subjects

S Aggarwal

Publications and source records attributed to S Aggarwal.

At least 19 recordsLinked to original sources

Bovine tuberculosis in India: potential basis for zoonosis.

Our laboratory has designed a specific nested-PCR (N-PCR) assay, based on the hupB gene of Mycobacterium tuberculosis (Rv2986c) and Mycobacterium bovis (Mb3010c) as a method to differentiate these closely related species. The present paper deciphers the utility of this assay for identification of pathogenic Mycobacteria in clinical samples. Extra-pulmonary clinical samples obtained from cattle and humans were investigated. Pre-dominance of M. tuberculosis (15.7%) and M. bovis (26.8%) was seen in humans and cattle, respectively. However, more importantly, both mycobacterial pathogens (mixed infection) were identified in a number of samples. In humans 8.7% of the samples and 35.7% in cattle were classified as mixed infection. The detection of mixed infection with the mycobacterial pathogenic duo in humans and bovines denotes the prospect of potential transmission of these pathogens from humans to cattle (zoonosis) and vice versa (reverse zoonosis).

Animals↗

Comminuted refracture of the distal femur and condyles in patients with an intramedullary nail: a report of 5 cases.

Patients with in situ intramedullary nails sustaining a second distal femoral fracture following high-velocity trauma are infrequently reported in the literature. We report 5 such patients who sustained a second injury after 6 to 24 months, resulting in another fracture at the nail-tip level. These second fractures severely comminuted the femoral condyles. These patients required removal of the intramedullary nail, reconstruction of the comminuted femoral condyles, and stabilisation using an angled or buttress plate. Four of the 5 patients were followed up for a mean period of 36 months and were evaluated for knee status and outcome using Judet's criteria. Postoperative knee stiffness was common, and further interventions such as manipulation, hardware removal, arthrolysis, and quadricepsplasty were needed. One patient was lost to follow-up. The final results of the knees were good, with more than 100 degrees range of movement. It is important to adhere to established internal fixation protocols in the treatment of these complex nail tip fractures.

Accidents, Traffic↗

Early versus delayed laparoscopic cholecystectomy for acute cholecystitis: a prospective randomized trial.

BACKGROUND: The role of laparoscopic cholecystectomy for acute cholecystitis is not yet clearly established. The aim of this prospective randomized study was to evaluate the safety and feasibility of laparoscopic cholecystectomy for acute cholecystitis and to compare the results with delayed cholecystectomy. METHODS: Between January 2001 and November 2002, 40 patients with a diagnosis of acute cholecystitis were assigned randomly to early laparoscopic cholecystectomy within 24 h of admission (early group, n = 20) or to initial conservative treatment followed by delayed laparoscopic cholecystectomy, 6 to 12 weeks later (delayed group, n = 20). RESULTS: There was no significant difference in the conversion rates (early, 25% vs delayed, 25%), operating times (early, 104 min vs delayed, 93 min), postoperative analgesia requirements (early, 5.3 days vs delayed, 4.8 days), or postoperative complications (early, 15% vs delayed, 20%). However, the early group had significantly more blood loss (228 vs 114 ml) and shorter hospital stay (4.1 vs 10.1 days). CONCLUSIONS: Early laparoscopic cholecystectomy for acute cholecystitis is safe and feasible, offering the additional benefit of a shorter hospital stay. It should be offered to patients with acute cholecystitis, provided the surgery is performed within 72 to 96 h of the onset of symptoms.

Acute Disease↗

Urinary leukotriene E4 and 9 alpha, 11 beta-prostaglandin F concentrations in mild, moderate and severe asthma, and in healthy subjects.

BACKGROUND: Airway inflammation in asthma is associated with cysteinyl leukotriene and prostaglandin D(2) production. Measurement of urinary metabolites of these eicosanoids may be useful for monitoring asthma patients. However, the influence of asthma phenotype and severity on basal urinary excretion of these metabolites is unknown. OBJECTIVE: To compare urinary leukotriene (LT)E(4) and 9 alpha, 11 beta-prostaglandin (PG)F(2) concentrations in large groups of mild, moderate and severe asthmatic patients and healthy control subjects. METHODS: Asthma severity, treatment and aspirin sensitivity were assessed by questionnaire in 168 asthmatic patients. Basal LTE(4) and 9 alpha, 11 beta-PGF(2) concentrations were measured in urine samples from these patients and from 175 control subjects using enzyme immunoassays. RESULTS: Urinary LTE(4) was correlated with 9 alpha, 11 beta-PGF(2) in both control subjects and asthmatic patients (P<0.002). Median LTE(4) and 9 alpha, 11 beta-PGF(2) concentrations in patients with severe asthma were significantly reduced compared with mild asthmatic patients (P<0.05 and <0.001, respectively). Urinary 9 alpha, 11 beta-PGF(2), but not LTE(4) was lower in asthmatic patients using inhaled corticosteroids (P<0.02). Multiple regression analysis indicated that urinary 9 alpha, 11 beta-PGF(2) concentration was negatively correlated with asthma severity (P=0.003) and also with % predicted FEV(1) (forced expiratory volume in 1 s) (P=0.005). CONCLUSIONS: Baseline urinary LTE(4) and 9 alpha, 11 beta-PGF(2) concentrations are of limited value in discriminating between patients with different severities of asthma. Reduced urinary LTE(4) and 9 alpha, 11 beta-PGF(2) in patients with severe asthma suggest that direct or indirect effects of high-dose corticosteroid therapy combined with other factors associated with severe asthma may influence eicosanoid production. However, the negative association of urinary 9 alpha, 11 beta-PGF(2) with lung function suggests an adverse effect of chronic PGD(2) production on lung function in asthma, irrespective of severity.

Adult↗

Concentration of a potent calcium oxalate monohydrate crystal growth inhibitor in the urine of normal persons and kidney stone patients by ELISA-based assay system employing monoclonal antibodies.

Standardized calcium oxalate monohydrate (COM) crystal growth assay system was employed to study the ability of various test samples to influence growth rates of COM crystals. The inhibitory activity (IA) of various samples was expressed in terms of inhibitory units. Urine samples obtained from normal persons and kidney stone patients were found to have IA of 3.18 +/- 0.62 and 1.02 +/- 0.08, respectively. A potent inhibitor having molecular weight between 14.2 and 16.2 kDa was found to be primarily responsible for the differences observed in the urinary IAs between normal persons and kidney stone patients. The potent inhibitor was found to be tightly associated with a chromophore resembling Urobilirubin. An ELISA based assay system, using monoclonal antibodies against the above most potent inhibitor confirmed the difference observed in the urinary IA between the normal persons and kidney stone patients. This assay system has the potential to be routinely used to screen human beings for potential stone formers.

Adult↗

Treatment of coexistent coarctation and aneurysm of the aorta with covered stent in a pediatric patient.

Intravascular stents have emerged as an effective alternative to surgery and balloon angioplasty in the treatment of native and recoarctation of aorta. Balloon angioplasty, although effective in the treatment of native coarctation of the aorta, is associated with several complications such as recoarctation, aneurysm formation, aortic dissection, and vascular injury. In this report, we present the use of a covered stent to treat a patient who developed recoarctation of the aorta with an associated aneurysm following balloon angioplasty of her native coarctation.

Adolescent↗

Contribution of capsular and lipopolysaccharide antigens to the pathogenesis of Klebsiella pneumoniae respiratory tract infection.

The role of Klebsiella pneumoniae K- and O-polysaccharide antigens was determined in a rat model of lobar pneumonia. The induction of experimental infection in rats by wild-type strain, and its lipopolysaccharide- and capsular polysaccharide-deficient mutants was compared. Though the mutant lacking both antigens (K- O-) induced infection it could not successfully establish itself in the rat lung. It caused only mild infection, as compared to the wild type strain (K+ O+) and the strain lacking CPS alone (K- O+). Besides capsular polysaccharide, the lipopolysaccharide antigen was shown to be an important factor in pathogenesis of K. pneumoniae acute respiratory tract infection.

Animals↗

Studies on solubility and hypoglycemic activity of gliclazide beta-cyclodextrin-hydroxypropylmethylcellulose complexes.

This study was undertaken with an objective to increase the dissolution rate and bioavailability of a poorly water soluble drug gliclazide (Gz) by complexation with beta-cyclodextrin (CD) in the presence of hydroxypropylmethylcellulose (HPMC). Phase solubility studies of Gz were performed in aqueous solutions of different concentrations of CD alone and in the presence of some water soluble polymers. Gz-CD complexes were prepared in 1:1 and 1:2 drug:CD molar ratios by autoclaving, neutralization and kneading methods. The complexes were also prepared in the presence of 0.05% w/w HPMC. Physical mixtures of Gz-CD in 1:1 and 1:2 molar ratios were also prepared. Complexes and physical mixtures were characterized and evaluated for in vitro dissolution in distilled water and hypoglycemic activity in rats. CD enhanced the dissolution of Gz to 1.5 to 2.0 fold. Presence of water soluble polymer HPMC in Gz-CD complexes further enhanced the rate and extent of drug dissolution to 2.5 fold. Gz-CD-HPMC complexes were found to be more promising as they produced not only an early onset but also more intense hypoglycemic effect as compared to pure drug powder and commercial tablets.

Animals↗

Forced expression of murine IL-17E induces growth retardation, jaundice, a Th2-biased response, and multiorgan inflammation in mice.

IL-17 is a proinflammatory cytokine, and its in vivo expression induces neutrophilia in mice. IL-17E is a recently described member of an emerging family of IL-17-related cytokines. IL-17E has been shown to bind IL-17Rh1, a protein distantly related to the IL-17R, suggesting that IL-17E probably possesses unique biological functions. In this study, we have identified the murine ortholog of IL-17E and developed transgenic mice to characterize its actions in vivo. Biological consequences of overexpression of murine (m)IL-17E, both unique to IL-17E and similar to IL-17, were revealed. Exposure to mIL-17E resulted in a Th2-biased response, characterized by eosinophilia, increased serum IgE and IgG1, and a Th2 cytokine profile including elevated serum levels of IL-13 and IL-5 and elevated gene expression of IL-4, IL-5, IL-10, and IL-13 was observed in many tissues. Increased gene expression of IFN-gamma in several tissues and elevated serum TNF-alpha were also noted. In addition, IL-17E induces G-CSF production in vitro and mIL-17E-transgenic mice had increased serum G-CSF and exhibit neutrophilia, a property shared by IL-17. Moreover, exposure to mIL-17E elicited pathological changes in multiple tissues, particularly liver, heart, and lungs, characterized by mixed inflammatory cell infiltration, epithelial hyperplasia, and hypertrophy. Taken together, these findings suggest that IL-17E is a unique pleiotropic cytokine and may be an important mediator of inflammatory and immune responses.

3T3 Cells↗

B-subunit of phosphate-specific transporter from Mycobacterium tuberculosis is a thermostable ATPase.

The B-subunit of phosphate-specific transporter (PstB) is an ABC protein. pstB was polymerase chain reaction-amplified from Mycobacterium tuberculosis and overexpressed in Escherichia coli. The overexpressed protein was found to be in inclusion bodies. The protein was solubilized using 1.5% N-lauroylsarcosine and was purified by gel permeation chromatography. The molecular mass of the protein was approximately 31 kDa. The eluted protein showed ATP-binding ability and exhibited ATPase activity. Among different nucleotide triphosphates, ATP was found to be the preferred substrate for M. tuberculosis PstB-ATPase. The study of the kinetics of ATP hydrolysis yielded K(m) of approximately 72 microm and V(max) of approximately 0.12 micromol/min/mg of protein. Divalent cation like manganese was inhibitory to the ATPase activity. Magnesium or calcium, on the other hand, had no influence on the functionality of the enzyme. The classical ATPase inhibitors like sodium azide, sodium vanadate, and N-ethylmaleimide were without any effect but an ATP analogue, 5'-p-fluorosulfonylbenzoyl adenosine, inhibited the ATPase function of the recombinant protein with a K(i) of approximately 0.40 mm. Furthermore, there was hardly any ATP hydrolyzing ability of the PstB as a result of mutation of the conserved aspartic acid residue to lysine in the Walker motif B, confirming the recombinant protein is an ATPase. Interestingly, analysis of the recombinant PstB revealed that it is a thermostable ATPase; thus, our results highlight for the first time the presence of such an enzyme in any mesophilic bacteria.

ATP-Binding Cassette Transporters↗