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Biomedical subjects

K Aggarwal

Publications and source records attributed to K Aggarwal.

At least 19 recordsLinked to original sources
PubMed2002

Bilateral groove sign with penoscrotal elephantiasis.

Lymphogranuloma venereum (LGV) is a sexually transmitted disease of the lymph channels caused by Chlamydia trachomatis. Esthiomene, a rare late manifestation of LGV, is a primary infection affecting the lymphatics of scrotum, penis, or vulva. The male genitalia are affected less commonly by esthiomene, but we report a male patient who presented with inguinal syndrome, penoscrotal elephantiasis, along with enlargement of femoral lymph nodes.

Adult↗
PubMed2001

Helical peptide models for protein glycation: proximity effects in catalysis of the Amadori rearrangement.

INTRODUCTION: Non-enzymatic glycation of proteins has been implicated in various diabetic complications and age-related disorders. Proteins undergo glycation at the N-terminus or at the epsilon-amino group of lysine residues. The observation that only a fraction of all lysine residues undergo glycation indicates the role of the immediate chemical environment in the glycation reaction. Here we have constructed helical peptide models, which juxtapose lysine with potentially catalytic residues in order to probe their roles in the individual steps of the glycation reaction. RESULTS: The peptides investigated in this study are constrained to adopt helical conformations allowing residues in the i and i+4 positions to come into spatial proximity, while residues i and i+2 are far apart. The placing of aspartic acid and histidine residues at interacting positions with lysine modulates the steps involved in early peptide glycation (reversible Schiff base formation and its subsequent irreversible conversion to a ketoamine product, the Amadori rearrangement). Proximal positioning of aspartic acid or histidine with respect to the reactive lysine residue retards initial Schiff base formation. On the contrary, aspartic acid promotes catalysis of the Amadori rearrangement. Presence of the strongly basic residue arginine proximate to lysine favorably affects the pK(a) of both the lysine epsilon-amino group and the singly glycated lysine, aiding in the formation of doubly glycated species. The Amadori product also formed carboxymethyl lysine, an advanced glycation endproduct (AGE), in a time-dependent manner. CONCLUSIONS: Stereochemically defined peptide scaffolds are convenient tools for studying near neighbor effects on the reactivity of functional amino acid sidechains. The present study utilizes stereochemically defined peptide helices to effectively demonstrate that aspartic acid is an efficient catalytic residue in the Amadori arrangement. The results emphasize the structural determinants of Schiff base and Amadori product formation in the final accumulation of glycated peptides.

Aspartic Acid↗
PubMed2001

Minute ventilation-sensor driven pacemaker related difficulty in weaning from mechanical ventilation: a case report.

BACKGROUND: Minute ventilation responsive rate adaptive pacemaker improves exercise performance in the patients with chronotropic insufficiency. The usual complications of these pacemakers are related to pacemaker implantation, rather than to the rate adaptive function. CASE REPORT: We report a patient with mitral stenosis and atrial fibrillation with a VVIR pacemaker, who was mechanically ventilated for respiratory failure. The patient could not be weaned because of the minute ventilation driven increased heart rates. Subsequently the rate adaptive function was switched off and the patient was successfully weaned from ventilator. CONCLUSIONS: Difficulty in weaning from mechanical ventilation can be a serious complication in patients with organic heart disease, who depend on diastolic filling time for adequate cardiac output.

Aged↗
PubMed2000

Left main coronary artery rotational atherectomy and stenting.

BACKGROUND: Coronary artery bypass surgery is a difficult option in patients who are not candidates for bypass surgery and high-risk patients with critical left main coronary artery (LMCA) disease. We report outcomes and short-term follow-up of patients who had LMCA rotational atherectomy and/or stenting, assess the role of these interventions in protected and unprotected significant LMCA stenosis, and review the literature. METHODS: We reviewed the cases of seven men with critical LMCA stenosis for whom coronary artery bypass surgery was considered a high risk. Five patients had rotational atherectomy, one had coronary artery stenting, and one had both. RESULTS: In all cases, angiographic success was achieved, and symptoms were relieved. Six patients were discharged from the hospital in 3 to 6 days. One patient who had cardiogenic shock, respiratory failure, and acute renal failure before the procedure died of arrhythmia 4 days afterward. Another patient had elective coronary artery bypass graft surgery 3 weeks later for recurrent angina. Cardiac catheterization was repeated in 1 month for chest pain in three patients at 4 to 7 months follow-up, and none had progression of residual stenosis in the LMCA. CONCLUSIONS: Our study suggests that LMCA rotational atherectomy and stenting are safe and effective revascularization procedures in high-risk patients and patients who are not candidates for bypass surgery.

Aged↗
PubMed1996

Atheroembolic disease following administration of tissue plasminogen activator (TPA).

Atheroembolic disease is an uncommon condition with many interesting manifestations and has been reported following various procedures. Its occurrence following thrombolytic therapy is extremely rare, with only a few case reports in the literature. However, with a widespread application of thrombolysis in patients with acute myocardial infarction, its incidence is likely to increase and therefore this entity needs to be recognized. Early recognition of the illness may help avoid further expensive and unnecessary investigations. We report two cases of atheroembolic disease following the administration of human recombinant tissue plasminogen activator (TPA).

Aged↗
PubMed1993

The biologic activity of ACTH and related peptides on peripheral blood mononuclear cells is altered by the presence of dexamethasone.

We wished to determine whether the glucocorticoid hormone dexamethasone (dex), a potent modular of both pituitary-adrenal and immunologic activity, altered the effect of adrenocorticotropin-related peptides on activated peripheral blood mononuclear cells (PBMCs) and T-cells. PBMCs preactivated with Concanavalin A (Con A) and T-cells preactivated with phorbol 12,13 dibutyrate (PDB) plus phytohemagglutinin (PHA) were exposed to dex, ACTH, and related peptide sequences. Proliferation of cells was measured as was IL-2 in conditioned media. It was found that in the absence of dex only the peptide ACTH(18-39) altered proliferation of PBMCs while there was no effect of peptide on T-cells activated via protein kinase C-mediated pathways. Significant reversal of the inhibitory effect of dex on proliferation of PBMCs exposed to Con A was achieved with addition of ACTH(1-39) and ACTH(11-24), while IL-2 levels were unaffected by the addition of peptide. ACTH(18-39) and ACTH(11-24) enhanced the inhibitory effect of dex on T-cells activated with PDB plus PHA. These findings suggest that the biologic activity of ACTH on immune cells is altered when dexamethasone is present and under certain circumstances ACTH may protect the immunologic response from the inhibitory effects of elevated ambient glucocorticoids.

Adrenocorticotropic Hormone↗
PubMed1986

Prevalence of dental caries and associated teeth cleaning habits among children in four primary schools.

A study was conducted in four primary schools of Mehrauli block of rural Delhi. Four hundred and fifty eight primary school children of both sexes in the age group of 5-14+ were medically examined in daylight using a mouth mirror and probe. The children came from low socioeconomic backgrounds. Presence of clinical caries was recorded by naked eye examination. Dental caries prevalence was 33.19% and DMF index was 0.52. Teeth cleaning habits of the school children in terms of regularity and associated caries prevalence was also noted. The 'Regular' teeth cleaning group showed significantly less caries prevalence while 'Not Regular' and 'Never Cleaning' groups had higher caries prevalence. Since childhood is such an impressionable age all students were made aware of the need for proper oral hygiene to minimize the incidence of caries among them.

Adolescent↗
PubMedDate not supplied

Aortic flow velocity patterns in chronic aortic regurgitation: implications for Doppler echocardiography.

Aortic regurgitation is associated with retrograde diastolic flow in the aorta. Echocardiographic quantitative analysis of the magnitude of the flow reversal is believed to provide an estimate of severity of regurgitant disease despite variations in flow profiles. The purpose of this study was to evaluate the uniformity of flow patterns in the aorta of patients with aortic regurgitation and to investigate the relationship between these profiles and the echocardiographic estimates of flow reversal. Seventeen patients with chronic aortic regurgitation underwent cine-phase magnetic resonance imaging in an axial section through the ascending and descending aorta. The regurgitant fraction in the ascending aorta 4 cm above the aortic valve and the descending aorta were calculated from the velocity maps. These results were compared with data from nine individual sample volumes in the ascending and descending aorta. The magnetic resonance ascending aortic regurgitant fraction was compared with Doppler echocardiographic descending aortic flow velocity patterns. The descending aortic regurgitant fraction correlated only weakly with the ascending aortic regurgitant fraction (descending aortic regurgitant fraction = 0.62% ascending aortic regurgitant fraction + 0.04%; r = 0.75; p < 0.001). Regurgitant proportions in all sample volumes in the descending aorta, but not in the ascending aorta, were significantly related to the ascending aortic regurgitant fraction. The best descending aortic Doppler echocardiographic parameter for predicting ascending aortic regurgitant fraction was the end-diastolic velocity (end-diastolic velocity = 32.2 cm/sec. ascending aortic regurgitant fraction + 1.4 cm/sec; r = 0.94; p < 0.001). Pulsedwave Doppler sampling of descending aortic flow reflects severity of aortic regurgitant disease, in part the result of more uniform blood-velocity profiles in the descending aorta compared with the ascending aorta. The Doppler end-diastolic velocity in the descending aorta is a useful parameter of severity of aortic regurgitation.

Aorta↗
PubMedDate not supplied

Role of corticosteroids in the management of chronic obstructive lung disease: factors predicting response.

A double-blind crossover trial of prednisolone was conducted in 70 patients of chronic obstructive lung disease (COLD). Emphysema dominated the clinical picture in 38, rest being chronic bronchitis with varying degrees of air trapping. None of the patients had clinical asthma. All the patients had obtained maximal benefit from an optimal dose of bronchodilators prior to entering the study. Prednisolone in a dose of 0.8 mg/kg was prescribed in a double blind crossover manner with identical appearing placebo tablets. Patients were evaluated on a weekly basis for an objective as well as a subjective response and side effects of therapy. Thirty-four patients demonstrated a statistically significant improvement in pulmonary functions. In 20 others only subjective response was observed. A good objective response was predicted by a pre-study variability in FEV1, disease duration of less than 10 years and a history of smoking less than 50 pack years.

Bronchitis↗