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Biomedical subjects

S K Bhatnagar

Publications and source records attributed to S K Bhatnagar.

At least 19 recordsLinked to original sources
PubMed2005

Archform in cleft palate--a computerized tomographic classification.

This prospective study was conducted in King George's Medical College, Lucknow, India amongst fifty cleft lip and palate cases to study the various arch forms. The maxillary arch form was traced from Computer Tomograph sections of all the cases pre and post-operatively. The various patterns of arch forms as observed from CT tracings exhibiting U & V shaped with sub-types denominated as posteriorly--convergent (c), divergent (d) and parallel (p). This simplified classification can be used in pediatric dentistry practice.

Child↗
PubMed2002

Mapping and characterisation of QTL x E interactions for traits determining grain and stover yield in pearl millet.

A mapping population of 104 F(3) lines of pearl millet, derived from a cross between two inbred lines H 77/833-2 x PRLT 2/89-33, was evaluated, as testcrosses on a common tester, for traits determining grain and stover yield in seven different field trials, distributed over 3 years and two seasons. The total genetic variation was partitioned into effects due to season (S), genotype (G), genotype x season interaction (G x S), and genotype x environment-within-season interaction [G x E(S)]. QTLs were determined for traits for their G, G x S, and G x E(S) effects, to assess the magnitude and the nature (cross over/non-crossover) of environmental interaction effects on individual QTLs. QTLs for some traits were associated with G effects only, while others were associated with the effects of both G and G x S and/or G, G x S and G x E(S) effects. The major G x S QTLs detected were for flowering time (on LG 4 and LG 6), and mapped to the same intervals as G x S QTLs for several other traits (including stover yield, harvest index, biomass yield and panicle number m(-2)). All three QTLs detected for grain yield were unaffected by G x S interaction however. All three QTLs for stover yield (mapping on LG 2, LG 4 and LG 6) and one of the three QTLs for grain yield (mapping on LG 4) were also free of QTL x E(S) interactions. The grain yield QTLs that were affected by QTL x E(S) interactions (mapping on LG 2 and LG 6), appeared to be linked to parallel QTL x E(S) interactions of the QTLs for panicle number m(-2) on (LG 2) and of QTLs for both panicle number m(-2) and harvest index (LG 6). In general, QTL x E(S) interactions were more frequently observed for component traits of grain and stover yield, than for grain or stover yield per se.

Chromosome Mapping↗
PubMed2001

Rational antibiotics therapy in bacterial meningitis.

Acute bacterial meningitis is one of the most important causes of morbidity and mortality in developing countries. Though a wide range of antibiotics is available for therapy, judicious and rational use of antimicrobial agents needs to be ascertained. The choice of antimicrobial agents depends mainly on the age of the patient and its CSF penetrability. Neonatal meningitis is commonly caused by Gram Negative organisms such E. coli, Klebsiella and Pseudomans;Group B streptococciand Listeria, though other organisms like Staphylococcus sp. also contribute. The neonatal meningitis is best treated with a combination of amplicillin and a third generation cephalosporin given for 14-21 days. Post-neonatal meningitis usually occurs due to S. pneumoniae, N. meningitidis and H. influenzae and is best treated with third generation cephalosporins used with or without crystalline penicillin or ampicillin depending on the clinical situation. The therapy should be modified, if necessary, on availability of culture sensitivity report. The use of dexamethasone in meningitis due to the organisms other than H. influenzae still remains controversial.

Adolescent↗
PubMed2000

Idiopathic pulmonary haemosiderosis.

Idiopathic pulmonary haemosiderosis (IPH) is a rare disorder characterized by recurrent bouts of haemoptysis, iron deficiency anaemia, and pulmonary infiltrates on chest radiograph. We present such a case and believe that it is the first report from the Middle East.

Child, Preschool↗
PubMed1998

Nasal sill augmentation in adult incomplete cleft lip nose deformity using superiorly based turn over orbicularis oris muscle flap: an anatomic approach.

Adult incomplete cleft lip nose deformity is not uncommon in India. Poverty, ignorance, and parental neglect account for its late presentation. Besides the classical features of cleft lip nose deformity, the constant findings observed in this patient population have been a widened and depressed nasal sill. This is attributable to the sparse, hypoplastic, and abnormally orientated orbicularis oris muscle in the region of the sill. Failure to restore the nasal sill symmetry by suitably augmenting the sill frequently leads to unsatisfactory and asymmetric results. However, in the literature, satisfactory restoration of the nasal sill has not been given the importance it deserves while performing cleft lip rhinoplasty. We present a method of augmenting the depressed nasal sill in cases of adult incomplete nose deformity using a superiorly based orbicularis oris muscle flap, which is harvested from the soft tissues between the apex of the cleft and the nostril sill. Following de-epithelialization of the overlying skin, the exposed muscle is raised as a superiorly based flap after dissecting it from the underlying mucosa. It is folded, turned over, and tucked into the nasal sill base and anchored to the anterior nasal spine to give the desired augmentation. Satisfactory results have been obtained in 18 cases of nasal deformity associated with incomplete cleft lip. In our opinion, this technique offers a simple and effective method of augmenting the depressed sill by utilizing locally available tissues and without the need for procuring autologous tissue from distant sites.

Adolescent↗
PubMed1997

A closed tube format for amplification and detection of DNA based on energy transfer.

A new method for the direct detection of PCR-amplified DNA in a closed system is described. The method is based on the incorporation of energy transfer-labeled primers into the amplification product. The PCR primers contain hairpin structures on their 5'ends with donor and acceptor moieties located in close proximity on the hairpin stem. The primers are designed in such a way that a fluorescent signal is generated only when the primers are incorporated into an amplification product. A signal to background ratio of 35:1 was obtained using the hairpin primers labeled with fluorescein as a donor and 4-(4'-dimethylaminophenylazo) benzoic acid (DABCYL) as a quencher. The modified hairpin-primers do not interfere with the activity of DNA polymerase, and both thermostable Pfu and Taq polymerase can be used. This method was applied to the detection of cDNA for prostate specific antigen. The results demonstrate that the fluorescent intensity of the amplified product correlates with the amount of incorporated primers, and as few as 10 molecules of the initial template can be detected. This technology eliminates the risk of carry-over contamination, simplifies the amplification assay and opens up new possibilities for the real-time quantification of the amplified DNA over an extremely wide dynamic range.

Base Sequence↗
PubMed1996

Transesophageal echocardiographic assessment of papillary muscle rupture.

BACKGROUND: In some patients with papillary muscle rupture, the ruptured head may not prolapse into the left atrium, which makes diagnosis by transthoracic or transesophageal echocardiography difficult. METHODS AND RESULTS: In an attempt to find additional or more definite diagnostic echocardiographic features, we analyzed intraoperative transesophageal echocardiograms of 21 consecutive patients with papillary muscle rupture (20 involved the left ventricle and 1 involved the right ventricle) confirmed at surgery. In 7 (35%) of 20 patients with left ventricular papillary muscle rupture, the ruptured head was not seen to prolapse into the left atrium. In these patients, examination of the left ventricle proved most useful. Abnormal, large-amplitude erratic motion (1 to 5 cm in 17 patients; 0.5 cm in 1 patient) of a large echo density in the left ventricle consistent with the ruptured head was noted in 18 (90%) of these 20 patients. This included all 7 patients with non-prolapse of the ruptured papillary muscle head into the left atrium. Less prominent erratic motion or flutter of the papillary muscle still attached to the left ventricular wall was also noted but was less sensitive in the diagnosis of papillary muscle rupture. The single patient with right ventricular papillary muscle rupture showed erratic motion as well as prolapse of the ruptured head into the right atrium. CONCLUSIONS: Transesophageal echocardiographic examination of the left ventricle is useful in the diagnosis of papillary muscle rupture, especially in those patients in whom the ruptured head does not prolapse into the left atrium. The left ventricle should be scrutinized thoroughly during transesophageal echocardiographic examination for erratic papillary muscle motion in all patients with suspected rupture.

Adult↗
PubMed1996

Hemophilus influenzae septic arthritis and pneumonia in an adult as the first presentation of multiple myeloma.

We describe an apparently healthy woman who presented with monoarthritis of the right knee and a history of respiratory infection. The synovial fluid cultures grew beta lactamase-negative H. influenzae. Chest roentgenogram showed patchy densities throughout the right lung. Investigations for a predisposing factor for this H. influenzae infection revealed underlying multiple myeloma. As H. influenzae pyoarthrosis is extremely rare in adults, we suggest that an underlying systemic cause be sought in all such patients.

Aged↗
PubMed1994

Observations of the relationship between left ventricular aneurysm and ST segment elevation in patients with a first acute anterior Q wave myocardial infarction.

Seventy-eight consecutive survivors of a first acute anterior Q wave myocardial infarction (AMI) underwent two-dimensional echocardiography (2D echo), colour Doppler echo and radionuclide angiography (RNA) for the diagnosis of left ventricular (LV) anteroapical aneurysm, in order to study the relationship of this complication to precordial ST segment elevation in these patients. The ST elevation (mm) in lead V2, the maximum ST elevation in V1-V6 and the sum of ST elevation in V1 to V6 were calculated. LV aneurysm was present in 19 patients by 2D echo, of whom 12 had a paradoxical systolic flow pattern (red and outward towards the transducer) at the apex. There was no difference between the mean ST elevation in V2 or the maximum ST elevation in V1-V6 in patients with and without an aneurysm, although the sum of ST elevations in V1 to V6 was higher in the former group (P < 0.01). ST elevation of patients with and without paradoxical systolic flow also did not differ significantly. Wall motion abnormality (akinesis and dyskinesis) by 2D echo in the anterior wall was seen in 74% of patients with and 36% of patients without an aneurysm (P < 0.005), and in the septal region in 63% and 47% of respective patients (P-NS). There was no difference between the magnitude of ST elevation in subgroups of patients with ejection fraction (EF) < or = 30% to > or = 40%, but the mean EF of patients with (23 +/- 2.1%) and without a LV aneurysm (34 +/- 1.3%) differed (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiography↗
PubMed1992

NMR and isotopic exchange studies of the site of bond cleavage in the MutT reaction.

The MutT protein, which prevents AT----CG transversions during DNA replication, hydrolyzes nucleoside triphosphates to yield nucleoside monophosphates and pyrophosphate. The hydrolysis of dGTP by the MutT protein in H(2)18O-enriched water, when monitored by high resolution 31P NMR spectroscopy at 242.9 MHz, showed 18O labeling of the pyrophosphate product, as manifested by a 0.010 +/- 0.002 ppm upfield shift of the pyrophosphate resonance, and no labeling of the dGMP product. This establishes that the reaction proceeds via a nucleophilic substitution at the beta-phosphorus of dGTP with displacement of dGMP as the leaving group. No exchange of 32P-labeled dGMP into dGTP was detected, indicating that water attacks dGTP directly or, less likely, an irreversibly formed pyrophosphoryl-enzyme intermediate. No exchange of 32P-labeled pyrophosphate into dGTP was observed, consistent with nucleophilic substitution at the beta-phosphorus of dGTP. Only six enzymes, all synthetases, have previously been shown to catalyze nucleophilic substitution at the beta-phosphorus of nucleoside triphosphate substrates. The MutT protein is the first hydrolase shown to do so.

Bacterial Proteins↗
PubMed1992

Management of burn contractures of the first web space of the hand.

First web space contractures of the hand affect predominantly the movements at the trapeziometacarpal joint, rendering the thumb ineffective for opposition and thereby destroying the essential elements of grasp and pinch. Adequate release of contractured first web space followed by a local skin flap cover and dynamic abduction splintage for the subsequent 6 weeks gives excellent results. Documenting the first web angle at every follow-up visit can detect early recurrences and the dynamic splintage can be reinstituted to achieve the normal first web space. Secondary surgery in the form of flexor pollicis longus tendon lengthening or opponens-plasty helps to prevent recurrences.

Burns↗
PubMed1992

Left ventricular blood flow analysis in patients with and without a thrombus after first Q wave acute anterior myocardial infarction: two-dimensional Doppler echocardiographic study.

The authors studied 80 consecutive patients with a first Q wave anterior myocardial infarction (MI) by 2-dimensional and color Doppler echocardiography (echo), on day 3 and day 10 after admission, to determine whether left ventricular (LV) blood flow dynamics differ between those who develop LV thrombus and those who do not. With pulsed Doppler echo, peak flow velocities were measured in diastole at the inflow tract, at the apex in diastole and systole, and at the outflow tract in systole. There were 11 patients (14%) who had LV thrombosis on day 3. On day 10, no other patient developed a thrombus. There was no difference in the Doppler flow velocities, except for lower apical diastolic velocities (0.23 +/- 0.04 m/s) (+/- SEM) in patients with thrombus as compared with those without it (0.33 +/- 0.01 m/s) (p less than 0.05). All patients with thrombus had apical dyskinesis and 8 (73%) had an anteroapical aneurysm, while 40 (58%) patients without thrombosis had dyskinesis and 11 (16%) had an aneurysm (p less than 0.01). The ejection fraction was lower (25.4 +/- 3.2%), the wall motion score was higher (10.6 +/- 0.7), and mitral regurgitation was seen more frequently (45%) in those with LV thrombus (respective values in no thrombus group patients: 32.9 +/- 1.4%, 7.6 +/- 0.3, 7%). The authors conclude that LV thrombus prediction is difficult by Doppler flow velocity study, whereas dyskinesis and aneurysmal dilatation of the LV apex is significantly associated with thrombus.

Adult↗
PubMed1991

Characterization of the mutT nucleoside triphosphatase of Escherichia coli.

The mutT protein, which prevents A:T----C:G transversions during DNA replication, has the following enzymatic properties. Although it prefers dGTP as a substrate, it hydrolyzes all of the canonical nucleoside triphosphates to some extent. It has no activity in the absence of divalent cations, is maximally activated by magnesium ions, and has a pH optimum of 9.0. Nucleoside triphosphates are hydrolyzed according to the following equation. dGTP----dGMP + PPi Studies with nucleotide analogues suggest that the enzyme may prefer the syn rather than the anti conformation of the nucleoside triphosphates, which might explain the role it plays in preventing mutations.

Base Sequence↗
PubMed1991

Crystallization and preliminary X-ray diffraction studies on the mutT nucleoside triphosphate pyrophosphohydrolase of Escherichia coli.

The mutT nucleoside triphosphatase, which prevents AT----CG transversions during DNA replication, has been crystallized from ammonium sulfate utilizing a novel technique involving vapor diffusion in capillaries. X-ray diffraction analysis has revealed that the crystals are monoclinic, space group P2(1), with cell constants a = 34.14, b = 72.54, c = 56.38, and beta = 98.90. The Vm value of 2.31 A3/Da is consistent with two molecules of enzyme per asymmetric unit. The crystals are reasonably stable in the x-ray beam, and a data set to 2.5 A resolution has been collected for native protein. There is evidence that the crystals diffract to at least 2.1 A.

Crystallography↗
PubMed1991

Effects of intravenous recombinant tissue-type plasminogen activator therapy on the incidence and associations of left ventricular thrombus in patients with a first acute Q wave anterior myocardial infarction.

Consecutive survivors of a first Q wave anterior myocardial infarction were studied to observe the impact of recombinant tissue-type plasminogen activator (rt-PA) therapy on the incidence and associations of left ventricular thrombus. Fifty-four patients received rt-PA within 4 hours after the onset of cardiac pain, followed by heparin infusion. Forty-four patients who did not qualify for rt-PA therapy but who were anticoagulated with heparin served as a control group. Two-dimensional echocardiography was performed in all patients on days 3 and 7 to detect thrombi and analyze wall motion. Ejection fraction was determined by radionuclide angiography in all patients on day 7. Apical thrombi were detected on day 3 in three patients (5.5%) who received rt-PA and in eight control patients (18%) (p less than 0.05). All patients with a thrombus had apical dyskinesis and 8 of 11 (73%) had an aneurysm. Of the 87 patients without thrombosis, apical dyskinesis and aneurysm were present in 42 (48%) and 11 (13%) patients, respectively (p less than 0.01). Ejection fractions and wall motion scores of patients without a thrombus were significantly better when compared with data from those with a thrombus. There were fewer patients with apical dyskinesis (17 of 54) in the group receiving rt-PA therapy compared with the control group (36 of 44) (p less than 0.01). Ejection fractions and wall motion scores were better in patients who received rt-PA compared with control subjects (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiography↗
PubMed1991

The medial upper arm fasciocutaneous flap. An alternative flap to cover palmar defects of hand and distal forearm.

Cutaneous defects on the palmar aspect of the hand and distal forearm can usually be covered by split skin grafts or, if the defect is small, by local flaps. However, for larger defects, especially in acute injuries where preservation of functional parts like nerves and tendons is in jeopardy and particularly when further surgery is contemplated, flap coverage becomes essential. Such a flap, besides being uniformly dependable and cosmetically acceptable, must have a reasonable position of immobilization, must be easy to nurse and must not hamper the daily routine of the patient. The medial upper arm fasciocutaneous flap, both distally based and proximally based appears, after a critical evaluation, to be the best answer to this problem short of a microvascular free flap.

Adolescent↗