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Biomedical subjects

K Pandey

Publications and source records attributed to K Pandey.

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

Biochemical, biophysical, and functional characterization of bacterially expressed and refolded receptor binding domain of Plasmodium vivax duffy-binding protein.

Invasion of erythrocytes by malaria parasites is mediated by specific molecular interactions. Plasmodium vivax is completely dependent on interaction with the Duffy blood group antigen to invade human erythrocytes. The P. vivax Duffy-binding protein, which binds the Duffy antigen during invasion, belongs to a family of erythrocyte-binding proteins that also includes Plasmodium falciparum sialic acid binding protein and Plasmodium knowlesi Duffy binding protein. The receptor binding domains of these proteins lie in a conserved, N-terminal, cysteine-rich region, region II, found in each of these proteins. Here, we have expressed P. vivax region II (PvRII), the P. vivax Duffy binding domain, in Escherichia coli. Recombinant PvRII is incorrectly folded and accumulates in inclusion bodies. We have developed methods to refold and purify recombinant PvRII in its functional conformation. Biochemical, biophysical, and functional characterization confirms that recombinant PvRII is pure, homogeneous, and functionally active in that it binds Duffy-positive human erythrocytes with specificity. Refolded PvRII is highly immunogenic and elicits high titer antibodies that can inhibit binding of P. vivax Duffy-binding protein to erythrocytes, providing support for its development as a vaccine candidate for P. vivax malaria. Development of methods to produce functionally active recombinant PvRII is an important step for structural studies as well as vaccine development.

Amino Acid Sequence↗
PubMed2001

Color Doppler sonographic diagnosis of dissecting aneurysm of the superior mesenteric artery.

We report a case of dissecting aneurysm of the superior mesenteric artery (SMA) diagnosed on gray-scale and color Doppler sonography and confirmed on angiography. Spontaneous dissection of the SMA is rare, and there are few reported cases of the color Doppler sonographic findings. Gray-scale sonography revealed an aneurysmal dilatation of the SMA 3-4 cm from the SMA's origin, with an echogenic linear membrane (an intimal flap) within the aneurysm. Color Doppler sonography showed color flow within the aneurysm and showed that the intimal flap separated the aneurysm into 2 lumina. Spectral analysis revealed anterograde flow in the anterior (ie, true) lumen and retrograde flow in the posterior (ie, false) lumen.

Aortic Dissection↗
PubMed1999

Early experience with partial left ventriculectomy in the Asia-Pacific region.

BACKGROUND: We report our early experience with partial left ventriculectomy done by a group of cardiac surgeons in the Asia-Pacific region. METHODS: Partial left ventriculectomy was done in 48 patients (mean age, 43 years) with advanced symptomatic cardiomyopathy. The origin of cardiomyopathy was idiopathic in 30 patients, valvular in 10, ischemic in 3, peripartum in 3, sarcoidosis in 1, and viral myocarditis in 1. Procedures performed on the mitral valve were repair with Alfieri method in 8 patients, ring annuloplasty in 2, and replacement in 25. RESULTS: Seventy-seven percent of patients required myocardial support for weaning from cardiopulmonary bypass, and the overall in-hospital mortality rate was 27%. Mean follow up was 6.5 months (range, 1 to 18 months), and patient survival at 1, 3, and 6 months after discharge was 91%, 88%, and 84%, respectively. Sixty-five percent of survivors with idiopathic and valvular disease achieved significant and sustained improvement in ventricular contractility and symptoms, but there were no clear symptomatic benefits from partial left ventriculectomy in patients with cardiomyopathy from other causes. Most cases of late recurrence of heart failure symptoms (90%) appeared to be related to the development of progressive mitral incompetence. CONCLUSIONS: After partial left ventriculectomy left ventricular function improved in patients with idiopathic and valve related cardiomyopathies. Late deterioration was related to the development of significant mitral valve incompetence postoperatively, hence definitive mitral valve repair or replacement at the time of the partial left ventriculectomy procedure is advised.

Adolescent↗
PubMed1992

Fine needle aspiration cytology in the diagnosis of prostatic enlargements.

One hundred patients with enlarged prostate were subjected to fine needle aspiration cytology and histopathologic examination of prostate. The results have been found encouraging. The cytodiagnostic accuracy rate was 99 p.c. in identification of benign or malignant nature of the lesions and 94 p.c. in cytologic specific diagnosis (exactly similar to histopathologic diagnosis). The technique was simple, rapid, economical, reliable, easy to repeat and highly suitable for outpatients. The procedure can routinely be adopted in places where facilities for preparation of paraffin section do not exist or when quick diagnosis is required.

Biopsy, Needle↗
PubMed1990

Testing of adsorbed diphtheria-pertussis-tetanus (DPT) vaccine for freedom from abnormal toxicity.

A total of 112 samples of adsorbed DPT vaccine were tested in mice for freedom from abnormal toxicity by three procedures: (a) single human dose by intraperitoneal route; (2) single human dose by subcutaneous route; and (3) half the single human dose by intraperitoneal route. The percentage of samples passing by the three methods was 25, 90 and 54.5, respectively. Method 3, which is being recommended now by the World Health Organization, is supported by the results of this study to be neither very stringent nor very lenient to pass the adsorbed DPT vaccine for freedom from abnormal toxicity.

Animals↗
PubMed1985

Effect of thiourea on the testicular steroidogenesis and secondary sexual characters of a tropical freshwater fish, Mystus (M) vittatus (Bloch).

300 ppm of thiourea solution was found to produce significant decline in the interstitial cells of the testes of Mystus (M) vittatus. The regressive changes have been observed both in the number and the size (diameter) of these cells. The thiourea though could not bring about appreciable changes up to the second week, but during third and fourth week marked cellular regression in the interstitial cells has been recorded. Such cellular changes appear to influence the development of the genital papilla and caudal thickening (the secondary sexual characters - SSC) in the male specimens. Changes in the interstitial cells indicative of gonadal steroidogenesis correlated with the SSC is for the first time reported in a tropical fish. Interesting findings have been described and discussed.

Animals↗
PubMed1984

Impaired ovarian functions in arsenic-treated freshwater fish, Colisa fasciatus (bl. and sch.).

Arsenic(III) oxide (2.0 mg/l) after 15 and 30 days exposure, and 14.0 mg/l concentration after 15 days exposure, produced no marked histological alteration in the ovary of Colisa fasciatus during its mature phase, whereas 14.0 mg/l arsenic(III) oxide concentration after 30 days exposure decreased the development of oocyte (II and III stage), reduced the number and diameter of nucleoli and increased the number of atretic follicles. The possible mechanism for these alterations is discussed.

Animals↗
PubMed1984

Impaired spermatogenesis in arsenic treated freshwater fish, Colisa fasciatus (Bl. and Sch.).

The testicular architecture of Colisa fasciatus was studied after 15 and 30 days of exposure to 14.0 or 2.0 mg/l arsenic(III) oxide. Marked alterations occurred at 14.0 mg/l after 30 days of treatment, while 2.0 mg/l (the concentration in Lake Chilwa) produced little change. In addition to the degenerative changes in the lobules, the interstitial Leydig cells (steroid-secreting cells) underwent significant reduction (P less than 0.01) in diameter. Varying degrees of necrosis and pyknosis suggested reduced secretory levels. Such changes may be correlated with the corresponding altered spermatogenesis.

Animals↗
PubMed1984

Atrial natriuretic factor: purification of active peptides, cloning of cDNA and determination of structures of active peptides and precursors.

Four peptides possessing both natriuretic and smooth muscle relaxant activities were purified from rat heart atrium and their amino acid sequences were determined. All contained a common sequence which contains a macro-ring structure formed by 17 amino acid residues and a disulphide bridge. The major atrial peptide in the atrium was identified as that containing 31 amino acid residues. The cDNA of the atrial peptide precursor was cloned and its nucleotide sequence determined. The amino acid sequence of the precursor deduced from the nucleotide sequence contained 152 residues and a potential signal peptide sequence characteristic of secretory polypeptides.

Amino Acid Sequence↗
PubMed1984

Correlative changes in the Leydig's cells and male secondary sexual characters (SSC) in a freshwater fish Mystus (M) vittatus.

The study of testicular steroidogenic tissue in the freshwater fish Mystus (M) vittatus has been made by employing histochemical techniques to localize lipids. The Leydig's cells are steroidogenic. Their functional significance has been correlated with secondary sexual characters (SSC). The SSC have been found to follow a clear cut testicular cycle. The development of SSC is reflected by the abundance, numerical variations, size difference, hypertrophy and hyperplasia of the interstitial Leydig's cells. Functional identity of Sertoli cells in the development of SSC seems doubtful.

Animals↗
PubMed1983

Respiratory functions in thermal burns.

In our present series, respiratory functions were observed in patients with a relatively small extent of burn compared to that commonly represented by the published works, and for a considerable duration of time (three weeks), commencing soon after the burn trauma. Respiratory rate increased in the post burn trauma and the peak expiratory rate was observed on the 8th post burn days and then it gradually fell but still remaining much higher than the control normal value. The minute volume and tidal volume also showed similar rise on the 8th post burn day and then gradually fell to below the mean level of 3rd post burn day before the 3rd post burn week. Forced vital capacity, forced expiratory volume in one second, forced expiratory volume in three seconds, forced expiratory volume in one second as a percentage of forced vital capacity, forced expiratory volume in three seconds, as a percentage of forced vital capacity and peak expiratory flow rates, did not vary much and indicated no significant respiratory abnormality.

Burns↗
PubMed1983

Blood gas studies in thermal burns.

In the present study we have included 25 cases with a relatively small extent of burns as compared to those described in many of the other published work. We have chosen the 3rd post-burn day as the day of reference (because most of the patients did not turn up before that day) from which day onwards adequate number of observations were available. Arterial blood gas studies revealed significant decrease in arterial partial pressure oxygen on 5th and 8th post-burn days with lowest mean value on 8th post burn day and then a gradual rise towards the normal value. Arterial partial pressure of carbon dioxide fell after the burn to reach the lowest value on the 5th post burn day and then returned towards the normal value. Arterial hydrogen ion concentration also fell (i.e. arterial blood pH rise) in the post-burn course. This was significant on the 11th post burn day.

Adult↗