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S Sen

Publications and source records attributed to S Sen.

At least 145 records · Page 8Linked to original sources
PubMed1998

Identification of antibodies directed against O-acetylated sialic acids in visceral leishmaniasis: its diagnostic and prognostic role.

A significantly increased O-acetylated sialic acid (O-AcSA) binding fraction was purified from serum of visceral leishmaniasis (VL) patients by affinity chromatography on immobilized bovine submaxillary mucin (BSM) and found to be immunoglobulin in origin. The serodiagnostic and prognostic potential of BSM as a capture antigen was established by ELISA with no cross reactivity with coendemic diseases like malaria, tuberculosis, leprosy, chagas disease and cutaneous leishmaniasis; however, a strong cross reactivity was present with trypanosomiasis patients. In 56 clinically diagnosed VL patients, the BSM-ELISA was compared with diagnosis by microscopy using Giemsa stained tissue smears and direct ELISA using crude parasite antigen (parasite-ELISA); 49/56(87.5%) and 5/56(9.0%) were positive and negative respectively by all 3 methods. The BSM-ELISA failed to diagnose 2/56(3.5%) patients which were biopsy and parasite-ELISA positive. The prognostic potential of the BSM-ELISA in 18 longitudinally monitored VL patients before and after conventional antimonial treatment showed a significant decrease in anti O-AcSA titres in drug responsive patients whereas anti O-AcSA levels persisted in drug unresponsive patients. The IgG subclass distribution of antibodies directed against O-AcSA showed increased IgG2 levels in VL patients as compared to healthy controls. The BSM-based ELISA holds great promise as a serodiagnostic and prognostic assay for VL.

Acetylation↗
PubMed1998

Tumour amplified kinase STK15/BTAK induces centrosome amplification, aneuploidy and transformation.

The centrosomes are thought to maintain genomic stability through the establishment of bipolar spindles during cell division, ensuring equal segregation of replicated chromosomes to two daughter cells. Deregulated duplication and distribution of centrosomes have been implicated in chromosome segregation abnormalities, leading to aneuploidy seen in many cancer cell types. Here, we report that STK15 (also known as BTAK and aurora2), encoding a centrosome-associated kinase, is amplified and overexpressed in multiple human tumour cell types, and is involved in the induction of centrosome duplication-distribution abnormalities and aneuploidy in mammalian cells. STK15 amplification has been previously detected in breast tumour cell lines and in colon tumours; here, we report its amplification in approximately 12% of primary breast tumours, as well as in breast, ovarian, colon, prostate, neuroblastoma and cervical cancer cell lines. Additionally, high expression of STK15 mRNA was detected in tumour cell lines without evidence of gene amplification. Ectopic expression of STK15 in mouse NIH 3T3 cells led to the appearance of abnormal centrosome number (amplification) and transformation in vitro. Finally, overexpression of STK15 in near diploid human breast epithelial cells revealed similar centrosome abnormality, as well as induction of aneuploidy. These findings suggest that STK15 is a critical kinase-encoding gene, whose overexpression leads to centrosome amplification, chromosomal instability and transformation in mammalian cells.

Aneuploidy↗
PubMed1998

Effect of Quillaja saponaria saponins and Yucca schidigera plant extract on growth of Escherichia coli.

Escherichia coli K-12 was exposed to Quillaja saponaria saponins from various commercial firms (Sigma, Roth and Nor-feed) and to an extract of Yucca schidigera plant powder (DK Sarsaponin 30) at different concentrations (0.05-1.0% w/v). A concentration-dependent response was observed. Quillaja saponaria saponins from Sigma increased growth up to 0.1% (w/v) level, whereas Nor-feed and Roth saponins produced maximum growth at a much higher level (0.5 and 0.75%, w/v, respectively). These results suggest that quillaja saponins from various sources differ in their biological activity, although all three saponins had the same content of vanillin-sulphuric acid reactive moieties. The lyophilized water extract from the DK Sarsaponin powder showed maximum growth at 0.1% (w/v) level. The levels at which maximum growth was observed did not change on subjecting the quillaja or yucca saponins to heat treatment in an autoclave (121 degrees C for 30 min). All the saponins and the plant extract increased growth of Escherichia coli up to a certain concentration and thereafter decreased growth. In spite of the decreased growth at higher levels of saponins, it was higher compared to the control (without saponin) up to levels of 1% (w/v) for all saponins except Quillaja saponins from Sigma, for which the growth was lower at levels of 0.25% (w/v) and higher. Saponins have the potential to modulate microbial growth in natural and artificial fermenters.

Anti-Bacterial Agents↗
PubMed1998

Buckling of redundant expansile stent distal to an oesophageal cancer: endoscopic management.

This report describes a complication that occurred as a result of deploying an Ultraflex stent too low in relation to a stenosing carcinoma of the gastro-oesophageal junction. Intermittent kinking of the redundant lower end of the stent caused frequent episodes of total dysphagia. A percutaneous endoscopic gastrostomy was deployed to anchor the redundant portion of the stent within the stomach, allowing it to be shortened with endoscopic stitch cutters. This procedure relieved the episodic dysphagia, and was well tolerated.

Adenocarcinoma↗
PubMed1998

IFN-beta partially counteracts inhibition of natural killer activity induced by some antitumor agents.

We investigated whether recombinant human (rHu-IFN-beta) (IFN-beta) could counteract the inhibition of natural killer (NK) activity caused by antitumor agents. Peripheral blood lymphocytes (PBL) were incubated with different antitumor agents alone or in combination with IFN-beta for 3 days and then tested in a cytotoxicity assay against the K562 cell line. The following drugs were used, all of which caused a dose-dependent inhibition of NK activity: etoposide, camptothecin, doxorubicin, cis-DDP, tallimustine, and L-PAM. Concomitant treatment with (1000 U/ml) IFN-beta counteracted the inhibitory effect of etoposide and camptothecin but had no consistent effect on the inhibition mediated by the other drugs. Mean values of inhibition of NK activity at 1 microM camptothecin was 48%+/-3.4% and with IFN-beta was 10%+/-4.9%. With 100 microM etoposide, mean value of inhibition was 78%+/-3.3%, and with IFN-beta, it was 18%+/-1.5%. Cell viability, assessed by vital dye exclusion, and drug uptake, assessed with radiolabeled etoposide, were similar in cells treated with or without IFN-beta. The protective effect of IFN-beta on NK function was rather selective, as IFN-beta did not counteract the drug-mediated inhibition of PBL proliferation when stimulated by phytohemagglutinin (PHA). Other cytokines, IFN-alpha, IFN-gamma, and interleukin-2 (IL-2), had similar protective effect, although IFN-beta, was slightly more potent. On the other hand, IL-6, a cytokine sharing some properties with IFNs was ineffective. Camptothecin inhibited the expression of mRNA for granzyme B, a lytic protein involved in lymphoid-mediated cytotoxicity. Combined treatment with IFN-beta restored-at least in part-the transcription of granzyme B mRNA. These results show that the immunosuppressive effect of some antitumor agents could be partly counteracted by treatment with IFN-beta.

Antineoplastic Agents↗
PubMed1998

Cardiac disorders and stroke.

Cardiac disorders are increasingly recognised as an important source of cerebral embolism. Atrial fibrillation is the most common cardiac dysrrhythmia that can predispose to stroke. Recent advances have significantly increased the identification of clinical, hematological and echocardiographic risk factors that predict the occurrence of atrial fibrillation related stroke. Also, clinical risk stratification has been used to determine medical therapy (aspirin or warfarin) for prevention of atrial fibrillation related brain embolization. Among the various structural heart diseases causing stroke, the role of patent foramen ovale remains controversial. Strides have been made in the use of ultrasonographic techniques such as transesophageal echocardiography and contrast transcranial doppler to detect patent foramen ovale. Coronary artery bypass grafting is often performed in patients with concomitant aortic atheroma and carotid stenosis that may predispose to stroke in the perioperative period. It is now possible to identify perioperatively significant aortic atherosclerosis (using transesophageal echocardiography and aortic ultrasound) and significant carotid disease (using carotid ultrasound) and make appropriate modifications in surgical technique to reduce the incidence of coronary artery bypass grafting related stroke. Because of shared risk factors it is not surprising that coronary artery disease is frequently found in stroke patients. Recent studies suggest that more than one-third of stroke patients have asymptomatic coronary artery disease. Conversely, the brain damaged by infarction may itself be responsible for the production of cardiac structural and electrical abnormalities. Both these factors may contribute to the finding that cardiac events are the leading cause of death in stroke patients on long term follow-up. Recognition of these correlations has enhanced our ability to treat and prevent stroke related mortality.

Animals↗
PubMed1998

The Mitrofanoff procedure in paediatric urinary tract reconstruction.

BACKGROUND: Urinary tract reconstruction is required in many congenital and some acquired urological conditions in childhood. The majority are managed by clean intermittent catheterization (CIC), for which purpose the appendix or other tubular structure may be used to provide a continent catheterizable abdominal stoma. METHODS: Between 1991 and 1996, 23 children underwent urinary tract reconstruction of varying complexity together with a continent diversion according to the Mitrofanoff principle. The appendix was used in 14 patients and the ureter in seven. Two patients had previously had an appendicectomy and the ureters were not suitable. One had a catheterizable channel made from an isolated segment of colon and the other had a detrusor tube constructed. RESULTS: Twelve patients with an appendix conduit, six with a ureteric conduit, and one with a colonic tube are continent, although the latter has had some problems with stomal stenosis. All manage CIC with comfort, the older children doing the procedure themselves. One appendix conduit has stomal incontinence and another was inadvertently divided during renal transplantation. The detrusor tube strictured and was removed. CONCLUSIONS: A continent abdominal stoma using the Mitrofanoff principle gives reliable results in children and is well tolerated. It should be considered in the management of children undergoing urinary tract reconstruction when CIC is necessary. The appendix is eminently suitable for this purpose but the ureter provides a satisfactory alternative in selected cases. When neither is available, alternative techniques for constructing a catheterizable continent channel may be considered.

Adolescent↗
PubMed1998

Tandem ureterocystoplasty.

BACKGROUND: Bladder augmentation may be undertaken by using various gastrointestinal segments but their use is associated with a multitude of well-recognized complications. The mega-ureter has proven to be a satisfactory alternative; in patients with bilateral mega-ureters, both ureters may be used for this purpose. METHODS: Seventeen patients had augmentation ureterocystoplasty, including three in whom both distal ureters were used in tandem. The latter included two patients with neurogenic bladder and one with bladder exstrophy. RESULTS: Satisfactory augmentation was achieved in all patients undergoing tandem ureterocystoplasty. The neurogenic bladder patients are managed by urethral clean intermittent catheterization (CIC) and the exstrophy patient is managed by CIC of an appendicovesicostomy (Mitrofanoff). All are continent. CONCLUSIONS: The mega-ureter provides an excellent source of augmentation material in patients with small non-compliant bladders. In those with bilateral mega-ureters, consideration should be given to using both ureters in tandem to achieve the maximum possible bladder capacity.

Bladder Exstrophy↗
PubMed1998

Construction of continent catheterizable urinary conduit from an isolated segment of colon.

BACKGROUND: Continent urinary diversion may be necessary in a range of urological abnormalities. In circumstances where the standard techniques are not possible, alternative innovative techniques may be used. METHODS: In a female patient with bladder exstrophy, a continent diversion was recommended. The appendix was not available, the ureters were not suitable and a continent stoma was fashioned from an isolated segment of colon. RESULTS: The stoma proved to be continent, although it was somewhat stenotic. However, clean intermittent catheterization maintained its patency. CONCLUSIONS: A continent catheterizable stoma may be constructed from a segment of colon. The technique may be considered when other well recognized methods are not feasible.

Bladder Exstrophy↗
PubMed1998

Rapid diagnosis of Indian visceral leishmaniasis using achatininH, a 9-O-acetylated sialic acid binding lectin.

We have developed a rapid, accurate, and inexpensive hemagglutination assay (HA) for diagnosis of Indian visceral leishmaniasis (VL) using achatininH, a 9-O-acetylated sialic acid binding lectin. The assay is based on the selective binding of achatininH to 9-O-acetylated derivatives of sialic acid (9-O-AcSA), which appears exclusively on the erythrocytes of patients with VL. Blood samples from 35 patients with demonstrable splenic or bone marrow amastigotes were assayed by HA and compared with an ELISA. All cases were correctly diagnosed by HA, and were in concordance with the ELISA. The increase in 9-O-AcSA was corroborated by direct fluorimetric estimation of sialic acid and its 9-O-acetylated derivative. Therefore, 9-O-acetylated derivatives of sialic acid, absent in normal erythrocytes, serve as an important biomarker, and indirectly reflect the presence of the parasite. Accordingly, this assay can be used for detection of active kala-azar cases and merits clinical consideration.

Biomarkers↗
PubMed1998

Hepatitis E virus infection in eastern India.

Most cases of enterically transmitted non-A, non-B hepatitis in India have so far been attributed to hepatitis E virus (HEV) infection. Most of the documented studies of hepatitis have focused on the incidence of this disease in northern, western, and south central India. A small seroprevalence study was conducted in the eastern Indian city of Patna to assess the degree of HEV infection among acute sporadic hepatitis cases. Forty-two percent (24 of 57) of the cases of acute sporadic hepatitis were positive for anti-HEV antibodies. Absence of any serologic markers of hepatitis A, B, or E in 58% (33 of 57) of the cases with symptoms of acute hepatitis suggest that there may be as yet unidentified enterically transmitted viruses in this area.

Adult↗
PubMed1998

Beta-thalassaemia mutations in northern India (Delhi).

The present study was undertaken to define beta-thalassaemia mutations prevalent in northern India (Delhi). Forty six children of beta-thalassaemia major and their families were investigated. DNA was extracted from leucocytes and screened for mutations prevalent in the Indian population. These mutations included 619bp deletion, IVS 1-1 (G-T), IVS 1-5 (G-C), frameshift mutations FS 8/9 (+G), FS 41/42 (-CTTT), Codon 16(-C), Codon 15 (G-A), codon 30 (G-C), IVS 1-110 (G-A) and -88 (C-T). 619 bp deletion mutation was detected directly by amplification of DNA by PCR followed by agarose gel electrophoresis. Other mutations were studied by DNA amplification and dot blot hybridization using synthetic normal and mutant oligonucleotide probes labelled at 5' end with gamma-32 P-ATP. Five mutations accounted for all the chromosomes in 46 patients. 619 bp deletion mutation was found to be the commonest mutation (34.8%) followed by IVS 1-5 (G-C) in 22.8 per cent, IVS 1-1 (G-T) in 19.6 per cent, FS 8/9 (+G) in 13 per cent and FS 41/42 (-CTTT) in 9.8 per cent. Nineteen (41.3%) patients were homozygous and 27 (58.7%) double heterozygous for different beta-thalassaemia mutations. This observation of limited number of mutations is significant and will be useful in planning strategies for prenatal diagnosis of beta-thalassaemia in northern India.

Humans↗
PubMed1998

[A case of solitary retroperitoneal neurofibroma].

A 70-year-old woman was admitted to our hospital complaining of epigastralgia. Computed tomography, ultrasonography and magnetic resonance imaging revealed a round tumor measuring 6 cm in diameter, which was located in the medial side of the right kidney. It was successfully removed without injury to the surrounding large vessels and organs. Histological diagnosis was benign neurofibroma. This is the 27th case of solitary retroperitoneal neurofibroma reported in Japan.

Aged↗
PubMed1998

Achalasia cardia in infancy and childhood: an Indian experience.

Seven children with achalasia cardia, six of them infants, were seen over a 10-year period. In infantile achalasia, respiratory symptoms predominate and vomiting may easily be mistaken for gastroesophageal reflux (GER). Vomiting of uncurdled milk is characteristic of achalasia. Six children underwent esophagocardiomyotomy with good results in five. The procedure was transthoracic in two and transabdominal combined with an anterior fundoplication in the others. There was one post-operative death. Achalasia and alacrima were associated in two infants. One baby with this association also had a neurogenic bladder.

Child, Preschool↗
PubMed1998

An outbreak of Salmonella enteritidis phage type 5a infection in a residential home for elderly people.

The first outbreak of Salmonella enteritidis phage type (PT) 5a infection to be reported occurred after a party in a residential home for elderly people in May 1995. The party was attended attended by 96 residents, staff and guests. S. enteritidis PT5a was isolated from 14 of the 25 clinical cases identified after the party and S. enteritidis PT4 from another clinical case. Two elderly residents with S. enteritidis PT5a infection died. Infection with S. enteritidis PT5a was associated with consumption of prawn in mayonnaise vol-au-vents, sausage rolls, corned beef sandwiches, and sausages. The investigation of this outbreak illustrated the difficulty that elderly people may have in the completion of questionnaires. It also highlighted areas for intervention; such as reminders about basic hygiene precautions to prevent secondary spread and the importance of coordinated reinforcement in the workplace of formal food hygiene training for cooks. The Food Safety Regulations 1995 came into force soon after this outbreak: their implementation would probably have prevented it.

Adolescent↗