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Biomedical subjects

S Banerjee

Publications and source records attributed to S Banerjee.

At least 91 records · Page 5Linked to original sources
PubMed2001

Rectourinary fistula with a narrow urethra.

A rectourinary fistula is a common accompaniment of anorectal malformations (ARM) in boys. Most boys pass urine normally after reconstruction and closure of the fistula, but a few have serious problems because of a narrow urethra. In our series, a narrow urethra was encountered in three types of male ARM: 3 rectourethral fistulae, 4 rectovesical fistulae, and 6 H-fistulae. We have studied the diagnostic and therapeutic problems that a narrow urethra produces in patients afflicted with each of these malformations.

Abnormalities, Multiple↗
PubMed2001

Reproductive outcomes in women with congenital uterine anomalies detected by three-dimensional ultrasound screening.

OBJECTIVE: To determine reproductive outcomes in women with congenital uterine anomalies detected incidentally by three-dimensional ultrasound. METHODS: We studied 1089 women with no history of infertility or recurrent miscarriage who were seen for a transvaginal ultrasound scan. They were screened for uterine abnormalities using three-dimensional ultrasound. We determined prevalence of miscarriage and preterm labor in women with normal and abnormal uterine morphology. RESULTS: We found that 983 women had a normally shaped uterine cavity, 72 an arcuate, 29 a subseptate, and five a bicornuate uterus. Women with a subseptate uterus had a significantly higher proportion of first-trimester loss (Zeta = 4.68, P <.01) compared with women with a normal uterus. Women with an arcuate uterus had a significantly greater proportion of second-trimester loss (Zeta = 5.76, P <.01) and preterm labor (Zeta = 4.1, P <.01). There were no other significant differences in pregnancy outcomes between women with normal and abnormal uterine morphology. CONCLUSION: This study shows the potential value of three-dimensional ultrasound and confirmed that women with congenital uterine anomalies were more likely to have adverse pregnancy outcomes than women with a normal uterus.

Abortion, Habitual↗
PubMed2001

Triterpenoid saponins from Mollugo spergula.

Two novel triterpenoid saponins belonging to a modified hopane group, spergulin A [3-O-(beta-D-xylopyranosyl 4-sulphate)-spergulagenin A] (1) and spergulin B [3-O-[alpha-rhamnopyranosyl (1-->2)-beta-D-xylopyranosyl]-spergulatriol] (4) were isolated from the aerial part of Mollugo spergula along with spergulacin (2) and spergulacin A (3). Their structures and relative stereochemistry were determined by a combination of 2D-NMR (COSY, TOCSY, HETCOR, NOESY and HMBC) and HR-FAB-MS analysis coupled with strategic chemical and enzymatic transformations.

Magnetic Resonance Spectroscopy↗
PubMed2001

Studies into abstract properties of individuals. VI. The degree of emergence in individuals, populations, species and a three species lineage.

Emergent properties derived from the integration among descriptive variables were explored in three related grass species, Achnatherum lemmonii, Achnatherum hendersonii and Achnatherum wallowaensis. Different levels of organization were compared: individuals, populations, species, species-pairs and all three species combined. Emergence was seen at all levels with populations having the lowest degree followed by individuals, species and combinations of species. Because there were no variables unique to any level analyzed, emergence is more than the appearance of new structures. As the degree of emergence increases there is also an increase in variation in integration, the result of new growth rates. Time may explain the different degrees of emergence at the different levels. The trend populations-species-combination of species is easily related to time; the first are younger than the last. An individual develops over a greater period of time than a population. The greater time of existence of a species may account for a greater degree of emergence than an individual. In an individual the local time expressed during ontogeny establishes boundary conditions for an individual. As that local time becomes incorporated into global, or phylogenetic, time, the boundary conditions for taxa and lineages is established.

Phylogeny↗
PubMed2001

Spatial regulation of DELTA expression mediates NOTCH signalling for segmentation of Drosophila legs.

The Notch (N) signalling pathway is recruited for segregation of cell fates in a number of Drosophila tissue types. We show here that N dependent segmentation of Drosophila legs is regulated by a dynamic pattern of expression of its ligand, DELTA (DL). During third larval instar and early stages of pupation, high levels of DL expression is seen in stripes of cells in the leg imaginal discs which later form the proximal borders of leg joints. These domains also displayed heightened Dl enhancer activity. During subsequent stages of pupation, following segmentation of the leg primordium, DL expression becomes uniform throughout these segments barring the joints. We further show that regulatory Dl mutations or mis-expression of DL abolish leg segmentation. Domains of N signalling for segmentation of legs of flies are thus set up by a stringent spatial regulation of expression of its ligand at the segment border. Further, a comparable role of DL in antennal development reveals a common paradigm of DL-N signalling for segmentation of appendages in flies.

Animals↗
PubMed2001

Tc-99m and Re-186 complexes of tetraphosphonate ligands and their biodistribution pattern in animal models.

The syntheses of four alpha-aminomethyl phosphonates and their complexation studies with (99m)Tc and (186/188)Re are reported. Complexation conditions were standardized to give maximum yields, which ranged from 90-97%. The yields of complexation were estimated by paper chromatography. The (99m)Tc complexes were stable for more than 4 h, while the (186/188)Re complexes were stable for 3-8 days when stored at 4 degrees C. Biodistribution of these complexes in Wistar rats were carried out, and the uptake in bone and other soft tissue are detailed. Bone uptake of the (99m)Tc complexes varied from 40-60% at 30 min postinjection depending on the ligands. The uptake in soft tissue was minimum with all the complexes. A comparison of the biodistribution studies of the (99m)Tc complexes with that of the well-established radiopharmaceutical (99m)Tc-MDP was carried out for the purpose of evaluating the efficacy of the radiopharmaceutical preparation with the complexes of these ligands. The bone uptake of the (186/188)Re complexes varied from 19-28% corresponding to 1.6-3% per g at 3 h postinjection. The residual activity in both (99m)Tc and (186/188)Re complexes showed renal clearance.

Animals↗
PubMed2001

Potential (166)Ho radiopharmaceuticals for intravascular radiation therapy (IVRT)-I: [(166)Ho] holmium labeled ethylene dicysteine.

The use of beta(-) emitting radionuclides in the control of restenosis in post angioplasty patients is currently under intense investigation at many leading cardiovascular research centers. (32)P coated metallic stents, (192)Ir wire source and balloons filled with an appropriate radionuclide solution such as of (188)Re, attached to catheter are being studied. (166)Ho has comparable radionuclidic properties to that of (188)Re, can be more easily produced and hence is an attractive alternative to (188)Re. Ethylene dicysteine complex of (166)Ho was prepared and its pharmacological behavior studied. Optimum conditions for the preparation of complex with respect to the reaction time, ligand concentration, pH of the reaction mixture as well as reaction temperature were standardized. The stability of the labeled complex at room temperature as well as at 4 degrees C was determined. Biodistribution pattern of the injected complex in Wistar rats was estimated at 10 min, 30 min and 3 h post injection. This study indicated that >90% of the injected (166)Ho-EC complex was excreted in urine within 3 h post injection, with insignificant retention in any major organ. These studies reveal that (166)Ho-EC could be a viable substitute for (188)Re compounds in radioactive liquid-filled balloon IVRT.

Animals↗
PubMed2001

186Re-1,4,8,11-tetraaza cyclotetradecyl-1,4,8,11-tetramethylene phosphonic acid: a novel agent for possible use in metastatic bone-pain palliation.

In connection with our work on the development of 186Re-tetra-phosphonates with optimum properties for use in bone pain palliation, a novel cyclic tetraphosphonate derivative, has been synthesized, complexed with 186Re and evaluated with promising results. The ligand, which consists of a cyclic array of tetra-aminomethylphosphonate groups, was synthesized using orthophosphorus acid, 1,4,8,11-tetraazacyclotetradecane and formaldehyde. The labeling conditions with 186Re have been standardized under varying reaction conditions to give maximum yield. In a reaction volume of 1 mL, maximum complexation yield of 98% was observed at pH 2 using 0.1 mg Re (37-370 MBq) for a ligand concentration at 9 x 10(-2) M/L, under heating at 100 degrees C for 30 min with 2 mg of stannous chloride. The complex was found to be stable for 6 days with RC purity remaining approximately 97%. The complex was characterized by paper chromatography in saline and acetone, wherein the R(f) exhibited were 0.9 and 0, respectively. Biodistribution studies of the complex were performed in male Wistar rats. Activity in femur which was observed to be 1.8%/g (equivalent to about 23% of the injected activity in skeleton) at 3 h post injection remained almost constant up to 48 h. Minimum activity was observed in blood and other soft tissues. The complex showed major renal clearance. Scintigraphic images in rabbits after injecting 70-100 MBq of 186Re-CTMP and using a dual head gamma camera were observed to be superior to 186Re-HEDP, prepared by a procedure standardized by us. Insignificant activity was observed in other vital organs. The results suggest the suitability of the complex for further evaluation in higher animals for bone pain palliation.

Analgesics↗
PubMed2001

Differential expression of WISP-1 and WISP-2 genes in normal and transformed human breast cell lines.

The transcriptional alterations of specific gene(s) are actively associated with the development of different cancers including breast. The preceding studies of different laboratories documented at least 40 genes that may contribute directly to the genesis of cancer. Using differential display, RT-PCR and DNA sequencing analyses in normal human mammary epithelial cells (HMEC) and various breast tumor cell lines including MCF-7, ZR-75, T-47D and SKBR2, we demonstrated that WISP-1 and WISP-2 genes are differentially transcribed in these cells. WISP-2 mRNA transcription was identified in all 4 tumor derived cell lines, but the mRNA expression was undetected or minimally detected in normal breast epithelial cells. WISP-1 mRNA expression was identified in normal and transformed cell lines. However, the level of expression was higher in different breast tumor cell lines as compared to HMEC. The mRNA expression profiles of WISP genes in normal breast epithelial cells and breast tumor derived cell lines indicated a strong possibility of the involvement of WISP-signaling in the development of human breast tumors, and can be utilized as genetic markers of this disease.

Base Sequence↗
PubMed2001

Adsorption, attachment and biofilm formation among isolates of Listeria monocytogenes using model conditions.

AIMS: To determine whether isolates of Listeria monocytogenes differ in their ability to adsorb and form biofilms on a food-grade stainless steel surface. METHODS AND RESULTS: Strains were assessed for their ability to adsorb to a test surface over a short time period. Although some differences in numbers of bound cells were found among the strains, there were no correlations between the degree of adsorption and either the serotype or source of the strain. The ability of each strain to form a biofilm when grown with the test surface was also assessed. With the exception of a single strain, all strains adhered as single cells and did not form biofilms. Significant differences in adherence levels were found among strains. Strains demonstrating enhanced attachment produced extracellular fibrils, whereas those which adhered poorly did not. A single strain formed a biofilm consisting of adhered single cells and aggregates of cells. CONCLUSIONS: Significant differences were found in the ability of various L. monocytogenes strains to attach to a test surface. In monoculture, the majority of strains did not form biofilms. SIGNIFICANCE AND IMPACT OF THE STUDY: Differences in attachment and biofilm formation among strains provide a basis to study these characteristics in L. monocytogenes.

Adsorption↗
PubMed2001

Evolution of Tc-99m in diagnostic radiopharmaceuticals.

The progress in diagnostic nuclear medicine over the years since the discovery of 99mTc is indeed phenomenal. Over 80% of the radiopharmaceuticals currently being used make use of this short-lived, metastable radionuclide, which has reigned as the workhorse of diagnostic nuclear medicine. The preeminence of 99mTc is attributable to its optimal nuclear properties of a short half-life and a gamma photon emission of 140 keV, which is suitable for high-efficiency detection and which results in low radiation exposure to the patient. 99mTcO4-, which is readily available as a column eluate from a 99Mo/99mTc generator, is reduced in the presence of chelating agents. The versatile chemistry of technetium emerging from the 8 possible oxidation states, along with a proper understanding of the structure-biologic activity relationship, has been exploited to yield a plethora of products meant for morphologic and functional imaging of different organs. This article reviews the evolution of 99mTc dating back to its discovery, the development of 99Mo/99mTc generators, and the efforts to exploit the diverse chemistry of the element to explore a spectrum of compounds for diagnostic imaging, planar, and single photon emission computed tomography. A brief outline of the 99mTc radiopharmaceuticals currently being used has been categorically presented according to the organs being imaged. Newer methods of labeling involving bifunctional chelating agents (which encompass the "3 + 1" ligand system, Tc(CO)3(+1)-containing chelates, hydrazinonicotinamide, water-soluble phosphines, and other Tc-carrying moieties) have added a new dimension for the preparation of novel technetium compounds. These developments in technetium chemistry have opened new avenues in the field of diagnostic imaging. These include fundamental aspects in the design and development of target-specific agents, including antibodies, peptides, steroids, and other small molecules that have specific receptor affinity.

Bone and Bones↗
PubMed2001

Differential diagnosis of intracavitary tumors obstructing the right ventricular outflow tract.

Three cases of right ventricular outflow tract obstruction caused by 3 distinct tumors-myxoma, sarcoma, and presumed metastatic tumor-diagnosed by transthoracic and transesophageal echocardiography are presented. The differences among these 3 types of tumors with similar clinical and echocardiographic findings are highlighted, and a review of the pertinent literature is discussed. By applying the approximate frequencies of cardiac tumors categorized by type and site, statistically, an intracavitary right ventricular outflow tract tumor is 70 to 140 times more likely to be malignant than benign; furthermore, if it is a primary cardiac tumor, it is approximately 2 times more likely to be a sarcoma than a myxoma.

Aged↗
PubMed2001

Hepatoprotective activity of Cassia fistula leaf extract.

Hepatoprotective activity of the n-heptane extract of Cassia fistula leaves was investigated by inducing hepatotoxicity with paracetamol in rats. The extract at a dose of 400 mg/kg body wt. exhibited orally, significant protective effect by lowering the serum levels of transaminases (SGOT and SGPT), bilirubin and alkaline phosphatase (ALP). The effects produced were comparable to that of a standard hepatoprotective agent.

Acetaminophen↗
PubMed2001

Recent advances in inflammatory bowel disease.

The last decade has seen tremendous advances in our knowledge, which has led to genuine improvements in our understanding of the pathogenesis and management of inflammatory bowel disease (IBD). The combined power of cellular and molecular biology has begun to unveil the enigmas of IBD, and, consequently, substantial gains have been made in the treatment of IBD. Refinements in drug formulation have provided the ability to target distinct sites of delivery, while enhancing the safety and efficacy of older agents. Simultaneous progress in biotechnology has fostered the development of new agents that strategically target pivotal processes in disease pathogenesis. This article addresses our current understanding of the pathogenesis of IBD, including the latest developments in animal models and covers agents currently used in the treatment of IBD as well as emerging therapies.

Animals↗
PubMed2001

A novel [186/188Re]-labelled porphyrin for targeted radiotherapy.

The concept of labelling a porphyrin, a tumour-avid agent, with a radionuclide to evaluate its potential as a therapeutic modality is reported. A novel water-soluble porphyrin, namely meso-tetrakis[3,4-bis(carboxymethyleneoxy)phenyl]porphyrin, with suitable dicarboxylic acid groups as aromatic substituents in the periphery, was synthesized and characterized. The labelling of this porphyrin with 186/188Re, a beta(-) emitter, was optimized by varying the reaction conditions. The complexation yield was >98% as estimated by paper chromatography in acetone and in saline. The radiochemical purity was found to remain at >98% when stored at 4 degrees C for 24 h. Biodistribution studies in Swiss mice bearing fibrosarcomas showed an uptake of approximately 3.5% per gram of tumour at 30 min post-injection. This uptake in the tumour was retained until 24 h post-injection with major activity showing renal clearance; no significant activity was present in other organs of interest. The tumour/blood and tumour/muscle ratios were observed to be 38 and 5, respectively, at 24 h post-injection, thereby indicating a possible therapeutic potential for tumours.

Animals↗
PubMed2001

The prevalence of Tourette syndrome in 13-14-year-olds in mainstream schools.

This study's aim was to estimate the prevalence and describe the clinical characteristics of Tourette syndrome (TS) in 13-14-year-old schoolchildren attending mainstream secondary schools. A three-stage ascertainment procedure was used to identify those who had TS. First, all 1012 Year 9 pupils were screened for tics using validated self-report questionnaires, which were completed by parents, teachers, and pupils. Data were available from at least one informant for 918 (90.7%) subjects. Tics were identified in 189 (18.7%) pupils. Second, families were contacted and a semistructured interview was carried out to determine whether they had TS. Finally, to ensure that the diagnosis of TS was correct, all those assessed as having TS were systematically assessed by an expert clinician in the field of TS. Seven young people were identified as fulfilling the criteria for TS, giving a minimum prevalence rate amongst 13-14-year-olds of 0.76% (95% CI 0.31 to 1.57) and a more realistic estimate of 1.85% (95% CI 1.00 to 2.95). Behavioural problems, in particular hyperkinetic disorder, were frequently associated with the TS group. These findings lend further support to the contention that the prevalence of TS in the community has hitherto been underestimated, though the symptoms may be generally milder than cases of TS presenting to clinics. This study supports the need for vigilance for TS in school-age children in primary care and in educational settings, so that children with this potentially serious disorder can be identified and assessed and effective management packages can be formulated to address their needs, when necessary.

Adolescent↗
PubMed2001

Expectant management of early pregnancies of unknown location: a prospective evaluation of methods to predict spontaneous resolution of pregnancy.

OBJECTIVE: To assess prospectively the ability of two multiparameter diagnostic models and their individual components to predict the outcome of early pregnancies which could not be identified on transvaginal ultrasound scan. DESIGN: Prospective observational study. SETTING: Dedicated early pregnancy unit in an inner city teaching hospital. POPULATION: Women with a positive urine pregnancy test and clinical suspicion of early pregnancy complications. METHODS: A full medical history, clinical examination and transvaginal ultrasound scan were carried out at the initial visit. When the location of the pregnancy could not be ascertained by ultrasound, serum beta-human chorionic gonadotrophin (beta-hCG) and progesterone levels were measured. All women were managed expectantly until either a normal pregnancy was visualised on scan; the pregnancy resolved spontaneously or intervention was required due to a worsening of clinical symptoms or non-declining beta-hCG levels. MAIN OUTCOME MEASURES: Spontaneous resolution of pregnancy (i.e. cessation of symptoms and decline in serum beta-hCG level to < 20 iu/L) without need for any active intervention. RESULTS: Of the 104 women recruited, 72 (69%) pregnancies resolved spontaneously. Both multiparameter diagnostic models identified resolving pregnancies with positive predictive values > or = 95%. Their performances were not significantly better compared with individual progesterone levels which achieved a positive predictive value of 97% using a cutoff level of 20 nmol/L. CONCLUSION: Serum progesterone measurement alone is as accurate as more complex diagnostic models for the prediction of successful expectant management in pregnancies of unknown location.

Abortion, Spontaneous↗