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Biomedical subjects

S Banerjee

Publications and source records attributed to S Banerjee.

At least 109 records · Page 6Linked to original sources

Observation of a narrow charmoniumlike state in exclusive B+/--->K+/-pi+pi-J/psi decays.

We report the observation of a narrow charmoniumlike state produced in the exclusive decay process B+/--->K+/-pi(+)pi(-)J/psi. This state, which decays into pi(+)pi(-)J/psi, has a mass of 3872.0+/-0.6(stat)+/-0.5(syst) MeV, a value that is very near the M(D0)+M(D(*0)) mass threshold. The results are based on an analysis of 152M B-Bmacr; events collected at the Upsilon(4S) resonance in the Belle detector at the KEKB collider. The signal has a statistical significance that is in excess of 10sigma.

Journal Article↗

Search for large extra dimensions in the monojet+E(T) channel with the DØ detector.

We present a search for large extra dimensions (ED) in pp collisions at a center-of-mass energy of 1.8 TeV using data collected by the DØ detector at the Fermilab Tevatron in 1994-1996. Data corresponding to 78.8+/-3.9 pb(-1) are examined for events with large missing transverse energy, one high-p(T) jet, and no isolated muons. There is no excess observed beyond expectation from the standard model, and we place lower limits on the fundamental Planck scale of 1.0 and 0.6 TeV for 2 and 7 ED, respectively.

Journal Article↗

Prediction of early pregnancy viability in the absence of an ultrasonically detectable embryo.

OBJECTIVE: To identify clinical, ultrasound and biochemical parameters that may allow prediction of pregnancy viability in women without a detectable embryo on ultrasound examination. METHODS: This was a prospective observational study of pregnant women with an ultrasound finding of a gestational sac measuring < 20 mm mean diameter without a visible embryo. Women's age, menstrual dates, clinical symptoms (pain and bleeding), mean gestational sac diameter and measurements of serum beta-human chorionic gonadotropin and progesterone were recorded in all cases. All women were managed expectantly until the pregnancy viability was established conclusively based on clinical and ultrasound findings. All parameters were tested by univariate analysis and then analyzed in a stepwise procedure to form a logistic regression model for predicting pregnancy viability. RESULTS: One hundred and eighteen (59%) women had a normal intrauterine pregnancy and 82 (41%) had a miscarriage. Stepwise analysis showed that three diagnostic parameters (maternal age, gestational sac diameter and serum progesterone) contributed significantly to the predictive power of the logistic model. With this model, at a cut-off value of 10% probability, the diagnosis of viable pregnancy was made with a sensitivity of 99.2% (95% CI, 95.8-99.97) and specificity of 70.7% (95% CI, 61.3-78.9). CONCLUSION: The use of a logistic regression model allows prediction of pregnancy viability when an embryo cannot be visualized on ultrasound scan.

Abortion, Spontaneous↗

Measles, mumps, rubella (MMR) vaccine.

MMR is a live attenuated vaccine. Indian children show almost 90% seroconversion against measles and rubella and 90% against mumps. Several adverse effects have been reported. Epidemiological studies do not support a causative link between MMR and autism, IBD or GBS. There is an association between the Urabe strain of mumps vaccine and viral meningitis. Vaccine associated thrombocytopenia has been reported. Severe hypersensitivity reactions occur, mainly due to the gelatin component. Outbreaks of measles occur in areas of high measles vaccine coverage, when susceptible individuals accumulate. A second dose is given mainly to vaccinate those who missed the first dose or had primary vaccine failure, rather than to boost waning antibody levels. The possibility or eradication of mumps with a second dose of mumps vaccine is being considered.

Autistic Disorder↗

Histone acetylation-mediated regulation of genes in leukaemic cells.

Histone deacetylase (HDAC) and histone acetyltransferase (HAT) functions are associated with various cancers, and the inhibition of HDAC has been found to arrest disease progression. Here, we have investigated the gene expression profiles of leukaemic cells in response to the HDAC inhibitor trichostatin A (TSA) using oligonucleotide microarrays. Nucleosomal histone acetylation was monitored in parallel and the expression profiles of selected genes were confirmed by quantitative polymerase chain reaction (PCR). A large number of genes (9% of the genome) were found to be similarly regulated in CCRF-CEM and HL-60 cells in response to TSA, and genes showing primary and secondary responses could be distinguished by temporal analysis of gene expression. A small fraction of genes were highly sensitive to histone hyper-acetylation, including XRCC1, HOXB6, CDK10, MYC, MYB, NMI and CBFA2T3 and many were trans-acting factors relevant to cancer. The most rapidly repressed gene was MKRN3, an imprinted gene involved in the Prader-Willi syndrome.

Acetylation↗

Prenatal exposure to high galactose adversely affects initial gonadal pool of germ cells in rats.

BACKGROUND: In rats, prenatal exposure to high concentrations of galactose may contribute to a condition that is equivalent to the premature ovarian failure (POF) component of human galactosaemia. We investigated if development of POF under experimental galactosaemia-like conditions was attributed to impaired germ cell migration. METHODS: Pregnant rats were fed pellets supplemented with, or without, 35% galactose from day 3 of conception continuing through parturition. Between days 12-15, embryos from one uterine horn were dissected out. Primordial germ cells (PGC) were histochemically localized and counted on the basis of binding of Dolichos biflorus agglutinin, a lectin specific for terminal N-acetylgalactosamine (GalNAc), to the surface glycoconjugate of the germ cells. The embryos from the other uterine horn were maintained until parturition. Liver activity of uridine diphosphate galactose 4-epimerase, the enzyme involved at multiple steps in the process of synthesis of GalNAc, was assayed in 1-2 day old female pups. RESULTS: The numbers of PGC at the day-specific sites on all days of examination were significantly lower (P </= 0.0003), and liver epimerase activity was significantly (P = 0.000001) reduced in the galactose-exposed group. CONCLUSION: Impaired germ cell migration leading to the development of gonads with deficient initial pools of germ cells may form the causal link between galactosaemia and POF.

Animals↗

Galactose toxicity in the rat as a model for premature ovarian failure: an experimental approach readdressed.

BACKGROUND: The pathophysiological mechanisms underlying premature ovarian failure (POF) are largely unknown. Our objective was to develop a working animal model to explore the pathogenesis of POF. Since galactosaemic women eventually develop POF, we evaluated the potential of experimental galactose toxicity as the proposed model. METHODS: Pregnant rats were fed pellets supplemented with or without 35% galactose from day 3 of conception continuing through weaning of the litters. Female offspring were evaluated for serum levels of galactose and galactose-1-phosphate, growth rate, onset of puberty, reproductive cyclicity, ovarian complement of follicles, hypothalamo-pituitary-ovarian function and follicular response to gonadotrophins. RESULTS: Galactose toxicity delayed the onset of puberty and developed a state of hypergonadotrophic hypoestrogenism. The characteristic low FSH levels at weaning followed by pubertal spurts of gonadotrophins and estradiol (E(2)) secretion of the controls was replaced by a sustained high level of FSH and a low level of E(2) under galactose toxicity. The ovary developed with apparently normal or deficient complement of follicles. Ovarian response to exogenous gonadotrophin stimulation was blunted, but the response improved significantly when the stimulation was preceded by pituitary desensitization. CONCLUSION: Experimental galactose toxicity may serve as a model for exploring some of the basic tenets of POF.

Aging↗

Mass photokeratitis following exposure to unprotected ultraviolet light.

We report a cluster of patients developing photokeratitis as a result of exposure to unprotected UV-B light source. The incident occurred at a cattle livestock market auction where the light source protective covers of mercury vapour lamps were damaged because of vandalism. The incident was investigated by the District Council as a public health and safety issue. This report stresses the hazards of ultraviolet lamps routinely used in public places and the need for proper maintenance of these light sources.

Cluster Analysis↗

Technetium-99m DTPA dimethyl ester: a renal function imaging agent. Comparative studies in animals with technetium-99m mercaptoacetyl triglycine and 131I-ortho-iodohippurate.

The dimethyl ester of diethylene triamine penta-acetic acid (DMDTPA) (I) can be easily and efficiently labelled with 99mTc. This method can be readily adapted for kit formulations to produce a highly stable and very pure chelate, as shown by paper electrophoresis and reverse-phase high performance liquid chromatography experiments. In mice, this chelate was excreted unchanged in the urine, and the amount of renal excretion was much higher than that of 99mTc-DTPA and comparable with that of 99mTc-mercaptoacetyl triglycine (99mTc-MAG(3)) at two different time points. The renal excretion of co-injected 131I-ortho-iodohippurate (131I-OIH), however, was significantly greater than that of the 99mTc chelates. The renal clearance values of 99mTc-DMDTPA and 99mTc-MAG(3) were also similar and exceeded the corresponding value for 99mTc-DTPA, but were only half that of the 131I-OIH value in the rat. The renograms for 99mTc-DMDTPA and 99mTc-MAG(3) showed overall similarity in a dog model. The diethyl ester (III) and monoethyl ester (II) of DTPA, after labelling with 99mTc, produced the same chelate, as shown by analytical results and biological data, indicating that one of the ester groups in the DTPA diester is dealkylated during the chelation procedure. To confirm this, two more ligands, diethylene triamine 1,4,7,7-tetra-acetic acid (IV) and diethylene triamine 1,4,7-triacetic acid (V), were synthesized, resembling DTPA monoalkyl ester (II) and dialkyl ester (I, III), respectively, in the arrangement of the donor atoms. Ligand IV but not ligand V, on 99mTc chelation, can generate the specific pharmacophore for renal tubular transport that is also present in the ester chelates 99mTc-I, 99mTc-II and 99mTc-III, as shown by their decreased renal excretion in mice pretreated with a renal tubular transport inhibitor such as probenecid.

Animals↗

Height screening at school: ineffective without high standards and adequate resources.

BACKGROUND: The Coventry Consensus in 1998 recommended a single height measurement of all children at school entry or around the age of 5 years and prompt referral of children with height <0.4th centile for further assessment, in order to identify undetected and treatable asymptomatic growth disorders. AIM: To determine adherence and practicalities of following the Coventry Consensus recommendations in a community setting and the cost implications. METHODS: Anthropometric data of all children born between September 1992 and August 1993 in the Rhondda and Taff Ely area and measured in school year September 1998 to August 1999 were obtained from the National Child Health System (NCHS) and analysed in July 2000. RESULTS: Only 1592 (67.6%) of 2354 eligible children had their height measured. The NCHS could only flag up height data <2nd centile. Only five of the 15 children with height <0.4th centile were referred initially. Height measurements were not transcribed onto centiles in 75% of the case notes reviewed. When initially recalled, six of the 15 eligible children failed to attend the referral clinic. No new growth disorder was identified in any of these children. A conservative estimate of the cost to the health authority was pound 14 550 (US23 300 dollars; 20 500 euro) per annum. CONCLUSION: The study shows poor coverage and compliance together with a lack of parental awareness that short stature could be a potential health problem even in asymptomatic children. For a low yield programme to be successful and cost effective at the national level, a near 100% coverage is required. Further training of professionals in growth measurement and interpretation along with a campaign to raise both public and professional awareness is needed.

Anthropometry↗

Development of organised conjunctival leucocyte aggregates after corneal transplantation in rats.

AIM: To investigate the development of lymphoid aggregates in the conjunctiva after corneal transplantation in rats. METHODS: LEW or PVG strain corneas were transplanted orthotopically to PVG rats. Cornea and conjunctiva were examined clinically for up to 42 days. Eyes were removed with attached conjunctiva on days 10 and 15 after transplantation (before and during rejection), together with normal eyes, fixed, paraffin embedded, and examined immunohistochemically. RESULTS: Clinically, the temporal half of the upper palpebral conjunctiva of recipients of 10/19 allografts and 1/10 isografts developed pronounced swelling, correlating with inflammation and rejection. Histologically, the swelling comprised leucocytic aggregates with an altered overlying epithelium. Aggregates contained granulocytes, macrophages, and cells expressing major histocompatibility complex (MHC) class II, CD4, and CD8, all more numerous in allograft associated conjunctiva. Class II+ cells were more abundant at the surface, whereas macrophages and T cells were more numerous in the deeper stroma. There were few B cells. There was greater CD54 expression by vascular endothelium in allograft associated aggregates. Cells expressing TNFalpha and IFNgamma but not IL1beta were present in stromal and superficial areas. CONCLUSIONS: Corneal transplantation in rats induces the development of organised conjunctival leucocytic aggregates in a fixed location that are significantly more pronounced in recipients of allografts compared with isografts and show characteristics of a Th1 type immune response. These aggregates have characteristics of conjunctiva associated lymphoid tissue and may be sites of presentation of graft antigens and lymphocyte proliferation at the ocular surface.

Animals↗

Predictors of institutionalisation in people with dementia.

OBJECTIVE: To identify what patient and carer characteristics influence transition into residential care for people with dementia. METHOD: Longitudinal study of a cohort of people with dementia and their carers in contact with old age psychiatric services in south London. RESULTS: 100 people with dementia and their main family carer were recruited. At six month follow up 22 were in residential care, 63 in the community, 8 had died, and for 7 there were missing data. Between six and 12 months, 7 of the 63 in the community went into residential care, 4 died, and 12 were lost to follow up. The most striking finding is the 20-fold protective effect of having a co-resident carer (odds ratio 0.05, 95% confidence intervals 0.01 to 0.42, p=0.006). Higher ratings of behavioural problems in the person with dementia were also statistically significantly associated with transition into residential care as was the psychological domain of quality of life of the carer. CONCLUSION: These findings powerfully illustrate the pivotal role carried out by carers of people with dementia; interventions directly targeted at helping them to maintain this role would be supported by these data. These data also suggest that strategies directed at improving carer quality of life and at the resolution of behavioural disorder in the person with dementia may also have particular value.

Adult↗

Telesurveillance of elderly patients by use of passive infra-red sensors in a 'smart' room.

We have developed an automated surveillance system based on passive infra-red sensors. Eight sensors were installed in a hospital room. A computer automatically captured data from the sensors every night from 21:00 until 06:00 the following morning. The sensors were polled twice per second and when a sensor was activated by movement, the event and time were recorded in a data file. At the end of the surveillance period the program analysed the data and generated a report showing the activities taking place in the room and their times. Four elderly patients were observed for a total of 97 nights. A total of 1637 possible sequences of movements by the patient and the hospital staff were detected. The computer was able to identify 1450 sequences (89%) correctly, in comparison with manual analysis. Only 10 movements (0.6%) were undetected by the system; all were very short sequences (five or six activations of the sensors). The system was generally capable of detecting and classifying all major movements in the room.

Aged↗

Isolation and characterisation of in vivo released 41 kDa mycobacterial antigen in pulmonary and bone and joint tuberculosis and its identification with H37Ra in vitro released antigen.

OBJECTIVE: To isolate and characterise in vivo released 41 kDa mycobacterial antigen in pulmonary and bone and joint tuberculosis (TB) and its identification with in vitro released ES-41 kDa antigen. DESIGN: Circulating antigen was isolated from confirmed pulmonary tuberculosis serum (PTS) and bone and joint tuberculosis serum (BJS) by trichloroacetic acid precipitation and further fractionation by fast-protein liquid chromatography (FPLC). RESULTS: Fractionation of PTS and BJS by gel filtration column gave six protein fractions each. PTS-G3 and BJS-G3 showed maximum antigenic activity with ELISA. Further fractionation of PTS-G3 and BJS-G3 on cation exchange FPLC gave four different fractions each, of which BJS-G3B was seroreactive similarly to in vitro released 41 kDa antigen (ES-41) isolated from culture medium, whereas PTS-G3C was slightly less seroreactive. BJS-G3B could inhibit binding of in vitro released ES-41 to affinity purified antibodies in inhibition ELISA at lower concentrations than PTS-G3C (2 vs. 20 ng/ml), showing the identical nature of the antigens. Biochemical characterisation showed that circulating antigen PTS-G3C, BJS-G3B and in vitro released ES-41 antigen were lipoproteins in nature. CONCLUSION: This study helped to demonstrate the presence of 41 kDa antigen in the serum of pulmonary and bone and joint TB patients and its identification with H37Ra in vitro released 41 kDa antigen.

Antigen-Antibody Reactions↗

Tuberculosis of the gall bladder.

An unusual presentation of tuberculous involvement of gall bladder in the absence of clinically detectable tuberculosis elsewhere is described. Tuberculosis, a rare lesion in the gall bladder was seen in a case associated with chronic cholecystitis with acute exacerbation. This organ is supposed not to be involved by tuberculosis due to high concentration of bile-acids in pure bile. The mode of spread in the present case remains speculative.

Adult↗