Efficient gene trap screening for novel developmental genes using IRES beta geo vector and in vitro preselection.

We have used different gene trap vectors and in vitro preselection of embryonic stem (ES) cells for a large scale screening of insertional mutations in developmentally regulated genes. A gene trap vector was constructed, which contains an internal ribosome entry site (IRES) upstream from a betageo selectable-reporter fusion gene. Analysis of 801 independent integrations revealed that the IRESbetageo vector allows for a global enrichment of about 15 folds in the number of detectable gene trap events when compared with a conventional betageo vector.

Genes expressed after retinoic acid-mediated differentiation of embryoid bodies are likely to be expressed during embryo development.

In order to test if retinoic acid-mediated differentiation of embryoid bodies can be used as an in vitro preselection method for ES cell lines generated by gene trap, we correlated gene expression after in vitro differentiation and in 11.5-day embryos. Fifty-two genes captured by gene trap and expressed in undifferentiated embryonic stem cells were analyzed.

Gene trap expression and mutational analysis for genes involved in the development of the mammalian nervous system.

We have used a large-scale gene trap approach for the isolation and mutation of genes that might play roles in the developing nervous system. After in vitro integration of two different gene trap vectors (pGT1.8geo: Skarnes et al.

Follicular cells of the thyroid gland require Pax8 gene function.

The thyroid gland develops from two distinct embryonic lineages: follicular cells (which produce thyroxine) and parafollicular C-cells (which produce calcitonin) are of endodermal and neural crest origin, respectively. Little is known about the molecular mechanisms governing the generation of these different cell types. Mice lacking the transcription factor Ttf1 lack both cell types and thus are unable to develop a thyroid gland.

Breast feeding practices in a teaching hospital of Calcutta before and after the adoption of BFHI (Baby Friendly Hospital Initiative).

A comparative study has been made on two groups of 102 mothers each who delivered children in the postnatal ward of obstetrics and gynaecology department of Calcutta National Medical College before and after the introduction of BFHI (Baby Friendly Hospital Initiative). The study revealed that only 14.3% of the babies who were delivered normally were given their first breast feed in time, the ideal time of half an hour, while not a single baby delivered by caesarean section were given their breast feed within the stipulated time period of 4-6 hours.

Pax6 is required for differentiation of glucagon-producing alpha-cells in mouse pancreas.

The functional unit of the endocrine pancreas is the islet of Langerhans. Islets are nested within the exocrine tissue of the pancreas and are composed of alpha-, beta-, delta- and gamma-cells. beta-Cells produce insulin and form the core of the islet, whereas alpha-, delta- and gamma-cells are arranged at the periphery of the islet and secrete glucagon, somatostatin and a pancreatic polypeptide, respectively.

Evidence for the stochastic integration of gene trap vectors into the mouse germline.

A large scale insertional mutagenesis experiment was performed in embryonic stem (ES) cells by introducing two types of gene trap vectors into the genome. These cell lines carrying mutations were introduced into the mouse germline. In order to assess the feasibility of a large scale cloning of the targeted genes from these lines, we have isolated and characterized 55 trapped exons from the corresponding ES cells.

The Pax4 gene is essential for differentiation of insulin-producing beta cells in the mammalian pancreas.

The mammalian pancreas contains two distinct cell populations: endocrine cells which secrete hormones into the bloodstream, and exocrine cells, which secrete enzymes into the digestive tract. The four endocrine cell types found in the adult pancreas-(alpha, beta, delta and PP-synthesize glucagon, insulin, somatostatin and pancreatic polypeptide, respectively. All of these endocrine cells arise from common multipotent precursors, which coexpress several hormones when they start to differentiate.

An alpha-E-catenin gene trap mutation defines its function in preimplantation development.

Catenins are proteins associated with the cytoplasmic domain of cadherins, a family of transmembrane cell adhesion molecules. The cadherin-catenin adhesion system is involved in morphogenesis during development and in the maintenance of the integrity of different tissue types. Using a gene trap strategy, we have isolated a mouse mutation for the gene encoding the alpha-E-catenin.

Elucidation of the role of Arg 110 of murine leukemia virus reverse transcriptase in the catalytic mechanism: biochemical characterization of its mutant enzymes.

Based on the projected three-dimensional equivalence of conserved amino acids in the catalytic domains of DNA polymerases, we propose Arg 110 of MuLV RT to be an important participant in the catalytic mechanism of MuLV RT. In order to obtain evidence to support this proposition and to assess the functional importance of Arg 110, we carried out site directed mutagenesis of Arg 110 and replaced it with Lys, Ala, and Glu. The mutant enzymes were characterized with respect to their kinetic parameters, ability to bind template-primers, and the mode of DNA synthesis.

Diagnosis and treatment of intracranial complications of paranasal sinus infections.

Complications and local extension of paranasal sinus infections most often involve the orbit and periorbita. Because of the widespread use of antibiotics since World War II, intracranial extension of maxillofacial sinusitis is rarely seen today. Nevertheless, the clinician must be aware of the potential for these complications, because late recognition of this condition and delays in treatment can increase morbidity and mortality rates.

Segment-specific expression of the neuronatin gene during early hindbrain development.

The developing hindbrain is segmented in a series of repetitive bulges called neuromeres or rhombomeres. In the mouse, first molecular evidence for segmentation of the hindbrain came from rhombomeres 3- and 5-specific expression of the Krox-20 gene. The hindbrain segments are linked with the expression of different Hox genes which have a role in patterning the hindbrain and branchial region of the vertebrate head.

Development and evaluation of rapid monoclonal antibody-based coagglutination test for direct detection of Vibrio cholerae O139 synonym Bengal in stool samples.

A monoclonal antibody-based coagglutination test directly detected Vibrio cholerae O139 synonym Bengal in 83 of 120 watery diarrheal stool specimens; on culture, 90 samples were positive. Thus, with 92% sensitivity, 100% specificity, and 100% positive and 95% negative predictive values, the coagglutination test is a useful rapid test for V. cholerae O139.

Regulated expression of Brachyury(T), Nkx1.1 and Pax genes in embryoid bodies.

Embryonic stem cells (ES) can be exploited to analyze in vitro mechanisms of cellular differentiation. We have utilized ES-derived embryoid body formation in an attempt to study cell types resulting from in vitro differentiation. To this end, a variety of molecular markers, preferably those which have been associated with regulatory events during mouse embryogenesis, was employed.

Plasma LH and FSH levels in azoospermia and in normal male and female human subjects.

Immunoassay of human plasma LH and FSH level was carried out in the Institute of Nuclear Medicine, Bangladesh. Apparently normal male and female volunteers and subjects having primary sterility were studied. Plasma LH and FSH levels of normal males ranged from 1.

Glutamate induces the growth factors NGF, bFGF, the receptor FGF-R1 and c-fos mRNA expression in rat astrocyte culture.

The effect of glutamate on primary cultures of rat cortical astrocytes was studied using Northern blot hybridization. Incubation with glutamate (100 microM, 15 min) induced nerve growth factor (NGF), basic fibroblast growth factor (bFGF), FGF receptor (FGF-R1) and proto-oncogene c-fos gene expression in a time dependent manner. Maximal induction of NGF, bFGF and FGF-R1 mRNA was reached after 4 h of incubation (7.

The ubiquitous transactivator Zfp-38 is upregulated during spermatogenesis with differential transcription.

We describe the complete nucleotide sequence of a full length cDNA clone encoding a new mouse zinc finger protein gene, Zfp-38 and localize it on chromosome 5 by the interspecific backcross analysis. The N-terminal domain of the Zfp-38 protein (64 kDa) contains 358 amino acids and the C-terminal domain of 197 residues encodes 7 zinc fingers. We also present evidence that Zfp-38 is a strong transcriptional activator.

Classification and treatment of zygomatic fractures: a review of 1,025 cases.

The treatment of zygomatic fractures varies among surgeons, and the cosmetic and functional results are frequently less than optimal. A treatment guideline based on a simple classification of zygomatic fractures is presented. The emphasis is placed on the indications for closed and open reduction, consistent methods of three-dimensional alignment and fixation, and the management of concomitant infraorbital rim and orbital floor fractures.

Free radicals induce gene expression of NGF and bFGF in rat astrocyte culture.

Hydrogen peroxide (H2O2) is a type of active oxygen species produced mainly in blood by inflammation, ischemia or anoxia. Treatment of rat neonatal cortical astrocytes in culture with 0.2-1.

Prevalence of thumb sucking in children of Calcutta.

The prevalence study of thumb digital sucking carried out on 3-12-year- old 2517 children, 1293 boys & 1224 girls, with different socio-economic status, belonging to villages, suburbs and city areas of Calcutta revealed that non-nutritional sucking habit was predominantly seen in cities, and bottle feeding was found to be the main cause of this habit; in 3-6-year-old children the prevalence of the habit was more in boys than girls but it persisted more in boys with increase in age.

Treatment of 813 zygoma-lateral orbital complex fractures. New aspects.

A 10-year experience with surgical treatment of 813 zygomalateral orbital complex fractures is reviewed. Regardless of the type or severity of the fracture pattern, concomitant fractures of the orbital floor and rim were approached exclusively through the transconjunctival approach without a lateral canthotomy. The advantages of this approach compared with the subciliary access are the avoidance of a visible scar and markedly reduced incidence of postoperative lower eyelid complications such as ectropion and edema.