Deletion of the p27Kip1 gene restores normal development in cyclin D1-deficient mice

D-type cyclins (cyclins D1, D2, and D3) are key components of cell cycle machinery in mammalian cells. These proteins are believed to drive cell cycle progression by associating with their kinase partners, cyclin-dependent kinases, and by directing phosphorylation of critical cellular substrates. In addition, D-cyclins play a kinase-independent role by sequestering cell cycle inhibitors p27(Kip1) and p21(Cip1). In the past, we and others generated cyclin D1-deficient mice and have shown that these mice display developmental abnormalities, hypoplastic retinas, and pregnancy-insensitive mammary glands. To test the significance of cyclin D1-p27(Kip1) interaction within a living mouse, we crossed cyclin D1-deficient mice with mice lacking p27(Kip1), and we generated double-mutant cyclin D1(-/-)p27(-/-) animals. Here we report that ablation of p27(Kip1) restores essentially normal development in cyclin D1-deficient mice. Our results provide genetic evidence that p27(Kip1) functions downstream of cyclin D1.

Trigonella foenum graecum (fenugreek) seed extract as an antineoplastic agent

The antineoplastic effect of Trigonella foenum graecum seed extract has been evaluated in the Ehrlich ascites carcinoma (EAC) model in Balb-C mice. Intra-peritoneal administration of the alcohol extract of the seed both before and after inoculation of EAC cell in mice produced more than 70% inhibition of tumour cell growth with respect to the control. Treatment with the extract was found to enhance both the peritoneal exudate cell and macrophage cell counts. The extract also produced a significant antiinflammatory effect. We report here the antiinflammatory and antineoplastic effects, of Trigonella foenum graecum seed extract.

First aid and basic life support skills training early in the medical curriculum: curriculum issues, outcomes, and confidence of students

BACKGROUND

The importance of training physicians and other health care professionals in first aid and basic life support (BLS) is now widely recognized. The Faculty of Medicine and Health Sciences of the United Arab Emirates University have been offering formal training in these skills to 1st-year medical students since 1989. The aim of this study was to determine the efficacy of the program and the extent to which it provides students with confidence to perform skills on their own after training.

DESCRIPTION

165 of 180 male and female students comprising 3 cohorts (91.7% response rate) completed a self-administered anonymous questionnaire. The questionnaire contained open- ended and Likert-type questions regarding course organization, content, strengths and weaknesses, teaching--learning approaches, and skills development and confidence. The authors analyzed assessment outcomes and associations between self-perceived levels of confidence and ability to practice.

EVALUATION

Students were uniformly enthusiastic and highly motivated by the program. Self-assessed confidence in ability to perform skills on their own after completing the program was moderately correlated with perceived frequency of opportunity to practice many skills. There was nevertheless a consistent desire for more practice time.

CONCLUSIONS

The results suggest that the program provides students with sound basic knowledge and adequate practical skills in first aid and BLS and that adequacy of time and physical and human resources are important prerequisites to facilitate practice and engender confidence in skills.

Low-frequency heart rate variability: reproducibility in cardiac transplant recipients and normal subjects

Heart rate variability is a measure of autonomic nervous influence on the heart. It has been suggested that it could be used to detect autonomic reinnervation to the transplanted heart, but the reproducibility of the measurement is unknown. In the present study, 21 cardiac transplant recipients and 21 normal subjects were recruited. Three measurements of heart rate variability were performed during the day: in the morning, in the early afternoon and in the late afternoon. These tests were then repeated 1 week later and then again 1 week after that, making nine tests in all. The within-subject S.D. was 0.49 log units in normal subjects and 0.79 log units in transplant recipients. In both cases, this is about 15% of the population range. There was significant variation in heart rate variability between different times of day in both groups, and from day to day in transplant recipients. It was concluded that the reproducibility of measurements of heart rate variability is low, and that differences between measurements performed at different times of day should be interpreted with caution.

A set of canine interrepeat sequence PCR markers for high-throughput genotyping

One hundred and sixteen interspersed repetitive DNA sequence (IRS)-PCR markers have been developed and characterized from Canis familiaris for high-throughput filter-based genotyping. We present a detailed analysis of markers produced by amplification using primers directed to the conserved regions of the C. familiaris short interspersed nuclear element (Can-SINE). The majority of IRS-PCR markers developed were moderately to highly polymorphic with mean heterozygosity (HET) and polymorphism information content (PIC) values of approximately 0.6. The HET value for 22.3% of the markers exceeded 0.7. We also demonstrate that sequence variation of Can-SINEs between breeds is significant and also represents a rich source of polymorphisms. Mapping of 73 of the markers to the existing integrated linkage-radiation hybrid map enriches the map as well as establishes the utility of the markers. The significance and utility of this new class of IRS-PCR Can-SINE-based markers for high-throughput genotyping is discussed. This method can also be extended to other species that are currently map-poor but have a sufficiently high density of SINEs to allow IRS-PCR.

How high can the temperature of a liquid be raised without boiling?

How high the temperature of a liquid can be raised beyond its boiling point without vaporizing (known as the limit of superheat) is an interesting subject of investigation. A different method of finding the limit of superheat of liquids is presented here. The superheated liquids are taken in the form of drops suspended in a dust free gel. The temperature of the superheated liquid is increased very slowly from room temperature to the temperature at which the liquid nucleates to boiling. The nucleation is detected acoustically by a sensitive piezoelectric transducer, coupled to a multichannel scaler, and the nucleation rate is observed as a function of time. The limit of superheat measured by the present method supersedes other measurements and theoretical predictions in reaching the temperature closest to the critical temperature of the liquids.

A sensitive neutron dosimeter using superheated liquid

The present work relates to a sensitive neutron dosimeter, a device for monitoring neutron dose in some accelerator and reactor sites. This device is capable of measuring a neutron dose as small as 0.1 microSv using superheated liquid as a sensitive liquid. The nucleation was measured by the volumetric method developed in our laboratory. The dose response of superheated drops of four liquids having boiling points of 8.92, -29.79, -40.75 and -45.6 degrees C, irradiated by a 3 Ci Am-Be neutron source has also been presented in this article.

A sleep inducing factor from common Indian toad (Bufo melanostictus, Schneider) skin extract

Bufo melanostictus (common Indian toad) acquire different bioactive substances in their skin during their life-time in wide ecological habitat. Earlier investigation from this laboratory revealed that toad (B. melanostictus) skin extract (TSE) posses different bioactive compounds of different diversity (Das, M., Auddy, B. and Gomes, A., 1996. Pharmacological study of the toad skin extract on experimental animals. Indian J. Pharmacol. 28, 72-76). Among these sleep induction and sleep potentiation indicated the possibility of sleep inducing factor(s) in TSE. One such sleep inducing factor (SIF) was isolated and purified by neutral alumina column chromatography followed by HPLC. Spectroscopy (UV, IR, FAB-MASS) study indicated that the sleep inducing factor was a 880 Dalton conjugated aromatic compound with a hydroxyl and carbonyl functional group. Biological study showed that SIF produced no lethality in male albino mice upto the dose of 8 mg/kg, i.v. Cyproheptadine antagonised SIF induced contraction of isolated smooth muscle indicating histamine/serotonin receptor mediated action of SIF. EEG studies showed that SIF increased sleep and decreased awakening condition of freely moving rats. Biochemical studies showed that SIF produced significant alteration of brain biogenic amine levels, monoamine oxidase (MAO) and tryptophan hydroxylase (TH) activity. This may be the reason of SIF induced sleep, although the SIF induced sleep mechanism needs further detail investigation.

Evaluation of dermal irritancy potential of benzanthrone-derived dye analogs: structure activity relationship

The twelve structural analogs of benzanthrone-derived dyes of commercial use were screened for their dermal irritation potential response using the Draize occlusive patch test. The test dyes, dissolved in DMSO as vehicle, were topically applied on the skin of the male Druckery rats (160 +/- 10 g) according to the OECD protocol. The potential dermal hazard was assessed in terms of the primary cutaneous irritation (PCI) index and irritancy. Irritancy was evaluated according to the AFNOR scale. In terms of irritancy, the twelve benzanthrone dyes qualified as moderately irritant (3.0-5.0) according to the above scale. In decreasing order, PCI index of the various dyes was: Navy Blue R (4.5); Jade Green XBN (4.25); 16, 17-dihydroxydibenzanthrone (3.84); Black NB (3.75), Jade Green 2G (3. 75); 3-bromobenzanthrone (3.58); Brilliant Purple 4R (3.58); Olive D (3.50); Dark Blue 2R (3.41); Olive Green B (3.33); isodibenzanthrone (3.33), and benzanthrone (3.16). These results indicate that benzanthrone-derived dyes/dye intermediates caused dermal toxicity which appears to be influenced by the number of carbonyl and amino-anthraquinone groups as well as by the presence of functional groups like halogen, nitro, hydroxy and methoxy in the parent molecule, benzanthrone.

Alternative medicine and the medical profession: view of medical students and general practitioners

A survey was undertaken to explore the attitudes and practices of general practitioners and medical students in the United Arab Emirates with regards to forms of therapy not generally accepted by conventional medicine, including herbal medicine, acupuncture, homeopathy, spiritual therapy and osteopathy/chiropractic. The study found that alternative medicine is in common use to complement conventional medicine by a section of educated people within the health care system. Our observations lead us to appreciate its role in community health care and indicate a need to design culturally appropriate medical curricula which incorporate information about alternative medicine

Bidder's organ extract induced anaphylaxis in experimental animals

Bidder's organ (BO, a vestigeal organ), present in toad Bufo melanostictus (Schenider), is a characteristic feature of all male bufo. Its possible anaphylactic properties are investigated on experimental animals. BO extract produced both in vivo and in vitro anaphylactic reaction in guineapig. Dyspnoea and bronchoconstriction was a major cause of anaphylactic death. Blood histamine level was significantly increased in the anaphylactic animals. BO extract significantly released histamine from chopped lung preparation, an action antagonised by disodium chromoglycate. BO extract degranulated peritoneal mast cell in vitro. Passive cutaneous anaphylactic reactions were enhanced by BO extract and were significantly inhibited by disodium chromoglycate. Anaphylotoxin (identity not known) present in bidder's organ is probably involved in toad defence.

Hypoxia induces cell-specific changes in gene expression in vascular wall cells: implications for pulmonary hypertension

Mammals respond to reduced oxygen concentrations (hypoxia) in many different ways at the systemic, local, cellular and molecular levels. Within the pulmonary circulation, exposure to chronic hypoxia has been demonstrated to illicit increases in pulmonary artery pressure as well as dramatic structural changes in both large and small vessels. It has become increasingly clear that the response to hypoxia in vivo is differentially regulated at the level of specific cell types within the vessel wall. For instance, in large pulmonary blood vessels there is now convincing evidence to suggest that the medial layer is made up of many different subpopulations of smooth muscle cells. In response to hypoxia there are remarkable differences in the proliferative and matrix producing responses of these cells to the hypoxic environment. Some cell populations proliferate and increase matrix protein synthesis, while in other cell populations no apparent change in the proliferative or differentiation state of the cell takes place. In more peripheral vessels, the predominant proliferative changes in response to hypoxia in the pulmonary circulation occur in the adventitial layer rather than in the medial layer. Here again, specific increases in proliferation and matrix protein synthesis take place. Accumulating evidence suggests that the unique responses exhibited by specific cell types of hypoxia in vivo can be modeled in vitro. We have isolated, in culture, specific medial cell populations which demonstrate significant increases in proliferation in response to hypoxia, and others which exhibit no change or, in fact, a decrease in proliferation under hypoxic conditions. We have also isolated and cloned several unique populations of adventitial fibroblasts. There is good evidence that only certain fibroblast populations are capable of responding to hypoxia with an increase in proliferation. We have begun to elucidate the signaling pathways which are activated in those cell populations that exhibit proliferative responses to hypoxia. We show that hypoxia, in the absence of serum or mitogens, specifically activates select members of the protein kinase C isozyme family, as well as members of the mitogen-activated protein kinase (MAPK) family of proteins. This selective activation appears to take place in response to hypoxia only in those cells exhibiting a proliferative response, and antagonists of this pathway inhibit the response. Thus, there appear to be cells within each organ that demonstrate unique responses to hypoxia. A better understanding of why these cells exist and how they specifically transduce hypoxia-mediated signals will lead to a better understanding of how the changes in the pulmonary circulation take place under conditions of chronic hypoxia.

Chronic hypoxia induces exaggerated growth responses in pulmonary artery adventitial fibroblasts: potential contribution of specific protein kinase c isozymes

Enhanced proliferation of adventitial fibroblasts is a major contributor to the structural remodeling of the pulmonary artery (PA) that occurs during hypoxia-induced pulmonary hypertension. The mechanisms responsible for the exuberant growth of fibroblasts are unknown; however, protein kinase C (PKC) isozymes have previously been shown to be important in the enhanced growth properties of immature PA fibroblasts. We tested the hypotheses that PA adventitial fibroblasts from neonatal calves exposed chronically to hypoxia after birth would express augmented growth responses compared with fibroblasts from the control adventitia and that these properties would be associated with selective changes in expression of PKC isozymes. We studied the effects of serum, purified mitogens, and hypoxia on the growth of aggregate populations of fibroblasts isolated from the PA of neonatal control calves (Neo-C) and calves chronically exposed to hypoxia for 2 wk beginning on Day 1 of life (Neo-Hyp). Neo-Hyp fibroblasts demonstrated higher proliferative capabilities than did Neo-C cells in response to all the stimuli tested. Importantly, hypoxia was found to act synergistically with peptide mitogens (platelet-derived growth factor, basic fibroblast growth factor, insulin-like growth factor-I) to stimulate growth in Neo-Hyp but not in Neo-C cells. Using PKC-isozyme nonselective and selective inhibitors and immunoblot analysis, we found differences in utilization of PKC isozymes in Neo-Hyp and Neo-C fibroblasts and have identified PKC-betaI and -zeta as key contributors to the augmented growth of Neo-Hyp fibroblasts. Although the activity of PKC-betaI and -zeta isozymes was increased by hypoxia in serum-deprived Neo-C and Neo-Hyp fibroblasts, under normoxia, quiescent Neo-Hyp fibroblasts had higher PKC-zeta-specific activity than did Neo-C cells. These results suggest that neonatal PA adventitial fibroblasts acquire new growth properties in the setting of hypoxia- induced pulmonary hypertension and that the augmented proliferative characteristics of the Neo-Hyp fibroblasts might be associated with changes in specifc PKC isozyme expression and activation patterns.

Alternative medicine and the medical profession: views of medical students and general practitioners

A survey was undertaken to explore the attitudes and practices of general practitioners and medical students in the United Arab Emirates with regards to forms of therapy not generally accepted by conventional medicine, including herbal medicine, acupuncture, homeopathy, spiritual therapy and osteopathy/chiropractic. The study found that alternative medicine is in common use to complement conventional medicine by a section of educated people within the health care system. Our observations lead us to appreciate its role in community health care and indicate a need to design culturally appropriate medical curricula which incorporate information about alternative medicine.

Toxicological impact of benzenehexachloride on the behaviour and neuropathology of Heteropneustes fossilis

Toxicological Impact of Benzenehexachloride on the behaviour and Neuropathology of Heteropneustes fossilis. Organochlorine pesticides are widely used in the vast agricultural fields of Assam, India. Run-offs from treated fields contaminates nearby bodies of water with organochlorine compounds, which are neurotoxic to the ichthyofouna. The present work was designed to study the effect of bezenehexachloride on the behaviour and histopathology of Heteropneustes fossilis, as an experimental model. The experimental fish were exposed to different concentrations of the pesticide for 72 hours. After exposure, the fish exhibited various behavioural changes. Histopathological examination of brain tissue revealed cytopathic and gross histopathological alterations, including necrosis and infractional changes. These results are consistent with the finding that organochlorides cause neurotoxic effects.

Negligible male gene flow across ethnic boundaries in India, revealed by analysis of Y-chromosomal DNA polymorphisms

From the historically prevalent social structure of Indian populations it may be predicted that there has been very little male gene flow across ethnic boundaries. To test this finding, we have analyzed DNA samples of individuals belonging to 10 ethnic groups, speaking Indo-European or Austroasiatic languages and inhabiting the eastern and northern regions of India. Eight Y-chromosomal markers, two biallelic and six microsatellite, were studied. All populations were monomorphic for the deletion allele at the YAP (DYS287) locus and for the 119-bp allele at the DYS288 locus. Y-chromosomal haplotypes were constructed on the basis of one RFLP locus and five microsatellite loci. The haplotype distribution among the groups showed that different ethnic groups harbor nearly disjoint sets of haplotypes. This indicates that there has been virtually no male gene flow among ethnic groups. Analysis of molecular variance revealed that there was significant haplotypic variation between castes and tribes, but nonsignificant variation among ranked caste clusters. Haplotypic variation attributable to differences in geographical regions of habitat was also nonsignificant.

Proconvulsive effect of tea (Camellia sinensis) in mice

Investigations were carried out to evaluate the effect of acute and chronic administration of both black and green tea on three models of experimentally induced convulsions in mice. Tea extract (both black and green) significantly accelerated the onset of convulsion, increased the duration of convulsion and mortality in mice. Since both the extracts failed to alter the GABA level in brain, based on the earlier report that both black and green tea might act on Ca(2+) channels, it can be suggested that the observed proconvulsive effect of tea is not mediated through GABA but through Ca(2+) channels.

Mutagenic and genotoxic effects of theophylline and theobromine in Salmonella assay and in vivo sister chromatid exchanges in bone marrow cells of mice

The mutagenic and genotoxic effects of two methylxanthines, theophylline (TH) and theobromine (TB), were assessed in the Ames mutagenicity assay (in strains TA97a, TA100, TA102 and TA104) and in vivo sister chromatid exchanges (SCEs) in bone marrow cells of mice. These are the two most commonly used nervous system stimulators throughout the world. TH is used in the long-term treatment of asthma. Bacterial mutagenicity assay showed very weak mutagenic effects of both drugs in Salmonella strains TA102 and TA104 only in certain concentrations when S9 was added to it. No mutagenic effects were observed in any other strains used in this assay either with or without metabolic activation. But results of in vivo SCE assay indicate that these two drugs can induce significant SCE in bone marrow cells of mice.

The neural mechanism of rectal motility response induced by the epicardial application of lactic acid

The epicardial application of lactic acid induced a biphasic rectal motility response in lightly anaesthetised, open-chested and artificially ventilated cats. This rectal biphasic response is reflexogenic in nature as epicardial lignocaine abolished such response. This rectal biphasic response is abolished by cardiac sympathectomy and reprecipitated by left inferior cardiac afferent nerve stimulation. Such response is also abolished by sacral ventral rhizotomy and reproduced by stimulation of the peripheral cut end of split sacral ventral roots. This indicates that the afferent and efferent pathways for such reflex are lying in the cardiac sympathetic and sacral pelvic nerves, respectively. The higher centers involved for such reflex are lying above the mid-collicular level of the brain as decerebration at the mid-collicular level completely abolished such type of rectal response. Furthermore, the relaxation phase and contraction phase of such rectal response are mediated through nitric oxide release and cholinergic neurones, respectively, as NG-nitro-L-arginine and atropine abolished relaxation and contraction phase of the rectal response, respectively.

Efficacy of minimal dose aprotinin in open heart procedures

In a randomized double blind study, 30 patients posted for CABG surgery were assigned to 3 groups of 10 each. Group A received 140 mg (1,000,000 KIU) of aprotinin after induction of anaesthesia but before sternotomy, an equal amount in the pump prime and a maintenance dose of 70 mg/hr throughout cardiopulmonary bypass (standard dose). Group B received placebo after induction of anaesthesia, 70 mg (500,000 KIU) aprotinin in the pump prime with a placebo as a maintenance dose (minimal dose). Group C received a placebo after induction of anaesthesia, in the prime and as a maintenance dose (control group). The mean chest closure times were insignificantly lower in the aprotinin groups; 35.83 +/- 13.93 mins in group A and 37.5 +/- 10 mins in group B as against 57.25 +/- 26.54 mins in group C. Post-operative haemoglobin loss was significantly lower (P<0.01) in aprotinin groups, 5.42 +/- 1.6 gm in group A and 6.28 +/- 2.49 gms in group B, as against 39.77 +/- 27.51 gm in group C. Whole blood transfusion requirement was also significantly reduced from 4.12 +/- 1.79 units in the control group to 2.5 +/- 0.75 units in group A (p < 0.05) and 2 +/- 1.3 units (p<0.01) in group B. We conclude that a minimal dose of aprotinin 70 mg (500,000 KIU) is effective in reducing postoperative blood loss, blood transfusion requirement and is economical.

Respiratory symptoms and lung function in garage workers and taxi drivers

The aim of this study was to determine the prevalence of some respiratory symptoms and possible diseases among occupationally-exposed garage workers and taxi drivers. This study involved 158 garage workers and 165 taxi drivers, matched for age, sex, nationality and duration of employment. The mean age of 158 Indian subcontinent garage workers was 34.4 +/- 10.4 years; their mean height and weight were 167.7 +/- 6.6 cm and 72.0 +/- 12.3 kg respectively, and the mean duration of employment garage workers was 8.8 +/- 7.6 years. The mean age of 165 Indian subcontinent male taxi drivers was 34.5 +/- 7.7 years; their mean height and weight were 168.7 +/- 6.1 cm and 71.3 +/- 12.6 kg respectively; and the mean duration of employment was 7.5 +/- 5.4 years. The data on chronic respiratory symptoms showed that garage workers had higher prevalence of symptoms than taxi drivers being significantly greater for chronic phlegm, (p < 0.007); dyspneoa (p < 0.001); and sinusitis (p < 0.03). A higher prevalence of all acute symptoms was recorded in garage workers than in taxi drivers, although the differences were significant only for throat (p < 0.02), hearing problems (p < 0.002); nose (dryness, bleeding and secretion) (p < 0.008); and low back pain (p < 0.05). Almost all forced spirometric tests in the exposed garage workers were lower than in taxi drivers. The results of stepwise multiple regression analysis showed that only phlegm, sinusitis, hearing problems, nasal catarrh, throat, low back pain, smoking and FEF25-75, variables were statistically significant predictors as risk factors. In conclusion, the present study suggests that a high prevalence of respiratory symptoms is associated with exposure to motor vehicle exhaust emission in garage working places. Long-term working as garage workers in the United Arab Emirates (UAE), may be associated with the development of chronic respiratory symptoms and have effects on their daily life and health.

Antisera to selected outer membrane proteins of Vibrio cholerae protect against challenge with homologous and heterologous strains of V. cholerae

Each year cholera epidemics occur in various places around the world. Though there is no effective vaccine against cholera, people who recover from an infection usually have prolonged immunity to the disease. Sera from convalescent patients contain antibodies to a number of outer membrane proteins (OMPs) of V. cholerae. We isolated several OMPs (43, 42, 30, and 22 kDa) from V. cholerae V86 E1 Tor Inaba, sequenced their amino-termini, and generated hyperimmune sera against them in rabbits. Antisera to the 43-, 42-, and 22-kDa OMPs, but not the preimmune sera, significantly reduced V. cholerae-induced fluid secretion seen in rabbit intestinal loops challenged with the homologous strain. In addition, a combination of antisera to the different OMPs reduced the fluid secretion induced by challenge with heterologous V. cholerae Ogawa and O139 strains. These results have significance in the development of vaccines to V. cholerae, as the hyperexpression of these OMP encoding genes in vaccine strains may improve the efficacy of cholera vaccines.