RESUMO
The advancement of crystalline growth and characterization tools allows us to investigate novel nonlinear optical substances suitable for photonic applications. Bis-(4-aminopyridine)-zinc(II) acetate (B4AZA), a metal-organic crystal was produced in this study using the slow evaporation procedure at room temperature. Analytical studies such as X-ray crystallography, Fourier transform infrared (FT-IR), UV-visible (UV-Vis), fluorescence, second harmonic generation (SHG), and dielectric tests were used to characterize the as-grown B4AZA crystals. According to the solubility data, the sample has a positive temperature coefficient of solubility. The crystallographic findings show that the B4AZA crystallized in a monoclinic structure with the P21/n space group. Molecular vibrations and functional groups in the substance were determined using the FT-IR technique. The UV-Vis absorbance and transmittance spectra have shown the wide transparency and minimum absorbance of the B4AZA in the near UV and entire visible regions of the electromagnetic spectrum. The bandgap of the B4AZA has been calculated using the Tauc relation and found to be 4.32 eV. The fluorescence spectra have shown a prominent emission peak at 584 nm with an excitation wavelength of 280 nm. The larger Stokes shift found in the fluorescence spectra is advantageous for practical applications. The SHG study revealed that the powdered B4AZA samples generated a second harmonic output. The dielectric test revealed frequency-dependent changes in the dielectric constant and loss factor. Both the dielectric constant and the loss factor decrease exponentially as frequency increases, reaching low values at higher frequencies. The experimental results illustrate the suitability of the B4AZA crystals for photonic applications.
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Anopheles subpictus s.l. Grassi (Diptera: Culicidae) is a malaria vector in South Asia, where insecticides are the mainstay for vector control interventions. Information on any variation in metabolic enzyme levels in mosquitoes is helpful with respect to adapting alternative strategies for vector control. The scarce data on the biochemical basis of insecticide resistance in malaria vectors of Pakistan limit the available information for vector control interventions within the country. The insecticide susceptibility status and its biochemical basis against dichlorodiphenyltrichloroethane (DDT) (4%), deltamethrin (0.05%) and permethrin (0.75%) in An. subpictus s.l. collected from all Tehsils of district Kasur were evaluated. For this purpose, a World Health Organization susceptibility bioassay was performed followed by the detection of altered metabolic enzyme activity using biochemical assays. Similarly, a significant difference in knock-down effect was observed among field collected and susceptible strain against all insecticides 24 h post exposure. The overall mean mortality rates of DDT, deltamethrin and permethrin were 27.86% [95% confidence interval (CI) = 29.65-26.06], 44.89% (95% CI = 46.23-43.54) and 78.82% (95% CI = 80.16-77.47), respectively. The biochemical assays revealed an elevated level of metabolic enzymes in the field population. The results provide evidence of resistance against organochlorine and pyrethroid groups in a field population of An. subpictus s.l. from district Kasur mediated by multiple metabolic mechanisms, including acetylcholinesterases, esterases, cytochrome P450 and glutathione S-transferases.
Assuntos
Anopheles/efeitos dos fármacos , DDT/farmacologia , Resistência a Inseticidas , Inseticidas/farmacologia , Mosquitos Vetores/efeitos dos fármacos , Piretrinas/farmacologia , Animais , Anopheles/metabolismo , Feminino , Inativação Metabólica , Malária/transmissão , Mosquitos Vetores/metabolismo , Paquistão , Plasmodium/fisiologiaRESUMO
Transmission of Hepatitis B Virus (HBV) usually occurs due to the transfusion of blood or blood products from chronic HBV (CHB) or occult HBV-infected (OBI) patients. Besides serological tests, e.g. HBsAg and anti- HBc (total), detection of HBVDNA is necessary for the diagnosis of OBI patients. Different nucleic acid tests (NATs) including real- time-Polymerase Chain Reaction (qPCR) are used to detect HBV- DNA. The NATs are expensive and require technical expertise which are barriers to introduce them in resource-limited settings. This study was undertaken to evaluate the use of Loop-Mediated Isothermal Amplification (LAMP) assay as an alternative to qPCR for the detection of HBV-DNA in CHB and potential OBI patients in resource-limited settings. Following the published protocols with some modifications, a LAMP assay was developed for detection of HBV-DNA by either using a heat block followed by detection in an agarose gel or using a qPCR thermocycler. The LAMP assay was applied to supernatant prepared from heat-treated serum collected from CHB and potential OBI patients. HBV viral load in serum was measured by qPCR using a single-step HBV-DNA quantification kit. Among 200 samples tested, qPCR was capable to detect HBV-DNA in 25.5% of cases, whereas LAMP assay detected HBV-DNA in 43.5% cases. The qPCR was able to detect 11 (9.16%) potential OBI cases, whereas LAMP assay identified HBV-DNA in 43 (35.83%) cases. In addition to tests for HBsAg and/or anti-HBc (total), detection of HBV-DNA by LAMP assay may aid in preventing post-transfusion HBV infection in resource-limited settings.
Assuntos
DNA Viral/sangue , Vírus da Hepatite B/isolamento & purificação , Hepatite B/diagnóstico , Técnicas de Amplificação de Ácido Nucleico , Carga Viral/métodos , Adolescente , Adulto , Idoso , DNA Viral/genética , Testes Diagnósticos de Rotina , Feminino , Hepatite B/sangue , Anticorpos Anti-Hepatite B/sangue , Antígenos de Superfície da Hepatite B/sangue , Vírus da Hepatite B/genética , Vírus da Hepatite B/imunologia , Hepatite B Crônica/sangue , Hepatite B Crônica/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Técnicas de Amplificação de Ácido Nucleico/normas , Reação em Cadeia da Polimerase em Tempo Real/normas , Adulto JovemRESUMO
Smad ubiquitin regulatory factors (SMURFS) belong to the HECT- family of E3 ubiquitin ligases. This family has two members, SMURF1 and SMURF2. SMURFs have emerged as well studied negative regulators of TGF induced intracellular signaling. However, increasingly it is being realized that SMURFs tactfully modulate an array of proteins in different cancers. This review sets spotlight on how SMURF1 and SMURF2 communicate with effectors of different signaling pathways during the multistep progression to cancer. We also summarize how microRNAs (miRNAs) effectively control SMURFs in different cancers. Role of SMURFs is context dependent in different cancers and better concepts related to miRNA regulation of SMURFs in different stages and steps of cancer will be helpful in efficient translation of laboratory findings to clinic.
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Proteínas de Transporte/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Humanos , Modelos Biológicos , Oncogenes , Ligação Proteica , Transdução de SinaisRESUMO
The vibrational dynamics of a newly synthesized tetrastannoxane was characterized with a combination of experimental (Raman, IR and tin-based nuclear resonance vibrational spectroscopy) and computational (DFT/B3LYP) methods, with an emphasis on the vibrations of the tin sites. The cytotoxic activity revealed a significant regression selectively against the human pancreatic cell lines.
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Benzaldeídos/química , Compostos Organometálicos/química , Neoplasias Pancreáticas/química , Neoplasias Pancreáticas/metabolismo , Estanho/química , Linhagem Celular Tumoral , Humanos , Conformação Molecular , Teoria Quântica , Espectrofotometria Infravermelho , VibraçãoRESUMO
Recurrent headache is common in children. Among them migraine is the most common disabling cause of primary headache. It causes serious disability in child's life and family. It causes negative impact on their quality of life. Clinical characteristic of migraine in children differ from adult. It may be shorter in duration and bifrontal or bitemporal in location in contrast to adult which is longer in duration and usually unilateral. It is less common before 3 years of age. Males are more affected before puberty. But after puberty females are predominantly affected. Intensity of pain is moderate to severe. There are some triggering factors. Positive family history usually present. Disability can be assessed by PedMIDAS scale in children and adolescents which is modified version of MIDAS scale for adult. Diagnosis of migraine usually clinical but evaluation should be done to exclude severe underlying secondary cause. Management consists of pharmacological and non pharmacological approach. Parental education, life style modification is the mainstay of management. Acute treatment consists of Acetaminophen, NSAIDs and Triptans. Among Triptans, Sumatriptan nasal spray is only found effective for children. Preventive therapy aims to decrease frequency and severity of headache. Flunarizine, Propranolol, Amitryptylline, Levetiracetam, Valproate, Topiramate are found effective in pediatric age group. Pediatrician should evaluate the child to exclude secondary cause of headache when indicated. They should have also proper knowledge and skills to manage a child having migraine to improve their quality of life and academic achievement.
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Cefaleia , Transtornos de Enxaqueca , Adolescente , Adulto , Anti-Inflamatórios não Esteroides/uso terapêutico , Criança , Pré-Escolar , Feminino , Cefaleia/complicações , Cefaleia/diagnóstico , Cefaleia/tratamento farmacológico , Humanos , Masculino , Transtornos de Enxaqueca/complicações , Transtornos de Enxaqueca/diagnóstico , Transtornos de Enxaqueca/tratamento farmacológico , Qualidade de Vida , Topiramato/uso terapêuticoRESUMO
Cancer is a multifaceted and genomically complex disease. Research over the years has gradually provided a near complete resolution of cancer landscape and it is now known that genetic/epigenetic mutations, inactivation of tumor suppressors, Overexpression of oncogenes, spatio-temporally dysregulated intracellular signaling cascades, epithelial to mesenchymal transition (EMT), metastasis and loss of apoptosis are some of the most extensively studied biological mechanisms that underpin cancer development and progression. Increasingly it is being realized that current therapeutic interventions are becoming ineffective because of tumor heterogeneity and rapidly developing resistance against drugs. Considerable biological activities exerted by bioactive ingredients isolated from natural sources have revolutionized the field of natural product chemistry and rapid developments in preclinical studies are encouraging. Viscum album has emerged as a deeply studied natural source with substantial and multifaceted biological activities. In this review we have attempted to provide recent breakthroughs in existing scientific literature with emphasis on targeting of protein network in cancer cells. We partition this review into different sections, highlighting latest information from cell culture studies, preclinical and clinically oriented studies. We summarized how bioactive ingredients of Viscum album modulated extrinsic and intrinsic pathways in cancer cells. However, surprisingly, none of the study reported stimulatory effects on TRAIL receptors. The review provided in-depth analysis of how Viscum album modulated Endoplasmic Reticulum Stress in cancer cells and how bioactive chemicals tactfully targeted cytoskeletal machinery in cancer cells as evidenced by cell culture studies. It is noteworthy that Viscum album has entered into various phases of clinical trials, however, there are still knowledge gaps in our understanding regarding how various bioactive constituents of Viscum album modulate intracellular signaling cascades in cancer. Better and deeper comprehension oncogenic signaling cascades will prove to be helful in getting a step closer to individualized medicine.
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Neoplasias/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Viscum album/química , Animais , Resistencia a Medicamentos Antineoplásicos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Humanos , Neoplasias/genética , Neoplasias/patologia , Extratos Vegetais/química , Viscum album/fisiologiaRESUMO
Human leukocyte antigen B27 (HLA-B27), a class I molecules of the major histocompatibility complex has a strong disease association with different types of spondarthropathies (SpA). The strength of this disease association varies markedly among racial and ethnic populations. The present study aimed to identify the HLA-B27 antigen frequencies among suspected SpA patients as well as healthy Bangladeshi individuals. The frequency of HLA-B27 was determined in 1500 patients and 1000 healthy subjects attending the Bangabandhu Sheikh Mujib Medical University (BSMMU). HLA-B 27 typing was done by microlymphocytotoxicity test using commercial kit. A total of 738 (49.2%) suspected SpA patients and 107 (10.7%) healthy subjects tested positive for HLA-B27 antigen with higher frequency among younger age groups (54.9%, 52.4% and 56.2% in 0-14 years, 15-24 years and 25-34 years of age respectively). The male female positivity was almost same (11.4% and 9.6%) among control group, but in patient group it was 53.0% and 41.2% respectively. The findings of this hospital based study showed a high frequency of HLA-B27 among suspected SpA patients with male preponderance which is comparable with neighboring countries.
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Antígeno HLA-B27/sangue , Espondiloartropatias/sangue , Centros de Atenção Terciária , Adolescente , Adulto , Bangladesh , Criança , Pré-Escolar , Feminino , Humanos , Testes Imunológicos , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Espondiloartropatias/fisiopatologia , Adulto JovemRESUMO
Gamma interferon (IFN-γ) plays an important role in the immune response to live measles virus vaccination. To study the immune response to measles vaccination, IFN-γ level was estimated in 30 children. Of these, 24 children vaccinated with a single dose of measles vaccine at nine months of age and 06 children vaccinated with a second dose during the Measles Catch-up Immunization campaign. Measles vaccine strain was cultured in Vero cell line and the Tissue Culture Infective Dose (TCID)50 was used as standard live virus. Peripheral blood Mononuclear cells (PBMCs) was separated by Ficoll-Hypaque density gradient centrifugation and stimulated with measles virus antigens and mitogens (lectin), cultured in CO2 and iFN-γ level was measured from culture supernatant by ELISA. On stimulation with measles antigen and lectin respectively, IFN-γ level was highest (105 pg/ml and 226.54 pg/ml) in the 109-120 months age group while it was lowest (12.97 ± 8.16 pg/ml and 13.16 ± 8.0 pg/ml) in the 61-72 months age group. No significant difference was observed in IFN-γ level after stimulation with either measles antigen or lectin among well-nourished (p < 0.8) and mal-nourished (p < 0.7) children suggesting that nutritional status did not have any effect on IFN-γ level. However, IFN-γ level was higher in children who received two dose of measles vaccine than those who received a single dose (p < 0.001).
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Interferon gama/sangue , Vacina contra Sarampo/imunologia , Bangladesh , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Humanos , Imunização Secundária , Lactente , Vacina contra Sarampo/administração & dosagem , Vírus do Sarampo/imunologiaRESUMO
Various abnormalities of coagulation such as primary hemostasis, secondary hemostasis and fibrinolysis have been reported in patients with subclinical and overt hypothyroidism. Platelets are major elements of primary hemostasis and endothelial repair. Platelet size, shape and number are the determinant of platelet function. The objective of this study was to assess primary hemostasis by PFA-100 (Platelet Function Analyzer-100) and its relation with TSH and FT4 levels in newly diagnosed overt and subclinical hypothyroid patients. This cross-sectional study was conducted in the Department of Physiology, Dhaka Medical College, Bangladesh from January 2016 to December 2016. Twenty overt and 20 subclinical hypothyroid patients with age ranging from 18 to 55 years were selected as study group and twenty age and sex matched healthy subjects were considered as control group. Patients were selected from Outpatients Department of Endocrinology and Nuclear Medicine & Allied Sciences of Dhaka Medical College Hospital, Dhaka on the basis of exclusion and inclusion criteria. For assessment of primary hemostasis, PFA-100 was analyzed by SIEMENS-INNOVANCE-PFA-200. For statistical analysis Unpaired Student's 't' test, Chi square test and Pearson's correlation co-efficient (r) test were performed. PFA-100 was significantly higher (p<0.001) in overt and subclinical hypothyroid patients as compared to healthy adult subjects. In overt and subclinical hypothyroidism using PFA-100, we found that the existence of a hypocoagulable state is due to a defect in primary hemostasis. Moreover, PFA-100 may replace the in-vivo bleeding time as a screening test for primary hemostasis in routine clinical practice.
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Hipotireoidismo , Adulto , Humanos , Adolescente , Adulto Jovem , Pessoa de Meia-Idade , Estudos Transversais , Bangladesh , Hipotireoidismo/diagnóstico , Hipotireoidismo/complicações , Hemostasia , TireotropinaRESUMO
Dengue fever (DF) and dengue haemorrhagic fever (DHF) are now endemic in Bangladesh with outbreaks being reported quite frequently. This cross sectional study was done clinically suspected dengue patients were selected from different hospitals of Dhaka city, Bangladesh, from January 2008 to December 2008. The clinical features, risk factors and laboratory findings associated with dengue infection were investigated among 201 clinically suspected patients. Antibodies were detected in 137(68.2%) cases. Of these, 80(58.4%) were primary and 57(41.6%) as secondary dengue cases according to presence of dengue-specific IgM and/or IgG antibodies. Among primary cases, 70(87.5%) were DF and 10(12.5%) were DHF cases, in contrast to secondary cases, where 10(18.1%) were DF and 47(81.9%) were DHF cases. Majority (57.9%) of patients presented with Grade I and 42.1% had Grade II disease. Patients between 16-30 years were the most vulnerable age group (81.3% DF and 71.9% DHF patients). Males out-numbered females with 72.5% male vs. 27.5% female patients having DF and 68.4% male vs. 31.6% female patients having DHF. The monsoon period was the peak season for dengue infection. Headache and arthralgia were the most frequent symptoms in both DF and DHF, but vomiting was more common in DHF. The Tourniquet test was significantly positive among DHF than DF cases (p = 0.001). Platelet count was the only laboratory parameter that showed significantly higher values among DHF than DF cases (p = 0.001).
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Dengue/epidemiologia , Adolescente , Adulto , Idoso , Anticorpos Antivirais/sangue , Bangladesh/epidemiologia , Estudos Transversais , Dengue/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contagem de PlaquetasRESUMO
The chick embryo is a versatile host system in diagnostic virology, especially for isolation of herpes simplex viruses. In this study, samples obtained from 57 clinically diagnosed patients with active herpetic lesions (35 genital & 22 non-genital) were cultured by chick embryo method for isolation of herpes simplex virus. After inoculation onto the chorioallantoic membrane (CAM) of 10-11 days old chick embryo, typical CAM reactions (pocks) appeared in 23(40.3%) samples after 3 days. CAM reactions were identified and typed by direct fluorescence antibody test and 22(95.6%) of 23 isolates gave positive results. Of this, 9(40.9%) were HSV-1 & 13(59.1%) were HSV-2. HSV-1 was isolated from 8(36.4%) of non-genital samples and from 1(7.1%) genital sample. HSV-2 was isolated from 13(92.8%) of genital samples, but none were isolated from non-genital samples. High isolation rate was obtained from vesicular stage of both non-genital (71.5%) and genital (57.1%) samples and from early lesions (sampled within 72 hours) of non-genital (50%) and genital (52.9%) specimen. The chorioallantoic membrane of chick embryo it is a simple, cheap and efficient method of cultivation of some viruses, including HSV. Thus, in settings where cell culture facilities are not available, it can be used for the isolation of herpes simplex viruses from clinical samples.
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Simplexvirus/isolamento & purificação , Animais , Embrião de Galinha , Herpesvirus Humano 1/isolamento & purificação , Herpesvirus Humano 2/isolamento & purificação , HumanosRESUMO
Hepatitis B virus (HBV) infection is of global public health concern. Among various serological tests used for the diagnosis and screening of HBV infection, the enzyme-linked immunosorbent assay (ELISA) to detect hepatitis B surface antigen (HbsAg) is most widely used. The present study was designed to develop and standardize a cost effective in-house ELISA for the detection of HbsAg and compare its performance with two established commercial kits. The concentrations of coating antibody, conjugates and sera were fixed by checkerboard titration. Using known HBsAg positive and negative sera, four different concentrations (1, 0.5, 0.25 and 0.125 microg/well) of coating anti-HBs were applied. Similarly, serial dilutions of patients' sera (1 in 2, 1 in 3, 1 in 5 and 1 in 9) and conjugates (1 in 2, 1 in 3, 1 in 5, 1 in 9 and 1 in 17) were evaluated by checkerboard titration. The optimal concentration of coating antibody was determined at 0.25 microg/well and 1 in 9 dilution for both conjugates and sera. The performance comparison of our in-house ELISA showed excellent correlation with two commercial kits (Pearson 0.957, P = 0.001 for monoclonal antibody coated kit and Pearson 0.929, P = 0.000 for polyclonal antibody coated kit) when OD values were compared. All commercial kit proven positive samples was positive while all negative samples were negative with the in-house ELISA resulting in 100% sensitivity and specificity. The results of our study demonstrated that our in-house ELISA for detection of HBsAg was equally as sensitive and specific as two well-known commercial kits. Thus, this system may be a useful tool for diagnostic and screening purposes, as well as outbreak investigations.
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Ensaio de Imunoadsorção Enzimática/normas , Recursos em Saúde/provisão & distribuição , Antígenos de Superfície da Hepatite B/sangue , Vírus da Hepatite B/isolamento & purificação , Bangladesh , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Kit de Reagentes para Diagnóstico/normas , Sensibilidade e EspecificidadeRESUMO
Human papillomavirus (HPV) high risk genotype infection and HPV viral load influences the development of invasive cervical cancer and cervical intra-epithelial neoplasia (CIN). HPV DNA testing for screening of cervical cancers may play a potential role in its early detection and management. The present study detected HPV DNA and estimated HPV viral load in different types of cervical lesions among Bangladeshi women. Using the Hybrid Capture 2 (HC2) assay, HPV DNA was tested among 68 women between 25-70 years of age. A total of 13 (19.1%) cases were positive for HPV DNA. The highest viral load (501 x 10(3) copies/ml) was detected in a patient with invasive carcinoma, while the lowest viral load (105 x 10(3) copies/ml) was detected from a case of chronic cervicitis. The mean viral load in CIN I was 119.25 x 10(3) +/- 12.5 x 10(3) copies/ml (range: 110 x 10(3) - 137 x 10(3) ) and 208.50 x 10(3) +/- 0.59 x 10(3) copies/ml (range: 139 x 10(3) - 305 x 10(3)) in CIN II/III. Interestingly, HPV DNA was detected from a patient with normal cytological findings. Our study observed a moderate presence of high-risk HPV genotypes among women with cervical lesions. The HPV viral load varied with the age of the patients and stage of cervical lesions. The HC2 assay is a promising tool for diagnosing high-risk HPV infection especially before cytology tests show any abnormality.
Assuntos
DNA Viral/isolamento & purificação , Testes de DNA para Papilomavírus Humano/métodos , Papillomaviridae/genética , Papillomaviridae/isolamento & purificação , Neoplasias do Colo do Útero/virologia , Carga Viral , Adulto , Idoso , Bangladesh , Feminino , Humanos , Pessoa de Meia-Idade , Infecções por Papillomavirus/virologiaRESUMO
BACKGROUND: Germline alterations of the CDH1 (E-cadherin) tumor suppressor gene have been reported in several epithelial malignancies like hereditary diffuse gastric cancer and lobular breast cancer. E-cadherin plays a central role in proliferation, maintenance of cell-to-cell adhesion, polarity, and epithelial-mesenchymal transition of tissue cells. It is necessary to analyze the impact of the CDH1 germline sequence variants on protein and predict its clinical significance in breast cancer (BC) progression. The aim of the current study was to evaluate the impact and association of CDH1 gene potentially pathogenic variants/likely pathogenic variants (PVs/LPVs) with the initiation and progression of BC. MATERIALS AND METHODS: In this study, the clinical data of 200 BC patients have been analyzed based on the type of BC, age, grade, stage, hormonal status, and risk factors. Blood samples from 50 healthy donors were used as a control. Furthermore, CDH1 gene molecular analysis, along with in silico analysis, was provided to assess the invasiveness and progression of BC caused by the E-cadherin protein. RESULTS: Four variants were identified by genetic screening within the CDH1 gene that included variations in exons 7, 8, 10, 11, and 13. Exon 10 had splice site mutation at position c.1337C>A, affecting the protein structure. In exon 11, there was an insertion of T base at position 1669, resulting in truncated protein compared to a normal one that can lead to the disease-causing non- sense-mediated decay and exon 13 variant c.2076T>C has already known polymorphism. In silico analysis of CDH1 showed the presence of the different variants that indicated the overall disruption of protein structure and function. CONCLUSIONS: The further functional analysis of these variants and their association with BC can be ensured by increasing the sample size and in vivo studies using mouse models.
Assuntos
Neoplasias da Mama , Neoplasias Gástricas , Animais , Camundongos , Humanos , Feminino , Neoplasias da Mama/genética , Predisposição Genética para Doença , Caderinas/genética , Adesão Celular , Neoplasias Gástricas/metabolismo , Células Germinativas/metabolismo , Células Germinativas/patologia , Linhagem , Antígenos CD/genéticaRESUMO
Reliable neutron star mass measurements are key to determining the equation of state of cold nuclear matter, but such measurements are rare. Black widows and redbacks are compact binaries consisting of millisecond pulsars and semi-degenerate companion stars. Spectroscopy of the optically bright companions can determine their radial velocities, providing inclination-dependent pulsar mass estimates. Although inclinations can be inferred from subtle features in optical light curves, such estimates may be systematically biased due to incomplete heating models and poorly understood variability. Using data from the Fermi Large Area Telescope, we have searched for gamma-ray eclipses from 49 spider systems, discovering significant eclipses in 7 systems, including the prototypical black widow PSR B1957+20. Gamma-ray eclipses require direct occultation of the pulsar by the companion, and so the detection, or significant exclusion, of a gamma-ray eclipse strictly limits the binary inclination angle, providing new robust, model-independent pulsar mass constraints. For PSR B1957+20, the eclipse implies a much lighter pulsar (1.81 ± 0.07 solar masses) than inferred from optical light curve modelling.
RESUMO
Herpes simplex viruses (HSV) multiply readily on the chorioallantoic membrane (CAM) of embryonated hen's egg and produce easily visible foci or pocks on this membrane. In the present study, pocks produced by the two antigenic types of HSV (1 & 2) were compared to evaluate the effectiveness of typing HSV isolates by pock size on CAMs. A total of 57 HSV isolates from both non-genital and genital samples were typed by the pock size produced on the CAMs of fertile hen's eggs. Twenty two HSV isolates yielded visible pocks on CAM, of which 9 (40.9%) produced small pocks, while 13 (59.1%) produced large pocks. All pocks produced on CAM were confirmed by antigenic typing by the Direct Fluorescent Antibody (DFA) method. HSV isolates which produced small pocks were in complete (100%) concordance with HSV type-1, while those producing larger pocks were in full (100%) concordance with HSV type-2. Thus, the pock size on CAM of embryonated fertile hen's egg may be used as a simple and relatively inexpensive biological marker for the differentiation of HSV types 1 & 2.
Assuntos
Herpes Simples/virologia , Herpesvirus Humano 1/isolamento & purificação , Herpesvirus Humano 2/isolamento & purificação , Virologia/métodos , Animais , Bangladesh , Biomarcadores , Galinhas , Membrana Corioalantoide , HumanosRESUMO
We use a series of magnetohydrodynamic simulations including both radiative and protostellar outflow feedback to study environmental variation of the initial mass function (IMF). The simulations represent a carefully-controlled experiment whereby we keep all dimensionless parameters of the flow constant except for those related to feedback. We show that radiation feedback suppresses the formation of lower mass objects more effectively as the surface density increases, but this only partially compensates for the decreasing Jeans mass in denser environments. Similarly, we find that protostellar outflows are more effective at suppressing the formation of massive stars in higher surface density environments. The combined effect of these two trends is towards an IMF with a lower characteristic mass and a narrower overall mass range in high surface density environments. We discuss the implications for these findings for the interpretation of observational evidence of IMF variation in early type galaxies.
RESUMO
A total of 280 fecal specimens from patients with acute gastroenteritis attending one rural hospital (Dharmapasha health complex, Sunamgonj) in Bangladesh from August 2004 to May 2006 were tested for rotavirus by Polyacrylamide Gel Electrophoresis (PAGE). The diversity of rotavirus was investigated using electropherotyping and reverse transcription-PCR amplification of the VP7 and VP4 genes. The electrophoretic patterns of dsRNA of rotavirus showed 9 different migrations (6 long and 3 short) by PAGE. In the year 2004-2006, group A rotavirus was detected in 112 out of 280(40.0%) specimens. G and P genotyping was performed among the 46 representative positive specimens, 20(43.5%) were emerging strain G9P[8], which were associated with VP6 genotype II (subgroup II), and NSP4 genotype B, followed by 16(34.8%) G2P[4], 8(17.4%) G1P[8] and 2(4.4%) G4P[8] strains. G9P[8] was found to be the most predominant strain in 2004, but the prevalence rate abruptly decreased during the period 2005-2006. In addition G2P[4] was the most prevalent strain in 2005 and 2006. G1P[8] was less prevalent in the study period then the previous years. Nucleotide Sequence identity of VP7 gene of G9 rotaviruses were higher than 99.4% with each other and all the G9 rotavirus strains in this study clustered in a single branch of the phylogenetic tree. Nucleotide sequence identity of complete VP4 gene of P[8] rotaviruses were more than 99.7% with each other and all the P[8] rotavirus strains in this study grouped in a single cluster suggesting recent emergence from a common ancestor. An important finding of this study is that the genetic profile of rotavirus is changing within very short period in Bangladesh and continued surveillance of the circulating strains is necessary to detect new strains or new variants which can escape immune protection induced by available vaccines.
Assuntos
Rotavirus/classificação , Rotavirus/genética , Adolescente , Adulto , Idoso , Antígenos Virais/genética , Bangladesh , Proteínas do Capsídeo/genética , Criança , Pré-Escolar , Diarreia/virologia , Eletroforese em Gel de Poliacrilamida , Gastroenterite/virologia , Genótipo , Glicoproteínas/genética , Humanos , Lactente , Pessoa de Meia-Idade , Filogenia , Toxinas Biológicas/genética , Proteínas não Estruturais Virais/genéticaRESUMO
In haemodialysis patients, hepatitis B virus infection has higher mortality and is more likely to result in the carrier state. Although Hepatitis B vaccine is effective in producing protection against HBV infection, the antibody response may be variable. In this study, seroprotection rate of hepatitis B vaccine in maintenance haemodialysis patients was studied after primary vaccination and after completion of the full vaccine regime. 50 unvaccinated patients on maintenance haemodialysis were included in this study. Patients negative for HBsAg, Anti-HBc (total) and Anti-HCV were vaccinated with 40 microg of Engerix B following a schedule of 0, 1, and 2 months. The antibody titer was tested at 3rd month and if the titer was < 10 or between 10-100 mIU/ml, they were given another 4th dose of vaccine at 6th month, and their antibody titer was tested again at 7th month. In maintenance haemodialysis patients, the response rate to HBV vaccine was 44% after the primary vaccination and 80% after completion of the full vaccine regime.