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1.
Plant Cell Rep ; 34(10): 1735-45, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26063614

RESUMO

KEY MESSAGE: The present work demonstrates that induction of defense-related genes in tomato by neem extract was mediated by protein-protein and DNA-protein interactions. The induction of elicitor-mediated defense responses in plants is known, but the molecular mechanisms underlying its induction are not well studied. In the present study, third node leaf from the base of aseptically raised tomato plants was treated with aqueous fruit extracts of Azadirachta indica A. Juss. (neem). Samples were collected from the treated node at 24-h intervals for up to 96 h and analyzed for the gene expression of phenylalanine ammonia lyase (PAL), Peroxidase (POX) and Polyphenol Oxidase (PPO), ß-actin (standard). Samples were collected from elicitor-induced node at 5-min interval up to 70 min for analysis of protein-protein and DNA-protein interactions. The results demonstrated the induction of expression of PAL, POX and PPO due to the treatment whereas no change was observed in the expression of ß-actin. There was disappearance of lower molecular weight proteins which cross-linked with other proteins to form complexes. MALDI-TOF MS analysis revealed the interaction of mitogen-activated protein kinases (MAPK). The analysis of proteins interacted with DNA after induction by neem extract indicated the involvement of WRKY transcriptional factors. Neem-elicited defense responses could possibly due to interaction of proteins with other proteins and transcription factors with DNA which might be crucial in enhancing the expression of defense-related genes (PAL, POX and PPO).


Assuntos
Azadirachta/química , Frutas/química , Extratos Vegetais/farmacologia , Proteínas de Plantas/metabolismo , Solanum lycopersicum/metabolismo , DNA de Plantas/metabolismo , Solanum lycopersicum/efeitos dos fármacos
2.
Tissue Antigens ; 82(2): 125-30, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23772862

RESUMO

In this study we have evaluated an alternative 96-well format flow cytometry based (FCtox) method which enable simultaneous detection of cytotoxicity and human leukocyte antigen (HLA) antibody binding. Comparable results were obtained in side-by-side comparisons with conventional complement-dependent cytotoxicity (CDC) and flow cytometric crossmatch (FCXM) in terms of sensitivity and specificity. There was 91 and 93% agreement between results obtained by FCtox and CDC for T and B cells, respectively. In addition, comparable results were obtained with FCtox IgG and FCXM IgG for both T and B cells. Furthermore, compared with a recently developed and highly sensitive Luminex based C1q assay we obtained close to 90% method agreement with the FCtox assay. Our alternative cytotoxicity and IgG binding assay which exhibit low intra-and inter-assay variation will improve the workflow and speed up the pre-transplant testing and also allow continuous monitoring of assay performance and proper quality assurance.


Assuntos
Testes Imunológicos de Citotoxicidade/métodos , Citotoxicidade Imunológica , Citometria de Fluxo/métodos , Linfócitos B/citologia , Linfócitos B/imunologia , Testes Imunológicos de Citotoxicidade/normas , Citometria de Fluxo/normas , Humanos , Imunoglobulina G/metabolismo , Masculino , Variações Dependentes do Observador , Ligação Proteica , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Linfócitos T/citologia , Linfócitos T/imunologia
3.
Mymensingh Med J ; 30(4): 1154-1162, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34605490

RESUMO

Determinants of pre-hospital delay after myocardial infarction, strictly among South-Asian rural community, till now is largely unknown. And Bangladesh is not an exception. It is a fact that though around two third of its population still live in villages, we do not know what factors are having influence on such delay. To find out these primers of time consumption before seeking medical help, this is a picture of a medical college hospital situated in a rural precinct. This cross-sectional analytical study was conducted among 98 patients came with Myocardial Infarction (MI) who had met inclusion and exclusion criteria from July 2019 and December 2019. Both STEMI & NSTEMI patients were selected as they have similar attributes. Data was collected in the coronary care unit using a preformed questionnaire. Among 98 MI patients, where 16 female and 82 male patients had average age 53±12 years. Average income rural community was around 100 USD. Almost 50% of sample were illiterate or below 5th grade. On average 6.6 hours (95% CI: 3.5-12.3) were required to reach CCU after symptom onset, whereas distance to first medical contact (FMC) was about 10.2 Km (95% CI: 6.4-16.2). Median distance to nearest PCI-capable hospital was 140 Km (IQR- 20 Km). Only 28% of patients could reach hospital within 2 hours, where 85% had onset of symptom while they were at home. Tertiary level medical college (74.5%) followed by Upazilla (Sub-urban) government health complex (22.4%) were frequent site of FMC. Principle mode of transport to hospital was CNG-three-wheeler (75% of cases). Logistic regression analysis showed only low literacy was as significant predictor about more than 2 hours pre-hospital delay (OR=2.58; p=0.043). Other factors such as low income (OR=2.51; p=0.126), diabetes mellitus (OR=2.99; p=0.059), female sex (OR=1.56; p=0.753), house wife (OR=1.88; p=0.547), previous MI (OR=1.52; p=1.000), symptom ignorance (OR=2.14; p=0.455) increases pre-hospital delay and distance to FMC <10 Km (OR=0.44; p=0.079) no significant prediction of pre-hospital delay after myocardial infarction. As rural community has less access to education low literacy has a significant impact on pre-hospital delay after myocardial infarction. So measures should be taken in rural areas through patient education and social awareness program regarding MI symptom and danger of delayed medical attention.


Assuntos
Infarto do Miocárdio , Intervenção Coronária Percutânea , Adulto , Idoso , Bangladesh/epidemiologia , Estudos Transversais , Feminino , Hospitais , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/terapia , População Rural , Fatores de Tempo
4.
Mymensingh Med J ; 29(1): 66-72, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31915338

RESUMO

Various forms of sexual dysfunction occur in men with diabetes mellitus (DM) including disorders of libido, ejaculatory problems, and erectile dysfunction (ED). This cross sectional study was conducted in a tertiary hospital of Bangladesh from December 2017 to May 2018 to find out the frequency and risk factors of ED in subjects with type 2 DM (T2DM). One hundred fifty (150) consecutive male patients with T2DM attending the Endocrinology outpatient department (OPD) of the hospital during the study period were evaluated for the presence of ED by using the International Index of Erectile Function-5 (IIEF-5) questionnaire; their socio-demographic, anthropometric, and clinical data were also recorded. Glycemic status was assessed by measurement of fasting plasma glucose (FPG) and HbA1c. Morning serum testosterone was measured in all. Among 150 subjects 68(45.3%) had ED; ED was mild in 14.7%, mild to moderate in 18.0%, moderate in 6.0% whereas severe ED was present in 6.7% of the subjects. The subjects with ED had higher mean age, longer duration of DM, higher body mass index (BMI), higher HbA1c, higher FPG, higher serum creatinine, and lower serum testosterone level than those without ED. Study subjects in the higher age group and higher duration of DM had higher frequencies of ED. IIEF-5 score showed significant negative correlation with age, duration of DM, HbA1c, fasting plasma glucose, serum creatinine and significant positive correlation with serum testosterone. In logistic regression analysis, duration of DM and serum testosterone were found be independent predictors of ED. Frequency of ED among Bangladeshi type 2 diabetic males is high; duration of DM and serum testosterone are independent predictors of ED in them.


Assuntos
Diabetes Mellitus Tipo 2/complicações , Disfunção Erétil/epidemiologia , Adulto , Distribuição por Idade , Bangladesh/epidemiologia , Glicemia/análise , Índice de Massa Corporal , Estudos Transversais , Diabetes Mellitus Tipo 2/epidemiologia , Disfunção Erétil/etiologia , Hemoglobinas Glicadas/análise , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Prevalência , Fatores de Risco , Testosterona/sangue
5.
Mymensingh Med J ; 28(4): 862-865, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31599252

RESUMO

Although esthetic factors might limit by the presentation of materials used, all-metal complete cast crown should always be offered to patients requiring restoration of endodontically treated posterior tooth. The complete cast crown has the highest longevity of all fixed restorations. It could be used to rebuild a single tooth or a retainer for a fixed prosthesis. It involves all the axial walls as well as the occlusal surface of the tooth to be restored. All restorations are placed in the oral environment in contact with the gingival tissue. Thus clinicians must choose nontoxic or least toxic metal alloys, since any release of elements that might cause reactions. This study was designed to observe clinical responses of nickel chromium alloy and gold alloy cast crown and provide guidance to ascertain the best alloy for cast metal crown, which serves better functional restoration.


Assuntos
Ligas de Ouro , Níquel , Coroa do Dente , Cromo , Ligas de Cromo , Corrosão , Ouro , Humanos
6.
Mymensingh Med J ; 28(4): 744-751, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31599236

RESUMO

Acute myocardial infarction (AMI) patients constitute a large proportion of admissions in coronary care unit and their management and risk stratification is of immense importance. A decrease in serum albumin concentration might be associated with an increased risk in the incident of both cardiovascular diseases and worse hospital outcome. We assessed whether serum albumin levels at admission was associated with in-hospital adverse outcome in patients with first attack of acute myocardial infarction (AMI). The aim of the study was to evaluate association of serum albumin level with in-hospital outcome in patients with first attack of acute myocardial infarction. This cross-sectional analytical study was conducted in the department of cardiology in Mymensingh Medical College Hospital, Mymensingh, Bangladesh from March 2017 to February 2018. Total 374 patients of first attack of acute myocardial infarction included considering inclusion and exclusion criteria. The sample population was divided into two groups: Group I (Patients with acute myocardial infarction with serum albumin <3.5gm/dl) and. Group II (Patients with acute myocardial infarction with serum albumin ≥3.5gm/dl). Serum albumin level was measured within 24 hours of admission and the incidence of in-hospital major cardiac outcomes was observed. In this study mean±SD serum albumin level of Group I, Group II were 3.02±0.12gm/dl, 4.48±0.50gm/dl respectively. In Group I patient, 52(59.80%), 7(8.00%), 10(11.50%), developed heart failure, cardiogenic shock, arrhythmias respectively and 8(9.20%) died and in Group II patient 20(7.90%), 7(2.80%), 8(3.20%) developed heart failure, cardiogenic shock, arrhythmias respectively and 4(1.60%) died out of them and all of these outcome were statistically significant. Mean±SD duration of hospital stay of the study population according serum albumin level, in Group I, 5.76±1.83 days, in Group II, 4.40±1.22 days which was statistically significant (p<0.05). In conclusion, patient with first attack of acute myocardial infarction serum albumin level below 3.50gm/dl increased the risk of worse in-hospital outcome.


Assuntos
Infarto do Miocárdio/metabolismo , Albumina Sérica/metabolismo , Bangladesh , Estudos Transversais , Humanos , Choque Cardiogênico
7.
Mymensingh Med J ; 27(3): 508-512, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30141439

RESUMO

Incidence of coronary artery disease (CAD) is increasing in developing countries in Bangladesh with improvement of socioeconomic status, urbanization, changes of dietary habits and lifestyle. Dyslipidaemia is one of the major contributors increase CAD risk. This study was aimed to find out the association of low level HDL-C with acute coronary syndrome. This cross sectional study was conducted in the department of cardiology, Mymensingh Medical College Hospital, Mymensingh, Bangladesh from August 2009 to May 2010. Sociodemographic characteristics, smoking, hypertension, FBS, serum total cholesterol level, HDL-C, LDL-C, Triglyceride level were important variable considered. A total number of 100 respondents consisted of 50 cases (patient) Group I and 50 healthy people (control) Group II. Investigations included ECG, Troponin-I, FBS and Fasting Lipid Profile. The data was analyzed by computer with the help of SPSS. Chi-square test, T-test, ANOVA test used as test of significance. The mean level in cases of HDL-C 39.3±5.1 and in control level HDL-C 34.2±3.4 statistically significant (p<0.0001). In both group low concentration HDL-C (<40mg/dl) risk for CAD. Un-adjusted odds ratio 95% CI determinants of ACS, HDL-C of OR was 0.2. So, HDL-C is not protective factor. In multivariate logistic regression analysis that adjusted for confounders of HDL-C level (age, sex, smoking, hypertension, TC, LDL-C, TG) associated with ACS. HDL-C was strong predictor of ACS (RR in the highest) compared with lowest quarantile = 0.02; (95% CI=0.003-0.173; P for trend <0.0001). The study reflected that low HDL-C level associated with ACS. Categorization of patients with ACS on the basis HDL-C level may be helpful for risk stratification and management.


Assuntos
Síndrome Coronariana Aguda , HDL-Colesterol , Síndrome Coronariana Aguda/sangue , Bangladesh , Colesterol/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Estudos Transversais , Humanos , Fatores de Risco , Triglicerídeos/sangue
8.
Mymensingh Med J ; 27(2): 289-293, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29769492

RESUMO

Cardiovascular diseases (CVD) is the leading cause of death worldwide, responsible for one third of death, coronary artery disease (CAD) is the most common cause. Dyslipidaemiais one of the major contributors increased of CAD risk. This study was aimed to find out the relationship between triglyceride and HDL cholesterol ratio with acute coronary syndrome. This cross sectional study was conducted in the department of Cardiology, Mymensingh Medical College Hospital from August 2009 to May 2010. Smoking, hypertension, serum total cholesterol level, serum HDL-C, LDL-C, triglyceride (TG) level were important variable considered. A total number of 100 respondents consisted of 50 cases (patient) and 50 healthy persons (control). Investigations included ECG, Troponin-I, FBS and lipid profile. The data was analyzed by computer with the help of SPSS; Chi-square test, 't' test, ANOVA test used as test of significance. The mean level in cases of TG 168.2±88.0 vs. HDL 41.3±5.1 in control level TG 141.2±45.3 and HDL 34.2±3.4. TG/HDL ratio cases 4.2±1.7 and control 4.1±1.3. This ratio >4 is atherogenic for CAD. Unadjusted odds ratio TG/HDL ratio level high (>1). In multivariable regression analysis, TG/HDL ratio was strong relation with ACS. The study reflected that high TG/HDL ratio is associated with ACS. Categorization of patient with ACS on the basis of high TG/HDL ratio will be helpful for risk stratification and management.


Assuntos
Síndrome Coronariana Aguda , HDL-Colesterol , LDL-Colesterol , Triglicerídeos , Síndrome Coronariana Aguda/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Doença da Artéria Coronariana , Estudos Transversais , Humanos , Fatores de Risco , Triglicerídeos/sangue
9.
Mymensingh Med J ; 27(1): 68-73, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29459594

RESUMO

The objective of this prospective experimental clinical trial was to evaluate intraoral burning sensation in response to heat-cured and self-cured acrylic resin denture base material and carried out in the department of Prosthodontics of Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh from February 2014 to September 2015. Forty eight patients were evaluated in this study; of them 35(72.92%) patients were male and 13(27.08%) patients were female with age range from 24 to 70 years. In this study 48 patients were evaluated in term of burning sensation, of them 24 patients were provided with heat-cured acrylic resin denture and were considered as Group A and 24 patients were provided with self-cured acrylic resin denture and were considered as Group B. In Group A 14(58.4%) at 1st week, 2(8.4%) at 1st month, 10(41.8%) at 3rd month and 5(21.0%) at 6th month developed burning sensation. On the other hand the values were 18(75.0%), 22(91.6%), 14(58.2%) and 2(8.4%) at 1stweek, 1st month, 3rd month, and 6th month respectively. Chi-square test was done for statistical analysis and p value was <0.05. So, results were statistically significant.


Assuntos
Bases de Dentadura , Temperatura Alta , Dor , Sensação , Resinas Acrílicas , Adulto , Idoso , Bangladesh , Bases de Dentadura/efeitos adversos , Humanos , Pessoa de Meia-Idade , Dor/etiologia , Estudos Prospectivos , Adulto Jovem
10.
Mymensingh Med J ; 26(4): 721-731, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29208858

RESUMO

Coronary heart disease (CHD) is the most common cause of heart disease and is the single most important cause of premature death in developed world. Recognizing a patient with ACS is important because the diagnosis triggers both triage and management. cTnI is 100% tissue-specific for the myocardium and it has been shown to be a very sensitive and specific marker for acute myocardial infarction (AMI). Ventricular function is the best predictor of death after an acute coronary syndrome. It serves as a marker of myocardial damage, provides information on systolic function as well as diagnosis and prognosis. The study aimed at investigating the impact of elevated Troponin-I level on LV ejection fraction and in-hospital outcomes in patients with first attack of Non ST-segment Elevation Myocardial Infarction (NSTEMI). This prospective analytical study was conducted in the Department of Cardiology in Mymensingh Medical College Hospital from December 2015 to November 2016. Total 130 first attack of NSTEMI patients were included considering inclusion and exclusion criteria. The sample population was divided into two groups: Group I - Patients with first attack of NSTEMI with good LV function (LVEF: ≥55%). Group II - Patients with first attack of NSTEMI with LV systolic dysfunction (LVEF: <55%). Then Troponin-I and LVEF levels were correlated using Pearson's correlation coefficient test. In this study mean Troponin-I of Group I and Group II were 5.53±7.43 and 16.46±15.79ng/ml respectively. It was statistically significant (p<0.05). Echocardiography showed that patients with high Troponin-I level had low ejection fraction (LVEF) and patients with low Troponin-I level had preserved ejection fraction (LVEF). Analysis showed that patients with severe left ventricular systolic dysfunction (LVEF <35%) had the highest level of Troponin-I with worse in-hospital outcomes and vice versa-the patients with the preserved systolic function (LVEF ≥55%) had the lowest levels of Troponin-I with better in-hospital outcomes. In our study, it also showed that the levels of Troponin-I had negative correlation with LV ejection fraction levels, with medium strength of association (r= -0.5394, p=0.001). The study enabled us to conclude that, the higher was the Troponin-I level, the lower was the LV ejection fraction level and thus worse in-hospital outcomes in first attack of NSTEMI patients.


Assuntos
Infarto do Miocárdio sem Supradesnível do Segmento ST , Troponina I , Disfunção Ventricular Esquerda , Humanos , Infarto do Miocárdio sem Supradesnível do Segmento ST/sangue , Infarto do Miocárdio sem Supradesnível do Segmento ST/complicações , Prognóstico , Estudos Prospectivos , Volume Sistólico , Resultado do Tratamento , Troponina I/sangue , Disfunção Ventricular Esquerda/sangue , Disfunção Ventricular Esquerda/etiologia
11.
J Colloid Interface Sci ; 299(2): 785-90, 2006 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-16580008

RESUMO

This paper reports the pi-A isotherms and spectroscopic characteristics of mixed Langmuir and Langmuir-Blodgett (LB) films of nonamphiphilic carbazole (CA) molecules mixed with polymethyl methacrylate (PMMA) and stearic acid (SA). pi-A isotherm studies of mixed monolayer as well as the remarkable change in collapse pressure of the mixed monolayer isotherms definitely show that CA is incorporated into PMMA and SA matrices. However, CA is stacked in the PMMA/SA chains and forms microcrystalline aggregates, as is evidenced from the scanning electron micrograph picture. The nature of these aggregated species in the mixed LB films has been revealed by UV-vis absorption and fluorescence spectroscopic studies. The presence of two different kinds of band systems in the fluorescence spectra of the mixed LB films have been observed. This may be due to the formation of low-dimensional aggregates in the mixed LB films. Intensity distribution of different band systems is highly sensitive to the microenvironment of two different matrices as well as also on the film thickness.

12.
Interdiscip Sci ; 8(3): 229-40, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26253718

RESUMO

RuBisCO (EC 4.1.1.39), a key enzyme found in stroma of chloroplast, is important for fixing atmospheric CO2 in plants. Alterations in the activity of RuBisCO could influence photosynthetic yield. Therefore, to understand the activity of the protein, knowledge about its structure is pertinent. Though the structure of Nicotiana RuBisCO has been modeled, the structure of tomato RuBisCO is still unknown. RuBisCO extracted from chloroplasts of tomato leaves was subjected to MALDI-TOF-TOF followed by Mascot Search. The protein sequence based on gene identification numbers was subjected to in silico model construction, characterization and docking studies. The primary structure analysis revealed that protein was stable, neutral, hydrophilic and has an acidic pI. The result though indicates a 90 % homology with other members of Solanaceae but differs from the structure of Arabidopsis RuBisCO. Different ligands were docked to assess the activity of RuBisCO against these metabolite components. Out of the number of modulators tested, ergosterol had the maximum affinity (E = -248.08) with RuBisCO. Ergosterol is a major cell wall component of fungi and has not been reported to be naturally found in plants. It is a known immune elicitor in plants. The current study throws light on its role in affecting RuBisCO activity in plants, thereby bringing changes in the photosynthetic rate.


Assuntos
Ergosterol/farmacologia , Fungos/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo , Solanum lycopersicum/enzimologia , Ativação Enzimática/efeitos dos fármacos , Ergosterol/química , Fotossíntese/efeitos dos fármacos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
13.
Artigo em Inglês | MEDLINE | ID: mdl-25956326

RESUMO

Fluorescence Resonance Energy Transfer between two organic dyes Fluorescein and Rhodamine 6G was investigated in aqueous solution in presence and absence of synthetic clay laponite. Spectroscopic studies suggest that both the dyes were present mainly as monomer in solution. Fluorescence Resonance Energy Transfer occurred from Fluorescein to Rhodamine 6G in solutions. Energy transfer efficiency increases in presence of laponite and the maximum efficiency was 72.00% in aqueous laponite dispersion. Energy transfer efficiency was found to be pH sensitive. It has been demonstrated that with proper calibration it is possible to use the present system under investigation to sense pH over a wide range from 1.5 to 8.0.


Assuntos
Fluoresceína/química , Corantes Fluorescentes/química , Rodaminas/química , Transferência Ressonante de Energia de Fluorescência , Silicatos/química , Água/química
14.
Peptides ; 11(6): 1103-8, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2087435

RESUMO

A number of cyclic and linear fragments and analogues of MCH were synthesized and their biological potencies tested using the isolated carp scale melanophore assay. In this system the cyclic portion MCH(5-14) exhibited only 0.1% bioactivity, which was markedly enhanced by the addition of the exocyclic sequences MCH(15-17) and MCH(1-4). The exocyclic sequence itself, MCH(1-4,15-17), had minimal activity, however. Substitution of Tyr11 with phenylalanine reduced the potency of the ring structure MCH(5-14) by about 4-fold. Substitution of Gly8 with D-alanine reduced the potency of MCH(5-14) 16-fold, while both substitutions together caused a still more marked reduction (200-fold) in bioactivity. Linearized fragments of MCH, extending from MCH(15-17) to [Cys(Acm)5,14]MCH(1-17), showed a progressive increase in potency. The linearized forms of MCH, MCH(5-17) and MCH(5-14), were approximately 100-fold or less potent than their cyclic forms. The significant increases in bioactivity produced by the addition of the C- and N-terminal exocyclic sequence even to these linearized forms further emphasizes the importance of these regions for interaction at the receptor site.


Assuntos
Carpas/metabolismo , Hormônios Hipotalâmicos , Melaninas/química , Melanóforos/química , Fragmentos de Peptídeos/química , Hormônios Hipofisários/química , Sequência de Aminoácidos , Animais , Bioensaio , Técnicas In Vitro , Melaninas/síntese química , Melaninas/fisiologia , Melanóforos/fisiologia , Dados de Sequência Molecular , Fragmentos de Peptídeos/síntese química , Fragmentos de Peptídeos/fisiologia , Hormônios Hipofisários/síntese química , Hormônios Hipofisários/fisiologia , Relação Estrutura-Atividade
15.
J Biomol Struct Dyn ; 2(5): 879-98, 1985 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-3916936

RESUMO

An energy term, representing the N-H...O type of hydrogen bond, which is a function of the hydrogen bond length (R) and angle (theta) has been introduced in an energy minimization program, taking into consideration its interpolation with the non-bonded energy for borderline values of R and theta. The details of the mathematical formulation of the derivatives of the hydrogen bond function as applicable to the energy minimization have been given. The minimization technique has been applied to hydrogen bonded two and three linked peptide units (gamma-turns and beta-turns), and having Gly, Ala and Pro side chains. Some of the conformational highlights of the resulting minimum energy conformations are a) the occurrence of the expected 4----1 hydrogen bond in all of the burn-turn tripeptide sequences and b) the presence of an additional 3----1 hydrogen bond in some of the type I and II tripeptides with the hydrogen bonding scheme in such type I beta-turns occurring in a bifurcated form. These and other conformational features have been discussed in the light of experimental evidence and theoretical predictions of other workers.


Assuntos
Físico-Química , Ligação de Hidrogênio , Peptídeos , Fenômenos Químicos , Dipeptídeos , Matemática , Oligopeptídeos , Conformação Proteica , Termodinâmica
16.
Protein Pept Lett ; 10(6): 591-7, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14683511

RESUMO

An analysis of hydrogen bonding patterns of cyclic decapeptide (CDP) beta-sheet structures has resulted in a 'non-intuitive' design of cyclic decapeptides wherein their beta-turns and residue positions can be fixed by choosing 2 of the 10 residues, i.e. positions i and i+4, to be Prolines or N-substituted residues. This sequence relationship between the two Pro or N-substituted residues is shown to uniquely define the conformation of the CDP. Furthermore, this design of the 2 beta-turn, beta-sheet CDP structure is expected to be characterised by residues disposed in an exclusive fashion in which four residues are on one side of the ring, two on the other and the four corner residues in the beta-turn are in the plane of the ring. This opens up the possibility of fine-tuning the four residues facing one way and /or the two residues facing the other way such that a library containing a myriad of chemically diverse systems could be obtained. The design process along with the molecular modelling of specific CDP-s and the building of a CDP library are discussed in detail.


Assuntos
Oligopeptídeos/química , Biblioteca de Peptídeos , Peptídeos Cíclicos/química , Aminoácidos/química , Ligação de Hidrogênio , Modelos Moleculares , Conformação Proteica , Estereoisomerismo
17.
Adv Exp Med Biol ; 242: 35-42, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3245513

RESUMO

Morphological analysis of compartments in terms of volumes and the orientation of the cells and their nuclei within very small mesenteric arteries and arterioles is being carried out. Samples were from simultaneously sham operated and instrumented control and one-clip two kidney Goldblatt sustained (30 days) hypertensive dogs. Collection of specimens was standardized, i.e. sampling location, perfusion fixation, embedding, staining, and sectioning by methods proven to preserve in vivo dimensions. Serial thick cross sections (0.5 mu) were subjected to high voltage electromicrography (1.0 MeV) at 2500x and then linearly enlarged 3x photographically. The glossy micrographs (7500x) were made into montages and the contours of the smooth muscle layer (vascular smooth muscle), the endothelium (E), nuclei (N), and the internal lamina (IL) were digitized on a large GTCO digi-pad with input to a microcomputer (PC-Limited, Turbo) equipped with a 20 MB hard disk and coprocessor. Solid and transparent image reconstructions and computerized dissection of cell compartments were performed. Compartment volumes of vascular smooth muscle, IL, E and N, and individual cell and nuclear volumes, as well as nuclear/cytoplasmic ratios were calculated. Image reconstructions are presented. The emphasis is on methods and these are discussed in terms of useability for determining accurate microvessel morphology in health and disease, with particular emphasis on assessment of hypertrophy and hyperplasia in experimental hypertension, and architectural angiogenesis in general.


Assuntos
Artérias/ultraestrutura , Arteríolas/ultraestrutura , Processamento de Imagem Assistida por Computador/métodos , Mesentério/irrigação sanguínea , Microscopia Eletrônica/métodos , Modelos Anatômicos , Modelos Cardiovasculares , Animais , Núcleo Celular/ultraestrutura , Cães , Microcirculação
18.
J Nutr Sci Vitaminol (Tokyo) ; 22(3): 181-6, 1976.
Artigo em Inglês | MEDLINE | ID: mdl-966075

RESUMO

An acute dose (10 mg/100 g body weight) of biotin at the post-implantation stage (day 14 and 15) inhibited the fetal and placental growth, and in few rats it also caused resorption of fetuses and placentae. The maintenance of pregnancy with normal fetal and placental growth was effected with estrogen therapy, but progesterone failed to correct the biotin-induced effect. The uterine and placental glycogen, RNA and protein levels, as well as, glucose-6-phosphate dehydrogenase activity in the ovary, liver and uterus showed a reduction following biotin treatment. Estrogen therapy under such conditions corrected these adverse effects of biotin overdose, while progesterone had no significant effects. The study suggests that the acute dose of biotin at an advance stage of pregnancy may cause adverse effects on the physiological regulation of gestation, possibly by creating deficiency of estrogen and gestagen. The possible role of estrogen in the fetal and placental growth and regulation of gestagen secretion is discussed.


Assuntos
Biotina/efeitos adversos , Desenvolvimento Embrionário/efeitos dos fármacos , Hormônios Esteroides Gonadais/uso terapêutico , Complicações na Gravidez/induzido quimicamente , Prenhez/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Animais , Estradiol/uso terapêutico , Feminino , Reabsorção do Feto/induzido quimicamente , Glucosefosfato Desidrogenase/metabolismo , Glicogênio/metabolismo , Ácidos Nucleicos/metabolismo , Tamanho do Órgão , Doenças Placentárias/induzido quimicamente , Gravidez , Progesterona/uso terapêutico , Ratos
19.
J Nutr Sci Vitaminol (Tokyo) ; 21(2): 89-101, 1975.
Artigo em Inglês | MEDLINE | ID: mdl-1171166

RESUMO

An acute dose of biotin (10 mg/100 g body weight) in two subcutaneous injections when given to a rat on day 1 and 2 of pregnancy, caused resorption of fetuses and placentae. Pregnancies under such biotin-treated conditions were maintained by continued estrogen or progesterone therapy. Biotin-treated pregnant rats failed to maintain normal levels of uterine weight, glycogen and protein as well as hepatic protein concomitantly with the loss of pregnancy. Estrogen therapy under such conditions improved all the parameters in these organs including the placenta, but progesterone therapy did not. Glucose-6-phosphate dehydrogenase (G-6-PD) activity in ovary, adrenal, liver and uterus was also reduced following biotin-induced loss of pregnancy which had been improved by estrogen or progesterone therapy. Nevertheless, estrogen was superior to progesterone in stimulating the enzyme activity in these organs excepting the adrenal. As far as the tissue response to biotin, estrogen or progesterone in the nonpregnant rat is concerned, biotin and progesterone exerted a suppressing effect on uterine glycogen and protein and also on liver protein, while estrogen stimulated them. Similarly biotin and progesterone adversely affected G-6-PD activity in all the organs studied except the liver and adrenal. Estrogen stimulated the enzyme activity in all these organs but adrenal. The study suggests that the primary reason for an acute dose of biotin-induced loss of pregnancy is blockage of estrogen production, which probably regulates endogenous progesterone secretion. The associated metabolic derangements are probably secondary to estrogen deficiency and are discussed.


Assuntos
Biotina/efeitos adversos , Prenhez/efeitos dos fármacos , Animais , Desenvolvimento Embrionário/efeitos dos fármacos , Estrogênios/fisiologia , Estrogênios/uso terapêutico , Feminino , Morte Fetal/induzido quimicamente , Feto/fisiologia , Fígado/metabolismo , Ovário/metabolismo , Gravidez , Progesterona/fisiologia , Progesterona/uso terapêutico , Ratos , Útero/metabolismo
20.
Indian J Exp Biol ; 29(7): 605-10, 1991 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1839018

RESUMO

Effects of dietary and supplemented dextrose energy on the role of corticosterone (Comp. B) or dehydroepiandrosterone (DHA) in spermatogenic and steroidogenic activity in the bilaterally adrenalectomised prepubertal rat testis were studied. Adrenalectomy reduced the body and testis weight, numbers of the stage VII cell types [spermatogonia A (A), preleptotene (PL) and pachytene (P) spermatocytes and step 7 spermatid (7)], testicular delta 5-3 beta-hydroxysteroid dehydrogenase (delta 5-3 beta-OH-SDH) activity and serum testosterone. Adrenalectomy also caused reduction of energy intake due to loss of appetite which was stimulated by hormone replacement therapy. Treatment of adrenalectomised rats with DNA or corticosterone enhanced the spermatocyte population and the enzyme activity, especially after 30 days of age. Dextrose supplementation with hormone treatment however, did not produce significant additive effect on stage VII cell counts, but delta 5-3 beta-OH-SDH activity showed additive effect in this age group. Results suggest that adrenal steroids regulate testicular steroidogenesis and spermatogenesis during the prepubertal ages by modifying the supply of dietary glucose.


Assuntos
Corticosterona/fisiologia , Desidroepiandrosterona/fisiologia , Carboidratos da Dieta/farmacologia , Glucose/farmacologia , Espermatogênese/efeitos dos fármacos , Testículo/efeitos dos fármacos , Testosterona/biossíntese , Adrenalectomia , Fatores Etários , Animais , Apetite/fisiologia , Corticosterona/farmacologia , Desidroepiandrosterona/farmacologia , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ratos , Maturidade Sexual/efeitos dos fármacos , Testículo/anatomia & histologia , Testículo/fisiologia
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