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1.
Mymensingh Med J ; 31(1): 161-164, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34999697

RESUMO

Helicobacter Pylori (H Pylori) that infects about 90% people of developing countries causes dyspepsia and upper gastrointestinal lesions. The aim of this study was to detect the trend of H Pylori active infection and to investigate the endoscopic findings of H Pylori infected dyspeptic patient of Bangladesh. In this prospective study, 360 dyspeptic patients (Male-251, Female-109) were recruited. Patients having alarm features, history of gastrectomy and malignancy were excluded from this study. Non-invasive fecal antigen test for H Pylori was done of all patients. All selected patients were sent for upper gastrointestinal endoscopy. Helicobacter Pylori fecal antigen was found positive in 134(37.2%) from 360 dyspeptic patients (age 14-80 years). Among 360 patients 303 (80.16%) had macroscopic endoscopic mucosal lesions. H Pylori infected 114 patients had endoscopic mucosal abnormality. H Pylori non-infected 189 patients also had mucosal lesion. Twenty patients (35.08%) had H Pylori infection among the 57 patients having endoscopic normal looking mucosa. This study revealed that active H Pylori infection rate is declining in Bangladesh. Risk of endoscopic mucosal lesion is more expected in H Pylori active infection.


Assuntos
Dispepsia , Infecções por Helicobacter , Helicobacter pylori , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Dispepsia/epidemiologia , Fezes , Feminino , Infecções por Helicobacter/complicações , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
2.
Mymensingh Med J ; 28(2): 405-409, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31086158

RESUMO

Globus sensation is a subjective feeling of a lump or foreign body in the throat without interfering swallowing of food. It is a persistent and distressing sensation in throat. It affects about 6% of population. But cause of globus is still unknown. Exact aetiology of globus is considered to be multifactorial. Some other studies also show association between globus and psychological distress including anxiety and depression. As there is no established pharmacological treatment, adequate investigations with negative result could reassure patients and improve their symptoms. In this prospective study consecutive patients with globus symptoms examined by upper GIT endoscopy with attention to larynx, epiglottis, base of tongue, both pyriform fossa and hypo-pharynx using Olympus forward viewing video Gastroscope (GIF Q-150 & GIF Q-170) to exclude organic lesion and was conducted in the department of Gastroenterology, Bangabandhu Sheikh Mujib Medical University (BSMMU) and North East Medical College, Sylhet from 1st July 2014 to 31 December 2016. Their psychological status and epidemiological information including personal and family history were noted in a pre-designed data sheet. Total 104 patients were examined, among them definite anxiety was found in 36(34.95%) and borderline feature of anxiety was found in 19(18.44%) and 48(46.60%) were free of anxiety. Incidence of anxiety was significantly higher among females and was more prevalent among housewife, married people and people from rural community. In this series, 13(12.5%) patients had definite depression and 29(27.9%) patients had borderline depression, while 61(59.2%) patients had no feature of depression. Incidence of depression was significantly higher among females, housewife and married people. Organic lesion is rare in patients with globus symptoms. Globus sensation is more common among females. Psychological factors like anxiety and depression are frequently associated with globus sensation.


Assuntos
Transtornos da Motilidade Esofágica/diagnóstico , Esofagoscopia , Faringe/inervação , Transtornos das Sensações/etiologia , Sensação/fisiologia , Ansiedade/epidemiologia , Bangladesh/epidemiologia , Endoscopia , Transtornos da Motilidade Esofágica/epidemiologia , Feminino , Humanos , Prevalência , Estudos Prospectivos , Transtornos das Sensações/diagnóstico , Transtornos das Sensações/epidemiologia
3.
Bangladesh Med Res Counc Bull ; 40(3): 89-91, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26402971

RESUMO

This cross sectional study was carried out in the department of gastroenterology, BIRDEM, Dhaka from January 2010 to May 2011 to determine the role of ascitic fluid ADA and serum CA-125 in the diagnosis of clinically suspected tubercular peritonitis. Total 30 patients (age 39.69 ± 21.26, 18M/12F) with clinical suspicion of tuberculosis peritonitis were included in this study after analyzing selection criteria. Laparoscopic peritoneal biopsy with 'histopathological diagnosis' was considered gold standard against which accuracics of two biomarkers (ADA & CA-125) were compared. Cut off value of ADA and CA-125 are 24 u/l, 35 U/ml respectively. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of ADA as a diagnostic modality in tuberculos peritonitis were 87.5%, 83.33%, 95.45%, 62.5% and 86.67% respectively where as CA-125 was found to have 83.33% sensitivity, 50% specificity, 86.9% positive predictive value, 42.85% negative predictive value and 76.6% accuracy. Both biomarkers are simple, non-invasive, rapid and relatively cheap diagnostic test where as laparoscopy is an invasive procedure, costly & requires trained staff and not without risk and also not feasible in all the centre in our country. So ascitic fluid ADA and serum CA-125 are important diagnostic test for peritoneal tuberculosis.


Assuntos
Adenosina Desaminase/análise , Líquido Ascítico/química , Antígeno Ca-125/sangue , Peritonite Tuberculosa/diagnóstico , Adolescente , Adulto , Estudos Transversais , Diagnóstico Diferencial , Humanos , Entrevistas como Assunto , Pessoa de Meia-Idade , Pesquisa Qualitativa , Sensibilidade e Especificidade , Adulto Jovem
4.
Bangladesh Med Res Counc Bull ; 39(3): 116-9, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26118158

RESUMO

Double balloon enteroscopy (DBE) is a newly developed endoscopic modality for diagnosis and treatment of small bowel disorders. The aim of this study was to evaluate the diagnostic and therapeutic impact of DBE in patient with suspected small bowel disease. This was a prospective study. Sixty one double balloon enteroscopy procedures (30 antegrade 31 retrograde) were done in thirty six patients (20M/16F, mean age 40 ± 12.5 range 16-65 years ) at gastroenterology department, Sir Salimullah Medical College, Dhaka between October 2011 and September 2012. Indications for DBE included chronic abdominal pain 14 (38.9%), obscure GI bleeding 11 (30.56%), Small bowel obstruction 05 (13.89%), and chronic diarrhea 06 (16.67%). The morphologic findings were ulcerations 13 (36.11%), growth 03 (8.33%), vascular ectasia 03 (8.33%) and polyp 01 (2.78%). Therapeutic interventions were performed in one patient only. No serious complications were observed. Diagnostic yields in case of chronic abdominal pain, chronic diarrhea, obscure GI bleeding and small bowel obstruction were 50%, 66%, 63% and 40% respectively. The findings were adenocarcinoma 04 (11%), lymphoma 03 (8.4%), tuberculosis 03 (8.4%), non specific findings 05 (13.9%), IPSID 01(2.8%), Crohn's disease 01 (2.8%), vascular ectasia 03 (8.33%) and normal 16 (44.44%). DBE is well tolerated, feasible and useful technique for the diagnosis as well as treatment of small intestinal disorders.


Assuntos
Enteroscopia de Duplo Balão , Enteropatias/diagnóstico , Enteropatias/cirurgia , Intestino Delgado , Adolescente , Adulto , Idoso , Bangladesh , Estudos de Coortes , Feminino , Humanos , Enteropatias/etiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
5.
Am J Physiol Heart Circ Physiol ; 302(10): H2031-42, 2012 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-22427522

RESUMO

To bridge the gap between two-dimensional cell culture and tissue, various three-dimensional (3-D) cell culture approaches have been developed for the investigation of cardiac myocytes (CMs) and cardiac fibroblasts (CFs). However, several limitations still exist. This study was designed to develop a cardiac 3-D culture model with a scaffold-free technology that can easily and inexpensively generate large numbers of microtissues with cellular distribution and functional behavior similar to cardiac tissue. Using micromolded nonadhesive agarose hydrogels containing 822 concave recesses (800 µm deep × 400 µm wide), we demonstrated that neonatal rat ventricular CMs and CFs alone or in combination self-assembled into viable (Live/Dead stain) spherical-shaped microtissues. Importantly, when seeded simultaneously or sequentially, CMs and CFs self-sorted to be interspersed, reminiscent of their myocardial distribution, as shown by cell type-specific CellTracker or antibody labeling. Microelectrode recordings and optical mapping revealed characteristic triangular action potentials (APs) with a resting membrane potential of -66 ± 7 mV (n = 4) in spontaneously contracting CM microtissues. Under pacing, optically mapped AP duration at 90% repolarization and conduction velocity were 100 ± 30 ms and 18.0 ± 1.9 cm/s, respectively (n = 5 each). The presence of CFs led to a twofold AP prolongation in heterogenous microtissues (CM-to-CF ratio of 1:1). Importantly, Ba(2+)-sensitive inward rectifier K(+) currents and Ca(2+)-handling proteins, including sarco(endo)plasmic reticulum Ca(2+)-ATPase 2a, were detected in CM-containing microtissues. Furthermore, cell type-specific adenoviral gene transfer was achieved, with no impact on microtissue formation or cell viability. In conclusion, we developed a novel scaffold-free cardiac 3-D culture model with several advancements for the investigation of CM and CF function and cross-regulation.


Assuntos
Comunicação Celular/fisiologia , Fibroblastos/citologia , Modelos Animais , Miócitos Cardíacos/citologia , Engenharia Tecidual/métodos , Potenciais de Ação/fisiologia , Animais , Células Cultivadas , Estimulação Elétrica , Fibroblastos/fisiologia , Hidrogéis , Potenciais da Membrana/fisiologia , Microeletrodos , Miócitos Cardíacos/fisiologia , Ratos , Ratos Sprague-Dawley
6.
Mymensingh Med J ; 20(4): 614-9, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22081179

RESUMO

Chronic hepatitis B and C virus infection can lead to cirrhosis and hepatocellular carcinoma. Several studies investigated the diagnostic and prognostic value of some biochemical markers to detect the hepatic fibrosis and found a correlation between serum markers and hepatic fibrosis. Among them serum hyaluronic acid (HA) has been identified as a potential marker of fibrosis or cirrhosis in different studies. A prospective study in 60 subjects was conducted to evaluate the association between serum HA and hepatic fibrosis. Thirty consecutive patients with chronic HBV or HCV infection undergoing liver biopsy were studied. Sera were obtained for HA using enzyme linked protein binding assay. Patients with hepatic fibrosis had higher serum HA concentration compared with healthy subjects (236.65 ± 227.07 vs. 23.32 ± 14.22 respectively, p<0.001). Correlation was found between high serum HA concentration and increasing degree of hepatic fibrosis (R-0.322 and p<0.041). This study had shown a good correlation between serum HA and different stages of hepatic fibrosis. So serum HA may be used as a useful marker of hepatic fibrosis.


Assuntos
Hepatite B Crônica/complicações , Hepatite C Crônica/complicações , Ácido Hialurônico/sangue , Cirrose Hepática/diagnóstico , Adulto , Feminino , Hepatite B Crônica/sangue , Hepatite C Crônica/sangue , Humanos , Cirrose Hepática/sangue , Cirrose Hepática/etiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
7.
J Indian Med Assoc ; 109(12): 873-8, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23469566

RESUMO

BRCA1 gene expression in familial breast cancer is mainly focused on mutational analysis. However in sporadic cancers BRCA1 protein expression is the main area of interest because somatic inactivation of one allele of the gene is likely to occur during the oestrogen mediated proliferation at puberty and subsequent tumourigenic events take place in the same cell. Standard immunohistochemical analysis was used to assess BRCA1 and oestrogen/progesterone receptor (ER/PR) status in familial and sporadic breast cancer patients and correlation of BRCA1 protein expression with histopathological features ER/PR status was studied in these tumours. One hundred and seventy-seven sporadic tumours (group A) and 28 familial tumours (patients with history of breast cancer in first or second degree relative ie, group B) were studied. In group A, 61 tumours had absent/reduced BRCA 1 protein expression; 30 (49%) out of these were negative for ER/PR receptors. In group B, 18 patients had absent/reduced BRCA1 protein expression, and 10 (55.6%) out of these, were ER/PR negative. Overall in 2 groups, 82 tumours were of grade 1, 61 tumours of grade 2 and 62 tumours were of grade 3 differentiation. Test of proportion showed that percentage of ER/PR negativity is significantly higher than ER/PR positivity in sporadic as well as in familial tumours with absent/ reduced BRCA 1 protein expression (p < 0.05). Sporadic tumours with deranged BRCA1 protein expression like familial tumours have more unfavourable histopathological characteristics and are likely to be of higher grade and oestrogen receptor negative


Assuntos
Proteína BRCA1/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Carcinoma/metabolismo , Carcinoma/patologia , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo , Adulto , Neoplasias da Mama/genética , Carcinoma/genética , Feminino , Expressão Gênica , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estudos Prospectivos , Adulto Jovem
8.
J Food Sci Technol ; 47(1): 89-93, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23572607

RESUMO

Carabeef samples were sliced, pressed, cured and divided into 6 groups. Starter cultures (Micrococcus varians M483 (MV), Staphylococcus carnosus (SC), Lactobacillus sakei (LS), M. varians M483+ Lb. sakei and Staph. carnosus + Lb. sakei) were inoculated at the dose of 10(6)-0(7)cfu/g and stored at 10 ± 1°C for 7 days. Uninoculated samples were maintained as control. Samples were then divided into 2 treatment groups. Samples of treatment 1 (T1) were smeared with a paste of turmeric followed by application of a thick layer of the paste of garlic, cumin, black pepper and red pepper whereas, samples of treatment 2 (T2) were applied with a thick layer of spices as above without turmeric. With the gradual fall in pH there was a reduction in water-holding capacity (WHC) of samples. The WHC of samples treated with SC+LS of T1 reduced to 6.3 ± 0.03 cm(2) and those inoculated with MV+LS of T2 to 6.2 ± 0.03 cm(2). The extract release volume (ERV) increased in all samples during storage. The least ERV of 11.7 and 11.6 ml were recorded in samples inoculated with MV of T1 and T2, respectively. The tyrosine (TV) and thiobarbituric acid (TBA) number of turmeric treated samples were significantly lower than non turmeric treated samples. The samples inoculated with LS had the least TV of 30.9 mg tyrosine/100 g of meat and TBA number of 0.06 mg manoladehyde/kg of meat. Samples inoculated with MV and LS of both T1 and T2 were better in physico-chemical qualities.

10.
Animal ; 2(6): 879-82, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22443667

RESUMO

The study describes the standardization of a suitable semen cryopreservation protocol for the first time in mithun (Bos frontalis) and birth of the first mithun calf through artificial insemination. The semen samples were collected from adult bulls through the rectal massage method and cryopreserved in liquid nitrogen using tris-egg yolk-glycerol diluent. The diluted semen samples were packaged in 0.50 ml straws and kept at 5°C for 4 h for equilibration. Following the equilibration, the straws were frozen into liquid nitrogen vapour for 10 min and then plunged into liquid nitrogen for storage. It was observed that the progressive motility (%) decreased significantly (P < 0.01) in cryopreserved semen (43.3 ± 4.1) compared with fresh samples (76.6 ± 3.3). The percentages of live spermatozoa (P < 0.01) and spermatozoa with intact acrosome (P < 0.05) also decreased significantly in cryopreserved semen (54.0 ± 3.3 and 64.6 ± 5.3) compared with fresh samples (79.3 ± 2.6 and 85.3 ± 1.8). Simultaneously, the total morphological abnormality (%) was found to be significantly (P < 0.01) higher in cryopreserved samples (15.46 ± 2.68) than in fresh semen (3.85 ± 0.63). A total of three mithun cows were inseminated using the cryopreserved semen. All the cows conceived following insemination and gave birth to healthy calves. The study revealed that mithun semen can be cryopreserved efficiently using tris-egg yolk-glycerol diluent, which can be further used for artificial insemination.

11.
Trop Biomed ; 23(2): 156-62, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17322817

RESUMO

This study reports the knowledge and perceptions of the people with regard to cause and transmission of chronic forms of lymphatic filariasis (LF) and its elimination programme during mass drug administration (MDA) under the programme to eliminate LF in an urban area of Orissa, India. The paper is based on both quantitative and qualitative surveys undertaken before and after the first MDA among different socio-economic strata of the urban area. The data revealed that the urban residents are aware of the chronic forms of LF and also felt that LF is a problem in their area. But most of them do not know the role of mosquitoes in the transmission of the disease. A few people explained the association between LF and hydrocele, and the role of mosquitoes. In the present study, it is observed that poor knowledge about LF is highly influenced by socioeconomic conditions. People from lower economic category were least aware of the cause of both lymphoedema and hydrocele. However, knowledge in some issues with regards to the disease and the awareness on MDA have increased significantly after MDA.


Assuntos
Filariose Linfática/epidemiologia , Filariose Linfática/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde , Adulto , Animais , Coleta de Dados , Filariose Linfática/transmissão , Feminino , Filaricidas/uso terapêutico , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , População Urbana
13.
Protein Eng Des Sel ; 17(1): 57-66, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14985538

RESUMO

The limited throughput, scalability and high cost of protein purification by chromatography provide motivation for the development of non-chromatographic protein purification technologies that are cheaper and easier to implement in a high-throughput format for proteomics applications and to scale up for industrial bioprocessing. We have shown that genetic fusion of a recombinant protein to an elastin-like polypeptide (ELP) imparts the environmentally sensitive solubility property of the ELP to the fusion protein, and thereby allows selective separation of the fusion protein from Escherichia coli lysate by aggregation above a critical temperature (T(t)). Further development of ELP fusion proteins as widely applicable purification tools necessitates a quantitative understanding of how fused proteins perturb the ELP T(t) such that purification conditions (T(t)) may be predicted a priori for new recombinant proteins. We report here the effect that fusing six different proteins has on the T(t) of an ELP. A negative correlation between T(t) and the fraction hydrophobic surface area on the fused proteins was observed, which was determined from computer modeling of the available three-dimensional structure. The thermally triggered aggregation behavior of ELP-coated, functionalized gold colloids as well as ligand binding to the tendamistat-ELP fusion protein support the hypothesis that hydrophobic surfaces in molecular proximity to ELPs depress the ELP T(t) by a mechanism analogous to hydrophobic residue substitution in the ELP repeat, Val-Pro-Gly-Xaa-Gly.


Assuntos
Peptídeos/química , Engenharia de Proteínas/métodos , Proteínas Recombinantes de Fusão/química , Sequência de Aminoácidos , Bases de Dados como Assunto , Escherichia coli/metabolismo , Coloide de Ouro/química , Ligantes , Modelos Moleculares , Dados de Sequência Molecular , Plasmídeos/metabolismo , Conformação Proteica , Dobramento de Proteína , Homologia de Sequência de Aminoácidos , Solubilidade , Ressonância de Plasmônio de Superfície , Temperatura , Termodinâmica
14.
Arch Virol ; 147(6): 1173-87, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12111427

RESUMO

The complete genomic sequences of two geographically distinct isolates of rice tungro bacilliform virus (RTBV) from India were determined. Both the sequences showed equal divergence from previously reported Southeast Asian isolates. Numerous insertions, deletions and substitutions, mostly in the intergenic regions, were found. The genome sizes were 7907 and 7934 bp respectively, 95 and 68 residues short of an infectious clone reported earlier. Between them, both the isolates showed high homology all along the genome, except for a 30-nucleotide insertion/deletion close to the 3' end of ORF III in one of them. Both the isolates indicated an unconventional start codon in ORF I, similar to the type isolate. In addition, as novel features, both the Indian isolates showed an unconventional start codon for ORF IV. Considering the low amounts of genome variability noticed in other RTBV isolates, the Indian isolates show that they have diverged sufficiently from the rest and should be considered belonging to a distinct strain.


Assuntos
Badnavirus/classificação , Badnavirus/genética , Genoma Viral , Oryza/virologia , Análise de Sequência de DNA , Sequência de Aminoácidos , Badnavirus/química , Clonagem Molecular , DNA Intergênico/genética , Índia , Dados de Sequência Molecular , Fases de Leitura Aberta/genética , Filogenia , Doenças das Plantas/virologia , Mapeamento por Restrição
15.
J Indian Med Assoc ; 100(8): 522-3, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12675187

RESUMO

Though abdominal tuberculosis is fairly common in our country, incidence of tuberculous hepatitis is rare. The authors reported a case who presented to the surgical OPD of the NRS Medical College, Calcutta with complaints of right upper quadrant abdominal pain, flatulent dyspepsia, nausea and occasional vomiting. Ultrasonography (USG) revealed fibrotic gall bladder without any calculus suggesting chronic acalculus cholecystitis. On exploration of the abdomen, the gall bladder was found to be fibrotic and thickened without any calculus. Multiple scarred nodules of different sizes were found in the liver. Cholecystectomy was done and a scarring nodule from the liver was taken for histopathological examination which revealed a tuberculous granuloma. Histopathology of the gall bladder showed cholesterosis. The patient responded to antituberculous drugs.


Assuntos
Colecistite/diagnóstico , Tuberculose Hepática/diagnóstico , Antituberculosos/uso terapêutico , Colecistectomia , Colecistite/cirurgia , Diagnóstico Diferencial , Feminino , Humanos , Pessoa de Meia-Idade , Tuberculose Hepática/tratamento farmacológico
18.
J Indian Med Assoc ; 99(6): 328, 330, 334, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11678622

RESUMO

A case of obstructive jaundice in a 55-year-old male patient is reported. Ultrasonography in the case showed a space occupying lesion proximal to porta. Endoscopic retrograde cholangiopancreatography (ERCP) showed complete occlusion of bile duct near porta. The patient was operated upon and the growth was totally excised. The biliary tract was reconstructed by a Roux-en-Y hepaticojejunostomy. The anastomosis was stented in the right and left hepatic ducts and the distal ends were brought out of the abdomen and fixed to the skin. Postoperative recovery was uneventful and the tubes were clamped after 2 weeks. Regular follow-up clinically and radiologically for 3 months showed no recurrence. The tubes were removed after 3 months. The patient is well for last one and half years without any complaint.


Assuntos
Adenocarcinoma/cirurgia , Neoplasias dos Ductos Biliares/cirurgia , Adenocarcinoma/diagnóstico , Anastomose em-Y de Roux , Neoplasias dos Ductos Biliares/diagnóstico , Colangiopancreatografia Retrógrada Endoscópica , Humanos , Jejuno/cirurgia , Masculino , Pessoa de Meia-Idade , Stents
19.
J Am Chem Soc ; 123(34): 8197-202, 2001 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-11516269

RESUMO

The change in optical properties of colloidal gold upon aggregation has been used to develop an experimentally convenient colorimetric method to study the interfacial phase transition of an elastin-like polypeptide (ELP), a thermally responsive biopolymer. Gold nanoparticles, functionalized with a self-assembled monolayer (SAM) of mercaptoundecanoic acid onto which an ELP was adsorbed, exhibit a characteristic red color due to the surface plasmon resonance (SPR) of individual colloids. Raising the solution temperature from 10 degrees C to 40 degrees C thermally triggered the hydrophilic-to-hydrophobic phase transition of the adsorbed ELP resulting in formation of large aggregates due to interparticle hydrophobic interaction. Formation of large aggregates caused a change in color of the colloidal suspension from red to violet due to coupling of surface plasmons in aggregated colloids. The surface phase transition of the ELP was reversible, as seen from the reversible change in color upon cooling the suspension to 10 degrees C. The formation of colloidal aggregates due to the interfacial phase transition of adsorbed ELP was independently verified by dynamic light scattering of ELP-modified gold colloids as a function of temperature. Colloidal SPR provides a simple and convenient colorimetric method to study the influence of the solution environment, interfacial properties, and grafting method on the transition properties of ELPs and other environmentally responsive polymers at the solid-water interface.


Assuntos
Elastina/química , Coloide de Ouro/química , Adsorção , Ácidos Graxos/química , Cinética , Tamanho da Partícula , Soluções , Espectrofotometria Ultravioleta , Ressonância de Plasmônio de Superfície/métodos , Propriedades de Superfície , Água/química
20.
Arch Biochem Biophys ; 388(2): 243-52, 2001 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-11368161

RESUMO

This report characterizes the influence of a pharmacological concentration of estradiol on growth arrest and cell death in MCF-7 breast tumor cells, with a focus on elements of the Rb-E2F cell-cycle regulatory pathway. Continuous exposure of MCF-7 breast tumor cells to 100 microM estradiol produces a marked reduction in the G1 and S phase populations and a corresponding increase in the G2/M population within 24 h; after 48 h, accumulation of cells in G1 becomes evident while after 72 h the cells appear to be equally distributed between the G1 and G2/M phases. The accumulation of cells in G1 is temporally associated with dephosphorylation of the Rb protein and suppression of E2F activity. Estradiol also produces an initial burst of cell death with loss of approximately 40% of the tumor cell population within 24 h; however, there is no tangible evidence for the occurrence of apoptosis based on terminal transferase end-labeling of DNA, DNA fragmentation analysis by alkaline unwinding, cell-cycle analysis or cell morphology. In addition to the lack of caspase-3 in MCF-7 cells, the absence of apoptosis could be related, at least in part, to the fact that estradiol promotes a rapid reduction in levels of the E2F-1 and Myc proteins. Overall, these studies are consistent with the concept that alterations in the levels and/or activity of the E2F family of proteins as well as proteins interacting with the E2F family may influence the nature of the antiproliferative and cytotoxic responses of the breast tumor cell.


Assuntos
Apoptose , Proteínas de Transporte , Proteínas de Ciclo Celular , Estradiol/farmacologia , Proteína do Retinoblastoma/metabolismo , Fatores de Transcrição/antagonistas & inibidores , Proteínas Supressoras de Tumor , Neoplasias da Mama , Divisão Celular/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p21 , Inibidor de Quinase Dependente de Ciclina p27 , Ciclinas/metabolismo , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição E2F , Fator de Transcrição E2F1 , Fator de Transcrição E2F4 , Expressão Gênica/efeitos dos fármacos , Humanos , Proteínas Associadas aos Microtúbulos/metabolismo , Fosforilação/efeitos dos fármacos , Proteína 1 de Ligação ao Retinoblastoma , Fator de Transcrição DP1 , Fatores de Transcrição/metabolismo , Fatores de Transcrição/fisiologia , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/metabolismo
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