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1.
J Clin Orthop Trauma ; 10(2): 340-344, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30828205

RESUMO

BACKGROUND: Total knee replacement (TKR) is an optimal treatment for persons with severe knee joint pain and disability, who were unsuccessful with conservative management. Early mobilization can be defined as moving out of bed and/or walking quickly after the surgery for reducing the risks allied with bed rest. There is a paucity of studies on effects of early mobilization on a performance-based measure of timed up and go test (TUG), six-minute walk test (SMWT) and a self-reported disease-specific measure of a knee injury and Osteoarthritis outcome score (KOOS) following TKR. METHODS: A prospective pre-post-trial was conducted at Manipal Hospital, Bangalore, India. Participants underwent early (POD '0') mobilization on the same postoperative day within 7 h post-TKR surgery. Outcome measures were recorded by an independent blinded observer. The statistical significance level was set at 'p' value < 0.05. The difference between pre-operative and post-operative outcome measure at 1 month and 3 months post-intervention were analyzed using repeated measures of ANOVA. RESULTS: The study included a total of 78 participants (59 Females; 19 Males) and the mean age of the included participants was 64.1 ±â€¯7 years. Amongst, 78 participants, 53 underwent unilateral TKR, 25 underwent bilateral TKR. There were three dropouts in the study due to post-operative complications. Significant improvements from pre-operative to one month were observed following POD '0' mobilization on NPRS (7.35 ±â€¯1.2 to 4.3 ±â€¯1.7), SMWT (169 ±â€¯70 to 236.7 ±â€¯80.7). KOOS subscales of pain, symptom, and quality of life showed significant changes at one month and 3 months. TUG, Knee strength, Knee ROM and KOOS ADL subscale shown improvements only at 3 months post-intervention. CONCLUSION: Our study findings suggest that POD '0' (early) mobilization can result in reduced pain and an increase in walking speed at 1 month. Significant changes were observed in pain, Knee strength, Knee ROM, TUG, SMWT and KOOS subscales at 3 months following total knee replacement.

2.
IEEE Trans Vis Comput Graph ; 25(5): 1846-1854, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30762555

RESUMO

Precomputed sound propagation samples acoustics at discrete scene probe positions to support dynamic listener locations. An offline 3D numerical simulation is performed at each probe and the resulting field is encoded for runtime rendering with dynamic sources. Prior work place probes on a uniform grid, requiring high density to resolve narrow spaces. Our adaptive sampling approach varies probe density based on a novel "local diameter" measure of the space surrounding a given point, evaluated by stochastically tracing paths in the scene. We apply this measure to layout probes so as to smoothly adapt resolution and eliminate undersampling in corners, narrow corridors and stairways, while coarsening appropriately in more open areas. Coupled with a new runtime interpolator based on radial weights over geodesic paths, we achieve smooth acoustic effects that respect scene boundaries as both the source or listener move, unlike existing visibility-based solutions. We consistently demonstrate quality improvement over prior work at fixed cost.

3.
Indian J Med Microbiol ; 34(2): 173-82, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27080768

RESUMO

BACKGROUND: The ability of microorganisms to evade antibiotic pressure is challenging in healthcare as patients have little or no drug treatment options. Detection of the prevalence of antibacterial resistance pattern helps towards improved antibiotic policy and empirical treatment. OBJECTIVES: We carried out antibiogram profiling and documented the prevalence and co-prevalence of New Delhi metallo-ß-lactamase (NDM) and extended spectrum ß-lactamases (ESBL) encoding genes in urinary Escherichia coli and Klebsiella pneumonia isolates. MATERIALS AND METHODS: Antibiotic susceptibilities were tested for 241 isolates of E. coli and K. pneumoniae from urine samples collected from out- and hospitalised patients. Polymerase chain reaction (PCR) was carried out on isolates tested positive for phenotypic production of metallo-ß-lactamase and ESBL. A multiplex PCR assay was designed to detect the genes. RESULTS: Multiplex PCR assay designed had a limit of detection of 10 3 CFU/mL in vitro. NDM detected was significantly higher among K. pneumoniae compared to E. coli (69.2% vs. 18.2%; P = 0.001). Of 17, 14 NDM positive isolates also harboured ESBL genes. The co-production of CTX-M + TEM + NDM (3/9; 33.3% and 5/8; 62.5%) was most common in K. pneumoniae and E. coli, respectively while CTX-M + TEM + SHV + NDM was found in one isolate. Of the 156 phenotypically ESBL producing isolates, CTX-M, TEM and SHV was detected by PCR in 85, 53 and 24 isolates, respectively. CONCLUSION: NDM and ESBL co-producing isolates were both community (64.7%) and hospital (35.29%) acquired among E. coli. Antibiotic resistance can be effectively evaluated by a cost and time effective molecular method, such as the multiplex PCR used in this study, which complement culture and sensitivity tests.


Assuntos
Infecções Comunitárias Adquiridas/microbiologia , Infecções por Enterobacteriaceae/microbiologia , Escherichia coli/enzimologia , Klebsiella pneumoniae/enzimologia , Reação em Cadeia da Polimerase Multiplex , Infecções Urinárias/microbiologia , beta-Lactamases/genética , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Infecções Comunitárias Adquiridas/epidemiologia , Infecções por Enterobacteriaceae/epidemiologia , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Humanos , Índia , Lactente , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Prevalência , Infecções Urinárias/epidemiologia , Adulto Jovem
4.
J Viral Hepat ; 22(10): 817-27, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25720442

RESUMO

Effective recognition of viral infection and successive activation of antiviral innate immune responses are vital for host antiviral defence, which largely depends on multiple regulators, including Toll-like receptors (TLRs) and microRNAs. Several early reports suggest that specific TLR-mediated immune responses can control hepatitis B virus (HBV) replication and express differentially with disease outcome. Considering the versatile function of miR-155 in the TLR-mediated innate immune response, we aimed to study the association between miR-155 and TLRs and their subsequent impact on HBV replication using both a HBV-replicating stable cell line (HepG2.2.15) and HBV-infected liver biopsy and serum samples. Our results showed that miR-155 was suppressed during HBV infection and a subsequent positive correlation of miR-155 with TLR7 activation was noted. Further, ectopic expression of miR-155 in vitro reduced HBV load as evidenced from reduced viral DNA, mRNA and subsequently reduced level of secreted viral antigens (HBsAg and HBeAg). Our results further suggested that CCAAT/enhancer-binding protein-ß (C/EBP-ß), a positive regulator of HBV transcription, was inhibited by miR-155. Taken together, our study established a correlation between miR-155 and TLR7 during HBV infection and also demonstrated in vitro that increased miR-155 level could help to reduce HBV viral load by targeting C/EBP-ß.


Assuntos
Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Vírus da Hepatite B/imunologia , Hepatócitos/imunologia , Hepatócitos/virologia , Fígado/virologia , MicroRNAs/biossíntese , Receptor 7 Toll-Like/biossíntese , Linhagem Celular , Vírus da Hepatite B/fisiologia , Humanos , Fígado/patologia , Replicação Viral
5.
Ann Hepatol ; 11(6): 870-5, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23109450

RESUMO

BACKGROUND: The prevalence of occult HBV, defined by the presence of HBV DNA in individuals with antibodies to HBV core antigen and with absence of HBV surface antigen, but its clinical significance and virological features in HIV-infected patients is still unclear. AIM: To investigate the prevalence, clinical significance and molecular characterization of occult hepatitis B virus infection in ART-Naive HIV-positive individuals. MATERIAL AND METHODS: Among the 1077 HIV-infected patients with different risk factors for HIV infection, 297 were HBsAg-ve ART-naive, of them 112 was randomly selected for the study. HBV DNA was tested by in-house PCR and quantified by qPCR. Molecular characterization was performed by sequencing the envelope and overlapping polymerase genes. RESULTS: We found the prevalence of occult HBV to be 10.7% among a randomly selected group of HBsAg-ve/antiHBc+ve HIV-infected patients. Overall 33.9% (38 of 112) of the patients were antiHBc positive indicating exposure to HBV infection. HBV DNA was detected in 12/38 (31.5%) antiHBc positive samples and 50% of them had CD4 T cell count < 200 cells/mm(3). HCV coinfection was low (2.7%). No surrogate marker for OBI could be identified. Presence of antiHBs antibodies did not rule out OBI. Liver biopsy in six cases showed varying stages of chronic hepatitis. Several mutations were detected but not the common immune escape mutant G145R. CONCLUSION: In conclusion the prevalence of OBI was significantly high among HIV coinfected patients, which highlights the importance of HBV DNA testing in these patients and indicates need for further prospective studies in larger cohorts to assess its clinical significance.


Assuntos
Coinfecção , Infecções por HIV/epidemiologia , Antígenos do Núcleo do Vírus da Hepatite B/sangue , Vírus da Hepatite B/imunologia , Hepatite B/epidemiologia , Encaminhamento e Consulta , Adolescente , Adulto , Biomarcadores/sangue , Biópsia , Contagem de Linfócito CD4 , Distribuição de Qui-Quadrado , DNA Viral/sangue , Ensaio de Imunoadsorção Enzimática , Feminino , Infecções por HIV/diagnóstico , Hepatite B/diagnóstico , Antígenos de Superfície da Hepatite B/sangue , Vírus da Hepatite B/genética , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Mutação , Reação em Cadeia da Polimerase , Valor Preditivo dos Testes , Prevalência , RNA Viral/sangue , Análise de Sequência de DNA , Adulto Jovem
6.
J Viral Hepat ; 16(10): 749-56, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19457142

RESUMO

Hepatitis B genotype D (HBV/D) is the most widespread genotype and exists as at least five subgenotypes (HBV/D1-D5). However, little is known about the association of virological characteristics with clinical differences among HBV/D subgenotypes. To investigate the virological characteristics of these subgenotypes and their clinical implications, we selected a cohort of 109 genotype D infected individuals from the state of West Bengal, India, including 68 HBsAg positive patients and 41 with occult HBV infection. Among the HBsAg positive subjects 28 had chronic hepatitis B virus infection, 40 were asymptomatic carriers based on clinical examination, liver function test and ultrasonograph results. Overall, HBV/D1 was found in 17%, HBV/D2 in 29%, HBV/D3 in 34% and HBV/D5 in 20% of the cases. HBV/D1 was significantly associated with chronic liver disease (P = 0.01), and in this subgenotype A1896 (PreC mutations) were most common. Although BCP mutations (A/C1753 and T1762/A1764) were found to be frequently associated with HBV/D2 (33% and 33%) and D5 (47% and 59%), no apparent clinical correlation was observed. On the other hand, occult HBV infection was significantly associated with HBV/D3 infection, along with low level of BCP and PreC mutations and several non-synonymous substitutions in the catalytic reverse transcriptase (RT) domain of polymerase gene. Similar nucleotide substitutions in the surface (S) gene region were observed from both northern and eastern Indian HBV/D3 isolates. In conclusion, HBV/D subgenotypes differ in their mutational patterns in the S, polymerase and the BCP/PreC regions that may influence their clinical outcomes.


Assuntos
DNA Viral/genética , Variação Genética , Vírus da Hepatite B/classificação , Vírus da Hepatite B/isolamento & purificação , Hepatite B/epidemiologia , Hepatite B/virologia , Adolescente , Adulto , Criança , Feminino , Genótipo , Antígenos de Superfície da Hepatite B/genética , Vírus da Hepatite B/genética , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Análise de Sequência de DNA , Adulto Jovem
7.
Indian J Dermatol ; 53(4): 210-1, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19882040

RESUMO

A 39-year-old female with a pruritic verrucous plaque over dorsal aspect of great toe was treated with 4 intralesional corticosteroid injections each at an interval of 2 weeks. Three months later, she developed depigmentation at the injection site and in a network-like distribution radiating away from the site. The depigmentation corresponded to the lymphatic drainage channels of the great toe.

9.
Arch Virol ; 152(6): 1223-8, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17216140

RESUMO

The Karens, or 'old settlers', migrated from Myanmar to Andaman and Nicobar islands 80 years ago. A high HBV exposure rate among them has been reported. A study of 34 HBsAg carriers was done to investigate the origin of HBV infection among the Karens. RFLP-based genotyping was confirmed by sequencing and phylogenetic analysis. The predominance of HBV/C1/Cs suggests that they carried HBV during their migration, retained it, and in addition, acquired HBV/D2 from the people of mainland India. The reported association of HBV genotype C with disease severity thus warrants further epidemiological investigations among them and on possible spread among neighboring settlers.


Assuntos
Vírus da Hepatite B/classificação , Vírus da Hepatite B/genética , Adolescente , Adulto , DNA Viral/genética , Emigração e Imigração , Etnicidade , Evolução Molecular , Feminino , Genes Virais , Hepatite B/virologia , Vírus da Hepatite B/isolamento & purificação , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mutação , Mianmar/etnologia , Filogenia
10.
Arch Virol ; 151(8): 1499-510, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16514497

RESUMO

The Jarawas, a classical hunter-gatherer tribe of Andaman and Nicobar Islands, India, were living in isolation for several centuries. They came into contact with the civilized world recently. Serological studies carried out among them revealed that hepatitis B virus (HBV) infection is hyper-endemic. The present study was carried out to investigate the possible origin of HBV infection in Jarawas. Genotyping, RFLP analysis, sequencing, and sequence analysis revealed the prevalence of HBV genotype C, similar to genotype C detected in Thailand, Vietnam, and Myanmar. In contrast, genotype D was prevalent among other non-Jarawa tribes of the island. These data suggest that HBV infection was transmitted from Indo-China to the Andaman Islands during migration of the Jarawas many centuries ago.


Assuntos
Etnicidade , Vírus da Hepatite B/classificação , Vírus da Hepatite B/genética , Hepatite B/epidemiologia , Sequência de Aminoácidos , Genótipo , Hepatite B/virologia , Antígenos de Superfície da Hepatite B/sangue , Vírus da Hepatite B/isolamento & purificação , Humanos , Índia/epidemiologia , Dados de Sequência Molecular , Prevalência , Grupos Raciais
11.
Public Health ; 119(7): 647-54, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15925680

RESUMO

OBJECTIVES: India, with its 43 million hepatitis B virus (HBV) carriers and absence of any national immunization programme, adds a substantial number of HBV infections to the HBV carrier pool yearly. The aim of this study was to assess the spread of HBV infection in families with an infected member and to identify the family members with the highest risk of infection in our community. METHODS: A total of 937 serum samples from 215 HBV-infected cases and 722 members of their households were screened prospectively for markers of HBV by commercial enzyme-linked immunosorbent assay. RESULTS: Among family members, 140 (19.4%) were HBsAg positive and 272 (37.6%) were negative for HBsAg but positive for either anti HBc or anti HBs. There were 145 HBsAg-positive adults among the index cases whose 133 adult siblings, 59 spouses and 59 mothers participated in the study. Interestingly, 28.81% mothers and 28.57% adult siblings of these adult index cases were positive for HBsAg compared with only 8.75% of their spouses (P < 0.001). Only 15.2% of the HBsAg-positive women in the childbearing age group were found to be HBeAg positive. CONCLUSIONS: Our results suggest that intrafamilial childhood horizontal transmission is important for HBV transmission in our community, and highlight the need for screening of adult siblings and mothers of adult HBsAg carriers in addition to their spouses and children.


Assuntos
Portador Sadio/sangue , Saúde da Família , Hepatite B/epidemiologia , Programas de Rastreamento , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Análise por Conglomerados , Transmissão de Doença Infecciosa/prevenção & controle , Ensaio de Imunoadsorção Enzimática , Feminino , Hepatite B/sangue , Hepatite B/prevenção & controle , Hepatite B/transmissão , Antígenos de Superfície da Hepatite B/sangue , Humanos , Índia/epidemiologia , Lactente , Masculino , Pessoa de Meia-Idade , Mães/estatística & dados numéricos , Fatores de Risco , Irmãos , Inquéritos e Questionários
12.
Artigo em Inglês | MEDLINE | ID: mdl-15906669

RESUMO

A seroepidemiological study was conducted to determine the hepatitis B virus carrier rate and infectivity status among antenatal patients in Calcutta. Fifteen of 400 antenatal mothers (3.74%) were carriers of HBV genotype D. Four (1.0%) of them were positive for HBeAg with a high risk of transmitting infection to their babies. The presence of precore mutant HBV, which has been associated with transmission events from HBeAg mothers to their babies, was not detected in any of the HBeAg negative mothers.


Assuntos
Biomarcadores/sangue , Portador Sadio/virologia , Antígenos de Superfície da Hepatite B/sangue , Vírus da Hepatite B/genética , Vírus da Hepatite B/isolamento & purificação , Hepatite B/epidemiologia , Complicações Infecciosas na Gravidez/epidemiologia , Diagnóstico Pré-Natal/métodos , Feminino , Hepatite B/sangue , Maternidades/estatística & dados numéricos , Humanos , Técnicas Imunoenzimáticas , Índia/epidemiologia , Transmissão Vertical de Doenças Infecciosas , Reação em Cadeia da Polimerase , Gravidez , Complicações Infecciosas na Gravidez/sangue , Complicações Infecciosas na Gravidez/virologia , Estudos Soroepidemiológicos
14.
Oncogene ; 11(10): 2067-75, 1995 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-7478526

RESUMO

The mts1 gene codes for a 101 amino acid protein belonging to the S100 subfamily of Ca(2+)-binding proteins. Mts1 is overexpressed in metastatic cancers as compared to their nonmetastatic counterparts, and although mts1 is known to be involved in the metastatic phenotype (Davies et al., 1993; Grigorian et al., 1993), the role mts1 plays in this process is not clearly understood. In order to determine what role mts1 plays in the process of metastasis, we have performed transfection studies on nonmetastatic and metastatic mouse mammary adenocarcinoma cell lines, CSML0 and CSML100, respectively (Senin et al., 1983, 1984). The metastatic variant, CSML100, expresses high levels of mts1, whereas the nonmetastatic variant, CSML0, expresses almost no mts1. CSML0 cells transfected with mts1 were assessed in in vitro motility and invasion assays, as well as in vivo metastasis assays to determine the role of mts1 in these processes. Cell lines expressing mts1 display an altered morphology as well as increased motility in modified Boyden chemotaxis chambers. However, no significant increase in in vitro invasion or in in vivo metastasis was observed. Therefore, the presence of mts1 may be important for metastasis by increasing motility, but may not be sufficient for invasion in vitro or metastasis in vivo. Very low levels of type IV collagenase activities were observed in CSML0 cells and the transfectants, as opposed to the highly metastatic CSML100 cells, where high levels of type IV collagenase activities were observed. It is possible that the presence of these proteases in addition to mts1 may be responsible for the high metastatic potential of the CSML100 in vivo.


Assuntos
Adenocarcinoma/genética , Genes Supressores de Tumor/fisiologia , Neoplasias Mamárias Experimentais/genética , Adenocarcinoma/patologia , Animais , Movimento Celular/fisiologia , Colágeno , Progressão da Doença , Combinação de Medicamentos , Regulação Neoplásica da Expressão Gênica , Genes Supressores de Tumor/genética , Laminina , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Endogâmicos A , Invasividade Neoplásica/genética , Transplante de Neoplasias , Fenótipo , Proteoglicanas , Transfecção , Células Tumorais Cultivadas
15.
Injury ; 25(7): 461-4, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7960051

RESUMO

Seventy tibial shaft fractures treated by intramedullary nailing using two different techniques were compared. The first group (35 cases) was treated with a Herzog intramedullary nail following hand reaming and minimal traction. The second group (35 cases) had a Grosse and Kempf or AO nail inserted following power reaming and skeletal traction. Fracture patterns were similar in both groups. In the hand-reamed group, the mean time to union was 15.2 weeks with two delayed unions and no non-unions. In the power-reamed group, the mean time to union was 19.9 weeks with 10 delayed unions and two non-unions. These differences were statistically significant. Complications in the hand-reamed group included a Sudecks atrophy and one mal-union. In the power-reamed group, there were three transient foot drops, two compartment syndromes and one pulmonary embolus. This difference was not statistically significant. Our findings suggest that surgical technique has an important effect on the healing rates of nailed tibial shaft fractures. When intramedullary nailing is performed, minimal reaming is required and skeletal traction should be avoided if possible.


Assuntos
Fixação Intramedular de Fraturas/métodos , Consolidação da Fratura , Fraturas da Tíbia/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Pinos Ortopédicos , Síndromes Compartimentais/etiologia , Feminino , Seguimentos , Fixação Intramedular de Fraturas/efeitos adversos , Fraturas Mal-Unidas/etiologia , Fraturas não Consolidadas/etiologia , Humanos , Masculino , Pessoa de Meia-Idade
16.
Exp Parasitol ; 78(3): 253-8, 1994 May.
Artigo em Inglês | MEDLINE | ID: mdl-8162958

RESUMO

A hemolytically active component was found to be present in Leishmania donovani promastigotes for the first time. It lysed human and rabbit erythrocytes to varying degrees. The optimal pH for the activity was found to be 5.8. The rate of hemolysis was dependent on both erythrocyte and parasite concentrations. Parasites in the log phase were more effective in lysing erythrocytes than those in the stationary phase. Centrifugation at 10,000g showed major activity in the pellet fraction of the autolysate. Boiling in a water bath for 5 min reduced 98% of the hemolytic activity, which was also found to be inhibited by trypsin. The presence of such a hemolytic factor appears to be important in the nutrition of this parasite.


Assuntos
Eritrócitos/parasitologia , Hemólise , Leishmania donovani/metabolismo , Animais , Contagem de Eritrócitos , Humanos , Concentração de Íons de Hidrogênio , Cinética , Leishmania donovani/efeitos dos fármacos , Leishmania donovani/crescimento & desenvolvimento , Coelhos , Ovinos , Temperatura , Tripsina/farmacologia
17.
Proc Natl Acad Sci U S A ; 87(23): 9333-7, 1990 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1979171

RESUMO

The nucleotide and deduced amino acid sequences of the coding regions of human and rat keratinocyte transglutaminases (protein-glutamine: amine gamma-glutamyltransferase; EC 2.3.2.13) have been determined. These yield proteins of approximately 90 kDa that are 92% identical, indicative of the conservation of important structural features. Alignments of amino acid sequences show substantial similarity among the keratinocyte transglutaminase, human clotting factor XIII catalytic subunit, guinea pig liver tissue transglutaminase, and the human erythrocyte band-4.2 protein. The keratinocyte enzyme is most similar to factor XIII, whereas the band-4.2 protein is most similar to the tissue transglutaminase. A salient feature of the keratinocyte transglutaminase is its 105-residue extension beyond the N terminus of the tissue transglutaminase. This extension and the unrelated activation peptide of factor XIII (a 37-residue extension) appear to be added for specialized functions after divergence of the tissue transglutaminase from their common lineage.


Assuntos
Queratinócitos/enzimologia , Transglutaminases/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Células Cultivadas , Clonagem Molecular , Códon/genética , Biblioteca Gênica , Humanos , Dados de Sequência Molecular , Sondas de Oligonucleotídeos , Mapeamento por Restrição , Homologia de Sequência do Ácido Nucleico
18.
Biochem J ; 271(1): 25-30, 1990 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-1977383

RESUMO

The membrane-bound transglutaminase of cultured keratinocytes became radioactively labelled upon addition of [32P]Pi to the medium. Transglutaminase phosphorylation was also demonstrable using particulate material isolated from cell homogenates. Compatible with mediation of the labelling by protein kinase C, the degree of phosphorylation in intact cells was stimulated approx. 5-fold in 4 h on treatment with the tumour-promoting phorbol ester phorbol 12-myristate 13-acetate, but not by phorbol. The extent of labelling was virtually unaffected by cycloheximide inhibition of protein synthesis, indicating that it arose primarily through turnover of phosphate in the membrane-bound enzyme. Phosphoamino acid analysis detected labelling only of serine residues. Most of the label was removed by trypsin release of the enzyme from the particulate fraction of cell homogenates, which deletes a membrane anchorage region of approximately 10 kDa. Upon trypsin treatment of the enzyme after immunoprecipitation, the phosphate label was recovered in soluble peptide material with a size of several thousand Da or less. Indicative of fragmentation of the membrane anchorage region, this material was separable by h.p.l.c. into two equally labelled peptides. Moreover, when the enzyme was labelled with [3H]palmitate or [3H]myristate, the fatty-acid-labelled peptide material required non-ionic detergent for solubilization and was separable from the phosphate-labelled material by gel filtration. Phorbol ester treatment of cultured keratinocytes in high- or low- Ca2(+)-containing medium was not accompanied by an appreciable protein-synthesis-independent change in transglutaminase activity. Independent of possible alteration of the intrinsic catalytic activity of the enzyme, phosphorylation may well modulate its interaction with substrate proteins, a potential site for physiological regulation.


Assuntos
Membrana Celular/enzimologia , Queratinócitos/enzimologia , Proteína Quinase C/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Transglutaminases/metabolismo , Sítios de Ligação , Células Cultivadas , Humanos , Técnicas de Imunoadsorção , Fragmentos de Peptídeos/isolamento & purificação , Fosfatos/metabolismo , Fosforilação , Fosfosserina/metabolismo , Tripsina/metabolismo
19.
J Cell Sci ; 95 ( Pt 4): 631-8, 1990 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1974551

RESUMO

Expression of keratinocyte transglutaminase, a specific differentiation marker, has been examined by immunogold-silver cytochemistry in human epidermis and oral epithelium, and in oral mucosal hyperplasia and neoplasia. Two major findings have been obtained. First, considerable immunoreactivity was evident not only at the plasma membrane (the site of cross-linked envelope formation) but also in the cytoplasm of spinous cells, suggesting a cytoplasmic function for this transglutaminase. Staining at the cell border was seen principally in the granular layer of orthokeratinized epithelium (epidermis, hard palate), the outer spinous cells of ortho- and parakeratinized epithelium and in the suprabasal cells showing squamous differentiation in benign and malignant neoplasms. By contrast, diffuse cytoplasmic staining was observed in the upper spinous layer of the normal epithelium and benign lesions. The cytoplasmic immunoreactivity, which extended nearly to the basal layer in hyperkeratosis of the oral mucosa, was evident in two of three verrucous carcinomas examined. In keeping with their undifferentiated character, invasive nests of squamous cell carcinoma and basaloid epithelium in benign and neoplastic lesions were immunonegative for transglutaminase. The second major finding was that lesions of severe oral epithelial dysplasia, immunonegative for transglutaminase, were capable of expressing involucrin immunoreactivity, indicating an uncoupling of keratinocyte programming. These results suggest that immunogold-silver staining for transglutaminase may be useful in evaluating the degree of differentiation in benign and malignant oral epithelial proliferation.


Assuntos
Queratinócitos/enzimologia , Mucosa Bucal/enzimologia , Pele/enzimologia , Transglutaminases/biossíntese , Diferenciação Celular , Citoplasma/metabolismo , Epiderme/metabolismo , Epitélio/metabolismo , Humanos , Immunoblotting , Imuno-Histoquímica , Queratinócitos/citologia , Neoplasias Bucais/enzimologia , Precursores de Proteínas/biossíntese , Transglutaminases/análise
20.
Biochem J ; 265(2): 351-7, 1990 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-1967934

RESUMO

Human keratinocytes express a particulate transglutaminase that can be released from the membrane by limited proteolysis with trypsin or plasmin to yield a form that is congruent to 80 kDa. The enzyme from cultured cells was also releasable by endogenous proteolysis to yield a catalytically active fragment of congruent to 80 kDa. Endogenous release was strongly dependent upon temperature and Ca2+ concentration and was inhibited by iodoacetate, but not by leupeptin, antipain or phenylmethanesulphonyl fluoride. These phenomena raise the possibility of partial translocation of transglutaminase activity to the cytoplasm by proteolysis to which the enzyme is subject during terminal differentiation. In addition, hydrodynamic measurements showed that the endogenously released enzyme was monomeric in solution (79 kDa), whereas that solubilized by hydroxylamine without proteolysis appeared dimeric (190 kDa). The latter dimeric state may reflect either an altered conformation of the enzyme or post-translational modification beyond fatty acid esterification.


Assuntos
Queratinócitos/enzimologia , Transglutaminases/metabolismo , Membrana Celular/enzimologia , Células Cultivadas , Cromatografia em Gel , Fibrinolisina/farmacologia , Humanos , Recém-Nascido , Masculino , Peso Molecular , Temperatura , Transglutaminases/isolamento & purificação , Tripsina/farmacologia
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