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1.
ESMO Open ; 6(6): 100329, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34896697

RESUMO

BACKGROUND: Physician-assisted suicide (PAS) is a controversial practice and regulatory frameworks differ regarding assigned physicians' roles. This study explores clinical experience and views of German oncologists concerning ethically and legally relevant aspects of PAS after change of the law. MATERIALS AND METHODS: An online survey was conducted among members of the German Society of Haematology and Medical Oncology (DGHO) in March 2021. Descriptive analysis, bivariate and multivariable logistic regression of quantitative data on determinants related to (un)willingness to assist with suicide as well qualitative analysis of free-text comments were carried out. RESULTS: Seven hundred and forty-five of 3588 DGHO members responded (20.8%). Of these, 29.9% reported requests for a lethal drug and 3.0% (n = 22) reported to have assisted with suicide. Almost half of them (47.0%, n = 350) objected to providing PAS, whereas 45.9% indicated a willingness at least under certain conditions. Of those respondents who did not object to PAS, 25.4% would also consider assistance if those willing to die had a psychiatric disease and 10.2% if requestors had no disease at all. A majority viewed a role for physicians regarding different tasks associated with assisted suicide. Respondents with <10 years of professional experience, working in hospital with religious affiliation and with subspecialisation in palliative care were significantly less frequently willing to assist suicide. CONCLUSIONS: Respondents are divided in their personal attitudes towards PAS but a majority supports involvement of physicians regarding different tasks related to assisted suicide. Data about the practice and envisaged professional role may inform development of an acceptable ethico-legal framework for a controversial practice.


Assuntos
Hematologia , Oncologistas , Suicídio Assistido , Atitude do Pessoal de Saúde , Humanos , Oncologia , Suicídio Assistido/psicologia
2.
BMC Public Health ; 19(1): 855, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31262273

RESUMO

BACKGROUND: According to internal observations within a German shipping company, obvious risk-behaviour persists among the crew members coming from the Pacific Island State of Kiribati and representing a large part of the crew aboard merchant vessels of this company. These observations were related to excessive eating habits. This study aims to assess the cardiovascular risk among seafarers and to compare lifestyle factors between Kiribati and European crew members. METHODS: In the present maritime field study 81 sailors (48 Kiribati, 33 European, average age at 38.9 and 36.8 years respectively) were examined from April until August 2014 aboard four container ships crossing the Atlantic Ocean (participation rate of 90.9%). RESULTS: Based on the number of established risk factors, 35.4% of the Kiribati and 16.7% of the European crew members were regarded as a high risk group for cardiovascular diseases. The HDL-values of Kiribati were found to be considerably lower (34.9 mg/dl) than the references values given by the WHO and in comparison to the European crew members (44.8 mg/dl) (p = 0.002). 91.7% of Kiribati and 51.5% of European participants were found to be overweight according to WHO-criteria - with a mean Body Mass Index (BMI) of 30.3 kg/m2 and 25.6 kg/m2 (p <  0.001). Regarding lifestyle factors Kiribati often claimed to eat significantly larger amounts of food aboard while most European sailors stated to eat less or about the same during their shipboard stay (p = 0.017). Daily sleeping hours were slight on both sides; however with a mean of 5.2 h a day Kiribati crew members had significant fewer sleep (p = 0.038). The examined Kiribati sailors had a mean increase in weight of 6 kg over a 12 months period of observation. CONCLUSIONS: In total the compiled data points towards a higher risk of cardiovascular diseases particularly due to alimentary habits within the Kiribati crew members. The distinct weight-gain measured among the Kiribati in spite of higher energy consumption levels at sea is alarming. Thus, the results of this study confirm the necessity of health-improving interventions aboard cargo vessels.


Assuntos
Doenças Cardiovasculares/epidemiologia , Estilo de Vida , Militares/psicologia , Adulto , Europa (Continente)/epidemiologia , Humanos , Masculino , Micronésia/epidemiologia , Pessoa de Meia-Idade , Militares/estatística & dados numéricos , Projetos Piloto , Prevalência , Fatores de Risco , Adulto Jovem
3.
Int Arch Occup Environ Health ; 88(6): 751-7, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25618579

RESUMO

PURPOSE: This study aims to compare the hospitalization of German fishermen employed on German-flagged fishing vessels with that of the general German population in consideration of differences between coastal and deep sea fishery. METHODS: By means of a database from the health insurance company for seafarers, diagnoses of German fishermen treated in German hospitals were determined from January 1997 to December 2007. Compared with the general German population, the fishermen's risk for specific diseases leading to hospitalization was calculated as standardized hospitalization ratio (SHR). RESULTS: Compared with the German reference population, German fishermen showed a considerably high SHR for malignant neoplasms at all sites (SHR 1.46; 95% CI 1.37-1.56), for respiratory cancer, and for non-Hodgkin lymphoma (NHL). Furthermore, they had more often been hospitalized due to diabetes mellitus, diseases of the respiratory and digestive systems as well as due to injury and poisoning. The risk for respiratory cancer and NHL among coastal fishermen exceeded that of deep sea fishermen, whereas the latter displayed a considerably higher SHR for diabetes mellitus, diseases of the respiratory system and metabolic and nutritional disorders. In contrast, the SHR for hypertensive and ischemic heart diseases was decreased among deep sea fishermen. Less qualified deep sea fishermen displayed a considerably higher SHR for malignant neoplasms at all sites than more highly qualified ones. CONCLUSIONS: Fishery is still an occupation which poses a high risk for malignant neoplasms and injuries. This is likely due to lifestyle and work-related factors. Further studies are needed to evaluate the different working and living conditions of coastal and deep sea fishermen.


Assuntos
Pesqueiros/estatística & dados numéricos , Hospitalização/estatística & dados numéricos , Doenças Profissionais/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bases de Dados Factuais , Pesqueiros/métodos , Alemanha/epidemiologia , Humanos , Seguro Saúde/estatística & dados numéricos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Doenças Profissionais/etiologia , Oceanos e Mares/epidemiologia , Fatores de Risco , Navios , Adulto Jovem
4.
Arch Dermatol Res ; 305(9): 787-96, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23818098

RESUMO

The aim of this study was to assess the prevalence of UV-induced actinic keratosis and further skin lesions. A newly developed questionnaire about lifetime UV radiation exposure was completed by 514 seafarers. An experienced dermatologist inspected the whole-body skin status of all participants. The questionnaire revealed a pre-employment UV radiation exposure in 104 seafarers, sunbed use in 26 subjects and a median work-related UV radiation exposure at sea of 20 years. The diagnosis of actinic keratoses was made in 94 seafarers and the clinical diagnosis of skin cancers in 48 seafarers (28 basal cell carcinoma, 11 squamous cell carcinoma, 9 malignant melanoma). After age standardisation according to a European reference population, the male European seafarers in this study had a 1.80-fold increased risk of actinic keratosis. Actinic keratoses [OR 1.03 (1.01-1.05)] and squamous cell carcinoma [OR 1.07 (1.01-1.13)] were related to the duration of seafaring time in years. A significant association was also found between actinic keratosis/squamous cell carcinoma and sunlight exposure during home leave [OR 1.67 (1.03-2.81) and OR 6.19 (1.18-32.40)]. Furthermore, the engine room personnel-especially the technical officers-were at higher risk of developing actinic keratosis. Due to the high prevalence of actinic keratosis especially among older seafarers with fair skin, with longer duration of seafaring employment at sea and with higher UV exposure during home leave, more intensive advice should be given on sun protection both at sea and ashore.


Assuntos
Ceratose Actínica/epidemiologia , Exposição Ocupacional , Neoplasias Cutâneas/epidemiologia , Raios Ultravioleta/efeitos adversos , Adulto , Carcinoma Basocelular/diagnóstico , Carcinoma Basocelular/epidemiologia , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/epidemiologia , Feminino , Humanos , Ceratose Actínica/diagnóstico , Masculino , Melanoma/diagnóstico , Melanoma/epidemiologia , Pessoa de Meia-Idade , Prevalência , Risco , Neoplasias Cutâneas/diagnóstico , Luz Solar/efeitos adversos , Inquéritos e Questionários , Melanoma Maligno Cutâneo
5.
Unfallchirurg ; 108(6): 445-50, 2005 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-15918032

RESUMO

The treatment of enchondroma in long tubular bones has been the subject of controversial discussions for several years. Whereas secondary malignancy is very rare when the enchondroma is located in a hand, a position near to the trunk represents a high risk of transformation into a chondrosarcoma. For an enchondroma in long tubular bones, authors recommend a whole variety of approaches ranging from regular controls to radical en bloc resection. Between 1989 and 2001 we followed a concept of intralesional resection and cement filling. After an interval without recurrences, the cement was extracted and replaced by a spongiosaplasty. Of 16 patients 12.5% suffered from an intralesional fracture in the course of the treatment, and 25% complained of persistent pain and loss of function after surgery. These complications led us to change our concept. Though there were two cases of secondary transformation into chondrosarcoma G1, we now prefer to keep the patients under close clinical and radiological control without performing surgery.


Assuntos
Cimentos Ósseos/uso terapêutico , Neoplasias Ósseas/terapia , Condroma/terapia , Fixação de Fratura/métodos , Fraturas Ósseas/etiologia , Fraturas Ósseas/terapia , Osteotomia/métodos , Adolescente , Adulto , Idoso , Cimentos Ósseos/efeitos adversos , Neoplasias Ósseas/complicações , Condroma/complicações , Feminino , Fixação de Fratura/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Osteotomia/efeitos adversos , Dor/etiologia , Dor/prevenção & controle , Recuperação de Função Fisiológica , Estudos Retrospectivos , Resultado do Tratamento
6.
Sportverletz Sportschaden ; 19(1): 37-40, 2005 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-15776328

RESUMO

INTRODUCTION: Differentiation between malignant bone tumors and tumor-like lesions after repetitive microtrauma following sport activities can be difficult just using radiographic methods. METHODS: We present the case of a fifteen year old karate fighter, who was examined by imaging diagnostics because of a progressive swelling and pain in the distal right forearm. RESULTS: A tumor-like appearance with bone mass formation in the x-ray, an enhancement in the surrounding tissue shown in the MRI and an increased activity in the bone scintigraphy made the diagnosis of an osteosarcoma very likely. Blood tests were not helpful. Only the evaluation of a bone biopsy could demonstrate hypertrophic reparative bone formation after multiple osseous microtrauma. Cast immobilisation reduced the osseous alteration. With the start of the training the swelling reappeared again but then finally vanished after modifying the training technique. DISCUSSION: The case demonstrates that even modern imaging techniques cannot always distinguish between tumor and tumor-like lesions caused by sports. It also stresses the importance of a correct technique in sports like karate.


Assuntos
Traumatismos do Braço/etiologia , Neoplasias Ósseas/diagnóstico , Artes Marciais/lesões , Osteossarcoma/diagnóstico , Rádio (Anatomia)/lesões , Ulna/lesões , Adolescente , Traumatismos do Braço/diagnóstico , Biópsia , Neoplasias Ósseas/diagnóstico por imagem , Diagnóstico Diferencial , Humanos , Hipertrofia , Imobilização , Imageamento por Ressonância Magnética , Masculino , Osteomielite/diagnóstico , Osteossarcoma/diagnóstico por imagem , Cintilografia , Rádio (Anatomia)/patologia , Tomografia Computadorizada por Raios X , Ulna/patologia
7.
Diagn Mol Pathol ; 9(3): 158-64, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10976723

RESUMO

Cytokines such as tumor necrosis factor (TNF)-alpha and Interleukin (IL)-10 play significant roles in autoimmunity and transplantation tolerance. Allelic polymorphisms that occur in the regulatory regions of these cytokine genes are closely associated with acute and chronic transplant rejection. The presence of a G-to-A polymorphism at position -308 in the promoter region of the TNF-alpha gene can increase transcription six- to sevenfold. Likewise, the G-A polymorphism at position -1082 of the IL-10 promoter results in lower levels of IL-10 protein. Accordingly, a genotype that dictates the production of high levels of TNF-alpha with low IL-10 capabilities is most likely to generate an inflammatory environment that is less receptive to the transplant. The potential for determining a patient's haplotype before transplantation may be an effective way of monitoring the post-transplant status of such patients. A variety of methodologies that address the detection of mutations have been used both in research and clinical diagnostic tests. This study analyzes the genetic variations in cytokines using two methodologies: the traditional allele-specific oligonucleotide (ASO) polymerase chain reaction (PCR) and the newer and more flexible Invader technology. The sensitivity and specificity of the Invader assay for simultaneous investigation of multiple targets makes it a useful tool in such analyses.


Assuntos
Alelos , Interleucina-10/genética , Polimorfismo de Fragmento de Restrição , Regiões Promotoras Genéticas/genética , Fator de Necrose Tumoral alfa/genética , DNA/genética , Eletroforese em Gel de Poliacrilamida , Endodesoxirribonucleases/metabolismo , Genótipo , Humanos , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade , Método Simples-Cego , Especificidade por Substrato
8.
Electrophoresis ; 20(6): 1211-23, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10380761

RESUMO

We have generated a collection of clones containing single point mutations within the exon 5-9 hot spot regions of the p53 gene by using polymerase chain reaction (PCR) to amplify select regions of the gene from characterized cell lines. These clones were then used to address the sensitivity of mutation detection using slab-gel single-strand conformation polymorphism (SSCP) and Cleavase fragment length polymorphism (CFLP) assay systems. Both methods exhibited high sensitivities for the detection of mutations in cloned p53 mutations in this study: 97% for CFLP and 94% for SSCP. In addition to resulting in higher sensitivity of mutation detection, CFLP has the capability to analyze longer fragments. In this study, CFLP identified five intronic mutations which were not investigated in the exon-specific SSCP assay. These results agree with those found elsewhere and demonstrate that CFLP scanning can have practical advantages when used for the identification of sequence alterations within the p53 gene.


Assuntos
Genes p53 , Mutação , Reação em Cadeia da Polimerase/métodos , Polimorfismo Conformacional de Fita Simples , Humanos , Plasmídeos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Análise de Sequência de DNA/métodos
9.
Arch Orthop Trauma Surg ; 116(1-2): 41-5, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9006764

RESUMO

Analysis of the mechanisms of loosening of cemented stems by radiological long-term follow-up in 129 cases. The most important finding was the failure of the cement-metal interface (29.5%), which was correlated significantly with osteolysis (31%). This suggests that the polyethylene debris reaches the bone through defects in the cement mantle (76.7%). In fact, the appearance of cement defects matches the number of identified osteolyses. This study shows that no permanent fixation can be achieved by the surface roughness of 2.0 microns Ra tried herein.


Assuntos
Prótese de Quadril , Adulto , Cimentação , Humanos , Metilmetacrilatos/uso terapêutico , Desenho de Prótese , Falha de Prótese , Estudos Retrospectivos
10.
Ann Hematol ; 73(3): 121-6, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8841099

RESUMO

A retrospective study was carried out to determine the diagnostic and prognostic value of the soluble form of the embryonal neural cell adhesion molecule NCAM (CD56) in paraproteinemia. NCAM, beta 2-microglobulin, and interleukin-6 levels were measured in the sera of 170 patients with paraproteinemia. Of these, 125 had multiple myeloma, 20 Waldenström's disease, and 25 monoclonal gammopathy of unknown significance. Serum NCAM proved superior to beta 2-microglobulin and interleukin-6 in distinguishing multiple myeloma from paraproteinemias of various causes, with a high specificity of 95.5% in detecting multiple myeloma, although with a low sensitivity of 40%. In multiple myeloma NCAM is significantly correlated with beta 2-microglobulin, paraproteinemia, and low albumin levels. For the determination of tumor load beta 2-microglobulin levels accord best with the Salmon and Durie classification scheme. When patients are grouped according to their clinical course, the disease development is reflected better by NCAM than by beta 2-microglobulin or interleukin-6. Survival data indicate that all three markers have prognostic potential. Prognostic accuracy with respect to overall survival is best with beta 2-microglobulin.


Assuntos
Antígeno CD56/análise , Mieloma Múltiplo/diagnóstico , Mieloma Múltiplo/imunologia , Biomarcadores Tumorais , Diagnóstico Diferencial , Feminino , Humanos , Interleucina-6/sangue , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/sangue , Paraproteinemias/sangue , Paraproteinemias/diagnóstico , Paraproteinemias/imunologia , Prognóstico , Estudos Retrospectivos , Solubilidade , Microglobulina beta-2/análise
11.
Leuk Lymphoma ; 20(5-6): 389-95, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8833394

RESUMO

The Neural Cell Adhesion Molecule NCAM is a membrane glycoprotein and belongs to the immunoglobulin superfamily. It is expressed on neural cells as well as on various neuroendocrine tumors and can be detected in sera of patients with small cell lung cancer. Its role is attributed to tumor invasion and formation of metastases. Malignant plasma cells and a subset of plasma cells from patients with monoclonal gammopathy exhibit surface expression of NCAM whereas normal plasma cells do not express NCAM. Expression as measured by flow cytometry using anti-CD56 antibodies does not seem to correlate with clinical course, however leukemic myelomas and myeloma cell lines tend to loose NCAM surface expression. An isoform of NCAM which is rich in polysialic acids and characteristic for embryonal NCAM (eNCAM) has been shown to be elevated in sera of patients with multiple myeloma using a chemiluminescence immunoassay. Patients with progressive myeloma tend to have high serum NCAM levels above the normal range of 20 U/ml. Analysis of 125 myeloma patients suggest that serum NCAM is a valuable parameter for tumor progression rather than tumor mass. Increase in serum NCAM may be associated with loss of adhesive function.


Assuntos
Mieloma Múltiplo/metabolismo , Proteínas de Neoplasias/fisiologia , Moléculas de Adesão de Célula Nervosa/fisiologia , Biomarcadores Tumorais , Antígeno CD56 , Adesão Celular , Cromossomos Humanos Par 11/genética , Progressão da Doença , Regulação Neoplásica da Expressão Gênica , Humanos , Mieloma Múltiplo/genética , Mieloma Múltiplo/mortalidade , Mieloma Múltiplo/patologia , Invasividade Neoplásica , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/sangue , Proteínas de Neoplasias/classificação , Proteínas de Neoplasias/genética , Estadiamento de Neoplasias , Células-Tronco Neoplásicas/metabolismo , Moléculas de Adesão de Célula Nervosa/biossíntese , Moléculas de Adesão de Célula Nervosa/sangue , Moléculas de Adesão de Célula Nervosa/classificação , Moléculas de Adesão de Célula Nervosa/genética , Plasmócitos/metabolismo , Prognóstico
12.
J Biol Chem ; 269(14): 10221-4, 1994 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-7908291

RESUMO

The Q42E mutation in the polar loop of subunit c of the Escherichia coli F1F0 ATP synthase leads to an uncoupling of H+ translocation through F0 and ATP synthesis/hydrolysis in F1. We have isolated four second-site suppressor mutants in which the coupling defect is corrected. Substitutions for Glu31 in F1 subunit epsilon were found in each suppressor mutant, where the substitutions were E31G, E31V, and E31K (the last being found twice). The different substitutions vary in effectiveness in restoring wild type growth properties in the order epsilon E31G > epsilon E31V > epsilon E31K. Biochemical properties of epsilon E31G/cQ42E and epsilon E31K/cQ42E membranes were compared. In epsilon E31G/cQ42E mutant membranes, ATP-driven H+ translocation by F1F0 and the binding and coupling of F1 to F0 showed a striking pH dependence. Near normal function was observed at pH 7.0, but function was lost at pH 7.8. The function of epsilon E31K/cQ42E membranes was much less affected by changes in pH. Relative to epsilon E31G/cQ42E membranes, the ATP-driven H+ transport function of epsilon E31K/cQ42E membranes was approximately the same at pH 7.5, greater at pH 7.8, and less at pH 7.0. The differences between mutants could be explained if cGlu42 ionized at pH 7.8 with loss of function in epsilon E31G/cQ42E membrane and a similar ionization were compensated for by the positively charged Lys in the epsilon E31K/cQ42E membrane.


Assuntos
Trifosfato de Adenosina/metabolismo , Escherichia coli/enzimologia , Hidrogênio/metabolismo , Mutação , ATPases Translocadoras de Prótons/metabolismo , Transporte Biológico , Membrana Celular/enzimologia , Escherichia coli/genética , Genes Supressores , Glutamatos/genética , Ácido Glutâmico , Óperon , ATPases Translocadoras de Prótons/genética
13.
J Biol Chem ; 269(10): 7532-7, 1994 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-8125974

RESUMO

Two substitutions were made for Arg41 in the polar loop of subunit c of the Escherichia coli F1F0 H(+)-transporting ATP synthase. The R41K and R41H mutants were initially studied by use of a plasmid carrying the complete c R41K or c R41H unc (F1F0) operon in a chromosomal strain deleted for the unc operon. The extent of F0 incorporation into membranes of these cells was quite variable, and the system was concluded to be unsuitable for biochemical characterization. Ultimately, the mutant genes were recombined into the chromosome using a novel method for the unc system. The biochemical phenotype of the chromosomally expressed mutants proved to be reproducible. The c R41H mutation causes a specific defect in assembly of F0, i.e. subunit a was not incorporated into the membrane despite near normal incorporation of subunits b and c. On the other hand, c R41K mutant F0 assembled normally in one of two background strains studied. (In the second genetic background, subunit a was inefficiently incorporated into the c R41K membrane.) In membranes prepared from a c R41K strain assembling a complete F0, R41K F0 was found to bind F1 with near normal affinity and to transport H+ at near normal rates. Although R41K F0 binds F1, F1-ATPase activity and H+ transport remained uncoupled. The uncoupling was indicated by a lack of ATP-driven H+ translocation and by the high proton permeability of membranes with F1 bound to F0. The uncoupled phenotype of the R41K mutant closely resembles that previously reported for the c Q42E mutant.


Assuntos
Arginina/metabolismo , Escherichia coli/enzimologia , ATPases Translocadoras de Prótons/metabolismo , Trifosfato de Adenosina/metabolismo , Sequência de Bases , Sítios de Ligação , Transporte Biológico , Membrana Celular/enzimologia , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Oligodesoxirribonucleotídeos , ATPases Translocadoras de Prótons/química , ATPases Translocadoras de Prótons/genética , Prótons
14.
J Biol Chem ; 266(31): 20934-9, 1991 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-1834653

RESUMO

Dicyclohexylcarbodiimide (DCCD) inhibits the activity of the F1F0-H+ ATP synthase of Escherichia coli by reacting with aspartyl 61 in subunit c of the FO sector to form a stable N-acylurea. The segment of chromosomal DNA which codes the subunits of the FO was cloned from four independently isolated DCCD-resistant mutants, and the sequence of the subunit c gene (uncE) was determined. An Ala24 to serine (A24S) substitution was found in the subunit c gene of each mutant. The A24S uncE gene was cloned into the BamHI site of a mutant derivative of plasmid pBR322. The A24S subunit c conferred DCCD resistance to a variety of recipient E. coli strains when it was overexpressed from this plasmid. A 7-base pair deletion beginning at position 132 of the plasmid vector was responsible for the observed overexpression. Hoppe et al. (Hoppe, J., Schairer, H. U., and Sebald, W. (1980) Eur. J. Biochem. 112, 17-24) had previously shown that mutation of subunit c Ile28 to threonine or valine resulted in DCCD resistance. The DCCD sensitivities of the membrane ATPase of these mutants and the A24S mutant were compared. DCCD sensitivity decreased in the order: wild-type much greater than I27V greater than I28T = A24S. The venturicidin sensitivities of wild-type and mutant membranes were also examined. The membrane ATPase of the I28T and I28V mutants was venturicidin resistant whereas the A24S substitution resulted in a hypersensitivity to inhibition by venturicidin. These results support a model in which subunit c folds in the membrane like a hairpin, where the region of residues 24-28 in transmembrane helix-1 is close to that of aspartyl 61 in transmembrane helix-2.


Assuntos
Escherichia coli/enzimologia , ATPases Translocadoras de Prótons/antagonistas & inibidores , Alanina/fisiologia , Sequência de Aminoácidos , Sequência de Bases , Análise Mutacional de DNA , DNA Bacteriano/genética , Dicicloexilcarbodi-Imida/metabolismo , Dicicloexilcarbodi-Imida/farmacologia , Resistência Microbiana a Medicamentos , Teste de Complementação Genética , Vetores Genéticos , Dados de Sequência Molecular , ATPases Translocadoras de Prótons/química , ATPases Translocadoras de Prótons/genética , Alinhamento de Sequência , Serina/fisiologia , Relação Estrutura-Atividade , Venturicidinas/farmacologia
15.
Proc Natl Acad Sci U S A ; 87(13): 4900-4, 1990 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2142302

RESUMO

The proteolipid subunit c of F1F0-type H(+)-transporting ATP synthases [ATP phosphohydrolase (H(+)-transporting), EC 3.6.1.34] contains a conserved Asp/Glu residue that is thought to function in H+ translocation. To test the importance of the position of this residue in the Escherichia coli enzyme, we used oligonucleotide-directed mutagenesis to move the carboxyl side chain from position 61 to position 58, 60, or 62. Mutant cells with these changes were incapable of growth via oxidative phosphorylation on succinate. An Asp-61----Glu mutant grew on succinate but at 50% the efficiency of wild type. Hence, even minor changes in the position of the carboxyl group can significantly reduce function. In a second approach, slow-growing revertants to an Asp-61----Gly mutant were isolated. In one such revertant, Ala-24 was changed to Asp, while the original Asp-61----Gly mutation remained unchanged. The Asp-24-Gly-61 double mutant grew on succinate at 60% the efficiency of wild type. Hence the essential carboxyl group of subunit c can function when anchored at either position 24 or position 61, and this supports the idea that these residues may neighbor each other when subunit c is folded in the membrane. The rate of ATP-driven H+ translocation by mutant membrane vesicles was estimated by the quenching of 9-amino-6-chloro-2-methoxyacridine fluorescence and corresponded to actual H+ pumping rates less than 25% that of wild type.


Assuntos
Escherichia coli/enzimologia , ATPases Translocadoras de Prótons/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Membrana Celular/enzimologia , Membrana Celular/ultraestrutura , Cromossomos Bacterianos , Escherichia coli/genética , Genes Bacterianos , Concentração de Íons de Hidrogênio , Cinética , Substâncias Macromoleculares , Dados de Sequência Molecular , Mutação , Sondas de Oligonucleotídeos , Conformação Proteica , ATPases Translocadoras de Prótons/genética
16.
Hum Genet ; 79(2): 183-5, 1988 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2839409

RESUMO

Fifteen apparently unrelated Dutch families with familial adenomatous polyposis (FAP) also known as familial polyposis coli (FPC; McKusick No. 17510) were screened for linkage with the DNA probe C11p11 localized on chromosome 5q21-22 and previously reported to be closely linked to FAP (Bodmer et al. 1987; Leppert et al. 1987). In our study C11p11 was minimally informative, which is ascribable to its low heterozygosity in the North European populations. Of the above families, 12 were investigated also for linkage with D5S37 (DNA probe Pi227). Data from 11 of them were found to be informative and showed that FAP is closely linked to D5S37 previously localized on chromosome 5q21 (peak lod score 7.85 at a recombination fraction of 0.048 with 95% probability limits 0.005-0.145). Results discussed below indicate for the first time that the most likely location of the FAP gene is in the band 5q22 very close to 5q21, if not in the transitional zone between these two bands. The probe Pi227 recognizes 4 restriction fragment length polymorphism (RFLP) sites, exhibiting a total of 9 alleles with 24 theoretically possible haplotypes in the Dutch population. Therefore, this probe appears to have potential as a generally useful predictive marker for FAP until much closer and similarly useful markers become available.


Assuntos
Polipose Adenomatosa do Colo/genética , Cromossomos Humanos Par 5 , Ligação Genética , Marcadores Genéticos , Polimorfismo Genético , Mapeamento Cromossômico , Feminino , Humanos , Masculino , Linhagem
17.
Nucleic Acids Res ; 15(22): 9365-78, 1987 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-3684597

RESUMO

We have investigated the structural gene for adenosine deaminase (ADA) in a female infant with ADA deficiency associated severe combined immune deficiency (ADA-SCID) disease and her family by DNA restriction-fragment-length analysis. In this family a new ADA-specific restriction-fragment-length variant was detected, which involves a 3.2-kb deletion spanning the ADA promoter as well as the first exon. It was found that the patient, who was born to a consanguineous couple, was homozygous and both her parents and her brother were heterozygous for the deletion. No ADA-specific mRNA could be detected by hybridization in fibroblasts derived from this patient. Thus the patient was established to be homozygous for a true null ADA allele. In the light of the apparently normal development of most tissues except the lymphoid tissue the above finding directly questions the classification of ADA as a 'housekeeping' enzyme.


Assuntos
Adenosina Desaminase/deficiência , Deleção Cromossômica , Éxons , Genes , Homozigoto , Síndromes de Imunodeficiência/genética , Nucleosídeo Desaminases/deficiência , Regiões Promotoras Genéticas , Adenosina Desaminase/sangue , Eritrócitos/enzimologia , Feminino , Humanos , Síndromes de Imunodeficiência/enzimologia , Lactente , Leucócitos/enzimologia , Masculino , RNA Mensageiro/genética , Valores de Referência , Transcrição Gênica
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