RESUMO
Unclassified sex cord/gonadal stromal tumors (SCSTs) composed predominantly of spindle cells are rare. Very few cases have been documented to date. Here, we report a case of "pure" spindle cell tumor of the left testis in a 83-year old man whose morphological and immunohistochemical findings were consistent with a diagnosis of unclassified SCST and review the literature. Owing to the spindle cell pattern, the differential diagnosis with other benign and malignant spindle cell lesions is discussed.
Assuntos
Tumores do Estroma Gonadal e dos Cordões Sexuais/diagnóstico , Neoplasias Testiculares/diagnóstico , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Humanos , Masculino , Tumores do Estroma Gonadal e dos Cordões Sexuais/patologia , Neoplasias Testiculares/patologia , Testículo/patologiaRESUMO
Iron is an essential nutrient for most living organisms. To acquire iron from their environment, Gram-negative bacteria use TonB-dependent transporters that bind host proteins at the bacterial surface and transport iron or heme to the periplasm via the Ton machinery. TonB-dependent transporters are barrel-shaped outer membrane proteins with 22 transmembrane domains, 11 surface-exposed loops, and a plug domain that occludes the pore. To identify key residues of TonB-dependent transporters involved in hemoglobin binding and heme transport and thereby locate putative protective epitopes, the hemoglobin receptor of Haemophilus ducreyi HgbA was used as a model of iron/heme acquisition from hemoglobin. Although all extracellular loops of HgbA are required by H. ducreyi to use hemoglobin as a source of iron/heme, we previously demonstrated that hemoglobin binding by HgbA only involves loops 5 and 7. Using deletion, substitution, and site-directed mutagenesis, we were able to differentiate hemoglobin binding and heme acquisition by HgbA. Deletion or substitution of the GYEAYNRQWWA region of loop 5 and alanine replacement of selected histidines affected hemoglobin binding by HgbA. Conversely, mutation of the phenylalanine in the loop 7 FRAP domain or substitution of the NRQWWA motif of loop 5 significantly abrogated utilization of heme from hemoglobin. Our findings show that hemoglobin binding and heme utilization by a bacterial hemoglobin receptor involve specific motifs of HgbA.
Assuntos
Proteínas da Membrana Bacteriana Externa/metabolismo , Haemophilus ducreyi/metabolismo , Heme/metabolismo , Hemoglobinas/metabolismo , Proteínas da Membrana Bacteriana Externa/química , Proteínas da Membrana Bacteriana Externa/genética , Haemophilus ducreyi/genética , Mutagênese Sítio-Dirigida , Ligação Proteica , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Homologia de Sequência de AminoácidosRESUMO
Rock varnish from Arizona's Whipple Mountains harbors a microbial community containing about 10(8) microorganisms g(-1) of varnish. Analyses of varnish phospholipid fatty acids and rRNA gene libraries reveal a community comprised of mostly Proteobacteria but also including Actinobacteria, eukaryota, and a few members of the Archaea. Rock varnish represents a significant niche for microbial colonization.
Assuntos
Ecossistema , Sedimentos Geológicos/microbiologia , Actinobacteria/classificação , Actinobacteria/genética , Actinobacteria/isolamento & purificação , Archaea/classificação , Archaea/genética , Archaea/isolamento & purificação , Biodiversidade , California , Células Eucarióticas , Dados de Sequência Molecular , Filogenia , Proteobactérias/classificação , Proteobactérias/genética , Proteobactérias/isolamento & purificação , RNA Arqueal/genética , RNA Arqueal/isolamento & purificação , RNA Bacteriano/genética , RNA Bacteriano/isolamento & purificação , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/isolamento & purificaçãoRESUMO
Motor neurons project onto specific muscles with a distinct positional bias. We have previously shown using electrophysiological techniques that overexpression of ephrin-A5 degrades this topographic map. Here, we show that positional differences in axon terminal areas, an entirely different parameter of neuromuscular topography, are also eliminated with ephrin-A5 overexpression. Therefore, we now have both morphological and electrophysiological approaches to explore the mechanisms of neuromuscular topography.
Assuntos
Efrina-A5/biossíntese , Músculo Esquelético/crescimento & desenvolvimento , Músculo Esquelético/inervação , Potenciais de Ação/fisiologia , Animais , Eletrofisiologia , Efrina-A5/genética , Efrina-A5/fisiologia , Genótipo , Camundongos , Camundongos Endogâmicos C57BL , Terminações Pré-Sinápticas/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
In order to assess left ventricular function in adults and children with ostium secundum atrial septal defect (ASD), 42 patients were examined by hemodynamic and angiocardiographic techniques. Patients were divided into three groups: Group I, 18 patients (mean age 42 years) with ASD; Group II, 14 patients (mean age 9 years) with ASD; Group III, 10 patients without cardiopathies who represented the control group. The following parameters of ventricular function were assessed: left ventricular end diastolic volume, global and regional left ventricular ejection fraction, left ventricular telediastolic pressure, mean pulmonary artery pressure, the ratio between pulmonary flow and systemic flow (QP/QS). Group I patients showed higher values of left ventricular end diastolic pressure and mean pulmonary artery pressure (16 +/- 0.6 mmHg; 33 +/- 1.5 mmHg) in relation to those of Group II (5.1 +/- 0.4 mmHg; 14 +/- 1.4 mmHg) and Group III (8.1 +/- 0.5 mmHg; 18 +/- 1.6 mmHg). In both cases the difference was statistically significant (p less than 0.001). A significant difference (p less than 0.05) was also noted in the incidence of mitral valve prolapse between patients in Group I and II. There was no significant difference (p = NS) however, between overall ejection fraction values in the three groups of patients; a lower regional ejection fraction (postero-basal segment) was recorded in Group I patients with mitral valve prolapse in comparison to patients in the other two groups (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
