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INTRODUCTION: Schwannomas are a group of well differentiated benign tumors originating from the Schwann cells of the peripheral nervous system. Their localization in the pelvis is very rare. Schwannomas with expansive growth can cause wide neurologic symptoms or oppression of pelvic organs. CASE REPORT: The authors present a case study of a 60-year-old woman with a large, symptomatic deep pelvic schwannoma. The patient underwent robotic-assisted surgery resulting in complete tumor extirpation. The patient's postoperative course was uneventful with a total of two hospitalization days. The diagnosis of a schwannoma was confirmed by histopathologic analysis. At 11-month follow-up surveillance the patient did not present any neurological deficit or other symptoms. CONCLUSION: Robotic-assisted surgery allows safe and effective surgical treatment in difficult-to-access anatomical areas. Magnetic resonance imaging is required for preoperative imaging of neurogenic tumors. Histological verification is not recommended in cases where evidence of a schwannoma is found. Multidisciplinary cooperation of a dedicated team experienced in minimally invasive pelvic surgery is necessary.
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Neurilemoma , Procedimentos Cirúrgicos Robóticos , Feminino , Humanos , Pessoa de Meia-Idade , Neurilemoma/diagnóstico por imagem , Neurilemoma/cirurgia , Pelve/patologia , Resultado do Tratamento , IdosoRESUMO
INTRODUCTION: The aim of this study was to evaluate a group of bariatric patients operated at the Military University Hospital in Prague during the last 10 years (20112020), in whom laparoscopic sleeve gastrectomy was performed. METHODS: Retrospective survey of the internal operation database. The search used the following combination of keywords: “sleeve“, “LSG“ and the diagnosis “E6*“. A total of 279 operated patients were enrolled. We evaluated the sex, age at the time of surgery, complications, need for drainage, weight, BMI, presence of type two diabetes mellitus and any effect of the surgery on its improvement, length of hospital stay, follow-up duration and % excess weight loss. RESULTS: A total of 279 patients, including 195 women and 84 men, underwent laparoscopic sleeve gastrectomy in the period of 10 years. The mean age was 44.46 years. The average operating time was 111 minutes. The mean BMI of the patients before surgery was 42.24 and the weight was 123.4 kg. The mean BMI one year after the surgery corresponded to a decrease of approximately 10 and the mean weight of 93.8 kg. Rather severe acute postoperative complications occurred in 2.87% patients. An improvement or complete cure of type two diabetes mellitus was observed in 57.8% patients. CONCLUSION: Currently, laparoscopic sleeve gastrectomy is the most common bariatric operation at the Military University Hospital in Prague. This study demonstrates a satisfactory effect of bariatric surgery in terms of long-term significant weight loss and an improvement or even cure of associated diseases such as type two diabetes mellitus, arterial hypertension and others.
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Laparoscopia , Militares , Obesidade Mórbida , Adulto , Índice de Massa Corporal , Feminino , Gastrectomia , Hospitais Universitários , Humanos , Masculino , Obesidade Mórbida/cirurgia , Estudos Retrospectivos , Resultado do TratamentoRESUMO
We discuss a technique to strongly couple a single target quantum emitter to a cavity mode, which is enabled by virtual excitations of a nearby mesoscopic ensemble of emitters. A collective coupling of the latter to both the cavity and the target emitter induces strong photon nonlinearities in addition to polariton formation, in contrast to common schemes for ensemble strong coupling. We demonstrate that strong coupling at the level of a single emitter can be engineered via coherent and dissipative dipolar interactions with the ensemble, and provide realistic parameters for a possible implementation with SiV^{-} defects in diamond. Our scheme can find applications, amongst others, in quantum information processing or in the field of cavity-assisted quantum chemistry.
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OBJECTIVE: To validate and evaluate the performance metrics of the high-throughput semiconductor sequencing platform, Ion Proton®, in non-invasive prenatal genetic screening (NIPS) for common fetal aneuploidies in a clinical setting. METHODS: This prospective cohort study included 2505 pregnant women from eight academic genetics laboratories (695 high risk for trisomy 21 (risk ≥ 1/250) pregnancies in a validation study, and 1810 such pregnancies, without ultrasound anomalies, in a real-life NIPS clinical setting). Outcome was available for all cases in the validation cohort and for 521 in the clinical cohort. Cell-free DNA from plasma samples was sequenced using the Ion Proton sequencer, and sequencing data were analyzed using the open-access software, WISECONDOR. Performance metrics for detection of trisomies 21, 18 and 13 were calculated based on either fetal karyotype result or clinical data collected at birth. We also evaluated the failure rate and compared three methods of fetal fraction quantification (RASSF1A assay, and DEFRAG and SANEFALCON software). RESULTS: Results from both cohorts were consistent and their gestational age was not significantly different so their data were combined to increase the sample size for analysis. Sensitivities and specificities, respectively, were as follows: for trisomy 21, 98.3% (95% CI, 93.5-99.7%) and 99.9% (95% CI, 99.4-100%); for trisomy 18, 96.7% (95% CI, 80.9-99.8%) and 100% (95% CI, 99.6-100%); and for trisomy 13, 94.1% (95% CI, 69.2-99.7%) and 100% (95% CI, 99.6-100%). Our failure rate was 1.2% initially and as low as 0.6% after retesting some of the failed samples. Fetal fraction estimation by the RASSF1A assay was consistent with DEFRAG results, and both were adequate for routine diagnosis. CONCLUSIONS: We describe one of the largest studies evaluating Ion Proton-based NIPS and the first clinical study reporting pregnancy outcome in a large series of patients. This platform is highly efficient in detecting the three most common trisomies. Our protocol is robust and can be implemented easily in any medical genetics laboratory. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.
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Ácidos Nucleicos Livres/sangue , Doenças Fetais/genética , Testes Genéticos/métodos , Sequenciamento de Nucleotídeos em Larga Escala/estatística & dados numéricos , Diagnóstico Pré-Natal/métodos , Aneuploidia , Ácidos Nucleicos Livres/genética , Síndrome de Down/genética , Feminino , Doenças Fetais/sangue , Idade Gestacional , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Cariótipo , Valor Preditivo dos Testes , Gravidez , Resultado da Gravidez , Estudos Prospectivos , Semicondutores , Síndrome da Trissomia do Cromossomo 13/genética , Síndrome da Trissomía do Cromossomo 18/genéticaRESUMO
We investigate laser cooling of an ensemble of atoms in an optical cavity. We demonstrate that when atomic dipoles are synchronized in the regime of steady-state superradiance, the motion of the atoms may be subject to a giant frictional force leading to potentially very low temperatures. The ultimate temperature limits are determined by a modified atomic linewidth, which can be orders of magnitude smaller than the cavity linewidth. The cooling rate is enhanced by the superradiant emission into the cavity mode allowing reasonable cooling rates even for dipolar transitions with ultranarrow linewidth.
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INTRODUCTION: Obstructive sleep apnea (OSA) is common but under-recognized after stroke. The aim of this study was to determine whether post-stroke phenotypic OSA subtypes are associated with stroke outcome in a population-based observational cohort. METHODS: Ischemic stroke patients (n = 804) diagnosed with OSA (respiratory event index ≥10) soon after ischemic stroke were identified from the Brain Attack Surveillance in Corpus Christi (BASIC) project. Functional, cognitive, and quality of life outcomes were assessed at 90 days post-stroke and long-term stroke recurrence was ascertained. Latent profile analysis was performed based on demographic and clinical features, pre-stroke sleep characteristics, OSA severity, and vascular risk factors. Regression models were used to assess the association between phenotypic clusters and outcomes. RESULTS: Four distinct phenotypic clusters provided the best fit. Cluster 1 was characterized by more severe stroke; cluster 2 by severe OSA and higher prevalence of medical comorbidities; cluster 3 by mild stroke and mild OSA; and cluster 4 by moderate OSA and mild stroke. Compared to cluster 3 and after adjustment for baseline stroke severity, cluster 1 and cluster 2 had worse 90-day functional outcome and cluster 1 also had worse quality of life. No difference in cognitive outcome or stroke recurrence rate was noted by cluster. CONCLUSION: Post-stroke OSA is a heterogeneous disorder with different clinical phenotypes associated with stroke outcomes, including both daily function and quality of life. The unique presentations of OSA after stroke may have important implications for stroke prognosis and personalized treatment strategies.
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AVC Isquêmico , Apneia Obstrutiva do Sono , Acidente Vascular Cerebral , Humanos , AVC Isquêmico/complicações , Qualidade de Vida , Acidente Vascular Cerebral/epidemiologia , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/epidemiologia , Apneia Obstrutiva do Sono/diagnóstico , Fenótipo , Análise por ConglomeradosRESUMO
BACKGROUND: The global burden of heart failure is estimated to be around 64 million people, with many needing care and support for daily living activities. These needs are usually filled by close relatives, often a spouse, and therefore someone of a similar age to the person for whom they care. OBJECTIVES: The aim of this study was to explore the needs and experiences of caregivers caring for a person with heart failure through a qualitative interview approach. METHODS: A qualitative study was conducted in a large region in South England. 17 caregivers were interviewed using a semi-structured approach and the data analysed using thematic analysis. RESULTS: Four themes were identified from the data: a) Taking on the role of caregiver with the sub-themes of: acceptance and life changes; b) Getting to grips with being a caregiver with sub-themes: carrying out the care and coping with the care; c) Impact on own health and wellbeing: sub-themes of physical health and mental and emotional health and finally: d) Need for information and Support with sub-themes: trying to get knowledge and making sense. CONCLUSIONS: This study has shown that heart failure caregiving can have a negative impact on caregivers' own health and wellbeing and involves complex care delivery for which they receive little support. Caregivers of people with heart failure report having significant information needs in order to understand the reasons for the care they provide yet feel marginalised by health care professionals.
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Cuidadores , Insuficiência Cardíaca , Adaptação Psicológica , Cuidadores/psicologia , Insuficiência Cardíaca/terapia , Humanos , Saúde Mental , Pesquisa QualitativaRESUMO
Previous studies have shown that plasma membrane compounds are involved in the contact-dependent inhibition of growth of human diploid fibroblasts. The purification of the active plasma membrane glycoprotein is described in this report. The glycoprotein has an apparent molecular mass of 60-70 kD and, due to differential sialylation, isoelectric points between pH 5.5. and 6.2. Treatment with sialidase yielded one spot in two-dimensional gel electrophoresis with an isoelectric point of 6.3. After removal of the N-glycosidically linked oligosaccharide chains, the apparent molecular mass is reduced by approximately 22 kD. Treatment was diluted NaOH, which removes the O-glycosidically linked portion of oligosaccharides, resulted in a reduction of the apparent molecular mass by approximately 5 kD. The addition of 50 ng/ml of this glycoprotein-for which the term "contactinhibin" is proposed-in immobilized form to sparsely seeded human fibroblasts resulted in a reversible 70-80% inhibition of growth. The inhibition was not confined to human fibroblasts as other cells were also inhibited, with the exclusion of transformed cells, which are refractory to contactinhibin. The inhibitory activity was abolished by treatment with beta-galactosidase or glycopeptidase F, indicating that the glycan moiety is the biologically active part of the molecule. Confluent cultures treated with antibodies raised against contactinhibin were released from the contact-dependent inhibition of growth. In addition to enhanced saturation density, these cultures exhibited a crisscross growth pattern and the formation of foci. Immunocytochemical studies showed that contactinhibin was associated with vimentin. Furthermore, contactinhibin was found to be not expressed in a species- or organ-specific manner.
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Comunicação Celular , Divisão Celular , Inibição de Contato , Glicoproteínas de Membrana/fisiologia , Animais , Linhagem Celular , Membrana Celular/fisiologia , Membrana Celular/ultraestrutura , Células Cultivadas , Cromatografia em Gel , Citoesqueleto/fisiologia , Citoesqueleto/ultraestrutura , Eletroforese em Gel de Poliacrilamida , Fibroblastos/citologia , Fibroblastos/fisiologia , Humanos , Glicoproteínas de Membrana/isolamento & purificação , Microscopia Eletrônica , Peso MolecularRESUMO
The development of hormone-refractory prostate cancer cells is one of the major causes for the progression and high mortality rates in advanced prostate cancer (PCA). While the loss of the androgen receptor (AR) is the predominant mechanism for development of a hormone-insensitive disease in vitro, the first in vivo studies showed that the AR is still expressed or is even overexpressed in hormone-refractory PCA. In view of the increasing cases of PCA in the industrialized Western countries, a series of cell and molecular biological studies has led to the identification of various new factors and mechanisms that play a role during the development of hormone-refractory tumors. These findings should lead to the development of new therapeutic strategies.
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Neoplasias Hormônio-Dependentes/genética , Neoplasias Hormônio-Dependentes/terapia , Neoplasias da Próstata/genética , Neoplasias da Próstata/terapia , Receptores Androgênicos/genética , Antagonistas de Androgênios/uso terapêutico , Animais , Linhagem Celular Tumoral , Análise Mutacional de DNA , Regulação da Expressão Gênica/fisiologia , Humanos , Masculino , Polimorfismo Genético/genética , Prognóstico , Ratos , Receptores Androgênicos/efeitos dos fármacos , Transdução de Sinais/genéticaRESUMO
The effect of testosterone on compensatory renal hypertrophy (CRH) remains controversial. We therefore examined the effect of exogenous testosterone on CRH in adult male and female rats after unilateral nephrectomy. The influence of endogenous testosterone was studied by comparing the degree of CRH in normal male, castrated male, and in testosterone receptor deficient male pseudohermaphrodite rats. Furthermore, serial determinations of serum testosterone levels were performed after unilateral nephrectomy in male rats. Compensatory renal hypertrophy was comparable between male rats--with or without exogenous testosterone administration--and between normal male, castrated male, and psuedohermaphrodite male rats. In contrast, exogenous testosterone administration in female rats enhanced CRH. Serum testosterone levels fell markedly after unilateral nephrectomy or sham surgery, but increased to 183% and 234% of control values at 1 and 2 days after surgery in the unilaterally nephrectomized rats. At no time, however, did they exceed the range of normal values. The results indicate a different effect of testosterone on CRH in male and female rats.
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Rim/patologia , Testosterona/farmacologia , Animais , Peso Corporal/efeitos dos fármacos , Transtornos do Desenvolvimento Sexual/patologia , Feminino , Hipertrofia/patologia , Rim/efeitos dos fármacos , Masculino , Nefrectomia , RatosRESUMO
Serum androgens testosterone (T), testosterone-like-substances (TLS), delta4-androstenedione (delta4), dihydrotestosterone (DHT), dehydroepiandrosterone (DHEA) were measured in 85 normal girls and 101 normal boys grouped according to pubic hair development in Tanner stages I to IV/V. The pattern of change with puberty differed for each androgen. In boys T and TLS rose with the onset of puberty but showed a more abrupt rise later in puberty. DHT also was higher in boys in late puberty but did not demonstrate a steep rise. The other androgens did not show a sex difference at any stage of puberty. While delta4 steroids did not show an increase in the years before onset of puberty, DHEA was significantly higher in prepubertal children over 7 years than in those under 7 years (mean +/- SD 166 +/- 110 vs. 31 +/- 25, P less than 0.005). The most rapid increase of DHEA concentrations was observed with the appearance of pubic hair (Stage II) in boys and girls. This contrasted with the more gradual rise of delta4 in both sexes. The oldest boys and girls (Tanner stages IV/V) had mean concentrations of all androgens in the adult range except for DHT. Twenty-two girls with precocious adrenarche (PA) aged 3-8 years had mean concentrations of T, DHT, delta4 and DHEA that were significantly higher (P less than 0.05) than in prepubertal children, but similar to those of girls in stage II and significantly lower (P less than 0.02) than in late pubertal girls (stage IV/V). Longitudinal studies in 12 of the girls indicated fluctuation of androgen concentrations, especially DHEA, but in general no increase during the years of followup. Precocious adrenarche appears to be a non-progressive disorder associated with an advanced maturation of adrenal androgen to an early pubertal stage. A rise in all androgens measured was correlated with the development of sexual hair.
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Córtex Suprarrenal/crescimento & desenvolvimento , Glândulas Suprarrenais/crescimento & desenvolvimento , Androgênios/sangue , Puberdade , Doenças do Córtex Suprarrenal/sangue , Fatores Etários , Androstenodiona/sangue , Criança , Pré-Escolar , Desidroepiandrosterona/sangue , Di-Hidrotestosterona/sangue , Feminino , Humanos , Masculino , Fatores Sexuais , Testosterona/sangueRESUMO
Dehydroepiandrosterone sulfate (DS) concentration was measured in the sera of premature and full-term infants and in children throughout puberty. Panhypopituitary, Addisonian, and virilized children were also studied. DS decreased slowly during the first weeks of life from a high level in neonates to the low levels observed between one to five years. After five years of age, DS concentration started to rise. A steeper increase was observed with the onset of puberty, and adult DS concentrations were reached in late puberty. There was no sex difference in DS concentration at any pubertal stage or bone age. Day-to-day variations were small in childhood and during puberty, but were considerable in premature infants. DS concentrations measured at 0900 h were not significantly different from those at 1700 h. There was a positive correlation of serum DS concentrations with the excretion of urinary 17-ketosteroids in boys and girls (r=0.789). Premature infants had DS concentration in or above the late pubertal range. Five panhypopituitary patients and five Addisonian patients had DS concentrations below normal. DS was markedly elevated in patients with congenital adrenal hyperplasia and in one girl with adrenal carcinoma, and was suppressible with dexamethasone in the former. The ease of measurement and the small amount of blood required make serum DS determination a useful guide for adrenal androgen secretion.
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Glândulas Suprarrenais/fisiologia , Androgênios/metabolismo , Desidroepiandrosterona , 17-Cetosteroides/urina , Adolescente , Neoplasias das Glândulas Suprarrenais/diagnóstico , Hiperfunção Adrenocortical/diagnóstico , Hormônio Adrenocorticotrópico , Adulto , Determinação da Idade pelo Esqueleto , Estatura , Criança , Pré-Escolar , Desidroepiandrosterona/sangue , Dexametasona , Feminino , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Masculino , Gravidez , Puberdade , Fatores SexuaisRESUMO
Extensive hormonal evaluation was performed in a girl with adrenal carcinoma during the primary tumor stage, following adrenalectomy, during the period when metastases were evident and while on treatment with o,p'-DDD. At the age of 14 months a diagnosis of congenital adrenal hyperplasia was made and treatment with dexamethasone (0.125 to 0.25 mg/day) resulted in a fall-off in growth rate, normal advancement in bone age, decrease in virilization and suppression of 17- ketosteroid excretion which continued until 4 3/12 years of age when virilization increased. At five years of age elevated serum and urinary androgen levels unsuppressible with dexamethasone were noted. Following removal of a large right adrenal carcinoma, serum and urinary hormone levels returned to normal. There months following surgery, liver metastases were documented associated with elevated levels of serum androgens. With o,p'-DDD treatment, serum dehydroepiandrosterone sulfate (DS) and urinary 17-ketosteroid (17-KS) excretion fell rapidly while there was a delay in the fall of free androgens. The persistence of free steroid secretion with decreased formation of DS suggests that the o,p'-DDD may have altered sulfatase activity before causing tumor necrosis and total decrease in steroidogenesis.
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Neoplasias das Glândulas Suprarrenais/complicações , Androgênios/metabolismo , Dexametasona/farmacologia , Mitotano/efeitos adversos , Virilismo/etiologia , 17-Cetosteroides/urina , Neoplasias das Glândulas Suprarrenais/diagnóstico , Neoplasias das Glândulas Suprarrenais/tratamento farmacológico , Hiperfunção Adrenocortical/diagnóstico , Hiperfunção Adrenocortical/tratamento farmacológico , Pré-Escolar , Desidroepiandrosterona/sangue , Depressão Química , Dexametasona/uso terapêutico , Diagnóstico Diferencial , Feminino , Humanos , Lactente , Mitotano/uso terapêutico , Metástase NeoplásicaRESUMO
Endocrinologic and serologic studies of a 2-year-old child with the chromosomal complement 46,XX and ambiguous genitalia suggested the preoperative diagnosis of true hermaphroditism. Urinary and serum androgen production in response to human chorionic gonadotrophin was in the range expected for normal males, implying presence of cryptic testicular tissue. Moreover, detection of H-Y antigen, a cell surface component associated with testicular differentiation and coded or regulated by a Y-chromosomal gene, indicated presence of Y-chromosomal material. The diagnosis of true hermaphroditism was confirmed at surgery. Assuming a constant association of H-Y antigen and testicular differentiation is established, human H-Y serology may be an important adjunct to the endocrinologic evaluation of intersex patients. Our studies support the interpretation that a Y-chromosomal translocation too small for cytologic detection accounts for testicular differentiation in 46,XX true hermaphroditism. Expression of H-Y antigen remained positive after castration.
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Transtornos do Desenvolvimento Sexual/genética , Isoantígenos/análise , Cromossomos Sexuais/imunologia , Hormônio Adrenocorticotrópico/farmacologia , Pré-Escolar , Gonadotropina Coriônica/farmacologia , Aberrações Cromossômicas , Transtornos Cromossômicos , Dexametasona/farmacologia , Transtornos do Desenvolvimento Sexual/patologia , Feminino , Genótipo , Hormônios/sangue , Humanos , Testosterona/sangueRESUMO
The diagnosis of 5 alpha-reductase deficiency was proven in two prepubertal patients with male pseudohermaphroditism (MPH). Both had a 46-XY karyotype and were reared as females; one child had been castrated in infancy. Clitoromegaly, urogenital sinus, and short vaginal pouch were present in both; inguinal gonads were palpable in one. The diagnosis was made biochemically by observing characteristic changes in five parameters: 1) abnormally high testosterone to dihydrotestosterone (T:DHT) ratio after hCG stimulation (35 and 53 vs. normal, 11 +/- 3), 2) abnormally high 5 beta-T metabolites in urine (8.1 and 6.0 vs. normal, less than 1),3) deficient conversion of T to DHT during [3H] T infusion (0.3 and 0.4% vs. normal, 5.3 +/- 3), 4) deficient conversion of [14 C] T to 5 alpha-reduced metabolites by nongenital skin fibroblasts (2.2 and 1.9 pmol/microgram DNA/nmol substrate vs. 68.4+/- 7.8 Pmol/microgram DNA/nmol substrate in normal controls), and 5) deficient conversion of [14C]T to DHT in genital skin slices. The fact that this syndrome represents a defect in T metabolism rather in in T binding is demonstrated by the observation that binding of [3H]DHT to cytosol of skin fibroblasts was normal (4.2 dpm/micrograms DNA vs. normal male values of 3.7 +/- 0.64). Thus, the present report suggests that 5 alpha-reductase deficiency can be diagnosed during childhood and even after castration by metabolic studies of nongenital skin fibroblasts and determination of the conversion ratio of [3H]T to [3H]DHT in plasma.
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3-Oxo-5-alfa-Esteroide 4-Desidrogenase/deficiência , Transtornos do Desenvolvimento Sexual/enzimologia , Oxirredutases/deficiência , Puberdade , Androgênios/urina , Castração , Células Cultivadas , Criança , Gonadotropina Coriônica , DNA/metabolismo , Di-Hidrotestosterona/metabolismo , Feminino , Fibroblastos/metabolismo , Humanos , Cariotipagem , Masculino , Pele/metabolismo , Testosterona/metabolismoRESUMO
14C-hexachlorobutadiene (HCBD), a mutagenic and nephrocarcinogenic pollutant, was administered by oral gavage of 100 mg/kg to female rats, and the radioactivity in 24 hr urine pooled. The average amount of radioactivity recovered in urine was 5.4% of the total 14C-activity ingested. Solvent extraction, high performance liquid chromatography (HPLC), radio gas chromatography and gas chromatography/mass spectrometry were used for separation and identification of metabolites. After solvent extraction and HPLC four fractions were separated containing 1%, 5%, 15% and 80% of radioactivity. In the 80% fraction one metabolite was identified after derivatization and comparison with the authentic compound as the mercapturic acid of HCBD (N-acetyl-S-1,1,2,3,4-pentachlorobutadienyl)-L-cysteine). The mercapturic acid accounts for 10% of the urinary 14C-activity. In a first attempt the mutagenic potential of the mercapturic acid was determined on Salmonella typhimurium TA 100 with and without metabolic activating S9 mix. In the presence of S9 mix the mercapturic acid exerts a strong mutagenic effect which proved to be about 80 times higher than that of HCBD. The results identify the formation of the mercapturic acid via direct glutathione conjugation as an activating and intermediary step in the metabolism of hexachlorobutadiene.
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Acetilcisteína/metabolismo , Butadienos/metabolismo , Animais , Biotransformação , Butadienos/intoxicação , Radioisótopos de Carbono , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Mutagênicos/metabolismo , Ratos , Ratos Endogâmicos , Salmonella typhimurium/efeitos dos fármacosRESUMO
Excretion, covalent binding and metabolism of hexachloro-1,3-butadiene (HCBD), a nephrotoxic and nephrocarcinogenic compound, have been studied in female rats. Seventy-two hours after administration of a single oral dose of 1 mg/kg [14C]HCBD, 5.3% of the dose were exhaled as unchanged HCBD and 76.3% were metabolized and excreted in urine and feces or exhaled as 14CO2. After a 50 mg/kg dose of [14C]HCBD, the amount of exhaled parent compound was nearly unchanged at 5.4%. At the higher dose the gastro-intestinal absorption of HCBD appeared to be saturated with the result that unchanged HCBD constituted the major portion of the 69% radioactivity eliminated. Covalent binding to proteins in kidney and liver agreed well with the organ-specific toxicity of HCBD: binding was higher in the kidney, independent of the dose. It increased significantly when the rats were pretreated with phenobarbital, an inducer of monooxygenases; it decreased when the inhibitor piperonyl butoxide was given. Urinary radioactivity in 24 hr urine was separated by column chromatography into four fractions. High performance liquid chromatography, radio gas chromatography and gas chromatography/mass spectrometry were used for further separation and identification. Two major metabolites were identified as pentachlorobutadiene methylthio ether and pentachlorobutadiene carboxymethylthio ether. Their formation is plausibly explained via glutathione conjugation, which appears to be the first step in HCBD metabolism. The mechanism of the conjugation at the olefinic double bond of HCBD is explained by an addition-elimination reaction. This pathway, which appears to lead to a destabilization of the HCBD molecule, could explain the distinct nephrotoxic effects of HCBD.
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Butadienos/metabolismo , Animais , Sítios de Ligação , Biotransformação , Butadienos/urina , Cromatografia/métodos , Feminino , Espectrometria de Massas , Taxa de Depuração Metabólica , Ligação Proteica , Ratos , Ratos Endogâmicos , Distribuição TecidualRESUMO
Growth of normal diploid mammalian cells in vitro is strongly regulated by the actual cell density. Cell-cell contacts via specific plasma membrane glycoproteins whose glycan moieties interact with specific receptors has been found to be a main growth regulatory principle. Malignant growth is suggested to result from impaired function of these receptors.
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Comunicação Celular/fisiologia , Divisão Celular/fisiologia , Glicoproteínas da Membrana de Plaquetas/fisiologia , Adesão Celular/fisiologia , Agregação Celular/fisiologia , Inibição de Contato/fisiologia , Humanos , Glicoproteínas da Membrana de Plaquetas/químicaRESUMO
A case of a desmoid tumor originally appeared as an orbital mass lesion in a 63-year-old woman. This is a most unusual location for this tumor and, to our knowledge, only one previous case of this type has been reported in the ophthalmic literature.
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Fibroma/patologia , Neoplasias Orbitárias/patologia , Feminino , Humanos , Pessoa de Meia-IdadeRESUMO
Insect-based BioFETs (biologically sensitive field-effect transistors) with improved signal characteristics have been developed. These BioFETs require a specifically adapted signal interfacing between a FET as signal transducer and an intact insect antenna as biocomponent. Therefore, different field-effect transistors have been fabricated in order to study the signal transfer at the bioelectronic interface. As relevant features of the BioFET, its current-voltage characteristics, the transconductance and the signal-to-noise ratio have been investigated as affected by the choice of gate insulator materials and gate dimensions (width-to-length ratio, thickness of the dielectric layers). The performance of the improved FET arrangement in the isolated-antenna BioFET was validated by employing dilution series of the plant odour component Z-3-hexen-1-ol.