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3.
Eye (Lond) ; 27(4): 525-30, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23328804

RESUMO

BACKGROUND: Current methods of treating the avascular retina with laser photocoagulation for severe retinopathy of prematurity (ROP) are not completely effective in the reduction of visual morbidity. We report a case series in which additional laser treatment, called 'posterior laser', was delivered posterior to the neovascular ridge, for eyes with severe stage 3 ROP in zone II with avascular retina posterior to the ridge. DESIGN: Retrospective chart review. PARTICIPANTS: Infants who underwent laser treatment, posterior to the neovascular ridge for severe ROP at the Alberta Children's Hospital, between January 2005 and October 2008. METHODS: Charts were reviewed for 18 eyes of 11 patients and collected information included demographic data, clinical examination results, and digital retinal images. MAIN OUTCOME MEASURES: Structural and functional outcomes of treatment. RESULTS: Four (22%) of 18 eyes received 'posterior laser' as primary treatment and the remainder of eyes (78%) received 'posterior laser' following previous laser photocoagulation anterior to the neovascular ridge. Mean birthweight was 688 g (552-930) and mean gestational age was 24 weeks (23-28). There were no complications because of the posterior laser treatment. In all, 16 of 18 eyes experienced rapid regression of the ridge and subsequent decrease in vascular dilation and tortuosity within 1 week. Two eyes required vitrectomy for 4A retinal detachment; however, no eyes developed stage 4B ROP. CONCLUSION: Posterior to the ridge laser in the setting of the morphological criteria described had no increased safety concerns and resulted in rapid regression of ROP with good outcomes.


Assuntos
Terapia a Laser/métodos , Retinopatia da Prematuridade/cirurgia , Canadá , Feminino , Humanos , Recém-Nascido , Masculino , Neovascularização Retiniana/patologia , Neovascularização Retiniana/cirurgia , Retinopatia da Prematuridade/patologia , Estudos Retrospectivos
4.
J Trace Elem Med Biol ; 26(2-3): 97-101, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22677543

RESUMO

ATP7B mutations result in Cu storage in the liver and brain in Wilson disease (WD). Atox1 and COMMD1 were found to interact with ATP7B and involved in copper transport in the hepatocyte. To understand the molecular etiology of WD, we analyzed ATP7B, Atox1 and COMMD1 genes. Direct sequencing of (i) ATP7B gene was performed in 112 WD patients to identify the spectrum of disease-causing mutations in the French population, (ii) Atox1 gene was performed to study the known polymorphism 5'UTR-99T>C in 78 WD patients with two ATP7B mutations and (iii) COMMD1 gene was performed to detect the nucleotide change c.492GAT>GAC. MLPA (Multiplex Ligation-dependent Probe Amplification) analysis was performed in WD patients presenting only one ATP7B mutation. Among our 112 WD unrelated patients, 83 different ATP7B gene mutations were identified, 27 of which were novel. Two ATP7B mutations were identified in 98 WD cases, and one mutation was identified in 14 cases. In two of these 14 WD patients, we identified the deletion of exon 4 of the ATP7B gene by MLPA technique. In 78 selected patients of the cohort with two mutations in ATP7B, we have examined genotype-phenotype correlation between the detected changes in Atox1 and COMMD1 genes, and the presentation of the WD patients. Based on the data of this study, no major role can be attributed to Atox1 and COMMD in the pathophysiology or clinical variation of WD.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Adenosina Trifosfatases/genética , Proteínas de Transporte de Cátions/genética , Degeneração Hepatolenticular/genética , Chaperonas Moleculares/genética , Adolescente , Adulto , Proteínas de Transporte de Cobre , ATPases Transportadoras de Cobre , Feminino , Estudos de Associação Genética , Humanos , Masculino , Metalochaperonas , Modelos Biológicos , Adulto Jovem
5.
Arch Dis Child ; 97(9): 822-4, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22550320

RESUMO

OBJECTIVE: To evaluate whether dual energy x-ray absorptiometry (DXA) and quantitative ultrasound (QUS) classify the same children as 'abnormal' (SD (z) score (SDS) ≤-2). METHODS: Speed of sound (SOS) was measured at the radius and tibia using QUS and lumbar spine bone mineral density (BMD) using DXA in 621 subjects aged 5-20 years; healthy 412, cystic fibrosis 117 and obese 92. RESULTS: BMD SDS positively (p<0.001) and tibia SOS SDS negatively correlated with size (p<0.05). Disagreement between DXA and QUS for 'abnormal' scans occurred in 6-31%. Those with abnormal BMD and normal SOS SDS had lower mean BMI SDS than those with normal BMD and abnormal SOS SDS. SOS measurements were unobtainable in some children, especially in the obese group. CONCLUSIONS: DXA and QUS identify different individuals as 'abnormal'. Agreement between BMD and tibia SOS is lower in obese subjects. Without a gold-standard, it is difficult to determine which technique is more 'correct'.


Assuntos
Absorciometria de Fóton , Densidade Óssea/fisiologia , Doenças Ósseas/diagnóstico por imagem , Adolescente , Doenças Ósseas/fisiopatologia , Criança , Pré-Escolar , Fibrose Cística/fisiopatologia , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/fisiologia , Obesidade/fisiopatologia , Rádio (Anatomia)/diagnóstico por imagem , Rádio (Anatomia)/fisiologia , Tíbia/diagnóstico por imagem , Tíbia/fisiologia , Ultrassom , Ultrassonografia , Adulto Jovem
6.
Transplant Proc ; 42(6): 2112-4, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20692421

RESUMO

BACKGROUND: The islets of Langerhans are micro-organs rich in blood vessels. The process of islet isolation and culture disrupts the vasculature of the islets. The reestablishment of an appropriate microvascular supply is an essential prerequisite for long-term survival and function of islet grafts. In this study, we examined the effects on the process of neovascularization of coating the islets with fibrin. METHODS: Isolated human islets were stained using the dioctadecylindocarbocyanine (DII) dye. An aliquot of the human islets were embedded in 3-dimensional fibrin. Human islets (100 islets-equivalents) were transplanted into a mouse dorsal window model to evaluate angiogenesis over 17 days. Transplanted islets were divided into 2 groups: either free islets or islets coated with fibrin gel. Animals were imaged using intravital microscopy immediately and at 3, 4, 8, 11, and 17 days after surgery. The DII dye caused the islets to be fluorescent and visible using a rhodamine filter. Fluorescein isothiocyanate dextran was used to visualize vasculature structures surrounding the islets. RESULTS: Human islets coated with fibrin demonstrated an early appearance of a network of immature blood vessels that produced a significantly higher density/unit area for neovascularization by day 8 after transplantation. CONCLUSION: Our preliminary data showed that fibrin played a role in early neovascularization and support to sustain development of new blood vessels. Fibrin formed a matrix that helped to maintain the 3-dimensional structure of, and therefore reducing the environmental stress on islets.


Assuntos
Fibrina/fisiologia , Transplante das Ilhotas Pancreáticas/fisiologia , Ilhotas Pancreáticas/irrigação sanguínea , Neovascularização Fisiológica/fisiologia , Animais , Humanos , Ilhotas Pancreáticas/citologia , Transplante das Ilhotas Pancreáticas/métodos , Camundongos , Transplante Heterólogo/métodos
7.
Clin Exp Immunol ; 144(1): 117-24, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16542373

RESUMO

Interleukin (IL)-18, a proinflammatory cytokine, has been recognized recently as an important factor in both treated and untreated patients with human immunodeficiency virus type 1 (HIV-1) infection. Consistent with all earlier reports, our quantification of serum IL-18 concentrations in 88 HIV-1 seropositive, North American adolescents (14-18 years old) revealed a positive correlation with cell-free HIV-1 viral load at two separate visits (Spearman's r = 0.31 and 0.50, respectively, P < 0.01 for both), along with a negative correlation with CD4+ T cell counts (r = -0.31 and -0.35, P < 0.01 for both). In additional analyses of 66 adults (21-58 years old) from Zambia, HIV-1 seroconversion was associated uniformly with elevated IL-18 production (P < 0.0001). These epidemiological relationships were independent of other population-related characteristics, including age, gender and ethnicity. In neither study population could serum IL-18 concentrations be associated with the IL-18 gene (IL18) promoter genotypes defined by five major single nucleotide polymorphisms. Collectively, these findings suggest that circulating IL-18 rather than the IL18 genotype may provide a useful biomarker for HIV-1-related events or outcomes.


Assuntos
Infecções por HIV/imunologia , HIV-1/imunologia , Interleucina-18/imunologia , ADP-Ribosil Ciclase 1/imunologia , Adolescente , Adulto , Biomarcadores/análise , Contagem de Linfócito CD4 , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Feminino , Genótipo , Infecções por HIV/etnologia , Infecções por HIV/genética , Haplótipos , Humanos , Interleucina-18/análise , Interleucina-18/genética , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genética , Polimorfismo de Nucleotídeo Único/imunologia , Regiões Promotoras Genéticas/genética , Regiões Promotoras Genéticas/imunologia , Carga Viral
8.
Int J Gynecol Cancer ; 14(1): 1-11, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-14764024

RESUMO

Although age-adjusted cancer death rates have started to decline in the United States and other developed nations - thanks in large part to widespread screening programs that detect cancers at early, treatable stages - cancer in developing countries is on the rise. Ironically, rising life expectancy in those nations along with the adoption of 'Western' lifestyles will leave many more people vulnerable to cancer. Unfortunately, the early detection tools and treatment technology that have helped control cancer in wealthier lands are often not readily available in many other countries. Much of this increased cancer burden will take the form of cancers that affect women - not only breast, cervical, and other gynecologic cancers but colorectal cancer, lung cancer, and other malignancies related to tobacco. Physicians specializing in cancer care for women need to be alert to every opportunity to improve cancer screening and prevention among the growing, aging populations of less-developed countries. Less precise but less costly and more widely available screening techniques may save thousands more lives than the most sophisticated technology because low-cost programs can be applied widely instead of being reserved for a fortunate few. In addition, education and prevention efforts directed toward tobacco use need to be put in place to help stem an epidemic of tobacco-related cancers that has largely peaked in developed countries but looms ominously in the future of developing nations.


Assuntos
Efeitos Psicossociais da Doença , Neoplasias/epidemiologia , Neoplasias/prevenção & controle , Saúde da Mulher , Neoplasias da Mama/epidemiologia , Neoplasias Colorretais/epidemiologia , Países Desenvolvidos , Países em Desenvolvimento , Feminino , Neoplasias dos Genitais Femininos/epidemiologia , Humanos , Neoplasias Pulmonares/epidemiologia , Neoplasias/etiologia , Fumar
9.
Anaesthesia ; 59(1): 27-33, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14687095

RESUMO

Tracheal intubating conditions were assessed in 112 children after induction of anaesthesia with propofol and remifentanil 1.0, 2.0 or 3.0 micro g.kg-1. Subjects in a control group were given propofol and mivacurium 0.2 mg.kg-1. Haemodynamic and respiratory parameters were recorded. Plasma catecholamine levels were measured in a subgroup of 40 children. Intubating conditions were acceptable in 14/28 (50%), 18/26 (69%) and 22/27 (82%) in those subjects given remifentanil 1.0, 2.0 or 3.0 micro g.kg-1, respectively, and in 27/28 (96%) of the control group. Intubating conditions in subjects given remifentanil 3.0 micro g.kg-1 were better than in those given remifentanil 1.0 micro g.kg-1 (p < 0.05). There were no significant differences in intubating conditions between those given remifentanil 3.0 micro g.kg-1 and the control group. Systolic blood pressure and heart rate increased in response to tracheal intubation in subjects given remifentanil 1.0 micro g.kg-1 and in the control group (p < 0.05). Time to resumption of spontaneous respiration was prolonged in subjects given remifentanil 3.0 micro g.kg-1 (p < 0.001). In conclusion, remifentanil 2 micro g.kg-1 provides acceptable intubating conditions and haemodynamic stability without prolonging the return of spontaneous respiration.


Assuntos
Analgésicos Opioides/administração & dosagem , Anestésicos Intravenosos , Intubação Intratraqueal/métodos , Piperidinas/administração & dosagem , Propofol , Pressão Sanguínea/efeitos dos fármacos , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Epinefrina/sangue , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Laringoscopia , Masculino , Norepinefrina/sangue , Remifentanil , Respiração/efeitos dos fármacos
10.
Gynecol Endocrinol ; 16(1): 19-25, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11915577

RESUMO

Uterine flushings were obtained under transvaginal ultrasonographic control from 132 women presenting for investigation and treatment of infertility. Levels of CA 125 were measured by radioimmunoassay and results expressed in relation to the total protein concentration of the same flushings. CA 125 was detected in uterine fluid at levels higher than those previously reported in peripheral blood. Uterine fluid CA 125 concentrations varied throughout the menstrual cycle, being highest in the mid-follicular phase (days 6 to 10). Uterine fluid CA 125 concentrations may reflect endometrial secretion of this protein more directly than serum levels. CA 125 concentrations did not vary according to the cause of infertility but further work in larger numbers of women is required.


Assuntos
Líquidos Corporais/química , Antígeno Ca-125/análise , Infertilidade Feminina/etiologia , Ciclo Menstrual , Útero/metabolismo , Adulto , Antígeno Ca-125/metabolismo , Endométrio/metabolismo , Endométrio/patologia , Feminino , Fase Folicular , Humanos , Infertilidade Feminina/patologia
11.
J Adolesc Health ; 29(3 Suppl): 109-14, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11530311

RESUMO

PURPOSE: To describe baseline prevalence of oral mucosal diseases among HIV infected adolescents in relationship to biological and behavioral risk factors. METHODS: Participants in Reaching for Excellence in Adolescent Care and Health (REACH), a multicenter longitudinal observational study of HIV/AIDS in adolescents, received physical examinations, blood tests, and oral examinations at 3-month intervals. We evaluated participants for oral conditions commonly seen in relationship to HIV, and explored the association of the most common lesion with selected biological and behavioral variables at baseline using contingency tables and Fisher's Exact test. RESULTS: Among 294 HIV infected adolescents recruited between March 1996 and March 1999, the majority were female (75%), aged 17 to 18 years (69%), and African-American (73%). More than 90% had a CD4(+) T-lymphocyte count > 200 cells/mm(3) at baseline and 57% had a plasma HIV-1 RNA concentration

Assuntos
Candidíase Bucal/etiologia , Infecções por HIV/complicações , Leucoplasia Pilosa/etiologia , Adolescente , Candidíase Bucal/virologia , Estudos de Coortes , Feminino , Humanos , Leucoplasia Pilosa/virologia , Masculino , RNA Viral/análise , Estomatite Aftosa/etiologia , Estomatite Aftosa/virologia
12.
J Adolesc Health ; 29(3 Suppl): 123-9, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11530313

RESUMO

PURPOSE: To evaluate hepatitis B (HBV) vaccine response rates in HIV infected and high-risk HIV uninfected youth and examine associations with responsiveness in the HIV infected group. METHODS: Cohorts within the Reaching for Excellence in Adolescent Care and Health (REACH) study population were defined based on receipt of HBV vaccine both retrospectively and prospectively. Sero-responsiveness was determined by HBsAb measurements. Testing was done for HBsAg, HBsAb, and HBcAb. For HBsAb, a value of > 10 International Units per liter was considered a positive response, and the data were collected as either positive or negative from each of the reporting laboratories. Covariates of responsiveness were explored in univariate and multivariate models for each cohort. RESULTS: Sixty-one subjects had received a three-dose vaccination course at the time of entry into REACH. HIV uninfected subjects had significantly higher rates of response by serology compared with HIV infected subjects (70% vs. 41.1%; chi(2) = .05; RR = .586, 95% CI: .36-.96). By the time of an annual visit 43 subjects had received three vaccinations with at least one occurring in the study period. The rates of response were similar for the HIV infected and uninfected groups (37.1% vs. 37.5%) in this cohort. Univariate and multivariate analysis in the prospective HIV infected group (N = 35) found an association between elevated CD8(+)/CD38(+)/HLA-DR(+) T cells and lack of HBV vaccine responsiveness (6.7% vs. 60%; chi(2) = .03; RR = .12, 95% CI: .02- .55). CONCLUSIONS: The poor HBV vaccine response rate in the HIV uninfected high-risk adolescents was unexpected and suggests that HBV vaccination doses have not been optimized for older adolescents. This is the first report of decreased responsiveness in HIV infected subjects being associated with elevated CD8(+)/CD38(+)/HLA(-)DR(+) T cells and suggests that ongoing viral replication and concomitant immune system activation decreases the ability of the immune system in HIV infected subjects to respond to vaccination.


Assuntos
Antígenos CD , Infecções por HIV/complicações , Vacinas contra Hepatite B/imunologia , Hepatite B/imunologia , ADP-Ribosil Ciclase , ADP-Ribosil Ciclase 1 , Adolescente , Antígenos de Diferenciação , Linfócitos T CD8-Positivos/imunologia , Estudos de Coortes , Feminino , Infecções por HIV/imunologia , Antígenos HLA-DR , Hepatite B/prevenção & controle , Humanos , Masculino , Glicoproteínas de Membrana , NAD+ Nucleosidase , Testes Sorológicos
13.
Phys Rev Lett ; 87(6): 067004, 2001 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-11497846

RESUMO

We report on time-resolved measurements of thermodynamic fluctuations in the number of particles in a nondegenerate Fermi gas. The gas is comprised of thermal quasiparticles, confined in a superconducting Al box by large-gap Ta leads. The average number of quasiparticles is about 10(5). This number fluctuates due to quasiparticle generation and recombination. The number is measured from the tunneling current through a barrier that bisects the box. The recombination time is independently measured by single-photon excitation and agrees with the frequency dependence of the fluctuations.

14.
J Assist Reprod Genet ; 17(3): 140-6, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10911573

RESUMO

PURPOSE: Women undergoing in vitro fertilization with low ovarian reserve and poor response to controlled ovarian hyperstimulation (COH) present a management dilemma. In a retrospective observational study, we compared the pretreatment use of the gestogen medroxyprogesterone acetate (10 mg twice daily from day 15 of the cycle for a minimum of 2 weeks) with an oral contraceptive pill (one tablet daily from day 4 of the cycle for a minimum of 3 weeks). METHODS: The criteria for inclusion in the study included one or more of the following: abandoned cycles due to poor response, fewer than four oocytes retrieved following a standard COH protocol, age > 39 years, and elevated basal serum follicle-stimulating hormone (FSH). Thirty-eight women received pretreatment with gestogen, and a similar number of women received pretreatment with the pill. The flare protocol was used in all treatment cycles combined with an individualized dose of human menopausal gonadotropin (hMG) (4-8 ampoules/day of 75 units FSH/ampoule) depending on previous response, age, and early follicular serum FSH level. Both groups were similar in mean age, duration of infertility, early follicular FSH levels, and the distribution of various aetiologies. RESULTS: Twenty-nine cycles were abandoned before oocyte retrieval, 15 (39.5%) in the pill group and 14 (36.8%) in the gestogen group, because of an inadequate ovarian response. The mean (+/- SD) number of ampoules (75 IU FSH/ampoule) of hMG used per cycle was similar in the pill and gestogen groups (59.7 +/- 19.3 vs. 70.2 +/- 29.4, respectively). There also was no difference seen in the numbers of oocytes retrieved (4.4 +/- 2.3 vs. 4.2 +/- 2.5), total number of embryos (2.5 +/- 2.4 vs. 2.2 +/- 1.1), or the number of embryos transferred (1.8 +/- 1.2 vs. 2.1 +/- 1.0) in the pill and gestogen groups, respectively. One pregnancy in each group resulted following embryo transfer in 22 women in the pill group and in 24 women in the gestogen group. CONCLUSIONS: We conclude that pre-IVF treatment with oral contraceptive pill or gestogen combined with the flare protocol in women at high risk of or with a history of poor ovarian response, as defined in this study, did not appear to result in an improvement in outcome of IVF-embryo transfer.


Assuntos
Anticoncepcionais Orais/farmacologia , Fertilização in vitro/métodos , Acetato de Medroxiprogesterona/farmacologia , Congêneres da Progesterona/farmacologia , Adulto , Transferência Embrionária , Feminino , Fármacos para a Fertilidade Feminina/farmacologia , Hormônio Foliculoestimulante/farmacologia , Hormônio Liberador de Gonadotropina/análogos & derivados , Humanos , Menotropinas/farmacologia , Gravidez , Resultado da Gravidez , Estudos Retrospectivos , Injeções de Esperma Intracitoplásmicas
15.
Arch Pediatr Adolesc Med ; 154(2): 127-34, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10665598

RESUMO

CONTEXT: Data suggest that in adults, human papillomavirus (HPV) infections and their sequalae, squamous intraepithelial lesions (SILs), occur more commonly among human immunodeficiency (HIV)-infected women because of the HIV-associated CD4+ T-cell immunosuppression. Since adolescents are more likely to be early in the course of HIV and HPV infections, the study of both infections in this age group may help elucidate their initial relationship. OBJECTIVE: To examine the prevalence of and risks for cervical HPV infection and SILs by HIV status in a population of adolescent girls. PARTICIPANTS: Subjects recruited at each of the 16 different US sites participating in a national study of HIV infection in adolescents. MAIN OUTCOME MEASURES: Cervical HPV DNA findings using polymerase chain reaction detection techniques and Papanicolaou smear from baseline visits. Infection with HPV was categorized into low- (rarely associated with cancer) and high- (commonly associated with cancers) risk types. RESULTS: Of 133 HIV-infected girls, 103 (77.4%) compared with 30 (54.5%) of 55 noninfected girls were positive for HPV (relative risk [RR], 1.4; 95% confidence interval [CI], 1.1-1.8). The risk was for high-risk (RR, 1.8; 95% CI, 1.2-2.7) but not low-risk (RR, 1.2; 95% Cl, 0.4-3.9) HPV types. Among the girls with HPV infection, 21 (70.0%) of the non-HIV-infected girls had normal cytologic findings compared with only 29 (29.9%) of the HIV-infected girls (P<.001). Multivariate analysis showed that HIV status was a significant risk for HPV infection (odds ratio [OR], 3.3; 95% CI, 1.6-6.7) and SIL (OR, 4.7; 95% CI, 1.8-14.8), but CD4 cell count and viral load were not associated with infection or squamous intraepithelial lesions. Only 9 girls had a CD4+ T-cell count of less than 0.2 cell X 10(9)/L. CONCLUSIONS: High prevalence of HPV infection in both groups underscores the risky sexual behavior in this adolescent cohort. Rates of HPV infection and SILs were higher among HIV-infected girls, despite similar sexual risk behaviors and the relatively healthy state of our HIV-infected group. Infection with HIV may enhance HPV proliferation through mechanisms other than CD4 immunosuppression, particularly early in the course of HIV infection.


Assuntos
Infecções por HIV/complicações , Papillomaviridae , Infecções por Papillomavirus/epidemiologia , Infecções Tumorais por Vírus/epidemiologia , Displasia do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/epidemiologia , Adolescente , Estudos de Coortes , DNA Viral/análise , Feminino , Humanos , Papillomaviridae/genética , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/complicações , Prevalência , Fatores de Risco , Infecções Tumorais por Vírus/complicações , Neoplasias do Colo do Útero/complicações , Neoplasias do Colo do Útero/virologia , Displasia do Colo do Útero/complicações , Displasia do Colo do Útero/virologia
16.
J Biol Chem ; 274(49): 35255-61, 1999 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-10575012

RESUMO

Purine transport into the protozoan parasite Toxoplasma gondii plays an indispensable nutritional function for this pathogen. To facilitate genetic and biochemical characterization of the adenosine transporter of the parasite, T. gondii tachyzoites were transfected with an insertional mutagenesis vector, and clonal mutants were selected for resistance to the cytotoxic adenosine analog adenine arabinoside (Ara-A). Whereas some Ara-A-resistant clones exhibited disruption of the adenosine kinase (AK) locus, others displayed normal AK activity, suggesting that a second locus had been tagged by the insertional mutagenesis plasmid. These Ara-A(r) AK+ mutants displayed reduced adenosine uptake capability, implying a defect in adenosine transport. Sequences flanking the transgene integration point in one mutant were rescued from a genomic library of Ara-A(r) AK+ DNA, and Southern blot analysis revealed that all Ara-A(r) AK+ mutants were disrupted at the same locus. Probes derived from this locus, designated TgAT, were employed to isolate genomic and cDNA clones from wild-type libraries. Conceptual translation of the TgAT cDNA open reading frame predicts a 462 amino acid protein containing 11 transmembrane domains, a primary structure and membrane topology similar to members of the mammalian equilibrative nucleoside transporter family. Expression of TgAT cRNA in Xenopus laevis oocytes increased adenosine uptake capacity in a saturable manner, with an apparent K(m) value of 114 microM. Uptake was inhibited by various nucleosides, nucleoside analogs, hypoxanthine, guanine, and dipyridamole. The combination of genetic and biochemical studies demonstrates that TgAT is the sole functional adenosine transporter in T. gondii and a rational target for therapeutic intervention.


Assuntos
Adenosina/genética , Adenosina/farmacocinética , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Toxoplasma/genética , Toxoplasma/metabolismo , Adenosina Quinase/genética , Sequência de Aminoácidos , Animais , Membrana Celular/metabolismo , Clonagem Molecular , DNA Complementar/metabolismo , Dados de Sequência Molecular , Mutagênese Insercional , Hibridização de Ácido Nucleico , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Fatores de Tempo , Transcrição Gênica , Xenopus
17.
Mol Biochem Parasitol ; 103(1): 1-14, 1999 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-10514076

RESUMO

A genetic approach has been exploited to investigate adenylate salvage pathways in the protozoan parasite Toxoplasma gondii, a purine auxotroph. Using a new insertional mutagenesis vector designed to facilitate the rescue of tagged loci even when multiple plasmids integrate as a tandem array, 15 independent clonal lines resistant to the toxic nucleoside analog adenine arabinoside (AraA) were generated. Approximately two-thirds of these clones lack adenosine kinase (AK) activity. Parallel studies identified an expressed sequence tag (EST) exhibiting a small region of weak similarity to human AK, and this locus was tagged in several AK-deficient insertional mutants. Library screening yielded full-length cDNA and genomic clones. The T. gondii AK gene contains five exons spanning a approximately 3 kb locus, and the predicted coding sequence was employed to identify additional AK genes and cDNAs in the GenBank and dbEST databases. A genomic construct lacking essential coding sequence was used to create defined genetic knock-outs at the T. gondii AK locus, and AK activity was restored using a cDNA-derived minigene. Hybridization analysis of DNA from 13 AraA-resistant insertional mutants reveals three distinct classes: (i) AK-mutants tagged at the AK locus; (ii) AK- mutants not tagged at the AK locus, suggesting the possibility that another locus may be involved in regulating AK expression; and (iii) mutants with normal AK activity (potential transport mutants).


Assuntos
Adenosina Quinase/genética , Toxoplasma/enzimologia , Toxoplasma/genética , Vidarabina/farmacologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Primers do DNA/genética , DNA Complementar/genética , DNA de Protozoário/genética , Resistência a Medicamentos/genética , Genes de Protozoários , Humanos , Modelos Biológicos , Dados de Sequência Molecular , Mutagênese Insercional , Purinas/metabolismo , Homologia de Sequência de Aminoácidos , Sitios de Sequências Rotuladas , Toxoplasma/efeitos dos fármacos
18.
Anaesthesia ; 54(4): 389-92, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10455843

RESUMO

Following reports that tubal smooth muscle spasm may contribute to pelvic pain following laparoscopic sterilisation, we studied the effect of buscopan (an anticholinergic agent used to relieve smooth muscle spasm) on 45 patients undergoing general anaesthesia for day-case laparoscopic sterilisation. Patients were randomly allocated to receive either buscopan 20 mg or saline placebo after induction of anaesthesia. There were no significant differences in pain scores or postoperative analgesic requirements between the two groups. We conclude that intravenous buscopan confers no benefit in day-case laparoscopic sterilisation.


Assuntos
Brometo de Butilescopolamônio/uso terapêutico , Laparoscopia , Antagonistas Muscarínicos/uso terapêutico , Dor Pós-Operatória/prevenção & controle , Esterilização Tubária , Adulto , Procedimentos Cirúrgicos Ambulatórios , Método Duplo-Cego , Feminino , Humanos , Injeções Intravenosas
19.
Mol Cell Endocrinol ; 120(1): 51-7, 1996 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-8809738

RESUMO

Human genital skin fibroblasts contain both the full-length 110 K androgen receptor protein (AR-B, apparent M(r) approximately 110,000) and an 87 K N-terminally truncated AR isoform (AR-A, apparent M(r) approximately 87,000). These two AR species are structurally analogous to the A- and B-isoforms of the progesterone receptor (PR). We examined the distribution pattern of human AR isoforms in a variety of fetal and adult tissues by Western blot analysis. Relative levels of immunoreactive AR proteins in high salt tissue extracts were estimated by densitometry in comparison to a standard normal genital skin fibroblast preparation. High AR levels (AR-A + AR-B = 0.8-7.7) were present in male and female reproductive tissues from mid-trimester fetuses, including penis, prostate, testis, epididymis, scrotal skin, labial skin, uterus/cervix, and ovary. AR-A and AR-B (0.08-0.9) also were found in 14 non-genital fetal tissues (bladder, fat, lung, great vessel, trachea, muscle, scalp skin, kidney, thyroid, intestine, thymus, ureter, stomach and rectum). AR-A accounted for 4-26% of the AR protein detected in these tissues. Ten other fetal tissues had low levels of AR-B (0.02-0.3) and little or no detectable AR-A. AR-B also was the predominant or only immunoreactive AR species found in 17 adult human tissues. AR levels in adult reproductive tissues (prostate, endometrium, ovary, uterus, fallopian tube, testis, seminal vesicle, myometrium, and ejaculatory duct) ranged from 0.1 to 2.2. Immunoreactive AR (0.4-0.8) also was present in specimens of prostate carcinoma, endometrial carcinoma, thyroid carcinoma and kidney. Lower levels of AR (0.03-0.1) were detected in adult breast, colon, lung and adrenal gland specimens. This study demonstrates that immunoreactive AR protein is present in a wide variety of human fetal and adult tissues and that two AR isoforms are expressed in many tissues.


Assuntos
Receptores Androgênicos/metabolismo , Adulto , Feto , Humanos , Distribuição Tecidual
20.
Proc Natl Acad Sci U S A ; 90(22): 10690-4, 1993 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-8248161

RESUMO

We isolated cDNAs encoding xanthine dehydrogenase (XD; xanthine:NAD+ oxidoreductase, EC 1.1.1.204) from a human liver cDNA library. The complete nucleotide sequence of human XD was determined; the deduced amino acid sequence encoded a protein of 1336 amino acid residues of M(r) 147,782. Human XD possessed many of the signature sequences typical of XDs from flies and rodents, including an unusual cysteine distribution, a potential 2Fe/2S binding site, and a putative molybdopterin cofactor binding domain. Analysis of potential NAD binding sites suggested a simple hypothesis for the conversion of human XD into the oxygen metabolite forming xanthine oxidase (XO; xanthine:oxygen oxidoreductase, EC 1.1.3.22). Using a human XD complementary RNA hybridization probe, we found a 5100-base RNA in human liver by RNA blot-hybridization analysis. This RNA exhibited tissue-specific distribution that may be pertinent to XD- and XO-mediated oxygen radical injury in ischemia/reperfusion and inflammation. A second 4500-base RNA was detected in some tissues and may arise through differential transcription termination.


Assuntos
Xantina Desidrogenase/genética , Xantina Oxidase/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , DNA Complementar/genética , Dípteros/genética , Drosophila/genética , Expressão Gênica , Genes , Humanos , Dados de Sequência Molecular , RNA Mensageiro/genética , Ratos , Mapeamento por Restrição , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos
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