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1.
J Pediatr Urol ; 15(4): 374.e1-374.e5, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31229415

RESUMO

BACKGROUND: The male genital examination is a common source of discomfort for the patient and medical provider. Performance of male genital examination is imperative; however, as many treatable diagnoses can be made. Undescended testicles (UDTs), hernias, testicular tumors, and urethral abnormalities are all potentially concerning findings which can be discovered on routine examination. OBJECTIVE: The objectives of this study are to determine the rate at which general pediatricians perform routine genitourinary (GU) examinations in the pediatric population and to determine the rate at which UDT are diagnosed or documented in the patient's history. The authors hypothesize the rate of pediatric GU examination during routine well-child visits to be in line with the previously reported rates in the adult literature. STUDY DESIGN: Nine hundred ninety-six consecutive male well-child visits conducted by general pediatricians at the study institution were reviewed. These visits were evaluated for documentation of a detailed GU examination as well as the presence of UDT from these examinations. In addition, past medical and surgical histories were reviewed to determine if a diagnosis of UDT was noted. RESULTS: Pediatricians at the study institution documented GU examinations 99.1% of the time during male well-child visits. Only 1.1% of the cohort had a documentation of UDT at any time point. Of the 11 patients with UDT, 6 boys (54.5%) had spontaneous descent with no referral to urology, whereas 5 (45.5%) required orchidopexy. DISCUSSION: Prior reports suggest 70-75% of routine office visits include a genital examination. None of these reports reviewed the pediatric population, thus making this review novel in this respect. In addition, the results are vastly different from these prior studies as the authors demonstrated over 99% of male well-child examinations included documentation of a thorough genital examination. A limitation of the study is its retrospective nature, which creates a lack of standardization across the data set. In addition, without being physically present in the examination room, one cannot discern whether an examination is simply being documented without actual performance because of the template format of the electronic medical record (EMR). Furthermore, the study was not designed to best evaluate the true rate of UDTs; therefore, the reported rate of 1.1% cannot be accurately associated with a particular age at diagnosis. CONCLUSIONS: Pediatricians do, in fact, document GU examinations on a routine basis. This finding cannot be taken with complete certainty as verification of actual examination performance is impractical. While the data demonstrated a lower than expected rate of UDT, depending upon age at diagnosis, this could indicate that although examinations are being documented, their accuracy may be diminished because of various factors at play in the healthcare system as a whole, including improper exam performance and EMR templates. Follow-up studies are required to verify these potentially changing rates of UDT and to determine if there is discordance between documentation and performance of GU examinations.


Assuntos
Atitude do Pessoal de Saúde , Saúde da Criança , Pediatras/estatística & dados numéricos , Exame Físico/estatística & dados numéricos , Sistema Urogenital/anatomia & histologia , Adolescente , Criança , Pré-Escolar , Estudos de Coortes , Bases de Dados Factuais , Documentação/estatística & dados numéricos , Genitália Masculina/anatomia & histologia , Hospitais Pediátricos , Humanos , Incidência , Lactente , Masculino , Avaliação de Resultados em Cuidados de Saúde , Exame Físico/métodos , Padrões de Prática Médica , Estudos Retrospectivos , Centros de Atenção Terciária , Estados Unidos
2.
J Pediatr Urol ; 15(1): 51-57, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30340928

RESUMO

INTRODUCTION: Women are entering the subspecialty of pediatric urology at an accelerated rate. Gender differences affecting fellowship and job selection have been identified in other fields of medicine. OBJECTIVE: The objective of this study was to understand gender differences in pediatric urology fellowship and job selection and how they may affect the workforce. STUDY DESIGN: A 47-question electronic survey consisting of questions regarding demographics, residency training, and factors influencing fellowship and job selection was distributed to current fellows and recent graduates in pediatric urology in May 2017. RESULTS: A total of 111 recent and current fellows were contacted, and 72% completed the survey (55% female [F] and 45% male [M]; 61% current fellows and 39% recent fellows). Respondents rated factors important in choosing pediatric urology on a scale of 1-5 (1, not important and 5, extremely important), and the top three for both genders were 1-working with children, 2-influential mentors, and 3-bread and butter cases such as inguinal orchiopexy. During residency, 93% of respondents reported having influential mentors in pediatric urology. However, mentorship was more important in fellowship choice for males than females (3.6 F, 4.1 M; P-value = 0.048), and 45% reported having only male mentors. Rating factors important in job choice on a scale of 1-5, respondents reported the top factors as 1-rapport with partners/mentorship (4.5), 2-geography/family preferences (4.3), and 3-participation in mentoring/teaching (3.8). Although most job selection criteria were rated similarly between genders, females rated call schedule higher than males (3.5 F, 2.9 M, P-value = 0.009). Although most females and males (79% of F, 78% of M, P-value = 0.868) sought primarily academic positions, a smaller proportion of females accepted academic positions (52% of F, 72% of M, P-value 0.26), and females reported lower satisfaction regarding the availability of jobs on a scale of 1-5 (1, very dissatisfied and 5, very satisfied; 3.1 F, 3.7 M; P-value = 0.034), particularly in academic positions (3.1 F, 3.7 M; P-value = 0.06). This difference was more pronounced in current fellows than recent graduates and may represent a worsening trend. CONCLUSION: Although significant gender differences in fellowship and job selection may exist in other fields, we found that women and men choose pediatric urology fellowships and jobs using similar criteria, which include work-life balance. Gender differences exist in the influence of mentors, indicating a need for more female mentors. While men and women sought similar types of jobs, women were less satisfied with the availability of jobs, particularly academic jobs, than men, which warrants further investigation.


Assuntos
Bolsas de Estudo/estatística & dados numéricos , Pediatria/estatística & dados numéricos , Médicas/estatística & dados numéricos , Urologia/estatística & dados numéricos , Escolha da Profissão , Feminino , Humanos , Masculino , Mentores/estatística & dados numéricos , Autorrelato , Distribuição por Sexo
3.
J Pediatr Urol ; 14(6): 554.e1-554.e6, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30146426

RESUMO

INTRODUCTION: Non-refluxing ureteral reimplantation is favored in pediatric renal transplantation to prevent complications, such as vesicoureteral reflux (VUR) in the transplant ureter. VUR resulting in febrile urinary tract infections remains a problem in this population, leading to repeated hospitalizations and increased morbidity. Revision of the vesicoureteral anastomosis can be a surgical challenge due to scar tissue and tenuous vascularity of the transplant ureter. Therefore, alternative options such as endoscopic injection of Deflux at the neo-orifice and surveillance with prophylactic antibiotics have emerged as potential treatment modalities for transplant ureter VUR. OBJECTIVE: The authors reviewed their experience of the management of VUR in the transplant ureter, comparing outcomes of various modalities. STUDY DESIGN: With Institutional Review Board approval, a retrospective chart review of all renal transplant patients from January 2002 to January 2017 was conducted. All patients with VUR on voiding cystourethrogram (VCUG) after surgery were identified. Indications for end-stage renal disease, urologic comorbidities, pretransplant VCUG, and operative details were recorded. After transplantation, febrile urinary tract infections, ultrasound findings, and any further interventions-surveillance, subureteral endoscopic injection of Deflux, or ureteral reimplantation-were documented along with their outcomes. RESULTS: Overall, VUR was identified in 35/285 (12.3%) transplant patients after a non-refluxing ureteroneocystostomy. VUR was managed with surveillance in 17/35 (49%), intravesical Deflux injection in 11/35 (31%), and immediate redo ureteral reimplantation in 7/35 (20%). Ten out of 11 patients undergoing Deflux injection had a postoperative VCUG. All patients developed VUR recurrence; the majority showed immediate failure and only 1/10 showed late recurrence. Of the immediate failures, 3/9 patients were maintained on prophylactic antibiotics, and 6/9 patients underwent ureteral reimplantation. In these six patients undergoing reimplantation after failed Deflux, 3/6 (50%) patients required additional surgeries: One patient developed recurrence of reflux and two patients developed ureterovesical junction obstruction. In contrast, no complications were seen in patients undergoing primary ureteral reimplantation. DISCUSSION: The study is limited by low numbers and a retrospective design. However, the results of this study differ significantly from the published Deflux series showing a success rate of more than 50% in the treatment of transplant kidney VUR. In fact, post-Deflux redo ureteral reimplantation was associated with an increased risk of postoperative complication. CONCLUSION: The use of Deflux in the post-transplant setting has poor results. In the study series, 11/11 patients demonstrated clinical and radiographic failure. Therefore, as an institution the authors do not recommend Deflux as first-line treatment of VUR in the transplant patient.


Assuntos
Transplante de Rim , Complicações Pós-Operatórias/terapia , Refluxo Vesicoureteral/terapia , Criança , Dextranos/uso terapêutico , Feminino , Humanos , Ácido Hialurônico/uso terapêutico , Masculino , Próteses e Implantes , Estudos Retrospectivos , Resultado do Tratamento
4.
J Pediatr Urol ; 12(5): 294.e1-294.e6, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27160977

RESUMO

INTRODUCTION: Some children who sustain high-grade blunt renal injury may require operative intervention. In the present study, it was hypothesized that there are computed tomography (CT) characteristics that can identify which of these children are most likely to need operative intervention. MATERIALS AND METHODS: A retrospective review was performed of all pediatric blunt renal trauma patients at a single level-I trauma center from 1990 to 2015. Inclusion criteria were: children with American Association for the Surgery of Trauma (AAST) Grade-IV or V renal injuries, aged ≤18 years, and having available CT images with delayed cuts. The CTs were regraded according to the revised AAST grading system proposed by Buckley and McAninch in 2011. Radiographic characteristics of renal injury were correlated with the primary outcome of any operative intervention: ureteral stent, angiography, nephrectomy/renorrhaphy, and percutaneous nephrostomy/drain. RESULTS: One patient had a Grade-V injury and 26 patients had Grade-IV injuries. Nine patients (33.3%) underwent operative interventions. Patients in the operative intervention cohort were more likely to manifest a collecting system filling defect (P = 0.040) (Fig. A) and lacked ureteral opacification (P = 0.010). The CT characteristics, including percentage of devascularized parenchyma, medial contrast extravasation, intravascular contrast extravasation, perirenal hematoma distance and laceration location, were not statistically significant. Of the 21 patients who had a collecting system injury, eight (38.1%) needed ureteral stents. Renorrhaphy was necessary for one patient. Although the first operative intervention occurred at a median of hospital day 1 (range 0.5-2.5), additional operative interventions occurred from day 4-16. Thus, it is prudent to closely follow-up these patients for the first month after injury. Two patients with complex renal injuries had an accessory renal artery resulting in well-perfused upper and lower pole fragments, and were managed nonoperatively without readmission (Fig. B). CONCLUSIONS: Collecting system defects and lack of ureteral opacification were significantly associated with failure of nonoperative management. A multicenter trial is needed to confirm these findings and whether nonsignificant CT findings are associated with operative intervention. In the month after renal injury, these patients should be mindful of any changes in symptoms, and maintain a low index of suspicion for an emergency room visit. For the physician, close follow-up and appropriate counseling of these high-risk patients is advised.


Assuntos
Rim/diagnóstico por imagem , Rim/lesões , Tomografia Computadorizada por Raios X , Ferimentos não Penetrantes/diagnóstico por imagem , Ferimentos não Penetrantes/terapia , Adolescente , Criança , Feminino , Humanos , Escala de Gravidade do Ferimento , Masculino , Estudos Retrospectivos , Falha de Tratamento
5.
JIMD Rep ; 13: 23-6, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24193437

RESUMO

We report a case of false-positive metabolic screening for isovaleric acidemia in a newborn due to treatment of the mother with pivalic acid containing antibiotics before delivery. By using a recently established second-tier test based on the tandem-MS technique, we could identify pivalic acid in a dried blood sample taken during routine neonatal screening. Before this second-tier test was initiated, diverse analytical procedures were performed in the baby to rule out isovaleric acidemia and carnitine supplementation was started. This caused additional psychological burden to the family. The direct use of the second-tier test would have avoided these negative consequences of a false-positive screening result.

6.
Water Sci Technol ; 68(9): 1976-83, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24225097

RESUMO

The entry of pharmaceuticals into the water cycle from sewage treatment plants is of growing concern because environmental effects are evident at trace levels. Ozonation, UV- and UV/H(2)O(2)-treatment were tested as an additional step in waste water treatment because they have been proven to be effective in eliminating aqueous organic contaminants. The pharmaceuticals carbamazepine, ciprofloxacin, diclofenac, metoprolol and sulfamethoxazole as well as the personal care products galaxolide and tonalide were investigated in terms of degradation efficiency and by-product formation in consideration of toxic effects. The substances were largely removed from treatment plant effluent by ozonation, UV- and UV/H(2)O(2)-treatment. Transformation products were detected in all tested treatment processes. Accompanying analysis showed no genotoxic, cytotoxic or estrogenic potential for the investigated compounds after oxidative treatment of real waste waters. The results indicate that by-product formation from ozonation and advanced oxidation processes does not have any negative environmental impact.


Assuntos
Preparações Farmacêuticas/metabolismo , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Poluentes Químicos da Água/toxicidade , Animais , Cromatografia Líquida de Alta Pressão , Monitoramento Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Peróxido de Hidrogênio/química , Oxirredução , Ozônio/química , Preparações Farmacêuticas/análise , Testes de Toxicidade , Águas Residuárias/análise , Poluentes Químicos da Água/análise
7.
J Lipid Res ; 51(6): 1591-8, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20093478

RESUMO

The aim of the study was to develop a method for fast and reliable diagnosis of peroxisomal diseases and to facilitate differential diagnosis of cholestatic hepatopathy. For the quantification of bile acids and their conjugates as well as C(27) precursors di- and trihydroxycholestanoic acid (DHCA, THCA), in small pediatric blood samples we combined HPLC separation on a reverse-phase C18 column with ESI-MS/MS analysis in the negative ion mode. Analysis was done with good precision (CV 3,7%-11.1%) and sufficient sensitivity (LOQ: 11-91 nmol/L) without derivatization. Complete analysis of 17 free and conjugated bile acids from dried blood spots and 10 microL serum samples, respectively, was performed within 12 min. Measurement of conjugated primary bile acids plus DHCA and THCA as well as ursodeoxycholic acid was done in 4.5 min. In blood spots of healthy newborns, conjugated primary bile acids were found in the range of 0.01 to 2.01 micromol/L. Concentrations of C(27) precursors were below the detection limit in normal controls. DHCA and THCA were specifically elevated in cases of peroxysomal defects and one Zellweger patient.


Assuntos
Ácidos e Sais Biliares/sangue , Ácidos e Sais Biliares/química , Análise Química do Sangue/métodos , Coleta de Amostras Sanguíneas , Carbono/química , Soro/química , Atresia Biliar/sangue , Cromatografia Líquida , Galactosemias/sangue , Humanos , Lactente , Recém-Nascido , Modelos Lineares , Transtornos Peroxissômicos/sangue , Espectrometria de Massas em Tandem , Fatores de Tempo , Ácido Ursodesoxicólico/uso terapêutico
8.
Horm Res ; 69(4): 253-6, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18204274

RESUMO

BACKGROUND/AIM: 21-Hydroxylase deficiency congenital adrenal hyperplasia (CAH) is one of the target diseases in many newborn screening programs. 11beta-Hydroxylase defiency is less frequent and does not cause salt-losing crisis. Thus, it is not a target disease for newborn screening. However, affected newborns might show slightly elevated levels of 17-OH-progesterone (17-OHP) in the standard immunoassay screening test. The objective is to show that the diagnosis of 11beta-hydroxylase deficiency can be done using a dried blood spot from newborn screening. CASE REPORT: A male newborn was born at term. Blood sample for newborn screening was taken 36 h after birth. 17-OHP was slightly elevated using time-resolved fluorescence immunoassay (72.8 nmol/l; cut-off <60 nmol/l). RESULTS: We performed second-tier LC-MS/MS from the same blood sample and found elevated levels of 11-deoxycortisol and androstenedione and low cortisol. The family history was positive with an affected older sister born with ambiguous genitalia. Confirmation of diagnosis was done by hormonal analysis and molecular genetic testing of the CYP11B1 gene. A known CYP11B1 gene mutation W116C was identified in this family. CONCLUSIONS: The diagnosis of 11beta-hydroxylase deficiency can be made by second-tier LC-MS/MS from dried blood spots. This method is very helpful in the work-up of elevated immunoassay 17-OHP.


Assuntos
Hiperplasia Suprarrenal Congênita/diagnóstico , Triagem Neonatal/métodos , Esteroide 11-beta-Hidroxilase/metabolismo , Hiperplasia Suprarrenal Congênita/genética , Hiperplasia Suprarrenal Congênita/metabolismo , Cromatografia Líquida , Humanos , Lactente , Recém-Nascido , Masculino , Mutação , Esteroide 11-beta-Hidroxilase/genética , Espectrometria de Massas em Tandem
9.
J Inherit Metab Dis ; 30(4): 610, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17694358

RESUMO

Tyrosinaemia type I, or fumarylacetoacetase deficiency, causes hepatorenal damage by accumulation of fumarylacetoacetate. Patients are generally in good condition at birth, but are at risk of developing serious metabolic crises with liver failure and hepatic coma. An early start of treatment with NTBC and a tyrosine-balanced diet can prevent harm to the patients. The application of tandem mass spectrometry to newborn screening allows for easy determination of tyrosine to detect the presence of hypertyrosinaemia in the neonate, but most patients with tyrosinaemia type I do not present with high tyrosine levels at the time of newborn screening. We report on a 7-week-old girl presenting with acute hepatopathy and severe coagulopathy due to tyrosinaemia type I. The metabolic screening, which was performed by tandem mass spectrometry at the age of 48 h, had revealed normal values for tyrosine and methionine that were well within ranges observed in the general population and equally normal ratios of methionine/tyrosine and tyrosine/serine. In this patient even lowering the cut-off levels for tyrosine and methionine would not have provided better sensitivity. Residual blood spots from the newborn screening filter paper were retrospectively analysed using a specific mass-spectrometric method for the detection of succinylacetone and revealed a 5-fold elevated succinylacetone concentration. This indicates that identification of all newborns with hepatorenal tyrosinaemia is only possible by determination of succinylacetone as part of the newborn screening process.


Assuntos
Heptanoatos/sangue , Triagem Neonatal , Tirosinemias/diagnóstico , Análise Química do Sangue/métodos , Coleta de Amostras Sanguíneas , Feminino , Heptanoatos/análise , Humanos , Lactente , Recém-Nascido , Espectrometria de Massas/métodos , Metionina/sangue , Papel , Sensibilidade e Especificidade , Tirosinemias/sangue
10.
J Clin Endocrinol Metab ; 92(7): 2581-9, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17456574

RESUMO

BACKGROUND: Neonatal screening programs for congenital adrenal hyperplasia (21-CAH) using an immunoassay for 17alpha-hydroxyprogesterone (17-OHP) generate a high rate of positive results attributable to physiological reasons and to cross-reactions with steroids other than 17alpha-OHP, especially in preterm neonates and in critically ill newborns. METHODS: To increase the specificity of the screening process, we applied a liquid chromatography-tandem mass spectrometry method quantifying 17alpha-OHP, 11-deoxycortisol, 21-deoxycortisol, cortisol, and androstenedione. The steroids were eluted in aqueous solution containing d8-17alpha-OHP and d2-cortisol and quantified in multiple reaction mode. RESULTS: Detection limit was below 1 nmol/liter, and recovery ranged from 64% (androstenedione) to 83% (cortisol). Linearity was proven within a range of 5-100 nmol/liter (cortisol, 12.5-200 nmol/liter), and total run time was 6 min. Retrospective analysis of 6151 blood samples and 50 blood samples from newborns with clinically confirmed 21-CAH, as well as prospective analysis of 1609 samples of a total of 242,500 testing positive in our routine 17-OHP immunoassay, allowed clear distinction of affected and nonaffected newborns. High levels of 21-deoxycortisol were only found in children with 21-hydroxylase deficiency. Calculating the ratio of 17alpha-OHP to 21-deoxycortisol divided by cortisol further increased the sensitivity of the method. CONCLUSION: Our liquid chromatography-tandem mass spectrometry procedure as a second-tier test can be used to reduce false-positive results of standard 21-CAH screening. The short total run time of 6 min allows for immediate reanalysis of all immunoassay results above the cutoff.


Assuntos
17-alfa-Hidroxiprogesterona/sangue , Hiperplasia Suprarrenal Congênita/sangue , Hiperplasia Suprarrenal Congênita/diagnóstico , Cortodoxona/sangue , Triagem Neonatal/métodos , 17-alfa-Hidroxiprogesterona/análise , Androstenodiona/análise , Androstenodiona/sangue , Calibragem , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida de Alta Pressão/normas , Cortodoxona/análise , Reações Falso-Positivas , Feminino , Humanos , Hidrocortisona/análise , Hidrocortisona/sangue , Recém-Nascido , Recém-Nascido Prematuro , Masculino , Triagem Neonatal/instrumentação , Triagem Neonatal/normas , Estudos Prospectivos , Reprodutibilidade dos Testes , Estudos Retrospectivos , Espectrometria de Massas em Tandem/métodos , Espectrometria de Massas em Tandem/normas
13.
Fertil Steril ; 74(4): 696-701, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11020509

RESUMO

OBJECTIVE: To investigate the efficacy of using intentionally cryopreserved epididymal sperm in selected cases of obstructive azoospermia. DESIGN: A retrospective, nonrandomized study. SETTING: Academic research environment. PATIENTS: One hundred forty-one couples undergoing first-time IVF/ICSI using either fresh or cryopreserved epididymal sperm. INTERVENTIONS: The epididymides were microsurgically aspirated. MAIN OUTCOME MEASURES: Clinical pregnancy rates. RESULTS: Motile sperm were obtained from all men. For the fresh group, the mean total sperm aspirated was 99 x 10(6) with 5.5 vials frozen per patient after ICSI and 82 x 10(6) with 4.7 vials frozen per patient in the cryopreserved group. No statistically significant difference in oocyte fertilization rate or number of embryos transferred was noted between groups. Of 108 patients using freshly aspirated sperm, 72 (66.7%) achieved clinical pregnancy. Of 33 patients in the group using cryopreserved sperm, 20 (60.6%) achieved clinical pregnancy (P=0.47). CONCLUSIONS: In selected ideal cases of unreconstructable azoospermia, elective open microsurgical epididymal sperm aspiration with cryopreservation yields pregnancy rates similar to that employing fresh sperm. The advantages of this method are: (1) Use of cryopreserved sperm obviates the logistics problems associated with the use of fresh sperm. (2) Abundant high-quality sperm can be cryopreserved in a single procedure for all future attempts at IVF/ICSI. Rarely, viable sperm will not be present after thawing, and fresh retrieval will be necessary.


Assuntos
Fertilização in vitro , Oligospermia , Preservação do Sêmen , Injeções de Esperma Intracitoplásmicas , Criopreservação , Epididimo , Feminino , Humanos , Masculino , Microcirurgia , Gravidez , Resultado da Gravidez , Motilidade dos Espermatozoides
14.
Biochem Pharmacol ; 54(6): 703-11, 1997 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-9310347

RESUMO

Disodium aurothiomalate (AuTM) has been used successfully in the treatment of various autoimmune and inflammatory disorders; however, the molecular target(s) for this agent remains unknown. The aim of this study was to investigate whether the activity of CD45, a protein-tyrosine phosphatase (PTP, EC 3.1.3.48) essential for antigen-receptor-mediated lymphocyte signaling, was modified by AuTM exposure. The effects of AuTM on the activities of CD45 and other PTPs were monitored in vitro by a continuous assay using the substrate fluorescein diphosphate. In addition, the inhibition of PTP1B by AuTM was determined using a novel binding assay that employed an optical biosensor (BIAcore). The experimental results are summarized here: AuTM inhibited CD45 activity with an IC50 of 1.2 +/- 0.1 microM, and inhibition was competitive with substrate. The effect of AuTM, however, was not restricted to CD45, as the cytoplasmic PTP (PTP1B) was also inhibited, with an IC50 of 3.6 +/- 0.2 microM. AuTM also blocked the binding of GST-PTP1B to an immobilized active site inhibitor: a non-hydrolyzable difluorophosphonomethyl phenylalanine-containing biotinylated hexapeptide. AuTM-inhibited CD45 could be reactivated by the addition of excess dithiothreitol. These findings indicate that AuTM may interact with the essential active site cysteine residue involved in the catalytic mechanism of PTPs. Thus, it is possible that some of the cellular effects of gold result from the inhibition of these important cell signaling molecules.


Assuntos
Inibidores Enzimáticos/farmacologia , Tiomalato Sódico de Ouro/farmacologia , Proteínas Tirosina Fosfatases/antagonistas & inibidores , Ligação Competitiva , Glutationa Transferase/genética , Antígenos Comuns de Leucócito/efeitos dos fármacos , Papaína/antagonistas & inibidores , Proteínas Tirosina Fosfatases/genética , Proteínas Recombinantes de Fusão/antagonistas & inibidores
15.
Eur J Clin Chem Clin Biochem ; 31(8): 503-11, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8218583

RESUMO

A method is described for the determination of plasma and serum glycosaminoglycans, which can be used in any laboratory equipped with an HPLC system. It is based on the sequential application of chondroitinases AC and ABC and separation of the resulting disaccharides by high-performance liquid chromatography. All reagents are commercially available. This simple and rapid separation yields an accurate quantification and an exact distribution pattern. The determination of glycosaminoglycan disaccharides is linear between 7 and 7000 mumol/l with coefficients of variation between 3.0 and 7.7% for serum and between 2 and 14% for plasma. The recovery of the assay ranged from 93 to 106% for different concentrations of glycosaminoglycan disaccharides. This HPLC method may therefore be considered as a candidate reference method.


Assuntos
Cromatografia Líquida de Alta Pressão , Glicosaminoglicanos/sangue , Adolescente , Adulto , Condroitina Liases , Cromatografia Líquida de Alta Pressão/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Reprodutibilidade dos Testes , Fatores Sexuais
16.
FEBS Lett ; 273(1-2): 239-42, 1990 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-2172030

RESUMO

Insight into the regulation of the actions of the protein-tyrosine kinases will be greatly facilitated by the full characterization of the family of protein-tyrosine phosphatases. A search for novel phosphatases resulted in the isolation of a cDNA, termed HLPR, encoding a member of the family of human receptor-like protein-tyrosine phosphatases: its cDNA sequence predicts a protein of 793 amino acids (unglycosylated Mr 87,500) and includes a 121 residue extracellular domain, a single transmembrane segment, and and two tandem intra-cytoplasmic catalytic domains. The HLPR genes is located on human chromosome 20, and the protein it encodes likely plays a fundamental role in the physiology of all cells as its expression appears to be ubiquitous.


Assuntos
Cromossomos Humanos Par 20 , Fosfoproteínas Fosfatases/genética , Sequência de Aminoácidos , Sequência de Bases , Carcinoma Hepatocelular , Linhagem Celular , Mapeamento Cromossômico , Clonagem Molecular , DNA de Neoplasias/genética , Biblioteca Gênica , Humanos , Neoplasias Hepáticas , Dados de Sequência Molecular , Proteínas Tirosina Fosfatases , Homologia de Sequência do Ácido Nucleico
17.
Arzneimittelforschung ; 31(9): 1489-97, 1981.
Artigo em Alemão | MEDLINE | ID: mdl-7197962

RESUMO

On the basis of biopharmaceutic-pharmacokinetic and galenic aspects a new sustained-release preparation of theophylline according to the "divided-dose" principle was developed. The technological procedure used allows a reproducible manufacture of a stable product with narrow limits of pharmaceutical quality. The bioavailability of the sustained-release pellets in a dose corresponding to 350 mg active principle is examined in comparison to an aqueous solution or retard-tablet formulation on the marked (containing 260 mg drug/dose), respectively, after single or multiple dose administration to 7 healthy volunteers. The relative bioavailability of the new formulation is about 100%. During chronic application the controlled drug delivery from the sustained-release pellets warrants only slight fluctuations of plasma levels by avoiding peak concentrations. Formulations with a dosage of 200, 350 or 500 mg, respectively, allow adaptation of continuous plasma levels in the therapeutic range between 5--20 micrograms/ml according to the therapeutic necessities of a patient.


Assuntos
Teofilina/administração & dosagem , Adulto , Disponibilidade Biológica , Preparações de Ação Retardada , Estabilidade de Medicamentos , Humanos , Cinética , Masculino , Modelos Biológicos , Teofilina/metabolismo , Fatores de Tempo
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