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D Becker

Publications and source records attributed to D Becker.

At least 73 records · Page 4Linked to original sources
PubMed2000

Temporal and topographical characterization of language cortices using intraoperative optical intrinsic signals.

We used intraoperative optical imaging of intrinsic signals (iOIS) and electrocortical stimulation mapping (ESM) to compare functionally active brain regions in 10 awake patients undergoing neurosurgical resection. Patients performed two to four tasks, including visual and auditory naming, word discrimination, and/or orofacial movements. All iOIS maps included areas identified by ESM mapping. However, iOIS also revealed topographical specificity dependent on language task. In Broca's area, naming paradigms activated both anterior and posterior inferior frontal gyrus (IFG), while the word discrimination paradigm activated only posterior IFG. In Wernicke's area, object naming produced activations localizing over the inferior and anterior/posterior regions, while the word discrimination task activated superior and anterior cortices. These results may suggest more posterior phonological activation and more anterior semantic activations in Broca's area, and more anterior/superior phonological activation and more posterior/inferior semantic activations in Wernicke's area. Although similar response onset was observed in Broca's and Wernicke's areas, temporal differences were revealed during block paradigm (20-s) activations. In Broca's area, block paradigms yielded a boxcar temporal activation profile (in all tasks) that resembled response profiles observed in motor cortex (with orofacial movements). In contrast, activations in Wernicke's area responded with a more dynamic profile (including early and late peaks) which varied with paradigm performance. Wernicke's area profiles were very similar to response profiles observed in sensory and visual cortex. The differing temporal patterns may therefore reflect unique processing performed by receptive (Wernicke's) and productive (Broca's) language centers. This study is consistent with task-specific semantic and phonologic regions within Broca's and Wernicke's areas and also is the first report of response profile differences dependent on cortical region and language task.

Brain↗
PubMed2000

Restricted TCR V beta gene expression and enterovirus infection in type I diabetes: a pilot study.

AIMS/HYPOTHESIS: High frequencies of T-cell receptor (TCR) V beta 7+ T cells were detected among the lymphocytes isolated from pancreatic islets of children at the onset of Type I (insulin-dependent) diabetes mellitus. We assessed whether a preferential expression of certain TCR V beta gene families could also be detected among the peripheral blood mononuclear cells from diabetic patients. METHODS: T-cell receptor repertoires were evaluated by using a semi-quantitative RT-PCR-based technique and confirmed by FACS analysis in peripheral blood mononuclear cells from diabetic patients before, at and after onset of the disease. These patients were also tested for exposure to enteroviruses by RT-PCR and by measuring titres of enterovirus-specific antibodies of the IgA, IgG, and IgM classes. RESULTS: T-cell receptor V beta 7 gene family values were higher in recently-diagnosed diabetic patients (10.5% +/- 3.7) than in age-matched non-diabetic control subjects (5.1% +/- 1.6) (p < 0.001). In a time-course analysis of people who developed diabetes during clinical monitoring (i.e., converters), T-cell receptor V beta 7 gene expression showed values consistently above 10% (p < 0.0005). Long-standing diabetic patients showed lower percentage of V beta 7 expression compared to values measured at disease onset. In the longitudinal study of the converters, multiple acute enterovirus infections were also detected. These infections appeared to be temporally related to increased percentage of V beta 7 gene transcripts. CONCLUSION/INTERPRETATION: The deviation in the T-cell receptor V beta repertoire among circulating T cells from diabetic patients seems to re-emphasize the importance of enterovirus infections in accelerating the progression of Type I diabetes.

Adolescent↗
PubMed2000

Influence of intercellular junctions on endothelin secretion of human umbilical vein endothelial cells in vitro.

The endothelium plays a pivotal role in the rheological regulation of blood flow by the secretion of vasoactive factors. The interaction between shear forces and the endothelium is determined by the mechanical properties of the endothelial cell layer which are associated with intercellular junctions. Cell-cell contacts could therefore modulate the secretion of vasocative factors in response to rheological stimuli. We investigated the relationship between intercellular junctions and the secretion of the vasoconstrictor peptide endothelin and the coagulation co-factor von Willebrand factor (vWF). Human umbilical vein endothelial cells (HUVECs) were used as in vitro endothelial model system. Intercellular junctions were reversibly disrupted by calcium chelation or hypertonic stress; alternatively, the formation of intercellular junctions was inhibited by culturing the cells in suspension or by plating them in the presence of an inhibitory anti-VE-cadherin antibody. The opening of intercellular junctions was verified by assessing transmonolayer electrical resistance (TMR) and immunofluorescence morphology. The concentration of endothelin and vWF was measured in the cell culture supernatants using specific ELISAs. The secretion of endothelin was inhibited by EGTA (5 mM) and stimulated by incubation with tumor necrosis factor alpha (TNFalpha, 40 ng/ml). Treatment with hypertonic medium (glycerol, 1,200 mosmol/l) for 10 minutes opened intercellular junctions and markedly reduced the secretion of endothelin. HUVECs in suspension culture did not secrete endothelin and failed to respond to TNFalpha, but readily resumed these functions upon forming a new monolayer on plastic. The reconstitution of intercellular junctions after suspension culture could be inhibited using a specific anti-VE-cadherin antibody. This antibody, but not a non-specific anti-human-IgG antibody reduced endothelin secretion. The secretion of von Willebrand Factor was less dependent on intercellular junctions. The opening of intercellular junctions did not induce cell death, since the cells continued to exclude trypan blue. The results of this study suggest a novel and potentially pathophysiologically/clinically relevant correlation between intercellular junctions and the secretion of endothelin in endothelial cells.

Cadherins↗
PubMed2000

Attitudes towards hormone replacement therapy among middle-aged women and men.

OBJECTIVES: To survey the attitudes of middle-aged women and men towards HRT and associated issues. Men were included because of the possible influence of their attitudes on womens decisions to use HRT. METHODS: Two-hundred women and 311 men, (not wife and husbands), between 45 and 55 years of age, from a general population sample, were queried about their attitudes towards menopause and HRT and on their knowledge about side effects of HRT. RESULTS: The men had a more negative attitude towards HRT than the women. Two-thirds of the subjects, mostly women, considered menopause to be a medical issue and not a developmental stage in the life cycle. The most mentioned benefits of HRT were the prevention of osteoporosis and cardiopathy, and the disadvantages were "cancer" and "side effects". The concept of menopause as a medical entity was significantly correlated with a positive attitude towards HRT and whether the responder currently used HRT. CONCLUSIONS: The attitudes of most women and men towards menopause and its psycho-social meaning play a vital role in the decision of whether women should start HRT. Education on HRT should be extended to include men who seem to have a more negative attitude towards HRT and are less informed about its benefits. Our results indicate that a positive attitude to HRT is associated with factual knowledge about its benefits and disadvantages, while a negative attitude is based more on emotional arguments.

Attitude↗
PubMed2000

Parameters of microsomal and cytosolic liver function but not of liver perfusion predict portal vein velocity in noncirrhotic patients with chronic hepatitis C.

Our aim was to compare color-coded Doppler sonography (CCDS) and quantitative testing of liver function (QTLF) in patients with chronic hepatitis C. In all, 74 patients with chronic hepatitis C and mild fibrosis underwent QTLF, which included aminopyrine breath test (ABT), galactose elimination capacity (GEC), sorbitol clearance (SC), and indocyanine green clearance (ICG). Hepatic artery velocity and resistance index (HA-V, HA-RI) as well as portal vein velocity (PV-V) were measured by CCDS. ABT, GEC, and PV-V were significantly reduced, whereas SC1, ICG, HA-V, and HA-RI showed normal levels. There was a significant correlation between reduction in PV-V only with GEC and ABT. QTLF did not correlate with HA-V and HA-RI. In conclusion, in hepatitis C patients with liver fibrosis, ABT and GEC are decreased significantly, which was paralleled by a reduction of PV-V. Unexpectedly SC1 and ICG, the classical hepatic perfusion parameters, do not correlate with the parameters measured by CCDS.

Aged↗
PubMed2000

When she was bad: borderline personality disorder in a posttraumatic age.

The advent of the posttraumatic stress disorder diagnosis has been welcomed by many as a recognition of the circumstances and needs of victimized women. This paper argues that the increasing application of the PTSD label to women formerly diagnosed with borderline personality disorder, rather than resolving the dilemmas inherent in use of the borderline diagnosis, has succeeded instead in further medicalizing women's problems and reproducing the previously existing caste system of diagnosis and treatment.

Adult↗
PubMed2000

[Hepatic Doppler perfusion index--a sensitive screening method for detecting liver metastases?].

UNLABELLED: The sonographic measurement of the Doppler perfusion index (DPI)--the ratio of blood flow in the hepatic artery to total liver blood flow--has been suggested to represent a method of detecting even small liver metastases. AIM: To evaluate the DPI measurement in our patients with liver metastases of colorectal cancer, gastric and bronchial carcinoma. METHOD: 36 patients with liver metastases were compared to 21 control subjects. The hepatic arterial and portal venous blood flows were calculated from the product of the average velocity of flow and the cross-sectional lumen of the vessel. Each measurement was performed three times by two independent examiners. RESULTS: Patients with metastases had a significantly higher hepatic blood flow and a significantly higher DPI (p = 0.0004; M +/- SD 0.23 +/- 0.11; r 0.06-0.52) compared with controls (M +/- SD 0.14 +/- 0.06, r. 0.05-0.26). No significant difference was seen in the portal vein blood flow. The DPI-values measured by the two examiners differed by 25.98% +/- 23.20. CONCLUSION: DPI values in patients with liver metastases differ from those in control subjects due to an increased hepatic arterial blood flow. No clear separation of the two groups was possible because DPI values overlapped. The inter observer agreement in DPI seems clinically acceptable.

Adult↗
PubMed2000

Crushed stents in benign left brachiocephalic vein stenoses.

Two hemodialysis patients presenting with left venous arm congestion due to benign catheter-induced stenosis of the left brachiocephalic vein were treated by angioplasty and stent placement. External compression of the stents was responsible for rapid recurrence of the symptoms. No osseous or vascular malformation could be identified. Mechanical constraints induced by respiratory chest wall motion and aortic arch flow-related pulsation are proposed to explain this observation. This potential hazard should be considered when stent placement into the left brachiocephalic vein is advocated.

Adult↗
PubMed2000

High prevalence of congenital toxoplasmosis in Brazil estimated in a 3-year prospective neonatal screening study.

BACKGROUND: A pilot neonatal screening programme revealed a high (approximately 1 per 4800 live births) prevalence of congenital toxoplasmosis (CT) in the State of Rio Grande do Sul, Brazil. The purpose of this paper was to estimate in a larger prospective study the prevalence of CT in the country. METHODS: At the beginning of the study, an in-house indirect enzyme immunoassay (EIA) was used, to be later replaced with a commercial capture IgM fluorometric enzyme immunoassay (FEIA). Both methods detect specific anti-Toxoplasma gondii IgM-class antibodies eluted from dried blood spots. RESULTS: Of the total of 140,914 samples received from all over the country, 47 cases were identified and confirmed as CT. This finding suggests a prevalence of 1 per 3000 live births. Of the 47 patients, only eight (17%) had clinical manifestations: two had intracranial calcifications, four had retinal scars, one had an intracranial calcification and retinal scars, and one had hepatosplenomegaly with lymphoadenopathy. The testing was paid for by the patients' families who volunteered for the study and gave their informed consent. CONCLUSION: The 3-year prospective study using sensitive detection methods, reliable confirmation, and feedback from clinicians showed that CT has an extraordinarily high prevalence in Brazil, in fact the highest ever reported in the world. Although the long-term efficacy of treatment of CT has not been well documented, in view of the availability of reliable diagnostics, confirmation and monitoring, functional logistics, and networking for screening, the insidious nature of the sequelae and the very high prevalence of the disease, neonatal screening for CT should be considered an alternative to no screening at all.

Animals↗
PubMed2000

Can clinical factors estimate insulin resistance in type 1 diabetes?

An insulin resistance syndrome (IRS) score was developed based on clinical risk factors in adults with childhood-onset type 1 diabetes in the Epidemiology of Diabetes Complications (EDC) Study and was validated using euglycemic-hyperinsulinemic clamp studies. Hypertension, waist-to-hip ratio (WHR), triglyceride and HDL cholesterol levels, family history of type 2 diabetes, and glycemic control were risk factors used to define the score. A score of 1 (lowest likelihood IRS) to 3 (highest likelihood IRS) was assigned for each risk factor. Eligible subjects (n = 24) were recruited from the EDC cohort based on tertile of IRS score. Subjects received an overnight insulin infusion to normalize glucose levels, then underwent a 3-h euglycemic-hyperinsulinemic (60 mU x m(-2) x min(-1)) clamp. Glucose disposal rate (GDR) was determined during the last 30 min of the clamp. The GDR differed significantly by IRS group (9.65 +/- 2.99, 8.02 +/- 1.39, and 5.68 +/- 2.16 mg x kg(-1) x min(-1), P < 0.01). The GDR was inversely correlated with the IRS score (r = -0.64, P < 0.01). Using linear regression, the combination of risk factors that yielded the highest adjusted r2 value (0.57, P < 0.001) were WHR, hypertension, and HbA1. This study found that clinical risk factors can be used to identify subjects with type 1 diabetes who are insulin resistant, and it provides validation of a score based on clinical factors to determine the extent of insulin resistance in type 1 diabetes. This score will be applied to the entire EDC population in future studies to determine the effect of insulin resistance on complications.

Adult↗
PubMed2000

The association of diabetes specialist care with health care practices and glycemic control in patients with type 1 diabetes: a cross-sectional analysis from the Pittsburgh epidemiology of diabetes complications study.

OBJECTIVE: To determine whether diabetes care characteristics and glycemic control differ by use of specialist care in a representative cohort of patients with type 1 diabetes. RESEARCH DESIGN AND METHODS: Health care, sociodemographic characteristics, and glycemic control were compared between participants in the Pittsburgh Epidemiology of Diabetes Complications Study who reported receiving specialist care (n = 212) and those who did not (n = 217). Specialist care was defined as having received care from an endocrinologist or diabetologist or diabetes clinic attendance during the last year. RESULTS: Patients who reported receiving specialist care were more likely to be female, to have an education level beyond high school, to have an annual household income >$20,000, and to have health insurance. Additionally, patients receiving specialist care were more likely to have received diabetes education during the previous 3 years, to have knowledge of HbAlc testing and to have received that test during the previous 6 months, to have knowledge of the Diabetes Control and Complications Trial results, to self-monitor blood glucose, and to inject insulin more than twice daily. A lower HbA1 level was associated with specialist care versus generalist care (9.7 vs. 10.3%; P = 0.0006) as were higher education and income levels. Multivariate analyses suggest that the lower HbA1 levels observed in patients receiving specialist care were restricted to patients with an annual income >$20,000. CONCLUSIONS: Specialist care was associated with higher levels of participation in diabetes self-care practices and a lower HbA1 level. Future efforts should research and address the failure of patients with low incomes to benefit from specialist care.

Adult↗
PubMed2000

Targets and reality: a comparison of health care indicators in the U.S. (Pittsburgh Epidemiology of Diabetes Complications Study) and Hungary (DiabCare Hungary).

OBJECTIVE: In the U.S., both primary care and specialist physicians share in the care of type 1 diabetic patients, often in an informal collaboration. In Hungary, however, type 1 diabetic patients are generally managed in special centralized diabetes units. These different treatment settings may lead to different health care practices and outcomes. To determine if this is true, diabetes care indicators and complications were compared across representative study populations from the 2 countries. RESEARCH DESIGN AND METHODS: The Pittsburgh Epidemiology of Diabetes Complications Study (EDC) is a prospective cohort of childhood-onset type 1 diabetic patients. DiabCare Hungary, a multicenter cross-sectional study, was developed for quality control purposes and provides a nationwide data set of diabetic patients. We identified 2 comparable populations (EDC, n = 416; DiabCare, n = 405) in terms of age (> or =14 years) and age at onset (<17 years). RESULTS: EDC patients were less likely to receive diabetes education (P<0.0001), see an ophthalmologist (P<0.0001), be treated by diabetologists (P<0.0001), or perform self-monitoring of blood glucose (P<0.0001). They were more likely to use conservative insulin regimens (i.e., 1-2 injections/day, P<0.0001) and have a higher glycated hemoglobin (P< 0.0001). DiabCare patients more often experienced severe hypoglycemia (P<0.01) and had a lower prevalence of proliferative retinopathy (P<0.0001), legal blindness (P<0.05), and albuminuria (> or =30 mg/day P<0.01). No significant differences in macrovascular complications were seen, although rates were generally low CONCLUSIONS: These data suggest that the 2 populations differ by their diabetes care practices, degree of glycemic control, and microvascular complication status.

Adolescent↗
PubMed2000

Optical imaging of bilingual cortical representations. Case report.

The organization of language in the brains of multilingual persons remains controversial. The authors investigated language representations in a proficient bilingual patient by using a novel neuroimaging technique, intraoperative optical imaging of intrinsic signals (iOIS), and a visual object naming task. The results indicate that there are cortical areas that are activated by the use of both English and Spanish languages (superior temporal sulcus, superior and middle temporal gyri, and parts of the supramarginal gyrus). In addition, language-specific areas were identified in the supramarginal (Spanish) and precentral (English) gyri. These results suggest that cortical language representations in bilingual persons may consist of both overlapping and distinct components. Furthermore, this study demonstrates the utility of iOIS in detecting topographical segregation of cognitively distinct cortices.

Adult↗
PubMed2000

Telomerase activity and expression of apoptosis and anti-apoptosis regulators in the progression pathway of human melanoma.

The stages defining the progression pathway of human melanoma are atypical nevi, the precursor lesions and risk markers of melanoma, melanoma in situ and melanoma in the radical growth phase (RGP), which represent the early stages of melanoma development, and primary melanoma in the vertical growth phase (VGP) and melanoma in the metastatic growth phase (MGP), which are the advanced stages of the disease. Unlike cells obtained from VGP and MGP melanomas, which can be established as cell lines, cells derived from atypical nevi, melanoma in situ, and RGP melanoma cannot be propagated in vitro. Thus, information regarding molecular markers that may be differentially expressed in the early versus the advanced stages of this disease can only be obtained from the analysis of specimens. Since activation of telomerase and deregulation of apoptosis contribute to the pathogenesis of a significant number of human malignancies, we conducted a study, using nevus and melanoma specimens, to determine at what stage in the progression pathway of melanoma, telomerase activity can first be detected, and whether concordant with telomerase activation, one might observe a stage-specific switch from expression of promoters to inhibitors of apoptosis. The findings described here, demonstrate telomerase activity in some but not all MGP melanomas and not in any of the preceding pathological stages, and no apparent imbalance between pro- and anti-apoptotic markers in telomerase-positive MGP melanomas compared to telomerase-negative nevi and telomerase-negative VGP and MGP melanomas.

Apoptosis↗