Growth Processes in Si/Si(111) Epitaxy Observed by Scanning Tunneling Microscopy during Epitaxy.
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Journal Article↗
Biomedical subjects
T Weber
Publications and source records attributed to T Weber.
Diagnosis of Creutzfeldt-Jakob disease by two-dimensional gel electrophoresis of cerebrospinal fluid.
BACKGROUND: The diagnosis of Creutzfeldt-Jakob disease (CJD) is based on clinical and electroencephalographic criteria which do not allow a reliable diagnosis to be made during life. METHODS: Serum and cerebrospinal fluid (CSF) samples were obtained after informed consent from relatives of suspected cases of CJD referred to the German CJD surveillance unit. CSF samples from 58 definite (neuropathologically verified), 46 probable, and 34 possible CJD cases, and from 44 patients without CJD were analysed by two-dimensional gel electrophoresis (2-DE). Two investigators blinded to clinical findings recorded the presence of two proteins, p130/131. The kappa value for the level of agreement between these investigators was calculated. Results obtained were compared with the determination of neuron-specific enolase (NSE) in CSF. NSE concentrations of more than 35 ng/mL were considered indicative of CJD. FINDINGS: p130/131 was detected in 81% of definite (47/58), 80% of probable (37/46), 68% of possible (23/34) CJD cases, and in none of the other 44 cases. NSE concentrations of more than 35 ng/mL were seen in 79% of definite (46/58), 80% of probable (37/46), 59% of possible (20/34) CJD cases, and 9% of other cases (4/43). The positive predictive value for 2-DE of CSF is 100% and the negative predictive value is 69%. The level of agreement for the detection of p130/131 by two evaluators in a subset of 141 2-DE gels was a kappa of 0.93 (95% CI 0.86-0.99). Of 13 cases initially classified as possible and later reclassified as definite, ten cases were identified correctly by the 2-DE analysis, indicating a better diagnostic accuracy of this test compared with the current clinical classification. None of nine cases classified as other by neuropathology had p130/131 in 2-DE. INTERPRETATION: 2-DE for p130/131 is a specific test for the diagnosis of CJD. These data suggest including detection of p130/131 as a criterion for the diagnosis of probable CJD in addition to the currently accepted criteria of a rapidly progressive dementia of less than 2 years duration, typical neurological signs, and periodic sharp-wave complexes in the EEG.
Adult↗
Nucleation and growth of Si/Si(111) observed by scanning tunneling microscopy during epitaxy.
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Journal Article↗
High neuron specific enolase levels in bronchoalveolar lavage fluid of patients with lung carcinoma: diagnostic value, relation to serum neuron specific enolase, and staging.
BACKGROUND: High levels of neuron specific enolase (NSE) have recently been described in the bronchoalveolar lavage (BAL) fluid of patients with lung carcinoma. Although its value in serum has been extensively studied, its diagnostic value in BAL fluid in terms of sensitivity, specificity, and predictive value have not been evaluated. In addition, its value in staging and relation to serum NSE are yet unknown. METHODS: NSE levels were determined on the same day in the BAL fluid and the sera of two groups of patients: those with newly diagnosed lung carcinoma and those with smoking related chronic obstructive pulmonary disease (COPD). Clinical TNM staging was also performed. Levels of NSE in BAL fluid were expressed as nanograms per 100 international units of lactate dehydrogenase. BAL fluid NSE levels of the two groups were compared with staging and serum NSE. RESULTS: A highly significant difference exists in BAL NSE in the two groups. For diagnostic purposes, the simultaneous measurements of serum NSE increases its sensitivity, but specificity remains unchanged. No correlation exists between BAL NSE and serum NSE, tumor size, nodal status, or the presence of metastases. BAL NSE is a better predictor of malignancy than serum NSE. CONCLUSION: BAL fluid measurements of NSE may have diagnostic value, specially if it is simultaneously measured in the serum. However, our study does not show any value for this technique in staging of lung carcinoma. Also it has no correlation with serum NSE. Studies will have to be performed to determine if BAL NSE can predict chemotherapeutic sensitivity.
Aged↗
[Active labor management--the best way to Rome goes via Dublin].
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Female↗
Accuracy and reliability of periodic sharp wave complexes in Creutzfeldt-Jakob disease.
OBJECTIVE: To assess the sensitivity, specificity, and interobserver reliability of periodic sharp wave complexes in the electroencephalograms of patients with Creutzfeldt-Jakob disease. DESIGN: Sixty-eight electroencephalograms in 29 patients who had been suspected of having Creutzfeldt-Jakob disease were reanalyzed by an investigator who was unaware of the clinical data. The incidence of periodic sharp wave complexes in neuropathologically confirmed Creutzfeldt-Jakob disease vs progressive dementia other than Creutzfeldt-Jakob disease was assessed. Blinded electroencephalogram analysis was performed by a second investigator. The interobserver reliability was assessed by the kappa value. SETTING: University hospital, base of the German National Creutzfeldt-Jakob Disease Surveillance Study. PATIENTS: Fifteen patients with neuropathologically confirmed Creutzfeldt-Jakob disease and 14 patients who had been suspected of having Creutzfeldt-Jakob disease because of rapidly progressive dementia but in whom other dementias were diagnosed by unblinded investigators based on clinical and electroencephalographic criteria. MAIN OUTCOME MEASURE: Sensitivity and specificity of periodic sharp wave complexes assessed by their incidence in Creutzfeldt-Jakob disease vs other dementias. Interobserver reliability of periodic sharp wave complexes was expressed by the kappa value. RESULTS: For periodic sharp wave complexes, blinded electroencephalographic analysis resulted in a sensitivity and a specificity of 67% and 86%, respectively. Interobserver reliability was excellent (kappa = 0.95). CONCLUSION: This blinded electroencephalographic study in Creutzfeldt-Jakob disease confirms the high diagnostic value of electroencephalography, as previously reported by open studies.
Aged↗
Apolipoprotein E phenotype frequency and cerebrospinal fluid concentration are not associated with Creutzfeldt-Jakob disease.
OBJECTIVE: To analyze the distribution of apolipoprotein E (Apo E) phenotypes between patients with Creutzfeldt-Jakob disease (CJD) and control subjects. SETTING: University hospital, base of the German National CJD Surveillance Study. DESIGN: Prospective case-control study. SUBJECTS: Sixty-two patients with definite or probable CJD, 90 patients with initial suspected CJO, and 51 controls matched for age, sex, and place of residence. MAIN OUTCOME MEASURES: Phenotyping of Apo E in serum by isoelectric focusing, assessment of the gels by 3 independent investigators, measurement of of Apo E in cerebrospinal fluid using an enzyme-linked immunosorbent assay, and calculation of Kaplan-Meier cumulative survival plots. RESULTS: The most frequent phenotype was E 3-3 with 56% in patients and 59% in controls, followed by E 3-4 with a frequency of 29% vs 25%, respectively. The phenotype E 3-2 was much rarer (13% vs 16%, respectively). Patients with definite CJD had a mean (SD) Apo E concentration of 3.4 (2.0) mg/L; patients with probable CJD, 3.1 (1.6) mg/L; patients with possible CJD, 3.8 (2.2) mg/L; and subjects with other diseases, 3.0 (1.7) mg/L. Mean (SD) disease duration for patients with E 3-2 was 11.8 (9.8) months; for patients with E 3-3, 12.0 (9.02) months; and for patients with E 3-4, 14.2 (12.3) months. CONCLUSIONS: We found no significant difference in the distribution of Apo E phenotypes between patients with CJD and controls. The concentration of Apo E in cerebrospinal fluid cannot be taken as a biochemical marker for the disease. The Apo E phenotype had no influence on the duration of CJD. Our data do not support an association of Apo E4 with either the duration or time at onset of CJD.
Adult↗
Pentoxifylline, a phosphodiesterase inhibitor, induces immune deviation in patients with multiple sclerosis.
The outcome of immune responses can be predicted by the lymphokine production pattern of the participating cells. Cytokines of the T helper type 1 (Th1) cells mediate inflammatory responses and delayed-type hypersensitivity (DTH), whereas Th2-like T cells predominantly produce cytokines, which stimulate antibody production by B cells. Immunoregulatory therapy of autoimmune diseases with unknown antigens may be achieved by inhibiting the production of inflammatory cytokines and induction of protective cytokines of Th2-like T cells. To determine the immunoregulatory capacity of the phosphodiesterase inhibitor pentoxifylline (PTX), which is known to suppress the production of tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma), this drug was used in mitogen and antigen-stimulated lymphocyte cultures as well as in patients with multiple sclerosis. PTX significantly decreased TNF-alpha and interleukin-12 (IL-12), whereas it increased IL-4 and IL-10 production. In addition, PTX inhibited cell proliferation, which was associated with a marked reduction in CD25 (IL-2 receptor alpha-chain) and CD54 (intercellular adhesion molecule-1; ICAM-1) expression. Increasing doses of PTX significantly reduced TNF-alpha and IL-12 mRNA expression of blood mononuclear cells, but increased IL-4 and IL-10 expression in eight patients with relapsing-remitting multiple sclerosis. These results indicate that PTX modulates immune reactions favouring a Th2-like response and may therefore be useful for the treatment of autoimmune diseases with a dominant Th1-like T cell response.
Autoimmune Diseases↗
Fetal and maternal transcutaneous PCO2 levels during labour and the influence of epidural analgesia.
The Departments of Obstetrics and Gynaecology of the Hvidovre University of Copenhagen and the Free University of Amsterdam collaborated in a study on the relationship of maternal and fetal acid-base state in the intrapartum period. Transcutaneous PCO2 levels of mother (tcPCO2m) and fetus (tcPCO2f) were continuously recorded in 52 patients during labour. TcPCO2f and tcPCO2m correlated significantly (r = 0.42, P < 0.002). During the first stage of labour, a rather stable level was found for tcPCO2f (7.7 +/- 1.6 kPa) and tcPCO2m (4.4 +/- 0.8 kPa). TcPCO2m decreased significantly to 3.8 +/- 0.7 kPa (P < 0.01) in the hour before full cervical dilatation, probably due to maternal hyperventilation as a reaction to painful uterine contractions. TcPCO2f likewise showed a tendency to a decrease to a mean value of 7.4 +/- 1.5 kPa. In eight cases epidural analgesia was applied because of painful uterine contractions. Prior to the epidural analgesia, tcPCO2m (3.8 +/- 0.8 kPa) and tcPCO2f (6.7 +/- 1.7 KPa) were significantly lower in this subgroup compared to the total population. After pain relief by application of epidural analgesia, tcPCO2m and tcPCO2f returned to the population mean.
Acid-Base Equilibrium↗
[Patient knowledge concerning anesthesia general practice and the responsibilities of the anesthetist].
In two Austrian university hospitals 104 patients were interviewed on the basis of questionnaires about their knowledge of the role of anaesthetists. Although 93% of the Patients considered anaesthesists to be physicians, major deficits were found regarding the knowledge about the spheres of activities of anaesthetists. 60% of the respondents confined the anaesthetist to the operating theatre. Only 55% considered the anaesthetist responsible for their safe recovery from anaesthesia. Previous anaesthesia showed to have no influence on the knowledge of anaesthesia practice and the role of anaesthetists. To current practice of informing the patient calls for improvement and new approaches. In addition to this further evaluation work on the influence of the mass media and public knowledge about anaesthesia and the anaesthetists' role should be undertaken.
Adolescent↗
The role of laboratory investigation in the diagnosis and management of patients with suspected herpes simplex encephalitis: a consensus report. The EU Concerted Action on Virus Meningitis and Encephalitis.
As effective therapies for the treatment of herpes simplex encephalitis (HSE) have become available, the virology laboratory has acquired a role of primary importance in the early diagnosis and clinical management of this condition. Several studies have shown that the polymerase chain reaction (PCR) of CSF for the detection of herpes simplex virus type 1 (HSV-1) or type 2 (HSV-2) DNA provides a reliable method for determining an aetiological diagnosis of HSE. The use of PCR in combination with the detection of a specific intrathecal antibody response to HSV currently represents the most reliable strategy for the diagnosis and monitoring of the treatment of adult patients with HSE. The use of these techniques has also led to the identification of atypical presentations of HSV infections of the nervous system and permits the investigation of patients who develop a relapse of encephalitic illness after an initial episode of HSE. A strategy for the optimal use of the investigative laboratory in the diagnosis of HSE and subsequent management decisions is described.
Acyclovir↗
Gastrin levels in serum and bronchoalveolar lavage fluid of patients with lung cancer: comparison with patients with chronic obstructive pulmonary disease.
BACKGROUND: The gastrin gene is known to be expressed in all classes of bronchogenic carcinomas. Furthermore, high levels of gastrin have been reported in both the bronchoalveolar lavage (BAL) fluid and serum of patients with lung cancer. Based on these preliminary data a study was conducted to evaluate the usefulness of gastrin measurements in the diagnosis and staging of lung cancer. METHODS: Thirty-five patients with lung cancer (26 non-small cell (NSCLC) and nine small cell (SCLC)) and 25 patients with chronic obstructive pulmonary disease underwent fibreoptic bronchoscopy and BAL. Gastrin levels were determined in both BAL fluid and the serum and compared with each other and with staging. RESULTS: No difference was found between the gastrin levels in the BAL fluid or serum of the study groups. There was no correlation with the stage in NSCLC and no correlation was found between the gastrin levels in the serum and the BAL fluid. A significant difference was seen in gastrin levels in BAL fluid between extensive and limited SCLC (p < 0.05). CONCLUSION: There is no evidence of clinical usefulness for gastrin measurements in lung cancer.
Adult↗
MR imaging of Creutzfeldt-Jakob disease.
PURPOSE: To describe the magnetic resonance (MR) imaging appearance of Creutzfeldt-Jakob disease (CJD). MATERIALS AND METHODS: MR images obtained in 29 patients who died of CJD (aged 53-77 years at death) were retrospectively reviewed by three neuroradiologists blinded to the diagnosis. RESULTS: Moderate to marked bilateral, symmetrically increased signal intensity was demonstrated in the putamen and caudate nucleus on T2- and proton-density-weighted MR images in 23 patients (79%). In six patients (21%), images showed no major signal intensity abnormalities. T1-weighted images revealed no signal intensity abnormalities and no contrast material enhancement. The degree of atrophy in the cortex and basal ganglia corresponded to the time between onset of symptoms and MR imaging. All patients with a disease duration of longer than 4 months had substantial volume loss. CONCLUSION: Although approximately 20% of the patients did not have MR imaging abnormalities, MR imaging did show signal intensity alterations due to gliosis and spongiform changes early in the course of CJD in the remaining 80%. The demonstration of bilateral areas of increased signal intensity that predominantly affected the caudate nuclei and the putamina on long-repetition-time MR images in an elderly patient with rapidly progressive dementia represents a specific finding and clearly should suggest the diagnosis of CJD.
Aged↗
Staging of the mediastinum: value of positron emission tomography imaging in non-small cell lung cancer.
Recent studies have shown limitations of morphological imaging in staging mediastinal lymph node involvement in lung cancer. In contrast to computed tomography (CT), which depends primarily on anatomical imaging features, positron emission tomography (PET) with 18-fluorodeoxyglucose (FDG) depends mainly on the metabolic characteristics of a tissue for the diagnosis of disease. We have performed a prospective study comparing FDG-PET and CT of the thorax in the presurgical assessment of the mediastinum in 50 patients with newly diagnosed non-small cell lung cancer (NSCLC). CT and PET scans were interpreted separately, and results were compared to pathological staging obtained during thoracotomy. Hilar or mediastinal lymph node involvement was present in 58%. In staging for lymph node involvement, CT had a sensitivity of 72% and specificity of 81%, whereas PET had a sensitivity and specificity of 90% and 86%, respectively. When the PET study was compared to histological results, there were four cases showing more advanced mediastinal involvement with PET and four cases showing less involvement with PET. From our preliminary results, we conclude that positron emission tomography with 18-fluorodeoxyglucose is significantly more accurate than computed tomography in the mediastinal staging of non-small cell lung cancer.
Aged↗
Clinical implications of nucleic acid amplification methods for the diagnosis of viral infections of the nervous system.
Amplification of viral nucleic acids from the cerebrospinal fluid (CSF) has considerably improved the diagnosis of several acute, subacute and chronic viral infections of the nervous system. In herpes simplex virus (HSV) encephalitis (HSE) the polymerase chain reaction (PCR) has become the method of choice for the rapid, non invasive diagnosis. Other herpes virus associated diseases which can now be reliably diagnosed are encephalitis, ventriculoencephalitis, polymyeloradiculitis, myelitis and an inflammatory polyradiculoneuropathy caused by cytomegalovirus (CMV), HSV, varicella-zoster virus (VZV) or Epstein-Barr virus (EBV), EBV associated primary B-cell-lymphoma of the brain, acute aseptic meningitis in young adults allied with VZV, and meningoencephalitis with recurrent seizures due to human herpes virus type 6 (HHV-6). In AIDS patients, PCR has helped to differentiate lesions either due to the human immunodeficiency virus (HIV) itself or to opportunistic infections such as progressive multifocal leukoencephalopathy (PML) caused by JC virus (JCV) or CMV related complications. HIV can be detected early in the course of infection in the CSF and the amount of proviral DNA in CSF cells seems to be correlated with the severity and/or progression of neurological signs and symptoms. Acute epidemic aseptic meningitis caused by enterovirus infections can now be reliably diagnosed and typed by reverse transcriptase PCR (RT-PCR). Meningitis cases caused by vaccination with the Jeryl Lynn and Urabe vaccine strain of mumps virus have been identified using RT-PCR and sequencing of the amplified products (amplicon).
Central Nervous System↗
[Acute tubulo-interstitial nephropathy with uveitis: apropos of case].
We report another case of acute interstitial nephritis with uveitis (TINU syndrome) in a 35-year-old woman. About thirty cases were described since the first ones 20 years ago. We discuss the assessment needed to reach the diagnosis. The evolution is unusually favourable with steroid therapy.
Adult↗
[How I examine... positron-emission tomography in suspected bronchopulmonary cancer].
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Bronchial Neoplasms↗
[Positron emission tomography in the evaluation of intrathoracic lymphatic extension of non-small cell bronchial cancer. A preliminary study of 30 patients].
Current methods for evaluating the mediastinum include chest radiography, computed tomography (CT) or magnetic resonance (MR) imaging and mediastinoscopy. Despite advances in morphologic imaging, some lung cancer patients are found to have unresectable disease at surgery. In contrast to CT scan or MR imaging, which depend primarily on anatomic and morphological criteria, positron emission tomography (PET) with 18fluorodeoxyglucose (FDG) depends mainly of the metabolic characteristics of a tissue for the diagnosis of disease. We perform a prospective study to compare FDG-PET and CT of the thorax in the presurgical assessment of the mediastinum in patients with newly diagnosed non-small cell lung cancer. Thirty patients have been included. CT and PET-scans were interpreted separately and results were compared to surgical staging during thoracotomy. In assessing mediastinal involvement, CT scan had a sensitivity of 56% and a specificity of 64%. For diagnosis mediastinal nodal disease, FDG-PET was 87% sensitive and 78% specific. Its positive predictive value was 82%, and the negative value was 83%. In conclusion, our preliminary results show that FDG-PET appears more accurate than CT in staging of mediastinal non-small cell lung cancer.
Adult↗