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T Weber

Publications and source records attributed to T Weber.

At least 37 records · Page 2Linked to original sources
PubMed2004

High-resolution MR imaging of the rat spinal cord in vivo in a wide-bore magnet at 17.6 Tesla.

The objective was to demonstrate the feasibility and to evaluate the performance of high-resolution in vivo magnetic resonance (MR) imaging of the rat spinal cord in a 17.6-T vertical wide-bore magnet. A probehead consisting of a surface coil that offers enlarged sample volume suitable for rats up to a weight of 220 g was designed. ECG triggered and respiratory-gated gradient echo experiments were performed on a Bruker Avance 750 wide-bore spectrometer for high-resolution imaging. With T*2 values between 5 and 20 ms, good image contrast could be obtained using short echo times, which also minimizes motion artifacts. Anatomy of healthy spinal cords and pathomorphological changes in traumatically injured rat spinal cord in vivo could be visualized with microscopic detail. It was demonstrated that imaging of the rat spinal cord in vivo using a vertical wide-bore high-magnetic-field system is feasible. The potential to obtain high-resolution images in short scan times renders high-field imaging a powerful diagnostic tool.

Animals↗
PubMed2004

Complete photo-fragmentation of the deuterium molecule.

All properties of molecules--from binding and excitation energies to their geometry--are determined by the highly correlated initial-state wavefunction of the electrons and nuclei. Details of these correlations can be revealed by studying the break-up of these systems into their constituents. The fragmentation might be initiated by the absorption of a single photon, by collision with a charged particle or by exposure to a strong laser pulse: if the interaction causing the excitation is sufficiently understood, the fragmentation process can then be used as a tool to investigate the bound initial state. The interaction and resulting fragment motions therefore pose formidable challenges to quantum theory. Here we report the coincident measurement of the momenta of both nuclei and both electrons from the single-photon-induced fragmentation of the deuterium molecule. The results reveal that the correlated motion of the electrons is strongly dependent on the inter-nuclear separation in the molecular ground state at the instant of photon absorption.

Journal Article↗
PubMed2004

Observation of parity nonconservation in møller scattering.

We report a measurement of the parity-violating asymmetry in fixed target electron-electron (Møller) scattering: A(PV)=[-175+/-30(stat)+/-20(syst)] x 10(-9). This first direct observation of parity nonconservation in Møller scattering leads to a measurement of the electron's weak charge at low energy Q(e)(W)=-0.053+/-0.011. This is consistent with the standard model expectation at the current level of precision: sin((2)theta(W)(M(Z))((-)MS)=0.2293+/-0.0024(stat)+/-0.0016(syst)+/-0.0006(theory).

Journal Article↗
PubMed2004

Infective endocarditis following orthotopic heart transplantation: 10 cases and a review of the literature.

BACKGROUND: Infective endocarditis is a known complication of cardiac transplantation. However, published information has been limited to case reports and small case series. METHODS: Cardiac transplantation has been performed at Temple University Hospital since 1983. We identified transplant patients with ICD-9 codes for endocarditis or bacteremia. A diagnosis of endocarditis required fulfillment of the Duke criteria and presence of a vegetation. Clinical and microbiologic data were collected. Demographic and survival information were compared with heart transplant recipients without endocarditis. We reviewed all previously published cases using a MEDLINE search. RESULTS: Ten of 659 heart transplant recipients had endocarditis (1.5%, 187 cases per 100,000 person years). Mitral and tricuspid valves were involved predominantly. No patient had aortic valve infection. Patients with tricuspid valve infection had a greater median number of endomyocardial biopsies (n=23) than those with mitral valve infection (n=9, P=0.10). The major pathogens were Staphylococcus aureus (4 cases) and Aspergillus fumigatus (3 cases). Factors associated with S. aureus infection were new hemodialysis catheters, cellulitis, and a contaminated donor organ. All patients with A. fumigatus had antecedent cytomegalovirus viremia and disseminated fungal infection, including endophthalmitis. Endocarditis-related mortality was 80%. Median survival after transplant was 1.4 years in patients with endocarditis, compared with 9.3 years in other heart transplant recipients (P<0.001). CONCLUSIONS: Endocarditis is substantially more common in heart transplant recipients than in general populations. Frequent central venous catheter access and multiple endomyocardial biopsies appear to predispose to infection. Aspergillus is a common pathogen and endocarditis follows infection elsewhere. The prognosis of post-cardiac transplant endocarditis is poor.

Adult↗
PubMed2004

Guidelines for the diagnosis and management of neurological complications of HIV infection.

The spectrum of neurological complications of HIV-infection has remained unchanged through the years, but its epidemiology changed remarkably as a result of the introduction of highly active antiretroviral therapy (HAART). Guidelines for the diagnosis and treatment of cerebral toxoplasmosis, cryptococcal meningitis, progressive multifocal leukoencephalopathy, CMV encephalitis, CMV polyradiculomyelitis, tuberculous meningitis, primary CNS lymphoma, HIV dementia, HIV myelopathy and HIV polyneuropathy are given with a grading of evidence and recommendations.

Anti-HIV Agents↗
PubMed2004

Increased serum concentrations of soluble CD95/Fas and caspase 1/ICE in patients with acute angina.

OBJECTIVES: To investigate the expression of death inducing receptors in the sera of patients with stable and unstable angina. DESIGN: 80 consecutive patients with stable (n = 40) or unstable (n = 40) angina pectoris were studied. Serum concentrations of soluble CD95 (sCD95), soluble CD95 ligand (sCD95L; CD178), tumour necrosis factor (TNF) alpha, soluble TNFalpha receptor type 1 (sTNFR1), and interleukin 1beta converting enzyme (ICE; caspase 1) were measured by enzyme linked immunosorbent assay (ELISA). RESULTS: Significant increases in the concentrations of sCD95 and ICE (p < 0.001 and p < 0.023, respectively) were found in the serum from patients with unstable angina relative to those with stable angina. There were no significant differences in the concentrations of sCD95L, TNF alpha, and sTNFR1 between the groups. CONCLUSIONS: These data provide the first evidence that sCD95 and ICE are important serological markers that may help to discriminate between stable and unstable angina. This observation may warrant further clinical study to elucidate the clinical impact of sCD95 and ICE in acute coronary syndromes.

Acute Disease↗
PubMed2004

Spontaneous coronary artery dissection involving the left main stem: assessment by intravascular ultrasound.

This case report describes the devastating consequences of spontaneous coronary dissection in a 36 year old female patient who otherwise had a normal coronary arteriogram. Intravascular ultrasound showed coronary artery dissection and intramural haematoma at the left main stem coronary artery. Acute coronary syndrome developed and subsequently surgical revascularisation was performed successfully.

Adult↗
PubMed2004

Antiarrhythmic therapy on prevention of postoperative atrial fibrillation in patients after heart surgery.

The incidence of supraventricular arrhythmias is high following open-heart surgery, occurring in 25% to about 50% of patients. The most common of these arrhythmias is atrial fibrillation (AF). Postoperative AF has been associated with increased incidence of other complications and increased hospital length of stay. Atrial arrhythmias are most frequent in the first two to three days after cardiothoracic surgery, but they can occur at any point in the recovery period. Age and concomitant valular heart disease are consistently the independent factors most strongly associated with postoperative atrial fibrillation. Prevention of AF seems to be a reasonable clinical goal, and, consequently, many randomized trials have evaluated the effectiveness of pharmacological and nonpharmacological interventions for prevention of AF. The main indication for AF prophylaxis remains the shorteningof length of hospital stay and possibly reduction in stroke. The optimal treatment strategies for reducing postoperative AF are not well established. Commonly used therapeutic approaches include the use of rate-controlling drugs such as beta-blockers, calcium antagonists, and digoxin. Some pharmacological strategies including beta-blockers, sotalol, and amiodarone have shown to reduce risk of postoperative AF and may reduce length of hospital stay. There is no convincing evidence that reducing postoperative AF reduces stroke. This review summarizes current evidence from randomized controlled trials to estimate the effect of pharmacological and non pharmacologic interventions on the occurrence of AF after open-heart surgery and its effects on postoperative outcome.

Animals↗
PubMed2003

Exploiting the genetic potential of polyketide producing streptomycetes.

Streptomycetes are the most important bacterial producers of bioactive secondary metabolites such as antibiotics or cytostatics. Due to the emerging resistance of pathogenic bacteria to all commonly used antibiotics, new and modified natural compounds are required for the development of novel drugs. In addition to the classical screening for natural compounds, genome driven approaches like combinatorial biosynthesis are permanently gaining relevance for the generation of new structures. This technology utilizes the combination of genes from different biosynthesis pathways resulting in the production of novel or modified metabolites. The basis for this strategy is the access to a significant number of genes and the knowledge about the activity and specificity of the enzymes encoded by them. A joint initiative was started to exploit the biosynthesis gene clusters from streptomycetes. In this publication, an overview of the strategy for the identification and characterization of numerous biosynthesis gene clusters for polyketides displaying interesting functions and particular structural features is given.

Anti-Bacterial Agents↗
PubMed2003

Thyroid function is associated with presence and severity of coronary atherosclerosis.

BACKGROUND: Overt hypothyroidism has been found to be associated with cardiovascular disease. Moreover, subclinical hypothyroidism is a strong indicator of risk for aortic atherosclerosis and myocardial infarction. HYPOTHESIS: We hypothesized that variation of thyroid function within the normal range may influence the presence and severity of coronary atherosclerosis. METHODS: We studied a total of 100 consecutive men and women (59 men, 41 women, age 63.7 +/- 11.0 years) who underwent coronary angiography. Blood was tested for serum thyrotropin concentrations and for free tri-iodothyronine and free thyroxine concentrations. In addition to the assessment of thyroid function, conventional risk factors for coronary artery disease (CAD), clinical characteristics, serum lipid levels, fasting total homocysteine, and angiographic results of coronary artery assessment were obtained. Two experienced cardiologists blinded to clinical and laboratory data reviewed the cinefilms. The severity of CAD was scored as 0 for those with smooth normal epicardial coronary arteries, 0.5 for plaquing (< 50% diameter stenosis), and 1, 2, or 3 for those with single-, double-, or triple-vessel epicardial coronary artery stenosis of > 50%, respectively. RESULTS: The severity of CAD was scored as 0, 0.5, 1, 2, and 3 in 14, 26, 25, 22, and 13 patients, respectively. Higher levels of serum-free thyroid hormone concentrations were associated with decreased severity of coronary atherosclerosis. Serum-free tri-iodothyronine was 2.99 +/- 0.33 pg/ml in patients with a CAD severity score of 0 to 1 and 2.74 +/- 0.49 pg/ml in patients with CAD severity scores of 2 and 3 (p < 0.01). Moreover, serum-free thyroxine concentrations showed a trend toward higher levels in patients with CAD severity score 0 to 1 compared with patients with CAD severity scores 2 and 3 (11.65 +/- 1.87 pg/ml vs. 10.9 +/- 2.3 pg/ml; p = 0.09). Higher levels of serum thyrotropin concentrations were associated with increased severity of coronary atherosclerosis (1.37 +/- 1.02 mU/l vs. 1.98 +/- 2.13 mU/l in patients with CAD severity score 0 to 1 versus CAD severity scores 2 and 3; p = 0.049). When grouped into three subsets according to their serum free tri-iodothyronine levels (< 2.79, 2.8 to 3.09, and +/- 3.1 pg/ml), the prevalence of CAD scores 2 and 3 was significantly higher in the subset of patients with low serum free tri-iodothyronine levels (48.5%) than in the subsets of patients with medium or high tri-iodothyronine concentrations (32.25 and 25%, respectively, p for trend < 0.05). CONCLUSION: These data in patients referred for coronary angiography suggest that variation of thyroid function within the statistical normal range may influence the presence and severity of coronary atherosclerosis.

Adult↗
PubMed2003

[Gait-analytical studies in patients treated by valgus tibial head osteotomy].

So far, the use of imaging methods has been the only way of evaluating unicompartmental gonarthritis caused by malalignment of lower extremity axes and the results of operative correction. Unfortunately, radiological visualization does not give any information about the actual loads on the joint, i.e.the forces and moments acting on it under dynamic conditions. These can be determined by means of gait-analytical measurements. The authors explain how the anomalous loading that occurs in the knee joint in the case of varus gonarthritis can be calculated and assessed. The mean maximum varus moment of knee joints in a group of patients with varus deformity was 0.74 Nm\kg, which was significantly higher than that in a control group (0.63 Nm\kg). Even after correction of the axes, increased maximum moments--some of them independent of the angle of the knee and of the correction angle--were observed in 30% of the cases investigated. These cases were found to be characterized by a predisposition to revarization. Knee joints in which the preoperative varus moment was significantly high or there was a tendency to under-correction were especially likely to show these features. For these reasons, valgus tibial head osteotomies should generally be performed with slight overcorrection. If the preoperative gait analysis has already confirmed that significantly increased varus forces are in play, a definite overcorrection to about 5 degrees beyond the physiological angle should be the aim.

Adult↗
PubMed2003

Hepatitis A IgG seropositivity and coronary atherosclerosis assessed by angiography.

BACKGROUND: Infectious agents, in particular intracellular pathogens that can establish long-term, persistent infection, may play an important role in atherogenesis. We tested the hypothesis that hepatitis A virus (HAV) could be associated with significant coronary artery disease. METHODS: The possible association between HAV infection and angiographically proven coronary artery disease (CAD) was studied. Blood from 218 patients undergoing coronary angiography was tested for serum IgG antibodies to HAV. RESULTS: Of the 218 patients, 178 (81.7%) had anti-HAV IgG antibodies. CAD prevalence was 66.3% in HAV seropositive and 57.5% in HAV seronegative patients (P=0.385). In contrast, the number of infectious pathogens to which an individual has been exposed correlates with CAD. Four or more of the six seromarkers tested for particular infections (HAV, Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus, influenza type A and type B) were positive in 48.8% of patients with CAD and in 31.2% of patients in patients without CAD (P=0.02). CONCLUSIONS: This analysis demonstrated that HAV seropositivity is not a predictor of risk for CAD. HAV infection, therefore, seems not to be associated with CAD. The number of infectious agents to which an individual has been exposed ('infectious burden') correlates with CAD.

Aged↗
PubMed2003

Sustainable urban development in Brisbane City--the Holy Grail?

Impacts from urban stormwater runoff on receiving environments have been well documented, particularly through specific regional scientific studies. Using various local government planning and management elements, urban developments in Brisbane City are now able to address stormwater management in an increasingly holistic context. One key initiative includes facilitating Water Sensitive Urban Design (WSUD) components within an Integrated Water Management Strategy that looks at policy formation, planning strategies, design option, community marketing and acceptance, maintenance programs and finally evaluation of various WSUD approaches. These can include the use of Natural Channel Designs, grassed swales, bio-filtration systems, porous pavements and roofwater tanks in several economic combinations. By linking with the Cooperative Research Centre for Catchment Hydrology, Brisbane City Council has influenced the design of WSUD planning tools and benefited the city with academic inputs into extensive evaluation programs. As well, it has also contributed to the Cooperative Research Centre's research outcomes. These evaluation programs are increasingly providing better understanding of various stormwater quality best management practices throughout Australia. As part of the overall implementation process, active involvement by a range of stakeholders has been crucial. These stakeholders have included internal planning, development assessment and design staff, external consultants, developers, and other local and state government agencies. The latter two groups are assisting in the important task of "regionalisation" of Brisbane City Council's policies and guidelines. Implementation of WSUD initiatives and stormwater re-use strategies under Council's new "Integrated Water Management" agenda are showing some excellent results, suggesting that sustainable urban development is no longer like the search for the Holy Grail.

Conservation of Natural Resources↗
PubMed2003

[Cardiovascular risk factor profiles and angiography results in young patients].

There is a clear correlation between the incidence of coronary artery disease and existing cardiovascular risk factors. Therefore, it is a matter of interest if there is an accumulation of risk factors in younger patients with premature coronary artery disease compared to those without. We evaluated 1708 consecutive patients who underwent coronary angiography at our institution between August 2001 to February 2002; 85 symptomatic patients under the age of 46 were included in our analysis. In 46 patients (54.1%)--mean age 41.5 +/- 3.6 years--a coronary artery disease was documented, in 39 patients (45.9%)--mean age 39.9 +/- 5.6 years (n.s.)--normal coronary arteries were shown at angiography. Regarding the cardiovascular risk factors in young patients with coronary artery disease compared to young patients without we found a family history of premature coronary artery disease in 54.5% versus 43.6% (n.s.), hypercholesterolemia in 56.5% versus 53.8% (n.s.), LDL cholesterol of 138 +/- 40 mg/dl versus 123.3 +/- 27 mg/dl (s.), HDL cholesterol of 39 +/- 9 mg/dl versus 45.6 +/- 12.6 mg/dl (s.), serum triglycerides of 194.6 +/- 114.9 mg/dl versus 162.1 +/- 98.4 mg/dl (n.s.), diabetes mellitus in 15.2% versus 10.3% (n.s.), hypertension in 45.7% versus 46.4% (n.s.), body mass index > 24.9 kg/m2 in 67.4% versus 69.2% (n.s.), cigarette smoking in 54.6% versus 56.4% (n.s.). And finally, a minimum of two of those risk factors was found in 93.5% versus 87.2% (n.s.). Due to the high prevalence of cardiovascular risk factors in both groups it is impossible to reliably predict the incidence of coronary artery disease from those risk factors. This has to be considered while deciding about the indication for coronary angiography.

Adult↗
PubMed2002

Direct probe of the bent and linear geometries of the core-excited Renner-Teller pair states by means of the triple-ion-coincidence momentum imaging technique.

The doubly degenerate core-excited Pi state of CO2 splits into two due to static Renner-Teller effect. Using the triple-ion-coincidence momentum imaging technique and focusing on the dependence of the measured quantities on the polarization of the incident light, we have probed, directly and separately, the linear and bent geometries for the B1 and A1 Renner-Teller pair states, as a direct proof of the static Renner-Teller effect.

Journal Article↗
PubMed2002

Subarachnoid haemorrhage with "Ecstasy" abuse in a young adult.

Abuse of the drugs like amphetamine, cocaine and "Ecstasy" may be complicated by intracerebral, subdural or subarachnoid haemorrhage. Contrary to historical opinion, drug-related intracranial haemorrhage (ICH) is frequently related to an underlying vascular malformation. We report the case of an 18-year-old man with a history of Ecstasy abuse preceding the onset of severe occipital headache. Cerebral computed tomography revealed right-sided subarachnoid haemorrhage and cerebral angiography showed right-sided middle cerebral artery aneurysm of 1 cm diameter. The patient was treated surgically with aneurysm clipping. Three weeks after onset of intracranial haemorrhage, neurological examination demonstrated normal findings. A history of severe headache immediately after using amphetamine, Ecstasy, or cocaine should alert doctors to the possibility of intracerebral haemorrhage. Arteriography should be part of the evaluation of most young patients with stroke or non-traumatic ICH.

Adolescent↗