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T Blum

Publications and source records attributed to T Blum.

At least 19 recordsLinked to original sources
PubMed2003

Lattice calculation of the lowest-order hadronic contribution to the muon anomalous magnetic moment.

We present a quenched lattice calculation of the lowest order [O(alpha(2))] hadronic contribution to the anomalous magnetic moment of the muon which arises from the hadronic vacuum polarization. A general method is presented for computing entirely in Euclidean space, obviating the need for the usual dispersive treatment which relies on experimental data for e(+)e(-) annihilation to hadrons. While the result is not yet of comparable precision to those state-of-the-art calculations, systematic improvement of the quenched lattice computation to this level is straightforward and well within the reach of present computers. Including the effects of dynamical quarks is conceptually trivial; the computer resources required are not.

Journal Article↗
PubMed2003

Effect of atrial overdrive pacing on pulmonary vein focal discharge in patients with atrial fibrillation.

AIMS: Recently, it has been shown that atrial fibrillation may be caused by spontaneously discharging foci located predominantly in the pulmonary veins. However, the effect of atrial overdrive pacing on these pulmonary vein foci has not been studied. METHODS AND RESULTS: In 58 patients with drug refractory paroxysmal or persistent atrial fibrillation we performed radiofrequency catheter ablation of arrhythmogenic triggers inside the pulmonary veins and/or an ostial pulmonary vein isolation with conventional mapping and ablation technology. Continuous bigeminal pattern of discharge from one or more arrhythmogenic pulmonary veins was recorded in 14 patients. Atrial overdrive pacing resulted in suppression of pulmonary vein 'focus' activity in all patients. The longest mean atrial pacing cycle length resulting in overdrive suppression was 587+/-114 ms. Independent of pacing rate and duration, bigeminal pulmonary vein focus activity reemerged 2.5+/-3.7s after cessation of pacing. Overdrive suppression of the pulmonary vein focus was incomplete in 9 pacing attempts, and resulted in induction of atrial fibrillation from the same vein in 3 of 31 pacing manoeuvres. At 2 years follow-up 79% of these patients were free of atrial fibrillation, 55% without antiarrhythmic drugs, 24% on previously ineffective antiarrhythmic drug therapy. CONCLUSION: Stable pulmonary vein 'focus' activity in patients with atrial fibrillation can be suppressed by atrial overdrive pacing. However, 'proarrhythmic' effects of atrial overdrive pacing, such as induction of atrial fibrillation, were also seen.

Atrial Fibrillation↗
PubMed2002

No-carrier-added (n.c.a.) synthesis of asymmetric [73,75Se]selenoethers with isonitriles.

A new synthetic pathway for the preparation of no-carrier-added (n.c.a.) [73.75Se]selenoethers was investigated in order to enlarge the scope of available radioselenated compounds. Starting from n.c.a. 73,75Se(0), an isonitrile and an amine, the preparation of appropriate disubstituted radioselenoureas via homogenous and polymer-supported reactions was examined. Alkylation of these intermediates yielded the corresponding [73-75S]selenouronium salts. Hydrolysis under basic conditions provided the [73,75Se]alkylselenolates and a subsequent alkylation yielded various asymmetric [73-75Se]selenoethers with radiochemical yields of 13-56% within a reaction time of 130min in the homogenous phase and 35 min using the polymer-supported synthesis.

Journal Article↗
PubMed2001

Publication rates following pancreas meetings.

Publication rates and determinants of publication were studied based on abstracts presented at pancreatic meetings. All abstracts presented at the 1994 and 1995 annual meetings of the European Pancreatic Club (EPC) and the American Pancreatic Association (APA) were followed up by searching MEDLINE. Publication rates were compared using log-rank tests and multiple logistic regression. The prestige of the publishing journals was compared using Kruskal-Wallis tests on scientific impact factors (SIF). Overall, 340 abstracts were presented at the EPC, and 254 were presented at the APA. Of these, 203 (59.7%, EPC) and 138 (54.3%, APA) were later published in peer-reviewed journals. Publication rates did not differ by study type or country region of origin. In addition, median SIFs were similar by conference (APA vs. EPC) and research type (basic science vs. clinical studies) (overall, 1.7). However, North American and North/West European articles were published in higher impact journals as compared with those from other countries. Publication rates and median journal SIFs in pancreas research are similar to those reported from other medical specialty meetings. There is no difference by conference, type of research, or origin (North American vs. European).

Abstracting and Indexing↗
PubMed2001

Hemoconcentration: an early marker of severe and/or necrotizing pancreatitis? A critical appraisal.

OBJECTIVE: A study was designed to reevaluate hemoconcentration as an early marker of severe and/or necrotizing pancreatitis and compare it against contrast-enhanced CT, the gold standard to diagnose acute necrotizing pancreatitis. METHODS: This prospective study covers the years 1988-1999 for 316 patients (202 male, 114 female) with a first attack of acute pancreatitis. The role of the hematocrit as an early marker of severe and/or necrotizing pancreatitis has been retrospectively evaluated against the prospectively obtained data. They all underwent a CT within 72 h after admission. In addition to the CT-controlled diagnosis of interstitial/necrotizing pancreatitis, the following variables were used to assess severity: initial organ failure according to the Atlanta classification; indication for artificial ventilation and/or dialysis; Ranson score adjusted for etiology; Imrie score; Balthazar score; length of stay in intensive care unit (ICU); total hospital stay; development of pancreatic pseudocysts; indication for operation (necrosectomy); and mortality. Hemoconcentration on admission was defined as a hematocrit level >43.0% for male and >39.6% for female patients. Logistic regression was used to assess the correlation between hemoconcentration and the severity of variables. RESULTS: Hematocrit, as a single parameter measured on admission, had the same sensitivity and negative predictive value as the more complicated Ranson and Imrie scores obtained only after 48 h. However, its specificity, positive predictive value, and total accuracy were lower. Hemoconcentration significantly correlated with the Balthazar score (differential diagnosis between interstitial and necrotizing pancreatitis), stay in ICU, and total hospital stay. Sensitivity and specificity of the hematocrit cut-off level of 43.0% for male and 39.6% for female patients to detect necrotizing pancreatitis were 74% and 45%, respectively. The positive predictive value was 24% and the negative predictive value 88%. Receiver operation characteristics (ROC) curve values for several cut-offs did not result in more ideal levels. CONCLUSION: Hemoconcentration does not significantly correlate with important clinical outcome variables of acute pancreatitis including organ failure and mortality rate. Its prognostic value is comparable to the more complicated Ranson and Imrie scores obtained only after 48 h. The major value of this single easily obtainable and cheap parameter on admission lies in its high negative predictive value. In the absence of hemoconcentration, contrast-enhanced CT may be unnecessary on admission unless the patient does not improve.

Adolescent↗
PubMed2001

Has blood glucose level measured on admission to hospital in a patient with acute pancreatitis any prognostic value?

BACKGROUND: Early detection of pancreatic necrosis allows better management of the disease. Contrast-enhanced computed tomography (CT) as the gold standard for detecting pancreatic necrosis is expensive. AIM OF THE STUDY: This study was to evaluate for the first time whether blood glucose estimation on hospital admission--a simple, cheap, readily available laboratory parameter--may detect pancreatic necrosis and have prognostic value in acute pancreatitis. METHODS: Single blood glucose estimation upon hospital admission was evaluated prospectively for detecting pancreatic necrosis and as a prognostic indicator. The study included 241 nondiabetic patients with a first attack of acute pancreatitis. All underwent CT within 72 h of admission. RESULTS: High blood glucose (> 125 mg/dl) correlated significantly with complex high clinical and biochemical prognostic scores (Ranson, Imrie), a high Balthazar score, pancreatic pseudocysts, and a long hospital stay, but not with organ failure, indication for artificial ventilation, dialysis, surgery, length of intensive care, and mortality. Pancreatic necrosis detection sensitivity of high blood glucose was 83%, specificity 49%, positive predictive value 28%, and negative predictive value 92%. CONCLUSION: A patient with normal blood glucose on admission is unlikely to have pancreatic necrosis. Contrast-enhanced CT would not be needed unless the patient fails to improve.

Acute Disease↗
PubMed2001

Fatal outcome in acute pancreatitis: its occurrence and early prediction.

BACKGROUND/AIMS: This study aims to determine predictability of death in acute pancreatitis at a secondary-care hospital in Germany. METHODS: This study is part of an ongoing study on the epidemiology of acute pancreatitis and covers 368 patients with a first attack of acute pancreatitis in Lüneburg county from 1988 to 1999. Early and late mortality were defined as < or = 1 weeks and > 1 week after admission. The following parameters were used to establish on admission likelihood of death: admission within 24 h or later with an acute attack, abdominal tenderness, signs of peritonitis, amylase and lipase in serum, leukocytes, hematocrit, potassium, sodium, calcium, creatinine after rehydration, blood glucose, bilirubin, serum glutamate-oxalacetate transaminase (SGOT), serum lactate dehydrogenase (SLDH), arterial pO2, APACHE II score, Ranson and Imrie scores. RESULTS: Of the 368 patients 17 (5%) died, 7 early because of multiple organ failure and 10 late because of septic complications. Mortality rates in interstitial and necrotising pancreatitis were 3 and 17%, respectively. Only an elevated serum creatinine (> 2.0 mg/dl) and a blood glucose > 250 mg significantly correlated with mortality. Ranson and Imrie scores were also significantly correlated with mortality; however, they were not obtained on admission, but only after 48 h. In univariate analysis, APACHE II score > or = 6 on admission and lipase > 1,000 U/l on admission provided a high sensitivity and negative predictive value for early and late mortality patients. CONCLUSION: Approximately half of the deaths in acute pancreatitis occur because of multiple organ failure or septic complications. New approaches have to be found to counteract these severe complications. A fatal outcome may be predicted by simple laboratory parameters such as a high serum creatinine and blood glucose. An APACHE II score > or = 6 and a lipase level on admission > or = 1,000 U/l indicate severe pancreatitis.

APACHE↗
PubMed2000

[Focal paroxysmal atrial fibrillation. Experiences with treatment using high frequency catheter ablation].

BACKGROUND AND OBJECTIVE: As has recently been discovered, paroxysmal atrial fibrillation (PAF) can be induced by focal extrasystoles or tachycardia. This raises the question of whether this form of atrial fibrillation can be cured by high-frequency catheter ablation of the focal trigger. PATIENTS AND METHODS: Seven men and eleven women (mean age 45.6 +/- 11 years) with severe symptoms and treatment-resistant PAF underwent electrophysiological tests with the aim of high-frequency catheter ablation, if long-term ECG monitoring had demonstrated frequent atrial extrasystoles or tachycardia as pointer to a focal origin. Ablation was performed at the point of earliest excitation after the origin of the ectopic focus had been localized. The end-point was reached if the atrial ectopic rhythm had ceased for more than 60 min. RESULTS: In 18 of the 20 patients an ectopic focus was found and successfully ablated (1 in the superior vena cava, 3 in the right atrium and 16 in a pulmonary vein). Atrial ectopic beats recurred within 24 hours of ablation in 6 of the 14 patients with a pulmonary vein focus: a second focus was found in two, re-emergence of the original focus in two, no re-investigation in another two. 13 of the 18 patients have had no further symptoms after a mean follow-up of 11 months without anti-arrhythmia treatment. CONCLUSION: The results indicate that focally induced paroxysmal atrial fibrillation can be cured by locally applied high-frequency ablation.

Atrial Fibrillation↗