Search PubMed⌕ Search

Biomedical subjects

J Graf

Publications and source records attributed to J Graf.

At least 19 recordsLinked to original sources
PubMed2007

[Isoniazid intoxication].

HISTORY AND ADMISSION FINDINGS: A 55-year-old woman presented with sustained convulsions after the ingestion of an at first unknown amount of isoniazid, rifampin, ethambutol and alcohol. INVESTIGATION: At admission the patient had a severe metabolic acidosis. Blood tests showed changes caused by the hepatotoxicity of isoniazid. TREATMENT AND COURSE: Because diazepam was not efficacious in controlling the convulsions the patient was intubated. In response to the therapautic measures the convulsions stopped and metabolic acidosis was quickly compensated. Pyridoxine was given intravenously as an antidote. CONCLUSION: The rare intoxication with isoniazid demands immediate administration of pyridoxine and aggressive treatment of the convulsions.

Acidosis↗
PubMed2006

Interface coupling transition in a thin epitaxial antiferromagnetic film interacting with a ferromagnetic substrate.

We report experimental evidence for a transition in the interface coupling between an antiferromagnetic film and a ferromagnetic substrate. The transition is observed in a thin epitaxial NiO film grown on top of Fe(001) as the film thickness is increased. Photoemission electron microscopy excited with linearly polarized x rays shows that the NiO film is antiferromagnetic at room temperature with in-plane uniaxial magnetic anisotropy. The anisotropy axis is perpendicular to the Fe substrate magnetization when the NiO thickness is less than about 15 A, but rapidly becomes parallel to the Fe magnetization for a NiO coverage higher than 25 A.

Journal Article↗
PubMed2006

Elastic scattering susceptibility of the high temperature superconductor Bi2Sr2CaCu2O(8+delta): a comparison between real and momentum space photoemission spectroscopies.

The joint density of states of Bi2Sr2CaCu2O(8+delta) is calculated by evaluating the autocorrelation of the single particle spectral function A(k, omega) measured from angle resolved photoemission spectroscopy (ARPES). These results are compared with Fourier transformed (FT) conductance modulations measured by scanning tunneling microscopy (STM). Good agreement between the two experimental probes is found for two different doping values examined. In addition, by comparing the FT-STM results to the autocorrelated ARPES spectra with different photon polarization, new insight on the form of the STM matrix elements is obtained. This shines new light on unsolved mysteries in the tunneling data.

Journal Article↗
PubMed2005

[Cardiogenic shock in a 61 year old female with recurrent panic attacks].

A 61 year old patient in a severely reduced general condition complaining of epigastric pain was admitted to our emergency room. Because of elevated troponin T and creatine kinase levels and severely reduced left ventricular function as seen in echocardiography as well as negative T-waves in the anterolateral ECG leads we suspected an acute coronary syndrome. The patient underwent coronary angiography after intubation and a coronary artery disease was excluded. The initial therapy included the use of an intraaortic balloon pump, volume and catecholamine administration controlled by a pulmonary artery catheter. Conducting an abdominal ultrasound we detected a mass at the right adrenal gland. The suspected diagnosis of pheochromocytoma was confirmed by elevated catecholamine levels in the urine and a CT scan. After recompensation and subsequent administration of phenoxybenzamine a benign pheochromocytoma was resected. A massive catecholamine secretion due to a pheochromocytoma can lead to a cardiogenic shock and multiple organ failure. In patients with recurrent panic attacks and hypertension a pheochromocytoma should be included in the differential diagnosis.

Adrenal Gland Neoplasms↗
PubMed2005

Identification and characterization of errors and incidents in a medical intensive care unit.

BACKGROUND: To assess the frequency, type, consequences, and associations of errors and incidents in a medical intensive care unit (ICU). METHODS: Two-hundred and sixteen consecutive patients with predominantly cardiovascular and pulmonary disorders admitted between December 2002 and February 2003 were enrolled. Demographic data, SAPS II, and TISS-28 were obtained for all patients. Prior to patient enrolment all staff members (physicians, nurses, physiotherapists) were repeatedly encouraged to make use of the Incident Report Form (IRF) and detailed descriptions on how, why and when to use the IRF were provided. RESULTS: During the observation period of 64 days, 50 errors involving 32 patients (15%) were reported. Patients subjected to errors were more severely ill (SAPS II 42 +/- 25 vs. 32 +/- 18, P < 0.05), had a higher hospital mortality (38% vs. 9%), and a longer ICU stay (11 +/- 18 vs. 3 +/- 5 days, P < 0.05). Gender, age and TISS-28 were equally distributed. Each day of ICU stay increased the risk by 8% (odds ratio 1.078, 95% confidence interval 1.034-1.125, P < 0.001), and by 2.3% per SAPS II point (odds ratio 1.023, 95% confidence interval 1.006-1.040, P < 0.001). The majority of errors and incidents were judged as 'human failures' (73%), and 46 errors and incidents (92%) as 'avoidable'. CONCLUSIONS: The identification and characterization of errors and incidents combined with contextual information is feasible and may provide sufficient background information for areas of quality improvement. Areas with a high frequency of errors and incidents need to undergo process evaluation to avoid future occurrence.

Adult↗
PubMed2005

Telephonic transmission of 12-lead electrocardiograms during acute myocardial infarction.

To test the feasibility of a small and simple system for telephonic transmission of 12-lead electrocardiograms (ECGs), 70 patients with acute coronary syndrome admitted to the cardiac care unit (CCU) were included in a feasibility study. The transmission system consisted of a belt with multiple electrodes, which was positioned around the chest. The ECG signal was sent to a call centre via a standard telephone line. In parallel, a standard 12-lead ECG was recorded on site. In a retrospective analysis, each lead of the transmitted ECG was compared with the on-site 12-lead ECG with regard to ST-segment changes and final diagnosis. In all 37 patients with acute ST-elevation myocardial infarction, the diagnosis was correctly established on the basis of telephone-transmitted ECGs. In 96% of limb and 88% of chest leads, ST elevations which were visible in standard ECGs were correctly displayed on telephonically transmitted ECGs. In the remaining 33 patients no false-positive diagnosis was made using transtelephonic ECG analysis. A control group of 31 patients without apparent heart disease showed high concordance between standard ECGs and telephonically transmitted ECGs. Telephonically transmitted 12-lead ECGs interpreted by a hospital-based internist/cardiologist might allow a rapid and accurate diagnosis of ST-elevation myocardial infarction and may increase diagnostic safety for the emergency staff during prehospital decision making and treatment of acute myocardial infarction.

Acute Disease↗
PubMed2004

An unusual isotope effect in a high-transition-temperature superconductor.

In conventional superconductors, the electron pairing that allows superconductivity is caused by exchange of virtual phonons, which are quanta of lattice vibration. For high-transition-temperature (high-T(c)) superconductors, it is far from clear that phonons are involved in the pairing at all. For example, the negligible change in T(c) of optimally doped Bi2Sr2CaCu2O8+delta (Bi2212; ref. 1) upon oxygen isotope substitution (16O --> 18O leads to T(c) decreasing from 92 to 91 K) has often been taken to mean that phonons play an insignificant role in this material. Here we provide a detailed comparison of the electron dynamics of Bi2212 samples containing different oxygen isotopes, using angle-resolved photoemission spectroscopy. Our data show definite and strong isotope effects. Surprisingly, the effects mainly appear in broad high-energy humps, commonly referred to as 'incoherent peaks'. As a function of temperature and electron momentum, the magnitude of the isotope effect closely correlates with the superconducting gap--that is, the pair binding energy. We suggest that these results can be explained in a dynamic spin-Peierls picture, where the singlet pairing of electrons and the electron-lattice coupling mutually enhance each other.

Journal Article↗
PubMed2004

[Evidence-based intensive care medicine. Practice, use and significance].

The process of evidence-based medicine incorporates structured clinical problem solving aimed at providing an optimal, patient-centred therapeutic approach. Evidence-based medicine is supported by justified therapeutic principles rather than physicians' intuition only. Few of the published articles allow firm conclusions for a rational patient approach. The methodological quality of at least some of these articles is insufficient to guide rational therapy. Thus, critical appraisal of the literature seems mandatory. The following article highlights the process of evidence-based medicine and its implementation in daily clinical practice. Besides the careful analysis of source data, evidence-based medicine warrants the final evaluation of outcomes for process improvement. This can be obtained utilising surrogate parameters, such as organ failure, resource allocation, or quality of life, or crude mortality of the patients. The integration of personal know-how together with sufficient knowledge and critical appraisal of the current literature may finally lead to improved outcomes.

Catheterization, Swan-Ganz↗
PubMed2004

[Shock--what are the basics?].

Shock, derived from the French "choc", is defined as a syndrome precipitated by a systemic derangement in perfusion leading to widespread cellular hypoxia and vital organ dysfunction. There is an apparently mismatch of oxygen delivery and oxygen uptake on the cellular level. Shock is associated with significant morbidity and mortality. Therefore, rational therapy should rely on the allocation to one of the four primary circulatory defects: cardiogenic, obstructive, distributive and hypovolemic shock. Compensatory mechanisms such as activation of the sympathoadrenal axis and neurohumoral mechanisms act to preserve cardiac output and perfusion of the vital organ systems. Lactate acidosis serves as a marker of critical hypoperfusion. Persistent hypoperfusion und ischemia induce a systemic inflammatory response syndrome which may lead to multiple organ dysfunction or even multiple organ failure.

Adrenal Glands↗
PubMed2004

[Hypokalemic paralysis with thyrotoxicosis].

Hypokalemic periodic paralysis as a complication of thyrotoxicosis (thyrotoxic periodic paralysis) most often occurs in east Asian men. It is characterised by recurrent episodes of flaccid paralysis, hypokalemia, and underlying hyperthyroidism. It needs to be distinguished from sporadic and familial forms of periodic hypokalemic paralysis. No disturbances in the acid-base state and no extracorporal potassium loss are present. We report on the typical case of a young Chinese man presenting with hypokalemic periodic paralysis associated with yet unknown Graves' disease. Intravenous substitution of potassium and oral propranolol were administered. Complete remission was achieved after 10 hours. After medical therapy had normalised thyroid hormone levels, no further hypokalemic paralytic attacks occurred.

1-Propanol↗
PubMed2004

Occupation, social support and quality of life in persons with schizophrenic or affective disorders.

BACKGROUND: Most people suffering from severe mental illness (SMI) lack paid employment. This study investigates the relationship between work status and objective as well as subjective quality of life (QoL) in people with SMI. METHODS: The sample consists of 261 subjects (102 women, 159 men) aged 35 (men) and 38 (women) years on average, of whom 158 suffer from a schizophrenic disorder (ICD-10: F2) and 103 were diagnosed as having an affective disorder (ICD-10: F3). Subjective QoL was assessed with the WHOQOL-BREF scale. RESULTS: Subjects with an occupation in general have a larger social network at their disposal and receive more social support. With regard to income, few (12%) of the subjects with a job on the open labour market live below the poverty level, but many (28-38%) of those engaged in sheltered or other work-like activities do. Occupation ameliorates satisfaction with life domains referring to social integration (social relationships, environment), whereas the individual's well-being (psychological, physical) is hardly affected. Social support is an important mediator of the relationship between occupation and subjective QoL. Income is weakly and negatively related to subjective QoL. CONCLUSIONS: Supportive relationships to colleagues at the workplace mainly explain the better subjective QoL of SMI people with an occupation. When designing specific employment possibilities for people with SMI, we should take notice of the social support dimension at the workplace. Mentally ill people have a substantial poverty risk, even when they are working. In particular, payment for sheltered work should be ameliorated.

Adult↗
PubMed2004

QRS prolongation on surface ECG and brain natriuretic peptide as indicators of left ventricular systolic dysfunction.

OBJECTIVE: To determine whether the combination of prolonged QRS duration and brain natriuretic peptide (BNP) levels predicts left ventricular systolic dysfunction (LVSD) with a higher accuracy compared with QRS duration or BNP alone. SETTING: University hospital. METHODS: We studied 128 consecutive patients with suspected cardiac disease. At rest the QRS duration on 12-lead ECG and BNP levels were determined. A left ventricular ejection fraction (LVEF) <50% at echocardiography was defined as LVSD. RESULTS: QRS duration in the LVSD group (n = 66, LVEF 30 +/- 8%) was longer than in the group without LVSD (n = 62, LVEF 60 +/- 5%; QRS 129 +/- 34 vs. 96 +/- 20 ms, P < 0.001). BNP was higher in the LVSD group compared with controls (467 +/- 397 vs. 169 +/- 242 pg mL(-1), P < 0.001). A QRS duration of >0.1, >0.11 or >0.12 s was highly specific (63, 90 and 98%) but less sensitive (84, 81 and 75%) for the prediction of LVSD. A QRS cut-off value of 106 ms was moderately sensitive (65%) but very specific (87%) for the prediction of LVSD, whereas a BNP cut-off value of >84 pg mL(-1) was highly sensitive (89%) but only modestly specific (58%). The positive likelihood ratio for LVSD of abnormal BNP (2.0) and QRS prolongation >0.1 s (2.3) was improved by the combination of both criteria (5.1). In multivariate analysis, BNP and QRS duration were independent predictors of LVSD. CONCLUSIONS: The combination of abnormal BNP and QRS prolongation yields a higher positive likelihood ratio for the detection of LVSD compared with the two criteria alone.

Aged↗
PubMed2004

Low-molecular weight heparins in percutaneous coronary interventions: current concepts, problems, and perspectives.

A growing body of evidence suggests that low molecular weight heparin (LMWH) is at least as effective as unfractionated heparin (UFH) in the medical management of acute coronary syndromes (ACS) including acute myocardial infarction. Several studies support an early invasive as compared to a conservative (non-invasive) approach utilizing percutaneous coronary intervention (PCI) in these patients. During coronary angiography and PCI systemic anticoagulation usually administering UFH should prevent thrombus formation at the catheter equipment and at the site of vessel injury. The widespread use of UFH as the anticoagulant of choice is explained by low costs, easy reversibility and accepted anticoagulant properties. However, the clinical support for the use of UFH in PCI is largely based on retrospective and observational data only. Compared to UFH, LMWH have distinct pharmacological advantages, including ease of administration and usually no need for monitoring. A major drawback of LMWH is the predominant renal clearance which may lead to unpredictable levels of anticoagulation in patients with impaired renal function. Since LMWH constitute an extremely heterogeneous group of drugs each LMWH should be recognized as an individual pharmaceutical compound. Consequently, pharmacodynamic and pharmacokinetic properties of one LMWH must not be extrapolated for other LMWH. A growing body of evidence supports the use of LMWH in ACS, with or without GPIIb/IIIa receptor antagonists, thrombolysis, or PCI. Although in patients undergoing PCI, LMWH have yet not been shown to be superior to UFH they can safely be administered.

Angioplasty, Balloon, Coronary↗
PubMed2003

Patellar hypertension syndrome in adolescence: a three-year follow up.

INTRODUCTION: Anterior knee pain is one of the major causes of knee pain in an adolescent population. It has been suggested that raised intraosseous pressure may play an important role in the development of anterior knee pain in the young patient. MATERIAL AND METHODS: A prospective clinical multicentre study with 27 adolescent patients presenting with anterior knee pain was performed. After failure to respond to conservative treatment, all patients agreed to undergo minimally invasive intraosseous pressure measurements in local anaesthesia. All 27 patients demonstrated a positive "pain provocation test" as a response to increased intrapatellar pressure and were decompressed with a new intraosseous drilling technique. RESULTS: The repeat intraosseous pressure measurement in 27 patients 1 year postoperatively revealed a significant reduction from 43.3+/-13.4 preoperatively to 24.1+/-4.2 mmHg (p<0.001). The pain relief was documented in the form of a reduced VAS from 7.6+/-1.4 to 2.1+/-1.1 cm after 3 years (p<0.001). CONCLUSION: Patients with anterior knee pain and a positive "pain provocation test" were diagnosed as suffering from a hypertension syndrome of the patella. We conclude that simple extraarticular patellar decompression may offer a valuable new form of treatment in this select group of adolescent patients with anterior knee pain.

Arthralgia↗
PubMed2002

Treatment of toxoplasmosis in pregnancy: concentrations of spiramycin and neospiramycin in maternal serum and amniotic fluid.

Toxoplasma infection during pregnancy is widely treated with oral spiramycin to reduce the risk of congenital toxoplasmosis in the infant. Failures of therapy have been observed, however. In this study, a sensitive high-performance liquid chromatography technique was used to measure concentrations of spiramycin and neospiramycin, one of the major metabolites of spiramycin, in maternal serum and amniotic fluid. Samples were obtained from 18 women who underwent amniocentesis for polymerase chain reaction (PCR) diagnosis of fetal infection 5-109 days following the prescription of spiramycin therapy (3 g/day). Concentrations of spiramycin and neospiramycin in both serum and amniotic fluid were highly variable, ranging from nondetectable values to 1 microg/ml. None of the concentrations measured were within the range reported to inhibit growth of the parasite in vitro. Consistent with previous reports, part of the observed variability in maternal and fetal drug concentrations could be explained by individual differences in several pharmacokinetic parameters: intestinal absorption, tissue distribution, cellular uptake, metabolism, transfer across the placenta, drug accumulation in fetal tissue, and maternal and fetal drug elimination. The heterogeneity of the data could also be related to differences in patient compliance with the medication prescribed. By addressing factors that could impair adequate treatment of toxoplasmosis during pregnancy, the data presented call for a larger-scale controlled study to determine individual and diurnal variations in maternal drug levels, patient compliance, and outcomes of the offspring. The activity of neospiramycin against Toxoplasma gondii should be assessed.

Adolescent↗
PubMed2002

Comparison of oesophageal and gastric air tonometry in patients with circulatory failure.

BACKGROUND: Gastric PCO2 measured by balloon tonometry can estimate the adequacy of splanchnic perfusion. However, enteral feeding and gastric content can interfere with gastric PCO2 assessment. Tonometry in other sites of the body could avoid these problems. We therefore tested the hypothesis that oesophageal air tonometry would give results similar to gastric tonometry. METHODS: We studied 20 consecutive patients (mean age 68 (SD 9) [range 49-81] yr, 18 males, SAPS II score 55 (SD 18), ICU mortality 55%) with circulatory disorders during mechanical ventilation in the intensive care unit. Tonometer probes were placed via the nose, one into the stomach and the other in the oesophagus. PCO2 was measured with two automated gas analysers, at admission and 30 min, 1, 2, 3, 32, 40, and 48 h thereafter. RESULTS: One hundred and forty-eight paired measurements were obtained. Gastric PCO2 was greater than oesophageal PCO2 on admission (7.19 (1.43) vs 5.89 (0.73) kPa, P < 0.01) and subsequently. Differences between the measures correlated (r = 0.67) with the mean absolute value, indicating that overestimation increased as gastric PCO2 increased. CONCLUSIONS: Oesophageal PCO2 is less than gastric PCO2, and the difference is greater when gastric PCO2 levels are greater. Air tonometry may not measure regional PCO2 levels in the oesophagus satisfactorily. Other methods and sites for carbon dioxide tonometry should be examined.

Aged↗