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Biomedical subjects

K Lenz

Publications and source records attributed to K Lenz.

At least 19 recordsLinked to original sources
PubMed2006

Fate of 5-fluorouracil, doxorubicin, epirubicin, and daunorubicin in hospital wastewater and their elimination by activated sludge and treatment in a membrane-bio-reactor system.

Antineoplastic agents are applied in cancer therapy and end up in hospital wastewater by human excretions. In this study, the raw wastewater of the sewer of the oncologic in-patient treatment ward of the Vienna University Hospital was monitored for 98 d over 2 years for the cytostatics 5-fluorouracil (5-FU), doxorubicin (DOX), epirubicin, and daunorubicin. In a next step, the elimination of the drugs by a membrane-bio-reactor system was investigated. In addition, their fate in wastewater and elimination by activated sludge was investigated with radio-labelled substances. During the monitoring periods, concentration levels ranging from <8.6 to 124 microgl(-1) for 5-FU and from <0.26 to 1.35 microgl(-1) for DOX were determined. The concentrations analysed fitted the lower ranges calculated by an input-output model. Treatment of oncologic wastewater in the membrane bio-reactor as well as the analysis of the effluents of the Vienna University Hospital resulted in concentrations below the limit of detection. Investigations with radio-labelled compounds showed that 5-FU is eliminated from the liquid phase below the limit of detection. But, up to 25% of radio-labelled equivalents of the drug's amount were found in the gaseous phase and only a marginal part in the solid phase, this indicates that at least one part of the drug is biodegraded. For the anthracyclines more than 90% was eliminated from the liquid phase. In this case, adsorption to suspended solids seems to be the major elimination pathway, as up to 30% of the radio-labelled equivalents of the drug's amount was detected in the solid phase. Our results indicate that the investigated anticancer drugs are eliminated by sewage treatment plants, either by biodegradation or adsorption.

Bioreactors↗
PubMed2004

Novel separation method for highly sensitive speciation of cancerostatic platinum compounds by HPLC-ICP-MS.

A high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) method is presented for analysis of cisplatin, monoaquacisplatin, diaquacisplatin, carboplatin, and oxaliplatin in biological and environmental samples. Chromatographic separation was achieved on pentafluorophenylpropyl-functionalized silica gel. For cisplatin, carboplatin, and oxaliplatin limits of detection of 0.09, 0.10, and 0.15 microg L(-1), respectively, were calculated at m/z 194, using aqueous standard solutions. (3 microL injection volume). The method was utilized for model experiments studying the stability of carboplatin and oxaliplatin at different chloride concentrations simulating wastewater and surface water conditions. It was found that a high fraction of carboplatin is stable in ultrapure water and in solutions containing 1.5 mol L(-1) Cl-, whereas oxaliplatin degradation was increased by increasing the chloride concentration. In order to support the assessment of oxaliplatin eco-toxicology, the method was tested for speciation of patient urine. The urine sample contained more than 17 different reaction products, which demonstrates the extensive biotransformation of the compound. In a second step of the study the method was successfully evaluated for monitoring cancerostatic platinum compounds in hospital waste water.

Antineoplastic Agents↗
PubMed2004

[Treating a hypertensive emergency].

A hypertensive crisis is characterized by a massive blood pressure increase of sudden onset, with systolic pressures in excess of 220 mmHg or diastolic pressures of more than 120 mmHg usually being found in patients with underlying hypertensive disease. Of decisive importance for the severity of the patient's presenting state, however, is not the absolute level of the blood pressure, but rather the extent of the acute blood pressure increase. Of decisive importance for the therapeutic approach to the acute case is whether the hypertensive crisis is accompanied by organic manifestations (hypertensive emergency) or is unaccompanied by this life-threatening clinical presentation (hypertensive urgency). The former patients must always be hospitalized, and the preferential treatment is parenteral medication, which is associated with a more rapid and calculable onset of action than can be achieved via the oral or sublingual route.

Antihypertensive Agents↗
PubMed2004

Conjugated bile acid replacement therapy in short bowel syndrome patients with a residual colon.

AIM: To test the efficacy of cholylsarcosine (synthetic conjugated bile acid) and ox bile extracts (mixture of natural conjugated bile acids) on fat absorption, diarrhea, and nutritional state in four short bowel syndrome (SBS) patients with a residual colon not requiring parenteral alimentation. METHODS: The effect of cholylsarcosine (2 g/meal) on steatorrhea and diarrhea was examined in short-term balance studies with a constant fat intake in all four patients. The effect of continuous cholylsarcosine ingestion on nutritional state was assessed by changes in body weight in three patients. In two patients, the effects of cholylsarcosine were compared with those of ox bile extracts. Because of the low incidence rate of SBS this is not a controlled study. RESULTS: In balance studies, cholylsarcosine increased fat absorption from 65.5 to 94.5 g/day (a 44 % increment), an energy gain of 261 kcal/d. Fecal weight increased by 26 %. In two patients natural conjugated bile acids also reduced steatorrhea, but greatly increased diarrhea. As outpatients consuming an unrestricted diet and ingesting cholylsarcosine, three patients gained weight at an average rate of 0.9 kg/week without worsening of diarrheal symptoms. CONCLUSIONS: Cholylsarcosine is efficacious and safe for enhancing fat absorption and nutritional status in short bowel syndrome patients with residual colon. Natural conjugated bile acids improve steatorrhea to a smaller extent and greatly worsen diarrhea.

Aged↗
PubMed2004

Behaviour of bisphenol A (BPA), 4-nonylphenol (4-NP) and 4-nonylphenol ethoxylates (4-NP1EO, 4-NP2EO) in oxidative water treatment processes.

Endocrine disrupting chemicals (EDCs) such as natural and synthetic hormones or industrial chemicals can adversely affect the endocrine system at very low concentrations. As such substances can be present in raw water used for drinking-water production, they potentially pose a health risk to humans. In this study laboratory tests were performed to determine removal efficiencies of selected oxidative drinking water treatment processes, namely ozonation (1.4 mg/l O3) and chlorination, using sodium hypochlorite (0.5 mg/l NaClO) and chlorine dioxide (0.4-0.6 mg/l ClO2) under conditions applied in technical plants. 500-300,000 ng/l of bisphenol A (BPA), 4-nonylphenol (4-NP) and 4-nonylphenol-n-ethoxylates (NPnEO) were selected for investigations and measured by HPLC/FLD and HPLC/MS. To investigate possible oxidation by-products, adsorbable organic halogens (AOX) were determined and estrogenic activities were assessed with the help of an estrogen receptor binding assay (YES). Ozonation and chlorination with ClO2 removed both 4-NP and BPA below detection limits, corresponding with AOX and estrogenic activity. Concerning NPnEO ozonation removed NP1EO and NP2EO up to 28% and 30%, respectively, whereas ClO2 showed high removal efficiencies, eliminating >94% and 92%, respectively. NaCIO removed 4-NP and BPA below detection limits, but estrogenic activities increased and AOX could be measured. NP1EO and NP2EO were only marginally reduced corresponding to the slight decrease of estrogenic potential.

Benzhydryl Compounds↗
PubMed2003

[Acute appendicitis after colonoscopy: causality or coincidence?].

Complications due to diagnostic colonoscopy are very rare. Perforation is the most frequent colon-related event. So far only ten cases of acute appendicitis after colonoscopy have been reported in the literature. We present the case of a 79-year-old man who developed acute appendicitis after diagnostic colonoscopy. Diagnosis was aggravated by the fact that in the patient's history an appendectomy had been performed 65 years earlier. Because of the rarity of this event it is doubtful whether the endoscopic examination was causal or coincidental. However, in cases of pain after colonoscopy, appendicitis has to be included in the differential diagnosis.

Abdomen, Acute↗
PubMed2003

Acute and 3-month treatment effects of candesartan cilexetil on hemodynamics, neurohormones, and clinical symptoms in patients with congestive heart failure.

BACKGROUND: This study evaluated the short-term and long-term effects of the angiotensin II type 1 receptor antagonist candesartan cilexetil on hemodynamics, neurohormones, and clinical symptoms in patients with congestive heart failure (CHF). METHODS: In this multicenter, double-blind, parallel-group study, 218 patients with CHF (New York Heart Association class II or III) with impaired left ventricular function (ejection fraction < or =40%) and pulmonary capillary wedge pressure > or =13 mm Hg were randomly assigned to 12 weeks of treatment with placebo (n = 44) or candesartan cilexetil (2 mg [n = 45], 4 mg [n = 46], 8 mg [n = 39], or 16 mg [n = 44]) once daily after a 2-week placebo run-in period. Hemodynamic measurements were performed by right heart catheterization over a 24-hour period after single (day 1) and repeated (3-month) treatment with the study drug. RESULTS: On regression analysis of the time-response curves, single and multiple doses of candesartan cilexetil produced sustained, significant, and dose-dependent reductions in pulmonary capillary wedge pressure (short-term effect P =.036, long-term effect P =.035) and mean pulmonary arterial pressure (short-term effect P =.031, long-term effect P =.042). Systemic vascular resistance showed a trend toward decreasing with dose on short-term and long-term treatments. No consistent changes were seen in cardiac index. Compensatory increases in plasma renin activity and angiotensin II levels with decreases in aldosterone and atrial natriuretic peptide were dose-dependent and significant. Candesartan cilexetil improved clinical symptoms, stabilized patient New York Heart Association status compared with placebo, and was judged to be an efficacious treatment by the investigators. More patients receiving placebo stopped the trial prematurely because of an adverse event than in any candesartan cilexetil group, and there was no excess of deaths in any treatment group. Candesartan was safe and well tolerated at all dosages. CONCLUSIONS: Candesartan cilexetil demonstrated significant short-term and long-term improvements in hemodynamic, neurohormonal, and symptomatic status and was well tolerated in patients with CHF.

Adolescent↗
PubMed2001

Discriminant validity of the child behaviour checklist CBCL-4/18 in German samples.

This study examined the discriminant validity of the German version of CBCL in two large samples of referred and non-referred children and adolescents which were matched for age, sex and socio-economic status. The combined sample that was used for statistical analysis consists of 2,058 referred and 2,058 non-referred boys and girls between 4 and 18 years of age (mean age: referred boys= 10.9 years, non-referred boys = 10.9 years, referred girls=11.3 years, non-referred girls=11.1 years). Referral status was used as validity criterion. Statistical procedures included Odds Ratios, Total Predictive Values, ROC analyses and discriminant analyses. Results indicated that the discriminant validity of the German version of CBCL is comparable to the original English version. With the use of CBCL Total Problem Score as predictor (cut-off T > or = 60) 83.8% of children and adolescents could correctly be classified (sensitivity 83.6%, specificity 83.9%). Symptoms of the "Attention Problems Scale" show the highest discriminative power to distinguish between disturbed and undisturbed children and adolescents.

Adolescent↗
PubMed2000

Acute renal failure and rhabdomyolysis after inadvertent intra-arterial infusion of excessive doses of epinephrine during cardiopulmonary resuscitation.

Severe renal dysfunction or even acute renal failure necessitating renal replacement therapy are rather infrequent observations in patients following cardiopulmonary resuscitation. A low flow situation alone does not seem to be sufficient for renal breakdown and in addition other factors, such as preexisting renal disease, severe infections or congestive heart failure must be present. We report a patient, in whom during cardiopulmonary resuscitation a central venous catheter was placed which inadvertently was located in the aortic arch. Through this malpositioned line increasing and finally excessive amounts of epinephrine (in total 150 mg) were injected because of inadequate therapeutic response. After finally successful resuscitation the patient developed rhabdomyolysis and acute renal failure, which required hemodialyis therapy. Intraarterial infusion of the vasoconstrictor catecholamine obviously caused a critical reduction in renal and skeletal muscle perfusion. Nevertheless, the patient was discharged from hospital in good neurologic condition and with normal renal function.

Acute Kidney Injury↗
PubMed2000

Intestinal elimination of hydroxyethyl starch?

OBJECTIVE: Hydroxyethyl starch (HES) is mainly eliminated via the kidneys. Any information about extrarenal elimination obtained so far has been either incomplete or contradictory. The objective of this study was to quantify the intestinal excretion of infused HES with a mean molecular weight of 200,000 and a molar substitution of 0.5 (HES 200/0.5) and to compare the reappearance/recovery rate in urine and plasma. DESIGN: Prospective clinical study without control group. SETTING: The study was conducted at the Institute of Hypertension of the Society of Clinical Pharmacology, Vienna, Austria, which is an establishment for research in volunteers. PARTICIPANTS: The results of six out of seven healthy male volunteers were appropriate for analysis. One trial subject had to be excluded from the study because of severe protocol violation (mixing of stool and urine samples). INTERVENTIONS AND METHODS: Each volunteer was administered 500 ml of 10% HES 200/0.5 in a 0.9% NaCl solution intravenously within 1 h. A gut lavage with 6 l of a polysaccharide free solution was continuously administered from 3 h prior to until 2 h after the HES infusion to facilitate the collection of the samples and to exclude any source of error at analysis. HES was quantified with the hexokinase method. MEASUREMENTS AND RESULTS: Right from the beginning of the infusion until 10 h after its completion, the cumulative HES excretion with feces (principle parameter) and urine as well as selective plasma volume and HES plasma level were measured. Six and 14 h after the infusion had been completed, the recovery rates of HES in urine were about 30% and 40%, respectively, and in plasma about 23% and 8%, respectively. By contrast, not more than a kind of "background noise amount" of HES (about 0.2 %) could be recovered in feces ( mean value in % of the infused amount of the substance). Six and 14 h after the infusion had been completed, the total recovery rates of HES were 53% and 49%, respectively. CONCLUSION: In a physiologically unimpaired gut HES 200/0.5 is not, or only to an infinitesimal extent, eliminated via the intestine. The question if there is any alternative path to renal excretion for HES still remains to be answered. As the calculated reappearance/recovery rate of HES is only about 50 % of the administered dose, further investigations as to the final fate of HES appear necessary.

Adult↗
PubMed2000

[Psychosocial stress and its importance for behavioral deviations in juveniles from migrant and German families].

OBJECTIVES: Comparison of the familial, socio-economic and cultural factors among adolescents from German and migrant families; analysis of the risk factors for conspicuous behavior among the adolescents. METHODS: 224 graduates of secondary schools in the Kreuzberg district of Berlin replied to three questionnaires on living situations, psychosocial stress and conspicuous behavior. RESULTS: The living situation of the adolescents from migrant, above all Turkish families as compared to their German counterparts, is characterized by psychosocial disadvantage, but also by a greater stability within the family. Cultural differences are also noted. Risk factors in conjunction with conspicuous behavior included in addition to familial and socioeconomic factors, above all chronic illness, and persecution and discrimination, whereby chronic illnesses were most significantly frequent among the German, while persecution and discrimination were most significantly frequent among the Turkish adolescents. Cultural differences posed no risks for conspicuous behavior.

Adaptation, Psychological↗
PubMed2000

Primary gastric B-cell lymphoma: results of a prospective multicenter study. The German-Austrian Gastrointestinal Lymphoma Study Group.

BACKGROUND & AIMS: Appropriate management of primary gastric lymphoma is controversial. This prospective, multicenter study aimed to evaluate the accuracy of endoscopic biopsy diagnosis and clinical staging procedures and assess a treatment strategy based on Helicobacter pylori status and tumor stage and grade. METHODS: Of 266 patients with primary gastric B-cell lymphoma, 236 with stages EI (n = 151) or EII (n = 85) were included in an intention-to-treat analysis. Patients with H. pylori-positive stage EI low-grade lymphoma underwent eradication therapy. Nonresponders and patients with stage EII low-grade lymphoma underwent gastric surgery. Depending on the residual tumor status and predefined risk factors, patients received either radiotherapy or no further treatment. Patients with high-grade lymphoma underwent surgery and chemotherapy at stages EI/EII, complemented by radiation in case of incomplete resection. RESULTS: Endoscopic-bioptic typing and grading and clinical staging were accurate to 73% and 70%, respectively, based on the histopathology of resected specimens. The overall 2-year survival rates for low-grade lymphoma did not differ in the risk-adjusted treatment groups, ranging from 89% to 96%. In high-grade lymphoma, patients with complete resection or microscopic tumor residuals had significantly better survival rates (88% for EI and 83% for EII) than those with macroscopic tumor residues (53%; P < 0.001). CONCLUSIONS: There is a considerable need for improvement in clinical diagnostic and staging procedures, especially with a view toward nonsurgical treatment. With the exception of eradication therapy in H. pylori-positive low-grade lymphoma of stage EI and the subgroup of locally advanced high-grade lymphoma, resection remains the treatment of choice. However, because there is an increasing trend toward stomach-conserving therapy, a randomized trial comparing cure of disease and quality of life with surgical and conservative treatment is needed.

Adult↗
PubMed2000

Resting energy expenditure in short-term starvation is increased as a result of an increase in serum norepinephrine.

BACKGROUND: The effects of food restriction on energy metabolism have been under investigation for more than a century. Data obtained are conflicting and research has failed to provide conclusive results. OBJECTIVE: The objective of this study was to test the hypothesis that in lean subjects under normal living conditions, short-term starvation leads to an increase in serum concentrations of catecholamines and thus to an increase in resting energy expenditure. DESIGN: Resting energy expenditure, measured by indirect calorimetry, and hormone and substrate concentrations were measured in 11 healthy, lean subjects on days 1, 2, 3, and 4 of an 84-h starvation period. RESULTS: Resting energy expenditure increased significantly from 3.97 +/- 0.9 kJ/min on day 1 to 4.53 +/- 0.9 kJ/min on day 3 (P < 0.05). The increase in resting energy expenditure was associated with an increase in the norepinephrine concentration from 1716. +/- 574 pmol/L on day 1 to 3728 +/- 1636 pmol/L on day 4 (P < 0.05). Serum glucose decreased from 4.9 +/- 0.5 to 3.5 +/- 0.5 mmol/L (P < 0.05), whereas insulin did not change significantly. CONCLUSIONS: Resting energy expenditure increases in early starvation, accompanied by an increase in plasma norepinephrine. This increase in norepinephrine seems to be due to a decline in serum glucose and may be the initial signal for metabolic changes in early starvation.

3-Hydroxybutyric Acid↗
PubMed2000

Short-term prognosis in critically ill patients with liver cirrhosis: an evaluation of a new scoring system.

OBJECTIVE: The mortality of patients with liver cirrhosis admitted to an intensive care unit (ICU) has been found to be high. This study was performed to assess the physiological and laboratory parameters which are able to identify on ICU admission the cirrhotic patients who are most likely to die. DESIGN: Prospective clinical trial. METHODS: Two groups of patients were analysed. Group A consisted of 196 consecutive cirrhotic patients admitted to our medical ICU for various reasons. For the detection of independent outcome predictors, we used a multiple logistic regression model. Based on these variables, the 'intensive care cirrhosis outcome (ICCO) score' was calculated. The ability to discriminate between survivors and non-survivors was determined by receiver operating characteristic curves, and the area under the curve was calculated. Group B consisted of 70 consecutive cirrhotic patients for prospective validation of the ICCO score. RESULTS: Applying multiple logistic regression analysis, bilirubin, cholesterol, creatinine clearance and lactate were found to be independently associated with the hospital mortality. The ICCO score was 0.3707 + (0.0773 x bilirubin (mg/dl)) - (0.00849 x cholesterol (mg/dl)) -(0.0155 x creatinine clearance (ml/min)) + (0.1351 x lactate (mmol/l)), giving an area under a receiver operating characteristic curve of 0.9. Increasing score values were associated with an increase in mortality. All patients with an ICCO score > +2.6 died. CONCLUSIONS: Application of the ICCO score is rapid and available at the patient's bedside, and its application is simple and reproducible. In cirrhotic patients, the ICCO score has a high ability to discriminate between survivors and non-survivors. The ICCO score may facilitate estimation on ICU admission of the prognosis of critically ill cirrhotic patients.

Area Under Curve↗
PubMed1999

Heavy chronic alcohol abuse has no additional adverse effect on the function of extrahepatic organs and ICU mortality in patients with liver cirrhosis.

BACKGROUND AND AIMS: We questioned whether heavy chronic alcohol abuse influences extrahepatic organ failure and ICU mortality in cirrhotic patients admitted to a medical intensive care unit. PATIENTS AND METHODS: Medical records of 208 consecutive cirrhotic critically ill patients were reviewed. Patients were classified into two groups. Group A comprised 144 patients with liver cirrhosis due to heavy chronic alcohol abuse and group B, 64 patients with liver cirrhosis due to non-alcoholic causes. The presence of extrahepatic organ failures in patients of both groups was assessed with parameters determined on the day of admission to the ICU. Furthermore, ICU mortality was determined. RESULTS: The occurrence of extrahepatic organ failure was similar in group A and group B (83% vs. 80%; p = NS). The rate of extrahepatic organ failure was 1.7 +/- 1.2 organs in group A, compared to 1.4 +/- 1 organs in group B (p = NS). ICU mortality was 53% in group A and 44% in group B (p = NS). An increase in the number of extrahepatic organ failures was associated with a concomitant increase in ICU mortality in both groups of patients. CONCLUSION: The occurrence of extrahepatic organ failure and ICU mortality was not different between patients with liver cirrhosis secondary to heavy chronic alcohol abuse and patients with liver cirrhosis due to nonalcoholic causes. Cirrhotic patients should be admitted to a medical intensive care unit for extended intensive care treatment prior to the occurrence of extrahepatic multiple organ failure, independent of the underlying aetiology.

Adult↗
PubMed1999

Aerosolized amphotericin B inhalations as prophylaxis of invasive aspergillus infections during prolonged neutropenia: results of a prospective randomized multicenter trial.

We performed a prospective, randomized, multicenter trial to evaluate the effectiveness of prophylactic inhalations with aerosolized amphotericin B (aeroAmB) to reduce the incidence of invasive aspergillus (IA) infections in patients after chemotherapy or autologous bone marrow transplantation and an expected duration of neutropenia of at least 10 days. From March 1993 until April 1996, 382 patients with leukemias, relapsed high-grade non-Hodgkin lymphomas, or solid tumors were randomized with a 13:10 ratio to receive either prophylactic aeroAmB inhalations at a dose of 10 mg twice daily or no inhalation prophylaxis in an unblinded fashion. The incidence of proven, probable, or possible IA infections was 10 of 227 (4%) in patients who received prophylactic aeroAmB. This did not differ significantly from the 11 of 155 (7%) incidence in patients who received no inhalation prophylaxis (P =.37). Moreover, no differences in the overall mortality (13% v 10%; P =.37) or in the infection-related mortality (8% v 7%; P =.79) were found. In contrast to other nonrandomized trials, we observed no benefit from prophylactic aeroAmB inhalations, but the overall incidence of IA infections was low.

Administration, Inhalation↗