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Biomedical subjects

J Barth

Publications and source records attributed to J Barth.

At least 19 recordsLinked to original sources
PubMed2006

Protein-Z-deficiency as a rare case of unexpected perioperative bleeding in a patient with spinal cord injury.

STUDY DESIGN: Case report describing the management of repeated perioperative bleeding probably due to Protein-Z-deficiency in a post-traumatic paraplegic patient. OBJECTIVES: To describe the difficulty in diagnosing this rare form of hypocoagulability and the monitoring and substitution concept during three elective surgical interventions. SETTING: Spinal Cord Injury Center, Bergmannstrost, Halle, Germany. CASE REPORT: A 19-year-old male suffering from a post-traumatic paraplegia sub Th8 (ASIA-A) since childhood had experienced two life-threatening intraoperative bleeding incidents before finally Protein-Z-deficiency as the underlying coagulation disorder was diagnosed. After substitution of 2000 IE PPSB (Beriplex P/N) a repeatedly postponed implantation of a sphincter-externus (Brindley-) stimulator could be performed without bleeding complications, and this was also true for two additional urological interventions 1 year later. Protein-Z levels were monitored before, during and after the operations. The preoperative application of between 1000 and 2000 IE PPSB was safe and sufficient to raise the patients' plasma Protein-Z level to almost normal and so prevent excessive intraoperative blood loss. CONCLUSION: In case of repeated bleeding tendency of unknown origin it is mandatory to look for rare causes of hypocoagulability such as Protein-Z-deficiency. We developed a substitution concept using a plasma concentrate with guaranteed Protein-Z amount (PPSB) allowing the safe performance of elective surgical interventions.

Adult↗
PubMed2006

Do intensive care patients need an individualized dosing regimen for levofloxacin?

OBJECTIVE: In general, the pharmacokinetics (PK) of antibiotics in intensive care unit (ICU) patients are known to differ from healthy subjects. These differences can pose challenges in developing appropriate dosing guidelines. The primary objective of this report was to characterize the disposition of levofloxacin in critically ill patients and to assess any relationships between patient covariates and the PK parameters. METHODS: 20 patients in the ICU were given levofloxacin, 500 mg, as an i.v. infusion for a half hour. Plasma samples were taken until 24 hours and assayed using HPLC. The concentration-time data were analyzed using population analysis with NONMEM. RESULTS: The data were described using a 2-compartment model. Creatinine clearance was determined to be a statistically significant predictor of variability in total levofloxacin clearance. For patients with higher levofloxacin clearance, the resulting efficacy for different strains of bacteria (expressed as free AUC/MIC ratios) suggested that for less sensitive pathogens, a dosage adjustment may be needed. CONCLUSION: A model describing the pharmacokinetics of levofloxacin in critically ill patients was developed. It was determined that creatinine clearance has a significant role in the disposition of levofloxacin. This may have significant implications in the clinical setting for identifying optimal dosage regimens for ICU patients.

Anti-Bacterial Agents↗
PubMed2005

Long-term prevention of erosive or ulcerative gastro-oesophageal reflux disease relapse with rabeprazole 10 or 20 mg vs. placebo: results of a 5-year study in the United States.

BACKGROUND: Erosive gastro-oesophageal reflux disease (GERD) is a chronic condition requiring long-term maintenance treatment. However, few trials of proton pump inhibitors in maintaining healing of erosive or ulcerative GERD are conducted for longer than 1 year. AIM: To compare the efficacy and safety of 10- and 20-mg rabeprazole with placebo in the 5-year maintenance of healing in patients previously diagnosed with erosive/ulcerative GERD healed in an acute efficacy trial. METHODS: Patients (N = 497) were randomized to receive once-daily doses of 10- or 20-mg rabeprazole or placebo. The primary efficacy measure was endoscopically documented absence of oesophageal erosions or ulcerations. RESULTS: After 5 years, relapse rates in both rabeprazole groups were significantly lower than with placebo (rabeprazole 20 mg, 11%; 10 mg, 23%; placebo, 63%; P < 0.001 for rabeprazole vs. placebo; P = 0.005 for rabeprazole 20 mg vs. 10 mg). Both rabeprazole doses were significantly superior to placebo in preventing relapse of heartburn frequency and improving patient quality of life. Analyses of adverse events, biopsy findings and laboratory values showed no evidence of clinically significant effects. CONCLUSIONS: Five-year maintenance therapy with rabeprazole is effective in preventing relapse of erosive or ulcerative GERD and is well tolerated.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2005

Interpretation of absorption rate data for inhaled fluticasone propionate obtained in compartmental pharmacokinetic modeling.

OBJECTIVE: Reports characterizing the pharmacokinetics of inhaled fluticasone propionate (FP) using compartmental approaches have suggested that the absorption of FP into the systemic circulation is rapid with a half-life of approximately 10 min. We believe that this is a classical case of misassignment of the pharmacokinetic parameter estimates, a problem often encountered while modeling pharmacokinetic data. The objective of this study was to illustrate and analyze this problem using actual blood level data of FP obtained in 14 healthy subjects. MATERIALS AND METHODS: Serum concentration-time data of FP were obtained from a double-blind, randomized study involving single and multiple twice-daily inhalations of 500 microg via a dry powder device, Diskus. The profiles were fitted using one- and two-compartment pharmacokinetic models with first order absorption. Various permutations of the resulting exponential rate constants were analyzed to determine the combination that was most consistent with the underlying physical process. RESULTS: The two-compartment body model with first order absorption gave excellent fits for the observed FP concentrations after both single and multiple dosing. Even though peak levels were reached relatively early (30 - 90 min) after inhalation, the combination that most appropriately described the underlying process was alpha > Ka > beta, i.e. slow absorption, rapid distribution and slower elimination kinetics. The absorption, distribution and elimination half-lives resulted to be 3.8 h, 9.9 min and 13.6 h, respectively, consistent with the high lipophilicity and sustained dissolution characteristics observed in vitro. CONCLUSIONS: Analysis of FP pharmacokinetics after inhalation represents a classical case of potential misassignment of the exponential rate constants, which if ignored, could lead to erroneous interpretations regarding the underlying process. The study also elucidates the pitfall of using t(max) to calculate absorption rate.

Absorption↗
PubMed2004

Seven-day therapy for Helicobacter pylori in the United States.

BACKGROUND: The ideal duration of Helicobacter pylori treatment in the United States and whether eradication therapy is as successful in nonulcer dyspepsia as in peptic ulcer disease are controversial topics. AIM: This study compared the efficacy of 3-, 7- and 10-day triple therapies with rabeprazole to a 10-day omeprazole control triple therapy for the eradication of Helicobacter pylori in patients with and without peptic ulcer disease in the United States. METHODS: This was a multicentre, double-blind, randomized, parallel-group trial. A total of 803 patients with H. pylori infection (determined by [13C]urea breath test and rapid urease test or culture) received either rabeprazole 20 mg b.d., amoxicillin 1000 mg b.d., and clarithromycin 500 mg b.d. for 3, 7, or 10 days, or 10 days of omeprazole 20 mg b.d. with the same antibiotic regimen (control). H. pylori status was assessed by [13C]urea breath test > or =6 weeks after completing treatment. RESULTS: In intent-to-treat patients, the eradication percentages achieved for the rabeprazole-based treatments were: 3-day, 27% (95% confidence interval: 21%-34%); 7-day, 77% (95% confidence interval: 71%-83%); and 10-day, 78% (95% confidence interval: 72%-84%). The eradication percentage with the 10-day omeprazole-based treatment was 73% (95% confidence interval: 67%-79%). There was no statistically significant difference between the 7-day rabeprazole-based regimen and the 10-day rabeprazole- and omeprazole-based regimens. CONCLUSIONS: Seven-day therapy with rabeprazole, clarithromycin, and amoxicillin is similar in efficacy to 10-day therapies and had similar efficacy in patients with and without ulcer disease.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2004

14C and delta13C characteristics of organic matter and carbonate in saltmarsh sediments from south west Scotland.

The distribution of contaminant radionuclides from the Sellafield nuclear fuel reprocessing plant was used to establish chronologies for three saltmarsh sediment cores from south west Scotland. delta(13)C and (14)C analyses indicated that the cores provided a useful archive record of variations in input of organic matter and carbonate. The results imply that prior to major releases of contaminant (14)C from Sellafield, the (14)C specific activity of organic matter in Irish Sea offshore sediments was about 24 Bq kg(-1) C, while that of the carbonate component was below the limit of detection. These results provide baseline data for modelling the uptake of contaminant (14)C by the Irish Sea sediment system. The study confirmed that small(13)C analyses provide a sensitive means of apportioning the origin of saltmarsh organic matter between C(3) terrigenous plants, C(4) terrigenous plants and suspended particulate marine organic matter. For the <2 mm fraction of sediment, a clear pattern of decreasing marine organic input was observed in response to increasing elevation of the marsh surface as a result of sediment accumulation. Bulk sediment, including detrital vegetation, had a dominant input from terrigenous plants. The combined use of delta(13)C and (14)C data revealed that organic matter in the marine organic component of the <2 mm fraction of contemporary surface sediments of the saltmarshes is dominated by recycled old organic material.

Carbon Radioisotopes↗
PubMed2004

British Cardiac Society Working Group on the definition of myocardial infarction.

The British Cardiac Society commissioned this report to help address inconsistencies in the terminology for acute coronary syndromes and wide variations in the threshold for the diagnosis of myocardial infarction (MI) depending on the assay performed, the precision, and the sensitivity. In addition, several publications have highlighted potential problems with the application of the European Society of Cardiology(ESC)/American College of Cardiology (ACC) consensus document published in 2000. A revision process has been initiated under the guidance of the ESC, the ACC, and the American Heart Association (AHA). The purpose of this report is to help inform the next revision of the ESC/ACC/AHA guidelines for the diagnosis of MI.

Acute Disease↗
PubMed2004

Population pharmacokinetics of methylprednisolone in accident victims with spinal cord injury.

OBJECTIVE: High-dose methylprednisolone (MP) is used to treat acute spinal cord injury (ASCI). The objective of the present study was to determine the pharmacokinetics of the pro-drug methylprednisolone hemisuccinate (MPHS) and MP in accident victims with ASCI. METHODS: The patients (n = 26) were treated with a bolus intravenous loading dose of 30 mg/kg MPHS within 2 h after injury and this was followed by a maintenance infusion of 5.4 mg/kg/h up to 24 h. Blood, CSF and saliva samples were collected up to 48 h after the initial dose and the samples were analyzed by HPLC. Concentration-time data of MPHS and MP were analyzed using population pharmacokinetic analysis with NONMEM software. RESULTS: MPHS and MP could be monitored in plasma and CSF. MP but not MPHS was present in saliva. High variability was seen in the MPHS levels in CSF. The pharmacokinetics of the pro-drug and the metabolite were adequately described by a 2-compartment model with exponential distribution models assigned to the interindividual and the residual variability. At steady state, the average measured MP concentration in plasma was 12.3+/-7.0 microg/ml and 1.74+/-0.85 microg/ml in CSF. The CSF levels of MP could be modeled as a part of the peripheral compartment. CONCLUSION: This study demonstrated that CSF concentrations of MP were sufficiently high after i.v. administration and reflected the concentrations of unbound drug in plasma. Salivary levels of MP were about 32% of the plasma level and may serve as an easily accessible body fluid for drug level monitoring.

Accidents↗
PubMed2003

Rabeprazole is superior to omeprazole for the inhibition of peptone meal-stimulated gastric acid secretion in Helicobacter pylori-negative subjects.

BACKGROUND: Peptone meal-stimulated gastric acid output is considered to be a reliable means to evaluate drug-mediated inhibition of stimulated gastric acid output, an important measure of the efficacy of the agents--such as proton pump inhibitors--used to treat acid-related disorders. AIM: To compare the initial and overall inhibitory effects on peptone meal-stimulated gastric acid secretion of rabeprazole and omeprazole, 20 mg, in Helicobacter pylori-negative subjects on the first and eighth days of treatment. METHODS: Healthy volunteers (n = 27) were randomized in a single-centre, double-blind, double-dummy, 2 x 2 cross-over study. Subjects received an oral dose of rabeprazole or omeprazole, 20 mg once daily, for 8 days. After a 2-4-week washout period, subjects were crossed over to receive the other medication for 8 days. Peptone meal-stimulated gastric acid secretion was measured at hours 11 and 23 at baseline and on days 1 and 8 of treatment. RESULTS: On days 1 and 8, rabeprazole demonstrated a significantly greater inhibition of peptone meal-stimulated gastric acid secretion compared with omeprazole at all time points (P < 0.03). Median values of steady-state inhibition on day 1 were statistically significant at hour 23 (rabeprazole 100% vs. omeprazole 74%, P < 0.02). CONCLUSIONS: Rabeprazole, 20 mg, demonstrated superior control of peptone meal-stimulated gastric acid secretion compared with omeprazole, 20 mg, after the first dose and after the eighth daily dose. Rabeprazole achieved a more rapid onset of acid inhibition and a greater steady-state reduction in peptone meal-stimulated gastric acid secretion.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2003

[Para-articular, periprosthetic fracture in a case with total knee endoprosthesis using the Ilizarov hybrid fixator].

Periprothetic fractures near the knee joint must always be regarded as very severe fractures. Early mobilisation and low stress during surgery are the essential points in deciding which method of surgery to use. The Ilizarov frame can be very successful in individual cases. A hybrid frame can reduce the time of surgery substantially. This method is presented in two case reports.

Aged↗
PubMed2003

[Protein-z-deficiency as a rare case of perioperative bleeding].

Protein Z is a vitamin-K-dependent plasma glycoprotein synthesized by the liver, showing great structural similarity to other vitamin-K-dependent coagulation factors such as factors II, IX, X and protein C and S. Protein Z seems to assist haemostasis by binding thrombin and promoting its association with phospholipid surfaces, and it downregulates coagulation by forming a complex with the plasma protein-Z-dependent protease inhibitor, which inhibits activated factor Xa. Studies in patients with a bleeding tendency of unknown origin during and after surgery displayed diminished protein-Z-concentrations in about 50 % of the patients with recurrent bleeding. We report about a 19 year old patient, who suffers from a posttraumatic paraplegia subTh 8 since childhood. In 1998 a correction operation in order to reduce scoliosis with restrictive ventilatory defects had to be stopped before successful spondylodesis because of massive bleeding. After a second intraoperative bleeding incident and exclusion of other more frequent thrombocytic or plasmatic causes of hypocoagulability protein-Z-deficiency finally was diagnosed. Under substitution of protein-Z using PPSB (Beriplex P/N) a repeatedly postponed implantation of a sphincter-externus (Brindley-) stimulator could be performed without bleeding complications in 2001, and this was also true for two other urological interventions in 2002. This report about repeated life-threatening intraoperative bleeding in a patient with protein-Z-deficiency, which could be successfully counteracted using selected plasma concentrates with guaranteed protein-Z-amounts, underlines the importance of protein-Z-assessment in some rare cases of bleeding tendency of "unknown origin" and documents the preventive plasma Protein-Z-levels achieved with the substitution of PPSB.

Adult↗
PubMed2002

[Comorbidity of depressive disorders and cardiovascular diseases. Implications for diagnosis, pharmaco- and psychotherapy].

Controlled studies and meta-analyses show not only that depression and cardiovascular disease often occur together, but that depressive illnesses are an independent risk factor in the development and the progression of coronary heart disease. It can be difficult to distinguish between reactive mood disturbance after myocardial infarction and depressive episodes that may have preceded the infarction and which require treatment. Due to this difficulty, depressive disorders are rarely diagnosed, and only a minority of patients receive adequate treatment. However, owing to the introduction of new antidepressants in recent years, the number of treatment options has increased. Specifically, selective serotonin reuptake inhibitors (SSRI) offer a valuable alternative to tricyclic antidepressants, which are problematic in heart disease. The authors describe on the one hand controlled studies of SSRIs and discuss differential therapeutic consequences. On the other hand, studies of psychotherapeutic interventions in comorbid patients with depression and coronary heart disease are reported. Finally, the authors discuss which psychotherapeutic interventions may be suitable.

Antidepressive Agents↗
PubMed2002

Review article: rabeprazole-based therapy in Helicobacter pylori eradication.

Rabeprazole's favourable pharmacodynamic profile is a result of its rapid onset and its 24-h control of gastric parietal secretion. These qualities, and its antimicrobial properties, make it particularly effective in the treatment of Helicobacter pylori (H. pylori), which is a short course of treatment compared to other conditions treated with proton pump inhibitors. Recently completed trials in combination with amoxicillin, clarithromycin and metronidazole for 7 days achieved high eradication of H. pylori. An additional study assessing the efficacy of combined rabeprazole and antibiotic treatments of 3, 7, and 10 days' duration vs. FDA-approved 10-day omeprazole triple therapy is under way to address the possibility of shorter duration therapies in the USA.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2001

In vitro correlate of immunity in a rabbit model of inhalational anthrax.

A serological correlate of vaccine-induced immunity was identified in the rabbit model of inhalational anthrax. Animals were inoculated intramuscularly at 0 and 4 weeks with varying doses of Anthrax Vaccine Adsorbed (AVA) ranging from a human dose to a 1:256 dilution in phosphate-buffered saline (PBS). At 6 and 10 weeks, both the quantitative anti-protective antigen (PA) IgG ELISA and the toxin-neutralizing antibody (TNA) assays were used to measure antibody levels to PA. Rabbits were aerosol-challenged at 10 weeks with a lethal dose (84-133 LD(50)) of Bacillus anthracis spores. All the rabbits that received the undiluted and 1:4 dilution of vaccine survived, whereas those receiving the higher dilutions of vaccine (1:16, 1:64 and 1:256) had deaths in their groups. Results showed that antibody levels to PA at both 6 and 10 weeks were significant (P<0.0001) predictors of survival.

Administration, Inhalation↗
PubMed2001

Efficacy of rabeprazole once daily for acid-related disorders.

Proton-pump inhibitors (PPIs) have revolutionized the treatment of gastroesophageal reflux disease (GERD) and peptic ulcer. To evaluate the efficacy of the new PPI rabeprazole, 12 controlled clinical trials were conducted worldwide-three for each indication (erosive or ulcerative GERD healing, long-term GERD healing maintenance, duodenal ulcer healing, and gastric ulcer healing). Rabeprazole was compared to placebo, the H2-receptor antagonist ranitidine, and the PPI omeprazole. Treatment duration ranged from < or =4 weeks for duodenal ulcer to < or =6 weeks for gastric ulcer, < or =8 weeks for GERD healing, and 1 year for maintenance of GERD healing. Rabeprazole was as effective as omeprazole for each indication and significantly more effective than ranitidine for healing of GERD (87% vs 66%) and duodenal ulcer (83% vs 73%). Rabeprazole was also superior to ranitidine in providing symptom relief, particularly in GERD.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2001

Pharmacokinetics and pharmacodynamics of dexamethasone sodium-m-sulfobenzoate (DS) after intravenous and intramuscular administration: a comparison with dexamethasone phosphate (DP).

The pharmacokinetics (PK) and pharmacodynamics (effects on blood lymphocytes) of dexamethasone (D) after intravenous (i.v.) administration of dexamethasone phosphate (DP, 10 mg, equivalent to 8.3 mg of dexamethasone) and after intravenous and intramuscular (i.m.) administration of dexamethasone sulfobenzoate sodium (DS, 9.15 mg, equivalent to 6 mg of dexamethasone) were assessed. Only 25% of DS was converted into dexamethasone with a half-life for DS of 5.4 hours and 7.4 hours after i.v. and i.m. administration, respectively. Consequently, the mean residence time of D after both i.m. and i.v. administration of DS (10.4-11.6 h) was longer than that after DP administration (6.1 h). The smaller lymphocyte suppression induced by DS (50% of that after DP administration) was shown to be related to differences in the pharmacokinetics. This study revealed significant differences in the pharmacokinetics of D after administration of DS and DP and stresses the importance of the prodrug for the pharmacological response. Because of the slow and incomplete conversion of DS into dexamethasone, its use in emergency medicine situations should be critically evaluated.

Adult↗
PubMed2001

Pharmacokinetics and rectal bioavailability of hydrocortisone acetate after single and multiple administration in healthy subjects and patients.

The pharmacokinetics and bioavailability of hydrocortisone after rectal administration of a hydrocortisone acetate foam were determined after single and multiple dosing in healthy subjects as well as in patients with inflammatory bowel disease. Endogenous hydrocortisone was suppressed by dexamethasone administration. Plasma levels were compared with those observed after intravenous administration of hydrocortisone. Only a very small part of the rectal dose (100 mg) was absorbed; the mean absolute bioavailability was 3.1% in healthy volunteers and 4.5% in patients. There was substantial intersubject variability. Although maximum hydrocortisone levels after single or multiple doses were significantly higher (about 70%) in the patient group, the systemic bioavailability is very low so that the risk of systemic side effects after rectal administration of hydrocortisone acetate foam has to be considered very low.

Administration, Rectal↗