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Biomedical subjects

R Straub

Publications and source records attributed to R Straub.

At least 55 records · Page 3Linked to original sources
PubMed2001

Comparison of the clearance of 99mTechnetium-DTPA from the lung and lung function indices derived from the single breath diagram for carbon dioxide in horses with chronic obstructive pulmonary disease.

The elimination of carbon dioxide from the lung can be used to monitor ventilation and perfusion, and 99mtechnetium-diethylenetriaminepentaacetate (99mTc-DTPA) clearance is a highly sensitive index of alveolar epithelial integrity, which is a presupposition for effective gas exchange. The aim of this study was to determine whether a correlation exists between indices of lung function derived from the single breath diagram for CO2, and 99mTc-DTPA clearance in horses with chronic obstructive pulmonary disease. The rate of 99mTc-DTPA elimination was negatively and substantially correlated with the dead space according to Bohr's formula, and the physiological and alveolar dead space. Strong and significant correlations existed between the three dead space indices and the alveolar fraction of CO2, and the ratio A1/A2 as an index of alveolar efficiency. The associations found were dependent on the clinical status of health and the mode of calculation of 99mTc-DTPA alveolar clearance.

Animals↗
PubMed2001

[Percutaneous laser ablation of malignant liver tumors].

PURPOSE: To present the technical data, methods and results of percutaneous laser ablation of malignant tumors. PATIENTS AND METHODS: In the period from June 1993 to April 2000 a collective of 600 patients with malignant liver tumors and liver metastases from different primary tumors were treated via MR-guided LITT. After sonographically or CT-guided puncture MR-compatible laser catheters were positioned. The tumor destruction was visualized via MR-thermometry. The checkup and the therapy accomplishment ensued in the course of an ambulant therapy concept. RESULTS: In the course of a local accomplished LITT of liver metastases and malignant liver tumors a local tumor control rate of 97.8 % was achieved. The complication rate was extremely low with a value of 2.2 % (1 441 treatments). The lethality rate was 0.1 %. The mean survival time referring to the whole patient collective was 47.7 months, in the case of liver metastases from a colorectal cancer a value of 46.8 months was achieved. CONCLUSION: MR-guided LITT is a local effective therapy with low morbidity in malignant liver tumors with a maximum quantity of 5 and a size of </= 5 cm.

Adult↗
PubMed2001

[Renal enhancement and excretion of the hepatobiliary contrast agent Gd-EOB-DTPA].

PURPOSE: To evaluate the clinical value of the renal clearance using MR imaging with different doses of gadolinium ethoxybenzyl-DTPA (Gd-EOB-DTPA) in comparison to gadolinium DTPA (Gd-DTPA). MATERIAL AND METHODS: In a double-blind and randomized clinical phase II study. MR imaging at 1.5 T was performed in 61 patients with five different doses of Gd-EOB-DTPA (3, 6, 12.5, 25 and 50 micromol/kg b. w. as a bolus injection). The study protocol comprised T(1)- and T(2)-weighted spin-echo magnetic resonance and two-dimensional fast low-angle shot imaging before and at increasing intervals for up to 45 min after injection of Gd-EOB-DTPA. These images were compared with Gd-DTPA-enhanced imaging (0.1 mmol/kg b. w. as a bolus injection). RESULTS: After bolus injection of the hepatobiliary MR contrast agent Gd-EOB-DTPA a renal elimination was observed. Immediately after the injection of Gd-EOB-DTPA until the eighth minute a corticomedullary enhancement of the kidney was conspicuous. After the fourth minute a contrast enhancement could be seen in the renal pelvis. The best enhancement was noted after 20 minutes in the FLASH GRE and T(1)-weighted images with good pelvicaliceal contrast. After 45 minutes an outflow of Gd-EOB-DTPA into the ureter could be observed. CONCLUSION: In addition to the hepatobiliary secretion Gd-EOB-DTPA appears useful for the evaluation of renal structures and renal function on account of the renal excretion without diuretic preparation of the patients.

Adult↗
PubMed2001

Quality programmes, accreditation and certification in Switzerland.

PURPOSE: To report on current quality initiatives in health care in the context of accreditation and certification in Switzerland. SOURCE OF INFORMATION: A review from the Swiss Accreditation Service, the Swiss Medical Association and the University of Zurich. SETTING: In Switzerland, health care providers and health insurers are obliged by law to sign contracts on quality of care. The law texts and related ordinances do not state explicitly the content and format of quality contracts between providers and costs payers. Finding adequate practical solutions is the responsibility of the partners involved. Six different possibilities of quality initiatives are studied and discussed in this report. These include initiatives to create independent certification or inspection bodies for health care organizations accredited by the national accreditation body. FINDINGS: So far, there is only one established standardized system with clear requirements. This accreditation and certification model is an adaptation of the International Standards Organization but so far it has not been used often in the public domain. Each of the other five approaches are more frequently applied but none of them lead to full external peer review certification including medical outcome yet. CONCLUSIONS: A lot of harmonization work still has to be done and clear branch specific requirements need to be agreed upon. Practicability and validity of external peer review schemes may also need further evaluation and improvement to reach the goals of health care systems in the future.

Accreditation↗
PubMed2000

[Cystic fibrosis--initial diagnosis in a 39-year-old patient].

BACKGROUND: Cystic fibrosis is the most common hereditary disorder among Caucasians. Most of the patients are diagnosed as children. However, some cases are going undiagnosed into adulthood and are then often misdiagnosed because the non-pediatricians do not know cystic fibrosis very well and do not consider this diagnosis in adult patients. CASE REPORT: We present the medical history of a woman, who was diagnosed with cystic fibrosis at the age of 39 years, although she had suffered from bronchiectasis, pancreatic insufficiency and liver cirrhosis since many years. Her medical history was long with some diagnosis, but because of her age nobody considered the final diagnosis. CONCLUSION: In adult patients with bronchiectasis, liver cirrhosis and pancreatic insufficiency in combination or with only one of these symptoms, cystic fibrosis should be included into the differential diagnosis.

Adult↗
PubMed2000

Allergen-specific IgE levels against crude mould and storage mite extracts and recombinant mould allergens in sera from horses affected with chronic bronchitis.

Immunoglobulin E antibody (IgE) levels against four recombinant (r) mould allergens (r-Aspergillus fumigatus [rAsp f] 7, 8 and 9; r-Alternaria alternata 1 [rAlta1]) and crude mould (Aspergillus fumigatus, Alternaria alternata, Penicillium notatum) and storage mite extracts were determined by ELISA in sera from 24 pulmonary sound control horses and 26 horses suffering from chronic bronchitis/bronchiolitis (CB), also called chronic obstructive pulmonary disease (COPD). Serum IgG and IgA titres were also determined against Aspergillus fumigatus extract and rAsp f 8.IgE against the crude extracts could be measured in all sera, but there was no significant difference between CB-affected and control horses. In contrast, only 8-30% of the horses, depending on the r-allergen tested, had detectable IgE levels in serum against the r-allergens. Horses with CB had significantly more often detectable IgE levels than controls against rAlt a 1 (10/26 and 3/24, respectively, p=0. 054), rAsp f 7 (13/26 and 2/24, respectively, p<0.01) and rAsp f 8 (11/26 and 1/24, respectively, p<0.01). Only four horses (three CB-affected and one healthy, p0.05) had detectable IgE levels against rAsp f 9. Furthermore, CB-affected horses were often sensitised against two or more r-allergens (13/26 of the CB-affected horses) while only one of the 24 healthy horses had positive IgE levels against more than one r-allergens. Similarly to IgE levels, no significant differences between CB-affected and healthy horses were found for IgG titres against the Aspergillus fumigatus extract. However, horses with CB had significantly higher serum IgG titres against rAsp f 8 than healthy controls (median=28 versus 10 relative ELISA units [REU], p<0.01). Additionally, horses with detectable IgE titres against rAsp f 8 had significantly higher IgG titres against this r-allergen than horses with undetectable IgE titres (median IgG titres=46 and 13 REU, respectively; p<0.01). For serum IgA titres, neither differences between healthy and CB-affected animals nor correlations between IgA and IgG or IgE titres could be found. These results show that horses suffering from CB are more often sensitised to some Aspergillus fumigatus and Alternaria alternata allergens than control horses and that they are partly sensitised to the same fungal proteins as mould-allergic human patients. Furthermore, this study shows that r-allergens allow a much more sensitive determination of specific serum antibody levels by ELISA than crude mould extracts.

Allergens↗
PubMed2000

Detection of the ADP-ribosyltransferase toxin gene (cdtA) and its activity in Clostridium difficile isolates from Equidae.

Clostridium difficile is an antibiotic-associated emerging pathogen of humans and animals. Thus far three toxins of C. difficile have been described: an enterotoxin (ToxA), a cytotoxin (ToxB) and an ADP-ribosyltransferase (CDT). In the present work we describe the first isolation of CDT producing C. difficile from Equidae with gastro-intestinal disease. Out of 17 C. difficile strains isolated from Equidae, 11 were positive for the genes tcdA and tcdB encoding ToxA and ToxB. In addition four of these 11 isolates were positive for the cdtA gene encoding the catalytic subunit of the ADP-ribosyltransferase CDT. Interestingly none of the isolates derived from canines (41 isolates) and felines (4 isolates) harboured the cdtA gene. In C. difficile field isolates which contained the cdtA gene, ADP-ribosyltransferase activity could also be detected in culture supernatants indicating expression and secretion of CDT. All strains were associated with intestinal disorders, but no association was found for the occurrence of toxins with a specific clinical diagnosis.

ADP Ribose Transferases↗
PubMed2000

[Percutaneous interstitial thermotherapy of malignant liver tumors].

PURPOSE: Description of local ablative techniques such as laser-induced thermotherapy (LITT) and radiofrequency ablation in the percutaneous interstitial thermotherapy for malignant liver tumors. PATIENTS AND METHODS: MR-guided LITT is currently performed by means of implantable percutaneous catheter systems. CT is used to control the insertion of the catheter. Irrigated administration systems are available both for LITT and for radiofrequency therapy. RESULTS: At present LITT enables a local tumor control of 97.2% for localized liver metastases without extrahepatic spreading patterns. In a group of 381 patients the average survival times were 45.7 months for patients with liver metastasis, 42.7 months for those with colorectal liver metastases, and 32 months for HCC tumors. The data for radiofrequency ablation confirm the high value for tumor control of hepatocellular carcinomas with poorer results for liver metastases. CONCLUSIONS: Percutaneous, MR-guided LITT permits good tumor control of liver metastases smaller than 5 cm and less than 5 in number. For HCC, at present percutaneous injection of alcohol, radiofrequency ablation, and LITT are equally effective.

Breast Neoplasms↗
PubMed2000

[Multi-sequential arterial chemoembolization of advanced hepatocellular carcinomas: computerized tomography follow-up parameters for evaluating effectiveness of therapy].

PURPOSE: An evaluation of clinical and computed tomography parameters for the transarterial chemoembolization (TACE) of hepatocellular carcinoma (HCC). MATERIAL AND METHODS: Retro- and prospective analysis of 123 TACE procedures in 37 patients (mean age: 63.3 years). RESULTS: Overall mean survival rate for all treated patients was 785 days with a mean value of 387 days. The 1 year survival rate was 62%. Quantitative tumor volumetry revealed a significant difference in survival rate with a mean value of 678 days for patients with a reduction of tumor volume between 0 and 50%, 976 days for a volume reduction of 51-100% and 277 days for an increase in tumor volume during therapy. Patients with a high lipiodol retention presented improved survival data (902 days) versus patients with a low lipiodol retention (513 days). Homogeneous retention of lipiodol was a positive factor on survival as compared to an inhomogenous form of retention. CONCLUSION: In patients with a positive therapy response after TACE the prognosis can be improved by repeated embolization.

Aged↗
PubMed2000

[CT-guided percutaneous intratumoral chemotherapy with a novel cisplatin/epinephrine injectable gel for the treatment of inoperable malignant liver tumors].

PURPOSE: To evaluate prospectively the volumetric changes of tumor and necrosis in unresectable malignant liver tumors and the clinical aspects after CT-guided direct intratumoral administration of a novel cisplatin/epinephrine injectable gel in a clinical phase II study. PATIENTS AND METHODS: 8 patients with 17 colorectal liver metastases with a mean volume of 42 ml were treated with a mean of 5.1 injections and 8 patients with 11 HCC nodules (mean volume of 22.1 ml) with a mean of 3.25 treatments with CT-guided local administration of a novel cisplatin/epinephrine gel. This method of administration provides a higher local and lower systemic drug concentration. Volumes of tumor and necrosis prior to and after treatment were measured by computer-generated volumetric analysis. RESULTS: Contrast-enhanced studies verified pretherapeutic tumor necrosis with a value of 12.6% in the metastases and 0.6% in the HCC nodules. Intratumoral drug administration resulted in a necrotic volume of 110% in metastases and 128% in HCC versus the mean initial tumor volume, at least 4 treatments resulted in 122% necrosis in metastases and 130% in HCC. Local therapy control rate for the follow-up to 6 months was 38% and 83.3% for the group of metastases and HCC, respectively. CONCLUSIONS: Direct intratumoral injection of a novel cisplatin/epinephrine injectable gel results in an induction of a relevant necrosis in malignant liver tumors, with a substantially higher local therapy control rate for HCC compared to colorectal metastases.

Adult↗
PubMed2000

Comparative in vivo activity of gemifloxacin in a rat model of respiratory tract infection.

The in vivo efficacy of the novel quinolone gemifloxacin (SB-265805) was examined in a rat respiratory tract infection (RTI) model against four strains of Streptococcus pneumoniae and two strains of Haemophilus influenzae with varying susceptibilities to standard antimicrobial agents. Animals were infected intrabronchially to produce pneumonia and therapy with oral gemifloxacin, amoxycillin-clavulanate, ciprofloxacin, cefuroxime, azithromycin, trovafloxacin, grepafloxacin or levofloxacin was started 24 h after infection. The doses administered were chosen to approximate in the rat the serum or tissue concentrations measured in humans following therapeutic dosing. Therapy continued once- or twice-daily for 3 days, and approximately 17 h after the end of therapy the lungs were excised for bacterial enumeration. Following infection with strains of S. pneumoniae, gemifloxacin produced a 3-5 log reduction in bacterial numbers compared with untreated animals. Gemifloxacin was as effective as amoxycillin- clavulanate, and was as potent or more potent than all other comparators. Notably, the quinolone agents trovafloxacin, ciprofloxacin, grepafloxacin and levofloxacin were significantly less effective (P < 0.01) than gemifloxacin: these agents reduced bacterial numbers by < or =3 log compared with untreated animals. Gemifloxacin produced a marked response against H. influenzae infection, reducing bacterial numbers significantly (P < 0.01) compared with untreated controls. Gemifloxacin was significantly more potent than cefuroxime and azithromycin. None of the other comparator agents was more potent than gemifloxacin. The excellent efficacy seen in these experimental models of RTI with S. pneumoniae and H. influenzae confirms the in vitro activity of gemifloxacin against these organisms. This indicates that gemifloxacin may be of significant benefit in the treatment of RTI.

Animals↗
PubMed2000

Comparative efficacy of gemifloxacin in experimental models of pyelonephritis and wound infection.

Gemifloxacin (SB-265805) is a potent, novel fluoroquinolone with broad-spectrum antimicrobial activity. In this study, the efficacy of gemifloxacin was studied in experimental models of Gram-negative pyelonephritis (caused by Escherichia coli or Proteus mirabilis) and Gram-positive wound infection resulting from Streptococcus pyogenes, Staphylococcus epidermidis or Staphylococcus aureus. Gemifloxacin activity against these pathogens was compared with those of amoxycillin-clavulanate, ciprofloxacin, cefuroxime, azithromycin, trovafloxacin, grepafloxacin, levofloxacin and tosufloxacin. Oral treatment was initiated 1 h after infection and continued once or twice daily for 3 days. Around 17 h after the end of treatment, animals were killed and the infected kidneys or the skin around the wound site were excised for the enumeration of viable bacteria. In the pyelonephritis model (either microorganism), gemifloxacin reduced bacterial numbers significantly (P < 0.01) compared with no treatment. No comparator agent had a greater effect than gemifloxacin. Notably, grepafloxacin and azithromycin were significantly less effective (P < 0.01) than gemifloxacin against E. coli pyelonephritis, and amoxycillin-clavulanate, azithromycin and trovafloxacin were inferior (P < 0.01) against P. mirabilis infection. In the S. pyogenes wound infection model, gemifloxacin, amoxycillin-clavulanate, cefuroxime and azithromycin reduced bacterial numbers significantly compared with controls (P < 0.01). Results for the comparator quinolones were not significantly different from untreated controls (P > 0.05). Gemifloxacin was also effective against staphylococcal infection, as were grepafloxacin and levofloxacin, while ciprofloxacin, trovafloxacin and tosufloxacin were significantly less effective against these pathogens than gemifloxacin (P < 0.01). No comparator agent had greater activity than gemifloxacin against S. pyogenes or S. aureus infections. These data demonstrate the potential benefit of gemifloxacin in the treatment of Gram-negative urinary tract infection and Gram-positive skin and soft tissue infection.

Animals↗
PubMed1999

[Therapeutic options in non-resectable liver metastases. Percutaneous radiological interventions].

In patients with irresectable liver metastases the following spectrum of oncological concepts is in use. Percutaneous interventional methods allows for an optimized local control rate in strictly intrahepatic disease. Regional short-term time chemotherapy and transarterial chemoembolization (TACE) belong to regional methods. As local ablative methods, intratumoral drug application, endotumoral chemotherapy and alcohol instillation can be used. The most promising thermotherapeutic strategies are radiofrequency and laser-induced thermotherapy (LITT). In a prospective study 278 patients suffering from liver metastases were treated with MR-guided LITT and exact data for the local control rate and survival rate were evaluated. The overall cumulative survival rate (Kaplan-Meier) of patients with liver metastases was 40.8 months (median: 40.97 months, 95% confidence interval 36.3-45.2).

Adult↗
PubMed1999

[Interventional MR-guided laser induced thermotherapy in oncologic indications. Status and prospects].

MR-guided LITT (laser-induced thermotherapy) is currently being evaluated for its effectiveness in clinical oncology. MR-guided LITT is defined as a minimally invasive technology based on the effects of the applied Nd-YAG laser on tumorous tissue. Due to specific characteristics of the laser-induced coagulative effect, online monitoring via MR thermometry is possible and extremely precise. In a period of 6 years 335 patients suffering from malignant soft tissue tumors were prospectively treated via MR-guided LITT. We evaluated the local tumor control rate, the rate of complications and the survival data from the clinical and MRI follow-up. Our results prove that MR-guided LITT results in a extremely low rate of side effects and an effective tumor control rate higher than 95%, depending on the size of the lesion. It is concluded that this therapeutic concept is of clinical value for patients with primary and secondary liver cancer, malignant lymph node involvement, abdominal recurrent tumors and tumors of the head and neck.

Adult↗
PubMed1999

Liver metastases: interventional therapeutic techniques and results, state of the art.

The liver is the most common site of metastatic tumour deposits. Hepatic metastases are the major cause of morbidity and mortality in patients with gastrointestinal carcinomas and other malignant tumours. The rationale and results for interventional therapeutic techniques in the treatment of liver metastases are presented. For the treatment of patients with irresectable liver metastases, alternative local ablative therapeutic modalities have been developed. Technique and results of local interventional therapies are presented such as microwave-, radiofrequency (RF)- and ultrasound ablation, and laser-induced interstitial therapy (LITT), cryotherapy and local drug administration such as alcohol injection, endotumoral chemotherapy and regional chemoembolisation. In addition to cryotherapy, all ablative techniques can be performed percutaneously with low morbidity and mortality. Cryotherapy is an effective and precise technique for inducing tumour necrosis, but it is currently performed via laparotomy. Percutaneous local alcohol injection results in an inhomogeneous distribution in liver metastases with unreliable control rates. Local chemotherapeutic drug instillation and regional chemoembolisation produces relevant but non-reproducible lesions. Laser-induced interstitial thermotherapy (LITT) performed under MRI guidance results in precise and reproducible areas of induced necrosis with a local control of 94%, and with an improved survival rate. Interventional therapeutic techniques of liver metastases do result in a remarkable local tumour control rate with improved survival results.

Antineoplastic Agents↗
PubMed1999

Interventional MR: interstitial therapy.

The rationale and results for interstitial therapies via interventional MRI in the treatment of tumors in various regions are presented. Different interstitial treatment techniques are presented based on varying technologies both for tumor ablation and treatment monitoring. Data are presented based on 335 patients, 29-84 years of age (mean age 59 years, 196 men and 139 women) with a total of 932 liver tumors, 16 head and neck tumors and 14 abdominal recurrent pelvic and lymphatic tumors. All lesions had been treated with MR-guided laser-induced interstitial thermotherapy (LITT) via 2516 laser applications and 1856 cannulations. Data in the literature are extremely varying depending on author experience, treatment technique, and the included patient material. In our patient material we were able to achieve a local tumor control of 96.7% depending on the size of the tumorous lesion, the topographical relationship, and the applied laser parameters. The overall cumulative survival rate of patients with liver metastases was 45.74 months (median 40.97 months, 95 % confidence interval 31.42-50.52). The cumulative survival rate of the patient group with hepatic metastases of colorectal carcinoma was 42.71 months (median 39.33 months, 95% confidence interval 33.26-45.37). In patients with head and neck tumors a relevant reduction in clinically relevant symptoms such as pain, swallowing disorders, or nervous compression was achieved in 11 of 15 patients treated with LITT. In 14 soft tissue tumors, such as pelvic tumor recurrence and lymph node metastases, a local tumor control was obtained in 68% of lesions. Interstitial therapies under interventional MRI guidance, such as LITT, results in a high local tumor control with an improved survival rate.

Abdominal Neoplasms↗
PubMed1999

Phenotypic analysis of bronchoalveolar lavage fluid lymphocytes in horses with chronic pulmonary disease.

A panel of specific antibodies against CD3, CD4, CD5, CD8, MHC I and II was used in single and two colour flow cytometry to define T cell subpopulations in bronchoalveolar lavage fluid of horses affected with chronic obstructive pulmonary disease and of healthy controls. According to the results of the clinical examination including bronchoscopy and cytology of the tracheal aspirate the horses were divided into four groups (healthy, subclinically to mildly affected; moderately affected, and severely affected). All groups of horses had a similar percentage of CD3+ cells in the BALF. Compared to controls, severely affected horses had a significantly increased number of CD4+ cells in the BALF, but a similar percentage of CD4+ cells whereas mildly and moderately affected horses had a decreased percentage. The percentage and number of CD8+ cells and the percentage of CD8+/MHCII+ cells in the BALF was found to be higher than normal and varied according to the disease state. This novel finding raises the possibility that not only the CD4+ cells but also the CD8+ cells are involved in the pathogenesis of COPD. The percentage and the number of CD8+ cells in BALF might be of diagnostic value to detect subclinical to mild cases of COPD.

Animals↗