Characterization of rat small intestinal and colon precision-cut slices as an in vitro system for drug metabolism and induction studies.

The aim of this study was to characterize rat small intestinal and colon tissue slices as a tool to study intestinal metabolism and to investigate gradients of drug metabolism along the intestinal tract as well as drug-induced inhibition and induction of biotransformation. Tissue morphology and the intestinal mucus layer remained intact in small intestinal and colon slices during 3 h of incubation, while alkaline phosphatase was retained and the rate of metabolism of three model compounds (7-hydroxycoumarin, 7-ethoxycoumarin, and testosterone) appeared constant. Phase I and phase II metabolic gradients, decreasing from stomach toward colon were shown to be clearly different for the model compounds used. Furthermore, the observed slice activities were similar or even higher compared with the literature data concerning metabolism of in vitro intestinal systems. Preincubation with beta-naphthoflavone for 24 h induced the O-deethylation of 7-ethoxycoumarin from nearly undetectable to 140 pmol/min/mg protein in small intestine (fresh slices, 43 pmol/min/mg protein) and to 100 pmol/min/mg protein in colon slices (fresh slices, undetectable). Ketoconazole inhibited metabolism of testosterone by 40% and that of 7-ethoxycoumarin by 100%. In conclusion, we showed that the intestinal slice model is an excellent model to study drug metabolism in the intestine in vitro, since we found that the viability parameters remain constant and the measured enzyme activities are relevant, sensitive to inhibitors, and inducible. Therefore, it is a promising tool to study intestinal drug metabolism in human intestine in vitro in the future.     

Komplikationen nach Hochdosistherapie und autologer Stammzelltransplantation Retrospektive Untersuchung an einem nicht selektionierten Patientenkollektiv

Zusammenfassung Hintergrund: Die Hochdosistherapie (HDT) mit autologer Stammzelltransplantation (ASZT) ist bei verschiedenen hämatologischen Tumoren zur Therapie der Wahl geworden. Obwohl die Neutropenie nach HDT nur kurz dauert, können lebensgefährliche Komplikationen auftreten. Bislang wurden nur wenige Arbeiten über die Komplikationen einer HDT mit ASZT bei unselektierten Patienten publiziert. Patienten und Methoden: Von 6/96 bis 12/99 wurden bei 42 Patienten 54 Transplantationen (neun Doppeltransplantationen, eine Dreifachtransplantation) durchgeführt. Der Altersmedian lag bei 55 Jahren (Spanne 25-74 Jahre). Das Geschlechtsverhältnis war ausgeglichen. 30 Patienten hatten hämatologische Neoplasien, zwölf waren an einem soliden Tumor erkrankt. Ergebnisse: Infektionen führten am häufigsten zu Komplikationen, danach folgte die Toxizität durch Mukosisis, Schmerzen oder Diarrhö. Bei vier Patienten fand sich eine positive Zytomegalie-Polymerase-Kettenreaktion (CMV-PCR). Zwei Patienten hatten Symptome entsprechend einer CMV-Erkrankung. Ein Patient erlitt eine busulfanbedingte Lungenfibrose und eine Lebervenenverschlusskrankheit. Zwei Patienten (4%) starben bei 54 Transplantationen an einer CMV-Pneumonie bzw. einem Multiorganversagen nach idiopathischer Pneumonie. Vier Patienten starben an einem Zweittumor (myelodysplastisches Syndrom zwei, solider Tumor zwei), wobei drei Patienten intensiv vorbehandelt waren. Wir untersuchten, ob die folgenden Faktoren die Komplikationsrate beeinflussten: Tumordiagnose (solide vs. hämatologisch), Anzahl der Vortherapien (< 2 vs. S: 2), Anzahl der CD34-positiven (CD34⁺) Zellen (< Median vs. S Median), Alter (⣗ Jahre vs. > 55 Jahre), Mukositis (WHO-Grad-1-2 vs. 3-4) und Transplantationsregime (myeloablativ vs. myelosuppressiv). Die Infektionsrate war bei Patienten mit myeloablativen Therapien höher als bei myelosuppressiv Behandelten, der Anstieg der Thrombozytenzahlen (15 vs. 9 Tage) langsamer. Eine höhere Anzahl CD34⁺ Zellen führte zu einem schnelleren Thrombozytentake (9 vs. 12 Tage). Bei Patienten mit mehr als einer Vortherapie traten mehr Infektionen auf (100% vs. 70%). Eine ausgeprägte Mukositis (WHO-Grad 3-4) führte sowohl zu einem langsameren Thrombozytenanstieg als auch zu mehr Infektionen. Keinen Einfluss auf die Komplikationen hatten die Tumordiagnose und das Alter. Schlussfolgerung: Die Komplikationsrate und die Mortalität unterschieden sich in dieser heterogenen Gruppe nicht von den Daten bei selektierten Patienten, bei denen ein definiertes Hochdosisprotokoll und eine bestimmte Tumorentität untersucht wurden. Die Komplikationsrate wird durch die Anzahl der Vortherapien, die Konditionierungstherapie und die Anzahl der transplantierten CD34⁺ Zellen beeinflusst. Abstract Background: High-dose therapy (HDT) with autologous blood stem cell transplantation (AST) has become the therapy of choice for patients with specific hematologic neoplasms. Although pancytopenia after HDT with stem cell support is of relatively short duration, complications may be severe and life-threatening. In unselected patients with hematologic and solid tummor malignancies, only few data have been published regarding complications. We therefore analyzed the rate of infection and toxicity in patients with different neoplasms undergoing HDT and ASCT. Patients and Methods: From 6/96 to 12/99 42 patients received 54 HDT and ASCT (nine tandem transplants and one triple transplant). The median age was 55 years (range 25-74 years) with equal sex distribution. 30 patients sufered from hematologic malignancies and twelve from solid tumors. Results: Infections were the major cause for complications followed by mucositis, pain and diarrhea. In four patients a positive cytomegalovirus polymerase chain reaction (CMV-PCR) was detected. In two patients this positive test result was accompanied by clinical symptoms of CMV infection. One patient developed lung fibrosis due to busulfan (WHO 4°) and additionally a veno-occlusive disease (VOD) of the liver (WHO 4°). Two patients (4%) died due to CMV pneumonia and multiple organ failure after idiopathic pneumonia, respectively. Four patients developed secondary neoplasms (two patients myelodysplastic syndromes, two patients solid tumors). Three of them had been heavily pretreated. We further analyzed whether the following parameters had an influence on the rate of complications: tumor diagnosis (hematologic vs. solid), number of pretreatment protocols (< 2 vs. S 2), CD34⁺ cell count (< median CD34⁺ cell count vs. S median CD34⁺ cell count), age (⣗ years vs. > 55 years), mucositis (WHO 1-2° vs. 3-4°) and conditioning regimen (myeloablative vs. myelosuppressive). The infection rate was higher in patients receiving myeloablative therapy compared to patients with myelosuppressive conditioning and the platelet count recovery was slower. In patients receiving a higher CD34⁺ cell count, time until platelets reached > 50/nl was shorter than in patients with a lower CD34⁺ cell count. Patients with S 2 pretreatment protocols had a higher infection rate than patients with < 2 pretreatments. Patients suffering from severe mucositis (WHO 3-4°) exhibited a slower platelet recovery and a higher infection rate. No difference was noted in the complication rate for the other parameters (tumor diagnosis, age). Conclusion: Complication rate and mortality in this heterogeneous patient group were not different from the data of other authors describing selected patients receiving a uniform conditioning regimen or having a distinct disease. The complication rate is influenced by the number of pretreatment protocols, conditioning regimens and the number of transplanted CD34⁺ cells.     

IgM Monoclonal Gammopathy of Undetermined Significance and Smoldering Waldenström's Macroglobulinemia

Immunoglobulin M monoclonal gammopathy of undetermined significance (IgM-MUS) was diagnosed in 213 Mayo Clinic patients who were residents of 11 counties in southeastern Minnesota from 1960 to 1994. During long-term follow-up, 29 (14%) developed non-Hodgkin lymphoma (n = 17), Waldenström's macroglobulinemia (WM; n = 6), chronic lymphocytic leukemia (n = 3), and AL amyloidosis (n = 3) with relative risks of 15-, 262-, 6-, and 16-fold, respectively. The cumulative probability of progression to one of these disorders was 10% at 5 years, 18% at 10 years, and 24% at 15 years, approximately 1.5% per year. Smoldering WM was identified in 48 patients at Mayo Clinic from 1974 to 1995. During follow-up, 33 of the 48 patients progressed to symptomatic WM. The median time to progression was 4.6 years. The risk of progression to WM was 6% at 1 year, 39% at 3 years, and 55% at 5 years.     

The perception of work stressors is related to reduced parasympathetic activity

Purpose  

The aim was to examine the perception of work stressors in relation to ambulatory measures of heart rate variability (HRV).     

Granddaughter's somersault treats cupulolithiasis of the horizontal semicircular canal

We report on a 61-year-old woman with cupulolithiasis of the right horizontal semicircular canal, which is usually difficult to treat. The patient reported that several years ago, similar symptoms relieved completely after having performed several somersaults together with her granddaughter. This time, repetitive somersaults were again effective to treat her benign paroxysmal positional vertigo. Acceleration during a somersault may induce an intracanalicular force strong enough to detach otoconia debris from the cupula. Rolling may then promote their reentrance into the utricle. This case suggests that repetitive somersaults may be an alternative treatment of cupulolithiasis of the horizontal semicircular canal.     

Comparison of T-cell receptor repertoire restriction in blood and tumor tissue of colorectal cancer patients

Several immunotherapeutic approaches rely on antigen-specific T-cells. Restrictions in the T-cell receptor (TCR) repertoire were reported as indicator of anti-tumor cytotoxic T-lymphocyte (CTL) response in various tumor entities. It is unclear yet whether a TCR restriction in peripheral blood mirrors the tumor compartment. We compared the expression of TCR Vβ-families for the quantification of TCR repertoire alterations in blood and tissue samples from patients with colorectal carcinoma. Blood samples from patients with colorectal carcinoma and healthy volunteers and tissue samples of normal colonic mucosa and colorectal carcinoma were analyzed. Relative Vβ-family quantification was performed based on quantitative reverse transcribed PCR. Standard deviation and average mean of the single families were determined. Two variables describing the degree of Vβ-repertoire restriction were defined. Forty-eight blood samples and 37 tissue samples were analyzed. TCR repertoire restriction was higher in blood of tumor patients than in blood of healthy controls (p < 0.05). No difference in the degree of TCR repertoire restriction was found between carcinoma and unaffected colon tissue. We found no corresponding elevated TCR families among the different compartments blood, normal colon, and carcinoma tissue of the same patient. In conclusion, we observed a repertoire restriction in peripheral blood as well as in tumor tissue of cancer patients. However, in tumor tissue, repertoire alterations were comparable to normal mucosa, suggesting compartment-specific TCR distribution rather than alterations due to tumor-T-cell interaction questioning the presence of highly restricted clonal T-cell expansions in colorectal cancer as they have been described in other, assumingly more immunogenic tumor entities.