Positive correlation between aortic valve pressure gradient and mitochondrial respiratory chain capacity in hypertrophied human left ventricle

Summary The effect of chronic left ventricular pressure overload on the activities of mitochondrial respiratory chain enzymes was investigated in myocardial biopsies from the left ventricular apex of 13 patients undergoing aortic valve replacement for aortic valve stenosis. Transvalvular pressure gradients measured by left-sided heart catheterization ranged from 52 to 100 mmHg. The specific activity of mitochondrial respiratory chain enzyme complexes I + III (antimycin A sensitive NADH cytochrome c oxidoreductase) and the myocardial concentrations of coenzyme Q₁₀ (CoQ₁₀) increased significantly (P < 0.05) with increasing aortic valve pressure gradient. In contrast, the specific activities of complex IV (cytochrome c oxidase), succinate dehydrogenase, and citrate synthase, a mitochondrial matrix enzyme, showed no significant correlation with the pressure gradient. Since (CoQ₁₀) is the rate-limiting compound of the activity of complexes 1+111 but not of cytochrome c oxidase, succinate dehydrogenase, or citrate synthase, these data suggest that the increase in the activity of complexes I+III is due to the increase in (CoQ₁₀) content.Abbreviations CoQ coenzyme Q - CoQ₉ coenzyme Q₉ - CoQ₁₀ coenzyme Q₁₀ - SDH succinate dehydrogenase - NCP noncollagen protein     

Preparing monolayers of non-adherent mammalian cells

A simple method is described for preparing monolayers of non-adherent cells, using concanavalin A to bind the cells to wells of plastic microtest plates. The method was used successfully with all 202 human cell types tested, which included 23 tissue culture lines, 165 fresh specimens of all major histological types of leukemia and lymphoma, 20 fresh myelomas, 2 fresh thymomas, normal spleen and lymph node cells, fractionated T lymphocytes and B lymphocytes from peripheral blood, and cultured fetal amniotic cells. All cell types attached firmly, and were not detached by subsequent vigorous washing. In contrast, attempted attachment of cells in serum free medium, or with poly-L-lysine or glutaraldehyde, was ineffective with many cell types. We used the monolayers as target cells for antibodies to cell surface antigens, utilizing immune rosetting or complement-mediated cytotoxicity. This procedure should simplify most assays involving non-adherent target cells.     

Identification of high risk patients with severe, but asymptomatic aortic stenosis

Whether asymptomatic patients with severe aortic stenosis benefit from surgery remains unclear. We report our data recently published in the New England Journal of Medicine on the natural history of this disease and predictors of outcome.     

TRIO amplification and abundant mRNA expression is associated with invasive tumor growth and rapid tumor cell proliferation in urinary bladder cancer

Studies by comparative genome hybridization have suggested that 5p amplification is related to tumor progression in urinary bladder cancer. In this study seven genes (TAS2R, ADCY2, DNAH5, CTNND2, TRIO, ANKH, and MYO10) located to 5p15.31-5p15.1 were analyzed by fluorescence in situ hybridization using a tissue microarray containing samples from tumors and cell lines with known 5p amplification by comparative genome hybridization. Amplification frequency was highest for TRIO, which maps to 5p15.2 and encodes a protein with a putative role in cell-cycle regulation. To further investigate the role of TRIO amplification in bladder cancer, a tissue microarray containing samples from 2317 bladder tumors was used for fluorescence in situ hybridization analysis. TRIO amplification was strongly associated with invasive tumor phenotype, high tumor grade, and rapid tumor cell proliferation (Ki67 LI) (P < 0.0001 each). Only 7 of 456 pTaG1/G2 tumors (1.5%) but 62 of 485 pT1-4 carcinomas (12.8%) had TRIO amplification. TRIO amplification was not associated with poor prognosis. Using a frozen bladder tumor tissue microarray RNA in situ hybridization confirmed that TRIO is up-regulated in amplified tumors. It is concluded that TRIO up-regulation through amplification has a potential role in bladder cancer progression.     

The formation of B-lymphocyte colonies in agar contained in glass capillaries.

Optimal conditions were established for a micro method for the production of colonies of B lymphocytes from mouse spleen cells cultured in agar in glass capillaries, in the presence of bacterial lipopolysaccharide (LPS). Besides LPS the cultures require 5 X 10(-5) M mercaptoethanol and 20% horse serum for optimal colony growth. Foetal calf serum and heat-inactivated horse or foetal calf serum were found to be inferior. An agar gel strength of 0.3% was best for colony counting. A sigmoid curve was obtained when the number of colonies formed was related to the seeded cell density suggesting that some kind of cell to cell co-operation is essential for colony formation. The daily kinetics of colony growth were followed by microscopic colony counting and photometric capillary scanning with integration of the signal areas. Both methods indicated that colony growth had ceased by day 6. The combination of both methods gave the most realistic picture of B-lymphocyte colony development.     

Cytoprotection by somatostatin of normal and malignant clonogenic cells against the in vitro cytotoxicity of bischloroethylnitrosourea (BCNU)

The various pharmacological effects of somatostatin may be explained by the hypothesis that the paracrine peptide, by "stabilizing" cell membranes, inhibits the secretion of hormones as well as protects other cells (vascular endothelium, parenchyma) from different lesions (vasculo-, organo-, cytoprotection). This hypothesis was tested in vitro, using bischloroethyl-nitrosourea (BCNU)-intoxicated stem cells of normal mouse granulopoiesis and of the L 1210 leukemia. Clonogenic mouse bone marrow and L 1210 cells were grown in agar-containing glass capillaries. Using these colony assays and a ID90 of BCNU, cyclic somatostatin influenced the BCNU-cytotoxicity neither at simultaneous nor at subsequent application. However, when given 2 h prior to BCNU, the inhibition of colony growth was almost totally abolished. This cytoprotective effect was seen with normal granulopoietic as well as with leukemic cells. The effect did not show up, if the inactive linear somatostatin was used. N-acetyl-cysteine, a SH-compound applied as a chemoprotective adjunct, did not reveal a cytoprotective effect under identical experimental conditions, either. The results were discussed in view of common efforts to reduce the toxicity of cancer chemotherapy.     

A DROP-IN Gamma Probe for Robot-assisted Radioguided Surgery of Lymph Nodes During Radical Prostatectomy

BackgroundThe DROP-IN gamma probe was introduced to overcome the restricted manoeuvrability of traditional laparoscopic gamma probes. Through enhanced manoeuvrability and surgical autonomy, the DROP-IN promotes the implementation of radioguided surgery in the robotic setting.ObjectiveTo confirm the utility and safety profile of the DROP-IN gamma probe and to perform a comparison with the traditional laparoscopic gamma probe and fluorescence guidance.Design, setting, and participantsTwenty-five prostate cancer patients were scheduled for a robot-assisted sentinel lymph node (SN) procedure, extended pelvic lymph node dissection, and prostatectomy at a single European centre.Surgical procedureAfter intraprostatic injection of indocyanine green (ICG)-^99mTc-nanocolloid (n = 12) or ^99mTc-nanocolloid + ICG (n = 13), SN locations were defined using preoperative imaging. Surgical excision of SNs was performed under image guidance using the DROP-IN gamma probe, the traditional laparoscopic gamma probe, and fluorescence imaging.MeasurementsIntraoperative SN detection was assessed for the different modalities and related to anatomical locations. Patient follow-up was included (a median of 18 mo).Results and limitationsOverall, 47 SNs were pursued in vivo by the DROP-IN gamma probe, of which 100% were identified. No adverse events related to its use were observed. In vivo fluorescence imaging identified 91% of these SNs. The laparoscopic gamma probe identified only 76% of these SNs, where the detection inaccuracies appeared to be related to specific anatomical regions.ConclusionsOwing to improved manoeuvrability, the DROP-IN probe yielded improved SN detection rates compared with the traditional gamma probe and fluorescence imaging. These findings underline that the DROP-IN technology provides a valuable tool for radioguided surgery in the robotic setting.Patient summaryRadioguided robot-assisted surgery with the novel DROP-IN gamma probe is feasible and safe. It enables more efficient intraoperative identification of sentinel lymph nodes than can be achieved with a traditional laparoscopic gamma probe. The use of the DROP-IN probe in combination with fluorescence imaging allows for a complementary optical confirmation of node localisations.     

Nichtinvasive Beatmungs- und Lagerungstherapie bei COVID-19

Die Anaesthesiologie - Schwere Verläufe von COVID-19 führen bei Versagen einer unterstützenden nichtinvasiven Beatmung („high flow“, CPAP bzw. NIV) zur Eskalation der...     

Measuring physician practice site characteristics: A comparison of data from SK&A and a practice site survey

ObjectiveTo evaluate the comparability of commercially available practice site data from SK&A with survey data to understand the implications of using SK&A data for health services research.Data sourcesResponses to the Comprehensive Primary Care Plus (CPC+) Practice Survey and SK&A data.Study designComparison of CPC + Practice Survey responses to SK&A information for 2698 primary care practice sites.Data collectionCPC + Practice Survey data collected through a web‐only survey from April through September 2017, and SK&A data purchased in November 2016.Principal findingsInformation was similar across data sources, although some discrepancies were common. For example, 56% of practice sites had differences in the reported number of practitioners, and larger sites tended to have larger differences. Among practice sites with 1 practitioner in the survey, only 1.3% had a difference of 3 or more practitioners between the data sources, whereas 63% of practice sites with 11 or more practitioners had a difference of 3 or more practitioners.ConclusionsDiscrepancies between data sources could reflect differences of interpretation when defining practice site characteristics, changes over time in those characteristics, or data errors in either SK&A or the survey. Researchers using SK&A data should consider possible ramifications for their studies.