Use of robotized DNA isolation and real-time PCR to quantify and identify close correlation between levels of Neisseria meningitidis DNA and lipopolysaccharides in plasma and cerebrospinal fluid from patients with systemic meningococcal disease

The present study, using robotized DNA isolation and quantitative PCR based on the Neisseria meningitidis-specific capsular transport A gene, demonstrates the ease, rapidity, specificity, and sensitivity of quantifying neisserial DNA in plasma (n = 65) and cerebrospinal fluid (CSF) (n = 12) from patients with systemic meningococcal disease. We found a close correlation between the levels of neisserial DNA and lipopolysaccharides in plasma (r = 0.905) and in CSF (r = 0.964). The median concentration of neisserial DNA in plasma in 23 patients with persistent shock was 2 x 10(7) copies/ml, versus <10(3) copies/ml in 42 nonshock patients. Furthermore, quantitative PCR made possible estimates of the total number of meningococci in plasma, as opposed to conventional blood cultures, suggesting about 1,000 dead meningococci for every viable bacterium. Finally, with logistic regression analyses, neisserial DNA may predict a patient's disease severity and outcome at hospital admission. The number of meningococci in plasma and CSF appears to be the main determinant of the lipopolysaccharide levels, clinical presentation, and outcome.     

Increased brain natriuretic peptide and atrial natriuretic peptide plasma concentrations in dialysis-dependent chronic renal failure and in patients with elevated left ventricular filling pressure

Brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) plasma concentrations were measured in patients with dialysis-dependent chronic renal failure and in patients with coronary artery disease exhibiting normal or elevated left ventricular end-diastolic pressure (LVEDP) (n = 30 each). Blood samples were obtained from the arterial line of the arteriovenous shunt before, 2 h after the beginning of, and at the end of hemodialysis in patients with chronic renal failure. In patients with coronary artery disease arterial blood samples were collected during cardiac catheterization. BNP and ANP concentrations were determined by radioimmunoassay after Sep Pak C₁₈ extraction. BNP and ANP concentrations decreased significantly (P < 0.001) during hemodialysis (BNP: 192.1 ± 24.9, 178.6 ± 23.0, 167.2 ± 21.8 pg/ml; ANP: 240.2 ± 28.7, 166.7 ± 21.3, 133.0 ± 15.5 pg/ml). The decrease in BNP plasma concentrations, however, was less marked than that in ANP plasma levels (BNP 13.5 ± 1.8%, ANP 40.2 ± 3.5%; P < 0.001). Plasma BNP and ANP concentrations were 10.7 ± 1.0 and 60.3 ± 4. 0 pg/ml in patients with normal LVEDP and 31.7 ± 3.6 and 118.3 ± 9.4 pg/ml in patients with elevated LVEDP. These data demonstrate that BNP and ANP levels are strongly elevated in patients with dialysis-dependent chronic renal failure compared to patients with normal LVEDP (BNP 15.6-fold, ANP 2.2-fold, after hemodialysis; P < 0.001 or elevated LVEDP (BNP 6.1-fold, ANP 2.0-fold, before hemodialysis; P < 0.001), and that the elevation in BNP concentrations was more pronounced than that in ANP plasma concentrations. The present results provide support that other factors than volume overload, for example, decreased renal clearance, are also involved in the elevationin BNP and ANP plasma levels in chronic renal failure. The stronger elevation in BNP concentrations in patients with chronic renal failure and in patients with elevated LVEDP and the less pronounced decrease during hemodialysis suggest a different regulation of BNP and ANP plasma concentrations.[/ p]Abbreviations ANP atrial natriuretic peptide - BNP brain natriuretic peptide - LVEDP left ventricular end-diastolic pressure Correspondence to: C. Haug     

[3H] UK-14,304, a new agonist ligand of α2-adrenoceptors: a comparative study with human and rat tissue

Summary [³H] UK-14,304 was used to investigate ₂-adrenoceptors in rat brain and human platelets. Receptor pharmacology revealed that the ligand binds with high affinity to ₂-adrenoceptors. Psychoactive substances like neuroleptics, antidepressants, and-carbolines displace [³H] UK-14,304 from its binding sites in the lower micromolar range. A Hill number around 2 for most neuroleptics suggests a positive cooperativity with the ₂-adrenoceptors.Comparative studies with [³H] UK-14,304 and [³H] clonidine utilizing platelet membranes from human volunteers demonstrated that the former ligand is more suitable to investigate possible changes of ₂-adrenoceptors; [³H] UK-14,304 labels more receptors with a lower standard deviation, whereby the volume of the blood sample amounted to 35 ml instead of 50 ml required for [³H] clonidine as ligand. No sex differences of binding constants were detected, however an inverse correlation of maximum number of binding sites and affinity was found for female subjects with both ligands.No age-dependent changes of B_max and K_D-values were observed in the range of 24 to 59 years.     

History of neuromorphometry

The history of morphometry begins in the middle of the last century. At the turn of the century impulses had decreased. The alterations arising during the preparation of the tissues were almost unknown. For example, the dogma of the loss of neurons during aging was conditioned by age-dependent histological shringage of the brain. Beginning in the thirties of this century new thoughts have given impulses to new morphometric investigation. In the neurosciences important impulses came from Bok. In 1961 Elias introduced the term "stereology" as a new interdisciplinary science in order to communicate the different developments. Since 1970 the computer and image analysis have brought a new dimension to morphometric research. This paper describes some neuromorphometrical developments. An increasing accuracy of results regarding density and amount of neurons can be estimated with facilitated counting procedures. A similar development can be observed for the estimation of neuronal sizes and their size distribution as well as for the volume-parts of the average perikaryon volume fraction (grey cell coefficient). The morphometry of dendritic tree and the ultrastructure of neuropil are briefly mentioned.     

Epidemiologische Ansätze zur Klärung wichtiger Forschungsfragen zu COVID-19 – eine Übersicht

Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Die Epidemiologie als wissenschaftliche Disziplin ist prädestiniert dafür, Kernfragen der COVID-19-Pandemie zu...     

Sera from preeclamptic women increase the content of triglycerides and reduce the release of prostacyclin in cultured endothelial cells

The causes of the "endothelial dysfunction" accompanying preeclampsia are unknown. Women with preeclampsia have a marked hyperlipidemia which reflects altered lipid metabolism. We asked if the hyperlipidemic sera of preeclamptic women could cause altered endothelial cell properties. Cultured endothelial cells were incubated with sera from women with preeclampsia (PE) or normal pregnancies as controls. Fifty PE-sera were tested and in 45 cases the endothelial cells acquired a large number of sudanophilic granules which by electron microscopy had lipid appearance. In 31 incubations with 31 individual control sera cellular lipid granules were observed in 4 cases. The cellular triglyceride content was increased to 153 +/- 30 compared to 48 +/- 10 micrograms/mg cell protein in the control cells. Furthermore, the endothelial release of prostacyclin, measured as 6-keto PGF1 alpha, was 8.8 +/- 0.6 ng/mg cell protein in cells incubated with PE-sera as compared to 40.3 +/- 6.4 ng/mg in the control cells. Conclusion: The hyperlipidemic sera from preeclamptic women induced triglyceride accumulation in cultured endothelial cells. This was accompanied by altered endothelial function as demonstrated by reduced prostacyclin release.     

Review of select transplant subpopulations at high risk of failure from standard immunosuppressive therapy

Despite improvements in short-term graft and patient survival rates for solid organ transplants, certain subgroups of transplant recipients experience poorer clinical outcome compared to the general population. Groups including pediatrics, African-Americans, diabetics, cystic fibrosis patients, and pregnant women require special considerations when designing immunosuppressive regimens that optimize transplant outcomes. Problems specific to pediatric transplant recipients include altered pharmacokinetics of immunosuppressive drugs, such as cyclosporine (CsA) and tacrolimus (poor absorption, increased metabolism, rapid clearance), the need to restore growth post-transplantation, and a high incidence of drug-related adverse effects. African-Americans have decreased drug absorption and bioavailability, high immunologic responsiveness, and a high incidence of post-transplant diabetes mellitus. Diabetics and cystic fibrosis patients exhibit poor absorption of immunosuppressive agents, which may lead to underimmunosuppression and subsequent graft rejection. Pregnant women undergo physiologic changes that can alter the pharmacokinetics of immunosuppressives, thus requiring careful clinical management to minimize the risks of either under- or overimmunosuppression to mother and child. To achieve an optimal post-transplant outcome in these high-risk patients, the problems specific to each group must be addressed, and immunosuppressive therapy individualized accordingly. Drug formulation greatly impacts upon pharmacokinetics and the resultant level of immunosuppression. Thus, a formulation with improved absorption (e.g., CsA for microemulsion), higher bioavailability, and less pharmacokinetic variability may facilitate patient management and lead to more favorable outcomes, especially in groups demonstrating low and variable bioavailability. Other strategies aimed at improving transplant outcome include the use of higher immunosuppressive doses, different combinations of immunosuppressive agents, more frequent monitoring, and management of concurrent disease states.     

A simulation model for colorectal cancer screening: potential of stool tests with various performance characteristics compared with screening colonoscopy.

OBJECTIVE: Many new stool tests intended to detect neoplastic cells or cell products are developed at present for colorectal cancer (CRC) screening. The aim of this study was to simulate a population-based screening setting to assess and compare the potential for early detection and prevention of CRC of screening based on stool tests with different sensitivity and specificity and of screening with colonoscopy as a primary screening tool. METHOD: A Markov model was developed aimed to estimate the proportion of CRC cases which are early detected or prevented due to screening as well as the number of equired stool tests and colonoscopies per early detected or prevented CRC case. Model outcomes were calculated for the offer of annual stool testing from age 55 to 74 in combination with colonoscopic follow-up of positive test results and for the offer of screening colonoscopy as a primary screening tool at ages 55 and 65. The long-lasting risk reduction of colonoscopy allowing the removal of precancerous lesions was taken into account quantitatively. RESULTS: For a variety of stool tests with different performance characteristics, the proportion of CRC cases early detected or prevented was estimated to be higher for stool testing in combination with colonoscopic follow-up of positive test results compared with screening colonoscopy assuming levels of compliance to be expected for the respective screening scheme. Optimizing performance characteristics of stool tests in terms of detecting precancerous lesions, in addition to those in terms of detecting CRC, seemed to be crucial for maximizing effectiveness of CRC screening with stool tests. CONCLUSION: Screening based on new stool tests with colonoscopic follow-up of positive test results might offer a high potential for early detection or prevention of CRC.     

Variation of Mean Absolute Relative Differences of Continuous Glucose Monitoring Systems Throughout the Day

Background:There is an increasing use of continuous glucose monitoring (CGM) by people with diabetes. Measurement performance is often characterized by the mean absolute relative difference (MARD). However, MARD is influenced by a number of factors and little is known about whether MARD is stable throughout the day.Material and Methods:A total of 24 participants with type 1 diabetes were enrolled in the study. The study was performed for seven in-patient days. Participants wore two CGM systems in parallel and performed additional frequent blood glucose (BG) measurements. On two days, glucose excursions were induced.MARD was calculated between pairs of CGM and BG values, with BG values serving as reference values. ARD values calculated from CGM-BG pairs were grouped by hour of the day. Results were analyzed separately for glucose excursion days and for regular days.Results:Total MARDs for the complete study duration were 12.5% ± 3.6% and 13.2% ± 2.4% (n = 24). Throughout the day marked variability of MARD was observed (8.0% ± 1.3%-16.3% ± 2.9% (G5); 9.1% ± 1.4%-16.3% ± 5.3% (FL), up to n = 157 each). Low(est) MARD values were observed before breakfast and dinner, when subjects were in or near a fasting state. Especially after breakfast and lunch, MARD values were higher than average.Conclusions:Analytical performance of the two CGM systems, assessed by MARD, was found to vary markedly throughout the day. Activities of daily life likely triggered these variations. An increasing number of CGM users base therapeutic decisions on CGM values, and they should be aware of these variations of performance throughout the day.