Determination of regional bone blood flow by means of fluorescent microspheres using an automated sample-processing procedure

The determination of regional blood flow utilizing fluorescent microspheres (FMs) is an established method for numerous organs. Recent progress, in particular the automation of sample processing, has further improved this method. However, the FM method (reference sample technique), which allows repetitive measurement of regional organ blood flow, has so far not been used for the determination of blood flow in bone. The aim of the present study was to establish FM for the quantification of regional bone blood flow (RBBF). Female, anesthetized New Zealand rabbits (n = 6) received left ventricular injections of different amounts of FM at six subsequent time points. In order to examine the precision of RBBF determination, two different FM species were injected simultaneously at the sixth injection. At the end of the experiments the femoral and tibial condyles of each hind limb were removed and the fluorescence intensity in the tissue samples was measured by an automated procedure. In an in vitro study we have shown that acid digestion of the crystalline matrix has no effect on the fluorescence characteristics of FM. The determination of the number of spheres per tissue sample revealed that depending on the tissue sample size up to 3 x 10(6) spheres/injection were necessary to obtain about 400 microspheres in the individual bone samples. RBBF values of the tibial and femoral condyles did not differ at various injection intervals. The tibial blood flow values varied between 6.6 +/- 1.1 and 8.5 +/- 1.4 ml/min/100 g and were significantly higher than those of the femur (4.3 +/- 1.1 to 6.0 +/- 1.8 ml/min/100 g). The bone blood flow values obtained by simultaneous injection of two FM species correlated significantly (r = 0.96, slope = 1.06, intercept = 0.05), the mean difference was 0.39 +/- 1.11 ml/min/100 g. Our data demonstrate that the measurement of RBBF by means of FM allows a valid determination of RBBF. Copyright (C) 2003 S. Karger AG, Basel

Deceptive cultural practices that sabotage HIV/AIDS education in Tanzania and Kenya

In spite of numerous HIV/AIDS‐prevention education efforts, the HIV infection rates in Sub‐Saharan Africa remain high. Exploring and understanding the reasons behind these infection rates is imperative in a bid to offer life skills and moral education that address the root causes of the pandemic. In a recent study concerning effective HIV/AIDS‐prevention education, conducted in Tanzania and Kenya among teacher trainees and their tutors, the notion of mila potofu (defined by educators as ‘deceptive’ cultural practices) emerged as a key reason for educators’ difficulties in teaching HIV/AIDS prevention education in schools and for high HIV infection rates. Since these cultural practices cause harm, and in many cases lead to death, they are of moral concern. This paper outlines some of these cultural practices identified by educators, including ‘wife inheritance’, ‘sexual cleansing’ and the taboo against certain foods, and discusses how these practices contribute towards HIV/AIDS vulnerability. It then offers recommendations for classroom‐based life skills and moral education following Jean Piaget’s theory of cognitive development in understanding how ‘assimilation’, ‘accommodation’ and ‘adaptation’ can help people discard mila potofuin a culturally sensitive manner

Validation of an automated enzyme immunoassay for interleukin-6 for routine clinical use

Serum levels of Interleukin-6 (IL-6), a proinflammatory cytokine, are increased in early stages of inflammatory diseases such as infection and sepsis. Assay systems which permit its measurement within a few hours and as a single measurement have not been reported so far. We therefore evaluated a now commercially available automated method for IL-6 measurement on the Cobas Core(R) immunological analyzer (Roche Diagnostic Systems) which enables single IL-6 measurement within about 1 hour. The automated assay correlates well with an established, manual microtiter plate assay (Biosource GmbH) which uses the same antibodies and reagents (r=0.98). Accuracy of the automated method was established by adding known amounts of IL-6 international reference preparation. Recovery of the international standard was in the range of 92-104%. The automated assay had a precision of singletons below 6% and was linear up to 2800 pg/ml. This automated assay provides a suitable, convenient and time saving method for measurement of IL-6 serum levels in the routine clinical laboratory

Haben die Konzentrationen von Interleukin 6, Procalcitonin und CRP bei Intensivpatienten während des ersten Fieberanstieges eine prognostische Bedeutung?

Serum levels of interleukin 6 (IL-6), procalcitonin (PCT), and C-reactive protein (CRP) were measured in 38 critically ill patients immediately after an increase in body temperature above 38.3 degrees C. Ten healthy controls were also included for comparison. The onset of fever was accompanied by elevated circulating levels of all the 3 markers in comparison to healthy control subjects. However, only IL-6 levels were significantly higher (p<0.05) in nonsurvivors compared with survivors. Sensitivity, specificity, positive, and negative predictive values for survival were higher for IL-6 in comparison to levels of PCT and CRP. Areas under receiver characteristic operating curves revealed the highest area under the curve for IL-6 compared to PCT and CRP. These data suggest that IL-6 rather than PCT or CRP may be an early predictor of prognosis and mortality in patients with the onset of fever

Spielen CRP-Spiegel neben IL-6 und PCT noch eine Rolle für Patienten auf Intensivstationen? / Are circulating levels of CRP compared to IL-6 and PCT still relevant in intensive care unit patients?

In der Diagnostik von Infektionen und inflammatorischen Prozessen ist das C-reaktive Protein (CRP) einer der meistverwendeten Parameter, unter anderem aufgrund der geringen Kosten und der schnellen Verfügbarkeit. Im Zuge der letzten Jahre gewannen jedoch andere Entzündungsparameter, wie zum Beispiel das Interleukin 6 (IL-6) oder Procalcitonin (PCT), zunehmend an Bedeutung. Obwohl diese Parameter im klinischen Alltag noch nicht überall etabliert sind, besitzen sie doch wesentliche Vorteile in der Diagnostik und im Verlaufsmonitoring von entzündlichen Erkrankungen. Beispielsweise ist die Erkennung entzündlicher Komplikationen auf Intensivstationen durch erhöhte IL-6 Spiegel 24 bis 48 Stunden vor einer Erhöhung des CRP möglich. Die deutliche Überlegenheit von PCT gegenüber CRP in der Diagnostik von bakteriellen Infektionen und Sepsis begründet sich in der höheren Spezifität des PCT für bakterielle Infektionen. Der PCT-Verlauf ermöglicht daher eine bessere Beurteilung des Therapieerfolges und Krankheitsverlaufs des Patienten und liefert Hinweise auf eine gegebenenfalls erforderliche Therapieumstellung. Daraus ergibt sich die Frage, ob die Messung des CRP-Spiegels durch IL-6 und/oder PCT ersetzt werden kann. In dieser Übersichtsarbeit wird die derzeitige Bedeutung von CRP im Verhältnis zu den neueren Entzündungsparametern in der Diagnostik von bakteriellen Infektionen, im therapeutischen Monitoring und in seiner Aussagekraft bezüglich der Prognose des Patienten auf Intensivstationen dargestellt.C-reactive protein (CRP) currently constitutes one of the most widely used parameters for the diagnosis of infections and inflammatory processes, due to simple methods and low costs. However, in recent years, other parameters, such as interleukin 6 (IL-6) and procalcitonin (PCT), have gained in importance. Although these parameters are presently not established everywhere in clinical routine, they provide significant advantages in the diagnosis and monitoring of inflammatory diseases. For instance, in intensive care, the increase in IL-6 levels may indicate inflammatory complications 24 to 48 h prior to the increase in circulating CRP levels. In contrast to CRP, PCT shows a higher specificity for bacterial infections, which facilitates the diagnosis of bacterial infections and sepsis. Therefore, PCT values provide a better evaluation of prognosis and therapeutic success and of a necessary change in therapy. These points raise the question whether CRP levels should at least in part be replaced by PCT and/or IL-6. Thus, this review seeks to examine the value of CRP in relation to PCT and IL-6 in the diagnosis of bacterial infections, in therapeutic monitoring, and regarding prognosis in critical care patients

Ezetimibe reduces cholesterol content and NF-kappaB activation in liver but not in intestinal tissue in guinea pigs

Background: Statins (HMG CoA reductase inhibitors), in addition to reducing circulating cholesterol and incidence of coronary heart disease, also have pleiotropic, anti-inflammatory effects. Patients with chronic liver diseases, non-alcoholic fatty liver disease (NAFLD) or hepatitis C are often excluded from statin therapy because of adverse effects in a small cohort of patients despite increased cardiovascular risk cholesterol. Ezetimibe, which inhibits cholesterol absorption by inhibition of Niemann-Pick C1 like 1 (NPC1L1) protein in the brush border of intestinal cells, has been suggested as a new therapeutic option in these patients. Methods: Effects of ezetimibe on lipoprotein metabolism, hepatic and intestinal lipid content in guinea pigs, an animal model with a lipoprotein profile and pattern similar to humans were investigated. In order to investigate a possible effect of ezetimibe on cholesterol induced inflammation NF-kappaB activation as an indicator for inflammatory processes in liver and gut tissue was measured. Results: Lipid enriched diet led to accumulation of lipids in hepatic tissue which caused strong hepatic NF-kappaB activation. Ezetimibe reduced lipid diet induced increase of circulating cholesterol by about 77% and prevent hepatic NF-kappaB activation almost completely. In contrast in intestinal cells Ezetimibe, though lowering diet induced cholesterol accumulation, increased triglyceride content and subsequent NF-kappaB activation. Conclusion: In summary these data show, that ezetimibe effectively reduced diet induced circulating cholesterol levels, hepatic lipid accumulation and inflammatory response in our guinea pig model. However this drug elicited a local inflammatory response in intestinal tissue. Whether these diverse effects of ezetimibe on inflammatory parameters such as NF-kappaB have clinical relevance remains to be determined

Toll-Like Receptor Expression in Human Keratinocytes: Nuclear Factor κB Controlled Gene Activation by Staphylococcus aureus is Toll-Like Receptor 2 But Not Toll-Like Receptor 4 or Platelet Activating Factor Receptor Dependent

Cultured primary human keratinocytes were screened for their expression of various members of the toll-like receptor (TLR) family. Keratinocytes were found to constitutively express TLR1, TLR2, TLR3, TLR5, and TLR9 but not TLR4, TLR6, TLR7, TLR8, or TLR10 as shown by polymerase chain reaction analysis. The expression of the crucial receptor for signaling of staphylococcal compounds TLR2 was also confirmed by immunohistochemistry, in contrast to TLR4, which showed a negative staining pattern. Next, we analyzed the activation of the proinflammatory nuclear transcription factor κB by Staphylococcus aureus strain 8325-4. Using nuclear extract gel shifts, RelA staining, and luciferase reporter transfection plasmids we found a clear induction of nuclear factor κB translocation by the bacteria. This translocation induced the transcription of nuclear factor κB controlled genes such as inducible nitric oxide synthetase, COX2, and interleukin-8. Transcription of these genes was followed by production of increased amounts of interleukin-8 protein and NO. Inhibition experiments using monoclonal antibodies and the specific platelet activating factor receptor inhibitor CV3988 showed that nuclear factor κB activation by S. aureus was TLR2 but not TLR4 or platelet activating factor receptor dependent. In line, the purified staphylococcal cell wall components lipoteichoic acid and peptidoglycan, known to signal through TLR2, also showed nuclear factor κB translocation in human keratinocytes, indicating a crucial role of the staphylococcal cell wall in the innate immune stimulation of human keratinocytes. These results help to explain the complex activation of human keratinocytes by S. aureus and its cell wall components in various inflammatory disorders of the skin

Integrated Management and Visualization of Electronic Tag Data with Tagbase

Electronic tags have been used widely for more than a decade in studies of diverse marine species. However, despite significant investment in tagging programs and hardware, data management aspects have received insufficient attention, leaving researchers without a comprehensive toolset to manage their data easily. The growing volume of these data holdings, the large diversity of tag types and data formats, and the general lack of data management resources are not only complicating integration and synthesis of electronic tagging data in support of resource management applications but potentially threatening the integrity and longer-term access to these valuable datasets. To address this critical gap, Tagbase has been developed as a well-rounded, yet accessible data management solution for electronic tagging applications. It is based on a unified relational model that accommodates a suite of manufacturer tag data formats in addition to deployment metadata and reprocessed geopositions. Tagbase includes an integrated set of tools for importing tag datasets into the system effortlessly, and provides reporting utilities to interactively view standard outputs in graphical and tabular form. Data from the system can also be easily exported or dynamically coupled to GIS and other analysis packages. Tagbase is scalable and has been ported to a range of database management systems to support the needs of the tagging community, from individual investigators to large scale tagging programs. Tagbase represents a mature initiative with users at several institutions involved in marine electronic tagging research

Influence of non-nucleoside reverse transcriptase inhibitors (efavirenz and nevirapine) on the pharmacodynamic activity of gliclazide in animal models

<p>Abstract</p> <p>Background</p> <p>Type 2 diabetes may occur as a result of HIV infection and/or its treatment. Gliclazide is a widely used drug for the treatment of type 2 diabetes. Efavirenz and nevirapine are widely used non-nucleoside reverse transcriptase inhibitors for the treatment of HIV infection. The role of Efavirenz and nevirapine on the pharmacodynamic activity of gliclazide is not currently known. The objective of this study was to examine the effect of oral administration of efavirenz and nevirapine on blood glucose and investigate their effect on the activity of gliclazide in rats (normal and diabetic) and rabbits to evaluate the safety and effectiveness of the combination.</p> <p>Methods</p> <p>Studies in normal and alloxan induced diabetic rats were conducted with oral doses of 2 mg/kg bd. wt. of gliclazide, 54 mg/kg bd. wt. of efavirenz or 18 mg/kg bd. wt. of nevirapine and their combination with adequate washout periods in between treatments. Studies in normal rabbits were conducted with 5.6 mg/1.5 kg bd. wt. of gliclazide, 42 mg/1.5 kg bd. wt. of efavirenz or 14 mg/1.5 kg bd. wt. of nevirapine and their combination given orally. Blood samples were collected at regular time intervals in rats from retro orbital puncture and by marginal ear vein puncture in rabbits. All the blood samples were analysed for blood glucose by GOD/POD method.</p> <p>Results</p> <p>Efavirenz and nevirapine alone have no significant effect on the blood glucose level in rats and rabbits. Gliclazide produced hypoglycaemic/antidiabetic activity in normal and diabetic rats with peak activity at 2 h and 8 h and hypoglycaemic activity in normal rabbits at 3 h. In combination, efavirenz reduced the effect of gliclazide in rats and rabbits, and the reduction was more significant with the single dose administration of efavirenz than multiple dose administration. In combination, nevirapine has no effect on the activity of gliclazide in rats and rabbits.</p> <p>Conclusion</p> <p>Thus, it can be concluded that the combination of efavirenz and gliclazide may need dose adjustment and care should be taken when the combination is prescribed for their clinical benefit in diabetic patients. The combination of nevirapine and gliclazide was safe. However, further studies are warranted.</p

High frequency of Fredrickson's phenotypes IV and IIb in Brazilians infected by human immunodeficiency virus

BACKGROUND: Human immunodeficiency virus (HIV) infection is very prevalent in Brazil. HIV therapy has been recently associated with coronary heart disease (CHD). Dyslipidemia is a major risk factor for CHD that is frequently described in HIV positive patients, but very few studies have been conducted in Brazilian patients evaluating their lipid profiles. METHODS: In the present work, we evaluated the frequency and severity of dyslipidemia in 257 Brazilian HIV positive patients. Two hundred and thirty-eight (93%) were submitted to antiretroviral therapy (224 treated with protease inhibitors plus nucleoside reverse transcriptase inhibitors, 14 treated only with the latter, 12 naive and 7 had no records of treatment). The average time on drug treatment with antiretroviral therapy was 20 months. None of the patients was under lipid lowering drugs. Cholesterol, triglyceride, phospholipid and free fatty acids were determined by enzymatic colorimetric methods. Lipoprotein profile was estimated by the Friedewald formula and Fredrickson's phenotyping was obtained by serum electrophoresis on agarose. Apolipoprotein B and AI and lipoprotein "a" were measured by nephelometry. RESULTS: The Fredrickson phenotypes were: type IIb (51%), IV (41%), IIa (7%). In addition one patient was type III and another type V. Thirty-three percent of all HIV+ patients presented serum cholesterol levels ≥ 200 mg/dL, 61% LDL-cholesterol ≥ 100 mg/dL, 65% HDL-cholesterol below 40 mg/dL, 46% triglycerides ≥ 150 mg/dL and 10% have all these parameters above the limits. Eighty-six percent of patients had cholesterol/HDL-cholesterol ratio ≥ 3.5, 22% increased lipoprotein "a", 79% increased free fatty acids and 9% increased phospholipids. The treatment with protease inhibitors plus nucleoside reverse transcriptase inhibitors increased the levels of cholesterol and triglycerides in these patients when compared with naïve patients. The HDL-cholesterol (p = 0.01) and apolipoprotein A1 (p = 0.02) levels were inversely correlated with the time of protease inhibitor therapy while total cholesterol levels had a trend to correlate with antiretroviral therapy (p = 0.09). CONCLUSION: The highly varied and prevalent types of dyslipidemia found in Brazilian HIV positive patients on antiretroviral therapies indicate the urgent need for their early diagnosis, the identification of the risk factors for CHD and, when needed, the prompt intervention on their lifestyle and/or with drug treatment