Acyltransferase activities in the yolk sac membrane of the chick embryo

The activities of some enzymes of glycerolipid synthesis and fatty acid oxidation were measured in subcellular fractions of the yolk sac membrane (YSM), an extra-embryonic tissue that mediates the transfer of lipid from the yolk to the circulation of the chick embryo. The activities of monoacylglycerol acyltransferase and carnitine palmitoyl transferase-1 in the YSM (respectively, 284.8±13.2 nmol/min/mg microsomal protein and 145.6±9.1 nmol/min/mg mitochondrial protein; mean ±SE; n=4) at day 12 of development appear to be the highest yet reported for any animal tissue. Also, the carnitine palmitoyl transferase-1 of the YSM was very insensitive to inhibition by malonyl CoA. The maximal activities of glycerol-3-phosphate acyltransferase and diacylglycerol acyltransferase in the YSM (respectively, 26.7±2.2 and 36.1±2.1 nmol/min/mg microsomal protein) were also high compared with the reported values for various animal tissues. The very high enzymic capacity for glycerolipid synthesis supports the hypothesis that the yolk-derived lipids are subjected to hydrolysis followed by reesterification during transit across the YSM. The monoacylglycerol pathway appears to be the main route for glycerolipid resynthesis in the YSM. The results also suggest that the YSM has the capacity to perform simultaneously β-oxidation at a high rate in order to provide energy for the lipid transfer process.     

Gallbladder diverticulum: a case report and review of the literature

BACKGROUND: The clinical significance of the 14 and 6 positive spikes (PS) electroencephalographic (EEG) phenomenon is not well established. This study was performed to provide further data regarding the clinical correlates of the PS, particularly attention-deficit/hyperactivity and somatic symptoms. METHODS: Diagnostic information gathered through structured interviews was compared among four groups of psychiatric inpatients aged 4-17 years who underwent an EEG examination over a 2-year period. Groups consisted of patients with: 1) 14 and 6 PS (n = 25); 2) epileptic discharges (n = 29); 3) slow-wave abnormalities (n = 23); and 4) a normal EEG group age and sex matched to the 14 and 6 PS group (n = 25). RESULTS: Attention-deficit hyperactivity disorder (ADHD) symptoms were significantly more frequent in the PS group (chi 2 = 2.96, p < .05) compared to the other three groups combined. Although somatic symptoms were not increased in the 14 and 6 PS group, anxiety symptoms tended to occur more in this group (chi 2 = 3.50, p < .06). CONCLUSIONS: The PS profile appears associated with ADHD symptoms. Possible treatment implications of this finding (e.g., use of anticonvulsants in ADHD patients with PS) need to be explored.     

Pigmented uveal tumours in a transgenic mouse model

Lectins are sensitive probes which bind carbohydrate structures specifically. In this study, we modified the lectin staining procedure for sensitive detection of carbohydrate structures in formalin-fixed, paraffin-embedded sections of normal and heterologous serum-induced fibrotic livers. The liver sections were heated in hot distilled water at 100 degrees C for 10 min (thermo-treatment: TT), and then stained with 24 different lectins. In comparison with the results from sections without TT (nonTT), enhanced and/or alternated staining patterns of 19 lectins were demonstrated in sections with TT, and enhanced staining of Vicia villosa agglutinin seen in Kupffer cells was noted. Interestingly, no positive staining was seen with Dolichos biflorus agglutinin, peanut agglutinin or soybean agglutinin (SBA), which recognize O-linked carbohydrate chains, in Kupffer cells of non-TT sections, but strong positive staining was demonstrated in those of TT sections. SBA-positive staining in the cytoplasm of some scattered hepatocytes located in the periportal and perifibrous zones and central zone of pseudolobules was demonstrated only in the fibrotic liver sections with TT. Such findings indicate the heterogeneity of hepatocytes in the liver with fibrosis. Formalin fixation causes masking of lectin binding sites, especially O-linked carbohydrate chains, and TT may recover such masking reactions. TT improved the staining reactions for many lectins in formalin-fixed, paraffin-embedded liver sections, and new staining patterns appear after TT. Modified TT staining procedures may be useful for the diagnosis and prognosis of liver fibrosis.     

Diffusive vs. convective therapy: effects on mediators of inflammation in patient with severe systemic inflammatory response syndrome

OBJECTIVE: To compare two forms of continuous renal replacement therapy, continuous venovenous hemofiltration (CVVH) vs. continuous venovenous hemodialysis (CVVHD), in terms of the removal of inflammatory mediators from the blood of patients with systemic inflammatory response syndrome and acute renal failure. DESIGN: Randomized crossover, clinical study. SETTING: University teaching hospital. PATIENTS: Thirteen patients with systemic inflammatory response syndrome and acute renal failure receiving continuous renal replacement therapy. INTERVENTION: Patients were randomized to receive either convective clearance using CVVH or diffusive clearance using CVVHD for the first 24 hrs, followed by the other modality for 24 hrs. All treatments utilized AN69 hemofilters. CVVH was performed with an ultrafiltration rate of 2 L/hr and CVVHD with a dialysis outflow rate of 2 L/hr. MEASUREMENTS AND MAIN RESULTS: Plasma and ultrafiltrate concentrations of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-10, and sL-selectin were measured at 0, 1, 3, 6, 12, and 24 hrs by radioimmunoassay. Plasma endotoxin concentrations were also measured at 0, 12, and 24 hrs by chromogenic assay. CVVH was associated with a 13% decrease in plasma TNF-alpha concentrations compared with a 23% increase while on CVVHD (p < .05). Mean plasma concentrations of IL-6, IL-10, and sL-selectin were unchanged over time and between therapies. Only minimal amounts of mediators were recovered in the effluents with either therapy except for IL-6. The clearances for IL-6 were different between therapies, 1.9+/-0.8 (SD) mL/min for CVVHD and 3.3+/-1.5 mL/min for CVVH, (p< .01). Plasma endotoxin concentrations were not different between therapies. CONCLUSION: CVVH resulted in a decrease in plasma TNF-alpha concentrations as compared with CVVHD, while the type of transport mechanism used did not influence plasma concentrations of IL-6, IL-10, soluble L-selectin, or endotoxin. Differences in clearance for IL-6 between CVVH and CVVHD did not translate into significant changes in circulating IL-6 concentrations.     

Pulmonary thrombo-endarterectomy]

Chronic pulmonary thromboembolism is an underdiagnosed condition with major morbidity and mortality. Over the past year and a half, we diagnosed 6 new cases of which 3 underwent successful, pulmonary thrombo-endarterectomy (2 in San Diego, 1 in Jerusalem). All recovered fully and returned to normal, active life. We conclude that pulmonary thrombo-endarterectomy is a viable option for patients with chronic pulmonary thromboembolism.     

Emission, fate and effects of soluble silicates (waterglass) in the aquatic environment

Soluble silicates, commercially known as waterglass, are among the largest volume synthetic chemicals in the world. Silicon from waterglass is rapidly transformed to the biologically active orthosilicic acid (referred to as dissolved silicate). This paper aims to assess the impact of waterglass on the aquatic environment in Western Europe. The emission to surface waters from the four most relevant application areas, household detergents, pulp and paper production, water and wastewater treatment, and soil stabilization, is estimated to be ca. 88-121 kton of SiO2 per year. This is a small fraction (<2%) of the estimated total amount of dissolved silicate transported by rivers to the oceans. Locally, increases in dissolved silicate concentration will decrease the ratios of N:Si and P:Si, which could influence phytoplankton species composition and favor the growth of diatoms over other groups of algae. Significant adverse effects in aquatic ecosystems are not expected.     

Structural relationships between measures based on heart beat intervals: potential for improved risk assessment

Decreased left ventricular ejection fraction is the most commonly used risk factor for identification of patients at high-risk for lethal ventricular arrhythmic events. Twenty-four-hour electrocardiographic (ECG) approaches to risk stratification include: counts of ventricular premature contractions (VPCs), measures of heart rate variability (HRV), and heart rate turbulence (HRT) which has two components, turbulence onset and turbulence slope (TS). Refinement of these ECG risk stratifiers could enhance their clinical utility. We explored the structural relationships between heart rate (HR) and HRV and HRT measures. Our goal was to separate out the component of these measures due to the underlying average heart rate (HR), thus potentially reducing the variability of the measures and increasing their power to stratify risk. We proposed re-scaling tachograms of heart-beat intervals so that the re-scaled tachogram has a HR of 75 (or equivalently an average interval of 800 ms) and calculating HRV and HRT from the rescaled time series. We also explored the relationship between the number of VPCs and HRT. We showed that TS is structurally related to the number of VPCs (and hence to the length of the ECG recording). We proposed an adjusted TS that is independent of the number of VPCs. We also addressed the ability of shorter ECG recording to estimate HRV and HRT measures. We evaluated standard and rescaled HRV and HRT measures using qualifying ambulatory ECG recordings from 744 patients in the Cardiac Arrhythmia Suppression Trial. We found that measures based on the rescaled tachogram had reduced variance (20% to 40%). Correlations between measures were also substantially reduced. We also found substantial circadian effects on some, but not all HRV indices, not explained by the circadian pattern in HR and possibly pointing to additional measures for risk prediction. In conclusion, we found that adjusting for HR and the number of VPCs in heart-beat related ambulatory ECG measures has the potential to significantly improve the power of these measures to risk stratify cardiac patients.     

Waveband selection for determination of nitrate in soil using mid-infrared attenuated total reflectance spectroscopy

This paper investigates the possibility of determining nitrate concentration in soil pastes using spectral absorbance at several fixed wavebands. A three-step procedure for determining the most appropriate wavebands, as well as their width, is described. This procedure is applied to a dataset that includes eleven soils with various nitrate concentrations ranging from 0 to approximately 150 mg [N]/kg [dry soil]. The results show that nitrate concentration can be determined quite acceptably using only four 12 cm(-1) wide wavebands, centered at 1280, 1330, 1379, and 1430 cm(-1). The prediction errors range from approximately 1.5 to 14.0 mg [N]/kg [dry soil], depending on soil composition and moisture content, with the lighter and more vulnerable (pollution-wise) soils having errors inferior to 10 mg [N]/kg [dry soil]. These results are similar to results obtained by applying partial least square to the 'continuous' spectrum, and indicate that the development of a soil nitrate attenuated total reflectance (ATR) sensor based on a few fixed mid-infrared (MIR) wavebands could be considered.     

Calibration of dosemeters used in mammography with different X ray qualities: EUROMET project no. 526

The effect of different X ray radiation qualities on the calibration of mammographic dosemeters was investigated within the framework of a EUROMET (European Collaboration in Measurement Standards) project. The calibration coefficients for two ionization chambers and two semiconductor detectors were established in 13 dosimetry calibration laboratories for radiation qualities used in mammography. They were compared with coefficients for other radiation qualities, including those defined in ISO 4037-1, with first half value layers in the mammographic range. The results indicate that the choice of the radiation quality is not crucial for instruments with a small energy dependence of the response. However, the radiation quality has to be chosen carefully if instruments with a marked dependence of their response to the radiation energy are calibrated.     

Errors in intelligence estimation with short forms of the WAIS.

Because the full Wechsler Adult Intelligence Scale (WAIS) generally takes more than an hour of the clinician's time to administer, short forms based on a selection of subscales are often substituted. The present study shows that in many cases such short forms may give seriously inaccurate results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)