Preliminary results on a new method for producing yttrium phosphorous microspheres.

This paper reports on a new method to embed phosphorus particles into the matrix of yttrium aluminum silicate microspheres. Yttrium phosphorus glass microspheres about 20µm in size were obtained when an aqueous solution of YCl3 and AlCl3 were added to tetraethyl orthosilicate (TEOS) (phosphoric acid was used to catalyze the hydrolysis and condensation of TEOS) and was pumped into silicone oil under constant stirring. The shapes of the particles produced by this method are regular and nearly spheric in shape. Paper chromatography was used to determine the radiochemical impurity of radioactive microspheres. Radionuclide purity was determined using a gamma spectrometry system and an ultra-low level liquid scintillation spectrometer. The P(+) ions implantation stage was eliminated by embedding phosphorus particles in the matrix of the glass microspheres. This paper shows that a high temperature is not required to produce yttrium phosphorus aluminum silicate microspheres. The result shows that the silicone oil spheroidization method is a very suitable way to produce yttrium phosphorus glass microspheres. The topographical analysis of microspheres shows that the Y, P, Si, and Al elements are distributed in the microspheres and the distribution of elements in the samples is homogenous.

Production and quality control of radioactive yttrium microspheres for medical applications.

In this paper, a method for production of yttrium silicate microspheres is reported. Yttrium silicate microspheres with approximate sizes of 20-50µm were obtained when an aqueous solution of Y(NO3)3 was added to tetraethyl orthosilicate (TEOS) and was pumped into silicone oil under constant stirring. The shapes of the particles produced by the proposed method were regular and nearly spherical. The spherical shapes, composition and element distribution were investigated by scanning electron microscopy (SEM), carbon/sulfur analysis and SEM/EDS mapping analysis. Paper chromatography was used to identify radiochemical impurities in the radioactive microspheres. The radionuclide purity was determined using a gamma spectrometry system and an ultra-low-level liquid scintillation spectrometer. The results indicated that the proposed silicone oil spheroidization method is suitable for the production of yttrium silicate microspheres.

Mechanisms of muscular electrophysiological and mitochondrial dysfunction following exposure to malathion, an organophosphorus pesticide.

Muscle dysfunction in acute organophosphorus (OP) poisoning is a cause of death in human. The present study was conducted to identify the mechanism of action of OP in terms of muscle mitochondrial dysfunction. Electromyography (EMG) was conducted on rats exposed to the acute oral dose of malathion (400 mg/kg) that could inhibit acetylcholinesterase activity up to 70%. The function of mitochondrial respiratory chain and the rate of production of reactive oxygen species (ROS) from intact mitochondria were measured. The bioenergetic pathways were studied by measurement of adenosine triphosphate (ATP), lactate, and glycogen. To identify mitochondrial-dependent apoptotic pathways, the messenger RNA (mRNA) expression of bax and bcl-2, protein expression of caspase-9, mitochondrial cytochrome c release, and DNA damage were measured. The EMG confirmed muscle weakness. The reduction in activity of mitochondrial complexes and muscular glycogen with an elevation of lactate was in association with impairment of cellular respiration. The reduction in mitochondrial proapoptotic stimuli is indicative of autophagic process inducing cytoprotective effects in the early stage of stress. Downregulation of apoptotic signaling may be due to reduction in ATP and ROS, and genotoxic potential of malathion. The maintenance of mitochondrial integrity by means of artificial electron donors and increasing exogenous ATP might prevent toxicity of OPs.

Effects of Papaver rhoeas (L.) extract on formalin-induced pain and inflammation in mice.

Stress amelioration can improve its metabolic as well as other side effects. In the present study, the effects of hydro-alcoholic extract of Papver rhoeas (L.) on formalin-induced pain and inflammation were investigated in male Swiss-Webster mice (20-25 g). Formalin injects in the plantar portion of mice hind paw and pain was studied for 60 min. The plant extract and other drugs were administered intraperitoneally 30 min before formalin. Experiments showed that administration of extract (25, 50 and 100 mg kg(-1)) could induced analgesia in a dose-response manner in both phases of formalin test. More over, the extract inhibits inflammation induced by formalin injection. Naloxone (4 mg kg(-1)), dextromethorphan (20 mg kg(-1)) and NG-nitro-L-arginine-methylester (L-NAME; 10 mg kg(-1)) reduced the extract analgesia in first but not late phase. Extract administration also increased plasma corticosterone level in dose-dependent manner. It could be concluded that Papaver rhoeas (L.) extract could inhibits acute phase of formalin test in mice by opioidergic, glutamatergic and nitricergic mechanisms. In addition, the extract can induce corticosterone plasma level which may be responsible for inhibition of inflammation and chronic phase of pain induced by formalin.

[Oral surgery as the patient's immediate cause of death]. / Kaakchirurgische behandelingen als oorzaak van overlijden.

The purpose of this study was to determine how often patients have died after treatment by an oral surgeon in the Netherlands. A review of the literature showed that this kind of complication has rarely been described in international literature. Subsequently, a small questionnaire was sent to 274 Dutch oral surgeons; 140 questionnaires were returned (51% response). The oral surgeons participating in the survey had had, on average, 21 years of work experience and 4.3% were women. Forty percent of the respondents confirmed that they had experienced the death of a patient after oral surgery. Most (18 patients) died after a dental extraction. The most important causes of death were post-operative spreading of an infection (15 patients), failing to survive oncology treatment (9 patients) and as the third cause of death, heart and/or lung failure was named (6 patients).

Live and heat-inactivated lactobacilli from feces inhibit Salmonella typhi and Escherichia coli adherence to Caco-2 cells.

A quantitative approach has been proposed to evaluate the competitive inhibition of Escherichia coli and Salmonella typhi by live and heat-inactivated laboratory isolated Lactobacillus sp. on adhesion to monolayer of Caco-2 cells. Three species of Lactobacillus (L. casei, L. acidophilus, L. agilis) isolated from human neonate feces and two commercial probiotic strains (L. casei, L. acidophilus) have been compared for probiotic activity. All lactobacilli were able to attach to the Caco-2 cells, however, the degree of adhesion was bacterial strain-dependent. The adhesion indices of the two commercial probiotic strains were not significantly different from the values obtained for the other two similar fecal strains (p > 0.01). The inhibition of attachment of the pathogenic bacteria by inactivated cells of fecal L. acidophilus was examined and compared to the results of live bacteria. The inhibition pattern was similar for live and heat-inactivated L. acidophilus (p > 0.01). The number of attached pathogenic bacteria to the Caco-2 cells decreased when the number of L. acidophilus increased from 10(6) to 10(9) CFU/mL. The heat-inactivated L. acidophilus displayed similar probiotic activity compared to the live bacteria.

Simultaneous modelling of operative mortality and long-term survival after coronary artery bypass surgery.

Typical analyses of lifetime data treat the time to death or failure as the response variable and use a variety of modelling strategies such as proportional hazards or fully parametric, to investigate the relationship between the response and covariates. In certain circumstances it may be more natural to view the distribution of the response variable as consisting of two or more parts since the survival curve appears segmented. This article addresses such a scenario and we propose a model for simultaneously investigating the effects of covariates over the two segments. The model is an analogue of that proposed by Lambert for zero-inflated Poisson regression. The application is central to the model development and is concerned with survival after coronary artery bypass surgery. Here operative mortality, defined as death within 30 days after surgery, and long-term mortality, are viewed as distinct outcomes. For the application considered, the survivor function displays much steeper descent during the first 30 days after surgery, that is, for operative mortality, than after this period. An investigation of the effects of covariates on operative and long-term mortality after coronary artery bypass surgery illustrates the usefulness of the proposed model.

More on the measurement of ionized magnesium in whole blood.

Current technology has made it possible to measure ionized magnesium with user-friendly ion selective electrode technology. Although this technology has not reached a perfect status literature shows that it can be used in clinical routine especially in serum. This paper deals with issues concerning the measurement of ionized magnesium in whole blood. To measure in whole blood apart from an instrument with good general performance data an adequate sample treatment is especially critical. We tested a number of different sample containers and found that they interfere in different degrees with the magnesium determination. In some cases this is due to silicone giving falsely high ionized magnesium values which may be twice the real value and even higher. Another problem is the heparinization of the sample. We found that different heparins may alter the result in a different way. The well known complexing capability of heparin may lead to a reduction of the ionized magnesium within the sample and thus to false low results. But some heparins cause elevated results. The reason for this may be zinc. Test procedures to check the quality of anticoagulants are given. Due to these procedures sample containers could be found which do not interfere with the determination of ionized magnesium in whole blood - thus making the measurement possible. All these factors indicate that the measurement of ionized magnesium really needs a very well defined sample handling - otherwise false results may arise. This is not only true for the measurement of whole blood but also for plasma or even for "so called serum" as there might be a sample container within the chain from patient to the instrument which is unsuitable- and thus will alter the result.

Chronic fatigue syndrome associated with a psychotic state resulting in multiple murders.

A 28-year-old, ambitious, academically successful Asian man with a zeal for hard work develops infectious mononucleosis and its resultant lethargy and fatigue. He becomes depressed, then develops symptoms of mania before turning floridly psychotic. In his psychotic state he develops grandiose delusions about being the second son of God after Christ and takes it upon himself to rid the world of all evil by defeating the anti-Christ. He kills four people and seriously injures a fifth. He is arrested and found not guilty by reason of insanity. He remains a diagnostic puzzle for a long time before starting to respond to neuroleptic medication.

Local anesthetic-phospholipid interactions. The pH dependence of the binding of dibucaine to dimyristoylphosphatidylcholine vesicles.

The interaction of the local anesthetic dibucaine with unilamellar vesicles of dimyristoylphosphatidylcholine was studied by equilibrium dialysis. Saturating binding profiles (as a function of dibucaine) were found, with apparent association constant ranging from 1.26 X 10(3)M-1 to 2.57 X 10(3)M-1 as pH is increased from 5.0 to 7.5. The number of phospholipid molecules comprising a binding site was found to be about 5 at each pH. Analysis of the data was also achieved using the Stern model, which takes into account the electrostatic effect on binding of the cationic drug due to the build up of a surface potential.