Heat Stroke with Status Epilepticus Secondary to Posterior Reversible Encephalopathy Syndrome (PRES).

Heat stroke is a life threatening, multisystem disorder characterized by severe hyperthermia (core body temperature > 41.1°C) with central nervous system dysfunction and/or other end organ damage. Neurological complications, such as disturbances of consciousness, convulsion, profound mental change, disorientation, or even prolonged coma, were present in almost all cases of exertional heat stroke (EHS). We present a case of EHS with severe rhabdomyolysis and acute oliguric kidney injury in a 20-year-old healthy marathon runner, who developed status epilepticus on Day 4 of his admission. The patient was managed in ICU with renal replacement therapy and aggressive seizure control. He made a full recovery after 2 weeks of ICU stay. Diagnosis of EHS with posterior reversible encephalopathy syndrome (PRES) secondary to acute kidney injury was made.

Functional analysis and molecular characterization of two acetylcholinesterases from the German cockroach, Blattella germanica.

Two acetylcholinesterases (AChEs; BgAChE1 and BgAChE2) from Blattella germanica were functionally expressed using the baculovirus system. Kinetic analysis demonstrated that BgAChE2 had higher catalytic efficiency but lower substrate specificity than BgAChE1. With the exceptions of paraoxon and propoxur, BgAChE1 was generally less sensitive to inhibitors than BgAChE2. Western blot analysis using anti-BgAChE antibodies revealed that BgAChE1 was far more abundant in all examined tissues compared to BgAChE2, which is only present in the central nervous system. Both BgAChEs existed in dimeric form, covalently connected via a disulphide bridge under native conditions. Most fractions of BgAChE1 had a glycophosphatidylinositol (GPI) anchor, but a small fraction comprised a collagen-like tail. BgAChE2 appeared to have a collagen-GPI-fused tail. Based on the kinetic and molecular properties, tissue distribution and abundance, BgAChE1 was confirmed to play a major role in postsynaptic transmission.

Vertebroplasty: magnetic resonance findings related to cement leakage risk.

PURPOSE: To find magnetic resonance (MR) findings predicting cement leakage in patients receiving percutaneous vertebroplasty (PVP) due to osteoporotic compression fractures. MATERIAL AND METHODS: MR was done in 43 patients (age 52-89 years) before PVP (56 vertebrae), which was done via a bipedicular approach with fluoroscopic monitoring. Shortly after the procedure, a non-contrast-enhanced computed tomography (CT) scan was done at the vertebroplasty sites for evaluation of bone cement leakage. The following MR findings of fractured vertebral bodies were retrospectively reviewed for correlation with leakage risk: severity of bone-marrow edema, presence of a T2-weighted low-signal-intensity line, percentage residual vertebral body height, presence of either a vacuum or cystic change within the vertebral body, and presence of a cortical disruption. RESULTS: After PVP, cement leakage was detected in 35 vertebrae (62.5%). Leakage was most frequently observed in the anterior external vertebral venous plexus (46%). Cement leakage rate increased when there was a cortical disruption (P = 0.037), especially at the endplates, while it decreased when there was a vacuum or a cystic change within the fractured vertebra (P = 0.019). Other MR findings were not related to the risk of cement leakage. CONCLUSION: The risk of cement leakage in PVP increases when MR shows cortical disruption in a fractured vertebral body, especially at the endplates. It decreases when MR shows a vacuum or cystic change within the body.

Molecular, biochemical and histochemical characterization of two acetylcholinesterase cDNAs from the German cockroach Blattella germanica.

Full length cDNAs encoding two acetylcholinesterases (AChEs; Bgace1 and Bgace2) were cloned and characterized from the German cockroach, Blattella germanica. Sequence analyses showed that both genes possess all the typical features of ace, and that Bgace1 is orthologous to the insect ace1 whereas Bgace2 is to the insect ace2. Transcript level of Bgace1 was significantly higher (c. 10 fold) than that of Bgace2 in all 11 tissues examined, suggesting that Bgace1 likely encodes a predominant AChE. Multiple AChE bands were identified by native polyacrylamide gel electrophoresis and isoelectricfocusing from various tissue preparations, among which ganglia produced distinct two major and two minor AChE bands, indicative of the presence of at least two active AChEs. B. germanica AChEs appeared to be mainly localized in the central nervous system as demonstrated by histochemical activity staining, together with quantitative analysis of Bgace transcripts. Fluorescence in situ hybridization of the 1st thoracic ganglion confirmed that Bgace1 is predominantly transcribed and further showed that its transcript is found in almost entire region of inter or motor neurones including the cell bodies and axonal/dendritic branches. Bgace2 transcript is found only in the subset of neurones, particularly in the cell body. In addition, certain neurones were observed to express Bgace1 only.

DLG differentially localizes Shaker K+-channels in the central nervous system and retina of Drosophila.

Subcellular localization of ion channels is crucial for the transmission of electrical signals in the nervous system. Here we show that Discs-Large (DLG), a member of the MAGUK (membrane-associated guanylate kinases) family in Drosophila, co-localizes with Shaker potassium channels (Sh Kch) in most synaptic areas of the adult brain and in the outer membrane of photoreceptors. However, DLG is absent from axonal tracts in which Sh channels are concentrated. Truncation of the C-terminal of Sh (including the PDZ binding site) disturbs its pattern of distribution in both CNS and retina, while truncation of the guanylate kinase/C-terminal domain of DLG induces ectopic localization of these channels to neuronal somata in the CNS, but does not alter the distribution of channels in photoreceptors. Immunocytochemical, membrane fractionation and detergent solubilization analysis indicate that the C-terminal of Sh Kch is required for proper trafficking to its final destination. Thus, several major conclusions emerge from this study. First, DLG plays a major role in the localization of Sh channels in the CNS and retina. Second, localization of DLG in photoreceptors but not in the CNS seems to depend on its interaction with Sh. Third, the guanylate kinase/C-terminal domain of DLG is involved in the trafficking of Shaker channels but not of DLG in the CNS. Fourth, different mechanisms for the localization of Sh Kch operate in different cell types.

Optimization of fed-batch fermentation for xylitol production by Candida tropicalis.

Xylitol, a functional sweetener, was produced from xylose by biological conversion using Candida tropicalis ATCC 13803. Based on a two-substrate fermentation using glucose for cell growth and xylose for xylitol production, fed-batch fermentations were undertaken to increase the final xylitol concentration. The effects of xylose and xylitol on xylitol production rate were studied to determine the optimum concentrations for fed-batch fermentation. Xylose concentration in the medium (100 g l(-1)) and less than 200 g l(-1) total xylose plus xylitol concentration were determined as optimum for maximum xylitol production rate and xylitol yield. Increasing the concentrations of xylose and xylitol decreased the rate and yield of xylitol production and the specific cell growth rate, probably because of an increase in osmotic stress that would interfere with xylose transport, xylitol flux to secretion to cell metabolism. The feeding rate of xylose solution during the fed-batch mode of operation was determined by using the mass balance equations and kinetic parameters involved in the equations in order to increase final xylitol concentration without affecting xylitol and productivity. The optimized fed-batch fermentation resulted in 187 g l(-1) xylitol concentration, 0.75 g xylitol g xylose(-1) xylitol yield and 3.9 g xylitol l(-1) h(-1) volumetric productivity.

Health promotion programme in the private workplaces in Singapore: a prevalence survey.

A postal survey was conducted in 4,479 private companies with at least 50 employees in 1998 to determine the prevalence and the scope of workplace health promotion programme in these companies in Singapore. The self-administered questionnaire mailed to the study population covered five areas viz, organisational details, workplace health policies, health promotion and related activities, workplace health facilities and the source of assistance for the programme. The overall response was 49.5%. Parkinson's definition of workplace health promotion was used in the analysis to determine the prevalence of the programme. The data was collated on DBase IV and analysed using SPSS computer programmes. About one third of the respondents covering an estimated 26% of the private sector workforce had a comprehensive workplace health promotion programme as defined by Parkinson. This prevalence was a function of workforce size and industry type. Workplaces with larger workforce size (p<0.001) and those from the manufacturing and human/health service sectors (p<0.001) were more likely to have such programmes compared to their smaller counterparts and other industries respectively. The management remained the main driver behind these programmes. Many of the programmes were centred around health promoting policies and facilities with emphasis on occupational healthl safety and smoking issues. A significant proportion of workplaces surveyed had in place a comprehensive workplace health promotion programme. However, more could still be done to encourage its uptake such as training for facilitators, consultation, grant provision etc. Small workplaces remained an untapped market for such programmes.

Osmotic stress induces HB-EGF gene expression via Ca(2+)/Pyk2/JNK signal cascades in rat aortic smooth muscle cells.

The present study was undertaken in an attempt to clarify the pathway by which hyperosmotic stress induces HB-EGF gene expression in rat aortic smooth muscle cells (RASMC). Hyperosmotic stress induced by a high concentration of glucose or mannitol resulted in an increase in HB-EGF mRNA level in a dose- and time-dependent manner. HB-EGF induction was blocked by curcumin, a c-jun/fos antisense oligonucleotide and a dominant-negative mutant of JNK1. Electrophoretic mobility shift assay also showed the involvement of AP-1 in HB-EGF gene expression by glucose. In addition, hyperosmotic stress induced rapid phosphorylation of Pyk2 in RASMC. TPA and calcium chelating agents (BAPTA-AM and EGTA) blocked Pyk2 phosphorylation and HB-EGF gene expression. Furthermore, HB-EGF gene expression and JNK activation by hyperosmotic stress were sensitive to PP2, an Src kinase-specific inhibitor. These findings indicate that hyperosmotic stress activates JNK via calcium-Pyk2 signaling cascades, which in turn induce HB-EGF gene expression.

Liver abscess after transcatheter oily chemoembolization for hepatic tumors: incidence, predisposing factors, and clinical outcome.

PURPOSE: To evaluate the incidence of, predisposing factors for, and clinical outcome of liver abscess developing in patients with hepatic tumors after transcatheter oily chemoembolization (TOCE). MATERIALS AND METHODS: During the past 6-year period, 2,439 patients with hepatic tumors underwent a total of 6,255 TOCE procedures. With a retrospective review of medical records, the authors evaluated the occurrence of liver abscess, the statistical significance of potential predisposing factors including portal vein obstruction, metastatic tumors, biliary abnormalities (type 1, simple biliary obstruction; type 2, status prone to ascending biliary infection), malignant gastrointestinal mucosal lesions, and additional gelatin sponge particle embolization in liver abscess formation, and the clinical outcome of abscess. RESULTS: Fifteen liver abscesses occurred in 14 patients (0.2%). Liver abscesses developed in three of 987 (0.3%) TOCE procedures for portal vein obstruction, three of 114 (2.6%) procedures for metastatic tumors, one of 49 (1.8%) for type 1 biliary abnormality, four of 55 (7.4%) for type 2 biliary abnormality, two of 18 (11.1%) for malignant gastrointestinal mucosal lesion, and nine of 2,108 (0.4%) for additional gelatin sponge particle embolization. Univariate and multivariate statistical analysis showed that type 2 biliary abnormality was a significant predisposing factor. The mortality related to liver abscess occurred in two patients (13.3%). Thirteen liver abscesses were successfully treated with parenteral antibiotics and percutaneous catheter drainage. However, irreversible deterioration of liver function occurred in two patients. Two of nine further TOCE procedures in three patients caused recurrent septicemia and liver abscess. CONCLUSION: The biliary abnormality prone to ascending biliary infection was the most important predisposing factor to the development of liver abscess after TOCE. Postembolic liver abscess could be effectively managed with percutaneous catheter drainage.

Effects of nicotinamide coenzymes on the stability of enzyme activities and proteins in niacin-deficient quail tissues against trypsin treatment.

The stability of liver and muscle enzymes and proteins in niacin-deficient quail towards trypsin treatment in the presence and absence of coenzymes, NAD or NADP, was characterized. The protection of liver dehydrogenases by coenzymes was low when they are subjected to trypsin digestion for 60 min. In contrast, in the muscle there was substantial protection against trypsin inactivation of glyceraldehyde-3-phosphate dehydrogenase by NAD and of 6-phosphogluconate dehydrogenase by NADP. Among all enzymes tested, glyceraldehyde-3-phosphate dehydrogenase showed the greatest protection against trypsin inactivation by NAD. SDS-polyacrylamide gel electrophoresis demonstrated that muscle proteins from the niacin-deficient group were more substantially protected compared to control and pair-fed groups when liver and muscle extracts were spiked with NAD and subjected to trypsin digestion. Overall results suggest that niacin deficiency exerted specific destabilizing effects on the stability of enzymes and proteins in muscle.

US of mammographically detected clustered microcalcifications.

PURPOSE: To determine whether ultrasonography (US) can depict breast masses associated with mammographically detected clustered microcalcifications and whether the visibility at US is different between benign and malignant lesions. MATERIALS AND METHODS: Ninety-four patients with 100 mammographically detected microcalcification clusters prospectively underwent US with a 10- or 12-MHz transducer before mammographically guided presurgical hook-wire localization. The visibility of breast masses at US was correlated with histologic and mammographic findings. RESULTS: Surgical biopsy revealed 62 benign lesions, 30 intraductal cancers, and eight invasive cancers. At US, breast masses associated with microcalcifications were seen in 45 (45%) of 100 cases. US depicted more breast masses associated with malignant (31 [82%] of 38) than with benign (14 [23%] of 62) microcalcifications (P: <.001). In malignant microcalcification clusters larger than 10 mm, US depicted associated breast masses in all 25 cases. There was no statistically significant difference in shape and distribution of calcific particles, as well as in breast composition, at mammography between US visible and invisible groups. CONCLUSION: Given a known mammographic location, US with a high-frequency transducer can depict breast masses associated with malignant microcalcifications, particularly clusters larger than 10 mm. US can be used to visualize large clusters of microcalcifications that have a very high suspicion of malignancy.

Synaptic targeting and localization of discs-large is a stepwise process controlled by different domains of the protein.

BACKGROUND: Membrane-associated guanylate kinases (MAGUKs) assemble ion channels, cell-adhesion molecules and components of second messenger cascades into synapses, and are therefore potentially important for co-ordinating synaptic strength and structure. Here, we have examined the targeting of the Drosophila MAGUK Discs-large (DLG) to larval neuromuscular junctions. RESULTS: During development, DLG was first found associated with the muscle subcortical compartment and plasma membrane, and later was recruited to the postsynaptic membrane. Using a transgenic approach, we studied how mutations in various domains of the DLGprotein affect DLG targeting. Deletion of the HOOK region-the region between the Src homology 3 (SH3) domain and the guanylate-kinase-like (GUK) domain-prevented association of DLG with the subcortical network and rendered the protein largely diffuse. Loss of the first two PDZ domains led to the formation of large clusters throughout the plasma membrane, with scant targeting to the neuromuscular junction. Proper trafficking of DLG missing the GUK domain depended on the presence of endogenous DLG. CONCLUSIONS: Postsynaptic targeting of DLG requires a HOOK-dependent association with extrasynaptic compartments, and interactions mediated by the first two PDZ domains. The GUK domain routes DLG between compartments, possibly by interacting with recently identified cytoskeletal-binding partners.

Dynamic contrast-enhanced MR imaging of bacterial abscess and VX2 carcinoma in rabbits: comparison of gadopentetate dimeglumine and a macromolecular contrast agent.

OBJECTIVE: The objective of this study was to compare enhancement patterns of a blood-pool contrast agent, Gadomer-17, with those of gadopentetate dimeglumine in bacterial abscesses and VX2 carcinoma in rabbits. MATERIALS AND METHODS: Fourteen rabbits with experimentally induced bacterial abscesses and VX2 carcinoma in both thighs underwent dynamic contrast-enhanced MR imaging with Gadomer-17 and gadopentetate dimeglumine at a 24-hr interval. The enhancement ratios (postcontrast to precontrast signal intensities) of lesions in the same animal were assessed and correlated with microvessel density. RESULTS: For Gadomer-17, the enhancement ratio of the abscesses (1.66 +/- 0.39) peaked 15 min after the injection, while that of the carcinoma (2.05 +/- 0.16) peaked at 10 min. The enhancement ratios of the carcinoma were consistently higher than those of the abscesses up to 30 min. For gadopentetate dimeglumine, peak enhancement ratio of the abscesses (2.30 +/- 0.75) was seen 5 min after the injection, while that of the carcinoma (2.32 +/- 0.51) was seen at 3 min. The enhancement ratios of the carcinomas were significantly higher at 1 min, but significantly lower at 20-30 min, compared with those of the abscesses, as a result of rapid decrease of enhancement ratios in the carcinomas. The microvessel density was 9.8 +/- 5.2 vessels per field of view for the abscesses and 36.3 +/- 9.5 vessels per field of view for the carcinoma (p < 0.001). CONCLUSION: Delayed peak enhancement and slow decay were found in both bacterial abscess and VX2 carcinoma with Gadomer-17, whereas early peak enhancement and rapid decay were found especially in VX2 carcinoma with gadopentetate dimeglumine. Enhancement ratios on MR imaging with a blood-pool contrast agent correlated well with the microvessel density in bacterial abscess and VX2 carcinoma.

Drosophila larval neuromuscular junction: molecular components and mechanisms underlying synaptic plasticity.

Understanding the mechanisms that mediate synaptic plasticity is a primary goal of molecular neuroscience. The Drosophila larval neuromuscular junction provides a particularly useful model for investigating the roles of synaptic components in both structural and functional plasticity. The powerful molecular genetics of this system makes it possible to uncover new synaptic components and signaling molecules, as well as their function in the intact organism. Together with the mouse hippocampus and Aplysia dissociated cell culture, the Drosophila larval neuromuscular junction has been among the most valuable model systems for examining the molecular and cellular basis of neuronal plasticity.

MR imaging features of clear-cell meningioma with diffuse leptomeningeal seeding.

Clear-cell meningioma is a rare disease entity showing a more aggressive nature, clinically, than those of other subtypes of meningioma. It occurs in younger persons and commonly in the spinal canal. The recurrence rate has been reported to be as high as 60%. We present a case of clear-cell meningioma in a 17-year-old man in whom initial MR imaging showed localized leptomeningeal enhancement that had progressed into the entire subarachnoid space after surgical resection of the primary tumor.

Aldehyde reductase gene expression by lipid peroxidation end products, MDA and HNE.

Membrane lipid peroxidation results in the production of a variety of aldehydic compounds that play a significant role in aging, drug toxicity and the pathogenesis of a number of human diseases, such as atherosclerosis and cancer. Increased lipid peroxidation and reduced antioxidant status may also contribute to the development of diabetic complications. This study reports that lipid peroxidation end products such as malondialdehyde (MDA) and 4-hydroxynonenal (HNE) induce aldehyde reductase (ALR) gene expression. MDA and HNE induce an increase in intracellular peroxide levels; N-Acetyl-L-cysteine (NAC) suppressed MDA- and HNE-induced ALR gene expression. These results indicate that increased levels of intracellular peroxides by MDA and HNE might be involved in the upregulation of ALR.

Copper, zinc superoxide dismutase enhances DNA damage and mutagenicity induced by cysteine/iron.

Oxidative DNA damage caused by a cysteine metal-catalyzed oxidation system (Cys-MCO) comprised of Fe(3+), O(2), and a cysteine as an electron donor was enhanced by copper, zinc superoxide dismutase (CuZnSOD) in a concentration-dependent manner, as reflected by the formation of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) and strand breaks. Unlike CuZnSOD, manganese SOD (MnSOD) as well as iron SOD (FeSOD) did not enhance DNA damage. The capacity of CuZnSOD to enhance damage to DNA was inhibited by a spin-trapping agent, 5, 5-dimethyl-1-pyrroline N-oxide (DMPO) and a metal chelator, diethylenetriaminepentaacetic acid (DETAPAC). The deoxyribose assay showed that hydroxyl free radicals were generated in the reaction of CuZnSOD with Cys-MCO. We found that the Cys-MCO system caused the release of free copper from CuZnSOD. CuZnSOD also caused the two-fold enhancement of a mutation in the pUC18 lacZ' gene in the presence of Cys-MCO when measured as a loss of alpha-complementation. Based on these results, we interpret the effects of CuZnSOD on Cys-MCO-induced DNA damage and mutation as due to reactive oxygen species, probably hydroxyl free radicals, formed by the reaction of free Cu(2+), released from oxidatively damaged CuZnSOD, and H(2)O(2) produced by the Cys-MCO system.

Regulation of DLG localization at synapses by CaMKII-dependent phosphorylation.

Discs large (DLG) mediates the clustering of synaptic molecules. Here we demonstrate that synaptic localization of DLG itself is regulated by CaMKII. We show that DLG and CaMKII colocalize at synapses and exist in the same protein complex. Constitutively activated CaMKII phenocopied structural abnormalities of dlg mutant synapses and dramatically increased extrajunctional DLG. Decreased CaMKII activity caused opposite alterations. In vitro, CaMKII phosphorylated a DLG fragment with a stoichiometry close to one. Moreover, expression of site-directed dlg mutants that blocked or mimicked phosphorylation had effects similar to those observed upon inhibiting or constitutively activating CaMKII. We propose that CaMKII-dependent DLG phosphorylation regulates the association of DLG with the synaptic complex during development and plasticity, thus providing a link between synaptic activity and structure.