Auditory testing profiles of Pelizaeus-Merzbacher disease.

To characterize the auditory manifestations of patients diagnosed with Pelizaeus-Merzbacher Disease (PMD), a rare X-linked disorder of myelin classically characterized by nystagmus, spastic quadriparesis, ataxia, and cognitive delay in early childhood or progressive disease in adulthood. A prospective case study of 5 pediatric and 3 adult patients diagnosed with PMD who demonstrate varying degrees of abnormal auditory function. These patients underwent comprehensive audiological evaluations (audiometry, tympanometry, otoacoustic emissions), auditory processing tests (Dichotic Listening, Frequency Pattern Test, Duration Pattern Test), and electrophysiological measures (Auditory Brainstem Response). Abnormal electrophysiological findings with normal cochlear function were found in all test subjects. Further testing completed on adult subjects revealed further central auditory dysfunction via auditory processing tests. All the adult test subjects had abnormal results on auditory processing tests including significant left ear deficits on dichotic digits and poor duration pattern test scores. Auditory processing test results indicated strong right ear advantages for all adult PMD test subjects in Dichotic Digit testing. The degree of audiological central dysfunction findings was more severe in subjects with greater symptoms of the disease. Our findings indicate the need for a full audiological test battery on all patients with Pelizaeus-Merzbacher disease and other severe neurological disorders.

Low-dose indomethacin after ischemic acute kidney injury prevents downregulation of Oat1/3 and improves renal outcome.

We have previously shown that expression of renal organic anion transporters Oat1 and Oat3 is diminished by prostaglandin E(2) (PGE(2)) and that both transporters are downregulated after renal ischemia. Because PGE(2) is increased after renal ischemia and is generated by cyclooxygenases (COX), we investigated the effect of the COX inhibitor indomethacin on expression of Oat1/3 after ischemic acute kidney injury (iAKI). iAKI was induced in rats by bilateral clamping of renal arteries for 45 min. Indomethacin (1 mg/kg) was given intraperitoneally as soon as reperfusion started. Sham-treated animals served as controls. Oat1/3 were determined by qPCR and Western blot. PGE(2) in blood and urine was measured by enzyme-linked immunosorbent assay. Invasion of monocytes/macrophages was determined. Glomerular filtration rate and renal plasma flow were determined. All parameters were detected 24 h after ischemia. PAH net secretion, as well as clearance and secretion of PGE(2) were calculated. In clamped animals, indomethacin restored expression of Oat1/3, as well as PAH net secretion, PGE(2) clearance, or PGE(2) secretion. Additionally, indomethacin substantially improved kidney function as measured by glomerular filtration and PAH clearance. Indomethacin did not affect ischemia-induced invasion of monocytes/macrophages. In conclusion, our study indicates that low-dose indomethacin applied after ischemia prevents ischemia-induced downregulation of Oat1/3 during reperfusion and has a substantial protective effect on kidney function after iAKI. The beneficial effect of low-dose indomethacin on renal outcome is likely due to an effect different from inhibition of inflammation. In accordance to the decreased PAH net secretion, renal excretion of an endogenous organic anion (PGE(2)) is also impaired after ischemia and reperfusion.

Study rationale and design of the CIMT trial: the Copenhagen Insulin and Metformin Therapy trial.

BACKGROUND: Patients with type 2 diabetes (T2DM) have an increased mortality rate primarily because of macrovascular disease. Where T2DM patients cannot be managed sufficiently through diet, exercise and peroral antidiabetic drugs, that is when haemoglobin A1c (HbA1c) is above 7.0%, it is yet unknown whether a combination of metformin and insulin analogues is superior to insulin analogues alone. Nor is it known which insulin analogue regimen is the optimal. OBJECTIVE: The primary objective of this trial is to evaluate the effect of an 18-month treatment with metformin vs. placebo in combination with one of three insulin analogue regimens, the primary outcome measure being carotid intima-media thickness (CIMT) in T2DM patients. DESIGN: A randomized, stratified, multicentre trial having a 2 x 3 factorial design. The metformin part is double masked and placebo controlled. The insulin treatment is open. The intervention period is 18 months. PATIENT POPULATION: Nine hundred and fifty patients with T2DM and HbA1c > or = 7.5% on treatment with oral hypoglycaemic agents or on insulin treatment and deemed able, by the investigator, to manage once-daily insulin therapy with a long-acting insulin analogue. RANDOMIZATION: Central randomization stratified for age (above 65 years), previous insulin treatment and treatment centre. INTERVENTIONS: Metformin 1 g x two times daily vs. placebo (approximately 475 patients vs. 475 patients) in combination with insulin detemir before bedtime (approximately 315 patients) or biphasic insulin aspart 30 before dinner with the possibility to increase to two or three injections daily (approximately 315 patients) or insulin aspart before the main meals (three times daily) and insulin detemir before bedtime (approximately 315 patients). Intervention follows a treat-to-target principle in all six arms aiming for an HbA1c < or = 7.0%. OUTCOME MEASURES: Primary outcome measure is the change in CIMT from baseline to 18 months. Secondary outcome measures comprises the composite outcome of death, acute myocardial infarction, stroke or amputation assessed by an adjudication committee blinded to intervention, other cardiovascular clinical outcomes, average postprandial glucose increment from 0 to 18 months, hypoglycaemia and any inadvertent medical episodes. In addition, change in plaque formation in the carotids, HbA1c, cardiovascular biomarkers, body composition, progression of microvascular complications and quality of life will be assessed as tertiary outcome measures. TIME SCHEDULE: Patient enrolment started May 2008. Follow-up is expected to finish in March 2011. CONCLUSION: CIMT is designed to provide evidence as to whether metformin is advantageous even during insulin treatment and to provide evidence regarding which insulin analogue regimen is most advantageous with regard to cardiovascular disease.

An ion source research facility.

As an ion source developer, D-Pace frequently faces the issue of needing access to a research facility to be able to test equipment or to develop our existing technology further. The closest facility to perform such tasks is hundreds of kilometers away, at TRIUMF, and it is not always feasible to make use of it on a timely basis. With a growing demand and a desire to enhance our products, the idea to create an ion source research facility in our region evolved. In this paper, we will discuss the approach that was chosen to reach our goal, the status of the project, the principle layout of the facility, and the different ways this facility could be utilized.

In vitro effects of soy phytoestrogens on rat L6 skeletal muscle cells.

Soy isoflavones display estrogenic activity in humans and animals, and thus are referred to as phytoestrogens. This study was performed to observe the effects of the soy isoflavones genistein, daidzein, and glycitein on cell cultures of rat skeletal muscles. [3H]Thymidine incorporation was used to determine cell proliferation, while protein synthesis and degradation were determined by tracking radiolabeled leucine. For the proliferation studies, insulin, estradiol, genistein, daidzein, or glycitein was supplemented at 0, 0.04, 0.08, 0.16, 0.31, 0.63, 1.25, 2.5, 5, 10, or 20 microM, respectively, or in combinations with final concentrations of 0, 0.1, 1, or 10 microM. Genistein reacted most similarly to estradiol, inhibiting proliferation at > or = 1 microM (P < .001). A combination of phytoestrogens resulted in significant inhibition of cell proliferation, but not to the extent observed with genistein alone. For the protein synthesis and degradation experiments, treatments of 0.1 microM dexamethasone or 1 microM concentrations of insulin, genistein, daidzein, or glycitein were used. Phytoestrogens did not inhibit or stimulate protein degradation or synthesis (P > .05). A one-tailed univariate analysis of variance revealed a trend (P < or = .1) in protein stimulation with genistein and glycitein treatments. These results suggest that the tyrosine kinase inhibiting activity of genistein may be affecting phosphorylation of the mitosis-promoting factor, preventing the advancement of the mitotic cell cycle. In addition, at higher total combined concentrations, daidzein and glycitein may be able to outcompete genistein for receptor sites. These results suggest that soy isoflavones in the diet may potentially modulate normal growth and development in humans and animals that ingest soy-based products.

Pharmacokinetics of levetiracetam and its enantiomer (R)-alpha-ethyl-2-oxo-pyrrolidine acetamide in dogs.

PURPOSE: The new antiepileptic drug, levetiracetam (LEV, ucb LO59), is a chiral molecule with one asymmetric carbon atom whose anticonvulsant activity is highly enantioselective. The purpose of this study was to evaluate and compare the pharmacokinetics (PK) of LEV [(S)-alpha-ethyl-2-oxo-pyrrolidine acetamide] and its enantiomer (R)-alpha-ethyl-2-oxo-pyrrolidine acetamide (REV) after i.v. administration to dogs. This is the first time that the pharmacokinetics of both enantiomers has been evaluated. METHODS: Optically pure LEV and REV were synthesized, and 20 mg/kg of individual enantiomers was administered intravenously to six dogs. Plasma and urine samples were collected until 24 h, and the concentrations of LEV and REV were determined by an enantioselective assay. The levels of 2-pyrrolidone-N-butyric acid, an acid metabolite of LEV and REV, were determined by high-performance liquid chromatography (HPLC). The data were used for PK analysis of LEV and REV. RESULTS: LEV and REV had similar mean +/- SD values for clearance; 1.5 +/- 0.3 ml/min/kg and volume of distribution; 0.5 +/- 0.1 L/kg. The half-life (t1/2) and mean residence time (MRT) of REV (t1/2, 4.3 +/- 0.8 h, and MRT, 6.0 +/- 1.1 h) were, however, significantly longer than those of LEV (t1/2, 3.6 +/- 0.8 h, and MRT, 5.0 +/- 1.2 h). The renal clearance and fraction excreted unchanged for LEV and REV were significantly different. CONCLUSIONS: In addition to the enantioselective pharmacodynamics, alpha-ethyl-2-oxo-pyrrolidine acetamide has enantioselective PK. The enantioselectivity was observed in renal clearance. Because REV has more favorable PK in dogs than LEV, the higher antiepileptic potency of LEV is more likely due to intrinsic pharmacodynamic activity rather than to enantioselective PK.

Interactions in postweaning production of F1 cattle from Hereford, Limousin, or Piedmontese sires.

A 2-yr study was conducted to evaluate the interactions of castration, feeding length, and dietary CP on growth and carcass characteristics of male cattle (bulls and steers) that vary in expression of muscular hypertrophy. Crossbred cows were bred by AI to Hereford, Limousin, or Piedmontese bulls, which represented genotypes with normal, moderate, and hypermuscularity, respectively, but with similar mature weights. Male calves (131 in yr 1 and 120 in yr 2) were placed in pens with individual electronic feeding gates. Calves were fed growing diets until they reached 386 kg BW and then were individually switched to finishing diets for 90 or 132 d. Interactions were observed among sire breed, gender, and feeding length on carcass composition. Bulls were more efficient than steers in producing live weight gain. Length of finishing period accounted for a larger source of variation than gender for weight characteristics, whereas gender was the larger source of variation for carcass composition. Concentration or degradability of dietary CP influenced rate of gain from weaning to 386 kg. Interactions resulting from varying management on carcass characteristics among calves of different sire breeds indicate that unique strategies may be beneficial for the production of meat from these breeds.

DNA-Directed expression of functional flock house virus RNA1 derivatives in Saccharomyces cerevisiae, heterologous gene expression, and selective effects on subgenomic mRNA synthesis.

Flock house virus (FHV), a positive-strand RNA animal virus, is the only higher eukaryotic virus shown to undergo complete replication in yeast, culminating in production of infectious virions. To facilitate studies of viral and host functions in FHV replication in Saccharomyces cerevisiae, yeast DNA plasmids were constructed to inducibly express wild-type FHV RNA1 in vivo. Subsequent translation of FHV replicase protein A initiated robust RNA1 replication, amplifying RNA1 to levels approaching those of rRNA, as in FHV-infected animal cells. The RNA1-derived subgenomic mRNA, RNA3, accumulated to even higher levels of >100,000 copies per yeast cell, compared to 10 copies or less per cell for 95% of yeast mRNAs. The time course of RNA1 replication and RNA3 synthesis in induced yeast paralleled that in yeast transfected with natural FHV virion RNA. As in animal cells, RNA1 replication and RNA3 synthesis depended on FHV RNA replicase protein A and 3'-terminal RNA1 sequences but not viral protein B2. Additional plasmids were engineered to inducibly express RNA1 derivatives with insertions of the green fluorescent protein (GFP) gene in subgenomic RNA3. These RNA1 derivatives were replicated, synthesized RNA3, and expressed GFP when provided FHV polymerase in either cis or trans, providing the first demonstration of reporter gene expression from FHV subgenomic RNA. Unexpectedly, fusing GFP to the protein A C terminus selectively inhibited production of positive- and negative-strand subgenomic RNA3 but not genomic RNA1 replication. Moreover, changing the first nucleotide of the subgenomic mRNA from G to T selectively inhibited production of positive-strand but not negative-strand RNA3, suggesting that synthesis of negative-strand subgenomic RNA3 may precede synthesis of positive-strand RNA3.

Separation and absolute configuration of the enantiomers of a degradation product of the new inhalation anesthetic sevoflurane.

In a rebreathing anesthesia circuit, the inhaled anesthetic sevoflurane degrades into at least two products, termed "compound A" and "compound B." The enantiomer separation of the chiral compound B (1,1,1,3,3-pentafluoro-2-(fluoromethoxy)-3-methoxypropane ) by capillary gas chromatography (cGC) using heptakis (2,3-di-O-acetyl-6-O-tert-butyldimethylsilyl)-beta-cyclodextrin as chiral selector was studied. With this cyclodextrin derivative diluted in the polysiloxane PS 86, an unprecedented high separation factor alpha of 4.1 (at 30 degrees C) was found. Consequently, the enantiomers of compound B were isolated by preparative GC and their specific rotations were measured. In addition, their absolute configurations were determined by X-ray crystallography. To collect the X-ray data, single crystals of both enantiomers were grown in situ on the diffractometer. The levorotatory enantiomer B(-) has the R-configuration while the dextrorotatory enantiomer B(+) has the S-configuration. The elution order of the compound B enantiomers on heptakis (2,3-di-O-acetyl-6-O-tert-butyldimethylsilyl)-beta-cyclodextrin is R before S.

Enantioselective analysis of levetiracetam and its enantiomer R-alpha-ethyl-2-oxo-pyrrolidine acetamide using gas chromatography and ion trap mass spectrometric detection.

A gas chromatographic-mass spectrometric method was developed for the enantioselective analysis of levetiracetam and its enantiomer (R)-alpha-ethyl-2-oxo-pyrrolidine acetamide in dog plasma and urine. A solid-phase extraction procedure was followed by gas chromatographic separation of the enantiomers on a chiral cyclodextrin capillary column and detection using ion trap mass spectrometry. The fragmentation pattern of the enantiomers was further investigated using tandem mass spectrometry. For quantitative analysis three single ions were selected from the enantiomers, enabling selected ion monitoring in detection. The calibration curves were linear from 1 microM to 2 mM for plasma samples and from 0.5 mM to 38 mM for urine samples. In plasma and urine samples the inter-day precision, expressed as relative standard deviation was around 10% in all concentrations. Selected ion monitoring mass spectrometry is suitable for quantitative analysis of a wide concentration range of levetiracetam and its enantiomer in biological samples. The method was successfully applied to a pharmacokinetic study of levetiracetam and (R)-alpha-ethyl-2-oxo-pyrrolidine acetamide in a dog.

Effects of training on maximum oxygen consumption of ponies.

OBJECTIVES: To establish maximum oxygen consumption VO2max) in ponies of different body weights, characterize the effects of training of short duration on VO2max, and compare these effects to those of similarly trained Thoroughbreds. ANIMALS: 5 small ponies, 4 mid-sized ponies, and 6 Thoroughbreds. PROCEDURE: All horses were trained for 4 weeks. Horses were trained every other day for 10 minutes on a 10% incline at a combination of speeds equated with 40, 60, 80, and 100% of VO2max. At the beginning and end of the training program, each horse performed a standard incremental exercise test in which VO2max was determined. Cardiac output (Q), stroke volume (SV), and arteriovenous oxygen content difference (C [a-v] O2) were measured in the 2 groups of ponies but not in the Thoroughbreds. RESULTS: Prior to training, mean VO2max for each group was 82.6 = 2.9, 97.4 +/- 13.2, and 130.6 +/- 10.4 ml/kg/min, respectively. Following training, mean VO2max increased to 92.3 +/- 6.0, 107.8 +/- 12.8, and 142.9 +/- 10.7 ml/kg/min. Improvement in VO2max was significant in all 3 groups. For the 2 groups of ponies, this improvement was mediated by an increase in Q; this variable was not measured in the Thoroughbreds. Body weight decreased significantly in the Thoroughbreds but not in the ponies. CONCLUSIONS AND CLINICAL RELEVANCE: Ponies have a lower VO2max than Thoroughbreds, and larger ponies have a greater VO2max than smaller ponies. Although mass-specific VO2max changed similarly in all groups, response to training may have differed between Thoroughbreds and ponies, because there were different effects on body weight.

Stereoselective pharmacokinetics and pharmacodynamics of propylisopropyl acetamide, a CNS-active chiral amide analog of valproic acid.

PURPOSE: The purpose of this study was to evaluate there existed stereoselective effects in the pharmacokinetics, anticonvulsant activity, microsomal epoxide hydrolase (mEH) inhibition, and teratogenicity of the two enantiomers of propylisopropyl acetamide (PID), a CNS-active chiral amide analogue of valproic acid. METHODS: Racemic PID, as well as the individual enantiomers, were intravenously administered to six dogs in order to investigate the stereoselectivity in their pharmacokinetics. Anticonvulsant activity was evaluated in mice (ip) and rats (oral), mEH inhibition studies were performed in human liver microsomes, and teratogenicity was evaluated in an inbred susceptible mice strain. RESULTS: Following intravenous administration to dogs of the individual enantiomers, (R)-PID had significantly lower clearance and longer half-life than (S)-PID, however, the volumes of distribution were similar. In contrast, following intravenous administration of racemic PID, both enantiomers had similar pharmacokinetic parameters. In rats (oral), (R)-PID had a significantly lower ED50 in the maximal electroshock seizure test than (S)-PID; 16 and 25 mg/kg, respectively. PID enantiomers were non-teratogenic and did not demonstrate stereoselective mEH inhibition. CONCLUSIONS: (R)-PID demonstrated better anticonvulsant activity, lower clearance and a longer half-life compared to (S)-PID. When racemic PID was administered, the clearance of (S)-PID was significantly reduced, reflecting an enantiomer-enantiomer interaction.

Enantiomer separation by pressure-supported electrochromatography using capillaries packed with a permethyl-beta-cyclodextrin stationary.

Efficient enantiomer separation by pressure-assisted, micro-packed capillary electrochromatography (CEC) has been carried out using a permethyl-beta-cyclodextrin-modified silica support (PM-beta-CD-silica). When comparing this method with micro-packed-high-performance liquid chromatography in the single-column-mode, CEC displays higher column efficiencies (about three times higher theoretical plate numbers at comparable elution times). The pressure support (about 10 bar), applied to avoid bubble formation, has a negligible influence on elution times in CEC. The influence of the type and composition of organic modifiers is described.

Structural analysis of a bovine arginine tRNA(CCG) gene.

A bovine genomic clone containing a 17.4-kb DNA fragment was isolated and found to contain a solitary arginine tRNA gene with an anticodon of CCG that has a 100% identity to its cognate tRNA. This arginine tRNA gene, symbolized as TRR4, has a characteristic internal split promoter and a typical termination site for RNA polymerase III. The tRNA gene was transcribed in vitro by RNA polymerase III using a HeLa cell-free extract to yield a mature-sized tRNA product. The gene was mapped to bovine chromosome 19 using a panel of bovine-rodent somatic cell hybrid DNAs.

Ruptured spinal dermoid cyst with chemical arachnoiditis and disseminated intracranial lipid droplets.

A 33-year-old man presented with a 3-month history of gradually progressive leg weakness. Spinal MRI and myelography with CT demonstrated an extensive intradural abnormality suggesting a diffuse inflammatory or neoplastic process. Only after cranial CT and MRI demonstrated lipid droplets was the diagnosis of a ruptured spinal dermoid cyst suggested. Subsequent laminectomy revealed a ruptured intradural dermoid cyst in the lumbar spine, with chemical arachnoiditis.

Subependymoma of filum terminale: MR appearance.

This report describes a subependymoma of the filum terminale evaluated by MRI. The mass demonstrated hyperintense signal on conventional spin echo T1-weighted, proton density, and T2-weighted imaging and nonenhancement after intravenous gadolinium administration. These characteristics distinguish this lesion from other more common neoplastic and inflammatory lesions arising in the lumbar spinal canal that are typically isointense on T1-weighted spin echo acquisitions, hyperintense on T2-weighted imaging, and enhance variably after intravenous gadolinium administration.

MRI of benign lumbosacral nerve root enhancement.

Enhancement of nerve roots in the lumbosacral spine after intravenous administration of gadolinium contrast agents is seen in benign conditions such as disc herniation and spinal stenosis and may be observed in either the unoperated or postoperative spine. Correlating reasonably well with the clinical syndrome, nerve root enhancement represents actual pathology within nerve roots reflected by this breakdown in the blood-nerve barrier. Nerve root enhancement may be used in certain circumstances to show and confirm clinically relevant neurological disease.

Genetic and physical mapping of the patatin genes in potato and tomato.

Genes for the major storage protein of potato, patatin, have been mapped genetically and physically in both the potato and tomato genomes. In potato, all patatin genes detected by the cDNA clone pGM01 map to a single locus at the end of the long arm of chromosome 8. By means of pulsed field gel electrophoresis (PFGE) it was possible further to delimit this locus, containing 10-15 copies of the gene, to a maximum size of 1.4 million base pairs. Hybridizations with class-specific clones suggest that the locus is at least partially divided into domains containing the two major types of patatin genes, class I and II. In tomato, patatin-homologous sequences were found to reside at the orthologous locus at the end of chromosome 8. The approximately three copies in tomato were localized by PFGE to a single fragment of 300 kilobases. Whereas the class II-specific 5' promoter sequences reside in tomato at the same locus as the coding sequences, the single class I-specific copy of the 5' promoter sequences was localized on chromosome 3 with no coding sequence attached to it. A clone from this chromosome 3 locus of tomato was isolated and by restriction fragment length polymorphism mapping it could be further shown that a similar class I-specific sequence also exists on chromosome 3 of potato. As in tomato, this copy on chromosome 3 is not linked to a coding sequence for patatin. The results are discussed with respect to genome evolution and PFGE analysis of complex gene families.

Secretin-dependent HCO3- secretion from pancreas and liver.

Ultrastructural studies performed on pigs revealed that numerous cytoplasmic tubulovesicles were present in resting pancreatic duct cells. Elevation of systemic arterial PCO2 from 5.5 to 11 kPa increased the number of vesicles more than twofold. Following secretin administration, concurrent with the onset of HCO3- secretion (JHCO3), the cytoplasm became devoid of vesicles, and the basolateral plasma membrane surface area more than doubled. Similar phenomena were observed in bile duct cells. After pretreatment with the microtubules-inhibiting drug colchicine, secretin failed to reduce duct cell vesicle density, and JHCO3 was reduced by c. 50% compared to the control. These ultrastructural changes resemble those described in other H+/HCO3(-)-transporting organs such as the distal nephron and the urinary bladder. Our findings are compatible with the notion that cytoplasmic vesicles containing H(+)-ATPases are incorporated into the basolateral plasma membrane of secretory cells during secretin stimulation. Active transport of H+ into interstitial fluid might therefore be the driving force underlying JHCO3.

Effect of parathyroid hormone on elastase release from human polymorphonuclear leucocytes.

Acute and chronic renal failure are clinical states associated with secondary hyperparathyroidism and increased catabolism. It has been suggested that elevated proteolytic activity is present in the blood in these clinical states. It is, theoretically, possible that the excess blood levels of parathyroid hormone (PTH) in patients with these disorders stimulate release of proteases, since this latter process is calcium dependent and PTH enhances entry of calcium into cells. The present study examined the effect of PTH and its amino- and carboxyterminal fragments on elastase release from polymorphonuclear leucocytes (PMNL), and evaluated the mechanisms underlying such an action. 1-84 PTH stimulated elastase release from PMNL in a dose-dependent and time-dependent manner. This effect of the hormone was abolished by its inactivation as well as by the presence of EDTA. Verapamil, trifluoperazine and W-7 reduced but did not abolish the 1-84 PTH-induced stimulation of elastase release from PMNL. Phorbol ester (PMA) also stimulated elastase release but both PTH or PMA-induced elastase release was blunted by staurosporin, an inhibitor of protein kinase C. The 19-84 carboxyterminal PTH also produced significant stimulation of elastase release from PMNL but the amino-terminal 1-34 PTH or other peptide hormones (insulin, calcitonin, and ACTH) had no stimulatory effect on elastase release.(ABSTRACT TRUNCATED AT 250 WORDS)