Characterization of hindlimb motoneuron membrane properties in acute and chronic spinal cats

The purpose of this study was to determine if changes in hindlimb motoneuron membrane electrical properties occur 4–6 months after spinal transection in the adult animal. Eight acute and nine chronic animals were spinalized at T₁₂. Intracellular recordings from motoneurons innervating the triceps surae were performed. Membrane electrical properties, including resting potential, action potential peak amplitude, afterhyperpolarization duration, rheobasic current, input resistance and axonal conduction velocity were measured. There were no statistical differences found between group means or frequency distributions in the membrane properties of motoneurons assessed from acute and chronic spinal animals. Thus, alteration of motoneuron membrane properties does not appear to be a major contributing factor to the hyperexcitable hindlimb reflex activity demonstrated by chronic spinal animals.     

Nucleotide Sequence of the ADH23 Gene Encoding the Human Alcohol Dehydrogenase β3 Subunit

All nine exons of the ADH2(3) allele, which encodes the human alcohol dehydrogenase beta 3 subunit, have been cloned and sequenced. Comparison of this sequence to the ADH2(1) nucleotide sequence revealed only a single difference that results in an amino acid change, thus proving that the significant kinetic differences between these two isozymes is due to the Cys for Arg substitution at position 369. There are also two silent polymorphisms, and two changes in noncoding regions.     

A procedure for purifying low-abundance protein components from the brain cytoskeleton-nuclear matrix fraction

We describe a preparative procedure for low-abundance proteins of the cytoskeleton-nuclear matrix fraction from frozen bovine brain. Strigent centrifugation and washing conditions in the preparation of the cytoskeleton-nuclear matrix fraction are avoided to minimize loss of nuclear material. A recently described horizontal isoelectric focusing column, which tolerates appreciable precipitation, is used. In concert with selection of urea concentration and temperature, this isoelectric focusing apparatus provides a new approach to the fractionation of this complex, relatively insoluble mixture of proteins and other components. In addition, a heated, sodium dodecyl sulfate-sizing column has been utilized in order to eliminate interactions between the desired low abundance proteins and more abundant contaminating proteins. Together these procedures purify a specific low-abundance protein sufficiently to be detected by Coomassie blue staining in two-dimensional gels. The methods are robust and can be applied to multiple, relatively large brain samples (150 g of crude grey matter per batch); thus they should facilitate partial peptide sequencing for brain proteins of this operational class.     

Carcinoma of the papilla of vater: Are endoscopic appearance and endoscopic biopsy discordant?

Carcinoma of the papilla of Vater is classified as periampullary cancer representing 5% of all gastrointestinal tract malignancies. Early and accurate diagnosis is important for those patients with a tumor of the papilla, as the prognosis is more favorable than in other periampullary neoplasms. Endoscopically obtained biopsies from suspicious papillae can detect an early tumor, although even for skilled pathologists it is often difficult to differentiate carcinomas from noninvasive lesions on the basis of forceps biopsies. The purpose of this study was to assess the preoperative diagnostic accuracy of duodenoscopy appearance and biopsy in all cases with suspicion of tumor. Thirty patients with suspicion of carcinoma of the papilla of Vater and with final diagnosis established by pancreatoduodenectomy were included in this retrospective study. In each case, a comparison was made between endoscopic biopsy and duodenoscopic appearance. Duodenoscopic appearance sensitivity and accuracy for malignancy were 86% and 83%, respectively, whereas endoscopic biopsy sensitivity and accuracy were 65% and 67%, respectively. Although preoperative diagnosis of carcinoma of the papilla of Vater is useful for making therapeutic decisions, the diagnostic value of the endoscopic appearance was superior to endoscopic biopsy in this series. Presented at the 2003 American Hepato-Pancreato-Biliary Association Congress, Miami, Florida, February 27-March 3, 2003. Supported by FADA-CAPES/PROP 200J (M.L.D.).     

Emphysema induced by elastase enhances acute inflammatory pulmonary response to intraperitoneal LPS in rats

Abnormalities in lungs caused by emphysema might alter their response to sepsis and the occurrence of acute lung injury (ALI). This study compared the extension of ALI in response to intraperitoneal lipopolysaccharide (LPS) injection in Wistar rats with and without emphysema induced by elastase. Adult male Wistar rats were randomized into four groups: control, emphysema without sepsis, normal lung with sepsis and emphysema with sepsis. Sepsis was induced, and 24 h later the rats were euthanised. The following analysis was performed: blood gas measurements, bronchoalveolar lavage (BAL), lung permeability and histology. Animals that received LPS showed significant increase in a lung injury scoring system, inflammatory cells in bronchoalveolar lavage (BAL) and IL‐6, TNF‐α and CXCL2 mRNA expression in lung tissue. Animals with emphysema and sepsis showed increased alveolocapillary membrane permeability, demonstrated by higher BAL/serum albumin ratio. In conclusion, the presence of emphysema induced by elastase increases the inflammatory response in the lungs to a systemic stimulus, represented in this model by the intraperitoneal injection of LPS.