Ubiquitin carboxy-terminal hydrolase L1 (UCHL1) S18Y polymorphism in Alzheimer's disease

Alzheimer's disease (AD) is characterized by protein aggregates, i.e. senile plaques and neurofibrillary tangles. The ubiquitin-proteasome system has been proposed a role in proteolytic removal of these protein aggregates. Ubiquitin carboxy-terminal hydrolase L1 (UCHL1) is a de-ubiquitinating enzyme with important functions in recycling of ubiquitin. The S18Y polymorphism of the UCHL1 gene confers protection against Parkinson's disease. In this study, the genotype and allele frequencies of the UCHL1 S18Y polymorphism were investigated in 452 AD patients and 234 control subjects, recruited from four memory clinics in Sweden. Using a binary logistic regression model including UCHL1 allele A and APOE ε4 allele positivity, age and sex as covariates with AD diagnosis as dependent variable, an adjusted OR of 0.82 ([95% CI 0.55-1.24], P = 0.35) was obtained for a positive UCHL1 allele A carrier status. The present study thus do not support a protective effect of the UCHL1 S18Y polymorphism against AD.     

Purification of branched chain aminotransferase from rat heart mitochondria

This paper presents the first purification of the branched chain aminotransferase (EC 2.6.1.42) from rat heart mitochondria. The enzyme has been purified from the 100,000 x g supernatant obtained after sonication and ultracentrifugation of rat heart mitochondria. A combination of open column chromatography, high pressure liquid chromatography (HPLC), and discontinuous polyacrylamide disc gel electrophoresis was used. The key step in the procedure was hydrophobic interaction chromatography on HPLC. The final purification step was polyacrylamide disc gel electrophoresis where the enzyme appeared as a doublet. When electroeluted from the gel, each of these bands had the same specific activity demonstrating that there are two forms of the purified enzyme which differ slightly in electrical charge. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, these two enzyme forms appeared as a single band with a molecular mass of 43 kDa. Size exclusion chromatography on Sephacryl S-100 identified the enzyme as a 50-kDa protein. These experiments argue against the existence of a dimeric form of this enzyme. The ratio of enzyme activity with leucine (0.84), valine (0.88), or glutamate (0.66) as amino acid substrate versus isoleucine remained constant throughout the purification procedure. Specific activity of the final preparation was 66 units/mg of enzyme protein. Polyclonal antibodies against the purified enzyme were raised in rabbits. On an immunoblot the antiserum recognized a 43-kDa protein in the 100,000 x g supernatant from a rat heart mitochondrial sonicate but did not recognize any proteins in rat brain cytosol. Quantitative immunodot assay resulted in an estimated enzyme content of about 100 micrograms of branched chain aminotransferase protein/g of heart, wet weight. Finally, 97% of the heart branched chain aminotransferase activity could be neutralized by the antiserum, but the antiserum would not neutralize aminotransferase activity in brain cytosol. These data suggest that close sequence homology does not exist between the two proteins.     

Different HLA DR-DQ associations in subgroups of idiopathic myasthenia gravis

We have investigated theHLA-DRB and -DQB gene polymorphism in 131 myasthenia gravis (MG) patients. TheHLA genotypes in these patients were assigned by means of restriction fragment length polymorphism (RFLP)-definedDR-DQ haplotypes, correlating to serologic HLA class II typing. Using this technique we could, among randomly selected non-thymomatous (NT)-MG patients, confirm the strong association to DR3, and 70% of the patients were found to carry a specific DR3-positiveDR-DQ haplotype,T-3.1. Furthermore, an analysis of T-3.1^– NT-MG patients revealed that 59 % were T-4.1^÷ (DR4, DQw8). Thymic hyperplasia was found in approximately 85 % of the T-3.1⁺ , as well as of the T-4.1⁺ /3.1^– patients. As previously observed, we found a clear dominance of females among the T-3.1⁺ NT-MG patients. However, among T-4.1⁺/3.1- patients, males were as common as females. Furthermore, the T-4.1⁺ patients were significantly older at the onset of disease than those who were T-3.1⁺. In female MG patients, the DRwl5-Dw2-positive haplotypeT-2.1 was strongly correlated with the presence of thymoma (T-MG). These data indicate that the HLA associations in early vs late onset of NT-MG are different, and that female patients with and without thymoma differ from each other with regard to HLA markers. Thus, at least three different HLA DR-DQ associations are found in subgroups of idiopathic MG.     

Interaction of estramustine phosphate with microtubule-associated proteins

We have reported [(1984) Cancer Res., in press] that estramustine phosphate inhibits microtubule assembly and disassembled preformed microtubules. We now present evidence that estramustine phosphate inhibits microtubule assembly by binding to the microtubule-associated proteins. We have found that: additional microtubule-associated proteins relieved the inhibition of assembly by estramustine phosphate; 3H-labelled estramustine phosphate bound predominantly to the microtubule-associated proteins; and the content of the microtubule-associated proteins was reduced in taxol reversed estramustine phosphate-inhibited microtubules.     

Improved yield of apple leaf protoplasts from in vitro cultured shoots by using very young leaves and adding L-methionine to the shoot medium

Protoplast isolation from apple leaf tissue of in-vitro cultured shoots is possible if very young leaves from buds are used. Digestible leaves are found in apple shoots of the subculture kerö 14 days after transferring the shoot and of M26 some days later.The yield of protoplasts is considerably improved if the apple shoots are cultured in a medium containing L-methionine (0.5 mM).     

A simplified procedure for preparation of undecalcified human bone sections

A new type of apparatus for sectioning samples of hard, undecalcified bone is described. Slices of fresh or archeological human bone 4-5 mm thick are dehydrated and then embedded in epoxy resin. The apparatus used to prepare sections from the resulting blocks consists of a low-speed rim-type diamond cut-off wheel and a slowly advancing table carrying the specimen held in a rotating mount. Sections may be cut at a thickness of 80 micron +/- 1%. After cleaning in an ultrasonic bath, these can be mounted on slides for quantitative microscopic examination with transmitted light. Grinding and polishing are not necessary. The results obtained are illustrated.     

The influence of ozone on the stomatal and non-stomatal limitation of photosynthesis in Norway spruce,Picea abies (L.) Karst,exposed to soil moisture deficit

Summary Norway spruce, Picea abies (L.) Karst., was exposed to charcoal-filtered air (CF) and non-filtered air + ozone (NF+) and periods of soil moisture deficit from 1985 to 1988 in open-top chambers. Net photosynthesis, stomatal conductance, needle water potential and various shoot properties were measured on 1-year-old shoots during a period of soil moisture deficit. The gas exchange was measured at saturating photosynthetic photon flux density and across a range of CO₂ concentrations. The soil moisture deficit induced a mild drought stress in the plants, expressed by a pre-dawn needle water potential of approximately-0.9 MPa and a substantial reduction in net photosynthesis and gas phase conductance. In the CF treatment, intercellular CO₂ concentration was reduced, but was unaffected in the NF+ treatment. Furthermore, net photosynthesis declined more in response to the soil moisture deficit in the NF+ treatment than in the CF treatment. This is suggested to be attributed to the carboxylation efficiency at the operating point, which was decreased by 47% and 64% in shoots from the CF and the NF+ treatments, respectively. Stomatal limitation of net photosynthesis was increased by drought by 24–45% in the CF treatment, while it was unaffected in the NF+ treatment. Thus, our results imply that the coupling between the stomatal conductance and the photosynthetic rate was changed and that the marginal cost of water per given amount of carbon gain will increase in trees exposed to ozone, during periods of drought.     

The influence of different age classes on the seasonal activity and reproduction of four medium-sized carabid species inhabiting cereal fields

Reproduction and survival of four carabid species commonly occurring in cereal fields in central Sweden were investigated. The adult-overwintering Pterostichus cupreus L. bred in early summer (June), and the largest proportion of sexually active beetles were found to be in their first breeding year; only a minority were 2 (or more) years old. In contrast, the larval-overwintering P. melanarius Illiger, P. niger Schaller and Harpalus rufipes De Geer had a biennal life cycle, and mainly old beetles (2 years or older) contributed to the population's reproductive effort each year. The long prereproductive adult phase in the larval-overwintering species and the relatively short summer in central Sweden prevented many new-generation adults from breeding in their first year. Several overlapping breeding cohorts are therefore present each year, and overwintered beetles bred throughout summer and during part of the autumn. Mandible wear (combined with other characters) was used to determine the age of beetles. However, the rate of mandible wear also was found to vary, depending upon the extent to which each species burrowed in the ground. The ecological significance of (a) a long adult life and (b) the existence of several overlapping breeding cohorts for reproduction and survival of populations in cereal fields is discussed.     

A suggested relationship between sugar beet leaf spot and upper—air flow patterns

The flow pattern of the upper air at the 500 mb level was found to be the key to the surface weather pattern influencing the development of CERCOSPORA BETICOLA on sugar beet. Stable long-wave conditions of the upper air provided more persistent surface conditions unfavorable for leaf spot development. A train of short wave produced favorable weather conditions for leaf spot development.

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Zusammenfassung Es wurde nachgewiesen, dass die Strömungsformen der oberen Luftschichten auf dem 500 mb Niveau die Wetterformen an der Oberfläche beeinflussen, die die Entwicklung von CERCOSPORA BETICOLA auf Zuckerrüben erklären. Stabile Langwellen-Bedingungen in den oberen Luftschichten bedingen gleichmässigere Oberflächenbedingungen, die für die Blattflecken ungünstig sind, während eine Folge kurzer Wellen zu Wetterbedingungen führt, die für die Blattfleckenbildung günstig sind.

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Resume On a pu démontrer que la forme de l'écoulement de l'air au niveau de 500 mb se répercute sur les conditions atmosphériques au sol, conditions particulières qui agissent sur le développement de CERCOSPORA BETICOLA de la betterave à sucre. Des conditions stables d'écoulement ne présentant que de larges ondulations dans les couches supérieures de l'atmosphère provoquent des conditions de surface défavorables au développement de la maladie. Au contraire, une succession de courtes ondulations conduit à des conditions de surface favorables au champignon.

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Journal Paper No. J-6610 of the Iowa Agriculture and Home Economics Experiment Station, Project 1163. Cooperative investigation of the Iowa Station and Crops Research Division, Agricultural Research Division, United States Department of Agriculture.     

Water Permeability in Resting and Stimulated Crayfish Nerve

The hydraulic conductivity, L_p, was determined in single axons of the crayfish, Procambarus clarkii, by injecting a hypertonic sample between two drops of silicone oil and photographing the volume increase of the sample. The method has the advantage of minimizing errors due to hydrostatic pressure differences across the membrane. In resting axons an L_p of 0.236 x 10^-8 cm/ sec per cm H₂O was found and similar values were obtained with low external calcium concentration and when the nerve was continuously stimulated at 20–30 impulses/sec. Thus the experiments have failed to demonstrate any change of water permeability in cases in which the ionic conductance is known to change. Some possible implications of this are discussed.