Postural dysregulation in systolic blood pressure is associated with worsened scoring on neurobehavioral function tests and leukoaraiosis in the older elderly living in a community

BACKGROUND AND PURPOSE: Postural hypotension, which occurs frequently in community-living, apparently healthy elderly adults, is usually asymptomatic. However, the relation between postural changes in blood pressure and quantitative higher cerebral function or silent brain lesions remains unclear. We examined the association of exaggerated postural changes in systolic blood pressure with cognitive and quantitative neurobehavioral functions and with brain lesions on MRI in the community-dwelling older elderly. METHODS: The study population consisted of 334 community-dwelling elderly adults, aged 75 years or older (mean age, 80 years). Postural changes in systolic blood pressure (SBP) were assessed using an autosphygmomanometer (BP-203 I). By the difference between the mean of two measurements of SBP at standing and at supine position (dSBP = SBP at upright-SBP at supine position), we divided the subjects into three groups: (1) 20 subjects with postural hypotension (d-SBP < or = -20 mm Hg), (2) 29 subjects with postural hypertension (dSBP > or = 20 mm Hg), and (3) 285 subjects with postural normotension (20 < dSBP < 20 mm Hg). We defined the former two groups as the postural dysregulation group. Scores in four neurobehavioral function tests (Mini-Mental State Exam. Hasegawa Dementia Scale Revised, computer-assisted visuospatial cognitive performance score, and the Up and Go Test) and activities of daily living were compared among the three groups. Brain lesions on MRI, including number of lacunes and periventricular hyperintense lesions, were compared among 15 age- and sex-matched control subjects with postural hypotension, 15 with postural hypertension, and 30 with postural normotension. RESULTS: Twenty subjects (6.0%) exhibited postural hypotension and 29 (8.7%) postural hypertension. Scores in neurobehavioral functions and activities of daily living were significantly lower in the postural dysregulation group (both postural hypotension and hypertension groups) than in the postural normotension group. The postural dysregulation group exhibited significantly more advanced periventricular hyperintensities than the normotension group. CONCLUSIONS: Asymptomatic community dwelling elderly individuals with postural hypotension as well as those with postural hypertension had poorer scores on neurobehavioral function tests and more advanced leukoaraiosis demonstrated on MRI than those without exaggerated postural changes in SBP.     

Selective hydrogenation and isomerization of pentadiene over molybdenum hexacarbonyl encaged in a NaY zeolite

Highly stereo-selective hydrogenation of trans-1,3-pentadiene to cis-2-pentene and isomerization of 1,4-pentadiene to cis-1,3-pentadiene were found to take place thermally at 423 K over Mo(CO)₆/NaY. Relative hydrogenation rates of pentadiene isomers indicated that s-cis conformation of diene was crucial for the selective hydrogenation to occur. This was substantiated by an IR study.     

Congenital mediastinal bronchogenic cyst with malignant transformation: an autopsy report

A rare autopsy case of mediastinal bronchogenic cyst with malignant transformation is presented. The cyst had been located in the anterior mediastinum for at least 28 years in a 52 year old male. Chest X-ray findings showing rapid enlargement of the cyst and biopsy of the spine for lumbago made a clinical diagnosis as suspicious mediastinal cystic teratoma with malignant transformation metastasizing to the spine. Postmortem examination revealed that the cyst was located in the anterior mediastinum extending to the left pulmonary hilum and had no connection with the tracheobronchial tree. The cyst wall consisted of bronchus-like tissue including ciliated epithelium, hyaline cartilage, smooth muscle and mucoserous glands. There were no teratomatous components in the wall. Malignant tumor predominantly consisting of round cells occurred in the thickened cyst wall and grew into the cyst cavity with direct invasion of the lung and metastases to the liver, adrenal glands, bone marrow of the lumbar spine and lymph nodes. An immunohistochemical study showed that the tumor cells frequently expressed cytokeratin, epithelial membrane antigen and carcino-embryonic antigen, occasionally CA19-9, vimentin and neuron-specific enolase. From these findings, the tumor was diagnosed as undifferentiated carcinoma arising in the mediastinal bronchogenic cyst.     

A Biomimetic Approach to Taxol: Stereoselective Synthesis of a 12-Membered Ring Ene-Epoxide

The stereoselective synthesis of a taxol intermediate via a biomimetic route is described. Aldol condensation of γ-butyrolactone and citral derivatives generated three stereogenic centers at positions C1, C2, and C11 corresponding to taxol. Intramolecular alkylation of the cyanohydrin ether efficiently formed the 12-membered ring system in which stereoselective reduction, followed by directed epoxidation, afforded the key intermediate epoxide.     

Stress corrosion cracking of type 304 austenitic stainless steel in sulphuric acid solution including sodium chloride and chromate

The stress corrosion cracking (SCC) of a commercial austenitic stainless steel type 304 was investigated as functions of chloride concentration, chromate concentration and test temperature under a constant applied stress condition in 0.82 kmol/m³ sulphuric acid solution by using a constant load method. From the dependence of the three parameters (, steady state elongation rate; t_ss, transition time; t_f, time to failure) obtained from corrosion elongation curve on chloride/chromate concentrations and test temperature, a parameter for predicting time to failure and critical values of chromate concentration and test temperature, below which little SCC takes place, were estimated. In addition, a transgranular SCC mechanism was qualitatively inferred and then the effect of chromate and chloride on SCC behavior was discussed.     

In vivo directed evolution for thermostabilization of Escherichia coli hygromycin B phosphotransferase and the use of the gene as a selection marker in the host-vector system of Thermus thermophilus

An in vivo-directed evolutionary strategy was used to obtain a thermostabilized Escherichia coli hygromycin B phosphotransferase, using a host-vector system of Thermus thermophilus. Introduction of the mutant gene containing two amino acid substitutions, S52T and W238C, which was previously reported by Cannio et al. [J. Bacteriol., 180, 3237-3240 (1998)], did not confer hygromycin resistance on T. thermophilus cells at 55 degrees C; however, five spontaneously-generated independent mutants were obtained by selection of the transformants at this temperature. Each mutant gene contained one amino acid substitution of either A118V or T246A. Further selection with increasing temperature, at 58 degrees C and then 61 degrees C, led to acquisition of three more substitutions: D20G, S225P and Q226L. These mutations cumulatively influenced the maximum growth temperature of the T. thermophilus transformants in the presence of hygromycin; T. thermophilus carrying a mutant gene containing all the five substitutions was able to grow at up to 67 degrees C. This mutant gene, hph5, proved useful as a selection marker in the T. thermophilus host-vector system, either on the plasmid or by genome integration, at temperatures up to 65 degrees C.     

Effect of glycated collagen on proliferation of human smooth muscle cells in vitro

While non-enzymatic glycation of long-lived tissue proteins such as collagen has been implicated in chronic complications of diabetes mellitus, its role in the aetiology of diabetic macroangiopathy has not been elucidated. To test the hypothesis that glycation of collagen abolishes the inhibitory effect of native collagen on the proliferation of human smooth muscle cells, we obtained smooth muscle cells from human gastric arteries and cultured them on dishes coated with glycated or non-glycated collagen. The proliferation of human smooth muscle cells in the presence of 10% fetal calf serum or platelet derived growth factor-BB (10 ng/ml) was inhibited by type 1 collagen coated on the dishes. Glycation of collagen with glucose 6-phosphate for 7 days abolished the growth-inhibitory effect of native collagen. Succinylation of collagen, which like glycation blocked the lysyl residues in collagen, also abolished the growth-inhibitory effect. Adhesion of human smooth muscle cells to collagen-coated dishes was not affected by glycation of collagen. Addition of glycated albumin to the medium did not affect the growth of human smooth muscle cells on plastic dishes. The inhibition of human smooth muscle cell proliferation by collagen was not reversed by the glycation of collagen in the presence of aminoguanidine. Results suggest that early glycation abolishes the inhibitory effect of collagen on human smooth muscle cell proliferation and may thus participate in the progression of macro-angiopathy in diabetes.     

Spatiochromatic receptive field properties derived from information-theoretic analyses of cone mosaic responses to natural scenes

Neurons in the early stages of processing in the primate visual system efficiently encode natural scenes. In previous studies of the chromatic properties of natural images, the inputs were sampled on a regular array, with complete color information at every location. However, in the retina cone photoreceptors with different spectral sensitivities are arranged in a mosaic. We used an unsupervised neural network model to analyze the statistical structure of retinal cone mosaic responses to calibrated color natural images. The second-order statistical dependencies derived from the covariance matrix of the sensory signals were removed in the first stage of processing. These decorrelating filters were similar to type I receptive fields in parvo- or konio-cellular LGN in both spatial and chromatic characteristics. In the subsequent stage, the decorrelated signals were linearly transformed to make the output as statistically independent as possible, using independent component analysis. The independent component filters showed luminance selectivity with simple-cell-like receptive fields, or had strong color selectivity with large, often double-opponent, receptive fields, both of which were found in the primary visual cortex (V1). These results show that the "form" and "color" channels of the early visual system can be derived from the statistics of sensory signals.     

Whole sequence of spoIIIE-like, sporulation-inhibitory, and transfer gene (spi) in a conjugative plasmid, pSA1.1, of Streptomyces azureus and detection of spi-like gene in the actinomycete chromosome

The nucleotide sequence of spoIIIE-like and the sporulation-inhibitory and transfer gene (spi) in a conjugative plasmid, pSA1.1, of Streptomyces azureus were examined to detect the promoter region. Using Southern blotting and a spi fragment as probe, spi-like genes were detected in chromosomes of the host and other actinomycetes. These results suggest that there is a spi- and spoIIIE-like gene in chromosomes of some actinomycetes.