A rescue factor abolishing neuronal cell death by a wide spectrum of familial Alzheimer's disease genes and Abeta

Through functional expression screening, we identified a gene, designated Humanin (HN) cDNA, which encodes a short polypeptide and abolishes death of neuronal cells caused by multiple different types of familial Alzheimer's disease genes and by Abeta amyloid, without effect on death by Q79 or superoxide dismutase-1 mutants. Transfected HN cDNA was transcribed to the corresponding polypeptide and then was secreted into the cultured medium. The rescue action clearly depended on the primary structure of HN. This polypeptide would serve as a molecular clue for the development of new therapeutics for Alzheimer's disease targeting neuroprotection.

Left ventricular midwall mechanics in systemic arterial hypertension. Myocardial function is depressed in pressure-overload hypertrophy

BACKGROUND

Left ventricular (LV) midwall geometry has been described conventionally as the sum of the chamber radius and half of the wall thickness; this convention is based on the assumption of uniform transmural thickening during systole. However, theoretical considerations and experimental data indicate that the inner half (inner shell) of the LV wall thickens more than the outer half (outer shell). Thus, an end-diastolic circumferential midwall fiber exhibits a relative migration toward the epicardium during systole. As a result, the conventional method provides an overestimate of the extent of the midwall fiber shortening.

METHODS AND RESULTS

We developed an ellipsoidal model with a concentric two-shell geometry (nonuniform thickening) to assess midwall fiber length transients throughout the cardiac cycle. This modified midwall method was used in the analysis of LV cineangiograms from 15 patients with systemic arterial hypertension and 14 normal subjects. Study groups were classified according to LV mass index (LVMI): 14 normal subjects (group I), eight hypertensive patients with a normal LVMI (group II), and seven hypertensive patients with an increased LVMI (group III). There were no significant differences in LV end-diastolic pressure or volume among the three groups; the ejection fraction was slightly greater in group II (70 +/- 5%) than in groups I (65 +/- 8%) and III (66 +/- 4%), but this trend did not achieve statistical significance. Values for endocardial and conventional midwall fractional shortening (FS) were also similar in the three groups. By contrast, FS by the concentric two-shell geometry (modified midwall method) in group III (16 +/- 2%) was significantly less than that seen in groups I and II (21 +/- 4% and 21 +/- 5%, respectively; both p less than 0.05). This difference achieves greater importance when it is recognized that mean systolic circumferential stress was lower in group III (151 +/- 22 g/cm2) than in groups I and II (244 +/- 37 g/cm2 and 213 +/- 38 g/cm2, respectively; both p less than 0.01). The midwall stress-shortening coordinates in six of the seven group III patients were outside the 95% confidence limits for the normal (group I) subjects. Thus, despite a normal ejection fraction, systolic function is subnormal in hypertensive patients with LV hypertrophy.

CONCLUSIONS

Chamber dynamics provide an overestimate of myocardial function, especially when LV wall thickness is increased. This is due to a relatively greater contribution of inner shell thickening in pressure-overload hypertrophy.

Contribution of the surface free energy perturbation to protein-solvent interactions

Surface tension measurements were carried out at 20 degrees C by a capillary drop-weight method on aqueous solutions of sodium glutamate (NaGlu), lysine hydrochloride (LysHCl), potassium aspartate (KAsp), arginine hydrochloride (ArgHCl), lysylglutamate (LysGlu), argininylglutamate (ArgGlu), guanidinium sulfate, trehalose, trimethylamine N-oxide (TMAO), dimethyl sulfoxide, 2-methyl-2,4-pentanediol (hexylene glycol), and poly(ethylene glycol)s of molecular weights 200, 400, 600, and 1000. All of the salts and the sugar increased the surface tension of water, while the last four compounds decreased it, with 2-methyl-2,4-pentanediol lowering it most effectively and TMAO being the least effective. The preferential hydration of bovine serum albumin (BSA) and lysozyme was measured in KAsp, ArgHCl, LysGlu, and ArgGlu. The high values of preferential hydration found in all cases, except for BSA in ArgHCl, suggest that they should stabilize protein structure, as had been found for lysine hydrochloride and monosodium glutamate [Arakawa, T., & Timasheff, S. N. (1984) J. Biol. Chem. 259, 4979-4986]. A correlation was found for both BSA and lysozyme in KAsp, NaGlu, LysHCl, ArgGlu, and LysGlu between the surface tension effect and the observed preferential interactions, indicating that the change in the surface free energy of the protein-containing cavity due to the surface tension increase for water by these amino acid salts contributes dominantly to the observed increase in the chemical potential of the protein by their addition. The lack of a correlation observed for BSA, but not lysozyme, in ArgHCl at low concentrations where preferential binding is close to zero suggests, however, that the surface tension effect is not the sole factor involved in the protein-solvent interactions in these amino acid salts. Binding of ArgHCl to BSA, probably through hydrogen bonds between the Arg guanidinium group and peptide bonds, was proposed to occur, the affinity of Arg+ being reduced by electrostatic repulsion when proteins carry a net positive charge, such as is the case with lysozyme. Since the four organic solvent additives also lead to protein preferential hydration, no correlation exists between their preferential interactions and the surface free energy perturbation. Therefore, in their case, the preferential hydration must be ascribed to other factors that overcome the preferential binding expected from the Gibbs adsorption isotherm. The surface tension results, however, are consistent with the binding of the organic solvents to proteins through hydrophobic interactions, explaining, at least in part, the observed concentration dependence of the interactions.

Japanese men have larger areas of visceral adipose tissue than Caucasian men in the same levels of waist circumference in a population-based study

Visceral adipose tissue (VAT) is an independent risk factor for metabolic and cardiovascular disorders. There has been no study that demonstrated different abdominal fat distribution between Asian and Caucasian men. As the Japanese are less obese but more susceptible to metabolic disorders than Caucasians, they may have larger VAT than Caucasians at similar levels of obesity. We compared the abdominal fat distribution of the Japanese (n=239) and Caucasian-American (n=177) men aged 40-49 years in groups stratified by waist circumference in a population-based sample. We obtained computed tomography images and determined areas of VAT and subcutaneous adipose tissue (SAT). We calculated VAT to SAT ratio (VSR). The Japanese men had a larger VAT and VSR in each stratum, despite substantially less obesity overall. In multiethnic studies, difference in abdominal fat distribution should be considered in exploring factors related to obesity.

Sex-specific relevance of diabetes to occlusive vascular and other mortality: a collaborative meta-analysis of individual data from 980 793 adults from 68 prospective studies

BACKGROUND

Several studies have shown that diabetes confers a higher relative risk of vascular mortality among women than among men, but whether this increased relative risk in women exists across age groups and within defined levels of other risk factors is uncertain. We aimed to determine whether differences in established risk factors, such as blood pressure, BMI, smoking, and cholesterol, explain the higher relative risks of vascular mortality among women than among men.

METHODS

In our meta-analysis, we obtained individual participant-level data from studies included in the Prospective Studies Collaboration and the Asia Pacific Cohort Studies Collaboration that had obtained baseline information on age, sex, diabetes, total cholesterol, blood pressure, tobacco use, height, and weight. Data on causes of death were obtained from medical death certificates. We used Cox regression models to assess the relevance of diabetes (any type) to occlusive vascular mortality (ischaemic heart disease, ischaemic stroke, or other atherosclerotic deaths) by age, sex, and other major vascular risk factors, and to assess whether the associations of blood pressure, total cholesterol, and body-mass index (BMI) to occlusive vascular mortality are modified by diabetes.

RESULTS

Individual participant-level data were analysed from 980 793 adults. During 9·8 million person-years of follow-up, among participants aged between 35 and 89 years, 19 686 (25·6%) of 76 965 deaths were attributed to occlusive vascular disease. After controlling for major vascular risk factors, diabetes roughly doubled occlusive vascular mortality risk among men (death rate ratio [RR] 2·10, 95% CI 1·97-2·24) and tripled risk among women (3·00, 2·71-3·33; χ2 test for heterogeneity p<0·0001). For both sexes combined, the occlusive vascular death RRs were higher in younger individuals (aged 35-59 years: 2·60, 2·30-2·94) than in older individuals (aged 70-89 years: 2·01, 1·85-2·19; p=0·0001 for trend across age groups), and, across age groups, the death RRs were higher among women than among men. Therefore, women aged 35-59 years had the highest death RR across all age and sex groups (5·55, 4·15-7·44). However, since underlying confounder-adjusted occlusive vascular mortality rates at any age were higher in men than in women, the adjusted absolute excess occlusive vascular mortality associated with diabetes was similar for men and women. At ages 35-59 years, the excess absolute risk was 0·05% (95% CI 0·03-0·07) per year in women compared with 0·08% (0·05-0·10) per year in men; the corresponding excess at ages 70-89 years was 1·08% (0·84-1·32) per year in women and 0·91% (0·77-1·05) per year in men. Total cholesterol, blood pressure, and BMI each showed continuous log-linear associations with occlusive vascular mortality that were similar among individuals with and without diabetes across both sexes.

INTERPRETATION

Independent of other major vascular risk factors, diabetes substantially increased vascular risk in both men and women. Lifestyle changes to reduce smoking and obesity and use of cost-effective drugs that target major vascular risks (eg, statins and antihypertensive drugs) are important in both men and women with diabetes, but might not reduce the relative excess risk of occlusive vascular disease in women with diabetes, which remains unexplained.

FUNDING

UK Medical Research Council, British Heart Foundation, Cancer Research UK, European Union BIOMED programme, and National Institute on Aging (US National Institutes of Health).

Biotechnology applications of amino acids in protein purification and formulations

Amino acids are widely used in biotechnology applications. Since amino acids are natural compounds, they can be safely used in pharmaceutical applications, e.g., as a solvent additive for protein purification and as an excipient for protein formulations. At high concentrations, certain amino acids are found to raise intra-cellular osmotic pressure and adjust to the high salt concentrations of the surrounding medium. They are called "compatible solutes", since they do not affect macromolecular function. Not only are they needed to increase the osmotic pressure, they are known to increase the stability of the proteins. Sucrose, glycerol and certain amino acids were used to enhance the stability of unstable proteins after isolation from natural environments. The mechanism of the action of these protein-stabilizing amino acids is relatively well understood. On the contrary, arginine was accidentally discovered as a useful reagent for assisting in the refolding of recombinant proteins. This effect of arginine was ascribed to its ability to suppress aggregation of the proteins during refolding, thereby increasing refolding efficiency. By the same mechanism, arginine now finds much wider applications than previously anticipated in the research and development of proteins, in particular in pharmaceutical applications. For example, arginine solubilizes proteins from loose inclusion bodies, resulting in efficient production of active proteins. Arginine suppresses protein-protein interactions in solution and also non-specific adsorption to gel permeation chromatography columns. Arginine facilitates elution of bound proteins from various column resins, including Protein-A or dye affinity columns and hydrophobic interaction columns. This review covers various biotechnology applications of amino acids, in particular arginine.

Protein--solvent interactions in pharmaceutical formulations

The stability of proteins is affected by a variety of solvent additives. Sugars, certain amino acids and salts, and polyhydric alcohols stabilize proteins in solution and during freeze-thawing. Urea and guanidine hydrochloride destabilize proteins under either condition. These effects can be explained from the preferential interactions of the cosolvents with the proteins; i.e., the protein stabilizers are preferentially excluded from the proteins, while the destabilizers bind to them. There is a class of compounds, such as polyethylene glycol and 2-methyl-2,4-pentanediol, that destabilize proteins at high temperature but stabilize them during freeze-thawing. Such effects can be accounted for by their preferential exclusion from the native proteins determined at room temperature and from their hydrophobic character, which depends on temperature. During freeze-drying, only a few sugars appear to be effective in protecting proteins from inactivation, as most other stabilizers cannot exert their action on proteins without water. The stabilization is due to hydrogen bonding between the sugars and the dried proteins, the sugars acting as water substitute. Understanding the mechanism of the effects of solvent additives on the protein stability should aid in the development of a suitable formulation for protein.

What cause of mortality can we predict by cholesterol screening in the Japanese general population?

OBJECTIVE

In a population with a markedly lower coronary mortality such as in Japan, the benefit of cholesterol screening may be different from Western populations. We attempted to assess the importance of cholesterol screening in Japan.

DESIGN

A 13.2-year cohort study for cause-specific mortality.

SETTING

Three hundred randomly selected districts throughout Japan in which the National Survey on Circulatory Disorders 1980 was performed.

SUBJECTS

A total of 9216 community dwelling persons aged 30 years and over, with standardized serum cholesterol measurement and without a past history of cardiovascular disease.

RESULTS

There were 1206 deaths, which included 462 deaths due to cardiovascular disease with 79 coronary heart diseases. Hypercholesterolemia (>6.21 mmol L-1) showed a significant positive relation to coronary mortality (relative risk; 2.93, 95% confidence interval; 1.52-5.63) but not to stroke. Although hypocholesterolemia (<4.14 mmol L-1) was significantly associated with an increased risk of liver cancer, noncardiovascular, noncancer disease and all-cause mortality, these associations, except for liver cancer, disappeared after excluding deaths in the first 5 years of the follow-up. The multivariate adjusted attributable risk of hypercholesterolaemia for coronary disease was 0.98 per 1000 person-years, which was threefold higher than that of hypocholesterolemia for liver cancer: 0.32 per 1000 person-years. The attributable risk percentage of hypercholesterolaemia was 66% for coronary heart disease.

CONCLUSION

Similar to Western populations, it is recommended to provide screening for hypercholesterolaemia in Japan, especially for males, although its attributable risk for coronary disease might be small.

Expression of a constitutively active phosphatidylinositol 3-kinase induces process formation in rat PC12 cells. Use of Cre/loxP recombination system

It has been shown that inhibition of phosphatidylinositol (PI) 3-kinase blocks neurite outgrowth of PC12 cells stimulated with nerve growth factor. To further assess the role of PI 3-kinase, the active form of PI 3-kinase was expressed in PC12 cells by the adenovirus mediated introduction of a site-specific recombinase, Cre. After expression of the active PI 3-kinase, elevation of the levels of PI 3,4-diphosphate and PI 3,4,5-trisphosphate as well as formation of neurite-like processes was observed. The process formation was inhibited by wortmannin, a selective inhibitor of PI 3-kinase, which suggests that a high activity of PI 3-kinase was responsible for the formation of these processes. The processes lacked accumulation of F-actin and GAP43 at the growth cone, which suggests that the processes were incomplete compared with neurites. Instead, the bundling of microtubules was enhanced, which suggests that organization of the microtubules might be driving the process of elongation in the cells expressing the active PI 3-kinase. Induction of active PI 3-kinase resulted in activation of Jun N-terminal kinase but not of mitogen-activated protein kinase or protein kinase B/Rac protein kinase/Akt. These results suggest that PI 3-kinase is involved in neurite outgrowth in PC12 cells and that activation of Jun N-terminal kinase cascade may be involved in the cell response.

Enantioselective total synthesis of a potent antitumor antibiotic, fredericamycin A

The asymmetric total synthesis of both enantiomers of the potent antitumor antibiotic fredericamycin A (1) is detailed based on the protocol for the construction of its peri-hydroxy polyaromatic skeleton bearing the chirality at the spiro carbon via a strong base-induced cycloaddition of suitably substituted homophthalic anhydrides (AB-ring unit) with an optically active CDEF-ring unit. Particular attention has been given to the novel synthesis of the optically active spiro carbon center by a stereospecific rearrangement of optically active benzofuzed-trans-epoxy acylates leading to spirocyclopentane-1,1'-indane systems. This method is quite useful for the construction of an optically active spiro compound and was applied to the synthesis of the optically pure CDEF-ring unit of 1. Cycloaddition of the optically pure CDEF-ring unit to AB-ring units prepared via benzyne afforded two natural and unnatural-type hexacyclic compounds, which were converted to natural and unnatural enantiomers of synthetic 1, and the absolute configuration of natural 1 was determined as S.

Facile and efficient sulfenylation method using quinone mono-O,S-acetals under mild conditions

A novel sulfenylation method induced by aromatization of quinone mono-O,S-acetals is described. These sulfenylation reagents readily react with silyl enolethers or electron rich aromatic compounds to give sulfenylation products under mild conditions. In particular, O,S-acetal 2j, which possesses a pentafluorophenylthio function, is the most effective reagent from the standpoint of the adaptability for various substrates.

Microinjection of activated phosphatidylinositol-3 kinase induces process outgrowth in rat PC12 cells through the Rac-JNK signal transduction pathway

We have previously shown that sustained phosphatidylinositol (PI)-3 kinase activity is necessary for neurite outgrowth of PC12 cells induced by nerve growth factor (NGF). Microinjection of a constitutively active mutant of PI-3 kinase induced process formation suggesting that PI-3 kinase is indeed involved in the neurite outgrowth. However, the processes appeared to be incomplete neurites as they had very poor organization of F-actin and GAP43 antigen. The microtubule network was enhanced in the process-bearing cells and process formation was inhibited by colchicine suggesting that microtubules play an important role in process formation downstream of PI-3 kinase. These cell responses were inhibited by dominant-negative mutants of Rac and Sek1/SAPK but not by a dominant-negative mutant Ras and PD98059, a MAP kinase kinase (MEK) inhibitor, suggesting that not the Ras-MAP kinase pathway but the Rac-Jun N-terminal kinase (JNK) pathway is involved in process formation.

Spontaneous nitric oxide release accounts for the potent pharmacological actions of FK409

(+-)-(E)-Ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexeneamide (FK409), which was isolated from microbial products, has been reported to show a vasorelaxant effect through a mechanism similar to that of the organic nitrates such as isosorbide dinitrate. In solution at pH 7.4, FK409 decomposed and released nitric oxide (NO) spontaneously, while isosorbide dinitrate did not. In in vitro biological tests, FK409 inhibited norepinephrine-induced contraction in rat isolated aorta more potently than did isosorbide dinitrate (ED50 = 1.0 and 310 nM, respectively) and ADP-induced human platelet aggregation (IC50 = 0.75 and > 100 microM, respectively). Nitrite/nitrate was recovered in urine accumulated for 24 h after collection from rats given FK409 or isosorbide dinitrate (10 mg/kg p.o.). FK409 (10 mg/kg p.o.) increased the plasma cyclic GMP level and at the same time decreased the mean blood pressure in conscious rats, while isosorbide dinitrate (10 mg/kg p.o.) did not change these parameters significantly. These results suggest that FK409 produces these pharmacological actions via spontaneously released NO, unlike isosorbide dinitrate, and has a possibility of becoming a unique orally active drug for cardiovascular diseases as a new NO donor.

Changes in total serum cholesterol and other risk factors for cardiovascular disease in Japan 1980-1989

To monitor recent changes in Japan in diet and risk factors for cardiovascular disease (CVD), in the light of the decline on coronary heart disease, total serum cholesterol levels and other risk factors were compared between two nationwide health surveys in 1980 and 1989 conducted in the same population as the annual National Nutrition Surveys. Between 1980 and 1989, age-adjusted total serum cholesterol levels increased from 4.84 to 5.22 for men and from 4.91 to 5.24 mmol/l for women. Prevalence of age-adjusted hypercholesterolaemia of > or = 5.68 mmol/l (220 mg/dl) increased from 15.8% to 29.4% for men and from 18.4% to 30.6% for women. Decline in blood pressure was observed for both sexes. Prevalence of smoking decreased from 64.7% to 58.7% in men while prevalence in women remained low (from 10.1 to 9.9%). Considerable increases in total serum cholesterol levels do not offer an explanation of the recent decline in mortality from coronary heart disease in Japan. This may, in part, be related to a decline in blood pressure levels.

Adhesion of immature thymocytes to thymic stromal cells through fibronectin molecules and its significance for the induction of thymocyte differentiation

Only 10-15% of unseparated thymocytes adhered to culture plates precoated with fibronectin (FN), but 60-70% of the CD4-8- (double-negative) thymocyte population did. This population bound to FN but not to collagen, laminin, or vitronectin. Its binding to FN was inhibited by anti-FN antibody or a mixture of synthetic peptides corresponding to two different sites of FN, termed the V10 sequence and the RGDS (Arg-Gly-Asp-Ser) sequence, which interact, respectively, with the VLA-4 and VLA-5 FN receptors expressed on T-lineage cells. CD4-8- thymocytes also adhered to a monolayer of a thymic stromal cell clone, MRL104.8a, that induces growth-maintenance and differentiation of such thymocytes. The involvement of FN-FN receptor interaction in this adhesion was demonstrated by the following lines of evidence: (i) the MRL104.8a cells expressed FN molecules on their surface and (ii) the adhesion of CD4-8- thymocytes to MRL104.8a monolayers was almost completely inhibited by simultaneous addition of anti-FN antibody and a mixture of peptides (V10 plus RGDS) capable of binding to anti-FN receptors (VLA-4 and -5). Most important, blocking the adhesion of CD4-8- thymocytes to the thymic stromal cell monolayer resulted in potent inhibition of the differentiation of these thymocytes, which was otherwise induced toward the expression of CD4 and/or CD8 molecules. These results indicate that immature CD4-8- thymocytes adhere to thymic stromal cells preferentially through FN-FN receptor interaction and that such adhesion has a critical role in inducing and/or supporting the differentiation of these thymocytes.

Protection of bovine serum albumin from aggregation by Tween 80

In an attempt to explain the mechanism of protein stabilization conferred by detergents, we investigated the effect of Tween 80 on aggregation of bovine serum albumin (BSA) using circular dichroism (CD) and native gel electrophoresis. CD thermal scans showed that BSA denatures at about 54 degrees C in 20 mM Tris, pH 7.2, forming soluble aggregates. Because of this aggregation, thermal unfolding of BSA under these conditions was only partially reversible, as indicated by reduced signal changes in the second scan. On the basis of this observation, BSA was thermally stressed by incubating at 50, 60, or 70 degrees C for 15 min and then analyzed by native gel electrophoresis. There was no change at 50 degrees C before and after heating, whereas at 60 degrees C the intensity of the original monomer and dimer bands decreased and that of aggregate bands increased, with much greater changes at 70 degrees C. Addition of Tween 80 before heating reduced aggregation and increased the monomer content. These effects of Tween 80 were greater as its concentration was increased from 0.001 to 1%. There was no correlation between the protective effects and the critical micelle concentration (CMC) of Tween 80. Addition of Tween 80 after 15 min incubation at 70 degrees C, or after 70 degrees C heating followed by cooling to room temperature, had no effect, demonstrating that Tween 80 must be present during the 70 degrees C heating step to be protective. Native gel electrophoresis run at 60 degrees C showed multiple aggregate bands and new bands migrating around the dimer and monomer positions, which may correspond to precursors of aggregates. Tween 80 reduced formation of these new bands and aggregates, further demonstrating that it must be present during heating. Finally, CD thermal scans showed that 0.1% Tween 80 only slightly increased the apparent melting temperature. The observed stabilization of BSA against heat treatment is, therefore, due to Tween 80 altering aggregation behavior rather than inducing significant stabilization of the native state.

Autophagy supports generation of cells with high CD44 expression via modulation of oxidative stress and Parkin-mediated mitochondrial clearance

High CD44 expression is associated with enhanced malignant potential in esophageal squamous cell carcinoma (ESCC), amongst the deadliest of all human carcinomas. Although alterations in autophagy and CD44 expression are associated with poor patient outcomes in various cancer types, the relationship between autophagy and cells with high CD44 expression remains incompletely understood. In transformed esophageal keratinocytes, CD44^Low-CD24^High (CD44L) cells give rise to CD44^High-CD24^−/Low (CD44H) cells via epithelial-mesenchymal transition (EMT) in response to transforming growth factor (TGF)-β. We couple patient samples and xenotransplantation studies with this tractable in vitro system of CD44L to CD44H cell conversion to investigate the functional role of autophagy in generation of cells with high CD44 expression. We report that high expression of the autophagy marker cleaved LC3 expression correlates with poor clinical outcome in ESCC. In ESCC xenograft tumors, pharmacological autophagy inhibition with chloroquine derivatives depletes cells with high CD44 expression while promoting oxidative stress. Autophagic flux impairment during EMT-mediated CD44L to CD44H cell conversion in vitro induces mitochondrial dysfunction, oxidative stress and cell death. During CD44H cell generation, transformed keratinocytes display evidence of mitophagy, including mitochondrial fragmentation, decreased mitochondrial content and mitochondrial translocation of Parkin, essential in mitophagy. RNA interference-mediated Parkin depletion attenuates CD44H cell generation. These data suggest that autophagy facilitates EMT-mediated CD44H generation via modulation of redox homeostasis and Parkin-dependent mitochondrial clearance. This is the first report to implicate mitophagy in regulation of tumor cells with high CD44 expression, representing a potential novel therapeutic avenue in cancers where EMT and CD44H cells have been implicated, including ESCC.

Hypervalent iodine(III)-induced intramolecular cyclization of alpha-(aryl)alkyl-beta-dicarbonyl compounds: a convenient synthesis of benzannulated and spirobenzannulated compounds

A novel hypervalent iodine(III)-induced direct intramolecular cyclization of alpha-(aryl)alkyl-beta-dicarbonyl compounds has been described. Both meta- and para-substituted phenol ether derivatives containing acyclic or cyclic 1,3-dicarbonyl moieties at the side chain undergo this reaction in a facile manner. The reactions afford benzannulated and spirobenzannulated compounds that are of biological importance. The reaction is found to be general, mild, and high yielding. The mechanism of the reaction has been shown to involve a cation radical intermediate.

Stroke incidence and case fatality in Shiga, Japan 1989-1993

BACKGROUND

This paper describes incidence rates and case-fatality for sub-types of stroke using data collected in Takashima, Shiga, Japan, from 1989 to 1993 and compares these with similar registers in other parts of Japan.

METHODS

Registered patients included all residents of the county who experienced a first-ever stroke. Stroke was defined as sudden onset of neurological symptoms which continued for a minimum of 24 hours or led to death. Almost all such patients are hospitalized in this country. Early case fatality was defined as patients who died within 28 days of stroke onset. Diagnosis of stroke type was based on clinical symptoms as well as computed tomography (CT) scans.

RESULTS

Age-adjusted incidence rates for stroke per 100,000 population aged 35 years and older were 268.7 for men and 167.5 for women. The age-specific incidence rate of both cerebral infarction and cerebral haemorrhage increased with advancing age. The occurrence of cerebral infarction in men was twice as high as in women. The 28-day case fatality for all sub-types of stroke was 16.1% in men and 15.8% in women. Case fatality for cerebral infarction, cerebral haemorrhage, and subarachnoid haemorrhage was 10.7%, 22.4% and 28.6% respectively.

CONCLUSIONS

Takashima County has a moderately high stroke incidence rate and case fatality compared with other similar studies in Japan. The incidence rate of cerebral infarction in men is twice that in women, while other sub-types of stroke showed smaller differences. In order to decrease the incidence of stroke in Japan, greater efforts at primary prevention will be necessary, in particular, it is important to prevent cerebral infarction in men.

Common T cell receptor clonotype in lacrimal glands and labial salivary glands from patients with Sjögren's syndrome

Sjogren's syndrome (SS) is an autoimmune disease characterized by lymphocytic infiltration into lacrimal and salivary glands leading to symptomatic dry eyes and mouth. Immunohistological studies have clarified that the majority of infiltrating lymphocytes around the lacrimal glands and labial salivary glands are CD4 positive alphabeta T cells. To analyze the pathogenesis of T cells infiltrating into lacrimal and labial salivary glands, we examined T cell clonotype of these cells in both glands from four SS patients using PCR-single-strand conformation polymorphism (SSCP) and a sequencing method. SSCP analysis showed that some infiltrating T cells in both glands expand clonally, suggesting that the cells proliferate by antigen-driven stimulation. Intriguingly, six to sixteen identical T cell receptor (TCR) Vbeta genes were commonly found in lacrimal glands and labial salivary glands from individual patients. This indicates that some T cells infiltrating into both glands recognize the shared epitopes on autoantigens. Moreover, highly conserved amino acid sequence motifs were found in the TCR CDR3 region bearing the same TCR Vbeta family gene from four SS patients, supporting the notion that the shared epitopes on antigens are limited. In conclusion, these findings suggest that some autoreactive T cells infiltrating into the lips and eyes recognized restricted epitopes of a common autoantigen in patients with SS.

Natural history and left ventricular response in chronic aortic regurgitation

This study was aimed at clarifying the natural history and left ventricular response in aortic regurgitation using M-mode echocardiography. We analyzed the history and echocardiographic data on 94 patients, who were divided into 4 stages according to symptoms. The duration of the asymptomatic period, which represents pure volume overload, is long, and the period of minimal symptoms, combined volume and pressure overload, is relatively short. Patients with overt heart failure due to impaired contractility can survive longer than is usually believed, and the factor that predicted the onset of heart failure was a decrease in fractional shortening > 3.8 percentage points.

Sequence and expression of rat ICAM-1

We have isolated cDNA clones-coding for rat intercellular adhesion molecule-1 (RICAM-1) from a cDNA library constructed from rat Ax cells stimulated with IL-1 beta using the mouse ICAM-1 cDNA as a hybridization probe. The RICAM-1 sequence shows 79.1% homology with mouse ICAM-1 and 55.6% homology with human ICAM-1 at the nucleic acid level. In order to examine the expression of RICAM-1 on Chinese hamster ovary (CHO) cells, we constructed the vector, pSV-RICAM1-neo, containing the SV40 promoter. Flowcytometric analysis showed that CHO-K1 cells transfected with pSV-RICAM1-neo expressed high amounts of RICAM-1 on their surfaces.