Prevalence of enteric bacteria that inhibit growth of enterohaemorrhagic Escherichia coli O157 in humans.

Enterohaemorrhagic Escherichia coli O157 (O157) is infectious to humans, particularly children, at very low doses and causes not only haemorrhagic colitis but also other serious symptoms. To investigate an association between intestinal bacterial flora and resistance to such infections, we screened faecal samples for the presence of enteric bacteria that are able to suppress the growth of O157. Samples from 303 individuals, 35 children (aged < or =6 years) and 268 adults (aged 20-59 years), were examined. Colonies with different appearances on sorbitol MacConkey agar medium were screened for the production of bacteriocins inhibitory for O157 in an overlay agar plate assay. O157-inhibiting strains were isolated from 52 individuals. The prevalence of these bacteria tended to rise with age, and was significantly higher among 40- to 59-year-old adults (23/101, 22.8%) than among children (3/35, 8.6%; P<0.05). To test the hypothesis that these bacteriocin-producing strains contribute to resistance against O157 in human adults, we examined faecal samples of 25 healthy O157 carriers. Inhibitory bacteria were more prevalent among the latter (9/25, 36.0%) than among age-matched subjects who did not carry O157 (49/268, 18.3%). It appears, therefore, that inhibitory bacteria in the human gut may play a role in inhibiting propagation of O157 and/or suppressing expression of virulence factors by this pathogen.

Structure and expression of 12-oxophytodienoate reductase (subgroup I) genes in pea, and characterization of the oxidoreductase activities of their recombinant products.

Recently, we observed that expression of a pea gene (S64) encoding an oxophytodienoic acid reductase (OPR) was induced by a suppressor of pea defense responses, secreted by the pea pathogen Mycosphaerella pinodes. Because it is known that OPRs are usually encoded by families of homologous genes, we screened for genomic and cDNA clones encoding members of this putative OPR family in pea. We isolated five members of the OPR gene family from a pea genomic DNA library, and amplified six cDNA clones, including S64, by RT-PCR (reverse transcriptase-PCR). Sequencing analysis revealed that S64 corresponds to PsOPR2, and the amino acid sequences of the predicted products of the six OPR-like genes shared more than 80% identity with each other. Based on their sequence similarity, all these OPR-like genes code for OPRs of subgroup I, i.e., enzymes which are not required for jasmonic acid biosynthesis. However, the genes varied in their exon/intron organization and in their promoter sequences. To investigate the expression of each individual OPR-like gene, RT-PCR was performed using gene-specific primers. The results indicated that the OPR-like gene most strongly induced by the inoculation of pea plants with a compatible pathogen and by treatment with the suppressor from M. pinodes was PsOPR2. Furthermore, the ability of the six recombinant OPR-like proteins to reduce a model substrate, 2-cyclohexen-1-one (2-CyHE), was investigated. The results indicated that PsOPR1, 4 and 6 display robust activity, and PsOPR2 has a most remarkable ability to reduce 2-CyHE, whereas PsOPR3 has little and PsOPR5 does not reduce this compound. Thus, the six OPR-like proteins can be classified into four types. Interestingly, the gene structures, expression profiles, and enzymatic activities used to classify each member of the pea OPR-like gene family are clearly correlated, indicating that each member of this OPR-like family has a distinct function.

[Field epidemiological investigation on an outbreak of Chlamydia pneumoniae infection--first recognized incidence in a nursing home for elderly in Japan].

Chlamydia pneumoniae (C. pneumoniae) is an emerging pathogen recognized in 1989. Although C. pneumoniae infection is known to give a great impact on public health in western countries, many aspects remain unclarified in Japan. During December 1999 and March 2000, respiratory symptoms among residents and employees in a nursing home for elderly implicated an outbreak of C. pneumoniae infection. Field epidemiological investigation confirmed that this is the first outbreak recognized in a nursing home setting in Japan, involving 31/59 (15 confirmed) residents and 9/41 (2 confirmed) employees. Fifteen residents developed severe C. pneumoniae infections including one fatal outcome with pneumonia. Epidemiological analysis did not identify risk factors which induce infection or severe illness by C. pneumoniae for the residents. However, for the employees, frequent contact with the residents was demonstrated as a significant risk factor for the infection. None of 13 employees who had no contact with the residents presented C. pneumoniae infection, while nine out of 28 employees who had frequent contact developed C. pneumoniae infections (RR infinite, P = 0.04). These results indicated that C. pneumoniae infection spread gradually by human-to-human droplet transmission without specific risk factors. This study raised current problems in diagnosing and treating the C. pneumoniae infection and the need to enhance the awareness of this disease.

Structural confirmation of 15-norlubiminol and 15-norepilubiminol, isolated from Solanum aethiopicum, by chemical conversion from lubimin and epilubimin, and their antifungal activity.

15-Norlubiminol and 15-norepilubiminol were obtained from Solanum aethiopicum as an inseparable 1:1 mixture in a relatively poor yield to that of the major phytoalexins, lubimin and epilubimin. Their structures were confirmed by chemical conversion starting from lubimin and epilubimin. Baeyer-Villiger oxidation of the protected lubimins with m-chloroperoxybenzoic acid provided the desired formates. Deoxygenation with triphenylphosphine selenide and subsequent methanolysis provided 15-norlubiminols, whose 1H-NMR spectra were respectively identical with that of the corresponding isomer in the natural 15-norlubiminol mixture. The antifungal activity of 15-norlubiminols would be weaker than that of lubimins.

Total synthesis of (+)-albicanol and (+)-albicanyl acetate.

The drimane sesquiterpenes, (+)-albicanol (2) and (+)-albicanyl acetate (3), were synthesized from an optically active bicyclic diol [(+)-1] that had been obtained via the recently developed optical resolution of a general synthetic intermediate for drimane sesquiterpenes. The crucial step in the previous syntheses was markedly improved by the modified Wittig methylenation of a silyloxy ketone (7). The high overall yield (77% in 4 or 5 steps from (+)-1) by this total synthesis makes it possible to synthesize the other biologically active drimane sesquiterpenes.

Natural history of hypertrophic cardiomyopathy: Japanese experience.

BACKGROUND AND OBJECTIVES: Most patients with hypertrophic cardiomyopathy (HCM) remain clinically stable for long periods of time, whereas some patients progress to severe systolic dysfunction. Therefore, the natural history of HCM is largely unknown. METHODS: The present study followed up 59 patients with HCM (32 males, 27 females, mean age 38.6 +/- 13.6 years) for 10 years or more (mean 16.0 +/- 4.7 years) after the initial diagnosis. RESULTS: Eight of 17 patients who showed abnormal Q-waves at the initial examination had lost Q-waves, suggesting remodeling from asymmetric to generalized hypertrophy. The thickness of the interventricular septum showed remarkable changes, increasing by > or = 5 mm in 7 patients and decreasing by > or = 5 mm in 21. These observations indicate that ventricular remodeling occurs in patients with HCM. Follow-up electrocardiography demonstrated new Q-waves in 10 patients and bundle branch blocks or intraventricular conduction disturbances in 13. Left ventricular end-diastolic diameter increased from 41.6 to 48.1 mm, associated with a decrease in fractional shortening from 40.6% to 34.0%. Left ventricular systolic dysfunction, defined as left ventricular end-diastolic diameter > 55 mm or fractional shortening < 25%, developed in 13 patients. These observations indicate that myocardial disease including the conduction system is progressive in patients with HCM and finally deteriorates to systolic dysfunction. Left ventricular outflow obstruction also presented evolutional changes. At the initial study, 23 patients showed systolic anterior motion of the mitral valves. Systolic anterior motion disappeared in 13 patients, reduced in 2, increased in 2, and remained stable in only 6. One patient without systolic anterior motion at the initial study developed new systolic anterior motion. Impaired left ventricular filling increased left atrial diameter from 35.5 to 46.9 mm and atrial fibrillation frequently developed (24 patients). CONCLUSIONS: These findings suggest that HCM is a slowly progressive disease which develops evolutional remodeling of left ventricular hypertrophy and outflow obstruction, eventually progressing to systolic dysfunction with cavity dilation and wall thinning.

(-)-Semivioxanthin, a new abscisic active compound against Hinoki cypress leaves isolated from Cryptosporiopsis abietina.

The new naphthopyrone, (-)-semivioxanthin (1) was isolated from Cryptosporiopsis abietina. The structure of 1 was determined as the reversed optical isomer of semivioxanthin by comparing its spectroscopic data with those of semivioxanthin. Compound 1 exhibited abscisic activity against Hinoki cypress leaves and antifungal activity against Cladosporium herbarum.

Syntheses of stereochemically restricted lactone-type analogues of jasmonic acids.

5-Oxa-7-epi-jasmonic acid and 5-oxa-jasmonic acid, which are stereochemically restricted lactone-type analogues of jasmonic acids, were synthesized via three-component coupling of 2(5H)-furanone, tert-butyl acetate and 1-bromo-2-pentyne. After acidic deprotection of the tert-butyl esters, the (Z)-olefin was introduced by catalytic partial reduction with the Lindlar catalyst to give the desired analogues.

Wound-induced expression of a tobacco peroxidase is not enhanced by ethephon and suppressed by methyl jasmonate and coronatine.

In tobacco plants, wounding induces production of a set of defense-related proteins such as basic pathogenesis-related (PR) proteins and proteinase inhibitors (PIs) via the jasmonate/ethylene pathway. Although class III plant peroxidase (POX) is also wound-inducible, the regulatory mechanism for its wound-induced expression is not fully understood. Here, we describe that a tobacco POX gene (tpoxN1), which is constitutively expressed in roots, is induced locally 30 min after wounding and then systemically in tobacco plants. Infection of necrotizing virus also induced tpoxN1 gene. The wound-induced expression was not enhanced by known wound-signal compounds such as methyl jasmonate (MeJA) and ethephon in contrast to other wound-inducible genes such as basic PR-1 and PI-II genes. And treatment with MeJA and coronatine, biological analogs of jasmonate, rather suppressed the tpoxN1 expression. Salicylic acid, an antagonist of jasmonate-based wound signaling, did not suppress the wound-induced expression of tpoxN1. Only spermine, which is reported as an endogenous inducer for acidic PR genes in tobacco mosaic virus-infected tobacco leaves, could induce tpoxN1 gene expression. These results suggest that wound-induced expression of the tpoxN1 gene is regulated differently from that of the basic PR and PI-II genes.

Synthesis and potato cell expansion-inducing activity of the stereochemically restricted bicyclic analogue of 7-epi-jasmonic acid.

The stereochemically restricted bicyclic analogue of 7-epi-jasmonic acid was synthesized from a known bicyclo[3.3.0]octane derivative. The enol triflate derived from the bicyclic compound was subjected to palladium-catalyzed coupling with allyltributyltin to give the desired carbon skeleton. Selective catalytic hydrogenation and subsequent acidic hydrolysis gave a new bicyclic analogue of 7-epi-jasmonic acid. The ACC conjugate of the bicyclic analogue was also synthesized. This ACC conjugate exhibited only slightly weaker potato cell expansion-inducing activity than that of the JA standard.

Life-style related factors and idiopathic dilated cardiomyopathy--a case-control study using pooled controls.

A case-control study was conducted to investigate how basic habits of life including dietary habit, physical activity, cigarette smoking, and drinking, are involved in the development of idiopathic dilated cardiomyopathy (DCM). Collection of cases was entrusted to the clinical research group of DCM, and national pooled controls established by sex and age category by the epidemiological research group of intractable diseases were used to ensure representativeness of the controls. Fifty-eight cases of DCM which developed in and after January 1991 were collected, and 5,912 controls matched with the cases by residential area, sex, and age were selected. Analysis of the results of the study showed that items in the questionnaire suggestive of viral infection, such as "susceptibility to common cold" and "susceptibility to diarrhea", items concerning dietary habit, including "taking no breakfast", "ingestion of salty food", and "ingestion of fatty food", and such items as "cigarette smoking" and "lack of sleep" tended to be observed in the case group at significantly higher frequencies. Since viral infection has been suspected as a causative factor of DCM, further research of this area is thought to be of particular importance for determining the etiology of DCM.

Total Synthesis of (+)-(2S,3R)-Piscidic Acid via Catalytic Asymmetric Dihydroxylation of a Trisubstituted Olefin.

(+)-(2S,3R)-Piscidic acid was efficiently synthesized with high optical purity (90% e.e.) via Sharpless catalytic asymmetric dihydroxylation of a trisubstituted olefin in only 6 steps from commercially available 4-hydroxyphenylpyruvic acid as the starting material. The reaction proceeded with high optical purity by using the chiral ligands, dihydroquinidine 2,5-diphenyl-4,6-pyrimidinediyl diether or dihydroquinidine 1,4-anthraquinonediyl diether.

Syntheses and Potato Tuber-inducing Activities of Unnatural Long-chain OPC-9:0 and OPC-10:0.

The unnatural long-chain OPCs, OPC-9:0 and OPC-10:0, were respectively synthesized from the ethyl esters of OPC-7:0 and OPC-8:0. C2-carbon elongation was achieved via alkylation of the enolate of tert-butyl acetate. The potato tuber-inducing activity of OPC-10:0, as well as OPC-8:0, -6:0 and -4:0, was similar to that of jasmonic acid. OPC-9:0 also exhibited weak tuber-inducing activity.

Altered calcium handling in compensated hypertrophied rat cardiomyocytes induced by pressure overload.

To investigate Ca2+ handling in compensated hypertrophied cardiomyocytes, we measured Ca2+ transients and contraction of hypertrophied rat left ventricular myocytes induced by aortic constriction (AC). The fluorescence ratio (I405/I480) after indo-1/AM loading and circumferential length were simultaneously measured in isolated myocytes. The amplitude of Ca2+ transients (Ca-Amp) was higher in rats with AC than in sham-operated rats (Sham) (0.25 +/- 0.08 vs 0.17 +/- 0.05). There was a positive correlation between Ca-Amp and fractional shortening (FS) in both AC and Sham rats, whereas the ratio of FS/Ca-Amp was smaller in AC rats. These observations suggest that compensated hypertrophied cardiomyocytes exhibit an adaptive increase in Ca-Amp, associated with reduced myofilament responsiveness to an increase in Ca2+. Isoproterenol and forskolin increased Ca-Amp and FS, and decreased time to 50% decline of Ca2+ transients. Although myocytes from AC rats exhibited reduced responsiveness to isoproterenol, responses to forskolin did not differ between the 2 groups. The reduced beta-adrenergic response in Ca2+ handling was probably due to altered beta-adrenoceptor numbers, G-protein function and/or their coupling process.

Improved Synthesis of the C8-C23 Segment of Aplysiatoxins via Asymmetric Dihydroxylation of the Chiral Homoallylic Alcohol.

Important intermediate 2 of the segment (3) possessing four sequential asymmetric centers (C9-C12) of aplysiatoxins was synthesized via dihydroxylation of 5 in only 7 steps from methyl (S)-3-hydroxy-2-methylpropionate. Another promising compound (10a) was also synthesized in only 6 steps via asymmetric dihydroxylation of chiral homoallylic alcohol 4 as the key step.

Syntheses and Potato Tuber-inducing Activity of Coronafacic Acid Analogues.

Coronafacic acid (1) is an acid component of coronatine, and has been isolated from several pathovars of Pseudomonas syringae. Syntheses of C6-non- and C6-alkyl-substituted analogues of 1 were accomplished via intramolecular 1,6-conjugate addition as the key step. Among them, 1 and four C6-alkyl-substituted analogues exhibited potato tuber-inducing activity, but the C6-non-substituted analogue did not. It was revealed that a certain length of the C6-alkyl group was necessary to exhibit activity.

Syntheses of 3-Oxa-OPC and 2-Fluoro-OPC Homologues.

SYNOPSIS: 3-Oxa-OPC and 2-fluoro-OPC homologues which do not undergo ß-oxidation were synthesized from esters of odd-numbered OPC homologues by a short-step procedure. The 3-oxa-OPC homologues were synthesized via etherification of an alcohol with tert-butyl bromoacetate under phase-transfer conditions. The 2-fluoro-OPC homologues were synthesized via the addition of the trichloromethyl anion to an aldehyde and subsequent fluorination.

Mutations in the cardiac troponin I gene associated with hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM), the most common cause of sudden death in the young, is an autosomal dominant disease characterized by ventricular hypertrophy accompanied by myofibrillar disarrays. Linkage studies and candidate-gene approaches have demonstrated that about half of the patients have mutations in one of six disease genes: cardiac beta-myosin heavy chain (c beta MHC), cardiac troponin T (cTnT), alpha-tropomyosin (alpha TM), cardiac myosin binding protein C (cMBPC), ventricular myosin essential light chain (vMLC1) and ventricular myosin regulatory light chain (vMLC2) genes. Other disease genes remain unknown. Because all the known disease genes encode major contractile elements in cardiac muscle, we have systematically characterized the cardiac sarcomere genes, including cardiac troponin I (cTnI), cardiac actin (cACT) and cardiac troponin C (cTnC) in 184 unrelated patients with HCM and found mutations in the cTnI gene in several patients. Family studies showed that an Arg145Gly mutation was linked to HCM and a Lys206Gln mutation had occurred de novo, thus strongly suggesting that cTnI is the seventh HCM gene.

Changes in population cholesterol levels and coronary heart disease deaths in seven countries.

BACKGROUND: Are trends in coronary heart disease deaths based on risk factor changes? OBJECTIVE: To study the relationship between trends in coronary deaths and changes in blood cholesterol in the Seven Countries Study. MATERIAL AND METHODS: Sixteen cohorts of men aged 40-59 years from seven countries (U.S.A., Finland, the Netherlands, Italy, Croatia (former Yugoslavia), Serbia (former Yugoslavia), Greece, Japan) were units for the analyses of serum cholesterol measured at entry and after 5 and 10 years, and for mortality over 25 years. RESULTS: In the populations, the ecological relationship of mean serum cholesterol at entry to late coronary heart disease death rates during the 10- to 25-year follow-up was weak, with an R-square of 0.31. Cholesterol measurements made at year 10, and an indicator of cholesterol change during the first 10 years, increased the association (R-square, 0.49). A negative and significant interaction was shown between baseline population cholesterol levels and their 10-year change. As an indicator of acceleration in mortality, cholesterol change over 10 years was also positively correlated (partial R-square 0.44) with the ratio of 25-year to 5-year deaths. CONCLUSIONS: In the Seven Countries Study, late coronary heart disease death rates are largely "explained' by changes in blood cholesterol levels during the early phases of the study, mainly due to increases in lower cholesterol levels among some cohorts.