Genetic diversity of Lactobacillus delbrueckii isolated from raw milk in Hokkaido, Japan.

Lactic acid bacteria (LAB) play important roles in acid production and flavor formation in fermented dairy products. Lactic acid bacteria strains with distinct characteristics confer unique features to products. Diverse LAB have been identified in raw milk and traditional fermented milk prepared from raw milk. However, little is known about LAB in raw milk in Japan. To preserve diverse LAB as potential starters or probiotics for future use, we have isolated and identified various kinds of LAB from raw milk produced in Japan. In this study, we focused on Lactobacillus delbrueckii, one of the most important species in the dairy industry. We identified L. delbrueckii subspecies isolated from raw milk in Hokkaido, Japan, by analyzing intraspecific diversity using 4 distinct methods, hsp60 cluster analysis, multilocus sequence analysis, core-genome analysis, and whole-genome analysis based on average nucleotide identity. The subspecies distribution and a new dominant subset of L. delbrueckii from raw milk in Japan were revealed. The discovery of new strains with different genotypes is important for understanding the geographic distribution and characteristics of the bacteria and further their use as a microbial resource with the potential to express unconventional flavors and functionalities. The strains identified in this study may have practical applications in the development of fermented dairy products.

Coping strategies and risk of cardiovascular disease incidence and mortality: the Japan Public Health Center-based prospective Study.

AIMS: Coping strategies may be significantly associated with health outcomes. This is the first study to investigate the association between baseline coping strategies and cardiovascular disease (CVD) incidence and mortality in a general population cohort. METHODS AND RESULTS: The Japan Public Health Center-based prospective Study asked questions on coping in its third follow-up survey (2000-04). Analyses on CVD incidence and mortality included 57 017 subjects aged 50-79 without a history of CVD and who provided complete answers on approach- and avoidance-oriented coping behaviours and strategies. Cox regression models, adjusted for confounders, were used to determine hazard ratios (HRs) according to coping style. Mean follow-up time was 7.9 years for incidence and 8.0 years for mortality.The premorbid use of an approach-oriented coping strategy was inversely associated with incidence of stroke (HR = 0.85; 95% CI, 0.73-1.00) and CVD mortality (HR = 0.74; 95% CI, 0.55-0.99). Stroke subtype analyses revealed an inverse association between the approach-oriented coping strategy and incidence of ischaemic stroke (HR = 0.79; 95% CI, 0.64-0.98) and a positive association between the combined coping strategy and incidence of intra-parenchymal haemorrhage (HR = 2.03; 95% CI, 1.01-4.10). Utilizing an avoidance coping strategy was associated with increased mortality from ischaemic heart disease (IHD) only in hypertensive individuals (HR = 3.46; 95% CI, 1.07-11.18). The coping behaviours fantasizing and positive reappraisal were associated with increased risk of CVD incidence (HR = 1.24; 95% CI, 1.03-1.50) and reduced risk of IHD mortality (HR = 0.63; 95% CI, 0.40-0.99), respectively. CONCLUSION: An approach-oriented coping strategy, i.e. proactively dealing with sources of stress, may be associated with significantly reduced stroke incidence and CVD mortality in a Japanese population-based cohort.

Detection of methicillin-resistant Staphylococcus pseudintermedius ST169 and novel ST354 SCCmec II-III isolates related to the worldwide ST71 clone.

The recent appearance of methicillin-resistant Staphylococcus pseudintermedius (MRSP) is a concern for both veterinary and human healthcare. MRSP clonal lineages with sequence type (ST) 71-spa t02-staphylococcal cassette chromosome mec (SCCmec) II-III and ST68-spa t06-SCCmec V have spread throughout Europe and North America, respectively. The current study compared the molecular characteristics of 43 MRSP isolates from dogs in Japan with those of MRSP from previous reports using multilocus sequence typing based on seven housekeeping genes, SCCmec typing, and detection of antimicrobial resistance genes. Three related clonal lineages, ST71, ST169, and the newly registered ST354, were observed in SCCmec II-III isolates from Japan, despite MRSP SCCmec II-III isolates being thought to belong to a single clonal lineage. The majority of SCCmec II-III isolates belonging to ST169 (9/11) and ST354 (3/3), but not ST71 (0/11), harboured tetM. Four STs were observed for the SCCmec V isolates; however, neither ST68 nor related STs were found in the Japanese MRSP isolates. In conclusion, MRSP SCCmec II-III isolates from Japan belonged to ST71 and related STs (ST169 and ST354). A variety of MRSP SCCmec V clones, including some novel clones, were identified.

Primary systemic carnitine deficiency is caused by mutations in a gene encoding sodium ion-dependent carnitine transporter.

Primary systemic carnitine deficiency (SCD; OMIM 212140) is an autosomal recessive disorder characterized by progressive cardiomyopathy, skeletal myopathy, hypoglycaemia and hyperammonaemia. SCD has also been linked to sudden infant death syndrome. Membrane-physiological studies have suggested a defect of the carnitine transport system in the plasma membrane in SCD patients and in the mouse model, juvenile visceral steatosis. Although the responsible loci have been mapped in both human and mouse, the underlying gene has not yet been identified. Recently, we cloned and analysed the function of a novel transporter protein termed OCTN2. Our observation that OCTN2 has the ability to transport carnitine in a sodium-dependent manner prompted us to search for mutations in the gene encoding OCTN2, SLC22A5. Initially, we analysed the mouse gene and found a missense mutation in Slc22a5 in jvs mice. Biochemical analysis revealed that this mutation abrogates carnitine transport. Subsequent analysis of the human gene identified four mutations in three SCD pedigrees. Affected individuals in one family were homozygous for the deletion of a 113-bp region containing the start codon. In the second pedigree, the affected individual was shown to be a compound heterozygote for two mutations that cause a frameshift and a premature stop codon, respectively. In an affected individual belonging to a third family, we found a homozygous splice-site mutation also resulting in a premature stop codon. These mutations provide the first evidence that loss of OCTN2 function causes SCD.

Cognitive and affective impairments of a novel SCA/MND crossroad mutation Asidan.

BACKGROUND: A variety of hereditary spinocerebellar ataxia (SCA) develops a broad spectrum of both ataxia and non-ataxia symptoms. Cognitive and affective changes are one such non-ataxia symptoms, but have been described only in hereditary SCAs with exonic CAG gene expansion. METHODS: We newly found intronic hexanucleotide GGCCTG gene expansion in NOP56 gene as the causative mutation (=SCA36) in nine unrelated Japanese familial SCA originating from Asida river area in the western part of Japan, thus nicknamed Asidan for this mutation. These patients show unique clinical balance of cerebellar ataxia and motor neuron disease (MND), locating on the crossroad of these two diseases. In the nine families, 14 patients were clinically examined and genetically confirmed to Asidan. In the present study, we examined cognitive and affective analyses on 12 patients (seven men and five women) who agreed to join the examination with average age at onset of 53.1 ± 3.2 years, average duration of 12.1 ± 5.2 years, and current average age at 65.1 ± 6.2 years. RESULTS: The 12 Asidan patients demonstrated a significant decrease in their frontal executive functions measured by frontal assessment battery (FAB) and Montreal cognitive assessment (MoCA) compared with age- and gender-matched controls, whilst mini-mental state examination (MMSE) and Hasegawa dementia score-revised (HDS-R) were within normal range. The decline of frontal executive function was related to their disease duration and scale for the assessment and rating of ataxias (SARA). They also demonstrated mild depression and apathy. Single-photon emission tomography (SPECT) analysis showed that these Asidan patients showed decline of regional cerebral blood flow (rCBF) in a particular areas of cerebral cortices such as Brodmann areas 24 and 44-46. CONCLUSION: These data suggest that the patients with Asidan mutation show unique cognitive and affective characteristics different from other hereditary SCAs with exonal CAG expansion or MND.

f Electron contribution to the change of electronic structure in CeRu2Si2 with temperature: a Compton scattering study.

High resolution Compton profiles have been measured in the single crystal of CeRu(2)Si(2) above and below the Kondo temperature to elucidate the change of the Ce-4f electron from localized to itinerant states. Two-dimensional electron occupation number densities projected on the first Brillouin zone, which are obtained after a series of analyses, clearly specify the difference between itinerant and localized states. The contribution of Ce-4f electrons to the electronic structure is discussed by contrast with a band calculation.

Mapping of murine diabetogenic gene mody on chromosome 7 at D7Mit258 and its involvement in pancreatic islet and beta cell development during the perinatal period.

Mutation of the murine maturity-onset diabetes mellitus of the young (Mody) locus induces diabetes, but the effects of its homozygosity on the pancreas remain unknown. F2 mice were obtained by F1 (diabetic C57BL6 x normal Mus musculus castaneus) crosses. About 20% of the F2 progeny developed diabetes by 2 wk of age, 50% of the progeny were normal at 2 wk and developed diabetes between 5 and 8 wk of age, and the remaining 30% did not develop diabetes. Quantitative trait locus analysis using blood glucose levels of 118 F2 mice at 2 wk of age and 5-8 wk of age located Mody within 3 cM of D7Mit258. Histopathological investigation revealed hypoplastic islets (approximately 33% of that of wild-type mice) and a lower density of beta cells (approximately 20% of wild-type) with a reciprocal dominance of alpha cells (four times that of wild-type) in Mody homozygotes. Electron microscopic observations revealed a specific decrease in the number of insulin secretory granules and a lower density of beta cells. Ratios of insulin to glucagon contents confirmed specific decreases in insulin content: 0.01 for homozygotes, 0.54 for heterozygotes, and 1.11 for wild-type mice on day 14. These results suggest that Mody is involved in both islet growth and beta cell function.

A mutation in the insulin 2 gene induces diabetes with severe pancreatic beta-cell dysfunction in the Mody mouse.

The mouse autosomal dominant mutation Mody develops hyperglycemia with notable pancreatic beta-cell dysfunction. This study demonstrates that one of the alleles of the gene for insulin 2 in Mody mice encodes a protein product that substitutes tyrosine for cysteine at the seventh amino acid of the A chain in its mature form. This mutation disrupts a disulfide bond between the A and B chains and can induce a drastic conformational change of this molecule. Although there was no gross defect in the transcription from the wild-type insulin 2 allele or two alleles of insulin 1, levels of proinsulin and insulin were profoundly diminished in the beta cells of Mody mice, suggesting that the number of wild-type (pro)insulin molecules was also decreased. Electron microscopy revealed a dramatic reduction of secretory granules and a remarkably enlarged lumen of the endoplasmic reticulum. Little proinsulin was processed to insulin, but high molecular weight forms of proinsulin existed with concomitant overexpression of BiP, a molecular chaperone in the endoplasmic reticulum. Furthermore, mutant proinsulin expressed in Chinese hamster ovary cells was inefficiently secreted, and its intracellular fraction formed complexes with BiP and was eventually degraded. These findings indicate that mutant proinsulin was trapped and accumulated in the endoplasmic reticulum, which could induce beta-cell dysfunction and account for the dominant phenotype of this mutation.

Inheritance pattern of familial moyamoya disease: autosomal dominant mode and genomic imprinting.

BACKGROUND: Although the aetiology of moyamoya disease (MMD) has not been fully clarified, genetic analysis of familial MMD (F-MMD) has considerable potential to disclose it. OBJECTIVE: To determine the inheritance pattern and clinical characteristics of F-MMD to enable precise genetic analyses of the disease. METHODS: 15 highly aggregated Japanese families (52 patients; 38 women and 14 men) with three or more affected members were examined. The difference in categories of age at onset (child onset, adult onset and asymptomatic) between paternal and maternal transmission was compared by chi2 statistics. RESULTS: In all families there had been three or more generations without consanguinity, and all types of transmission, including father-to-son, were observed. Among a total of 135 offspring of affected people, 59 (43.7%) were patients with MMD or obligatory carriers. Affected mothers were more likely to produce late-onset (adult-onset or asymptomatic) female offspring (p = 0.007). CONCLUSIONS: The mode of inheritance of F-MMD is autosomal dominant with incomplete penetrance. Thus, in future genetic studies on F-MMD, parametric linkage analyses using large families with an autosomal dominant mode of inheritance are recommended. Genomic imprinting may be associated with the disease.

Proliferative kinetics and chromosome damage in trisomy 21 lymphocyte cultures exposed to gamma-rays and bleomycin.

Lymphocytes from patients with Down's syndrome (trisomy 21) have been investigated for cell cycle kinetics, cell proliferation delays, and chromosomal aberrations after exposure to gamma-rays or bleomycin. Analysis by sister chromatid differential staining revealed that trisomy 21 lymphocytes started cell cycling about 5 hr earlier than did normal diploid lymphocytes after phytohemagglutinin stimulation as a whole, but that cycling trisomic and normal cells had the same mean cell cycle times. When exposed to gamma-rays or bleomycin in G0, trisomy 21 lymphocytes showed a 30% or, on average, 50% longer duration of cell turnover times, respectively, than normal cells; only bleomycin-treated trisomic cells had a biphasic dose-response. Frequencies of dicentrics and rings in first-division cells after gamma-ray or bleomycin exposure were twice as high in trisomic cells as in normal cells. The frequency of aberrations decreased by 50% (gamma-ray-exposed) or 65 to 85% (bleomycin-treated) through successive divisions; trisomic cells showed a more marked decline in aberration yields compared to normal cells after bleomycin treatment. These data support the idea that circulating lymphocytes in trisomy 21 patients have a shorter average life span or a younger average age.

Association of vitamin D receptor gene polymorphism with prostate cancer and benign prostatic hyperplasia in a Japanese population.

Recent studies have suggested that vitamin D is an important determinant of prostate cancer risk and inherited polymorphisms in the 3'-untranslated region (3'UTR) of the vitamin D receptor (VDR) gene are associated with the risk and progression of prostate cancer. This study was conducted to explore the association of VDR gene polymorphisms with prostate cancer risk in Japanese men who are considered to be much less influenced by environmental risk factors for prostate cancer. We studied 222 prostate cancer patients, 209 benign prostatic hyperplasia (BPH) patients, 128 male controls who were over 60 years old and without any evidence of prostate cancer or BPH, and 198 female controls. A PCR-RFLP method was used to determine three VDR gene polymorphisms in the 3'UTR characterized by restriction enzymes BsmI, ApaI and TaqI. In the BsmI polymorphism, heterozygosity or homozygosity for the absence of the BsmI restriction site was associated with one-third the risk of prostate cancer (P < 0.0001; odds ratio, 3.31; 95% confidence interval, 2.05-5.32) and with one-half the risk of BPH (P < 0.005; odds ratio, 2.07; 95% confidence interval, 1.33-3.22) compared with the male controls. The TaqI and ApaI polymorphisms did not show any significant association with either prostate cancer or BPH. The results indicate that the BsmI polymorphism in the VDR gene plays a significant role in protection against prostate cancer and BPH. Because of the racial difference in the strength of the linkage disequilibrium between the three polymorphisms, additional studies are required to apply the present results to other racial-ethnic groups.

Diet-induced alteration of fatty acid synthase in prostate cancer progression.

Fatty acid synthase (FASN) is a cytosolic metabolic enzyme that catalyzes de novo fatty acid synthesis. A high-fat diet (HFD) is attributed to prostate cancer (PCa) progression, but the role FASN on HFD-mediated PCa progression remains unclear. We investigated the role of FASN on PCa progression in LNCaP xenograft mice fed with HFD or low-fat diet (LFD), in PCa cells, and in clinical PCa. The HFD promoted tumour growth and FASN expression in the LNCaP xenograft mice. HFD resulted in AKT and extracellular signal-regulated kinase (ERK) activation and 5' adenosine monophosphate-activated protein kinase (AMPK) inactivation. Serum FASN levels were significantly lower in the HFD group (P=0.026) and correlated inversely with tumour volume (P=0.022). Extracellular FASN release was enhanced in the PCa cells with phosphatidylinositol 3-kinase (PI3K)/mitogen-activated protein kinase (MAPK) inhibition and AMPK signalling activation. FASN inhibition resulted in decrease of PCa cell proliferation through PI3K/MAPK downregulation and AMPK activation. Furthermore, AMPK activation was associated with FASN downregulation and PI3K/MAPK inactivation. Clinically, high FASN expression was significantly associated with high Gleason scores and advanced pathological T stage. Moreover, FASN expression was markedly decreased in the PCa response to androgen deprivation therapy and chemotherapy. HFD modulates FASN expression, which may be an important mechanism in HFD-associated PCa progression. Furthermore, a critical stimulatory loop exists between FASN and the PI3K/MAPK system, whereas AMPK signalling was associated with suppression. These may offer appropriate targets for chemoprevention and cancer therapy in HFD-induced PCa.

Utilization of native oxygen in Eu(RE)-doped GaN for enabling device compatibility in optoelectronic applications.

The detrimental influence of oxygen on the performance and reliability of V/III nitride based devices is well known. However, the influence of oxygen on the nature of the incorporation of other co-dopants, such as rare earth ions, has been largely overlooked in GaN. Here, we report the first comprehensive study of the critical role that oxygen has on Eu in GaN, as well as atomic scale observation of diffusion and local concentration of both atoms in the crystal lattice. We find that oxygen plays an integral role in the location, stability, and local defect structure around the Eu ions that were doped into the GaN host. Although the availability of oxygen is essential for these properties, it renders the material incompatible with GaN-based devices. However, the utilization of the normally occurring oxygen in GaN is promoted through structural manipulation, reducing its concentration by 2 orders of magnitude, while maintaining both the material quality and the favorable optical properties of the Eu ions. These findings open the way for full integration of RE dopants for optoelectronic functionalities in the existing GaN platform.

Reduced synthesis of 5-aminolevulinate dehydratase in styrene-treated rats.

5-Aminolevulinate dehydratase (porphobilinogen synthase; 5-aminolevulinate hydro-lyase, EC 4.2.1.24) preparations purified from rat liver and erythrocytes are indistinguishable in terms of molecular weight, subunit size, immunoreactivity, amino-acid composition and kinetic properties, suggesting that the enzyme from liver and erythrocytes are identical. Intraperitoneal injection of styrene to rats decreased 5-aminolevulinate dehydratase activity in both erythrocyte (to 8% of the control) and the liver (to 40% of the control). Studies utilizing polysome-directed cell-free translation indicated that hepatic synthesis of the enzyme was inhibited by styrene at the transcriptional level. In vitro addition of styrene 7,8-oxide, a major intermediate of styrene, to purified 5-aminolevulinate dehydratase resulted in a loss of immunoassayable enzyme protein to less than 1% of the untreated control. These findings suggest that the decrease in 5-aminolevulinate dehydratase caused by in vivo treatment of styrene is partially due to a transcription-dependent decrease in the enzyme synthesis, and partially to post-translational alteration of the structure of the enzyme protein.

Inhibition of delta-aminolevulinate dehydratase in trichloroethylene-exposed rats, and the effects on heme regulation.

A pronounced and irreversible depression of the erythroid and liver delta-aminolevulinate dehydratase (porphobilinogen synthase; 5-aminolevulinate hydro-lyase, EC 4.2.1.24) activity was observed in rats exposed to trichloroethylene, a widely used solvent. The depression could not be restored after the treatment with dithiothreitol and zinc; however, radioimmunoassay of delta-aminolevulinate dehydratase indicated that trichloroethylene exposure did not essentially decrease the amount of enzyme. The depression of the enzyme activity thus proved to be due not to a reduction in the enzyme amount but to enzyme inhibition. The purified holoenzyme (fully activated delta-aminolevulinate dehydratase with 1 atom zinc per subunit) and apoenzyme (fully activated enzyme with the remaining zinc less than 0.1 atom per subunit) were prepared to investigate the in vitro inhibition of the enzyme by trichloroethylene. Incubation with trichloroethylene did not inhibit the holoenzyme, but inhibited the apoenzyme dose-dependently. Trichloroethylene inhibited the holoenzyme when incubated with the mixed function oxidase system. The in vitro experiments reported here indicate two mechanisms of the enzyme inhibition by trichloroethylene. In the liver of rats exposed to trichloroethylene, cytochrome P-450 concentration and heme saturation of tryptophan pyrrolase (EC 1.13.11.11) are reduced; in addition, the activity of delta-aminolevulinate synthase (EC 2.3.1.37) increased. After exposure to trichloroethylene at 2.14 g/m3, urinary delta-aminolevulinic acid increased to 142% of the control, while the excretion of coproporphyrin was reduced to 19.6% of the control.

A novel locus, Mody4, distal to D7Mit189 on chromosome 7 determines early-onset NIDDM in nonobese C57BL/6 (Akita) mutant mice.

In this article, we report on a nonobese C57BL/6 (B6) mouse model of NIDDM named Akita mouse, characterized by early age onset and autosomal dominant mode of inheritance. At 7 weeks of age, the mean morning blood glucose levels (mmol/l) under ad libitum feeding conditions were significantly higher (P < 0.01, analysis of variance [ANOVA]) in diabetic mice than in unaffected mice: 27.3 +/- 5.3 for diabetic males (n = 50) and 9.3 +/- 1.2 for unaffected males (n = 50); 13.6 +/- 3.8 for diabetic females (n = 50) and 8.7 +/- 1.1 for unaffected females (n = 50), while corresponding immunoreactive insulin levels in plasma were significantly lower in diabetic mice than in unaffected mice. In vitro insulin secretion was also impaired, even at 4 weeks of age. The 50% survival time for male diabetic mice (305 days) was significantly shorter than that of unaffected counterpart mice but not for diabetic females. Obesity did not occur in diabetic mice. Histological examinations of the pancreas in diabetic mice, from 4 to 35 weeks of age, revealed decreases in the numbers of active beta-cells without insulitis. Morphometry demonstrated specific decreases in immunologically detectable insulin density in islets in diabetic mice, even at 4 weeks of age, without changes of relative islet areas. By linkage analysis, a single locus was identified on the basis of 178 N2 mice [(B6 x C3H/He)F1 x B6 and (B6 x C3H/He)F1 x C3H/He]. This locus, which we named Mody4, was mapped to chromosome 7 in a region 2-8 cM distal to D7Mit189 (logarithm of odds [LOD] score = 15.6 and 10.3).

A cluster of lysinuric protein intolerance (LPI) patients in a northern part of Iwate, Japan due to a founder effect. The Mass Screening Group.

Lysinuric protein intolerance is an autosomal recessive disease characterized by defective transport of the dibasic aminoacids. Mutational analysis of LPI patients in the northern part of Japan revealed that six were homozygous for the R410X mutation and two others were compound heterozygotes of R410X and other unknown mutations. In the population epidemiology study in a local cluster in the northern part of Iwate, ten heterozygotes were found in 1190 newborn babies leading to an estimated LPI incidence of 1/57,000. Polymorphism analysis revealed two major alleles, A and B, in intron 8. While the population frequency of allele A was 0.9 and that of allele B was 0.1 in the northern part of Japan the R410X mutations were exclusively on allele B in 31 chromosomes suggesting a founder effect. Genetic analysis in patients revealed strong linkage disequilibrium with D14S283 and TCRA indicating that the R410X mutation occurred before at least 130 generations ago (about 2600 years). The R410X mutation was shown to be useful as a molecular marker for screening LPI patients in the northern part of Japan.

Age-related decrease of growth hormone and prolactin gene expression in the mouse pituitary.

The effects of aging on pituitary GH, PRL, and alpha-tubulin messenger RNA (mRNA) levels were measured in 3-, 12-, and 27-month-old male C57BL/6J mice by dot-blot hybridization. The amount of GH and PRL mRNA in the pituitary deceased dramatically with age. However, total poly(A+) RNA (mRNA), as measured by hybridization with radioactively labeled oligo-(dT), was not altered during aging. In addition, there were no age-related changes in the level of alpha-tubulin mRNA. Thus, the effects of aging on GH and PRL mRNA levels are specific; the levels of the majority of cellular mRNAs are not altered with age. GH and mRNA levels decreased 35% between 3 and 12 months (P less than 0.05) and a total of 75% after 27 months (P less than 0.01). PRL mRNA levels decreased 65% between 12 and 27 months (P less than 0.01), although there was no significant decrease before 12 months. Whereas T3 is the most potent regulator of GH gene expression, we did not detect any significant age-related change in serum T3 levels. These results suggest that factors other than T3 play a role in the age-related decline in GH and PRL gene expression.

Developmental expression of proprotein-processing endoprotease furin in rat pancreatic islets.

The expression of furin in pancreatic beta-cells induces faster cell growth and a decrease in differentiated beta-cell-specific characteristics. During the development of rat pancreatic islets, the prohormone convertases, PC2 and PC3, appear during late gestation and are expressed long after birth. We investigated the developmental change in another yeast Kex2 family endoprotease, furin, in rat islets in relation to islet cell growth. Furin had appeared by gestational day 18 and was distributed in islets as well as exocrine tissues. The expression of furin in islets increased toward the neonatal stage. Bromodeoxyuridine (BrdU) incorporation was also elevated in the perinatal period. On postnatal days 10 and 20, staining characteristics were attenuated. On day 25, immediately after weaning, furin staining began to localize in the beta-cell region, and staining in the alpha-cell region became fainter. On day 270, the staining in the alpha-cell region disappeared, and staining in the beta-cell region remained positive, but was weaker. We conclude that furin expression was greatest during the perinatal period, when BrdU incorporation into islets was maximal. Furin expression continued, however, even after the BrdU incorporation decreased. Thus, furin appears to control the proliferation as well as differentiation of islet cells.

Decreased cellular proliferation by energy restriction is recovered by increasing housing temperature in rats.

We investigated the effects of life-prolonging energy restriction (ER) on body temperature (BT) and cellular proliferation in rats. Animals were fed either a control diet (C: 220 kJ/day) or an ER diet (110 kJ/day) from 7 weeks of age, and were housed at 20-22 degrees C. Another group of animals, fed on the ER diet, were transferred from 20-22 degrees C to a room at 30 degrees C (ER + I) at 20 weeks of age. The core body temperatures in individual animals were recorded over a 3-day period between 20 and 24 weeks of age. Cellular proliferation rates were quantitated by labeling S phase cells in the jejunum, epidermis, pituitary, and lung with bromodeoxy-uridine at 24 weeks of age. Long-term ER reduced the mean BT by 1 degree C, and reduced cellular proliferation in the jejunum, epidermis, pituitary, and lung. At 30 degrees C, the inhibitions were partially lifted in the examined organs except in the pituitary. Therefore, decreased cellular proliferation in the various organs after long-term ER in rats is lifted as it is in mice.