Stabilized phase-shifting fringe analysis by use of current-induced frequency modulation of laser diodes.

A closed-loop phase-shifting Fizeau-type interferometer was constructed that uses direct frequency modulation of a laser diode. The interferometer is servo controlled entirely in the phase domain, where optical phases are detected by two-frequency optical heterodyning. A detailed study of stabilization of the interferometer under feedback control was conducted both experimentally and theoretically. The interferometer showed good stability against vibration up to 200 Hz. The stabilization factors obtained experimentally are in good agreement with the theoretical calculations. The phase-shifting experiment was accomplished with high precision as well as with high stability against external disturbances. The profile measurement of a mirror surface was made with a phase-shifting analysis algorithm, and good measurement reproducibility of lambda/60 in the root-mean-square value was obtained for ten measurements within a period of 20 min.

Mutations of a human homologue of the Drosophila eyes absent gene (EYA1) detected in patients with congenital cataracts and ocular anterior segment anomalies.

The Drosophila eyes absent gene ( eya ) is involved in the formation of compound eyes. Flies with loss-of-function mutations of this gene develop no eyes and form the ectopic eye in the antennae and the ventral zone of the head on target expression. A highly conserved homo-logous gene in various invertebrates and vertebrates has been shown to function in the formation of the eye. In contrast, a human homologue, EYA1, has been identified by positional cloning as a candidate gene for branchio-oto-renal (BOR) syndrome, in which phenotypic manifestations are restricted to the areas of branchial arch, ear and kidney, with usually no anomalies in the eye. We have examined genomic DNA isolated from patients with various types of developmental eye anomaly for EYA1 mutations by the use of polymerase chain reaction-single-strand conformation polymorphism and sequencing. We identified three novel missense mutations in patients who had con-genital cataracts and ocular anterior segment anomalies. One of the patients had clinical features of BOR syndrome as well. This result implies that the human EYA1 gene is also involved in eye morphogenesis, and that a wide variety of clinical manifestations may be caused by EYA1 mutations.

[Sex differences in subjective well-being and related factors in elderly people in the community aged 75 and over].

Sex differences in factors related to subjective well-being were evaluated in people in their late old age by interviewing individuals aged 75 years and over living in 2 regions of Enzan City, Yamanashi Prefecture. The 17-item revised "Philadelphia Geriatric Center (PGC) Morale Scale" was used for evaluation of subjective well-being. Factors related to family status, employment, health related factors, activities of daily living, and results of physical examinations were each classified into two or more categories, and PGC Morale Scale points were compared among the categories for all subjects and separately for males and females using the Mann-Whitney test and the Kruskal-Wallis test. 1) Although the mean age of males (80.0 +/- 4.4 years) and females (80.4 +/- 4.3 years) was no significantly difference, PGC Morale Scale points were significantly higher in males than in females (p < 0.05), indicating a sex difference in subjective well-being. 2) In elderly females, subjective well-being was related to many factors, and there was a particularly strong relationship between subjective well-being and both health related factors and activities of daily living. 3) In elderly males, the factors related to subjective well-being were fewer than in females, consisting only of "social opportunities", "hobbies", and "grip strength". Since factors related to subjective well-being differ between the sexes, these differences must be taken into account when evaluating subjective QOL of the elderly.

Serum concentration of the pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP) is a useful indicator of decline and recovery of bone mineral density in lumbar spine: analysis in Japanese postmenopausal women with or without hormone replacement.

To reassess the clinical utility of serum pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP), a promising but controversial indicator of bone resorption, we evaluated its performance as a biochemical marker in a 6-month study of a strictly selected population of 76 Japanese postmenopausal and healthy women, 33 recipients of hormone replacement therapy and 43 nonrecipients. We measured bone mineral density (BMD) of the lumbar spine (L2-L4), and serum ICTP, carboxyterminal propeptide of type I procollagen (PICP) and other conventional serum biochemical markers, e.g. bone gla protein (BGP), alkaline phosphatase, calcium and phosphate at the entry and 6 months later. We calculated the percent change between the baseline and 6-month values (delta%) in lumbar BMD and the biochemical markers, individually, and compared the degree of correlations between delta% in BMD and that in the biochemical markers. Delta% in ICTP and delta% in BGP correlated with delta% in BMD negatively and significantly. Especially delta% in ICTP correlated with that in BMD to a high degree (P<0.0001). No significant correlation was observed in other biochemical markers. We concluded that serum ICTP is a sensitive and useful bone resorption marker in the postmenopausal population, which strongly correlates with the change in BMD.

No induction of chromosome aberrations in human spermatozoa exposed to extremely low frequency electromagnetic fields.

Clastogenic effects of extremely low frequency electromagnetic fields (ELF-EMFs) on human sperm chromosomes were studied using an interspecific in vitro fertilization system with zona-free golden hamster oocytes. Semen samples from healthy men were exposed to ELF-EMFs (50 Hz, 20 mT) for 2 h at 37 degreesC under 5% CO2 in air. The samples were then cryopreserved in liquid nitrogen for shipment to a cytogenetic laboratory. After thawing the samples, motile spermatozoa were collected using a continuous Percoll density gradient centrifugation and then capacitated for in vitro fertilization with hamster oocytes. Sperm-derived chromosomes were analyzed at first cleavage metaphase. The present experiment was performed twice using semen samples from two different donors. In test-1, incidence of spermatozoa that displayed structural chromosome aberrations was 17.0% (35/206) in the exposed group and 20.8% (55/264) in the control group. In test-2, structural chromosome aberrations were observed in 11.1% (13/117) of exposed spermatozoa and 13.8% (13/94) of spermatozoa in the control group. In both tests, there was no significant difference in the incidence of chromosomally abnormal spermatozoa between the exposed group and the control group. Types of aberrations observed and their incidences per spermatozoon in the exposed group were similar to those of the control group. Despite the small sample size, the present results suggest that ELF-EMFs have no clastogenic effect on human sperm chromosomes.

Bone metabolism after human parturition and the effect of lactation: longitudinal analysis of serum bone-related proteins and bone mineral content of the lumbar spine.

A prospective study was performed to investigate postpartum changes in human bone metabolism and the effects of lactation on them. The subjects consisted of two groups: 13 women who stopped breast-feeding within 3 months postpartum (short-term group) and 14 women who continued breast-feeding for more than 6 months postpartum (long-term group). Serum carboxyl-terminal propeptide of type I procollagen (PICP), carboxyl terminal cross-linked telopeptide of type I collagen (ICTP), and bone gla protein (BGP) were measured prepartum, and at 5 days, 1 month, 3 months and 9 months postpartum. Lumbar BMD was measured at 3-7 days, 3 months and 9 months postpartum. Between prepartum and 3 months postpartum, the values and variations in the markers were essentially the same in both groups. PICP was maintained at a constant and significantly higher level than the control value. In contrast, ICTP had increased markedly at 5 days postpartum, gradually decreasing thereafter. BGP was low prepartum and gradually increased. At 9 months postpartum, PICP and ICTP decreased to the control values in the short-term group. The postpartum time course of lumbar BMD showed a significant decrease in both groups at 3 months postpartum. Recovery to the puerperal level was seen at 9 months postpartum in the short-term group but not in the long-term group. In conclusion, bone resorption is stimulated by parturition as well as lactation resulting in postpartum loss of lumbar BMD.

[Relationship between knee pain and X-ray findings of osteoarthritis with reference to bone mineral density measured by computed X-ray densitometry].

We studied the relation between performance of activities of daily living and X-ray findings of osteoarthritis of the knee in aged persons. We made Covariance Structure Analysis models of knee pain, X-ray findings and bone mineral density as measured by computed X-ray densitometry. The subjects were 257 women aged from 47 to 88 years who were outpatients at an orthopedic clinic. The best-fit model indicated that loss of bone mineral density in metacarpals was associated with X-ray findings of knee-joint degeneration, as well as with knee pain. No relationship was found between knee-joint degeneration and knee pain. These results suggest that bone mineral density should be taken into consideration when interpreting X-ray findings of knee pain. This model incorporates the effects of degeneration of the subchondral bone. In summary, we should use measurements of bone mineral density along with X-ray findings for the diagnosis and treatment of knee osteoarthritis. We may be able to precisely predict knee pain caused by osteoarthritis, by analysis of a model that includes a lesion in joint cartilage.

Influence of pepsinogen gene polymorphisms on serum pepsinogen.

We identified pepsinogen C (PGC) gene polymorphisms by means of PCR, which amplified DNA in the region within the intron between exons 7 and 8, and by 6% polyacrylamide gel electrophoresis. Six alleles were found in a Japanese population. The frequencies of these alleles in 408 unrelated Japanese individuals were 0.074, 0.026, 0.335, 0.237, 0.016 and 0.314, respectively. The serum pepsinogen II level significantly decreased in the order of the allele 6 homozygote, the allele 6 heterozygote and the other genotypes (chi 2 = 7.850, D.F. = 2, p = 0.020). These findings indicated that the genetic background of serum pepsinogen should be considered when screening for stomach cancer by this procedure.

Distribution of apolipoprotein E gene polymorphisms in Japanese patients with Alzheimer's disease and in Japanese centenarians.

We have demonstrated an association between apolipoprotein E (apoE) gene polymorphisms and Alzheimer's disease (AD) in 163 Japanese patients by means of PCR. We found a significant increase in risk of nonfamilial AD for apoE allele epsilon4 in these individuals; this trend decreases with the increase in onset age. In centenarians, the distribution of apoE gene alleles is similar to that in the general population. The protective effect of allele epsilon2 against the development of AD is not statistically significant in our analysis. This indicates that apoE polymorphism is associated with AD regardless of race and that the age of onset is related to the apoE gene in the development of AD.

[Effect of measuring bone mineral density on calcium intake].

The diet in Japan has improved, but calcium intake has not increased for the past ten years, and it remains insufficient. To prevent osteoporosis, instruction in nutrition is directed at increasing calcium intake. We studied the effect of measuring bone mineral density on calcium intake in people receiving nutrition education. Intake of other nutrients was also measured. The subjects were 87 healthy women living in an agricultural region (Yamanashi Prefecture). They were members of a group formed to improve the diet of people in their area. For three days in October 1992 and in August 1994 food-weight records were obtained. A total of 76 of the 87 women chose to have their bone mineral density measured. The measurements before the first nutrition assessment in 1992. The intake of almost all nutrients tended to be greater in 1994 than in 1992. Calcium intake exceeded the minimum daily requirement (600mg). Calcium intake increased between 1992 and 1994 only in the subjects whose bone mineral density had been measured. Calcium intake decreased in the other subjects. Therefore, nutrition education programs aimed at preventing osteoporosis may be more effective if bone mineral density is measured. In addition, an appropriate balance of other nutrients can be maintained as the intake of calcium is increased.

[Association of cytochrome P-450 1A1 (CYP1A1) gene polymorphism to smoking status and hematologic findings].

Measures to control smoking are important in the field of preventive medicine. In order to clarify differences in susceptibility in individuals to lung cancer of genotypes of CYP1A1, which are considered to be related to lung carcinogenesis were evaluated in 391 healthy males to study relationship to smoking status and hematological findings. No correlation was observed between genotypes of CYP1A1 and smoking status. White blood cell counts in smokers with a Val allele were significantly higher than in those without a Val allele. Multiple regression analysis showed that the genotype of CYP1A1 and daily cigarette consumption had significant relationship with white blood cell count in smokers. However, red blood cell count, hemoglobin, hematocrit, MCV, MCH, or MCHC were not significantly associated with genotype of CYP1A1. There have been no previous reports on the relationship between the genotype of CYP1A1 and hematological findings. In consideration of the epidemiologic findings that many individuals with increased white blood cell counts have cancer or cardiac diseases, and reports that the increase in the white blood count was associated with poor respiratory function, white blood cell count may be candidate to for being a risk marker and thus contribute to prevention of these diseases.

Prevalence of dementia and distribution of ApoE alleles in Japanese centenarians: an almost-complete survey in Yamanashi Prefecture, Japan.

OBJECTIVE: To determine the prevalence and types of dementia in centenarians and to examine whether the ApoE epsilon 4 allele has significant impact on the development of Alzheimer's disease (AD) in the population. DESIGN: Cross-sectional study and a 6-month prospective study. SETTING: Yamanashi Prefecture, Japan. PARTICIPANTS: Forty-seven centenarians participated in the study to determine the prevalence and types of dementia. Thirty-three of the 47 participated in the study of ApoE genotyping. As controls, 224 demented older adults participated in the genetic study. Their age at onset was < 90 years. OUTCOMES: Prevalence of dementia based on DSM-III-R; types of dementia based on NINCDS-ADRDA and ICD-10; distribution on ApoE alleles in the centenarians and in the controls; and the 6-month mortality rate of the subjects. MAIN RESULTS: Of 47 centenarians, 70.2% had dementia, and AD accounted for the majority (75.8%) of the dementia cases. The distribution of ApoE alleles in all the subjects and the AD subjects was epsilon 2: 4.6% vs. 0%; epsilon 3: 90.1% vs. 94.1%; epsilon 4: 4.6% vs. 5.9%. The frequency of the epsilon 4 allele in the AD patients showed a tendency to decrease with increasing age, ranging from 38% for those with an age at onset of < 60 years to 22% for those with an age at onset of ranging from 80 to 89 years. The 6-month mortality rate was 27% (9/33) for the demented centenarians, whereas none of the 14 nondemented centenarians died. CONCLUSION: This almost-complete survey, conducted in a prefecture of Japan, revealed a high prevalence of dementia in centenarians. The ApoE epsilon 4 allele does not have an impact on the development of AD in centenarians.

Predictors of fall-related injuries among community-dwelling elderly people with dementia.

To determine the annual incidence of fall-related injuries among community-dwelling elderly people with dementia and to identify the factors predicting those likely to sustain such injuries, we conducted a cohort study with a one-year follow-up. As predicting factors, we paid particular attention to behavioural problems and difficulties in helping with activities of daily living based on the Assessment of Basic Care for the Demented (ABCD) scale. Thirty-five of 86 final study subjects and nine of 98 final control subjects sustained fall-related injuries. Significant factors associated with fall-related injuries to demented elderly subjects were ABCD score (adjusted odds ratio 0.73, 95% confidence interval 0.60-0.89), history of falls in the past year (3.65, 1.34-9.95), and Barthel index score (1.04, 1.00-1.08). This highlights the predictive value of better physical function but more difficult care status in relation to ADL for fall-related injuries.

[Effect of vitamin D receptor gene polymorphism and lifestyle on bone mineral density and bone mineral density decrement rate].

The effects of genetic and environmental factors on bone mineral density (BMD) were investigated in 108 healthy Japanese women. Of the 108 subjects, BMD (from the second to forth lumbar vertebrae) was measured in 1992 in 103, in 1993 in 100, and in both years in 95 by dual energy X-ray absorptiometry. Vitamin D receptor (VDR) gene polymorphism in intron 8 was used as a genetic marker. Information on menstruation, health status, lifestyle, quantities of nutrient intake and frequencies of food intake was obtained by questionnaire. The frequency of allele B (825bp), whose polymerase chain reaction (PCR) products cannot be cut with BsmI, was 0.259 and the frequency of allele b (650bp), whose PCR products can be cut with BsmI, was 0.741. The subjects in our study obeyed the Hardy-Weinberg law. While the frequency of allele B was 0.448 in European whites as reported by Morrison et al, it was 0.259 in our Japanese subjects, suggesting a racial difference. Z score values (average value 0, standard deviation 1) increased in the order BB, Bb and bb. This result indicates that allele B is associated with the lower BMD in Japanese, as in European whites. The BMD decrement rate increased in the order bb, Bb and BB, indicating that VDR gene polymorphism may be a regulatory factor for losing BMD. Most of lifestyle variables, calcium intake and vitamin D intake were not correlated with BMD, but the food frequency score (which was defined as values weighted in each of three food categories obtained by factor analysis) was significantly correlated with BMD. Multiple regression analysis showed significant influences of years after menopause, the food frequency score and VDR genotype on BMD. VDR genotype and years after menopause influenced the BMD decrement rate significantly in multiple regression analysis. Neither a relationship between BMD and calcium intake nor between BMD and vitamin D intake by VDR genotype was found. These results suggest that the VDR gene is a genetic factor in BMD and the BMD decrement rate in Japanese.

[Effects of pepsinogen C gene polymorphisms on serum pepsinogen I and serum pepsinogen II levels].

Recently pepsinogens have been considered to be effective markers of terminal differentiation of stomach mucosa, and also good markers of preneoplastic and neoplastic changes of the stomach mucosa. Not a few studies concerning polymorphisms of pepsinogen A and C genes have been reported, however, as far as the authors are aware, no study was performed as to the relation between polymorphisms and serum pepsinogen I and II levels. Polymorphisms of the pepsinogen C (PGC) gene were identified by PCR, which amplifies DNA in the region within the intron between exon 7 and exon 8, and 6% polyacrylamide gel (no urea) electrophoresis. Six alleles were observed in the Japanese population. Frequencies for these alleles in 221 unrelated Japanese individuals were 0.077, 0.036, 0.328, 0.240, 0.009 and 0.310, respectively. The association between the PGC genotype and serum pepsinogen was investigated. A higher serum pepsinogen II level was observed in individuals homozygous for allele 6 than in those with other genotypes. This result indicates that careful attention should be paid to the genetic background of serum pepsinogen in screening of stomach cancer by this method.

[Study on the association between risk factors for osteoporosis and bone mineral density].

The relationship between bone mineral density (BMD) and risk factors for osteoporosis was investigated on 146 females (23-68 years old) in Enzan city, Yamanashi prefecture. BMD was measured by DEXA (Dual Energy X-ray Absorptiometry) method. Information regarding menstruation, health status, life-style, quantities of nutrient intake and frequencies of food intake were obtained by questionnaire. Fitness level was determined by exercise test and daily energy expenditure by calorie-counter. The results were as follows; 1) No relationship between physical activities or daily energy consumption and BMD was found. 2) No relationship between calcium intake or vitamin D intake and BMD was found, but a significant and positive correlation coefficient between intake frequency of milk products and BMD was observed. 3) Significant influences of age, BMI, presence of lumbago and food frequency score on BMD were indicated by multiple regression analysis. Food frequency score were defined as values weighted in each of three food category, obtained by factor analysis. 4) Significant influences of height decrement rate per year and number of years postmenopausal on BMD reduction rate per year were indicated by multiple regression analysis. These results suggest that these significant factors are useful in indications of risk for osteoporosis.