Anomalous Separation of Small Y-Chromosomal DNA Fragments on Microchip Electrophoresis

We investigated an anomalous DNA separation where two DNA fragments from the human Y-chromosome sY638 (64 bp) and sY592 (65 bp), with only one base pair difference, were separated. This result is abnormal since in a previous study, we found that 5 bp was the minimum difference between two DNA fragments that the microchip electrophoresis system can separate. The formation of a mini-loop in the structure of the DNA fragment of sY638 (64 bp) was strongly expected to be the reason. To investigate this, we synthesized three modified DNA fragments for sY638 (64 bp), and the modifications were in two expected locations for possible mini-loop formation. Later, the separation between sY592 (65 bp) and the three modified fragments of sY638 (64 bp) was not possible. Thus, we conclude that the formation of a mini-loop in the structure of the DNA is the reason behind this anomalous separation.

Y chromosome haplogroup D2a1 is significantly associated with high levels of luteinizing hormone in Japanese men

The association between the Y chromosome haplogroup D2 and risk of azoospermia and low sperm motility has been previously studied, and it was indicated that haplogroups DE (YAP lineage) are associated with prostate cancer risk in Japanese males. Our assumption had been that Y chromosome haplogroups may be associated with sex hormone levels, because sex hormones have been deemed responsible for spermatogenesis and carcinogenesis. In this study, we assessed the association between Y chromosome haplogroups and sex hormone levels, including those of testosterone, sex hormone-binding globulin (SHBG), follicle-stimulating hormone (FSH), luteinizing hormone (LH), inhibin-B, and calculated free testosterone (cFT), in 901 young men from the general Japanese population (cohort 1) and 786 Japanese men of proven fertility (cohort 2). We found that the haplogroup D2a1 was significantly associated with high LH levels in a combined analysis involving two cohorts (β = 0.068, SE = 0.025, p = 0.0075), following correction for multiple testing. To date, this result is the first evidence that implicates Y chromosome haplogroups in an association with sex hormone levels.

Y chromosome gr/gr subdeletion is associated with lower semen quality in young men from the general Japanese population but not in fertile Japanese Men

Several case-control studies have investigated whether Y chromosome haplogroups or deletions are associated with spermatogenic failure. However, the relationships between Y chromosome haplogroups or deletions and semen quality in general population have not been elucidated. In this study, we assessed relationships between Y chromosome haplogroups or deletions and semen parameters in 791 fertile Japanese men and 1221 young men from the general Japanese population. We found that the haplogroup D2 (M55 lineage) was significantly associated with lower semen parameters, especially total motile sperm count (P = 0.00051, beta = -0.097), in men from the general population but not in fertile men. In addition, we found that the gr/gr subdeletion was associated with semen quality and in particular, strongly associated with decreased sperm motility (P = 0.00041, beta = -3.14) and total motile sperm count (P = 0.00031, beta = -0.099) in men from the general population but not in fertile men. The combined analysis of fertile Japanese men and men from the general Japanese population showed that the haplogroup D2 (M55 lineage) and the gr/gr subdeletion were strongly associated with reduced sperm motility (P = 0.00056, beta = -2.71, and P = 7.7 × 10(-5), beta = -3.05, respectively) and that haplogroup O2b1 was strongly associated with elevated sperm motility (P = 0.00089, beta = 2.94). These observations add further support for the view that the gr/gr subdeletion diminishes sperm motility that consequently may result in male infertility.

Impact of annual body mass index gain on obesity development in Japanese 6-year-old non-obese children

BACKGROUND

Effective timing of preventive intervention for adolescent obesity in non-obese school-aged children remains unclear. The aim of this study was to examine the impact of annual body mass index (BMI) gain on the development of adolescent obesity in 6-year-old non-obese Japanese children.

METHODS

Longitudinal weight and height data were collected annually from 9723 children aged 6-14 years, and individual per-year BMI gains were calculated. The BMI ≥ the 95th percentile for each age and sex defined obesity. In 6-year-old non-obese children, logistic regression analyses were applied to correlate the annual BMI gain at each age with obesity at a final survey.

RESULTS

The 6-year-old non-obese children who became obese at a final survey showed larger annual BMI gains at any age compared with their peers with respect to baseline BMI. Increases in annual BMI gain, even in early school age, raised the risk of adolescent obesity. Categorical analysis also showed that children aged 6-7 years with higher annual BMI gains than 1-SD above the mean had a significant risk for adolescent obesity (OR: 4.39 [95%CI: 2.98-6.46] in boys and 3.83 [95%CI: 2.60-5.63] in girls, respectively).

CONCLUSIONS

A larger annual BMI gain at any school age is a risk for adolescent obesity in 6-year-old non-obese children with no critical period. This suggests the need for earlier and continuous school-based surveillance using annual BMI gain for preventive intervention of adolescent obesity development.

Y chromosome haplogroup d2* lineage is associated with azoospermia in Japanese males

Several studies have investigated whether particular Y chromosome haplogroups are associated with spermatogenic failure in Japanese males; however, they produced differing results. In this study, to investigate the association of Y chromosome haplogroup with spermatogenic failure, we recruited 451 infertile patients and 730 fertile men from a Japanese population and typed their Y chromosome haplogroups. The infertile patients were suffering from varicocele, azoospermia, oligozoospermia, asthenozoospermia, obstructive azoospermia, karyotype abnormalities, microdeletions of the long arm of the Y chromosome, or other conditions that affect fertility. The frequency of haplogroup D2* was significantly higher (odds ratio = 2.28, 95% confidence interval = 1.44-3.61, P = 0.00034 using chi-square test) among the men with azoospermia than among the fertile men. None of the other Y haplogroups displayed associations with particular types of infertility. In conclusion, Y chromosome haplogroup D2* is associated with spermatogenic failure in Japanese males, suggesting that the Y chromosome lineage can have significant effects on spermatogenesis.

Climatic influence on the reproductive characteristics of Japanese males

We previously performed a survey of the sperm characteristics of the partners of pregnant women in four cities in Japan. In the present study, we analyzed the sperm characteristics of these subjects and the correlations between these sperm characteristics and climatic changes or Y chromosome haplogroups. Our results showed that more haplogroup D2a1 males than O2b1 males were born in the first half of the year (January to June), whereas more O2b1 males were born in the last half of the year (July to December) (P<0.05). This was agreed and correlated with the seasonal variations in their mean sperm concentrations. The haplogroup C, D* and D2a1 males displayed lower sperm concentrations from March to May, followed by an increase in their sperm concentrations starting in June or July, while the O2b1 males displayed higher sperm concentrations in the first half of the year followed by a sudden decrease from July to August (P<0.05). We hypothesize that the Japanese climate has different effects on the sperm characteristics and reproductive seasonality of males from different lineages; and therefore, has influenced the modern population of Japan.

Correlations between genetic variance and adiposity measures, and gene x gene interactions for obesity in postmenopausal Vietnamese women

Although environmental factors are important, there is considerable evidence that genes also have a significant role in the pathogenesis of obesity. We conducted a population-based study to investigate the relationship between candidate genes for obesity (UCP1, UCP2, ADRA2B, ADRB3, LEPR, VDR and ESR1) and adiposity measures (body mass index, body fat percentage, weight, waist circumference and waist-hip ratio) in terms of individual gene and gene x gene interaction in models unadjusted and adjusted for covariates (age, years since menopause, educational level and total energy intake). Postmenopausal women with TC genotype of ESR1 gene had higher body fat percentage than those with TT genotype in the models unadjusted and adjusted for the covariates (P = 0.006 in adjusted model). In multiple logistic regression analysis, BsmI and ApaI SNPs of VDR genes were significantly associated with overweight and obesity. The UCP2-VDR ApaI interaction to susceptibility of overweight and obesity was first observed from logistic regression analysis, and then confirmed in the multifactor dimensionality reduction method unadjusted and adjusted for the covariates. This interaction had 69.09% prediction accuracy for overweight and obesity (P = 0.001, sign test). In conclusion, the study suggests the significant association of ESR1 and VDR genes with adiposity measures and the UCP2-VDR ApaI interaction to susceptibility to being overweight and obesity in postmenopausal Vietnamese women.

Gastrointestinal dysmotility is associated with altered gut flora and septic mortality in patients with severe systemic inflammatory response syndrome: a preliminary study

BACKGROUND

The gut is an important target organ for injury after severe insult, and resolution of feeding intolerance is crucial for critically ill patients. We investigated gut flora and motility to evaluate the impact of gastrointestinal dysmotility on septic complications in patients with severe systemic inflammatory response syndrome (SIRS).

METHODS

Sixty-three ICU patients with severe SIRS were divided into two groups depending on their intestinal condition. Patients with feeding intolerance comprised patients who had feeding intolerance, defined as ≥ 300 mL reflux from nasal gastric feeding tube in 24 h, and patients without feeding intolerance comprised patients with no feeding intolerance. We compared fecal microflora, incidences of bacteremia, and mortality between these groups.

KEY RESULTS

Analysis of feces showed that patients with feeding intolerance had significantly lower numbers of total obligate anaerobes including Bacteroidaceae and Bifidobacterium, higher numbers of Staphylococcus, lower concentrations of acetic acid and propionic acid, and higher concentrations of succinic acid and lactic acid than those in patients without feeding intolerance (P ≤ 0.05). Patients with feeding intolerance had higher incidences of bacteremia (86%vs 18%) and mortality (64%vs 20%) than did patients without feeding intolerance (P ≤ 0.05).

CONCLUSIONS & INFERENCES

Gut flora and organic acids were significantly altered in patients with severe SIRS complicated by gastrointestinal dysmotility, which was associated with higher septic mortality in SIRS patients.

Determinants of life satisfaction among Japanese elderly women attending health care and welfare service facilities

Prolonged life expectancy must be recognized as an excellent achievement of modern medicine, but not all the elderly people are satisfied with their lives. Life satisfaction is a multi-dimensional issue that depends on many objective and subjective characteristics. In this study, we aimed at investigating the factors affecting life satisfaction of 314 elderly Japanese women attending in 28 elderly-care and welfare facilities at Tokushima Prefecture, Japan. Our results indicated that elderly subjects with depression tendencies always show significantly lower degrees of life satisfaction than others who are not depressed (p<0.001) regardless of their cognitive status. Furthermore, elderly women who shared decision for their living place and whose opinions were considered for daily life decisions reported significantly more life satisfaction levels than others. We conclude that elderly life satisfaction is affected by various determinants however, with different influencing weight. Life satisfaction of elderly people, with or without dementia, is greatly affected by their mood status and share in decision making. Avoiding elderly people depressive mood, sharing them in various daily decisions, considering their opinions, and allowing them to decide their elderly-care facility placement are crucial determinants for their life satisfaction and essential for their coping, adaptation, well-being and successful aging.

Prediction of Japanese children at risk for complications of childhood obesity: gender differences for intervention approaches

Childhood obesity is one of the most serious public health problems in Japan, especially in Tokushima compared with other prefectures. This study was designed to clarify the life habits which predispose to development of obesity and can be modified through an appropriate intervention program to combat childhood obesity and its lifestyle-related diseases. A total of 216 school children from Itano Town, a municipality of Tokushima Prefecture, Japan, who are attending the fourth grade (9-10 years) of elementary schools, participated in the study from 2004 to 2007. The study included child's life habits questionnaire, investigating physical activity by recording the daily steps using a pedometer, anthropometric measurements, hematological examination and hemodynamometry in a cross-sectional survey during a two-month period from June to July every year. We conclude that there are considerable gender-related differences for developing obesity and other lifestyle-related diseases; and all intervention strategies against obesity must consider such gender differences. For example, restriction of television watching hours must be intervened for controlling obesity in boys, however for girls, promotion of exercise practice or making more steps per day with adequate sleeping periods should be intervened as the proper approaches for preventing and controlling obesity and other lifestyle-related diseases.

Proteasome activity correlates with male BMI and contributes to the differentiation of adipocyte in hADSC

We have previously reported that 26S proteasome subunit mRNA expressions correlate with male body mass index (BMI). In this study, to investigate whether proteasome activities are correlated with BMI, we recruited 61 healthy young Japanese male subjects, measured proteasome activities in their plasma, and correlated them with their BMI and various metabolic factors. We found that among three different proteasome activities, chymotrypsin-like activity in plasma was positively correlated with BMI in healthy Japanese male subjects. Furthermore, we analyzed proteasome activity in vitro during the differentiation of human adipose-derived stem cell (hADSC) into mature adipocytes. In the early stage of differentiation, proteasome activity was at its highest level, and proteasome inhibitor could inhibit hADSC adipocyte differentiation. Our findings suggest that proteasome is an important controlling factor for the development of obesity and adipogenesis.

The male-determining gene SRY is a hybrid of DGCR8 and SOX3, and is regulated by the transcription factor CP2

In mammals, sex is determined by the presence or absence of the Y chromosome that bears a male-dominant sex-determining gene SRY, which switches the differentiation of gonads into male testes. The molecular signaling mechanism turning on the switch, however, has remained unclear for 18 years since the identification of the gene. Here, we describe how this gene emerged and started to work. From amino acid homology, we realized that SRY is a hybrid gene between a portion of the first exon of DiGeorge syndrome critical region gene 8 (DGCR8) and the high-mobility group (HMG) box of SRY box-3 (SOX3) gene. We identified the regulatory sequence in the SRY promotor region by searching for a common motif shared with DGCR8 mRNA. From the motif search between DGCR8 mRNA and the SRY upstream sequence, we found that the transcription factor CP2 (TFCP2) binding motif is present in both. TFCP2 overexpression did not show a significant increase of SRY mRNA expression, and TFCP2 suppression by RNA interference (RNAi) significantly reduced SRY mRNA expression. Furthermore, electrophoretic mobility shift assay (EMSA) demonstrated that TFCP2 acts as a regulator by directly binding to the SRY promoter. We conclude that SRY is a hybrid gene composed of two genes, DGCR8 and SOX3; and TFCP2 is an essential transcription factor for SRY expression regulation.

Proteasome subunits mRNA expressions correlate with male BMI: implications for a role in obesity

Obesity as well as its associated chronic diseases and adverse health consequences such as type 2 diabetes mellitus, dyslipidemia, hypertension, and coronary artery disease are afflicting middle-aged adults and an ever greater number of children globally. We planned to investigate new obesity-related factors using proteomics approaches in a randomly selected three high and three low BMI samples of Epstein-Barr-transformed B (EBV-B) lymphoblastoid cell lines prepared from two groups of young Japanese men with different BMI. To search novel obesity-related factors, comparisons of protein expressions between high and low BMI groups were carried out by two-dimensional gel electrophoresis (2-DE). Gene transcripts of proteasome subunits found out from 2-DE were further determined by quantitative real-time PCR. Results from proteomics approach showed that the expression of proteasome alpha subunit type 5 (PSMA5) was significantly lower in the high BMI male group than in those with low BMI (P < 0.05). To validate these results, we expanded the study to include 20 more men and used real-time PCR to quantify the mRNA expression level in their EBV-B cells. Both PSMA5 and PSMA2 of EBV-B cells showed negative correlation with BMI. Furthermore, the mRNA levels measured in the peripheral blood B lymphocytes for many proteasome subunits in 75 healthy men and women showed significant negative correlation with BMI in healthy men. Our findings suggest that proteasome expression may play a key role in obesity.

[An approach to prevent lifestyle-related diseases of children in collaboration with various organizations in Tokushima]

OBJECTIVE

To support the goal of "Lifetime health promotion from childhood", a Committee for Strategies to Prevent Lifestyle-related Diseases was established as part of the Tokushima Prefecture Medical Association in 2000. In this report, we present the activities of this committee, in collaboration with various organizations such as schools, a medical association, health administrators and universities.

ACTIVITIES

In 2000, a physical survey was performed for all students in primary and junior high schools in Tokushima prefecture. Subsequently, a software program for determining the degree of obesity using the standard body weight of Tokushima children was produced. In 2001, the committee conducted a survey concerning measures taken against lifestyle-related diseases by each organization. In 2003, a "Health management system for obesity in children" and a "School urine examination system" were established to identify high-risk students who should be taken to consult primary physicians. These medical intervention systems have allowed continuous calculation of real numbers and actual status of problems with overweight and obese children. Moreover, we performed lifestyle habit surveys among about 3000 students and produced manuals for population-based approaches.

RESULTS

Compared with nationwide values, there was no difference in height, but the weight and BMI (Body Mass Index) of Tokushima students were larger. The survey concerning measures against lifestyle-related diseases clarified the present status of school health committees, staffing available to provide individual/nutritional guidance and the execution rate of collaborative projects in each organization. The intervention systems for visits to primary physicians have continued to show almost constant consultation rates. Approximately 80% of severely obese children had at least one medical problem. The lifestyle habits survey did not identify any marked differences in children of Tokushima Prefecture compared with nationwide values, except for a slightly earlier waking-up time. However, this survey demonstrated differences in lifestyle habits according to the body physique, and a relationship between eating meals with the family and other lifestyle habits. The numbers of overweight and severely obese children in Tokushima have been decreasing since the peaks of 2001 and 2002.

CONCLUSIONS

Activities to prevent lifestyle-related diseases from childhood have continued in collaboration with various organizations in Tokushima. The prefecture-wide physical surveys and high-risk intervention strategies might have had good social effects in Tokushima. As a result, the number of obese children may be decreasing.

Interrelationship of dipeptidyl peptidase IV (DPP4) with the development of diabetes, dyslipidaemia and nephropathy: a streptozotocin-induced model using wild-type and DPP4-deficient rats

We examined the role of dipeptidyl peptidase IV (DPP4) in the development of diabetes, dyslipidaemia and renal dysfunction induced by streptozotocin (STZ). F344/DuCrlCrlj rats, which lack DPP4 activity, and wild-type rats were treated with STZ. Plasma DPP4 activity and biochemical parameters were measured until 42 days after STZ treatment. At the end of the experiment, renal function and DPP4 expressions of the kidney, liver, pancreas and adipose tissues were determined. Increases in blood glucose, cholesterol and triglycerides were evoked by STZ in both rat strains; however, the onset of hyperglycaemia was delayed in DPP4-deficient rats as compared with wild-type rats. By contrast, more severe dyslipidaemia was observed in DPP4-deficient rats than in wild-type rats after STZ treatment. Plasma DPP4 activity increased progressively with time after STZ treatment in wild-type rats. The kidney of wild-type rats showed decreased DPP4 activity with increased Dpp4 mRNA after STZ treatment. In addition, kidney weight, serum creatinine and excreted amounts of urinary protein, glucose and DPP4 enzyme were enhanced by STZ. DPP4-deficient rats showed increased serum creatinine in accordance with decreased creatinine clearance as compared with wild-type rats after STZ treatment. In conclusion, plasma DPP4 activity increased after STZ treatment, positively correlating to blood glucose. DPP4-deficient rats were resistant to developing diabetes, while susceptible to dyslipidaemia and reduction of glomerular filtration rate by STZ. DPP4 activation may be responsible for hyperglycaemia, lipid metabolism and preservation of renal function.

Effects of lifestyle habits and eating meals together with the family on the prevalence of obesity among school children in Tokushima, Japan: a cross-sectional questionnaire-based survey

Obesity in children has become a major global public health concern. The prevention of obesity must start from early childhood in order to establish sound lifestyle habits and promote healthy adulthood. In this study, we evaluated factors associated with the prevention of obesity and the development of healthy lifestyle habits in children. A cross-sectional, questionnaire-based survey was performed in elementary and junior high school students in Tokushima Prefecture, Japan, during the summer of 2004. The questionnaire consisted of 30 items such as physique, sleep, eating habits, diet, exercise, free time, and attending after-school lessons. Our study revealed that eating meals as a family every day is associated with a lower rate of obesity as well as getting good lifestyle habits such as eating balanced meals and getting enough sleep. Of the 3,291 students who responded to the questionnaire, 2,688 (81.7%) reported that they eat meals with their family every day. The percentage of students who eat meals with their family every day decreased with increasing school grade, with the lowest percent in the junior high school students. However, the results regarding female junior high school students revealed a marked association between eating meals with the family every day and good lifestyle habits. We recommend that parents and school teaching staff encourage the establishment of sound, healthy lifestyle habits in children from early childhood as an effective measure for the prevention of obesity.

Overexpression of SOX15 inhibits proliferation of NT2/D1 cells derived from a testicular embryonal cell carcinoma

SOX (Sry-related HMG box) family proteins, which have an evolutionarily conserved DNA binding domain, have crucial roles in cell differentiation. However, their target genes remain enigmatic. Some members of the SOX family may have roles in regulation of cell proliferation. We established stable NT2/D1 cell lines overexpressing SOX15 (SOX15-NT2/D1), and a modified 3-(4,5-dime-thylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that the SOX15-NT2/D1 cells exhibited significantly slower growth than the controls. Flow cytometry analysis revealed that an increased fraction of the SOX15-NT2/D1 cells were in G1-G0. In addition, a microarray analysis identified 26 genes that were up-regulated in the SOX15-NT2/D1 cells, but none that were down-regulated genes. Among the up-regulated genes, IGFBP5, S100A4, ID2, FABP5, MTSS1, PDCD4 have been shown to be related to cell proliferation and/or the cell cycle.

Prevalence of metabolic complications in children with severe obesity

BACKGROUND

The purpose of the present paper was to clarify the prevalence of metabolic complications in severely obese children.

METHODS

The subjects of the present study were 367 severely obese Japanese children in Tokushima, who were more than 150% of the standard weight for their sex and height (school grades 1-9; age range, 6-16 years). Data concerning anthropometric and metabolic parameters (body fat %, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, uric acid, blood glucose, serum insulin, alanine aminotransferase, and blood pressure) were analyzed.

RESULTS

The prevalence of each abnormality in obese children was high compared with that in the general population. Metabolic variables were correlated with each other. A total of 80.4% of severely obese children had at least one complication.

CONCLUSION

Severely obese children have various metabolic abnormalities even during their early school years. Intervention by primary physicians in cooperation with schools is needed for the prevention of lifestyle-related diseases.

Correlation of month and season of birth with height, weight and degree of obesity of rural Japanese children

Month and season of birth are thought to influence height, weight and degree of obesity in schoolchildren. A cross-sectional study was designed to measure the height and weight of all children aged 6-15 years attending primary and junior high schools in Tokushima Prefecture, Japan. Data were standardized (z-scores) and analysed separately by gender and age. The mean z-score for height and weight were the highest in subjects born during the months of spring and the lowest in those born during the months of winter (p < 0.0001), whereas the means were significantly higher in children born during the months of summer than in those born during the months of autumn (p < 0.0001). A gradually decreasing trend of height and weight was observed in children of both genders born between May and Mar (from spring to winter). There was no significant difference in degree of obesity among the four seasons of birth for boys and girls. The highest prevalence of obese boys have born during spring (among 6-year-old boys) and summer (among 7-year-old boys), whereas the highest prevalence of obese girls have born during spring (among 6-year-old girls) and winter (among 10-year-old girls). Our findings suggest that month and season of birth influence height and weight of schoolchildren in Tokushima but not their degree of obesity.

Y chromosomal STRs haplotypes in two populations from Bolivia

In the present study, we typed our previously reported two microsatellite markers, DXYS241 and DXYS266 together with a basic set of nine Y-STRs (DYS19, DYS389I/II, DYS390, DYS391, DYS392, DYS393, DXYS156Y, DYS413) on Y chromosomes from two Bolivian populations. Unrelated males from communities living at high- (N=59) and low- (N=142) altitude, were studied. Combining the alleles into 11 Y-STRs haplotypes revealed that the high-altitude population is significantly less diverse than the low-altitude population. Haplotype diversities of 0.927+/-0.029 and 0.996+/-0.002 were found within the high-altitude, and the low-altitude populations, respectively. Within the high-altitude population 40 haplotypes were detected, whereas in the low-altitude population 113 haplotypes were found. Only three haplotypes were shared between both populations. Haplotyping-based discrimination using the 11 Y-STRs including our new two microsatellite markers DXYS241 and DXYS266 was shown to be powerful than using the conventional 9 Y-STRs, especially for the low-altitude Bolivian population. This 11 Y-STRs-based haplotyping system shows a very high potential for discrimination and could provide an ideal tool for forensic analysis and population studies. Moreover, this study includes data about two Bolivian populations which were not previously reported, this will help in building a world-wide database for future use in forensic and legal studies.

Altered expression pattern of heat shock transcription factor, Y chromosome (HSFY) may be related to altered differentiation of spermatogenic cells in testes with deteriorated spermatogenesis

OBJECTIVE

To evaluate the expression patterns of heat shock transcription factor, Y chromosome (HSFY), in the testes showing deteriorated spermatogenesis.

DESIGN

Prospective study.

SETTING

University hospital, its branch hospital, and academic laboratory.

PATIENT(S)

Men undergoing testicular biopsy for the investigation of infertility and men undergoing orchiectomy for testicular cancer.

INTERVENTION(S)

After pathologic evaluation, specimens were subdivided into three groups: normal spermatogenesis (n = 8), maturation arrest (n = 5), and Sertoli cell-only syndrome (n = 4). Immunostaining and Western blotting techniques determined the expression of HSFY.

MAIN OUTCOME MEASURE(S)

Expression of HSFY in testes.

RESULT(S)

Western blotting data revealed HSFY in the testicular tissues with normal spermatogenesis, maturation arrest, and Sertoli cell-only syndrome, but the amount of the protein in the maturation arrest and Sertoli cell-only syndrome samples was altered. The immunohistochemical data demonstrated that HSFY was expressed in spermatogenic cells and Sertoli cells in all specimens. However, the expression of HSFY was low or absent in spermatogenic cells of maturation arrest specimens, and the ratio of HSFY expressed in Sertoli cells was different in the specimens with maturation arrest and with Sertoli cell-only syndrome.

CONCLUSION(S)

Altered expression of the HSFY in the testis showing deteriorated spermatogenesis may be associated with alteration of spermatogenic cell differentiation.

Lack of association between the incidence of testicular germ cell tumors and Y-chromosome haplogroups in the Japanese population

BACKGROUND

Despite being relatively uncommon, testicular germ cell tumors (TGCT) are the most common malignant disease in young men. Epidemiological studies concerning patients with testicular cancer indicate that the most of them have poor semen quality or testicular dysgenesis. However, many studies have shown that the Y chromosome harbors many candidate genes responsible for spermatogenesis process and development and maintenance of the germ cells. The Y chromosome is thought to have a relationship with the formation and progression of TGCT.

MATERIALS AND METHODS

To verify this relationship, we investigated if there is any correlation between the Y chromosome structural variations presented as different haplogroups and the occurrence of TGCT in the Japanese population. Using combined haplogroups based on typing of three Y chromosome polymorphic binary markers, we analyzed 68 TGCT derived from Japanese patients together with randomly selected 104 unrelated healthy Japanese matched male controls who were confirmed as residents of the same geographic area.

RESULTS

Our findings showed a lack of association between the incidence of TGCT and the different Y- chromosome haplogroups in Japanese population.

CONCLUSION

We concluded that there are no significant variations in males from different Y chromosome lineages regarding their susceptibility or resistance for developing TGCT. The previously hypothesized role of the Y chromosome in the development of TGCT is still uncertain and needs further verification.

Association of estrogen receptor alpha gene polymorphisms and lifestyle factors with calcaneal quantitative ultrasound and osteoporosis in postmenopausal Vietnamese women

Genetic and lifestyle factors are important in the pathogenesis of osteoporosis. We investigated the relationships of PvuII and XbaI polymorphisms of the estrogen receptor alpha (ER-alpha) gene, lifestyle factors with speed of sound at the calcaneus (calcaneal SOS) and osteoporosis in a population-based study of 140 healthy postmenopausal women. By an analysis of covariates, women with higher copies of P or X alleles had higher calcaneal SOS compared with others (P=0.012, PP vs. pp; P=0.045, Xx vs. xx). Women with lower copies of px or higher copies of PX haplotypes had higher calcaneal SOS compared with others (P=0.021, 0 px vs. 2 px; P=0.011, 1 PX vs. 0 PX). The px and PX haplotypes, age and years since menopause were found to be independent predictors of calcaneal SOS in multiple linear regression models. Using logistic regression, we found an increased osteoporosis risk with evidence for a px haplotype dose effect (OR=2.82, 95% CI=1.50-5.31, P=0.001) and for a PX haplotype dose effect (OR=0.42, 95% CI=0.19-0.93, P=0.033). An increased educational level was associated with a reduced risk of osteoporosis (P=0.035 in the model with px, P=0.044 in the model with PX). In conclusion, the present study suggests that PvuII and XbaI polymorphims of the ER-alpha gene, age, years since menopause and educational level are associated with bone density, as assessed by calcaneal SOS, and osteoporosis in postmenopausal Vietnamese women.

Rapid multiplexing and simultaneous detection of human spermatogenetic failure with a 12 lane microchip electrophoresis system

For the amplification and ultrafast separation of the genetic markers and DNA sequences that are related to human male infertility, a multiplex PCR for amplifying three DNA sequence-tagged sites (STS) located on the human Y chromosome with possible roles in the spermatogenesis process has been designed and applied followed by separation on a microchip. First, the optimum T(m) degree for the three DNA markers was optimized and determined experimentally, and the three DNA STS were amplified. These three DNA markers were then separated on a 12-lane microchip electrophoresis system, which can analyze the DNA markers on 12 channels simultaneously. The combination of these two technologies, multiplex PCR and microchip electrophoresis, allows the analysis of 36 DNA markers (12x3) within only 180 s.

Expression analysis of a mouse orthologue of HSFY, a candidate for the azoospermic factor on the human Y chromosome

Heat shock transcription factor on Y (HSFY) is located in one of three candidate regions for azoospermic factor (AZF), AZFb on the Y chromosome. We and others have already revealed that some azoospermic males are missing the regions of the Y chromosome including HSFY. Previously, we showed that murine HSFY-like sequence [mHSFYL (Riken cDNA 4933413G11Rik)], which is the mouse orthologue of HSFY, is exclusively expressed in testis. The sequences encoding the presumed DNA-binding domain in HSFY and mHSFYL were found in other mammals such as dogs, cows and chickens. To elucidate mHSFYL expression in the testes in detail, we carried out in situ hybridization. mHSFYL was predominantly expressed in round spermatids. Furthermore, we clarified the intracellular distribution of mHSFYL in COS1 cells with HA- or GFP-tagged proteins. Both HA-mHSFYL and GFP-mHSFYL were located in the nucleus. Our results suggest that HSFY/mHSFYL may have evolutionarily conserved functions for spermatogenesis.

Prostate cancer incidence varies among males from different Y-chromosome lineages

The incidence rate of prostate cancer in African-American males is two times higher than Caucasian men and ten times higher than Japanese men. The geographical specificity of Y haplogroups implies that males from different ethnic groups undoubtedly have various Y lineages with different Y-chromosomal characteristics that may affect their susceptibility or resistance to such a male-specific cancer. To confirm this hypothesis we studied the Y-chromosomal haplogroups of 92 Japanese prostate cancer patients comparing them with randomly selected 109 unrelated healthy Japanese male controls who were confirmed to be residents of the same geographical area. Males could be classified using three binary Y-chromosome markers (sex-determining region Y (SRY), YAP, 47z) into four haplogroups DE, O2b(*), O2b1, and untagged group. Our results confirmed that prostate cancer incidence varies among males from different Y-chromosome lineages. Males from DE and the untagged haplogroups are at a significantly higher risk to develop prostate cancer than O2b(*) and O2b1 haplogroups (P=0.01), odds ratio 2.17 and 95% confidence interval (1.16-4.07). Males from haplogroup DE are over-represented in the patient group showing a percentage of 41.3%. The underlying possible causes of susceptibility variations of different Y lineages for such a male-specific cancer tumorigenesis are discussed. These findings explain the lower incidence of prostate cancer in Japanese and other South East Asian males than other populations. To our knowledge, this is the first reliable study examining the association between prostate cancer and Y-chromosomal haplogroups, comparing prostate cancer patients with carefully selected matched controls.

Surfactant protein B gene variations and susceptibility to lung cancer in chromate workers

BACKGROUND

Hexavalent chromium has been extensively investigated regarding its mutagenicity and carcinogenicity; however, its mechanism for initiating and enhancing the development of lung cancer is still obscure. Biomarkers of exposure, effect or susceptibility are required for risk assessment and for epidemiologic research studies especially in occupational settings. Since the surfactant protein system (SP) is very important for normal lung function and for mediating local airway conditions and in the clearance of the upper respiratory tract from the occupational and environmental dusts, we hypothesize that SP genes may represent good candidates to study susceptibility for lung cancer.

METHODS

Using PCR genotyping methods with gel electrophoresis and confirmation of results with precise DNA fragment size measurement on microchip electrophoresis, we analyzed SP-B intron-4 polymorphism in 230 subjects who were classified into groups; chromate-related lung cancer, control chromate workers who had not developed lung cancer, control individuals with non chromate-related adenocarcinoma or squamous cell carcinoma of the lungs, or healthy Japanese control individuals.

RESULTS

Our results indicated that the SP-B variants (deletion/insertion) were significantly overrepresented (61.3%) in the chromate-related lung cancer group than other groups (X2 = 47.6; DF = 4, P = 0.0001). There was a significant difference between the chromate lung cancer group and both of the control groups, healthy individuals and chromate workers who did not develop lung cancer, showing odds ratios (OR) with 95% confidence intervals (CI) of 21.9 (7.3-65.7) and 19.0 (3.78-95.4), respectively. Compared with 46 non chromate-related SCC of the lung, the SP-B variants were significantly overrepresented in the chromate-related SCC (18/28; 64.3%) than the non-chromate SCC (11/46; 23.9%) of the lung samples (X(2) = 10.27, P = 0.01), OR with 95% CI is 5.73 (2.05-16.01).

CONCLUSION

These findings indicate a very strong association of the SP-B intron-4 variants with mechanisms that may enhance lung cancer susceptibility, especially in workers who are employed in chromate industry. Moreover, confirmation of such results may help to suggest adding the SP-B intron-4 typing to be one of the screening tests of the pre-placement medical examination to confirm that the worker has no variations of the SP-B gene before being engaged in a chromium-related industry, with the intention of providing proper medical counseling.

[An evaluation of teaching objectives for seminars and clerkship of social medicine in medical schools in Japan]

OBJECTIVES

The purpose of this study was to evaluate the curriculum of seminars and clerkship for social medicine in medical schools in Japan, with special reference to teaching objectives.

METHODS

A survey was conducted in December, 2002 by sending questionnaires to all the member departments of the Conference for Hygiene and Public Health Teaching in Medical Schools in Japan. Teaching objectives for seminars and clerkship of social medicine stated in their curricula were analyzed by frequencies of key words related to learner's "Knowledge, Attitude, and Behavior". Also, five professors of public health independently rated the stated teaching objectives using nine evaluation criteria divided into three levels and mean ratings were obtained.

RESULTS

Although 80% of the schools described their General Instructional Objectives (GIOs), only 63% of the universities stated Specific Behavioral Objectives (SBOs). Evaluation of the contents of the descriptions revealed that, although many courses described the GIOs with the student as subjective, only a small number of courses mentioned "Attitude and Behavior" in SBO. Also, many courses did not make any apparent distinction between GIOs and SBOs.

CONCLUSIONS

Practical training is a crucial component in medical education and seminars and clerkship play an important role in teaching social medicine to medical students. However, the present study revealed that many medical schools in Japan do not have adequately defined teaching objectives. Improvement of the curricula in courses of social medicine is required with particular reference to specific behavioral objectives and goals for seminars and clerkship.

A/G heterozygote of the A-3826G polymorphism in the UCP-1 gene has higher BMI than A/A and G/G homozygote in young Japanese males

UCP-1 is suggested to have important roles for thermogenesis and energy expenditure. To elucidate whether the A-3826G polymorphism that is located in the 5' flanking region of the UCP-1 gene has roles in healthy young people, the polymorphism was genotyped among 251 young Japanese men whose mean age is 22.7 years old. We analyzed relationship between the A-3826G polymorphism and body mass index (BMI) or six biochemical parameters, serum concentration of total cholesterol (TC), high density lipoprotein (HDL) cholesterol, triglyceride (TG), asparatate aminotransferase (AST), alanine aminotransferase (ALT), fasting plasma glucose. The genotype frequencies were observed at the frequencies of 24.3% for AA, 48.2% for AG and 27.5% for GG, respectively. When BMI and the biochemical parameters were compared by ANOVA among individuals with each genotype, the statistical difference was observed only for BMI (P=0.016). Bonferroni's test demonstrated that the men with the AG genotype have higher BMI than those with the AA genotype (22.4+/-2.8 vs. 21.4+/-2.2) (P=0.04). The individuals with the AG genotype also showed trend to have higher BMI than those with the GG, although the difference was not statistically apparent (22.4+/-2.8 vs. 21.5+/-2.3) (P=0.07). Our results indicated that the young healthy Japanese men with the AG heterozygote showed higher BMI than those with other genotypes.

A rapid and simple system of detecting deletions on the Y chromosome related with male infertility using multiplex PCR

Around 10% of males with idiopathic azoospermia or oligozoospermia, which are important causes of male infertility, have partial deletions on the long arm of the Y chromosome. To develop a rapid and accurate detection system for screening major Y deletions found in infertile men, we developed a multiplex PCR system that can simultaneously amplify five loci on the Y chromosome, SRY, AMELY, DBY, RBMY, DAZ and one locus on the X chromosome, AMELX. The size of the PCR products was designed to increase gradually from the distal Yp to the distal Yq. Our system could detect deletions of three major candidate regions for the azoospermic factor, AZFa, AZFb and AZFc on the Y chromosome together with sex. The gradual increase in the size of the PCR products was convenient for imaging the location of deletions on the Y chromosome. Moreover, the multiplex PCR system was combined with microchip-based electrophoresis, and the PCR products derived from each locus were separated within 4 min. Our system is useful for screening Y chromosomes bearing the structural anomalies including three major AZF deletions found among azoospermic or oligozoospermic males.

Ultrafast diagnosis of the genetic-related disorders using the combined technologies of multiplex PCR and multichannel microchip electrophoresis

For the diagnosis of unexplained male infertility a multiplex PCR for 6 markers, which are well-known as candidate genes for studying male infertility and located on the human Y-chromosome, has been designed. The multiplex PCR products have been separated on a 12 channel microchip electrophoresis system, which can analyze different samples simultaneously. By combining the technologies of multiplex PCR with multichannel microchip electrophoresis, the number of the DNA markers that can be screened simultaneously is increased to be 72 marker (12 x 6) in a single run while the electrophoresis analysis time is reduced to be only 180 s.

Survey of the two polymorphisms in DAZL, an autosomal candidate for the azoospermic factor, in Japanese infertile men and implications for male infertility

The DAZL (DAZ-like) gene is suggested to be an ancestral gene of the DAZ (deleted in azoospermia) gene on the Y chromosome, which is a strong candidate for the azoospermic factor. Recently, it has been reported that the T54A (Thr54-->Ala) polymorphism in exon 3 of the DAZL gene is associated with spermatogenic failure in the Taiwanese population. In this study, to investigate whether this polymorphism is associated with spermatogenic failure in Japanese males, we analysed genomic DNA derived from 234 patients with azoospermia or oligozoospermia and 131 fertile controls. The T54A polymorphism was completely absent in both the patients and the controls. The T12A (Thr12-->Ala) polymorphism in exon 2 of the DAZL gene was found at a similar frequency in the patients and controls, 15.4% and 13.7%, respectively (P = 0.67). However, the frequency of T12A was higher for the azoospermic (20.5%) than oligozoospermic (9.6%) individuals in infertile men without DAZ deletions, although statistical difference was not so apparent (chi2 test: P = 0.037, OR = 2.413, 95% CI = 1.035-5.629; Yate's chi2 test: P = 0.058, OR = 2.319, 95% CI = 0.973-6.166). Our results show that the T54A polymorphism in DAZL has no major role in Japanese males with azoospermia or oligozoospermia. The distribution of the T54A polymorphism may be restricted to the narrow area including Taiwan.

Multiplex PCR with multichannel microchip electrophoresis: an ultrafast analysis for genetic diseases

A Y chromosomal polymorphic markers screening strategy using a multiplex polymerase chain reaction (PCR) and DNA microchip electrophoresis technology has recently been developed. It is a part of the human Y chromosome haplotyping system for studying Japanese population genetics and its relationship with male spermatogenic failure. This strategy is based on optimizing and modifying the primer set concentrations while keeping all other components of the PCR mixtures and conditions similar to those of a singleplex PCR. Well-balanced PCR products are obtained without changing even the DNA oligomer melting temperatures. Here, a panel of primer sets are used to amplify two groups of Y chromosome markers. The first consists of five markers and the second consists of seven markers. Both are possibly deleted in infertile men. The microchip electrophoresis technology is fast and sensitive, enables direct molecular typing of several Y chromosomal markers, and is separated by a difference of as many as six base pairs.

Molecular analysis of TBL1Y, a Y-linked homologue of TBL1X related with X-linked late-onset sensorineural deafness

Recent progress in sequencing the human Y chromosome has unveiled a series of X-Y homologous genes. In the present study, we focused on Transducin beta-like 1Y (TBL1Y), which is a Y-linked homologue of TBL1X that is related with X-linked late-onset sensorineural deafness. Recently, it has been shown that TBLR1, another homologue whose gene resides on chromosome 3, and TBL1X act as a corepressor/coactivator exchanger for several nuclear receptors and transcription factors. However, the expression pattern and function of TBL1Y remain unknown. The RT-PCR analysis of the TBL1 family revealed that TBL1Y was expressed in all 13 tissues examined but not in leukocytes. Among the cell lines tested, however, it was only expressed in NT2/D1 cells and in lymphoblasts transformed with Epstein Barr (EB) virus. To compare the functions of the TBL1 family, we generated a series of expression plasmids for GAL4DBD-fused proteins of the TBL1 family. We carried out dual luciferase assays using these plasmids in combination with a plasmid having a luciferase reporter gene harboring 5xGAL4 binding sites. Unlike the other constructs, GAL4DBD-fused TBL1Y did not repress the promoter activity. Moreover, we found three novel polymorphisms in the TBL1Y gene, IVS7+9G>A, G268C, and IVS7+1G>C, which is presumed to cause splicing error. These polymorphisms are found in males within Y-haplogroup O3 (XO3e), which is defined as the Y-haplogroup O3 excluding O3e, a branch of O3. The results show that TBL1Y differs from other members of the TBL1 family in expression and function, suggesting other roles in maleness.

Molecular characterization of heat shock-like factor encoded on the human Y chromosome, and implications for male infertility

Azoospermia and oligospermia are major causes of male infertility. Some genes located on the Y chromosome are suggested as candidates. Recently, HSFY, which is similar to the HSF (heat shock transcription factor) family, has been mapped on the human Y chromosome as multicopies. However, newly available sequence data deposited at NCBI shows that only the HSFY gene located on Yq has a long open reading frame containing a HSF-type DNA-binding domain. HSFY is similar to LW-1 on the human X chromosome and a murine HSFY-like sequence (mHSFYL), 4933413G11Rik, on the mouse chromosome 1. LW-1 and mHSFYL have 53% and 70% homology to HSFY for amino acid sequences of their presumed DNA-binding domains, respectively. Comparison of the presumed DNA-binding domains unveiled that the three HSF-like factors, HSFY, LW-1, and mHSFYL, belong to a different class than conventional HSFs. When we screened for deletions on the Yq of males suffering from infertility, we found that HSFY was involved in interstitial deletions on the Y chromosomes for two azoospermic males who had DBY, USP9Y, and DAZ but did not have RBMY located on the AZFb. Expression analysis of HSFY, LW-1, and mHSFYL unveiled that they are expressed predominantly in testis. Furthermore, immunhistochemistry of HSFY in testis showed that its expression is restricted to both Sertoli cells and spermatogenic cells and that it exhibits a stage-dependent translocation from the cytoplasm to the nucleus in spermatogenetic cells during spermatogenesis. These results may suggest that deletion of HSFY is involved in azoospermia or oligospermia.

[Sex differentiation and sex chromosomes]

The mechanisms for sex differentiation and the genes on the sex chromosomes are varied among different species. For human, SRY is the only testis-determining factor on the Y chromosome and triggers the cascade for male sex-determination. However, even if normal SRY exists, the haploinsufficienty of SOX9 or KTS+ splicing form of WT-1 can cause male-to-female sex reversal. Furthermore, the duplication of the partial region on the X chromosome including DAX-1 gene can also cause male-to-female sex reversal. The sex-determining system seems to be sensitive for the gene dosage or the gene expression level.

Y-chromosomal DNA haplogroups and their implications for the dual origins of the Koreans

We have analyzed eight Y-chromosomal binary markers (YAP, RPS4Y(711), M9, M175, LINE1, SRY(+465), 47z, and M95) and three Y-STR markers (DYS390, DYS391, and DYS393) in 738 males from 11 ethnic groups in east Asia in order to study the male lineage history of Korea. Haplogroup DE-YAP was found at a high frequency only in Japan but was also present at low frequencies in northeast Asia, including 2.5% in Korea, suggesting a northern origin for these chromosomes. Haplogroup C-RPS4Y(711) was present in Korea and Manchuria at moderate frequencies: higher than in populations from southeast Asia, but lower than those in the northeast, which may imply a northern Asian expansion of these lineages, perhaps from Mongolia or Siberia. The major Y-chromosomal expansions in east Asia were those of haplogroup O-M175 (and its sublineages). This haplogroup is likely to have originated in southern east Asia and subsequently expanded to all of east Asia. The moderate frequency of one sublineage in the Koreans, haplogroup O-LINE1 (12.5%), could be a result of interaction with Chinese populations. The age of another sublineage, haplogroup O-SRY(+465), and Y-STR haplotype diversity provide evidence for relatively recent male migration, originally from China, through Korea into Japan. In conclusion, the distribution pattern of Y-chromosomal haplogroups reveals the complex origin of the Koreans, resulting from genetic contributions involving the northern Asian settlement and range expansions mostly from southern-to-northern China.

Roles of estrogen receptor alpha (ER alpha) in the regulation of the human Müllerian inhibitory substance (MIS) promoter

Sex differentiation consists of multi-step pathway that involves expression of many different genes. Müllerian duct inhibitory substance (MIS) has a key role for regression of the Müllerian duct during male sex differentiation. Recently, endocrine disruptors (EDs), which often have estrogen-like activities, have caused concern over worldwide. It has been reported that estrogen regulates the MIS expression. Therefore, we tested whether ER alpha and ER beta influence the MIS promoter activity in the NT2/D1 cell line which expresses many sex differentiation-related genes such as SRY, SOX9, and DAX-1. RT-PCR analysis revealed that the NT2/D1 cells express both ER alpha and ER beta in addition to MIS. Under the low concentration of 17beta-estradiol (E2), the over-expression of exogenous ER alpha increased the MIS promoter activity 3.3-fold compared with the control. However, as E2 concentration was increased, the MIS promoter activity was decreased. For ER beta, we could not observe alterations of the MIS promoter activity. Furthermore, the over-expression of the exogenous SF-1 inhibited the activation of the MIS promoter with ER alpha. Although it remains unclear whether the effects of ER alpha on the MIS promoter are mediated through the genomic or the no-genomic actions, the present results suggest that ER alpha up-regulates the MIS promoter activity in the NT2/D1 cells under low concentrations of E2, and that the two ERs may work in different manners for the MIS promoter activation. The present findings may be useful to understand the molecular mechanisms by which EDs or estrogens affect the MIS expression.

Evaluation of the effectiveness of laser in situ keratomileusis and photorefractive keratectomy for myopia: a meta-analysis

OBJECTIVE

To evaluate the effectiveness of laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) for correcting myopia.

METHODS

Study selection, data extraction, and quality assessment were performed by two of authors independently. Summary odds ratios and 95% confidence intervals were calculated by DerSimonian & Laird random-effects model and Mantel-Haenszel (fixed-effects) model. All calculations were based on an intention-to-treat and per protocol analysis.

RESULTS

Five hundred and eighty eyes (476 patients) from 5 randomized controlled trials were included in this study. At > or = 6 months follow-up, by random-effects model, the pooled odds ratios (OR, for LASIK vs. PRK) of postoperative uncorrected visual acuity (UCVA) of 20/20 or better for all trials were 1.31 (95% CI=0.77-2.22) by per protocol analysis and 1.18 (95% CI=0.74-1.88) by intention-to-treat analysis. In the refractive outcome, the pooled OR of the postoperative spherical equivalent refraction within +/-0.5 diopter (D) of emmetropia did not show any statistical significance, for which the OR were 0.75 (95% CI=0.48-1.18) by per protocol analysis and 0.70 (95% CI=0.47-1.04) by intention-to-treat analysis.

CONCLUSIONS

LASIK and PRK were found to be similarly effective for the correction of myopia from -1.5 to -15.0 D in a greater than 6 month follow-up.

Decolorization of indigo carmine by charcoal from extracted residue of coffee beans

The adsorption ability of charcoal from extracted residue of coffee beans for indigo carmine removal was investigated by the batch method. Differences in the removal ratio and removal rate of indigo carmine could be explained by differences in the properties of charcoal. In the relationship between the amount of indigo carmine adsorbed and the square root of elapsed time, a good linearity was recognized. Since the relationship between the amount of indigo carmine adsorbed and square root of elapsed time showed a good linearity, the intraparticle diffusion of indigo carmine onto pores of adsorbents was identified as the rate-limiting step in the adsorption process.

Range of separation of potential tool for bioseparation, microchip electrophoresis system, for DNA polymorphisms on the human Y-chromosome

For the requirement of a high, fast and sufficient technology to suit the needs of 21st century biotechnology, the separation range of a microchip electrophoresis system was studied. Two DNA fragments on the human Y-chromosome, SY594 (82 bp) and 12f2 (88 bp), were successfully separated with a reproducibility of 1.9% and an accuracy of 2.8%. Then, a mixture of 10 DNA markers ranging from 61 bp to 189 bp was successfully separated with high resolution. All of these results demonstrate the superiority of microchip electrophoresis as a tool for 21st century bioseparation.

Yfm1, a multicopy marker specific for the Y chromosome and beneficial for forensic, population, genetic, and spermatogenesis-related studies

A recently developed microsatellite marker on the Y chromosome, Yfm1, which was originally cloned from a cosmid clone mapped near the DAZ (Deleted in AZoospermia) genes, was used to classify Y chromosomes using an automatic sequencer. Yfm1 could detect multicopies on Y chromosomes in a single polymerase chain reaction, showing four main classes, A, A*, B, and C, according to the number of copies and peak patterns. Compound haplotype analysis of the Y chromosome using the Yfm1 marker with three other biallelic markers on the Y chromosome, SRY, DXYS5Y, and YAP, resulted in nine different haplotypes among different populations, including Japanese. Haplotype II (defined by YAP insertion) observed in the Japanese population was consistently associated with Yfm1 class A or A*, which showed the lowest number of copies of Yfm1. Haplotypes III and IV were consistently associated with Yfm1 class B. On the other hand, haplotype I showed a variety of Yfm1 patterns that were dubbed class C when not appropriately classified as A, A*, or B. These relationships among Yfm1 microsatellite and Y-specific biallelic markers could supply useful population genetic information. Moreover, because we have already shown that men with haplotype II have significantly lower spermatogenic ability than those with other haplotypes, Yfm1 class A or A* with the least number of copies may be related to the haplotype II-specific structure of the Y chromosome, such as deletion of DAZ or DAZ repeats, reflecting the lower spermatogenic abilities of Japanese haplotype II men. Thus, Yfm1 represents a very useful marker for analysis of genetic structure in different populations and studies on Y chromosome lineage-specific genotype-phenotype correlations.