Islet autoimmunity and genetic mutations in Chinese subjects initially thought to have Type 1B diabetes

AIMS

To explore the contribution of islet autoimmunity and genetic mutations in Chinese patients initially thought to have Type 1B diabetes.

METHODS

A group of 33 Chinese patients with newly diagnosed Type 1B diabetes, were identified by the absence of autoantibodies to glutamic acid decarboxylase (GAD), IA-2, insulin, thyroid globulin or thyroid peroxidase, or high-risk HLA-DQ haplotypes. The cohort was further characterized by measurement of autoantibodies to carboxypeptidase H (CPH) and SOX13 using radioligand assays, and testing for genetic mutations associated with MODY3/MODY6 and mitochondrial diabetes. Mutations of HNF-1alpha (MODY3) and neuroD1/beta2 (MODY6) genes were screened using the single-strand conformation polymorphism (SSCP) technique and sequencing. Mitochondrial DNA mutations were analysed with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

Within the cohort, we found one patient with a novel mutation, R321H (CGC-->CAC) in exon 5 of the HNF-1alpha gene, one with ND1 mt3316 G-->A mutation in mitochondrial DNA, five with Ala45Thr polymorphisms in the neuroD1/beta2 gene, and two patients with autoantibodies to SOX13.

CONCLUSIONS

Some of the Chinese patients originally thought to have Type 1B diabetes do have other evidence of islet autoimmunity and genetic mutations involved in the underlying aetiology. This suggests that more rigorous screening for these conditions is needed before classifying subjects as having Type 1B diabetes.

Kojic acid production in an airlift bioreactor using partially hydrolyzed raw corn starch

In a culture of Aspergillus oryzae MK-107-39 in a 3-l airlift bioreactor, kojic acid was not produced when glucose/wheat germ medium (GM1) was used. However, when a jar fermentor was used, the kojic acid yield was high. A suitable medium for culture in an airlift bioreactor consisting of partially hydrolyzed corn starch and a small amount of corn steep liquor (CSL) (SM1) was selected. In the cultivation in the airlift bioreactor using SM1, nearly 40 g/l of kojic acid was produced, which was the same as the amount produced in the jar fermentor containing GM1. The optimum aeration rate for the airlift bioreactor was 2.0 vvm (0.66 cm/s of superficial linear velocity (Vs)). The cost of SM1 using the airlift bioreactor was reduced to 40% that of GM1 using the jar fermentor. Furthermore, the energy cost of kojic acid production using SM1 in the airlift bioreactor was less than one-fourth of that for the jar fermentor using GM1.

Alcohol intake and hypertension subtypes in Chinese men

OBJECTIVE

To examine the associations between alcohol intake and isolated systolic hypertension (ISH), systolic-diastolic hypertension (SDH), and isolated diastolic hypertension (IDH).

DESIGN

Cross-sectional study of Chinese adults.

METHODS

We analyzed data from 5317 Chinese males who were not on antihypertensive medications from a nationally representative sample of Chinese adults aged 35-74 years. ISH was defined as a mean systolic blood pressure (SBP) >/=140 mmHg and a mean diastolic blood pressure (DBP) < 90 mmHg, SDH as a SBP >/= 140 mmHg and DBP >/= 90 mmHg, and IDH as SBP < 140 mmHg and DBP >/= 90 mmHg. Alcohol intake was determined using an interviewer-administered questionnaire and participants were categorized either as non-drinkers (<12 drinks in the prior year) or by tertile of alcohol intake.

RESULTS

The odds ratios of all three hypertension subtypes were higher at higher levels of alcohol intake, with those in the highest alcohol intake category (>/=30 drinks/week) 2.0 (95% confidence interval: 1.3, 3.0), 2.2 (1.6, 3.1), and 2.1 (1.4, 3.1) times more likely to have ISH, SDH, or IDH, respectively, than non-drinkers. The population attributable risk percentage due to heavy drinking (>/=30 drinks/week) was 13.9% for ISH, 13.4% for SDH, and 12.0% for IDH. Liquor drinking, specifically, was associated with a higher odds ratio of ISH, while SDH and IDH associations did not differ by type of alcoholic beverage.

CONCLUSIONS

In Chinese males, higher intake of alcohol is associated with higher risk of ISH, SDH, and IDH. Efforts to reduce hypertension in China should include a strong focus on decreasing heavy alcohol consumption.

Optimal Cutoff Point of Glutamate Decarboxylase Antibody Titers in Differentiating Two Subtypes of Adult-Onset Latent Autoimmune Diabetes

The optimal cutoff point of glutamate decarboxylase antibody (GAD-Ab) titers for differentiating two latent autoimmune diabetes (LADA) subtypes remains unclear. One hundred and forty-five GAD-Ab-positive patients screened from phenotypic type 2 diabetes were diagnosed as LADA. The clinical features were compared among LADA patients with different GAD-Ab titers. The receiver-operating characteristic (ROC) curve was used to evaluate the diagnostic value of GAD-Ab titers and to define the optimal cutoff point. The heterogeneity of clinical features in LADA could be discriminated by five GAD-Ab titers, with maximal differences at the titer of 175 U/mL. The ROC curve analysis showed that the optimal cutoff point for discriminating two LADA subtypes was at the titer of 175 U/mL, with sensitivity and specificity of 54.5% and 92.1%, respectively. These findings demonstrated that the two clinically distinct subtypes of LADA can be optimally discriminated by the GAD-Ab titers.

Hertz-Level Measurement of the Optical Clock Frequency in a Single 88Sr+ Ion

The frequency of the 5s 2S(1/2)-4d 2D(5/2) electric quadrupole clock transition in a single, trapped, laser-cooled 88Sr+ ion has been measured by using an optical frequency comb referenced to a cesium fountain primary frequency standard. The frequency of the transition is measured as 444,779,044,095,484.6 (1.5) hertz, with a fractional uncertainty within a factor of 3 of that of the cesium standard. Improvements required to obtain a cesium-limited frequency measurement are described and are expected to lead to a 88Sr+ optical clock with stability and reproducibility exceeding that of the primary cesium standard.

Measurement of the electric quadrupole moment of the 4d2D5/2 level in 88Sr+

The quadrupole moment of the 4d (2)D(5/2) level in 88Sr+ has been measured to be 2.6(3)ea(2)(0), where a(0) is the Bohr radius and e the elementary charge. A single laser-cooled strontium ion was confined in an end cap trap with a variable dc quadrupole potential, and measurements were made on the 5s (2)S(1/2)-4d (2)D(5/2) transition at 674 nm using a femtosecond optical frequency comb. This work shows that measurements of the unperturbed 88Sr+ transition frequency with sub-Hz uncertainty are possible and is important in understanding the reproducibility of ion trap optical frequency standards.

Recombinant matrix metalloproteinase-14 catalytic domain induces apoptosis in human osteoblastic SaOS-2 cells

Our study previously showed that estrogen and progesterone stimulated the production of matrix metalloproteinase-14 [MMP-14, or also named membrane type matrix metalloproteinses-1 (MT1-MMP)] in osteoblastic cells. MMP-14 was implied to regulate the function of osteoblasts by degrading bone matrix or growth factors, but the mechanism is unclear. Since MMP-14 plays a role primarily through the catalytic domain, and truncated MMP-14 containing the catalytic domain and lacking transmembrane domain can be secreted into medium by cultured cells, our present study was performed to observe the direct effects of recombinant MMP-14 catalytic domain on cultured human osteoblastic osteogenic sarcoma (SaOS)-2 cells. Our data showed that recombinant MMP-14 catalytic domain activated proMMP-2 secreted into media by SaOS-2 cells, and this process was blocked by ethylenediamine tetraacetic acid (EDTA) treatment. Recombinant MMP-14 catalytic domain inhibited the adhesion of SaOS-2 cells to immobilized type I collagen or fibronectin in a dose-dependent manner, and these effects on SaOS-2 cells were abolished by EDTA. Recombinant MMP-14 catalytic domain induced SaOS-2 cells apoptosis in a dose-dependent manner, and apoptosis-inducing activity of MMP-14 catalytic domain was blocked if it was treated with EDTA. In conclusion, we revealed that recombinant MMP-14 catalytic domain induced SaOS-2 cells apoptosis. We also indirectly showed the activity of MMP-14 catalytic domain to degrade extracellular matrix (ECM) in cultures of SaOS-2 cells through Gelatin Zymograms and adhesion assay. This suggests that since adhesion of cells to ECM serves as a survival mechanism in osteoblasts, the catalytic activity of recombinant MMP-14 catalytic domain on matrix proteins contributes to its apoptosis-inducing activity.

A comparison study of the reference curves of bone mineral density at different skeletal sites in native Chinese, Japanese, and American Caucasian women

To understand the differences among reference curves for bone mineral density (BMD) for Chinese, Japanese, and American Caucasian women, we measured the BMD at the anteroposterior (AP) lumbar spine (L1-L4), lateral lumbar spine (L2-L4), hip (including the femoral neck, trochanter, intertrochanter, Ward's triangle, and total hip), and ultradistal forearm by the dual-energy X-ray absorptiometry (DXA) in a total of 2728 healthy Chinese women, aged 5-96 years. Documented BMD data for Japanese women and device manufacturer's BMD new reference databases (including the NHANES III dataset) for American Caucasian women were also used in this study. The cubic regression model was found to fit best in analyzing the age-associated variations of BMD at various sites in Chinese women, i.e., the equations had the largest coefficient of determination (R2). At the AP/Lat spine, trochanter, intertrochanter, and Ward's triangle, BMD reference curves for Chinese women were lower than those for Japanese or Caucasian women, while at the femoral neck, total hip, and ultradistal forearm, the reference curves for Chinese women were higher than those for Japanese women, with overlaps and crossing of the curves for some age spans in comparing the Chinese and Caucasian women. There were significant differences in the peak BMD (PBMD) at various sites among the Chinese, Japanese, and Caucasian women (P = 0.000). The PBMDs for Chinese women at the lumbar spine and various sites of the hip were 5.7% +/- 2.1% (mean +/- SD, range, 2.7-7.9%) lower than those for Japanese women and 5.1% +/- 2.7% (range, 0.5-7.2%) lower than those for Caucasian women; however, the PBMDs for Chinese women were 26.2% higher than those for Japanese women and 10% higher than those for Caucasian women at the ultradistal forearm. After the PBMD, average T-scores of Chinese women for losses at the AP lumbar spine with increasing age were nearly identical to those for Japanese women, but both were greater than those for Caucasian women. The average T-scores for BMD loss at various sites in Chinese women were higher than those for both Japanese and Caucasian women except at the femoral neck, where the T-scores of Chinese women were exceeded by those of both Japanese and Caucasian women. Estimated from the T-score curve of BMD loss, the age of osteoporosis occurrence at the femoral neck in Chinese women was about 10 years later than that in Japanese or Caucasian women; at the AP spine, Chinese women were similar to Japanese women; at the other sites, the age for occurrence of osteoporosis in Chinese women was about 5-15 years earlier than that in either Japanese or Caucasian women. There are differences in prevalence or odds ratio (OR) of osteoporosis at the same skeletal region for Chinese, Japanese, and Caucasian women aged > or = 50 years or at different skeletal regions in women of the same race. The prevalences of osteoporosis at various regions of the hip in Chinese women are 10.1-19.8% and ORs are 22.0-32.3, of which prevalence at the femoral neck is the lowest (10.1%); the prevalences of osteoporosis in Japanese women are 11.6-16.8% and ORs are 21.1-26.3, of which prevalence at the femoral neck is the lowest (11.6%); and the prevalences of osteoporosis in Caucasian women are 13.0-20.0% and ORs are 19.4-48.9, of which prevalence at the femoral neck is the highest (20%). In conclusion, racial differences in BMD reference curves, prevalences, and risks of osteoporosis at various skeletal sites exist among native Chinese, Japanese, and American Caucasian women.

Variation near the region of the lipoprotein lipase gene and hypertension or blood pressure levels in Chinese

Essential hypertension (EH) is a common late-onset disease that exhibits complex genetic heterogeneity. Human lipoprotein lipase (LPL) is a rate-limiting enzyme that regulates the catabolism of triglycerides (TG) and chylomicrons (CM). Since dyslipidemia is a common finding in hypertensive patients, the LPL gene is a logical candidate gene that could contribute to the development of hypertension. Using linkage analysis in 148 Chinese hypertensive families, we identified a region of linkage with systolic blood pressure (SBP) and diastolic blood pressure (DBP) that consisted of a 10.6-cM interval defined by markers D8S1145, D8S261, and D8S282 on chromosome 8, which maps between 31 to 41.6 cM from the 8p-telomere contained LPL gene, with statistically significant p values for the marker D8S261 (p = 0.0021 for SBP, and p = 0.0395 for DBP). In the qualitative-trait linkage analysis, evidence for linkage between the marker D8S1145 and EH was found (p = 0.0286). The transmission/disequilibrium test (TDT/S-TDT) also supported a significant linkage-disequilibrium of the allele 3 of D8S261 with EH (chi2 = 8.643, p < 0.01). Furthermore, the marker neurofilament light polypeptide (NEFL) (11 cM centromeric to the LPL gene) appeared to be in linkage with SBP and DBP (p = 0.0329 for SBP; p = 0.0319 for DBP). Additionally, two flanking markers for LPL, D8S511 (9.5 cM telomeric to the LPL gene) and D8S560 (3.2 cM centromeric to the LPL gene), also showed significant linkage with EH (p = 0.0036 for D8S511; p = 0.0115 for D8S560). Previous knowledge about the physiological involvement of LPL in blood pressure regulation and the present findings of variation near the LPL gene support the proposition that a region near the LPL gene or the LPL gene itself might contribute to the individual blood pressure variation in Chinese.

[Observation on the infectivity of different densities of Plasmodium vivax to Anopheles sinensis]

AIM

To study the infectivity of different densities of P. vivax to An. sinensis.

METHODS

Venous blood samples from 38 volunteers artificially infected with P. vivax of South-Yunnan collected at the time of initial parasitaemia, primary attack and relapse, were used to infect Anopheles sinensis by feeding on parasitaemia blood in vitro. The finding of oocysts in the mid-gut of the mosquito by microscope was taken as criteria of positive infection.

RESULTS

P. vivax in the initial parasitaemia did not infect the mosquito. In the cases of primary attack, when the density of parasite was more than 100/microliter blood, the infectivity and intensity rose with the prolongation of the course of the disease and the increase in the density of the parasite. The infectivity of the P. vivax in the relapse cases was higher than in the primary attack cases, the mosquitoes could be infected at a parasite density of 1/microliter blood. The mosquitoes acquired a higher infection rate, a higher positive rate of mosquito mid-gut and a higher oocyst index in the primary attack cases whose parasite density were higher than 1,000/microliter blood and in the relapse cases whose parasite density were higher than 100/microliter blood.

CONCLUSION

The P. vivax in the period of clinical attack was one of the most dangerous period of the spread of malaria. The cases of relapse were the more dangerous infective sources in malaria transmission.

Two case reports of pituitary adenoma associated with Toxoplasma gondii infection

The involvement of the pituitary in cases of toxoplasmosis has been described in the literature only rarely. This is the first report to describe pituitary adenoma in association with Toxoplasma gondii infection. The two patients were 43 and 19 year old women. Radiological examination revealed tumours in the sellar region. Microscopically, the tumours consisted of small homogeneous polygonal or round cells. Toxoplasma cysts were found among the tumour cells, a finding confirmed by Toxoplasma gondii specific antibody immunohistochemistry. The association between pituitary adenoma and toxoplasma raises the possibility that T gondii might be involved in the development of certain cases of pituitary adenoma.

[Relationship between body mass index and major cardiovascular diseases in Chinese population]

OBJECTIVE

To study the relationship between body mass index (BMI) and major cardiovascular diseases (CVD) in Chinese population and explore an optimal range of BMI among adult Chinese in terms of prevention of CVD.

METHODS

Relevant data of 881 498 Chinese persons aged 18 and over in the Third National Sampling Survey on Hypertension held in 1991 were collected. The distribution of body weight and height and the relationship between BMI and prevalence of CVD were analyzed.

RESULTS

The average BMI was 21.7 kg/m(2) +/- 3.1 kg/m(2), 21.5 kg/m(2) +/- 2.9 kg/m(2),and 21.8 kg/m(2) +/- 3.3 kg/m(2) for the whole surveyed adults, the males and females respectively. The BMI was on the upward trend along with the age, reached the peak at the age 45 approximately 54, and then on a downward trend. The mean BMI was 22.4 kg/m(2) +/- 3.3 kg/m(2) for the northern population, 21.5 kg/m(2) +/- 3.0 kg/m(2) for the western population, and 21.1 kg/m(2) +/- 2.9 kg/m(2) for the southern population with a significantly difference between any two groups (all P < 0.01). The higher the mean BMI, the greater the prevalence of hypertension, myocardial infarction and stroke. The odds ratios for hypertension, myocardial infarction and stroke among those with the BMI >/= 25.0 approximately < 28 kg/m(2) were 2.8, 3.1, and 2.6 respectively, and were 4.8, 4.0, and 2.9 respectively among those with the BMI >/= 28 kg/m(2) (all P < 0.01) in comparison with the values among those with the BMI < 25.0 kg/m(2) after adjustment for age, and smoking and drinking habits using multivariate Logistic regression model. The odds ratio for clustering of >/= 2 kinds of diseases was 2.9 approximately 4.9 among those with the BMI >/= 25 approximately < 28 kg/m(2) and 3.4 approximately 8.9 among those with the BMI >/= 28 (P < 0.01 in comparison with that among those with the BMI < 25 kg/m(2)). The risks of myocardial infarction and hypertension by BMI were greater than the risk of stroke.

CONCLUSION

BMI less than 25 kg/m(2) is considered as an optimal range among Chinese adults. The BMI values of 25 kg/m(2) and 28 kg/m(2) can be recommended as thresholds of overweight and obesity for Chinese adults aged >/=18 respectively.

Congou tea drinking and oesophageal cancer in South China

The study from a large hospital-based case-control for 1248 cases with oesophageal cancer and the same number of controls in South China showed that Congou, a grade of Chinese black tea, may protect against cancers of the oesophagus and reduce the risk of a combination of alcohol drinking and smoking (especially smoking), regardless of temperature when drinking.

[Effects of health promotion for eight years on knowledge, attitude and behavior of cardiovascular diseases in rural Fangshan District, Beijing]

OBJECTIVE

To evaluate the effects of health promotion for eight years on cardiovascular diseases based on the changes in knowledge (K), attitude (A) and behavior (B) (KAB) before and after intervention in rural population of Fangshan, Beijing.

METHODS

Five townships in Fangshan District, Beijing were divided into intervention and control communities with cluster sampling. Totally 772 farmers were selected randomly for interviews with a questionnaire of KAB, including 424 in the intervention communities (IC) and 348 in the control communities (CC) in 1992. After community-based health promotion and education on cardiovascular prevention for eight years, 895 farmers, including 431 in IC and 464 in CC, were selected randomly again in 1999 to be interviewed with the same questionnaire of KAB used in 1992.

RESULTS

From 1992 to 1999, knowledge of cardiovascular diseases was significantly improved in residents of IC (P < 0.01) and CC. Compared to the residents in CC, there was a net increase in knowledge in residents of IC. Significant improvement was found in 10 and 11 of the 18 items of knowledge in males and females (P < 0.01), respectively. Level of knowledge in cardiovascular diseases was significantly higher in the residents of IC than those of CC in 1999. Proportions of those with positive attitudes and appropriate behaviors were significantly elevated in the residents of IC (P < 0.01), as well as prevalence of smoking and alcohol drinking decreased. However, as compared to CC, attitude and behavior in most aspects in the residents of IC changed positively, but in few aspects changed negatively. It suggested knowledge improved better than attitude and behavior changed.

CONCLUSIONS

Community-based health promotion and education for a longer term had obvious effects on improvement of knowledge in cardiovascular disease for rural population, but slower effects on changes in attitude and behavior, which suggested there still existed certain barriers to transform knowledge into healthy behavior.

A novel Notch ligand, Dll4, induces T-cell leukemia/lymphoma when overexpressed in mice by retroviral-mediated gene transfer

Notch receptors mediate cell-fate decisions through interaction with specific ligands during development. The biological role of a novel Notch ligand, Dll4, in mice was explored by reconstituting lethally irradiated mice with bone marrow (BM) cells transduced with Dll4 retroviral vector. White blood cell and lymphocyte counts in Dll4-overexpressing mice were reduced at the early stage of reconstitution but increased significantly at approximately 10 weeks after BM transplantation. BM, spleen, lymph nodes, and peripheral blood of Dll4-overexpressing mice contained predominantly CD4(+)CD8(+) T cells and virtually lacked B cells. The Dll4-overexpressing mice eventually developed a lethal phenotype that was characterized by the progression of a T-cell lymphoproliferative disease (restricted to BM and lymphoid tissues) to transplantable monoclonal T-cell leukemia/lymphoma scattered to multiple organs. Results suggest that the interaction of Dll4 with Notch1 may provide key signals for T-cell development.

[Construction of a subtracted cDNA library of differentially expressed genes in human normal liver tissue and primary hepatocellular carcinoma tissue]

OBJECTIVE

To construct a subtracted cDNA library of differentially expressed genes in human normal liver tissue and primary hepatocellular carcinoma (HCC) tissue.

METHODS

Using the suppression subtractive hybridization (SSH), a novel technique has been described recently. cDNA fragments of missing or low expressing tumor suppressor genes in HCC tissue were isolated using paracancerous normal liver tissue and HCC tissue as targets. Then these cDNA fragments were directly inserted into T/A cloning vector to set up the subtractive library. Amplification of the library was carried out with transformation of E.coli by high voltage electroperforation. One hundred positive bacteria clones were randomly picked and identified using enzyme restriction method.

RESULTS

The amplified library contained more than 4,000 positive bacteria clones. Random analysis of 100 clones with enzyme restriction method showed that all clones contained 200-600 bp inserts.

CONCLUSIONS

A subtracted cDNA library of differentially expressed genes in human normal liver tissue and HCC tissue is constructed successfully with SSH and T/A cloning techniques. The library is efficient and lays solid foundation for screening and cloning new and specific missing or low expressing tumor suppressor genes of HCC.