Identification and Characterization of the Huanglongbing Bacterium in Pummelo from Multiple Locations in Guangdong, P. R. China

Huanglongbing (HLB, yellow shoot disease, ex. citrus greening disease), caused by Candidatus Liberibacter spp., is highly destructive to citrus production in Asia, Africa, and South America. Although primarily affecting sweet orange and mandarin, HLB has long been observed in pummelo in Guangdong Province, People's Republic of China; however, the disease in pummelo has received little research attention. Accordingly, it remains unclear how closely related the strains of Ca. Liberibacter in pummelo are to those in other citrus species. In this study, the loci of 16S rDNA, rplAJ (β-operon of ribosomal protein), and an outer membrane protein (omp) gene were analyzed and characterized among strains of Ca. Liberibacter in pummelo samples from six different locations in Guangdong. Sequence comparisons indicated that 'Candidatus Liberibacter asiaticus', but not 'Ca. Liberibacter africanus' or 'Ca. Liberibacter americanus', was exclusively associated with HLB symptoms in pummelo. The pummelo strains of 'Ca. Liberibacter asiaticus' from Guangdong were highly homogeneous. Analyses of single-nucleotide polymorphisms in the omp locus showed that the Guangdong pummelo strains grouped with 'Ca. Liberibacter asiaticus' strains from Thailand, Nepal, and an unspecified location in China but differed from the Philippine and China-Behai strains. Based on the sequence homogeneity at the omp locus, the history of pummelo culture and the means by which HLB is known to be spread, we believe that, likely, the pummelo strain of 'Ca. Liberibacter asiaticus' recently was spread to pummelo in the study areas from infected sweet orange or mandarin trees by insect vectors or by propagation of pummelo infected elsewhere.

A five-year follow-up study of goiter and thyroid nodules in three regions with different iodine intakes in China

OBJECTIVE

The association between iodine status and the prevalence of goiter and thyroid nodules has been well established but the extent to which different iodine intake levels influence the incidence of goiter and thyroid nodules is unclear. The aim of the study was to determine the incidence of goiter and thyroid nodules in 3 regions with different iodine intake levels: mildly deficient, more than adequate, and excessive.

DESIGN, PATIENTS AND MEASUREMENTS

Of the 3385 unselected subjects enrolled in 1999 in Panshan, Zhangwu, and Huanghua where median urinary iodine excretion (UIE) was 83.5 microg/l, 242.9 microg/l, and 650.9 microg/l, respectively, 2708 (80.0%) participated in the follow-up study in 2004. The examinations of thyroid ultrasonography, thyroid function, thyroid autoantibodies and UIE were performed at baseline and follow-up.

RESULTS

The cumulative incidence of diffuse goiter was 7.1%, 4.4%, and 6.9%, respectively, higher in Panshan and Huanghua than in Zhangwu (p=0.013 and p=0.015) and that of nodular goiter was 5.0%, 2.4%, and 0.8%, respectively, declining with increasing iodine intake levels (p<0.001). Mild iodine deficiency, chronic iodine excess as well as positive thyroid autoantibodies were associated with the occurrence of goiter [Logistic regression: odds ratio (OR)=1.83 (95% confidence interval (CI) 1.26-2.65), OR=1.46 (95% CI 1.01-2.11) and OR=1.68 (95% CI 1.14-2.48), respectively]. The cumulative incidence of single nodule was 4.0%, 5.7%, and 5.6%, respectively and that of multiple nodules was 0.4%, 1.2%, and 1.0%, respectively.

CONCLUSIONS

The relationship between iodine and the risk for the occurrence of diffuse goiter shows a U-shaped curve. Nodular goiters are more prevalent in iodine-deficient areas.

Effective management of main bronchial rupture in patients with chest trauma

BACKGROUND

The purpose of the current study was to investigate the most effective diagnostic method and the effect of surgical treatment on traumatic main bronchial rupture.

METHODS

Chest X-rays, CT and fiberoptic bronchoscopy were the main means used to confirm the diagnosis. Surgery was performed as early as possible.

RESULTS

Pneumonectomy was performed in 1 patient. Bronchial end-to-end anastomosis was performed in 10 patients whose lungs were well ventilated, and lung function recovered.

CONCLUSION

Main bronchial rupture occurs relatively rarely. Early diagnosis and operative intervention can save lives.

High iodine intake is a risk factor of post-partum thyroiditis: result of a survey from Shenyang, China

The aim of the present study is to obtain the epidemiological data on post-partum thyroiditis (PPT) firstly in Chinese women, and to tryto evaluate whether excessive intake of iodine in post-partum women imposes any danger of occurring PPT. Sixty hundred and ten pregnant women were involved in the cohort just before delivery. Four hundred and eighty-eight (80%) of them accepted taking part in follow-ups more than 6 months post-partum. A blood sample was taken from participants before delivery and every 3 months post-partum for testing of serum TSH, thyroid autoantibodies. Free T3 (FT3), free T4 (FT4) and TSH receptor antibody (TRAb) were detected if TSH was abnormal. The iodine nutrition was evaluated according to the mean level of the fasting urinary iodine excretions at different times during the studying period, and participants were subgrouped into 3 categories with low, adequate and high iodine intake. For those participants who had thyroid dysfunction within 6 months post-partum, the follow-up persisted for 1 yr. Of 488 pregnant women, PPT developed in 11.9% (58/488). Given overt and subclinical PPT, the prevalence was 7.17% (no.=35) and 4.71% (no.=23), respectively. There was a strong association between the presence of thyroid peroxidase antibody (TPOAb) at delivery and the risk of developing PPT [RR=6.76, 95% (CI) 4.42-10.34]. Overt cases had much higher titers of TPOAb than subclinical patients (all p<0.05). The median urinary iodine (MUI) of patients with PPT was significantly higher than that of healthy women (231.93 vs 199.88 microg/l p=0.00153). Both the prevalence of PPT and positive TPOAb rise with the increment of iodine intakes. Pregnant women with high iodine intake had more risk of developing PPT when compared with those with low iodine intake (RR=2.92, 95%CI 1.31-6.50). We concluded that positive TPOAb was of value for predicting the occurrence and severity of PPT, and a high iodine intake was a risk factor triggering PPT.

Increased fluid secretion after adenoviral-mediated transfer of the human aquaporin-1 cDNA to irradiated miniature pig parotid glands

The treatment of most head and neck cancer patients includes ionizing radiation (IR). Salivary glands in the IR field suffer irreversible damage. Previously, we reported that adenoviral (Ad)-mediated transfer of the human aquaporin-1 (hAQP1) cDNA to rat submandibular glands following IR restored salivary flow to near normal levels. It is unclear if this strategy is useful in larger animals. Herein, we evaluated AdhAQP1-mediated gene transfer after parotid gland IR (20 Gy) in the miniature pig. Sixteen weeks following IR, salivation from the targeted gland was decreased by >80%. AdhAQP1 administration resulted in a dose-dependent increase in parotid salivary flow to approximately 80% of pre-IR levels on day 3. A control Ad vector was without significant effect. The effective AdhAQP1 dose was 2.5 x 10(5) pfu/microl infusate, a dose that leads to comparable transgene expression in murine and minipig salivary glands. Three days after Ad vector administration little change was observed in clinical chemistry and hematology values. These findings demonstrate that localized delivery of AdhAQP1 to IR-damaged salivary glands increases salivary secretion, without significant general adverse events, in a large animal model.

Effects of prolactin on HLA-DR and CD40 expressions by human thyrocytes

OBJECTIVE

To study the effects of prolactin (PRL) on HLA-DR and CD40 expressions by human thyrocytes, and to investigate the possible mechanisms for PRL to affect the development of Graves' disease (GD).

METHODS

Thyrocytes in secondary culture, which were from GD thyroid glands and the tissues adjacent to the lesions of multinodular goiter and adenoma (control group), were treated respectively with ovine PRL (oPRL), interferon-gamma (IFN-gamma), interlukin-4 (IL-4) and oPRL plus IFN-gamma (10 U/ml) or IL-4 (5 ng/ml) for 7 days. HLA-DR and CD40 expressions on the thyrocytes were determined by immunofluorescent staining and flow cytometry.

RESULTS

oPRL (12.5 ng/ml-1000 ng/ml) had no significant direct effect on HLA-DR or CD40 expression. It did not significantly affect the stimulation of HLA-DR expressions on the two groups of thyrocyte treated with IFN-gamma or on GD thyrocytes treated with IL-4. oPRL could antagonize the stimulation of CD40 expressions by IFN-gamma and the inhibition by IL-4 on both groups of thyrocytes. The antagonizing effects were related to the concentrations of PRL. IFN-gamma-stimulated percentages of CD40+ thyrocytes and delta mean fluorescence intensity (dMF) in both thyrocyte sources were significantly reduced in the presence of 200 ng/ml oPRL (both GD and

CONTROL

P < 0.01 and P < 0.05, respectively;

CONTROL

P < 0.05) and 1000 ng/ml oPRL (GD: P < 0.01;

CONTROL

P < 0.05). oPRL caused significant increasing in IL-4-inhibited percentages of CD40+ cells from the two groups of thyrocytes at 12.5 ng/ml and 1000 ng/ml and dMF from GD thyrocytes at 1000 ng/ml (P < 0.05).

CONCLUSIONS

PRL can exert indirect effects on CD40 expressions on thyrocytes by antagonizing the modulatory actions of IFN-gamma and IL-4 with dose-related effects. This may be one important mechanism for PRL to affect the development of GD.

DNA amplification associated with double minutes originating from chromosome 19 in mouse hepatocellular carcinoma

DNA amplification is associated with genomic instability, the main characteristic of cancer cells, and it frequently involves protooncogenes. Double minute chromosomes (DM) and homogeneously stained regions (HSR) are cytological manifestations of DNA amplification. Gain of chromosome 19 is a recurrent alteration in mouse hepatocellular carcinoma (HCC). In one tumor cell line established from HCC developed in myc transgenic mice, DM derived from chromosome 19 were identified by spectral karyotyping and confirmed by fluorescence in situ hybridization (FISH). A probe generated by PCR from microdissected DM was localized by FISH on normal and HCC-derived cell lines on DM and chromosome 19 at two sites separated by several medium size G-bands. This organization of DM containing amplified sequences from separate loci of the same chromosome, indicates a complex mechanism of DNA amplification, possibly involving more than one gene. DM or HSR were not previously identified in mouse HCC and adult human HCC. The recognition of these loci could lead to the cloning of new genes or identification of known genes important in development or progression of HCC.

Genomic organization and expression of the doublesex-related gene cluster in vertebrates and detection of putative regulatory regions for DMRT1

Genes related to the Drosophila melanogaster doublesex and Caenorhabditis elegans mab-3 genes are conserved in human. They are identified by a DNA-binding homology motif, the DM domain, and constitute a gene family (DMRTs). Unlike the invertebrate genes, whose role in the sex-determination process is essentially understood, the function of the different vertebrate DMRT genes is not as clear. Evidence has accumulated for the involvement of DMRT1 in male sex determination and differentiation. DMRT2 (known as terra in zebrafish) seems to be a critical factor for somitogenesis. To contribute to a better understanding of the function of this important gene family, we have analyzed DMRT1, DMRT2, and DMRT3 from the genome model organism Fugu rubripes and the medakafish, a complementary model organism for genetics and functional studies. We found conservation of synteny of human chromosome 9 in F. rubripes and an identical gene cluster organization of the DMRTs in both fish. Although expression analysis and gene linkage mapping in medaka exclude a function for any of the three genes in the primary step of male sex determination, comparison of F. rubripes and human sequences uncovered three putative regulatory regions that might have a role in more downstream events of sex determination and human XY sex reversal.

Genomic organization and expression of the doublesex-related gene cluster in vertebrates and detection of putative regulatory regions for DMRT1

Genes related to the Drosophila melanogaster doublesex and Caenorhabditis elegans mab-3 genes are conserved in human. They are identified by a DNA-binding homology motif, the DM domain, and constitute a gene family (DMRTs). Unlike the invertebrate genes, whose role in the sex-determination process is essentially understood, the function of the different vertebrate DMRT genes is not as clear. Evidence has accumulated for the involvement of DMRT1 in male sex determination and differentiation. DMRT2 (known as terra in zebrafish) seems to be a critical factor for somitogenesis. To contribute to a better understanding of the function of this important gene family, we have analyzed DMRT1, DMRT2, and DMRT3 from the genome model organism Fugu rubripes and the medakafish, a complementary model organism for genetics and functional studies. We found conservation of synteny of human chromosome 9 in F. rubripes and an identical gene cluster organization of the DMRTs in both fish. Although expression analysis and gene linkage mapping in medaka exclude a function for any of the three genes in the primary step of male sex determination, comparison of F. rubripes and human sequences uncovered three putative regulatory regions that might have a role in more downstream events of sex determination and human XY sex reversal.

[Effect of iodine intake on thyroid diseases and intelligence among schoolchildren in rural areas]

OBJECTIVE

To understand the throid function and intelligence among the schoolchildren in three rural areas with different iodine intakes in China to probe the side-effect of excessive iodine intake on intelligence of schoolchildren.

METHODS

Chinese version of Raven's test was made among rural schoolchildren, 190 from Panshan County, Liaoning Province, a low iodine intake area with the median urinary iodine (MUI) of 99 microgram/L among its inhabitants, 236 from Zhangwu County, Liaoning Province, a moderate iodine intake area with the MUI of 338 microgram/L, and 313 from Huanghua County, Hebei Province, an excessive iodine intake area with the MUI of 631 microgram/L. Thyroid function, thyroid autoantibody (TAA), and MUI were determined among 116, 110 and 112 from the above-mentioned schoolchildren from these three areas respectively.

RESULTS

There was no significant difference among the prevalence rates of overt hyperthyroidism, subclinical hyperthyroidism and overt hypothyroidism in the areas of Panshan, Zhangwu and Huanghua. However, a significant difference was found among the prevalence rates of subclinical hypothyroidism in theses three areas (P = 0.001). The prevalence rates of subclinical hypothyroidism in Huanghua and Zhangwu were 4.76 and 3.37 times higher than that in Panshan (P = 0.001). TAA was negative among all of the schoolchildren with subclinical hypothyroidism except for one. No significant difference was found among the positive rates of thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TGAb) in these three areas. Serum thyroglobulin (TG) values in Huanghua were markedly higher than those in the other two areas (P = 0.015 7). Serum TG value in Zhangwu was higher than that in Panshan but with no significant difference. The IQ value of the schoolchildren in Huanghua was markedly higher than that in Zhangwu (P = 0.001 2). The IQ value of the schoolchildren in Panshan was lower than that in Huanghua and higher than that in Zhangwu but with no significant difference.

CONCLUSION

The increase of iodine intake may increase the risk of subclinical hypothyroidism among schoolchildren. In the area with excessive iodine intake, most of the subclicical hypothyroidism cases among schoolchildren are not of autoimmune origin. No obvious effect of excessive iodine intaue is found on mental development of schoolchildren.

One-step synthesis of a highly active, mesoporous, titanium-containing silica by using bifunctional templating

A highly active, three-dimensional, mesoporous titanosilica, TiTUD-1, with comparable properties to Ti-grafted mesoporous silica MCM-41, has been prepared in a one-step synthesis. A non-surfactant chemical, triethanolamine, was used as a template molecule. Triethanolamine easily forms complexes with titanium alkoxides, yielding titanatrane complexes, which together with free triethanolamine form meso-sized aggregates that template mesopores upon increasing the temperature of the synthesis mixture. Triethanolamine served as both mesopore template and ligand for the titanium complexes, which represent the majority of the catalytic-site precursors. The formation of the silica network and the titanium insertion were followed by a combination of diffuse reflectance UV/ Vis/NIR and FTIR spectroscopy. A titanium-rich phase was obtained on the mesopore surfaces during calcination, allowing for easy accessibility of the reactants to the catalytic sites. TiTUD-1 is about six times more active than framework-substituted Ti-MCM-41 and has similar activity to Ti-grafted MCM-41.

[A study of phenylketonuria heterozygotes screening in married population of Tianjin area]

OBJECTIVE

To find out a method that is simple and reliable for screening phenylketonuria(PKU) heterozygotes.

METHODS

Detecting and analyzing plasma phenylalanine(Phe) and tyrosine(Tyr) from 101 known-PKU heterozygotes and 2023 married people by means of a high performance liquid chromatograph.

RESULTS

Significant differences were observed between known- PKU heterozygotes and screening population in plasma Phe, Phe/Tyr and Phe(2)/Tyr. The values of plasma Phe, Phe/Tyr and Phe(2)/ Tyr from 94.1% known-PKU heterozygotes were higher than mean+2s of those values from screening population. According to the limits of mean+2s, 81 cases were screened out from the 2023 married people. It was the first time to get the actual heterozygote frequency of 4% from population.

CONCLUSION

The biochemical method mentioned above is available for use in screening PKU heterozygotes.

[Effects of prolactin on in-vitro interactions between thyrocytes from patients with Graves' disease and autologous peripheral blood mononuclear cells]

OBJECTIVE

To study the effects of prolactin on interactions between Graves' disease (GD) thyrocytes and autologous peripheral blood mononuclear cells (PBMC) in coculture.

METHODS

Primary thyrocytes and autologous PBMC were cocultured at various levels of ovine prolactin (oPRL) in vitro. The activation and proliferation of PBMC as well as HLA-DR and CD(40) expressions on thyrocytes were determined by immunofluorescent staining and flow cytometry.

RESULTS

With PBMC in GD cocultures, oPRL caused significant increase in the percentage of CD(4)(+) CD(25)(+) cells at 200 microg/L [(13.08 +/- 2.54)%, P < 0.01] and in the proliferative index at 200 microg/L [(17.82 +/- 3.02)%, P < 0.01] and 1,000 microg/L [(16.57 +/- 2.56)%, P < 0.05], but not at 12.5 microg/L [(10.43 +/- 2.38)% and (14.08 +/- 2.67)%, respectively] or 50 microg/L [(9.94 +/- 2.54)% and (14.56 +/- 2.80)%, respectively)]. The values at 200 or 1,000 microg/L as above were also significantly different from those at 12.5 or 50 microg/L. The percentage of CD(40)(+) cells [(48.25 +/- 6.63)%, (52.28 +/- 6.94)%] and delta mean fluorescence intensity (dMF; 42.94 +/- 10.24, 49.51 +/- 12.34) were significantly lower in thyrocytes in GD cocultures treated with 200 or 1,000 microg/L oPRL than those untreated [(58.38 +/- 6.62)% and 67.30 +/- 20.20] or treated with two other concentrations of oPRL. The percentage of HLA-DR + cells [(46.79 +/- 7.51)%, P < 0.01] and dMF (21.02 +/- 5.43, P < 0.01) were significantly higher in the thyrocytes treated with 50 microg/L oPRL than those untreated [(33.51 +/- 8.58)% and 13.91 +/- 3.88] or treated with three other concentrations. There were no significant differences between the dose groups of oPRL but those mentioned above.

CONCLUSIONS

Prolactin could affect interactions between GD PBMC and autologous thyrocytes and might eventually influence the shift of helper T cells. High prolactin levels might aggravate GD.

Effect of IFN-gamma, IL-4 on proliferation and synthesis of hyaluronic acid and collagen in cultured human retroorbital fibroblasts in vitro

OBJECTIVE

To investigate the cellular immune mechanism of thyroid associated ophthalmopathy (TAO) and provide a basis for treating TAO with cytokine or anti-cytokine agents, we determined whether interferon (IFN)-gamma and interleukin (IL)-4, representative cytokines of Th1 and Th2 cells, may have some effect on the development and progression of TAO.

METHOD

Retroorbital fibroblasts (RF) proliferation and the synthesis of hyaluronic acid (HA) and type IV collagen were measured with liquid scintillation and radioimmunoassay.

RESULTS

IFN-gamma stimulated RF proliferation and HA synthesis and had a significant inhibitory effect on type IV collagen synthesis. IL-4 stimulated proliferation and type IV collagen synthesis in RF and had inhibitory effect on HA synthesis. When IFN-gamma (100 U/ml) and IL-4 (1 microgram/L) were incubated together with RF, they antagonized their respective stimulatory or inhibitory effect on the proliferation and synthesis of HA and type IV collagen. Thyrotropin (TSH) stimulated RF proliferation and type IV collagen synthesis in a dose-dependent manner, while only at high dose (100 U/L and 200 U/L), stimulated RF to synthesize HA.

CONCLUSIONS

IFN-gamma, a representative cytokine of Th1 cells, is responsible for the inflammatory process of TAO; whereas IL-4, a representative cytokine of Th2 cells, has some effect on the repair process. IL-4 could antagonize the inflammatory effect of IFN-gamma on RF. TSH may have aggravating effect on the pathogenesis of TAO.

Sex-specific expression of an evolutionarily conserved male regulatory gene, DMRT1, in birds

Based on its Z-sex-chromosomal location and its structural homology to male sexual regulatory factors in humans (DMRT1 and DMRT2), Drosophila (Dsx), and Caenorhabditis elegans (Mab-3), chicken DMRT1 is an excellent candidate for a testis-determining factor in birds. The data we present provide further strong support for this hypothesis. By whole mount in situ hybridization chicken DMRT1 is expressed at higher levels in the male than in the female genital ridges during early stages of embryogenesis. Its expression becomes testis-specific after onset of sexual differentiation. Northern blot and RT PCR analysis showed that in adult birds DMRT1 is expressed exclusively in the testis. We propose that two gene dosages are required for testis formation in ZZ males, whereas expression from a single Z chromosome in ZW females leads to female sexual differentiation.

Conserved synteny between the chicken Z sex chromosome and human chromosome 9 includes the male regulatory gene DMRT1: a comparative (re)view on avian sex determination

Sex-determination mechanisms in birds and mammals evolved independently for more than 300 million years. Unlike mammals, sex determination in birds operates through a ZZ/ZW sex chromosome system, in which the female is the heterogametic sex. However, the molecular mechanism remains to be elucidated. Comparative gene mapping revealed that several genes on human chromosome 9 (HSA 9) have homologs on the chicken Z chromosome (GGA Z), indicating the common ancestry of large parts of GGA Z and HSA 9. Based on chromosome homology maps, we isolated a Z-linked chicken ortholog of DMRT1, which has been implicated in XY sex reversal in humans. Its location on the avian Z and within the sex-reversal region on HSA 9p suggests that DMRT1 represents an ancestral dosage-sensitive gene for vertebrate sex-determination. Z dosage may be crucial for male sexual differentiation/determination in birds.