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.

Supplementation With Goldenseal (Hydrastis canadensis), but not Kava Kava (Piper methysticum), Inhibits Human CYP3A Activity In Vivo

The effects of goldenseal (Hydrastis canadensis) and kava kava (Piper methysticum) supplementation on human CYP3A activity were evaluated using midazolam (MDZ) as a phenotypic probe. Sixteen healthy volunteers were randomly assigned to receive either goldenseal or kava kava for 14 days. Each supplementation phase was followed by a 30-day washout period. MDZ (8 mg, per os) was administered before and after each phase, and pharmacokinetic parameters were determined using standard non-compartmental methods. Comparisons of pre- and post-supplementation MDZ pharmacokinetic parameters revealed significant inhibition of CYP3A by goldenseal (AUC(0-infinity), 107.9+/-43.3 vs 175.3+/-74.8 ng x h/ml; Cl/F/kg, 1.26+/-0.59 vs 0.81+/-0.45 l/h/kg; T(1/2), 2.01+/-0.42 vs 3.15+/-1.12 h; Cmax, 50.6+/-26.9 vs 71.2+/-50.5 ng/ml). MDZ disposition was not affected by kava kava supplementation. These findings suggest that significant herb-drug interactions may result from the concomitant ingestion of goldenseal and CYP3A substrates.

Pituitary tumor transforming gene interacts with Sp1 to modulate G1/S cell phase transition

Pituitary tumor transforming gene (PTTG1) was isolated from rat pituitary tumor cells, and subsequently identified as a securin protein as well as a transcription factor. We show here a global transcriptional effect of PTTG1 in human choriocarcinoma JEG-3 cells by simultaneously assessing 20,000 gene promoters using chromatin immunoprecipitation (ChIP)-on-Chip experiments. Seven hundred and forty-six gene promoters (P<0.001) were found enriched, with functions relating to cell cycle, metabolic control and signal transduction. Significant interaction between PTTG1 and Sp1 (P<0.000001) was found by transcriptional pattern analysis of ChIP data and further confirmed by immunoprecipitation and pull-down assays. PTTG1 acts coordinately with Sp1 to induce cyclin D3 expression approximately threefold, and promotes G1/S-phase transition independently of p21. PTTG1 deletion was also protective for anchorage-independent cell colony formation. The results show that PTTG1 exhibits properties of a global transcription factor, and specifically modulates the G1/S-phase transition by interacting with Sp1. This novel signaling pathway may be required for PTTG1 transforming activity.

Homoharringtonine in combination with cytarabine and aclarubicin resulted in high complete remission rate after the first induction therapy in patients with de novo acute myeloid leukemia

To assess the efficacy and toxicity of HAA regimen (homoharritonine 4 mg/m2/day, days 1-3; cytarabine 150 mg/m2/day, days 1-7; aclarubicin 12 mg/m2/day, days 1-7) as an induction therapy in the treatment of de novo acute myeloid leukemia (AML), 48 patients with newly diagnosed AML, aged 35 (14-57) years, were entered into this clinical study. The median follow-up was 26 months. Eighty-three percent of patients achieved complete remission (CR), and the first single course of induction HAA regimen resulted in CR rate of 79%. The CR rate of 100, 82 and 33% were achieved in patients with favorable, intermediate and unfavorable cytogenetics, respectively. For all patients who achieved CR, the median time from the initiation of the induction therapy to the evaluation of the remission status was 32 days. For all patients, the estimated 3 years overall survival (OS) rate was 53%, whereas for patients with M5, the estimated OS rate at 3 years was 75%. The toxicities associated with HAA regimen were acceptable, and the most common toxicity was infection. This study suggested that HAA regimen might be a well-tolerable, effective induction regimen in young adult patients with AML.

Oxidative stress potentiates BACE1 gene expression and Abeta generation

Alzheimer's Disease (AD) is the most common neurodegenerative disorder leading to dementia and its prevalence increases with age. The pathological features of AD are characterized by the beta-amyloid protein (A(beta)) deposits in the core of neuritic plaques and abnormal neurofibrillary tangles in the brain of AD patients. BACE1 is the major beta-secretase to cleave the beta-amyloid precursor protein (APP) to generate A(beta). Oxidative stress has been shown to affect A(beta) generation in the AD pathogenesis and the mechanism of such effect is unknown. In this report we generated a novel promoterless enhanced green fluorescent protein (EGFP) reporter gene cloning vector and cloned a 1.9-kb BACE1 gene promoter fragment in this vector. The BACE1 promoter fragment can efficiently activate EGFP or luciferase gene transcription. Oxidative stress induced by hydrogen peroxide resulted in significant increase in the BACE1 promoter activity. Furthermore, hydrogen peroxide treatment facilitated beta-secretase activity and A(beta) generation. Thus, upregulation of BACE1 transcription by oxidative stress may contribute to the pathogenesis of Alzheimer's disease.

Chitosan-coated liposomes: characterization and interaction with leuprolide

The objective of the present work was to investigate the effect of chitosan concentration and lipid type on the characteristics of chitosan-coated liposomes and their interactions with leuprolide. Liposomes from lipid of high purity and low purity were prepared and coated by chitosan. Physical properties, drug entrapment efficiency, and stability upon dilution were respectively compared. Results showed that the particle size increment of liposomes from low purity lipid was larger than that from high purity lipid, indicating a thicker coating layer. The high zeta potential of particles from low purity lipid was thought to play an important role in the resistance to flocculation. As to particles from high purity lipid, polymer bridging caused flocculation at low polymer concentration while at high concentration, the adsorbed chitosan molecule led to steric stabilization. Drug entrapment efficiency decreased as chitosan was added to liposomes, showing the disturbance of bilayers. Upon dilution, the leakage of leuprolide from low purity liposomes was larger than that from high purity liposomes. In conclusion, low purity lipid possessed more negative charge and formed thicker adsorptive layer by stronger electrostatic attraction with chitosan. The interaction between chitosan and the polar head groups on the surface of phospholipid bilayers may interfere with leuprolide entrapped in liposomes and result in the leakage of leuprolide.

Outcome of endovascular intervention for infrainguinal vein graft stenosis

Assisted graft patency rate following revision of a graft stenosis is far better than that following thrombectomy of an occluded graft. Graft revision by endovascular means has been proposed as a suitable alternative to more invasive surgery. This study reports our experience with endovascular treatment of vein graft stenosis. Between December 1992 and September 2000, percutaneous transluminal balloon angioplasty (PTA) was performed on 90 vein graft stenoses in 87 infrainguinal vein bypass grafts identified by routine graft duplex scan (peak systolic velocity, PSV > 300 cm/sec). All 90 stenoses treated by PTA were retrospectively analysed for stenosis-free patency rate (life-table analysis). Re-stenosis was defined by PSV exceeding 300 cm/sec at the same site of the vein graft where a stenosis was dilated. Ninety vein graft stenoses (72 primary stenoses and 18 recurrent stenoses) in 33 femoropopliteal (above knee), 30 femoropopliteal (below knee) and 24 femorotibial vein bypass grafts were treated by PTA. The timing of PTA ranged from one to 252 months (mean, 23.9 months) from the initial surgery. Cumulative stenosis-free patency rate after PTA was 55.8% at 6 months, 54.0% at one year and 45.0% at three years. Stenosis-free patency rate at six months was significantly lower for revision of recurrent stenosis (25.9%) than for primary stenosis (61.6%) (P = 0.01). The revision of duplex scan detected vein graft stenosis with endovascular intervention was associated with an acceptable stenosis-free patency rate. However, recurrent stenosis treated by PTA had a significantly inferior outcome. Direct surgical revision would be more appropriate for recurrent lesions.

The pro-apoptotic protein, Bik, exhibits potent antitumor activity that is dependent on its BH3 domain

The Bcl-2 homology 3 (BH3) domain is present in most members of the Bcl-2 protein family and is required to confer the death-inducing properties of pro-apoptotic members, including Bax, Bak, Bad, and Bik, in cell-based assay systems. To determine whether the BH3 domain possesses a similar role in tumor tissues in vivo, we overexpressed the wild-type Bik protein and its BH3-deleted counterpart, using adenoviral technology, in chemoresistant human tumor prostate (PC-3) and colon (HT-29) cell lines growing in vitro and in vivo. Bik caused apoptosis in both PC-3 and HT-29 cells in vitro by inducing the release of cytochrome c from mitochondria to cytoplasm, resulting in the catalytic activation of caspases 9, 7, and 3 and cleavage of poly(ADP-ribose) polymerase and DNA fragmentation. When the BH3 domain was deleted from the Bik protein, no effect on mitochondrial activity or cell morphology could be observed. Furthermore, intratumoral injection of an adenovirus vector expressing the Bik gene, but not the deleted BH3 Bik gene, suppressed the growth of PC-3 and HT-29 xenografts established in nude mice. Histological examination of tumors from mice treated with the wild-type Bik adenoviral construct demonstrated cellular debris, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling positive staining, and morphological changes associated with apoptosis. In contrast, tissue sections obtained from tumors treated with the BH3-deleted Bik adenoviral construct showed no evidence of apoptosis. Thus, our results suggest that the BH3 domain is required for the antitumor activity of the Bik protein and provides a novel therapeutic approach for cancer therapy.

The structure of a Michaelis serpin-protease complex

Serine protease inhibitors (serpins) regulate the activities of circulating proteases. Serpins inhibit proteases by acylating the serine hydroxyl at their active sites. Before deacylation and complete proteolysis of the serpin can occur, massive conformational changes are triggered in the serpin while maintaining the covalent linkage between the protease and serpin. Here we report the structure of a serpin-trypsin Michaelis complex, which we visualized by using the S195A trypsin mutant to prevent covalent complex formation. This encounter complex reveals a more extensive interaction surface than that present in small inhibitor-protease complexes and is a template for modeling other serpin-protease pairs. Mutations of several serpin residues at the interface reduced the inhibitory activity of the serpin. The serine residue C-terminal to the scissile peptide bond is found in a closer than usual interaction with His 57 at the active site of trypsin.

[Experimental study on carcinogenic activity of the organic extracts from water of the sifangtai section of songhua river]

OBJECTIVES

To study the carcinogenic activity and potential mechanism of the organic extracts from the Songhua River in vitro.

METHODS

The in vitro cell transformation and single cell gel electrophoresis (SCGE) tests were detected with the ether extracts of water. The expression of anticancer genes p53, p16, and p21 measured by immunohistochemical assays and the apoptosis by TUNEL assay were also studied.

RESULTS

The extracts from the water induced malignant transformation of BALB/C mouse embryo fibroblast cells and induce DNA damage. p53, p16 and p21 failed to express in transformed cells induced by the water extracts, and the apoptosis rate of transformed cells decreased.

CONCLUSION

This study demonstrates that the organic extracts from the Songhua River has potential carcinogenicity.

Combined intratumoral injection of bone marrow-derived dendritic cells and systemic chemotherapy to treat pre-existing murine tumors

Dendritic cells (DCs) are attractive candidates for innovative cancer immunotherapy by virtue of their potential to function as professional antigen-presenting cells for initiating cellular immune responses. In this study, we evaluated a possible synergy of conventional chemotherapy together with intratumoral injection of syngeneic bone marrow-derived DCs for the treatment of preexisting tumors. Using murine CT26 colon adenocarcinoma cells (parental or modified to express beta-galactosidase as a model tumor antigen) to produce s.c. tumors in syngeneic BALB/c mice, the data demonstrate that direct injections of DCs at the tumor site result in partial eradication of established tumors. Strikingly, the addition of systemic chemotherapy (cyclophosphamide) combined with local intratumoral injection of DCs led to complete tumor regression in the treated animals. The tumor-free mice were able to resist a repeat challenge with the same tumor, suggesting that the animals had acquired long term antitumor immunity. Supporting evidence for the paradigm of systemic chemotherapy and intratumoral administration of DCs was obtained using melanoma B16 syngeneic tumor treated with Adriamycin plus DCs. These novel findings raise the possibility of using this potent strategy of combined intratumoral injections of DCs and systemic chemotherapy for cancer treatment.

Reversing drug resistance in the ovarian carcinoma cell line SKOV3/mdr1 in vitro by antisense oligodeoxynucleotides

OBJECTIVE

To investigate the effect of multidrug resistance gene 1 (mdr1) antisense oligodeoxynucleotides (ODNs) on reversing multidrug resistance in the drug resistant ovarian carcinoma cell line SKOV3/mdr1.

METHODS

The ovarian carcinoma cell line SKOV3 transducted with a human multidrug resistance gene (mdr1) served as the drug resistant model (SKOV3/mdr1). The mdr1 antisense ODNs was transfected into SKOV3/mdr1 cells while mediated by lipofectamine. Reverse transcription-polymerase chain reaction (RT-PCR) was used to measure the expression and the amount of the mdr1 mRNA in the cells. The positive rate and function of the mdr1 gene product P-glycoprotein (Pgp) in the mdr1 antisense ODNs treated SKOV3/mdr1 cells were determined by flow cytometry and rhodamine 123 efflux. Drug resistance in the SKOV3/mdr1 cell line was observed by MTT assay and cell colony culture.

RESULTS

The mdr1 mRNA level was decreased to about 60% of that of beta-actin after mdr1 antisense ODNs treatment. The Pgp positive rate of mdr1 antisense ODNs treated SKOV3/mdr1 cells decreased from 100% to 52.6% (P < 0.01). The intracellular rhodamine 123 retention was increased from 9.1% to 33.8% (P < 0.01). The chemoresistance to taxol decreased to 58% of SKOV3/mdr1 with mdr1 antisense ODN treatment. Compared with SKOV3/mdr1 cells in the control group, under a certain range of drug concentrations, the number of drug resistance colonies in mdr1 antisense ODNs treated SKOV3/mdr1 cells for taxol and doxorubicin decreased by 8.6 +/- 0.8 fold and 3.1 +/- 0.6 fold, respectively. Some non-specific functions during oligodeoxyncleotide treatment was also detected.

CONCLUSION

mdr1 expression in the SKOV1/mdr1 cell line was partially inhibited after mdr1 antisense ODNs treatment at the mRNA and protein level, increasing the chemotherapy sensitivity of this drug resistant ovarian carcinoma cell line.

[Effect of Xue Zhi Kang on the formation of fatty liver in cholesterol-fed rabbits]

OBJECTIVE

To explore the effect of Xue Zhi Kang (XZhK) on the formation of fatty liver in cholesterol-fed rabbits.

METHODS

XZhK was refined from Chinese traditional medicine Hong Qu and its main composition is HMG-CoA reductase inhibitor. Thirty New Zealand white rabbits were randomly assigned into 3 groups (control, hypercholesterol-fed, and XZhK groups) during the 12 week's experiment. The effects of XZhK (0.8g.kg(-1).d(-1)) were investigated in rabbits fed a l.5% cholesterol diet. The changes of serum TC, TG, HDL-C, and LDL-C concentrations and the histopathological changes of the liver were detected.

RESULTS

The serum TC, LDL-C, and TG levels decreased in XZhK group compared with those in the cholesterol-fed control group (P<0.05 ). The serum HDL-C concentration slightly increased, but there was no statistical significance. The fatty degeneration of liver was ameliorated in XZhK group (P<0.05).

CONCLUSIONS

XZhK can modulate the lipid metabolism and inhibit the formation of fatty liver in cholesterol-fed rabbits.

[FTIR study on the normal and cancerous stomach tissues]

Tissues of cancerous and corresponding normal stomach were studied by FTIR technique. The results showed that there are obvious differences between FTIR spectra of them in spectral parameters such as frequency, intensity and band shape etc. The changes involving the phosphate symmetric stretching nu s, PO2- and asymmetric stretching nu as, PO2- modes, the CH3 and CH2 groups stretching (nu s, CH2, nu as, CH3) and bending (delta CH2) modes and the C-O stretching nu C-O mode were discussed. In addition, the changes of structure of hydrogen-bonding of nucleic acid and cell proteins and the packing and the conformational structure of the membrance lipids were analysed further. The average wavenumber of band of nu s, PO2- shifted from 1,080.92 cm-1 to 1,085.93 cm-1 and that of nu as, PO2- shifted from 1,239.64 cm-1 to 1,238.73 cm-1 which indicated that the degree of hydrogen-bonding formed by oxygen atom of the phosphodiester groups of nucleic acids was increased. The average wavenumber of band of delta CH2 of membrance lipids shifted from 1,455.23 cm-1 to 1,457.37 cm-1 that suggested that the conformational structure of the methylene chains of membrance lipids is more disordered than in normal tissues. The shift of band of nu C-O of cell proteins from 1,166.08 cm-1 to 1,166.58 cm-1 indicated that the hydrogen-bond of cell proteins become weaker.

[Study on interactions between TPO molecules tested with yeast two-hybrid system]

OBJECTIVE

To explore the interactions between TPO molecules and their locations.

METHODS

Full-length TPO, TPO(N) and TPO(C) were inserted respectively into the plasmids of the yeast two-hybrid system. Six different recombinant plasmids were generated. Every 2 recombinant plasmids were transformed into the yeast cell SFY526. The possible interactions between TPOs were then tested by the bioactivity of beta-galactosidase.

RESULTS

There are interactions between full-length TPO themselves TPO(N) themselves and TPO with TPO(N), but not between TPO(C)themselves, TPO with TPO(C) and TPO(N) with TPO(C).

CONCLUSION

Naturally, the molecular interaction domain of TPO may exist in the N terminus but not in the C terminus.

Mössbauer study of atmospheric aerosols of Shanghai

Three iron-containing atmospheric aerosol samples were collected, one at a tunnel, one near a viaduct, and one at a park in Shanghai City. These samples were studied by Mössbauer spectroscopy. The experimental results show that ultrafine particles alpha-Fe2O3 (about 13 nm) are the main component of the iron-containing atmospheric aerosols in the tunnel, and high-spin Fe3+ in sulfate containing a small amount of alpha-FeOOH is the main component of iron-containing particles in the aerosols from the other two places. The concentrations of iron in these locations, compared with those of some foreign cities, are much higher. To explore the chemical compositions of iron compounds in aerosols, SPM (scanning proton microprobe) has also been used. From these results, a possible chemical process by which the iron oxides converted to iron sulfate in air was discussed.

Determination of diphenylamine stabilizer and its nitrated derivatives in smokeless gunpowder using a tandem MS method

A novel method for determination of diphenylamine (DPA) and its nitrated derivatives, which are considered as characteristic components in smokeless powder and gunshot residues, is described. A tandem mass spectrometric method is established and mass spectrometer parameters optimized for each compound to obtain higher sensitivity. Under optimum conditions, quantitative analysis was carried out. The linear ranges are 5.0-200.0, 2.0-200.0 and 5.0-250.0 ng ml-1 and the detection limits are 1.0, 0.5 and 2.5 ng ml-1 for diphenylamine (DPA), N-NO-diphenylamine (N-NO-DPA) and 4-NO2-diphenylamine (4-NO2-DPA), respectively. Intra-assay and inter-assay precision and accuracy of analysis of these three samples were investigated. Based on the regression lines obtained above, smokeless samples were analyzed. It was found that there are 0.952% DPA, 0.384% N-NO-DPA and 0.128% 4-NO2-DPA in smokeless powder. Recovery tests showed that using cotton swabs, 80.3 +/- 4.9% DPA, 79.6 +/- 3.1% N-NO-DPA and 83.1 +/- 5.4% 4-NO2-DPA could be recovered from human hands.

Absence of mutations in the coding regions of follicle-stimulating hormone receptor gene in Singapore Chinese women with premature ovarian failure and polycystic ovary syndrome

Normal gonadal function is critically dependent on the integrity of pituitary-gonadal axis, where follicle-stimulating hormone (FSH) plays a key role. In the female, FSH is required for follicular growth, estrogen production and oocyte maturation. Its function is mediated by its specific receptor (FSHR), and defective FSHR has been shown to affect folliculogenesis and ovarian function. In this study, we screened the entire coding region of FSHR gene for pathogenic mutations in women with premature ovarian failure (POF) (n = 16) and polycystic ovary syndrome (PCOS) (n = 124) and found no mutations in these patients. Two known polymorphisms, Thr307Ala and Ser680Asn showed similar distributions of the allelic variations and protein isoforms in PCOS and normal control subjects (n = 236). It appears from this study that mutations in the coding regions of FSHR gene are not a causative factor of the above clinical manifestations in Chinese Singapore women.

[Expression of human anti-HBsAg-interferon fusion protein in CHO cells]

OBJECTIVE

To study the possibility of expressing human anti-HBsAg-interferon fusion protein in CHO cells as a putative targeting drug for hepatitis B.

METHODS

Both the heavy and light chain genes of human anti-HBsAg antibody derived from a phage display library were fused with alpha-2b interferon (IFN-alpha-2b) gene in vitro by polymerase chain reaction. The IFN alpha-2b gene was placed at the C terminal and a 15 amino acid linker was introduced at the fusion site. The light chain-IFN expression plasmid pLIC was constructed with a mammalian expression vector pcDNA3.1(+) and the heavy chain-IFN expression plasmid pFID was constructed with another mammalian expression vector pCdhfr1. These plasmids and the anti-HBsAg full-length light and heavy chain expression plasmids (pLIC and pHFD, respectively) were transfected into CHO (dhfr-) cells by the following three combinations:I, pLIC + pHFD;II, pLIC + pFID; III, pLFC + pFID. The cultured supernatant of the transfected cells was collected and assayed for IFN activity and HBsAg affinity.

RESULTS

The supernatant of combination I and II displayed IFN activity but only combination I supernatant exhibited HBsAg affinity.

CONCLUSIONS

The successful expression of a fusion protein with both HBsAg affinity and interferon activity may lead to a new way to make a targeting drug for hepatitis B.

Analysis of lipooligosaccharide biosynthesis in the Neisseriaceae

Neisserial lipooligosaccharide (LOS) contains three oligosaccharide chains, termed the alpha, beta, and gamma chains. We used Southern hybridization experiments on DNA isolated from various Neisseria spp. to determine if strains considered to be nonpathogenic possessed DNA sequences homologous with genes involved in the biosynthesis of these oligosaccharide chains. The presence or absence of specific genes was compared to the LOS profiles expressed by each strain, as characterized by their mobilities on sodium dodecyl sulfate-polyacrylamide gel electrophoresis gel and their reactivities with various LOS-specific monoclonal antibodies. A great deal of heterogeneity was seen with respect to the presence of genes encoding glycosyltransferases in Neisseria. All pathogenic species were found to possess DNA sequences homologous with the lgt gene cluster, a group of genes needed for the synthesis of the alpha chain. Some of these genes were also found to be present in strains considered to be nonpathogenic, such as Neisseria lactamica, N. subflava, and N. sicca. Some nonpathogenic Neisseria spp. were able to express high-molecular-mass LOS structures, even though they lacked the DNA sequences homologous with rfaF, a gene whose product must act before gonococcal and meningococcal LOS can be elongated. Using a PCR amplification strategy, in combination with DNA sequencing, we demonstrated that N. subflava 44 possessed lgtA, lgtB, and lgtE genes. The predicted amino acid sequence encoded by each of these genes suggested that they encoded functional proteins; however, structural analysis of LOS isolated from this strain indicated that the bulk of its LOS was not modified by these gene products. This suggests the existence of an additional regulatory mechanism that is responsible for the limited expression of these genes in this strain.

Structural and immunochemical characterization of the lipooligosaccharides expressed by Neisseria subflava 44

Neisserial lipooligosaccharides (LOSs) are a family of complex cell surface glycolipids. We used mass spectrometry techniques (electrospray ionization, collision-induced dissociation, and multiple step), combined with fluorophore-assisted carbohydrate electrophoresis monosaccharide composition analysis, to determine the structure of the two low-molecular-mass LOS molecules (LOSI and LOSII) expressed by Neisseria subflava 44. We determined that LOSI contains one glucose on both the alpha and beta chains. LOSII is structurally related to LOSI and differs from it by the addition of a hexose (either glucose or galactose) on the alpha chain. LOSI and LOSII were able to bind monoclonal antibody (MAb) 25-1-LC1 when analyzed by Western blotting experiments. We used a set of genetically defined Neisseria gonorrhoeae mutants that expressed single defined LOS epitopes and a group of Neisseria meningitidis strains that expresses chemically defined LOS components to determine the structures recognized by MAb 25-1-LC1. We found that extensions onto the beta-chain glucose of LOSI block the recognition by this MAb, as does further elongation from the LOSII alpha chain. The LOSI structure was determined to be the minimum structure that is recognized by MAb 25-1-LC1.

Association of AccI polymorphism in the follicle-stimulating hormone beta gene with polycystic ovary syndrome

OBJECTIVE

To search for FSH beta-subunit gene mutations in patients with polycystic ovary syndrome (PCOS) and determine the association between the mutations and the syndrome.

DESIGN

Clinical and molecular studies.

SETTING

Clinics and laboratories of the National University Hospital Obstetrics and Gynecology Department in Singapore.

PATIENT(S)

One hundred thirty-five patients with PCOS and 105 normal control subjects.

INTERVENTION(S)

Exons two and three were screened for mutations by single-stranded conformational polymorphism and DNA sequencing.

MAIN OUTCOME MEASURE(S)

Polymerase chain reaction followed by restriction enzyme analysis.

RESULT(S)

No missense mutation was found in the functional units of the FSHbeta gene in patients with PCOS, but a thymine-cytosine substitution in exon 3 (codon 76, TAT to TAC) was identified. The nucleotide change led to creation of an AccI digestion site. The distribution pattern of AccI polymorphism in the patients was significantly different from that in the control group, and the occurrence of homozygous carriers was significantly higher in patients (12.6%) than in the control group (3.8%). The frequency of polymorphism and prevalence of homozygosity were significantly higher in patients with PCOS with obesity (0.50% and 31.0%, respectively) than in those with menstrual disorders only (0.366% and 8.5%, respectively), which correlated with significantly higher androgen levels in the obese patients.

CONCLUSION(S)

The AccI polymorphism in FSHbeta gene may be associated with PCOS in some women, especially those with obesity.

Persistent, antigen-specific, therapeutic antitumor immunity by dendritic cells genetically modified with an adenoviral vector to express a model tumor antigen

Dendritic cells (DC) are potent antigen-presenting cells that play a critical role in the initiation of cellular immune responses. Using a BALB/c syngeneic colon carcinoma cell line expressing a model tumor antigen beta-galactosidase (betagal), we previously reported (Song et al, J Exp Med 1997; 186: 1247-1256) that immunization of mice with a single injection of DCs genetically modified with an adenovirus vector expressing betagal confers potent protection against a lethal intravenous tumor challenge, as well as suppression of pre-established lung tumors, resulting in a significant survival advantage. In the present study, we have addressed the question: how long does the memory of tumor antigen- specific immunity persists after DC priming in vivo using this genetically modified DC-based cancer vaccination strategy? To accomplish this, two groups of mice were evaluated: (1) mice surviving >400 days following protection from an initial intravenous tumor challenge after immunization with DC genetically modified to express betagal; and (2) mice surviving >300 days that had previously demonstrated regression of pre-established lung tumors after treatment with DC immunization. By analyzing the antigen-specific cytotoxic T lymphocyte response and challenging these long-term survival mice with a second subcutaneous tumor administration, the data demonstrate that a single administration of DC genetically modified to express a model antigen induces long-lasting, antigen-specific antitumor immunity in both naive and tumor-bearing hosts, observations that have important implications in the development of genetically modified DC-based antitumor vaccination strategies. Gene Therapy (2000) 7, 2080-2086.