[A retrospective cohort study of case fatality rate of HIV/AIDS cases and influencing factors in Jingzhou, Hubei Province, 1996-2021]

Objective: To analyze the case fatality rate of HIV/AIDS cases and influencing factors in Jingzhou. Methods: The data were retrieved from HIV/AIDS Comprehensive Response Information System and the cases diagnosed with HIV/AIDS in Jingzhou during 1996-2021 and aged 15 years or older were selected for the study. The death curve was drawn with Kaplan-Meier method, and Cox proportional-hazards model was used to identify influencing factors for death. Results: A total of 3 304 HIV/AIDS cases were followed up for 16 091.5 person-years, and 893 cases died, with a case fatality rate of 5.5/100 person-years. The cumulative case fatality rates of 1, 5 and 10 years were 15.4%, 25.0% and 34.6% respectively, the cumulative case fatality rates of 1, 5 and 10 years were 6.9%, 14.4% and 23.7% in the cases with access to antiretroviral therapy (ART), and 68.0%, 90.1% and 98.7% in the cases without access to ART. The results of Cox proportional hazards regression model showed that the risk for death was higher in those without access to ART than in those with access to ART (aHR=9.85, 95%CI: 8.19-11.85). The risk factors for death in those with access to ART included being men (aHR=1.64, 95%CI: 1.29-2.08), age ≥60 years old at diagnosis (aHR=3.52, 95%CI: 2.38-5.20), being infected by injecting drug use/others (aHR=2.38, 95%CI:1.30-4.34), being detected by medical institution (aHR=1.53, 95%CI: 1.11-2.11), CD4+T lymphocytes(CD4) counts <50 cells/μl (aHR=2.58, 95%CI: 1.87-3.58). The protective factor for death was high education level (high school and technical secondary school: aHR=0.64,95%CI:0.46-0.90; college and above: aHR=0.42, 95%CI: 0.24-0.73). The risk factors for HIV/AIDS death in those without access to ART included older age at diagnosis (30-44 years old: aHR=2.32, 95%CI: 1.40-3.84; 45-59 years old:aHR=2.61, 95%CI: 1.59-4.27; ≥60 years old: aHR=3.31, 95%CI: 2.01-5.47), lower CD4 counts (<50 cells/μl: aHR=10.47, 95%CI: 6.47-16.56; 50-199 cells/μl: aHR=2.31, 95%CI: 1.08-4.94; 200-349 cells/μl: aHR=2.35, 95%CI: 1.46-3.79). Conclusions: The case fatality rate of HIV/AIDS was relatively high in Jingzhou from 1996 to 2021, the first CD4 counts, ART and age at diagnosis were the major factors affecting HIV/AIDS death, "Expanding testing" and "prompt treatment upon diagnosis" should be continued and enhanced to improve the efficacy of ART and HIV/AIDS case survival.

Abstract B186: ITRI-2531 - A novel kinase inhibitor for treating hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers and is also a leading cause of cancer-related deaths worldwide. Until now, treatments for HCC remain limited, especially for the shortage of promising systemic therapies to replace systemic chemotherapy. Sorafenib, the first drug applied in targeted therapy for HCC, was approved and drew considerable attention. However, the efficacy and side effects of sorafenib are still unsatisfied, which make sorafenib far from ideal for treatment of HCC. Thus, developing novel therapeutics for HCC is necessary. A novel compound, ITRI-2531, is developed to improve the efficacy from sorafenib. ITRI-2531 shows cytotoxicity in HCC cell lines (Huh-7 and PLC/PRF/5) and patient-derived HCC tissue cell lines. In studies of kinase activities, ITRI-2531 suppresses the phosphorylation of MEK and ERK in PLC/PRF/5 cells and shows inhibition of multiple kinases (FLT3, FLT4, PDGFRA, PGDFRB, and VEGFR2) in KINOMEscanTM study. In in vivo studies, oral treatment of ITRI-2531 repressed subcutaneous Huh-7 and PLC/PRF/5 tumor growth in severe combined immunodeficient (SCID) mice and shows better efficacy than sorafinib. Moreover, ITRI-2531 prolongs the survival of SCID mice with orthotopic patient-derived xenograft tumor and suppresses alpha-fetoprotein in serum. On the other hand, ITRI-2531 also has good pharmacokinetic profiles. According to these results, we believe that ITRI-2531 warrants further evaluation as a new anti-HCC drug.

Citation Format: Tsung-Keng Kuo, On Lee, Mai-Wei Lin, Li-Zong Lin, Chun-Min Liu, Tai-ju Hsieh, Chun-Chung Wang, Shyh-Horng Lin, Chia-Ni Chang, Hui-Chun Hsu, Nien-Tzu Chou, Chin-Pen Lai, Chih-Hung Chen, Chia-Mu Tu, Shih-Ta Chen, Yuan-Jang Tsai, Chih-Peng Liu, Jenn-Tsang Hwang, Jui-Wen Huang, Yen-Chun Chen, Chrong-Shiong Hwang, Hsiang-Wen Tseng. ITRI-2531 - A novel kinase inhibitor for treating hepatocellular carcinoma. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B186.

RFX1-dependent activation of SHP-1 induces autophagy by a novel obatoclax derivative in hepatocellular carcinoma cells

Obatoclax is a small molecule which targets the Bcl-2 family, and is to treat leukemia, lymphoma and lung carcinoma. Previously, an obatoclax analogue, SC-2001, was found to disrupt the protein-protein interactions of the Bcl-2 family and also repress Bcl-XL and Mcl-1 expression via STAT3 inactivation. Here, we report a novel mechanism of autophagy induction by SC-2001 in liver cancer cells. The findings indicate that SC-2001 induced the autophagy marker LC3-II in four hepatocellular carcinoma (HCC) cells. Autophagosomes induced by SC-2001-treated cells were confirmed by electron microscopy. SC-2001 activated SHP-1, dephosphorylated STAT3 and Mcl-1, and subsequently released free beclin 1. Overexpression of STAT3 and Mcl-1 in PLC5 cells attenuated the induction of SC-2001 on autophagy. Abolishment of SHP-1 by a specific inhibitor aboragated the autophagic effects induced by SC-2001. In addition, it was further revealed that RFX-1, a transcription factor of SHP-1, is a critical regulator in SC-2001-mediated autophagy. Downregulation of RFX-1 by si-RNA protected cells from SC-2001-induced autophagy. Importantly, Huh7 tumor-bearing nude mice treated with SC-2001 showed downregulation of Mcl-1 and p-STAT3 protein expression and upregulation of SHP-1, LC3II, and RFX-1 protein expression. In summary, our data suggest that SC-2001 induces autophagic cell death in a RFX1/SHP-1/STAT3/Mcl-1 signaling cascade.

High-purity separation of cancer cells by optically induced dielectrophoresis

Detecting and concentrating cancer cells in peripheral blood is of great importance for cancer diagnosis and prognosis. Optically induced dielectrophoresis (ODEP) can achieve high resolution and low optical intensities, and the electrode pattern can be dynamically changed by varied light patterns. By changing the projected light pattern, it is demonstrated to separate high-purity gastric cancer cell lines. Traditionally, the purity of cancer cell isolation by negative selection is 0.9% to 10%; by positive selection it is 50% to 62%. An ODEP technology is proposed to enhance the purity of cancer cell isolation to about 77%.

Extra-pancreatic manifestations of IgG4-related systemic disease: a single-centre experience of treatment with combined immunosuppression

BACKGROUND/AIM

IgG4-related systemic disease (IgG4-RSD) is a systemic inflammatory disease distinguished by tissue infiltrates of IgG4(+) plasma cells and elevated serum IgG4 levels. While IgG4-RSD often involves the pancreas, extra-pancreatic organs are also frequently affected. Here, we review the presentation and management of patients with extra-pancreatic IgG4-RSD.

METHODS

A retrospective analysis was performed on patients diagnosed with extra-pancreatic IgG4-RSD identified from a single centre.

RESULTS

Six patients with extra-pancreatic IgG4-RSD were identified. The median age of the patients was 64 years. The range of involved organs included lymph nodes (three patients), ocular adnexa, lung, kidneys, meninges and exocrine glands. The median delay in diagnosis was 13.5 months (4-60 months). Four patients had elevated serum IgG4 levels at diagnosis. Five symptomatic patients were commenced on combination immunosuppression, which included corticosteroids. Maintenance therapy with azathioprine was used in one patient, methotrexate and mycophenolate were each used in two patients, and cyclophosphamide in one patient. Four treated patients went into remission, while two patients had persistent radiological disease. One patient experienced two relapses.

CONCLUSION

IgG4-RSD can manifest in a variety of organs. Lack of awareness regarding this entity may delay diagnosis. Combination treatment of corticosteroids and conventional immunosuppression is effective.

Differential effects of arsenic on calcium signaling in primary keratinocytes and malignant (HSC-1) cells

Arsenic is highly toxic to living cells, especially skin, and skin cancer is induced by drinking water containing arsenic. The molecular mechanisms of arsenic-induced cancer, however, are not well understood. To examine the initial processes in the development of arsenic-induced cancer, we analyzed calcium signaling at an early stage of arsenic treatment of human primary cells and compared the effects with those observed with arsenic treatment in carcinoma-derived cells. We found that arsenic inhibited inositol trisphosphate receptor (IP3R) function in the endoplasmic reticulum by inducing phosphorylation, which led to decreased intracellular calcium levels. Blockade of IP3R phosphorylation by the serine/threonine protein kinase Akt inhibitor wortmannin rescued calcium signaling. In contrast, arsenic treatment of cells derived from a carcinoma (human squamous carcinoma; HSC-1) for 1h had no obvious effect. Taken together, these results suggest that arsenic-induced reduction in calcium signaling is one of the initial mechanisms underlying the malignant transformation in the development of skin cancer.

Dovitinib induces apoptosis and overcomes sorafenib resistance in hepatocellular carcinoma through SHP-1-mediated inhibition of STAT3

The multiple kinase inhibitor dovitinib is currently under clinical investigation for hepatocellular carcinoma (HCC). Here, we investigated the mechanistic basis for the effects of dovitinib in HCCs. Dovitinib showed significant antitumor activity in HCC cell lines PLC5, Hep3B, Sk-Hep1, and Huh-7. Dovitinib downregulated phospho-STAT3 (p-STAT3) at tyrosine 705 and subsequently reduced the levels of expression of STAT3-related proteins Mcl-1, survivin, and cyclin D1 in a time-dependent manner. Ectopic expression of STAT3 abolished the apoptotic effect of dovitinib, indicating that STAT3 is indispensable in mediating the effect of dovitinib in HCC. SHP-1 inhibitor reversed downregulation of p-STAT3 and apoptosis induced by dovitinib, and silencing of SHP-1 by RNA interference abolished the effects of dovitinib on p-STAT3, indicating that SHP-1, a protein tyrosine phosphatase, mediates the effects of dovitinib. Notably, dovitinib increased SHP-1 activity in HCC cells. Incubation of dovitinib with pure SHP-1 protein enhanced its phosphatase activity, indicating that dovitinib upregulates the activity of SHP-1 via direct interactions. In addition, dovitinib induced apoptosis in two sorafenib-resistant cell lines through inhibition of STAT3, and sorafenib-resistant cells showed significant activation of STAT3, suggesting that targeting STAT3 may be a useful approach to overcome drug resistance in HCC. Finally, in vivo, dovitinib significantly suppressed growth of both Huh-7 and PLC5 xenograft tumors and downregulated p-STAT3 by increasing SHP-1 activity. In conclusion, dovitinib induces significant apoptosis in HCC cells and sorafenib-resistant cells via SHP-1-mediated inhibition of STAT3.

Carnitine and carnitine orotate affect the expression of the prolactin-releasing peptide gene

Carnitine is involved in fatty acid metabolism in mammals and is widely used as a nutritional supplement; carnitine orotate is a more absorbable form of carnitine. We investigated the effects of carnitine and carnitine orotate on mouse prolactin-releasing peptide (PrRP) mRNA expression. Twenty-four female mice were randomly divided into four groups of six; control mice were orally drenched with physiological saline solution (250 mg/kg body weight) and treatment mice were orally drenched with carnitine (250 mg/kg) or carnitine orotate (250 or 750 mg/kg), once a day, for 20 days from parturition. The carnitine or carnitine orotate was dissolved in saline solution before administration. The hypothalamus, pituitary and ovary were sampled on day 21 after parturition, and PrRP mRNA levels in these tissues were measured by semi-quantitative PCR, with glyceraldehyde 3-phosphate dehydrogenase as a control. Expression of PrRP in mice treated with carnitine and carnitine orotate was significantly increased in the ovary and significantly reduced in the pituitary gland. Compared with the control, hypothalamus PrRP mRNA increased significantly in the carnitine and low-dose carnitine orotate groups and decreased significantly in the high-dose carnitine orotate group. We conclude that carnitine and carnitine orotate regulate expression of PrRP in the pituitary gland and ovaries.

Association of the G-protein and α2-adrenergic receptor gene and plasma norepinephrine level with clonidine improvement of the effects of diuretics in patients with cirrhosis with refractory ascites: a randomised clinical trial

OBJECTIVE

Clonidine is an α(2)-adrenoceptor agonist which, by coupling with G-protein, has been proposed as an alternative treatment for refractory ascites of patients with cirrhosis for several years. Genetic polymorphisms of β-adrenoceptor and angiotensin II type 1 receptor blockers have been reported to affect drug response in patients with cirrhosis. This study evaluated the clonidine-diuretic response rate, favourable predictors and genetic components of the clonidine-diuretic response in patients with cirrhosis with refractory ascites.

METHODS

270 patients with cirrhosis with refractory ascites were randomised equally into two treatment groups to receive diuretics alone or the clonidine-diuretics association. The primary end point was clonidine-diuretic response rate. Secondary end points were mean daily dose of diuretics, times of paracentesis, ascites-related readmission and 1-year survival rate.

RESULTS

Good clonidine responders had better natriuresis and diuresis as well as a significant decrease in abdominal circumference, plasma renin, aldosterone and norepinephrine levels. The overall clonidine-diuretics response rate was 55-60%. In patients with cirrhosis, the prevalence of ARDA(2)C WD/DD and GNB3 CT/TT genotypes was 71% and 77%, respectively. Among the responders, 71% of patients with cirrhosis had the ARDA(2)C WD/DD genotype and 67% has the GNB3 CT/TT genotype. Besides higher baseline norepinephrine levels, the presence of both ARDA(2)C WD/DD and GNB3 CT/TT genotypes showed a positive predictive value of 82% and a negative predictive value of 79% for good clonidine response.

CONCLUSIONS

These results suggest that neurohormonal and genetic testing may be used as predictive factors for the additive effects of clonidine on the diuresis and natriuresis effects of diuretics in patients with cirrhosis with refractory ascites.

Abstract 3356: A controversial study on well reported liver cancer stem cell marker

Recent studies suggest that the presence of cancer stem cells (CSC) could be linked with patients’ survival. The ability of cancers to grow indefinitely has fueled the idea that cancer and stem cells may have common underlying mechanisms. It has been suggested that tumors are initiated from cancer stem cells (CSCs) with proliferation potential drives the growth of cancer. CSCs are resistant to chemotherapy and radiation. However, the suggested cancer stem cell markers in human hepatocellular carcinoma cells are variable and confused. In this study, we profiled some of the most reported CSC markers, including CD133, epithelial cell adhesion molecule (EpCAM), aldehyde dehydrogenase (ALDH), CD90, CD24, c-kit, global-H and stemness genes in eight human hepatocellular carcinoma cell lines. Through specific marker expressed cell sorting by FACs aria or magnetic beads, the CSC associated drug resistance and tumorigenicity were further evaluated. However, there is no obvious difference among parental group, marker-positive group and marker-negative group in these CSC characteristics evaluated. It seems no good correlation between reported markers in liver cancer stem cells. Therefore, presence of markers alone should be taken with caution as single prognostic parameters. Through harsh culture condition, spheroid cell grew and had been isolated, which perform CSC-like properties. Moreover, forced activation of an ESC-like gene expression program can reprogram HCC cells into CSC-like cells and achieve pathologic self-renewal. The ability to create induced cancer stem cells (iCSC) may provide opportunities to better define the biology of cancer stem cells in order to trace or eliminate them in human patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3356.

Malignancies associated with dermatomyositis and polymyositis in Taiwan: a nationwide population-based study

BACKGROUND

Previous studies showed that idiopathic inflammatory myopathies (IIM) carried an increased risk of cancers. However, no large-scale study of IIM has been conducted in the Chinese population.

OBJECTIVES

We sought to delineate the association of IIM and various cancer types from a nationwide database in Taiwan.

METHODS

We analysed the published national data from records of National Health Insurance claims. Cases of dermatomyositis (DM) and polymyositis (PM) from 2000 to 2005 and cancers registered in the catastrophic illness profile from 1997 to 2006 were collected. A nationally representative cohort of 1,000,000 enrollees was included for comparison.

RESULTS

In total, 136 patients (12.8%) among 1059 cases of DM and 46 persons (7.0%) among 661 cases of PM carried internal malignancies. Patients with DM tended to have cancers of nasopharynx, lung and breast. On the other hand, patients with PM tended to have breast, uterine cervix and lung cancers. Compared with the general population, DM gave a 10-fold increased risk for cancers, in which a 66-fold increased risk for nasopharyngeal carcinoma and a 31-fold increased risk for lung cancer were the two most significant. For patients with PM, a 6-fold increased risk for cancer was observed. Juvenile DM had a 16-fold increased risk for haematopoietic or lymphoid malignancy. Two thirds of comorbid malignancies were detected shortly after the diagnoses of IIM, within a mean of 1-2 years. Overall, younger patients with IIM carried the highest risk for malignancies, especially those in their twenties and thirties.

CONCLUSIONS

This is the first large-scale study to report the associated malignancies and the cancer risk of IIM in Taiwan.

Fourier analysis of surface plasmon waves launched from single nanohole and nanohole arrays: unraveling tip-induced effects

The authors report the investigation of surface plasmon waves (SPW) generated by single nanohole and nanohole arrays. Scattering-type scanning near-field microscopy is used to directly observe near-field distribution. The images after Fourier transformation display characteristic patterns that match with the derived analytic formula. The correspondence helps to identify the role of the scanning tip in generating SPW, making possible of the removal of this tip-induced effect. This study provides a means to perform in-depth investigation on surface plasmon polaritons.

Enhancing intensity of emitted light from a ring by incorporating a circular groove

We fabricated a ring containing a single circular groove (RCG) on silver film and which was supported on a glass substrate. We found that by changing the mean radius of the circular groove, the light intensity emitted from the RCG can be modulated by using the scattering light from the circular groove. In addition, we also fabricated circular grooves with the same depth but of different widths so that we could examine the scattering light behavior of the grooves. Herein, we propose a theoretical model which takes into account the amplitude modulation of the cylindrical waves. Our results showed that our proposed model agreed well with the experimental results.

How intravenous immunoglobulin is used in clinical practice: audits of two Sydney teaching hospitals

BACKGROUND

The clinical demand for i.v. immunoglobulin (IVIg) continues to increase in Australia for reasons that are not clear. IVIg is distributed for approved indications according to Australian Health Ministers' Advisory Council 2000 guidelines that are currently under review. IVIg may also be purchased by hospitals for uses not covered by these indications on an individual patient use basis. These audits were developed to examine current hospital practice in IVIg use.

METHODS

Six-month prospective audits of all IVIg use were conducted at two teaching hospitals in Sydney (Concord and Royal Prince Alfred Hospitals). Medical files and dispensing records were examined and compared with current guidelines.

RESULTS

One hundred and sixty-five recipients received 24,251 g of IVIg (mean total use 147 g/patient) for 36 distinct diagnoses, with 5.5% mortality. Drug committees supplied 1580 g of IVIg (6.5% of total product issued) to 12 recipients (7.3% of total recipients). The clinical specialties of immunology, haematology and neurology accounted for 92.9% of IVIg use, with 51.8% of overall use for replacement indications. Forty-two patients (25.5%) received IVIg for non-category 1 indications (4718 g, 19.5% of total product). Patients receiving IVIg for category 1 disorders had a 94.4% compliance with the guideline prerequisites where data were sufficient for assessment.

DISCUSSION

Our findings show a greater than expected proportion of non-category 1 IVIg use and substantial contributions from drug committees. Careful case selection within category 1 indications is evident in the high level of compliance with qualifying criteria. Current distribution procedures do not enable capture of outcome data to inform guideline revisions.

CONCLUSION

These audits emphasize the requirement for updated National Clinical Practice Guidelines, improved approval procedures, consensus statements in the specialties of immunology, haematology and neurology and clarification of the role of drug committees.

Cytokine gene polymorphisms in Chinese patients with psoriasis

BACKGROUND

Previous studies have shown that cytokine gene polymorphisms may confer susceptibility to psoriasis.

OBJECTIVES

To determine whether genetic polymorphisms of the cytokine genes might influence the development of psoriasis in Chinese patients in Taiwan.

METHODS

DNA samples were obtained from 170 patients with psoriasis vulgaris (PV), 102 patients with psoriatic arthritis (PsA) and 210 control subjects. Using direct sequencing and microsatellite genotyping, we examined 28 polymorphisms in 11 cytokine genes including the interleukin (IL)-1alpha, IL-1beta, IL-1 receptor antagonist, IL-4, IL-8, IL-10, IL-12B, IL-13, tumour necrosis factor (TNF)-alpha, TNF-beta and interferon-gamma genes. Genotypes of HLA-Cw*0602, killer cell immunoglobulin-like receptor (KIR) genes and major histocompatibility complex class I chain-related gene A (MICA) were also determined in patients with PsA.

RESULTS

The patients with PV were more likely to carry the +4496G allele of the IL-12B gene (59.4% vs. 49.3%, P = 0.0067, P(c) = 0.033). However, no significantly different allelic and genotypic distributions of the other analysed genes including IL-1beta, TNF-alpha, TNF-beta, KIR genes and MICA were found between the PV/PsA patients and controls. Moreover, no association was observed with disease onset, gender, peripheral arthritis or joint erosion. With regards to HLA-Cw*0602, its allele frequency was significantly increased in patients with early-onset PV (25.3% vs. 4.8%, P < 10(-7)), but not in patients with PsA.

CONCLUSIONS

The IL-12B gene polymorphism conferred a risk for PV in our Chinese population, although the effect was more minor than that of HLA-Cw*0602. Cw*0602, KIR2DS1/S2 and MICA-A9 were unlikely to be risk alleles in our patients with PsA. The other analysed genetic polymorphisms of cytokine genes do not appear to be associated with susceptibility to PV and PsA in Chinese patients in Taiwan.

Similarities and differences for light-induced surface plasmons in one- and two-dimensional symmetrical metallic nanostructures

Two types of double-sided nanostructure, one possessing a slit aperture with parallel grooves and the other possessing a circular aperture with concentric grooves, were fabricated to examine the similarities and differences of their diffraction behavior in one-dimensional (1-D) and two-dimensional (2-D) nanostructures. Based on the projection-slice theory, we conjecture that the surface plasmons in these two different nano-scale grooves possess similar modes. A localized surface plasmon (LSP) was used to examine the transmission characteristics induced by the apertures. The transmission characteristics of the slitted nanostructure and the circular nanostructure aperture were then measured. We coupled the transmission spectra measured from these two apertures with a 1-D parallel groove transmission curve simulated by a 1-D rigorous coupled wave analysis. Measured spectra results show reasonable agreement with the simulated data. We propose that the apparent blueshift observed in the peak frequency of a 2-D nanostructure is due to the difference in the shape of the aperture and the spot transmission characteristics of 1-D and 2-D systems as induced by a LSP.

Psoriasis vulgaris in Chinese individuals is associated withPSORS1C3andCDSNgenes

BACKGROUND

Besides the HLA-Cw*0602 allele, the psoriasis susceptibility 1 candidate 3 (PSORS1C3) and corneodesmosin (CDSN) genes are two probable psoriasis susceptibility genes in the PSORS1 locus. The -79C, -26C and +246A alleles of the PSORS1C3 gene, the CDSN*971T allele, CDSN*TTC (619T-1236T-1243C) and CDSN*5 (619T-1240G-1243C) are strongly associated with psoriasis in the caucasian population. Until now, no haplotype study of the PSORS1C3 and CDSN genes has been documented in Chinese patients with psoriasis vulgaris.

OBJECTIVES

We aimed to determine whether genetic polymorphisms of the PSORS1C3 and CDSN genes were associated with an increased risk of psoriasis vulgaris in Chinese patients in Taiwan.

METHODS

We investigated the PSORS1C3 and CDSN genes for disease association by direct sequencing in 178 patients with psoriasis vulgaris and 203 control subjects. Genotyping for HLA-Cw*0602, alpha-helix coiled-coil rod homologue (HCR) gene and single nucleotide polymorphism (SNP) n.9 was also carried out using a sequence-based typing method.

RESULTS

The PSORS1C3*582A allele, an SNP in the 3'-untranslated region of the PSORS1C3 gene, was a major psoriasis vulgaris susceptibility allele in the Chinese population, and the association was much stronger in patients with early-onset psoriasis vulgaris (22.3% vs. 6.9%, odds ratio = 3.87, P(c) =0.0000072). The frequencies of CDSN*TTC and CDSN*971T were also significantly increased in patients with early-onset psoriasis vulgaris. Moreover, PSORS1C3*582A, SNP n.9*C, Cw*0602 and HCR*WWCC were in near complete linkage disequilibrium (LD) with each other; in contrast, the LD with the CDSN gene was not so strong. SNP n.9*C-Cw*0602-PSORS1C3*582A-HCR*WWCC was a major susceptibility haplotype in patients with early-onset psoriasis vulgaris (P < 10(-7)) and this risk haplotype also carried CDSN*TTC and CDSN*971T.

CONCLUSIONS

The PSORS1C3 and CDSN genes are important psoriasis susceptibility genes in Chinese patients with psoriasis vulgaris.

No association of cytokine gene polymorphisms in Chinese patients with atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a common chronically relapsing skin disease associated with the activation of T-helper 2 cells. Recent studies have shown that polymorphisms in the genes for interleukin (IL)-4, the IL-4 receptor, IL-13, and signal transducer and activator 6 (STAT6) may contribute to susceptibility of AD. To date, no cytokine gene polymorphism study has been conducted on Chinese patients with AD.

AIMS

To determine whether genetic polymorphisms of the cytokine genes might influence the development of AD.

METHODS

DNA samples were obtained from 94 patients and 186 control subjects. Using direct sequencing and microsatellite genotyping, we examined 22 polymorphisms in eight cytokine genes including the genes for IL-4, -10, -12B and -13, the IL-4 receptor, tumour necrosis factor (TNF)-alpha, STAT6, and interferon (IFN)-gamma.

RESULTS

No significantly different allelic and genotypic distributions of the cytokine gene polymorphisms could be found between patients and controls. Moreover, no association was observed with disease onset, gender, the presence of elevated serum total IgE level or blood eosinophilia.

CONCLUSION

Our study suggests that the analysed genetic polymorphisms of cytokine genes do not appear to be associated with AD susceptibility in our Chinese population.

Beaming light from a subwavelength metal slit surrounded by dielectric surface gratings

In this article, we demonstrate that a subwavelength metal slit surrounded by dielectric surface gratings possesses a directional beaming effect. We propose a surface plasmon diffraction scheme to explain the three kinds of beaming conditions. The numerical simulations of the illustrative structures undertaken used a Finite Difference Time Domain (FDTD) Method and a Rigorous Coupled Wave Analysis (RCWA) Method. Our simulations were found to be consistent and in agreement with the experimental results. In comparison with other metal structures, we find that dielectric metal structures offer better performance as well as the advantage of being able to be efficiently mass produced for large volume industrial applications.

A study of PSORS1C1 gene polymorphisms in Chinese patients with psoriasis

BACKGROUND

Although genetic analyses have identified the HLA-Cw*0602 allele as the major risk allele for chronic plaque psoriasis in various ethnic groups, it has been proposed that the association of Cw*0602 is due to linkage disequilibrium and that other nearby genes are involved in susceptibility to psoriasis. The psoriasis susceptibility 1 candidate 1 (PSORS1C1, formerly SEEK1) gene, located 127 kb telomeric to the HLA-C locus, is considered to be one of the potential candidate genes of psoriasis. Up to the present, no association study of the PSORS1C1 gene has been conducted on Chinese patients with psoriasis.

OBJECTIVES

We aimed to determine whether the genetic polymorphisms of the PSORS1C1 gene were associated with an increased risk of psoriasis in Chinese patients.

METHODS

We investigated the PSORS1C1 gene for disease association by direct sequencing of the PSORS1C1 gene in 143 Chinese patients with chronic plaque psoriasis and 188 control subjects. Genotyping for HLA-Cw*0602 and the alpha-helix coiled-coil rod homologue (C6orf18, formerly HCR) gene was also carried out using a sequence-based typing method.

RESULTS

We identified 10 single nucleotide polymorphisms (SNPs) on the PSORS1C1 gene in our subjects; four of these SNPs cause amino acid change. We also detected poly(C) repeat variants from nucleotide positions 386-392 (poly(C)6-8). The poly(C) repeat polymorphisms cause a frame shift mutation. Another poly(C) repeat variant was also found at nucleotide positions 748-751. No significantly different allelic distributions of the PSORS1C1 SNPs or poly(C) repeat polymorphisms could be found between the patients with chronic plaque psoriasis and controls after correction for multiple testing. However, a significant increase of the Cw*0602 allele and tryptophan-tryptophan allele of the C6orf18 gene (HCR*WW) was found in patients with early onset psoriasis (21.9% vs. 4.8%, P < 10(-7)). Haplotype-based association analysis also showed a susceptibility haplotype carrying Cw*0602 and HCR*WW alleles in early onset Chinese patients.

CONCLUSIONS

Our results indicate that the PSORS1C1 gene might not play an important role in the causation of chronic plaque psoriasis in Chinese people.

Cytokine gene polymorphisms in bullous pemphigoid in a Chinese population

BACKGROUND

Bullous pemphigoid (BP) is an autoimmune bullous disease mostly associated with autoantibodies to the hemidesmosomal BP autoantigens BP180 and BP230. High levels of interleukin (IL)-1beta, IL-4, IL-5, IL-6, IL-8, IL-10, IL-13, tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma have been detected in skin lesions or sera of patients with BP. Cytokine gene polymorphisms may affect cytokine production and contribute to susceptibility to autoimmune diseases. Until now, no cytokine gene polymorphism study has been conducted on patients with BP.

OBJECTIVES

We aimed to determine whether the genetic polymorphisms of the cytokine genes might influence the development of BP.

METHODS

DNA samples were obtained from 96 BP patients and 174 control subjects. Using direct sequencing and microsatellite genotyping, we examined 23 polymorphisms in 11 cytokine genes including the IL-1alpha, IL-1beta, IL-1 receptor antagonist, IL-4, IL-6, IL-8, IL-10, IL-13, IL-4 receptor, TNF-alpha and IFN-gamma genes.

RESULTS

Although the BP patients were more likely to carry the -511T and -31C alleles of the IL-1beta gene (P = 0.04), the significance disappeared after correction for multiple testing (Pc). There was complete linkage disequilibrium between the -511T and -31C alleles of the IL-1beta gene. In female patients with BP, the associations with IL-1beta (-511T) and (-31C) alleles were much stronger (68% vs. 40.6%, odds ratio = 3.11, Pc = 0.006). No significantly different allelic and genotypic distributions of other cytokine gene polymorphisms could be found between the patients with BP and controls. Moreover, no association with the extent of disease involvement (localized or generalized) was observed.

CONCLUSIONS

The IL-1beta (-511) and (-31) polymorphisms were significantly associated with BP in women. The other genetic polymorphisms of cytokine genes that we analysed do not appear to be associated with BP susceptibility in our Chinese population.

Genetic polymorphisms of the HCR gene and a genomic segment in close proximity to HLA-C are associated with patients with psoriasis in Taiwan

BACKGROUND

Although psoriasis vulgaris (PV) is strongly associated with HLA-Cw*0602, it has been proposed that the association of Cw*0602 is due to linkage disequilibrium and that other nearby genes are involved in PV susceptibility. The alpha-helix coiled-coil rod homologue (HCR) gene, located 110 kb telomeric to the HLA-C locus, is presumed to be one of the PV candidate genes. Recently, a 10-kb genomic segment, centromeric to HLA-C, defined by two new single nucleotide polymorphisms (SNPs) n.7*A and n.9*C, was found to have a stronger association with psoriasis than the HCR gene. Until now, no study of the association of the HCR gene, SNPs n.7, and n.9 has been conducted on Chinese patients with psoriasis.

OBJECTIVES

We aimed to determine whether the genetic polymorphisms of the HCR gene, SNPs n.7*A, and n.9*C were associated with an increased risk of psoriasis in Chinese patients.

METHODS

Using direct sequencing of the HCR gene and the genomic region containing SNPs n.7 and n.9, we investigated the HCR gene, SNPs n.7, and n.9 for disease association in 115 Chinese patients with psoriasis and 103 control subjects. The HCR SNPs were confirmed by denaturing high performance liquid chromatography. Genotyping for HLA-Cw*0602 was also carried out using sequence-based typing.

RESULTS

We observed a different allelic distribution between patient and control groups at nucleotide positions 386, 404, 1802 and 2406 of the HCR gene, and SNPs n.7, and n.9. The associations were much stronger in early onset PV patients (for HCR-386*T and HCR-404*T, odds ratio = 5.63, Pc < 0.0001). The HLA-Cw*0602 also displayed a similar association with PV (odds ratio = 5.4, Pc < 0.0001). Moreover, SNP n.7*A, SNP n.9*C, Cw*0602, HCR-386*T, HCR-404*T and HCR-1802*T were in linkage disequilibrium with each other. Haplotype-based association analysis showed SNP n.7*A-SNP n.9*C-Cw*0602-HCR-386*T-HCR-404*T-HCR-1802*T-HCR-2406*G as a major susceptibility haplotype in this Chinese population (for early onset patients, odds ratio = 5.15, Pc < 0.0001).

CONCLUSIONS

Our results indicate that the HCR gene, SNP n.7*A, and SNP n.9*C as well as Cw*0602 are major susceptibility markers for psoriasis in Chinese patients.

SPR1 gene near HLA-C is unlikely to be a psoriasis susceptibility gene

Although genetics analyses have identified the HLA-Cw6 allele to be the major risk allele for psoriasis vulgaris (PV) in many racial groups, it has been proposed that other putative genes near the HLA-C locus are involved in PV susceptibility and that the association of Cw6 is a result of linkage disequilibrium. The SPR1 gene, a predicted gene located 128 kb telomeric to the HLA-C locus, is considered to be one potential candidate gene of PV. Until now, no association study of the SPR1 gene has been conducted on psoriasis patients. We investigated the SPR1 gene for disease association by direct sequencing of the SPR1 gene in 116 Chinese patients with PV and 116 normal subjects. Genotyping for HLA-Cw6 was also carried out using polymerase chain reaction/restriction fragment length polymorphism. Significant increase of the HLA-Cw6 allele was found in psoriasis patients (32.8% vs. 13.8%, P = 0.001). We found that the SPR1 gene is a highly polymorphic gene containing 13 single nucleotide polymorphisms (SNPs), two of which have not been previously reported, and four SNPs cause amino acid change. No significantly different allelic distribution of 13 SPR1 SNPs could be found between the patients with PV and controls after correction for multiple testing. If the frequencies of SPR1 SNPs were compared between the early onset psoriatics and control subjects, early onset patients were more likely to have G allele at position 988 (60% vs. 35.3%, P = 0.001). However, the significance disappeared upon stratification for the Cw6 status. Haplotype-based association analysis showed two susceptibility haplotypes (types 8 and 19) in early onset psoriasis patients. Nonetheless, the significance also disappeared after stratification of the Cw6 status. Our results suggest that HLA-Cw6 remains the major risk allele in Chinese psoriatics, and that the SPR1 gene might not play an important role in the causation of PV.

Community-acquired spontaneous bacterial meningitis in adult diabetic patients: an analysis of clinical characteristics and prognostic factors

BACKGROUND

We analyzed the clinical characteristics and prognostic factors of community-acquired spontaneous bacterial meningitis (CASBM) in adult diabetic patients.

PATIENTS AND METHODS

Over a period of 15 years, 47 adult diabetic patients with CASBM were identified. The clinical characteristics, laboratory data and therapeutic outcome of these 47 patients were statistically analyzed.

RESULTS

The 47 patients were 31 men and 16 women, aged 22 to 79 years, and they accounted for 38.5% (47/122) of our adult patients with culture-proven CASBM. The most common causative pathogen was Klebsiella pneumoniae (n = 32), followed by pathogens of the streptococcal species (n = 6). Besides classic manifestations of bacterial meningitis, bacteremia and focal suppuration, especially liver abscess, were common features in this group of patients. Liver cirrhosis and/or alcoholism were the other frequent underlying conditions. 27 patients survived in the course of therapy. The prognostic factors with statistical significance were glucose ratio and cerebrospinal fluid (CSF) white blood cell (WBC) count.

CONCLUSION

This study showed the high incidence of diabetes mellitus (DM) among the adult patients with CASBM in Taiwan. K. pneumoniae was the most frequent causative pathogen. Bacteremia and focal suppuration, especially liver abscess, were common findings. The values of glucose ratio and CSF WBC count had a statistically significant influence on the prognosis of our patients.

Suggestive evidence for linkage of schizophrenia to markers at chromosome 15q13-14 in Taiwanese families

In order to evaluate the linkage of schizophrenia to loci at chromosome 15q, we genotyped six microsatellite markers at chromosome 15q11-14 in 52 Taiwanese schizophrenic families. Two phenotype models (narrow: DSM-IV schizophrenia only; and broad: including schizophrenia, schizoaffective, and other nonaffective psychotic disorders) were used to define the disease phenotype. Maximum nonparametric linkage scores (NPL scores) of 3.33 (P = 0.0003) and 2.96 (P = 0.0008) were obtained at the marker D15S976 under broad and narrow models, respectively. Positive linkage results were also observed at the marker D15S1360, previously reported to have significant linkage to a neurophysiological deficit of schizophrenia, with NPL scores of 2.71 (P = 0.003) and 2.78 (P = 0.002) under broad and narrow models, respectively. The results provide suggestive linkage evidence of schizophrenia to loci at chromosome 15q13-14 in an ethnically distinct Taiwanese sample.

Linkage and mutation analysis in two Taiwanese families with long QT syndrome

Long QT syndrome (LQT) is a cardiovascular disorder causing syncope and sudden death from arrhythmias. Mutations in KCNQ1, KCNH2, KCNE1, KCNE2, and SCN5A genes encoding cardiac potassium and sodium ion channels cause LQT. Two Taiwanese LQT families were screened for mutations in these ion channel genes. In family H87, the diagnosis was made in the 25-year-old female proband and six family members based on recurrent syncope and/or a prolonged QT interval. Genotyping revealed a novel nonsense mutation, R744X (C to T transition in codon 744), in the KCNH2 potassium channel gene, resulting in truncation of the putative cyclic nucleotide-binding domain and C-terminal region of the HERG K(+)-channel in all affected family members. The mutation was confirmed by DdeI endonuclease digestion of the DNA from each family member. The 26-year-old female proband in family L89 developed repeated syncope with QTc of 0.61 seconds. After linkage and mutation analysis, the syndrome in this family was associated with a novel KCNQ1 missense mutation, T309I, causing the substitution of a threonine residue at position 309, in the pore region of the KvLQT1 K(+)-channel, with an isoleucine. By Tsp45I restriction analysis, the mutation was noted in the proband and the proband's asymptomatic brother, but was not detected in 100 unrelated normal individuals. Identification of a mutation has clinical implications for presymptomatic diagnosis and therapy.

Androgen-receptor gene CAG repeats, plasma testosterone levels, and risk of hepatitis B-related hepatocellular carcinoma

BACKGROUND

Worldwide, hepatocellular carcinoma (HCC) is more prevalent in men than in women, suggesting that sex hormones and/or X-chromosome-linked genes may be involved in hepatocarcinogenesis. We investigated the association of a trinucleotide (CAG) repeat in the androgen receptor (AR) gene (located on the X chromosome) termed "AR-CAG repeats," levels of plasma testosterone, and the risk of HCC in Taiwanese men. Chronic hepatitis B virus (HBV) infection, which is associated with risk of HCC, is hyperendemic in Taiwan.

METHODS

We compared the number of AR-CAG repeats in 285 HBV carriers with HCC and in 349 HBV carriers without HCC. We also conducted a nested case--control study on participants in a cohort study. Blood was collected prospectively from 110 case patients and 239 control subjects and was used to determine the number of AR-CAG repeats and plasma testosterone level. All statistical tests were two-sided.

RESULTS

The overall odds ratio (OR) for HCC was 1.72 (95% confidence interval [CI] = 1.03--2.89) for HBV carriers with 20 or fewer AR-CAG repeats compared with those with more than 24 repeats. This association was observed only in patients with late-onset HCC (OR = 2.37; 95% CI = 1.28--4.38). In the nested case-control study, HBV carriers in the highest tertile of testosterone levels had a statistically significantly increased risk of HCC (OR = 2.06; 95% CI = 1.14--3.70) compared with those in the lowest tertile. Elevated testosterone was more strongly associated with early-onset (OR = 4.67; 95% CI = 1.41--15.38) than late-onset disease. HBV carriers with 20 or fewer AR-CAG repeats and higher testosterone levels had a fourfold increase in HCC risk compared with those with more than 24 repeats and testosterone levels in the lowest tertile.

CONCLUSIONS

Higher levels of androgen signaling, reflected by higher testosterone levels and 20 or fewer AR-CAG repeats, may be associated with an increased risk of HBV-related HCC in men.

Power comparison of parametric and nonparametric linkage tests in small pedigrees

When the mode of inheritance of a disease is unknown, the LOD-score method of linkage analysis must take into account uncertainties in model parameters. We have previously proposed a parametric linkage test called "MFLOD," which does not require specification of disease model parameters. In the present study, we introduce two new model-free parametric linkage tests, known as "MLOD" and "MALOD." These tests are defined, respectively, as the LOD score and the admixture LOD score, maximized (subject to the same constraints as MFLOD) over disease-model parameters. We compared the power of these three parametric linkage tests and that of two nonparametric linkage tests, NPLall and NPLpairs, which are implemented in GENEHUNTER. With the use of small pedigrees and a fully informative marker, we found the powers of MLOD, NPLall, and NPLpairs to be almost equivalent to each other and not far below that of a LOD-score analysis performed under the assumption the correct genetic parameters. Thus, linkage analysis is not much hindered by uncertain mode of inheritance. The results also suggest that both parametric and nonparametric methods are suitable for linkage analysis of complex disorders in small pedigrees. However, whether these results apply to large pedigrees remains to be answered.

Ca(2+) mobilization evoked by chloroform in Madin-Darby canine kidney cells

The effect of chloroform on Ca(2+) mobilization in Madin-Darby canine kidney cells was examined by using Fura-2 as a Ca(2+) probe. Chloroform (24-248 mM) concentration dependently increased intracellular Ca(2+) concentration ([Ca(2+)](i)). Ca(2+) removal inhibited the Ca(2+) signals evoked by 93 to 248 mM chloroform by reducing both the initial rise and the sustained phase. In Ca(2+)-free medium, pretreatment with 93 mM chloroform abolished the Ca(2+) release induced by 1 microM thapsigargin, an endoplasmic reticulum Ca(2+) pump inhibitor, and partially reduced the Ca(2+) release induced by 2 microM carbonylcyanide m-chlorophenylhydrazone, a mitochondrial uncoupler. Pretreatment with carbonylcyanide m-chlorophenylhydrazone and thapsigargin to deplete the Ca(2+) stores in mitochondria and the endoplasmic reticulum, respectively, only partially inhibited chloroform-induced Ca(2+) release. This suggests that chloroform released Ca(2+) from multiple internal pools. The addition of 3 mM Ca(2+) increased [Ca(2+)](i) after pretreatment with 93 mM chloroform in Ca(2+)-free medium. La(3+) (1 mM) partially inhibited the [Ca(2+)](i) increase induced by 93 mM chloroform. Chloroform (93 mM)-induced Ca(2+) release was not altered when the formation of inositol-1,4,5-trisphosphate was abolished by U73122 (2 microM), a phospholipase C inhibitor, but was inhibited by 90% by inhibition of phospholipase A(2) with 40 microM aristolochic acid. Collectively, we found that 93 mM chloroform increased [Ca(2+)](i) in Madin-Darby canine kidney cells by releasing Ca(2+) from multiple stores in a manner independent of the formation of inositol-1,4,5-trisphosphate, followed by Ca(2+) entry from external medium. Other solvents, such as ethanol, methanol, and DMSO, did not affect the resting [Ca(2+)](i) at a concentration of 248 mM.

Evaluation of linkage of markers on chromosome 6p with schizophrenia in Taiwanese families

Previous studies have indicated possible linkage of schizophrenia with chromosome 6p21-24. In an attempt to replicate these findings, we studied the linkage of schizophrenia with nine markers on chromosome 6p21-24 in 39 Taiwanese schizophrenic nuclear families with at least two affected siblings. Two diagnostic models (narrow: Diagnostic and Statistical Manual of Mental Disorders-IV schizophrenia only; and broad: including schizophrenia, schizoaffective, and other nonaffective psychotic disorders) were used to define the disease phenotypes. With the broad and narrow diagnostic models, the marker D6S296 produced maximum two-point lod scores of 1.46 (straight theta = 0.2) and 1.35 (straight theta = 0. 2), respectively, in the recessive inheritance model. Assuming locus heterogeneity, a multipoint lod score of 0.85 was obtained between markers D6S296 and D6S277 under the narrow/recessive model. Maximum nonparametric lod scores of 1.25 ( p= 0.09) and 1.36 (p = 0.08) were observed, but still not statistically significant, at D6S296 in the narrow and broad diagnostic models, respectively. Both two-point analysis of the dominant model (lod score 0.85) and nonparametric analysis (lod score 1.25) showed a mild peak lod score appeared at marker D6S 285 as well. The results add some support to the suggestive linkage of schizophrenia with markers in the regions of chromosome 6p22 and 6p24 in an ethnically distinct Taiwanese sample. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:74-78, 2000.

Failure to exclude a possible schizophrenia susceptibility locus on chromosome 13q14.1-q32 in southern African Bantu-speaking families

Several recent reports have provided evidence suggesting linkage of markers on chromosome 13q14.1-q32 to schizophrenia in families from England, Wales, Japan and the USA, but not in Chinese families. We tested for linkage between markers in this region and schizophrenia in a sample of 16 families multiply affected with schizophrenia drawn from the Bantu-speaking black population of South Africa. Twelve markers spanning 76 cM of chromosome 13q were examined in these analyses, including 10 markers covering the most positive region in the studies of the English, Welsh and Chinese families, and two additional markers yielding the largest positive LOD scores in the American study. The map of markers used was D13S126-14.6cM-D13S119-12.2cM-D13S144-10.+ ++2cM-D13S160-7.9cM-D13S121-6.3cM -D13S71-1.6cM-D13S122- 4.9cM-D13S128-8.9cM-D13S770-1.4cM-D13S7 79-2.2cM-D13S64-7.4cM-D13S173. Parametric two-point analysis yields strongly negative LOD scores across the region D13S71-D13S64 under all models, and D13S71-D13S173 under a recessive model, when analysing either the whole sample or affected individuals only. ALOD maxima are 0.0 when allowing for heterogeneity for all markers in this subset. Under recessive modelling, the ALOD maximum is 0.717, theta = 0.0, alpha = 0.45, for D13S126 when analysing all samples. Affected-only analysis of this marker yields a maximum LOD score of 0.645, theta = 0.1, and an ALOD maximum of 0.697, theta = 0.0, alpha = 0.55. Non-parametric multipoint analysis of these markers provides no support for excess sharing of alleles identical by descent, although D13S119 and D13S770 show some evidence for excess sharing of alleles identical by state.

Persistence of porcine reproductive and respiratory syndrome virus in intensive farrow-to-finish pig herds

An epidemiological study of porcine reproductive and respiratory syndrome (PRRS) within pig herds was conducted in 8 intensive farrow-to-finish pig farms. Persistence of PRRS virus (PRRSV) in pig herds was demonstrated by regular postmortem examination on 2 farms for a period of 2 y. Virus isolation and serum neutralization (SN) tests were performed on the sera collected from 9 groups of pigs (10 pigs/group) of various ages on 8 pig farms. Except for 1 farm, isolation rates of PRRSV reached the highest level of 70 to 100% of pigs 6 to 8 wk of age, which coincided with the lowest levels of maternal immunity. In 1 pig herd, sows (39 in total) with SN titers of < or = 1:2, 1:4-1:8, and > or = 1:16 were designated as groups 1, 2, and 3, respectively. Sera were obtained from their progeny (3 pigs randomly selected from each litter) at various ages from 0 to 22 weeks. A positive correlation (r = 0.377, P < 0.001) between the SN titers of sows and those of their progeny (1-week-old piglets) was observed. Pigs at the age of 6 wk, only 7.9% of group 1 pigs compared to 72.4% of group 3 pigs were seropositive. A significant difference (P < 0.01) in the percentage of pigs with PRRSV viremia among the 3 groups was observed, with the lowest level found in group 3 pigs. The isolation rates of PRRSV from serum reached the maximum at the age of 9 wk for all 3 groups. The results indicated that passively acquired serum antibodies conferred a protective effect for piglets; however, loss of passive immunity at various ages of pigs produced susceptible pigs that resulted in PRRSV persistence in the pig herds. Pigs 6 to 9 weeks old were the major reservoir for PRRSV in farrow-to-finish pig herds.

Suggestive evidence for linkage of schizophrenia to markers on chromosome 13 in Caucasian but not Oriental populations

Previously we reported suggestive evidence for linkage of schizophrenia to markers on chromosome 13q14.1-q32. We have now studied an additional independent sample of 44 pedigrees consisting of 34 Taiwanese, 9 English and 1 Welsh family in an attempt to replicate this finding. Narrow and broad models based on Research Diagnostic Criteria or the Diagnostic and Statistical Manual of Mental Disorders, third edition, revised, were used to define the schizophrenia phenotype. Under a dominant genetic model, two-point lod scores obtained for most of the markers were negative except that marker D13S122 gave a total lod score of 1.06 (theta = 0.2, broad model). As combining pedigrees from different ethnic origins may be inappropriate, we combined this replication sample and our original sample, and then divided the total sample into Caucasian (English and Welsh pedigrees) and Oriental (Taiwanese and Japanese pedigrees) groups. The Caucasian pedigrees produced maximized admixture two-point lod scores (A-lod) of 1.41 for the marker D13S119 (theta = 0.2, alpha = 1.0) and 1.54 for D13S128 (theta = 0, alpha = 0.3) with nearby markers also producing positive A-lod scores. When five-point model-free linkage analysis was applied to the Caucasian sample, a maximum lod score of 2.58 was obtained around the markers D13S122 and D13S128, which are located on chromosome 13q32. The linkage results for the Oriental group were less positive than the Caucasian group. Our results again suggest that there is a potential susceptibility locus for schizophrenia on chromosome 13q14.1-q32, especially in the Caucasian population.

Suggestive evidence for linkage of schizophrenia to markers on chromosome 13q14.1-q32

Family, twin and adoption studies highlight the influence of genes in the aetiology of schizophrenia, though the mode of inheritance is unclear. We have been conducting a systematic search for major genes in schizophrenia using a series of multiply affected families and report preliminary results of linkage under heterogeneity with markers on chromosome 13. A lod2 score of 1.61 for marker D13S144 was obtained at theta = 0 and alpha of 0.5 and nearby markers also produced positive values.