Prevalence of dentine hypersensitivity in Chinese rural adults with dental fluorosis

The aim of this study was to estimate the prevalence of dentine hypersensitivity (DH) among residents of rural China with dental fluorosis aged 30-69 years. A village located in northern China in which dental fluorosis was common was selected. Some 1250 residents with fluorosis ranging in age from 30 to 69 years completed a structured questionnaire and underwent clinical examination. Diagnosis of DH was based on the combination of the subject's self-evaluation and clinical examination. Dental fluorosis was evaluated using Dean's index (DI). In the village, the fluoride concentration in drinking water was 1.15-1.50 mg L(-1) . The community fluorosis index was 1.47, and 74 (9.7%) of the participants with dental fluorosis were diagnosed with DH. There was no significant difference between men and women. DH was most commonly observed in the lower incisors, and the most common cause of DH was cold stimulation. Logistic regression analysis showed acid reflux to be the only risk factor for DH in the current study. Among subjects with DH, none took treatment measures, visited a hospital or clinic, or used antisensitivity toothpaste. The prevalence of DH in the selected subjects with dental fluorosis was 9.7%. Acid reflux was found to be a risk factor for DH in the current study.

A novel single nucleotide polymorphism in the protein tyrosine phosphatase N22 gene (PTPN22) is associated with Type 1 diabetes in a Chinese population

AIMS

To examine single nucleotide polymorphisms in the protein tyrosine phosphatase N22 gene (PTPN22) and to study their association with Type 1 diabetes in a Chinese cohort.

METHODS

Three hundred and sixty-four young patients with Type 1 diabetes and 719 healthy children were included in this case-controlled study. The genotypes of rs1217385, rs2488457 (-1123C>G), rs1217414, rs1217419, rs3765598 and rs2476601 (1858C>T) in the PTPN22 gene were determined using the SNaPshot method. Alleles, genotypes and haplotype frequencies were compared between patients with Type 1 diabetes and healthy control subjects. The association between single nucleotide polymorphisms and clinical traits/autoantibody status was also analysed.

RESULTS

The single nucleotide polymorphism, rs1217419, located in the second intron of the PTPN22 gene was associated with Type 1 diabetes (odds ratio 1.5, 95% CI 1.14-1.97, P = 0.003). An additional single nucleotide polymorphism, rs1217385, was also associated with Type 1 diabetes; however, the association was secondary to that of rs1217419. The previously reported single nucleotide polymorphism that is associated with Type 1 diabetes (-1123G>C) had only marginal association with Type 1 diabetes in our study. A marginal association was also identified between -1123G>C and glutamic acid decarboxylase autoantibody positivity in patients with Type 1 diabetes. There was no association between the single nucleotide polymorphism 1858C>T and Type 1 diabetes in our studied cohort.

CONCLUSIONS

Our study confirmed that PTPN22 is a gene that contributes to Type 1 diabetes susceptibility. The primary association occurs with single nucleotide polymorphism rs1217419 and there is clear heterogeneity of the association between PTPTN22 polymorphisms and Type 1 diabetes in a Chinese population compared with other populations.

Estrogen receptor α variants affect age at onset of Alzheimer's disease in a multiethnic female cohort

BACKGROUND/AIMS

Few studies of gene variants that affect estrogen activity investigate their association with age at onset of Alzheimer's disease (AD) in women of different ethnicities. We examined the influence of ESR1 polymorphisms on age at onset of AD in a multiethnic cohort of women.

METHODS

Among 1,436 women participating in the Washington Heights Inwood Columbia Aging Project, association with age at AD onset was assessed for 41 single-nucleotide polymorphisms (SNPs) on the ESR1 gene using Cox proportional hazard models, adjusting for presence of an APOE ε4 allele, years of education, and body mass index.

RESULTS

Six SNPs in self-identified White women were protectively associated with delayed age of AD onset in this self-identified group, including the two restriction fragment length polymorphisms PvuII (rs2234693) and XbaI (rs9340799) (HR range = 0.420-0.483). Two separate SNPs were found to affect age of AD onset in self-identified Black women.

CONCLUSIONS

ESR1 polymorphisms affect age of onset of AD in women, and risk alleles vary by ethnicity. These effects are possibly due to different linkage disequilibrium patterns or differences in comorbid environmental or cultural risk factors mediating the SNP effect on risk for AD.

Increased Rate of Sporadic and Recurrent Rare Genic Copy Number Variants in Parkinson's Disease Among Ashkenazi Jews

To date, only one genome-wide study has assessed the contribution of copy number variants (CNVs) to Parkinson's disease (PD). We conducted a genome-wide scan for CNVs in a case–control dataset of Ashkenazi Jewish (AJ) origin (268 PD cases and 178 controls). Using high-confidence CNVs, we examined the global genome wide burden of large (≥100 kb) and rare (≤1% in the dataset) CNVs between cases and controls. A total of 986 such CNVs were observed in our dataset of 432 subjects. Overall global burden analyses did not reveal significant differences between cases and controls in CNV rate, distribution of deletions or duplications or number of genes affected by CNVs. Overall deletions (total CNV size and ≥2× frequency) were found 1.4 times more often in cases than in controls (P = 0.019). The large CNVs (≥500 kb) were also significantly associated with PD (P = 0.046, 1.24-fold higher in cases than in controls). Global burden was elevated for rare CNV regions. Specifically, for OVOS2 on Chr12p11.21, CNVs were observed only in PD cases (n = 7) but not in controls (P = 0.028) and this was experimentally validated. A total of 81 PD cases carried a rare genic CNV that was absent in controls. Ingenuity pathway analysis (IPA) identified ATXN3, FBXW7, CHCHD3, HSF1, KLC1, and MBD3 in the same disease pathway with known PD genes.

Analyses of FLG mutation frequency and filaggrin expression in isolated ichthyosis vulgaris (IV) and atopic dermatitis-associated IV

BACKGROUND

Ichthyosis vulgaris (IV; OMIM 146700) is a very common inherited skin disorder. Loss-of-function mutations in the filaggrin gene (FLG) have been identified as the cause of IV. In a previous study, we found that the percentage of FLG null mutations was lower in IV associated with atopic dermatitis (AD) than in IV not associated with AD (isolated IV). We speculated that some clinical manifestations of IV in patients with AD are not induced by FLG mutations.

OBJECTIVES

In order to clarify this issue, we collected 21 IV pedigrees, 33 patients with sporadic isolated IV and 116 patients with AD-associated IV to analyse FLG mutation frequency and filaggrin expression in isolated IV and AD-associated IV.

METHODS

A comprehensive sequencing of the FLG gene in all patients was performed using an overlapping polymerase chain reaction (PCR) strategy. We also studied the immunohistochemistry of profilaggrin/filaggrin protein expression in the skin and measured the mRNA expression using real-time PCR in seven patients, including one patient with IV harbouring the mutation c.3321delA, two patients with AD-associated IV harbouring c.3321delA and c.6834del5, and four patients with AD-associated IV without FLG mutations.

RESULTS

The percentage of mutations in the FLG gene was 74% and 43% in patients with isolated IV and patients with AD-associated IV, respectively. Immunohistochemical staining revealed that profilaggrin/filaggrin peptides were remarkably reduced in the epidermis of all the patients. All the patients with either AD or IV showed lower FLG mRNA expression compared with the normal control.

CONCLUSIONS

These results indicate that factors other than FLG gene mutations can downregulate profilaggrin/filaggrin expression, leading to the ichthyosiform phenotype in the context of AD.

Aromatase variants modify risk for Alzheimer's disease in a multiethnic female cohort

BACKGROUND/AIMS

Few studies of gene variants that affect estrogen activity investigate their association with risk for Alzheimer's disease (AD) in women of different ethnicities. We investigated the influence of CYP19 polymorphisms on risk for AD in a multiethnic cohort of women, with individual ethnicity assessed by genetic population ancestry informative markers (AIMs) as well as by self-identified ethnicity.

METHODS

Among 1,686 women participating in the Washington Heights Inwood Columbia Aging Project, association with risk for AD was assessed for 41 single nucleotide polymorphisms (SNPs) on the CYP19 gene using multivariable logistic regression, adjusting for age, presence of an APOE ε4 allele, years of education, and body mass index.

RESULTS

Risk for AD was associated with 6 SNPs in women of predominantly Caucasian AIMs-defined ancestry. Of these, 2 were also associated with decreased risk of AD in women of admixed/Hispanic AIMs ancestry. Two separate SNPs were found to be protective in women of predominantly African AIMs-based ancestry.

CONCLUSIONS

CYP19 polymorphisms affect risk for AD in women, and risk alleles vary by AIMs-defined ancestry. These effects are possibly due to linkage disequilibrium patterns or differences in the prevalence of comorbid risk factors mediating the SNP effect on risk for AD by group.

Challenges and solutions in the development of genomic biomarker panels: a systematic phased approach

In the post-genome era, high throughput gene expression profiling has been successfully used to develop genomic biomarker panels (GBP) that can be integrated into clinical decision making. The development of GBPs in the context of personalized medicine is a scientifically challenging and resource-intense process. It needs to be accomplished in a systematic phased approach to address biological variation related to a clinical phenotype (e.g. disease etiology, gender, etc.) and minimize technical variation (noise). Here we present the methodological aspects of GBP development based on the experience of the Cardiac Allograft Rejection Gene Expression Observation (CARGO) study, a study that lead to the development of a molecular classifier for rejection screening in heart transplant patients.

Loss of heterozygosity on chromosome 14 in primary nasopharyngeal carcinoma

Multiple genetic alterations are believed to be involved in the pathogenesis of nasopharyngeal carcinomas (NPC). Loss of heterozygosity (LOH) of chromosomes 3p, 9p and 11q were previously reported in NPC. In order to further define the genetic alterations in NPC, 42 pairs of normal and tumor DNA of NPC were examined for LOH on chromosomes 5p, 5q, 6q, 14q, 15q, 16p, 16q, 17q using 16 polymorphic microsatellite markers. Frequent LOH (33%; 7 out of 21 cases) was observed in chromosome 14q at locus D14s81 (14q31). In order to define the common region of deletion, nine polymorphic microsatellite markers on 14q were examined for LOH in NPC. A common region of deletion was defined in NPC at chromosome 14q24.3-q32.1 flanked by two microsatellite markers D14s76 and D14s45. The common region of deletion (14q24.3-32.1) identified in NPC overlapped with the deleted regions of 14q reported in several human cancers. In 2 cases of NPC, the pattern of LOH revealed the presence of another commonly deleted region defined by loci D14s63 and D14s69 (mapped to 14q11.1-24.1) and located proximal to locus D14s76(14q24.3). This study suggests that multiple tumor suppressor genes present on chromosome 14q are involved in the pathogenesis of NPC.

Mutations analysis in filaggrin gene in northern China patients with atopic dermatitis

BACKGROUND

Recently, we have reported filaggrin mutations (FLG) of atopic dermatitis in southern China. However, there have been few detailed reports of FLG mutations of patients with AD in northern China by now.

OBJECTIVES

The present aim was to establish the mutation spectrum of FLG gene in AD patients in northern China.

METHODS

A total of 339 cases met Hanifin and Rajka diagnostic criteria of AD were recruited. A comprehensive sequencing of the entire FLG coding region in these patients was conducted. All detected FLG null mutations were screened in a cohort of 301 normal controls.

RESULTS

Seven novel mutations (478insA, Q1070X, 4026delT, Q1712X, Q2397X, 7145del4 and 8001del4) and eleven reported mutations (3222del4, 3321delA, 4271delAA, S1515X, Q1790X, 5757del4, 6834del5, Q2417X, E2422X, 7945delA and K4671X) in AD were identified. Mutations 3321delA and K4671X were two of the most common mutations in AD. FLG null mutations were present in 26.0% of AD patients. FLG null alleles (compound genotypes) were significantly higher in AD (P < 0.001) than in the controls. The compound genotypes for all FLG variants were significantly associated with IV (P < 0.001) and palmar hyperlinearity (P < 0.001). The common mutation, K4671X, was significantly associated with AD-coexistent allergic rhinitis (P = 0.005).

CONCLUSIONS

Our study increases the total number of FLG mutations. We clearly demonstrated that FLG loss-of-function mutations were significantly associated with AD in northern China. The FLG null mutations in the Chinese population differed not only from that in the European population but also from that in sub-populations of Asians outside of the Chinese mainland.

Implication of dysregulation of the canonical wingless-type MMTV integration site (WNT) pathway in diabetic nephropathy

AIMS/HYPOTHESIS

The wingless-type MMTV integration site (WNT) pathway mediates multiple physiological and pathological processes, such as inflammation, angiogenesis and fibrosis. The aim of this study was to investigate whether canonical WNT signalling plays a role in the pathogenesis of diabetic nephropathy.

METHODS

Expression of WNT ligands and frizzled receptors in the canonical WNT pathway in the kidney was compared at the mRNA level using real-time RT-PCR between Akita mice, streptozotocin-induced diabetic rats and db/db mice and their respective non-diabetic controls. Renal function was evaluated by measuring the urine albumin excretion. Human renal proximal tubular epithelial cells were treated with high-glucose medium and 4-hydroxynonenal (HNE). Levels of β-catenin, connective tissue growth factor and fibronectin were determined by western blot analysis.

RESULTS

Some of the WNT ligands and frizzled receptors showed increased mRNA levels in the kidneys of Akita mice, streptozotocin-induced diabetic rats and db/db mice compared with their non-diabetic controls. Renal levels of β-catenin and WNT proteins were upregulated in these diabetic models. Lowering the blood glucose levels by insulin attenuated the activation of WNT signalling in the kidneys of Akita mice. In cultured human renal proximal tubular epithelial cells, both high glucose and HNE activated WNT signalling. Inhibition of WNT signalling with a monoclonal antibody blocking LDL-receptor-related protein 6 ameliorated renal inflammation and fibrosis and reduced proteinuria in Akita mice.

CONCLUSIONS/INTERPRETATION

The WNT pathway is activated in the kidneys of models of both type 1 and 2 diabetes. Dysregulation of the WNT pathway in diabetes represents a new pathogenic mechanism of diabetic nephropathy and renders a new therapeutic target.

The effect of lysophosphatidic acid and Rho-associated kinase patterning on adhesion of dental pulp cells

AIM

To investigate the effects of lysophosphatidic acid (LPA) and the Rho/Rho-associated kinase (ROCK) pathway on adhesion of dental pulp cells (DPCs).

METHODOLOGY

Human DPCs were cultured ex vivo. After treatment of LPA and Y-27632, a specific ROCK inhibitor, changes in focal contacts (FCs) were examined by immunofluorescent staining. Activation of FCs proteins was examined by measuring tyrosine 397 phosphorylation of focal adhesion kinase (FAK) and paxillin using immunoblotting. The data were analysed by Student's t-test.

RESULTS

The immunofluorescent staining indicated LPA stimulation induced larger focal adhesion in the cell periphery, compared with the control. Inhibition of ROCK by Y-27632 decreased the formation of FCs markedly, even in the LPA-stimulated cells. LPA also increased the level of tyrosine phosphorylation of paxillin at 30min (P<0.05) and FAK at 5 and 30min (P<0.05). Furthermore, p-paxillin levels declined immediately after Y-27632 treatment and remained low at 5, 30, 60min. Y-27632 also suppressed the effects of LPA on p-paxillin and p-FAK at 5 and 30min (P<0.05).

CONCLUSION

LPA activated Rho and then subsequently activated ROCK, suggesting that LPA influences the FCs of DPCs by modulating tyrosine phosphorylation of FAK and paxillin via the Rho/ROCK pathway.

Extended criteria donor and severe intraoperative glucose variability: association with reoperation for hemorrhage in liver transplantation

Reoperations for hemorrhage following liver transplantation (OLT) are commonly associated with increased morbidity and mortality. We sought to determine the incidence and risk factors for reoperation for hemorrhage among adult liver transplantations. We retrospectively analyzed 668 patients transplanted between January 2004 and November 2007. Within 30 days following transplantation one hundred eleven patients (16.6%) underwent 156 reoperations for hemorrhage, averaging 1.4 reoperations per patient. More than half of the reoperations occurred during the first 2 postoperative days. One-third of patients required 2 or more reoperations. Multivariate logistic regression analysis showed 4 independent risk factors: grafts from donors with multiple extended criteria, severe intraoperative glucose variability, intraoperative use of vasopressors, and red blood cell transfusion requirement. In conclusion, we identified several independent risk factors for reoperation due to hemorrhage following OLT. Avoidance of severe intraoperative glucose variability and careful evaluation of the benefits and risks of utilizing extended criteria donors must be considered before transplantation.

Lipopolysaccharide-induced dental pulp cell apoptosis and the expression of Bax and Bcl-2 in vitro

Lipopolysaccharide exerts many effects on many cell lines, including cytokine secretion, and cell apoptosis and necrosis. We investigated the in vitro effects of lipopolysaccharide on apoptosis of cultured human dental pulp cells and the expression of Bcl-2 and Bax. Dental pulp cells showed morphologies typical of apoptosis after exposure to lipopolysaccharide. Flow cytometry showed that the rate of apoptosis of human dental pulp cells increased with increasing lipopolysaccharide concentration. Compared with controls, lipopolysaccharide promoted pulp cell apoptosis (P < 0.05) from 0.1 to 100 μg/mL but not at 0.01 μg/mL. Cell apoptosis was statistically higher after exposure to lipopolysaccharide for 3 days compared with 1 day, but no difference was observed between 3 and 5 days. Immunohistochemistry showed that expression of Bax and Bcl-2 was enhanced by lipopolysaccharide at high concentrations, but no evident expression was observed at low concentrations (0.01 and 0.1 μg/mL) or in the control groups. In conclusion, lipopolysaccharide induced dental pulp cell apoptosis in a dose-dependent manner, but apoptosis did not increase with treatment duration. The expression of the apoptosis regulatory proteins Bax and Bcl-2 was also up-regulated in pulp cells after exposure to a high concentration of lipopolysaccharide.

Fine mapping of QTL for prepulse inhibition in LG/J and SM/J mice using F(2) and advanced intercross lines

Prepulse inhibition (PPI) of the startle response is a measure of sensorimotor gating, a process that filters out extraneous sensory, motor and cognitive information. Humans with neurological and psychiatric disorders, including schizophrenia, obsessive-compulsive disorder and Huntington's disease, exhibit a reduction in PPI. Habituation of the startle response is also disrupted in schizophrenic patients. In order to elucidate the genes involved in sensorimotor gating, we phenotyped 472 mice from an F(2) cross between LG/J × SM/J for PPI and genotyped these mice genome-wide using 162 single nucleotide polymorphism (SNP) markers. We used prepulse intensity levels that were 3, 6 and 12 dB above background (PPI3, PPI6 and PPI12, respectively). We identified a significant quantitative trait locus (QTL) on chromosome 12 for all three prepulse intensities as well as a significant QTL for both PPI6 and PPI12 on chromosome 11. We identified QTLs on chromosomes 7 and 17 for the startle response when sex was included as an interactive covariate and found a QTL for habituation of the startle response on chromosome 4. We also phenotyped 135 mice from an F(34) advanced intercross line (AIL) between LG/J × SM/J for PPI and genotyped them at more than 3000 SNP markers. Inclusions of data from the AIL mice reduced the size of several of these QTLs to less than 5 cM. These results will be useful for identifying genes that influence sensorimotor gaiting and show the power of AIL for fine mapping of QTLs.

Fine-mapping of muscle weight QTL in LG/J and SM/J intercrosses

Genetic variation plays a substantial role in variation in strength, but the underlying mechanisms remain poorly understood. The objective of the present study was to examine the mechanisms underlying variation in muscle mass, a predictor of strength, between LG/J and SM/J strains, which are the inbred progeny of mice selected, respectively, for high and low body weight. We measured weight of five hindlimb muscles in LG/J and SM/J males and females, in F(1) and F(2) intercrosses, and in an advanced intercross (AI), F(34), between the two. F(2) mice were genotyped using 162 SNPs throughout the genome; F(34) mice were genotyped at 3,015 SNPs. A twofold difference in muscle mass between the LG/J and SM/J mouse strains was observed. Integrated genome-wide association analysis in the combined population of F(2) and AI identified 22 quantitative trait loci (QTL; genome-wide P < 0.05) affecting muscle weight on Chr 2 (2 QTL), 4, 5, 6 (7 QTL), 7 (4 QTL), 8 (4 QTL), and 11 (3 QTL). The LG/J allele conferred greater muscle weight in all cases. The 1.5-LOD QTL support intervals ranged between 0.3 and 13.4 Mb (median 3.7 Mb) restricting the list of candidates to between 5 and 97 genes. Selection for body weight segregated the alleles affecting skeletal muscle, the most abundant tissue in the body. Combination of analyses in an F(2) and AI was an effective strategy to detect and refine the QTL in a genome-wide manner. The achieved resolution facilitates further elucidation of the underlying genetic mechanisms affecting muscle mass.

Atropine, fentanyl and succinylcholine for non-urgent intubations in newborns

OBJECTIVE

Describe intubation conditions and adverse events when using atropine fentanyl +/- succinylcholine as premedication.

DESIGN

Prospective observational study, as part of a quality improvement initiative.

SETTING

Two level 3 neonatal intensive care units in Ottawa, Canada

PATIENTS

60 infants, median 27 weeks gestation, 1023 g at birth were included.

INTERVENTIONS

Infants received atropine, fentanyl +/- succinylcholine prior to the intubation. Succinylcholine was given for all infants > or =34 weeks and at the discretion of the physician for those <34 weeks.

MAIN OUTCOME MEASURES

The primary outcome was the number of attempts. Secondary outcomes were number of attempts and intubation conditions in infants who received and those who did not receive succinylcholine and safety.

RESULTS

The median number of attempts was 2. 91.7% had excellent or good conditions. The median number of attempts for infants who received succinylcholine was lower (1 vs 2) than those who did not. No serious adverse events were noted. 2 cases of difficult bag and mask ventilation after administration of fentanyl were noted.

CONCLUSION

Atropine, fentanyl and succinylcholine before non-urgent intubations in newborns has led to a low number of attempts and good intubation conditions with no adverse events.

Genome-wide linkage scan in a large bipolar disorder sample from the National Institute of Mental Health genetics initiative suggests putative loci for bipolar disorder, psychosis, suicide, and panic disorder

We conducted a 9-cM genome scan in a large bipolar pedigree sample from the National Institute of Mental Health genetics initiative (1060 individuals from 154 multiplex families). We performed parametric and nonparametric analyses using both standard diagnostic models and comorbid conditions thought to identify phenotypic subtypes: psychosis, suicidal behavior, and panic disorder. Our strongest linkage signals (genome-wide significance) were observed on chromosomes 10q25, 10p12, 16q24, 16p13, and 16p12 using standard diagnostic models, and on 6q25 (suicidal behavior), 7q21 (panic disorder) and 16p12 (psychosis) using phenotypic subtypes. Several other regions were suggestive of linkage, including 1p13 (psychosis), 1p21 (psychosis), 1q44, 2q24 (suicidal behavior), 2p25 (psychosis), 4p16 (psychosis, suicidal behavior), 5p15, 6p25 (psychosis), 8p22 (psychosis), 8q24, 10q21, 10q25 (suicidal behavior), 10p11 (psychosis), 13q32 and 19p13 (psychosis). Over half the implicated regions were identified using phenotypic subtypes. Several regions - 1p, 1q, 6q, 8p, 13q and 16p - have been previously reported to be linked to bipolar disorder. Our results suggest that dissection of the disease phenotype can enrich the harvest of linkage signals and expedite the search for susceptibility genes. This is the first large-scale linkage scan of bipolar disorder to analyze simultaneously bipolar disorder, psychosis, suicidal behavior, and panic disorder.

Linkage analysis of psychosis in bipolar pedigrees suggests novel putative loci for bipolar disorder and shared susceptibility with schizophrenia

The low-to-moderate resolution of linkage analysis in complex traits has underscored the need to identify disease phenotypes with presumed genetic homogeneity. Bipolar disorder (BP) accompanied by psychosis (psychotic BP) may be one such phenotype. We previously reported a genome-wide screen in a large bipolar pedigree sample. In this follow-up study, we reclassified the disease phenotype based on the presence or absence of psychotic features and subgrouped pedigrees according to familial load of psychosis. Evidence for significant linkage to psychotic BP (genome-wide P<0.05) was obtained on chromosomes 9q31 (lod=3.55) and 8p21 (lod=3.46). Several other sites were supportive of linkage, including 5q33 (lod=1.78), 6q21 (lod=1.81), 8p12 (lod=2.06), 8q24 (lod=2.01), 13q32 (lod=1.96), 15q26 (lod=1.96), 17p12 (lod=2.42), 18q21 (lod=2.4), and 20q13 (lod=1.98). For most loci, the highest lod scores, including those with genome-wide significance (at 9q31 and 8p21), occurred in the subgroup of families with the largest concentration of psychotic individuals (> or =3 in a family). Interestingly, all regions but six--5q33, 6q21, 8p21, 8q24, 13q32 and 18q21--appear to be novel; namely, they did not show notable linkage to BP in other genome scans, which did not employ psychosis for disease classification. Also of interest is possible overlap with schizophrenia, another major psychotic disorder: seven of the regions presumed linked in this study--5q, 6q, 8p, 13q, 15q, 17p, and 18q--are also implicated in schizophrenia, as are 2p13 and 10q26, which showed more modest support for linkage. Our results suggest that BP in conjunction with psychosis is a potentially useful phenotype that may: (1) expedite the detection of susceptibility loci for BP and (2) cast light on the genetic relationship between BP and schizophrenia.

[Observation of apoptosis and proliferation in nasopharyngeal carcinoma]

In order to observe the apoptosis and proliferation of cells in nasopharyngeal carcinoma(NPC) and pericarcinomatous tissue(PCT), 49 cases of NPC and partly PCT were detected by in situ end-labelling (ISEL) technique and proliferating cell nuclear antigen(PCNA) immunohistochemical staining. The results showed that: 1. Massive distribution of ISEL positive cells was frequently exhibited in vesicular nucleus cell carcinoma(VNCC) of NPC, in which no apoptotic pattern character was found. 2. The positive rate and the staining intensity index(SII) of ISEL signals in NPC were higher than that in PCT(P < 0.05); the positive correlation between ISEL SII and PCNA SII was found in NPC(r = 0.341, P < 0.05), whereas the positive rate and the SII of ISEL signals were significantly lower than that of PCNA (P < 0.01). 3. The ISEL SII and the PCNA SII in VNCC were obviously higher than that in poorly differentiated squamous cell carcinoma(PDSCC) (P < 0.01, P < 0.05). Patients with VNCC had a high five-year survival rate. The results suggest that there is a relationship between cellular proliferation and cellular apoptosis in NPC.

[Regulation of p53 and bcl-2 proteins to apoptosis and cell proliferation in liver cirrhosis and hepatocellular carcinoma]

In situ apoptosis labelling was used for detecting apoptotic cells, and immunohistochemistry for p53, bcl-2 proteins and proliferation cell nuclear antigen(PCNA) in hepatocellular carcinoma(HCC) and liver cirrhosis tissues. The results were that in HCC, the number of apoptotic cells was higher, the density of proliferation cells lower, and expressions of p53 and bcl-2 protein were stronger than that in liver cirrhosis, and they were related to differentiation degree of HCC. The data indicate that overexpression of bcl-2 and mutant p53 proteins, which causes imbalance between cell proliferation and apoptosis, may bring about genesis and development of HCC by selecting proliferation of cells.

Comparison of marker intervals and number of sib pairs used for linkage analysis on simulated nuclear family data

Using a two-stage global scan design, we analyzed general population replicates 1 and 42 of the Genetic Analysis Workshop (GAW) 12 simulated data set using three methods: revisited Haseman-Elston (HER), maximum likelihood variance estimation (ML), and variance components (VC). Three marker densities, 5-, 10-, and 15-cM intervals, were examined in the first-stage scan. We found that the 10-cM interval appears to be the most cost-effective approach in genotyping without sacrificing power when using a first stage significance level of 0.01. Subsequently, we performed the second-stage scan at 1-cM intervals for those putative positive regions identified in the first-stage scan at a significance level of 0.01. We also compared the power to detect linkage using different numbers of sib pairs for a genome-wide scan at a 10-cM interval and found that power decreases nonlinearly as the number of sib pairs decreases.

[Effect of hepatitis C virus nonstructural protein NS3 on telomerase activity]

OBJECTIVE

To study the effect of hepatitis C virus nonstructural protein NS3 (HCV NS3) on telomerase activity and its carcinogenesis, and to observe the practical use of in situ telomerase activity labeling.

METHODS

NIH3T3 cells were transfected with plasmid pRcHCNS3-5prime prime or minute (expressing HCV NS3 C-terminal deleted protein), pRcHCNS3-3prime prime or minute (expressing HCV NS3 N-terminal deleted protein) and blank plasmid pRcCMV. Positive clones, 11 with plasmid pRcHCNS3-5prime prime or minute, 11 with pRcHCNS3-3prime prime or minute and 8 with plasmid pRcCMV were harvested respectively. Streptavidin-peroxidase conjugated method (SP) was used to detect the expression of HCV NS3 protein in NIH3T3 cells transfected with plasmid pRcHCNS3-5prime prime or minute and pRcHCNS3-3prime prime or minute. Telomerase activity was detected by in situ telomerase activity labeling method and telomerase PCR ELISA technique in the transfected and non-transfected NIH3T3 cells.

RESULTS

HCV NS3 protein was expressed in the cells transfected with plasmid pRcHCNS3-5prime prime or minute or plasmid pRcHCNS3-3prime prime or minute. The positive signals of HCV NS3 protein were localized in the cytoplasm of transfected NIH3T3 cells, and the signal intensity of the former was stronger (chi(2) = 6.667 P < 0.05). There was significant difference on telomerase activity between each group (F = 134.083 P < 0.01). Telomerase activity in all 11 clones with plasmid pRcHCNS3-5prime prime or minute was stronger than cells with plasmid pRcHCNS3-3prime prime or minute (P < 0.01), whereas telomerase activity in NIH3T3 cells transfected with the plasmid pRcCMV or non-transfected NIH3T3 cells were weaker than the cells with the plasmid pRcHCNS3-3prime prime or minute. The expression level of HCV NS3 protein were correlated significantly with the strength of telomerase activity (rs = 0.8084 P < 0.01). The results obtained with in situ telomerase activity labeling corresponded to those with telomerase PCR ELISA technique (rs = 0.50196 P < 0.01).

CONCLUSIONS

(1) HCV NS3 protein may activate telomerase through endogenous mechanism to induce host cells transformation. (2) The effect of HCV NS3 C-terminal deleted protein on telomerase activity in host cells may be more intense than that of HCV NS3 N-terminal deleted protein. (3) In situ telomerase activity labeling is a reliable technique for studying pathological morphology and telomerase activity in tissues and cells.

Discovery and mapping of ten novel G protein-coupled receptor genes

We report the identification, cloning and tissue distributions of ten novel human genes encoding G protein-coupled receptors (GPCRs) GPR78, GPR80, GPR81, GPR82, GPR93, GPR94, GPR95, GPR101, GPR102, GPR103 and a pseudogene, psi GPR79. Each novel orphan GPCR (oGPCR) gene was discovered using customized searches of the GenBank high-throughput genomic sequences database with previously known GPCR-encoding sequences. The expressed genes can now be used in assays to determine endogenous and pharmacological ligands. GPR78 shared highest identity with the oGPCR gene GPR26 (56% identity in the transmembrane (TM) regions). psi GPR79 shared highest sequence identity with the P2Y(2) gene and contained a frame-shift truncating the encoded receptor in TM5, demonstrating a pseudogene. GPR80 shared highest identity with the P2Y(1) gene (45% in the TM regions), while GPR81, GPR82 and GPR93 shared TM identities with the oGPCR genes HM74 (70%), GPR17 (30%) and P2Y(5) (40%), respectively. Two other novel GPCR genes, GPR94 and GPR95, encoded a subfamily with the genes encoding the UDP-glucose and P2Y(12) receptors (sharing >50% identities in the TM regions). GPR101 demonstrated only distant identities with other GPCR genes and GPR102 shared identities with GPR57, GPR58 and PNR (35-42% in the TM regions). GPR103 shared identities with the neuropeptide FF 2, neuropeptide Y2 and galanin GalR1 receptors (34-38% in the TM regions). Northern analyses revealed GPR78 mRNA expression in the pituitary and placenta and GPR81 expression in the pituitary. A search of the GenBank databases with the GPR82 sequence retrieved an identical sequence in an expressed sequence tag (EST) partially encoding GPR82 from human colonic tissue. The GPR93 sequence retrieved an identical, human EST sequence from human primary tonsil B-cells and an EST partially encoding mouse GPR93 from small intestinal tissue. GPR94 was expressed in the frontal cortex, caudate putamen and thalamus of brain while GPR95 was expressed in the human prostate and rat stomach and fetal tissues. GPR101 revealed mRNA transcripts in caudate putamen and hypothalamus. GPR103 mRNA signals were detected in the cortex, pituitary, thalamus, hypothalamus, basal forebrain, midbrain and pons.

Similarity of the yellow chromophores isolated from human cataracts with those from ascorbic acid-modified calf lens proteins: evidence for ascorbic acid glycation during cataract formation

Chromatographic evidence supporting the similarity of the yellow chromophores isolated from aged human and brunescent cataract lenses and calf lens proteins ascorbylated in vitro is presented. The water-insoluble fraction from early stage brunescent cataract lenses was solubilized by sonication (WISS) and digested with a battery of proteolytic enzymes under argon to prevent oxidation. Also, calf lens proteins were incubated with ascorbic acid for 4 weeks in air and submitted to the same digestion. The percent hydrolysis of the proteins to amino acids was approximately 90% in every case. The content of yellow chromophores was 90, 130 and 250 A(330) units/g protein for normal human WISS, cataract WISS and ascorbate-modified bovine lens proteins respectively. Aliquots equivalent to 2.0 g of digested protein were subjected to size-exclusion chromatography on a Bio-Gel P-2 column. Six peaks were obtained for both preparations and pooled. Side by side thin-layer chromatography (TLC) of each peak showed very similar R(f) values for the long wavelength-absorbing fluorophores. Glycation with [U-(14)C]ascorbic acid, followed by digestion and Bio-Gel P-2 chromatography, showed that the incorporated radioactivity co-eluted with the A(330)-absorbing peaks, and that most of the fluorescent bands were labeled after TLC. Peaks 2 and 3 from the P-2 were further fractionated by preparative Prodigy C-18 reversed-phase high-performance liquid chromatography. Two major A(330)-absorbing peaks were seen in peak 2 isolated from human cataract lenses and 5 peaks in fraction 3, all of which eluted at the same retention times as those from ascorbic acid glycated calf lens proteins. HPLC fractionation of P-2 peaks 4, 5 and 6 showed many A(330)-absorbing peaks from the cataract WISS, only some of which were identical to the asorbylated proteins. The major fluorophores, however, were present in both preparations. These data provide new evidence to support the hypothesis that the yellow chromophores in brunescent lenses represent advanced glycation endproducts (AGEs) probably due to ascorbic acid glycation in vivo.

Suppression of platelet-type 12-lipoxygenase activity in human erythroleukemia cells by an RNA-cleaving DNAzyme

Human platelet-type 12-lipoxygenase (12-LOX) and its metabolites play a crucial role in tumor angiogenesis. A "10-23" deoxyribozyme (DNAzyme) and its phosphorothioate-modified version were designed and synthesized against the 12-LOX mRNA. Both DNAzymes were able to cleave their substrate efficiently in a time- and concentration-dependent manner in vitro. Under a multiple turnover condition, both performed well at 37 degrees C, showing the k(cat) of 1 and 0.26 min(-1), respectively. The phosphorothioate modification of the DNAzyme significantly increased its stability in cells without a substantial loss of kinetic efficiency in vitro. In a cell culture system, transfection of the DNAzymes into HEL cells resulted in a significant down-regulation of the 12-LOX mRNA. Furthermore, the cell extracts from the DNAzyme-transfected cells exhibited a marked reduction in the 12-LOX enzyme activity. The present results indicated the potential use of DNAzyme technology for gene function study and cancer therapy.

Discovery of a novel member of the histamine receptor family

We report the discovery, tissue distribution and pharmacological characterization of a novel receptor, which we have named H4. Like the three histamine receptors reported previously (H1, H2, and H3), the H4 receptor is a G protein-coupled receptor and is most closely related to the H3 receptor, sharing 58% identity in the transmembrane regions. The gene encoding the H4 receptor was discovered initially in a search of the GenBank databases as sequence fragments retrieved in a partially sequenced human genomic contig mapped to chromosome 18. These sequences were used to retrieve a partial cDNA clone and, in combination with genomic fragments, were used to determine the full-length open reading frame of 390 amino acids. Northern analysis revealed a 3.0-kb transcript in rat testis and intestine. Radioligand binding studies indicated that the H4 receptor has a unique pharmacology and binds [(3)H]histamine (K(d) = 44 nM) and [(3)H]pyrilamine (K(d) = 32 nM) and several psychoactive compounds (amitriptyline, chlorpromazine, cyproheptadine, mianserin) with moderate affinity (K(i) range of 33-750 nM). Additionally, histamine induced a rapid internalization of HA-tagged H4 receptors in transfected human embryonic kidney 293 cells.

Identification of four novel human G protein-coupled receptors expressed in the brain

We report the discovery and tissue distributions of four novel human genes, GPR61, GPR62, GPR63 and GPR77, all of which encode G protein-coupled receptors (GPCRs). GPR61 was discovered in a search of the patent literature which retrieved a rabbit DNA sequence partially encoding a novel GPCR. This sequence was used to obtain a full-length human cDNA encoding GPR61, a receptor of 417 amino acid length. A search of the GenBank genomic sequence databases revealed three previously unrecognized intronless genes encoding the orphan GPCrs (oGPCRs) GPR62, GPR63 and GPR77, with respective amino acid lengths of 368, 419 and 337. Sequence analysis revealed that GPR61 and GPR62, and a published orphan receptor p47MNR, shared the highest level of identities to each other, ranging from 36 to 45% in the transmembrane (TM) domains. Together, these three oGPCRs appear to comprise a novel subfamily of GPCRs, most closely related to the serotonin 5-HT(6) receptor. Sequence analysis of GPR63 and GPR77 revealed highest sequence identities in the TM regions with the oGPCR PSP24 (58%) and the anaphylatoxin C5a receptor (49%) respectively. Tissue distribution analyses detected the expression of all four novel genes in the human brain. GPR61 mRNA expression was detected in the caudate, putamen and thalamus of human brain, with a more widespread expression pattern in rat brain, with mRNA signals in areas of the cortex, hippocampus, thalamus, hypothalamus and midbrain. GPR62 mRNA expression was detected in the basal forebrain, frontal cortex, caudate, putamen, thalamus and hippocampus. GPR63 mRNA expression was detected in the frontal cortex, with lower levels in the thalamus, caudate, hypothalamus and midbrain. Analysis of GPR77 mRNA expression revealed signals in the frontal cortex, hippocampus and hypothalamus with high transcript levels in the liver.

Genetic crossover interference in the human genome

Positive crossover interference refers to the phenomenon that the occurrence of a crossover reduces the probability of another crossover in its vicinity. There have been studies reporting the presence of positive interference in humans. Some studies have also found evidence suggesting within and between chromosomal interference heterogeneity on some of the chromosomes. However, there has been no systematic study of interference and interference heterogeneity in the whole human genome, using pedigree data without first inferring crossovers. In this paper, we studied the Chi-square interference model and other models extensively to compare the relative performance of each of these models for accounting for interference and measuring strength of interference. Our results showed that the Chi-square model consistently fitted the data well and provided easily interpretable estimates of interference strength. The Chi-square model was then used to study interference and interference heterogeneity within and between chromosomes. We found strong evidence of positive interference in the whole human genome. Our results also indicated that the level of interference was fairly constant in most parts of the genome, but there was some evidence suggesting that the levels of interference for two of the chromosomes were different from the rest. We also found evidence of within chromosomal interference heterogeneity for several of the chromosomes.

Characterization of the human cysteinyl leukotriene 2 receptor

The contractile and inflammatory actions of the cysteinyl leukotrienes (CysLTs), LTC(4), LTD(4), and LTE(4), are thought to be mediated through at least two distinct but related CysLT G protein-coupled receptors. The human CysLT(1) receptor has been recently cloned and characterized. We describe here the cloning and characterization of the second cysteinyl leukotriene receptor, CysLT(2), a 346-amino acid protein with 38% amino acid identity to the CysLT(1) receptor. The recombinant human CysLT(2) receptor was expressed in Xenopus oocytes and HEK293T cells and shown to couple to elevation of intracellular calcium when activated by LTC(4), LTD(4), or LTE(4). Analyses of radiolabeled LTD(4) binding to the recombinant CysLT(2) receptor demonstrated high affinity binding and a rank order of potency for competition of LTC(4) = LTD(4) LTE(4). In contrast to the dual CysLT(1)/CysLT(2) antagonist, BAY u9773, the CysLT(1) receptor-selective antagonists MK-571, montelukast (Singulair(TM)), zafirlukast (Accolate(TM)), and pranlukast (Onon(TM)) exhibited low potency in competition for LTD(4) binding and as antagonists of CysLT(2) receptor signaling. CysLT(2) receptor mRNA was detected in lung macrophages and airway smooth muscle, cardiac Purkinje cells, adrenal medulla cells, peripheral blood leukocytes, and brain, and the receptor gene was mapped to chromosome 13q14, a region linked to atopic asthma.