Cranial synchondroses of primates at birth.

Cranial synchondroses are cartilaginous joints between basicranial bones or between basicranial bones and septal cartilage, and have been implicated as having a potential active role in determining craniofacial form. However, few studies have examined them histologically. Using histological and immunohistochemical methods, we examined all basicranial joints in serial sagittal sections of newborn heads from nine genera of primates (five anthropoids, four strepsirrhines). Each synchondrosis was examined for characteristics of active growth centers, including a zonal distribution of proliferating and hypertrophic chondrocytes, as well as corresponding changes in matrix characteristics (i.e., density and organization of Type II collagen). Results reveal three midline and three bilateral synchondroses possess attributes of active growth centers in all species (sphenooccipital, intrasphenoidal, presphenoseptal). One midline synchondrosis (ethmoseptal) and one bilateral synchondrosis (alibasisphenoidal synchondrosis [ABS]) are active growth centers in some but not all newborn primates. ABS is oriented more anteriorly in monkeys compared to lemurs and bushbabies. The sphenoethmoidal synchondrosis (SES) varies at birth: in monkeys, it is a suture-like joint (i.e., fibrous tissue between the two bones); however, in strepsirrhines, the jugum sphenoidale is ossified while the mesethmoid remains cartilaginous. No species possesses an SES that has the organization of a growth plate. Overall, our findings demonstrate that only four midline synchondroses have the potential to actively affect basicranial angularity and facial orientation during the perinatal timeframe, while the SES of anthropoids essentially transitions toward a "suture-like" function, permitting passive growth postnatally. Loss of cartilaginous continuity at SES and reorientation of ABS distinguish monkeys from strepsirrhines.

Linkage and association with the NOS2A locus on chromosome 17q11 in multiple sclerosis.

A large body of research supports a multifactorial cause in multiple sclerosis (MS), with an underlying genetic susceptibility likely acting in concert with undefined environmental exposures. Here, we used a highly efficient multilocus genotyping assay to study single nucleotide polymorphisms representing variation in 34 genes from inflammatory pathways in a well-characterized MS familial data set. Evidence of transmission distortion was present for several polymorphisms. Results for the NOS2A locus (exon 10 C/T, D346D) on chromosome 17q11 remained significant after correction for multiple testing and were reproduced in a second independent African American MS data set. In addition, linkage to a NOS2A promoter region polymorphism, (CCTTT)(n), was present in a third data set of multicase MS families. Our results provide strong evidence for linkage and association to a new candidate disease gene on chromosome 17q11 in MS and suggest that variation within NOS2A or a nearby locus contributes to disease susceptibility.

Prognostic markers of radiographic progression in early rheumatoid arthritis.

OBJECTIVE: To identify prognostic markers that are predictive of progressive erosive disease in patients with early rheumatoid arthritis (RA). METHODS: The study involved an inception cohort of 111 consecutive patients with RA and a disease duration of <1 year. Patients were treated according to an algorithm designed to avoid overtreatment of mild disease and to accelerate treatment in patients who had continuous disease activity. Patients were evaluated for the presence of clinical and laboratory disease activity markers. We determined the frequency of CD4+,CD28(null) T cells by flow cytometry, HLA-DRB1 gene polymorphisms by polymerase chain reaction (PCR)/sequencing, and 26 single-nucleotide polymorphisms in 19 candidate genes by multiplex PCR and hybridization to an immobilized probe array. Data were analyzed using proportional odds models to identify prognostic markers predictive of erosive progression over 2 years on serial hand/wrist radiographs. RESULTS: After 2 years, disease activity in 52% of the cohort was controlled by treatment with hydroxychloroquine and nonsteroidal agents. Forty-eight percent of the patients did not develop erosions. Older age, presence of erosions at baseline, presence of rheumatoid factor, rheumatoid factor titer, and HLA-DRB1*04 alleles, particularly homozygosity for HLA-DRB1*04, were univariate predictors of radiographic progression. Promising novel markers were the frequency of CD4+,CD28(null) T cells as an immunosenescence indicator, and a polymorphism in the uteroglobin gene. CONCLUSION: Clinical disease activity in patients with early RA can frequently be controlled with nonaggressive treatment, but this is not always sufficient to prevent new erosions. Rheumatoid factor titer, HLA-DRB1 polymorphisms, age, and immunosenescence markers are predictors of poor radiographic outcome. A polymorphism in the uteroglobin gene may identify patients who have a low risk of erosive disease.

Identification of human remains by immobilized sequence-specific oligonucleotide probe analysis of mtDNA hypervariable regions I and II.

AIM: A rapid analysis of mitochondrial DNA (mtDNA) sequences with an array of immobilized sequence-specific oligonucleotide (SSO) probes was tested on 18 skeletal elements recovered from mass graves in Croatia, which could not be genotyped with common forensic nuclear DNA systems (PM+DQA1 and short tandem repeat analysis). METHODS: We used duplex polymerase chain reaction (PCR) amplification of the mtDNA hypervariable regions I and II (HVI and HVII) (444 bp and 415 bp amplicons, respectively) and subsequent linear array typing, which targets six polymorphic regions and two additional sites within the human mtDNA HVI and HVII. The remaining amplified products were subjected to direct sequence analysis to obtain complete sequence information for the targeted HV regions. RESULT: Duplex PCR amplification of the mtDNA HVI and HVII was successful in providing sufficient product for typing with the array of SSO probes in 14 out of the 18 sample extracts. We report here the sequence match of one set of remains with a panel of immobilized SSO probes, followed by direct sequence analysis. The corresponding mtDNA haplotype obtained for the bone sample and the putative maternal reference was unique in a database of 105 randomly selected Croatian individuals. CONCLUSION: Mitochondrial DNA typing with an array of immobilized SSO probes can be a benefit to forensic DNA analysis of mass disaster remains and identity testing of single and mass graves.

Association of IL4R haplotypes with type 1 diabetes.

We have investigated, in 282 multiplex Caucasian families (the Human Biological Data Interchange Repository), the association of type 1 diabetes with polymorphisms in the IL4R gene. IL4R encodes a subunit of the interleukin-4 receptor, a molecule critical to T-helper cell development. By genotyping eight different IL4R single-nucleotide polymorphisms (SNPs) and identifying haplotypes (complex alleles) in the multiplex type 1 diabetic families who were stratified for HLA genotype, we have observed significant evidence of linkage and association of the IL4R gene to type 1 diabetes. In particular, we have identified a specific haplotype that appears to be protective and observed that this protective effect is strongest among individuals not carrying the HLA DR3/DR4 genotype (which confers the strongest genetic risk for type 1 diabetes). These findings suggest an important role for the IL4R gene in immune-related disease susceptibility and illustrate the value of using multi-SNP haplotype information in association studies.