Identification of the breast cancer susceptibility gene BRCA2

In Western Europe and the United States approximately 1 in 12 women develop breast cancer. A small proportion of breast cancer cases, in particular those arising at a young age, are attributable to a highly penetrant, autosomal dominant predisposition to the disease. The breast cancer susceptibility gene, BRCA2, was recently localized to chromosome 13q12-q13. Here we report the identification of a gene in which we have detected six different germline mutations in breast cancer families that are likely to be due to BRCA2. Each mutation causes serious disruption to the open reading frame of the transcriptional unit. The results indicate that this is the BRCA2 gene.

Localization of a breast cancer susceptibility gene, BRCA2, to chromosome 13q12-13

A small proportion of breast cancer, in particular those cases arising at a young age, is due to the inheritance of dominant susceptibility genes conferring a high risk of the disease. A genomic linkage search was performed with 15 high-risk breast cancer families that were unlinked to the BRCA1 locus on chromosome 17q21. This analysis localized a second breast cancer susceptibility locus, BRCA2, to a 6-centimorgan interval on chromosome 13q12-13. Preliminary evidence suggests that BRCA2 confers a high risk of breast cancer but, unlike BRCA1, does not confer a substantially elevated risk of ovarian cancer.

Prevalence of BRCA1 and BRCA2 gene mutations in patients with early-onset breast cancer

BACKGROUND

Mutations in the BRCA1 and BRCA2 genes are found in most families with cases of both breast and ovarian cancer or with many cases of early-onset breast cancer. However, in an outbred population, the prevalence of BRCA1 and BRCA2 mutations in patients with breast cancer who were unselected for a family history of this disease has not been determined.

METHODS

Mutations in the BRCA1 and BRCA2 genes were detected in blood samples from two population-based series of young patients with breast cancer from Britain.

RESULTS

Mutations were detected in 15 (5.9%) of 254 women diagnosed with breast cancer before age 36 years (nine [3.5%] in BRCA1 and six [2.4%] in BRCA2) and in 15 (4.1%) of 363 women diagnosed from ages 36 through 45 years (seven [1.9%] in BRCA1 and eight [2.2%] in BRCA2). Eleven percent (six of 55) of patients with a first-degree relative who developed ovarian cancer or breast cancer by age 60 years were mutation carriers, compared with 45% (five of 11) of patients with two or more affected first- or second-degree relatives. The standardized incidence ratio for breast cancer in mothers and sisters was 365 (five observed and 1.37 expected) for 30 mutation carriers and 199 (64 observed and 32.13 expected) for 587 noncarriers. If we assume recent penetrance estimates, the respective proportions of BRCA1 and BRCA2 mutation carriers are 3.1% and 3.0%, respectively, of patients with breast cancer who are younger than age 50 years, 0.49% and 0.84% of patients with breast cancer who are age 50 years or older, and 0.11% and 0.12% of women in the general population.

CONCLUSIONS

Mutations in the BRCA1 and BRCA2 genes make approximately equal contributions to early-onset breast cancer in Britain and account for a small proportion of the familial risk of breast cancer.

Instability of short tandem repeats (microsatellites) in human cancers

The allele sizes of polymorphic microsatellite repeats in DNA from human cancers were compared to normal DNA from the same patients. In 16 out of 196 paired samples (8%), we found evidence of an extra allele of a different size in the tumour which was not present in the normal DNA. Sequence analysis confirmed that the extra allele originates from the appropriate locus and that the size change is attributable to alteration in the number of repeat units. This form of instability was more common in tri- and tetranucleotide repeats than in dinucleotide repeats. In any single tumour sample only one repeat in the set examined was abnormal, the remainder showing identical patterns in normal and tumour DNA or evidence of allele loss. The pattern of instability in diverse types of cancer differs from that reported in colorectal neoplasms.

An ACF1-ISWI chromatin-remodeling complex is required for DNA replication through heterochromatin

The mechanism by which the eukaryotic DNA-replication machinery penetrates condensed chromatin structures to replicate the underlying DNA is poorly understood. Here we provide evidence that an ACF1-ISWI chromatin-remodeling complex is required for replication through heterochromatin in mammalian cells. ACF1 (ATP-utilizing chromatin assembly and remodeling factor 1) and an ISWI isoform, SNF2H (sucrose nonfermenting-2 homolog), become specifically enriched in replicating pericentromeric heterochromatin. RNAi-mediated depletion of ACF1 specifically impairs the replication of pericentromeric heterochromatin. Accordingly, depletion of ACF1 causes a delay in cell-cycle progression through the late stages of S phase. In vivo depletion of SNF2H slows the progression of DNA replication throughout S phase, indicating a functional overlap with ACF1. Decondensing the heterochromatin with 5-aza-2-deoxycytidine reverses the effects of ACF1 and SNF2H depletion. Expression of an ACF1 mutant that cannot interact with SNF2H also interferes with replication of condensed chromatin. Our data suggest that an ACF1-SNF2H complex is part of a dedicated mechanism that enables DNA replication through highly condensed regions of chromatin.

BRCA2 mutations in primary breast and ovarian cancers

The second hereditary breast cancer gene, BRCA2, was recently isolated. Germline mutations of this gene predispose carriers to breast cancer, and, to a lesser extent, ovarian cancer. Loss of heterozygosity (LOH) at the BRCA2 locus has been observed in 30-40% of sporadic breast and ovarian tumours, implying that BRCA2 may act as a tumour suppressor gene in a proportion of sporadic cases. To define the role of BRCA2 in sporadic breast and ovarian cancer, we screened the entire gene for mutations using a combination of techniques in 70 primary breast carcinomas and in 55 primary epithelial ovarian carcinomas. Our analysis revealed alterations in 2/70 breast tumours and none of the ovarian carcinomas. One alteration found in the breast cancers was a 2-basepair (bp) deletion (4710delAG) which was subsequently shown to be a germline mutation, the other was a somatic missense mutation (Asp3095Glu) of unknown significance. Our results suggest that BRCA2 is a very infrequent target for somatic inactivation in breast and ovarian carcinomas, similar to the results obtained for BRCA1.

Molecular biology and pharmacology of cloned opioid receptors

The cloning and expression of DNA for the three major opioid receptor types (mu, delta, and kappa) present new research opportunities for the characterization of opioid drugs and their interactions with these receptors. Genomic and cDNA clones for opioid receptors exist for several animal species including mouse, rat, guinea pig, and human. These include clones for all three human opioid receptor types. The receptor proteins consist of about 400 amino acids and have the characteristic seven transmembrane domain structure of G-protein-coupled receptors. There is about 60% amino acid identity between opioid receptor types and about 90% identity between a receptor type cloned from different animal species. All opioid receptor types mediate the inhibition of adenylyl cyclase in response to agonist binding. Radioligand binding and functional studies using the cloned receptors tend to support current conclusions on opioid drug receptor selectivity and activity. Investigations of opioid receptor chimeras and single amino acid mutants are providing information on the ligand recognition sites of these receptors and essential support for the development of computational opioid receptor models. A molecular model of the human delta opioid receptor is included in this review.

Molecular characterization of the maize Rp1-D rust resistance haplotype and its mutants

The Rp1-D gene for resistance to maize common rust (Puccinia sorghi) is a member of a complex locus (haplotype) composed of Rp1-D and approximately eight other gene homologs. The identity of Rp1-D was demonstrated by using two independent gene-tagging approaches with the transposons Mutator and Dissociation. PIC20, a disease resistance (R) gene analog probe previously mapped to the rp1 locus, detected insertion of Dissociation in an Rp1-D mutation and excision in three revertants. Independent libraries probed with the PIC20 or Mutator probes resulted in isolation of the same gene sequence. Rp1-D belongs to the nucleotide binding site, leucine-rich repeat class of R genes. However, unlike the rust resistance genes M and L6 from flax, the maize Rp1-D gene does not encode an N-terminal domain with similarity to the signal transduction domains of the Drosophila Toll protein and mammalian interleukin-1 receptor. Although the abundance of transcripts of genes from the rp1 complex changed with leaf age, there was no evidence of any change due to inoculation with avirulent or virulent rust biotypes. A set of 27 Rp1-D mutants displayed at least nine different deletions of Rp1-D gene family members that were consistent with unequal crossing-over events. One mutation (Rp1-D*-24) resulted in deletion of all but one gene family member. Other unique deletions were observed in the disease lesion mimic Rp1-D*-21 and the partially susceptible mutant Rp1-D*-5. Different rp1 specificities have distinct DNA fingerprints (haplotypes). Analysis of recombinants between rp1 specificities indicated that recombination had occurred within the rp1 gene complex. Similar analyses indicated that the rust R genes at the rp5 locus, 2 centimorgans distal to rp1, are not closely related to Rp1-D.

Prenatal health behaviors and psychosocial risk factors in pregnant women of Mexican origin: the role of acculturation

OBJECTIVES

This study examined the association between acculturation of Mexican-origin women and factors in low birthweight and preterm delivery.

METHODS

Interviews were conducted with 911 Mexican-origin respondents in Los Angeles prenatal care clinics. Infant outcome data were retrieved from delivery records.

RESULTS

Mexican-American women had generally more undesirable prenatal behaviors and risk factors than Mexican-immigrant women. Although higher acculturation was significantly associated with behavioral risk factors, there were no direct effects of acculturation on infant gestational age or birthweight.

CONCLUSIONS

Future research needs to measure multiple factors to assess their effects on culture-specific protective factors.

Atypical ductal hyperplasia of the breast: clonal proliferation with loss of heterozygosity on chromosomes 16q and 17p

AIMS

To determine if allelic loss on chromosomes 16q and 17p, commonly encountered in in situ and invasive ductal carcinomas, is present in atypical ductal hyperplasia (ADH); to determine whether ADH is a neoplastic (clonal) or hyperplastic (polyclonal) proliferation.

METHODS

Fourteen cases of ADH were examined for allele loss at loci on chromosome 16q and 17p using a microdissection technique, polymorphic DNA markers and the polymerase chain reaction (PCR).

RESULTS

Loss of heterozygosity (LOH) was detected in five of nine informative cases on chromosome 16q at the microsatellite D16S413 and two of eight informative cases on chromosome 17p at D17S796.

CONCLUSIONS

The incidence of LOH at these loci is similar to that previously observed in ductal carcinoma in situ and in invasive ductal carcinoma. Because of the nature of the technique used, our findings also demonstrate that ADH is a monoclonal, and hence, neoplastic proliferation rather than a hyperplastic (polyclonal) condition as its name suggests. There is thus a case for including ADH, as presently defined, within the spectrum of ductal carcinoma in situ.

Genetic alterations in 'normal' luminal and myoepithelial cells of the breast

Chromosomal loci exhibiting loss of heterozygosity (LOH) at high frequency in invasive breast cancer have been investigated in 'normal' breast tissue from patients with carcinoma and from reduction mammoplasty specimens. Duct-lobular units dissected from paraffin-embedded tissues and 485 'normal' luminal and myoepithelial cell clones were studied. Overall, LOH was found in normal cells in 5/10 breast cancer cases and 1/3 reduction mammoplasty specimens. LOH was identified in normal cells adjacent to and distant from the tumour. In one case, all luminal and myoepithelial samples exhibited loss of the same allele on chromosome 13q. One case in which the patient had a germline truncating mutation in the BRCA1 gene exhibited LOH on 17q in 3/33 normal clones. One of these clones showed loss of wild-type allele indicating gene inactivation. This sample also had LOH at markers on chromosomes 11p and 13q. One of 93 clones from three reduction mammoplasties showed allele loss at a locus on chromosome 13q. The identification of LOH in breast lobules suggests that they may be clonal. The demonstration of genetic alteration in luminal and myoepithelial cells provides evidence for the presence of a common stem cell for the two epithelial cell types. LOH has been demonstrated in normal tissues near and away from the carcinoma, suggesting that genetic alterations are likely to be more heterogeneous and widespread than is currently envisaged, and probably occur very early in breast development. Homozygous deletion of BRCA1 per se does not appear to provide clonal advantage.

Androgen receptor polymorphisms: association with prostate cancer risk, relapse and overall survival

Several reports have suggested that one or both of the trinucleotide repeat polymorphisms in the human androgen receptor (hAR) gene, (CAG)n coding for polyglutamine and (GGC)n coding for polyglycine, may be associated with prostate cancer risk; but no study has investigated their association with disease progression. We present here a study of both hAR trinucleotide repeat polymorphisms not only as they relate to the initial diagnosis but also as they are associated with disease progression after therapy. Lymphocyte DNA samples from 178 British Caucasian prostate cancer patients and 195 control individuals were genotyped by PCR for the (CAG)n and (GGC)n polymorphisms in hAR. Univariate Cox proportional hazard analysis indicated that stage, grade and GGC repeat length were individually significant factors associated with disease-free survival (DFS) and overall survival (OS). The relative risk (RR) of relapse for men with more than 16 GGC repeats was 1.74 (95% CI 1. 08-2.79) and of dying from any cause, 1.98 (1.13-3.45). Adjusting for stage and grade, GGC effects remained but were not significant (RR(DFS)= 1.60, p = 0.052; RR(OS)= 1.65, p = 0.088). The greatest effects were in stage T1-T2 (RR(DFS)= 3.56, 95% CI 1.13-11.21) and grade 1 (RR(DFS)= 6.47, 95% CI 0.57-72.8) tumours. No differences between patient and control allele distributions were found by odds-ratio analysis, nor were trends with stage or grade evident in the proportion of short CAG alleles. Non-significant trends with stage and grade were found in the proportion of short GGC alleles. The (GGC)n polymorphism in this population is a significant predictor of disease outcome. Since the (GGC)(n) effect is strongest in early-stage tumours, this marker may help forecast aggressive behaviour and could be used to identify those patients meriting more radical treatment.

Loss of heterozygosity in ductal carcinoma in situ of the breast

Loss of heterozygosity (LOH) at loci reported to show allele loss in invasive breast cancers was examined in ductal in situ carcinomas of the breast using polymorphic short tandem repeats and the polymerase chain reaction (PCR). LOH was detected at all loci examined in at least 11 per cent of the samples examined. The proportion of cases of in situ carcinoma showing LOH at these loci was similar to that previously reported in invasive cancers. Cases of pure in situ cancer without an invasive component exhibited an overall lower frequency of allele loss. LOH at more than one locus was observed in some intraductal cancers. In a small number of cases, LOH was present in the invasive but not in the intraductal component of the tumour, suggesting that mutation at the locus concerned was associated with development of invasive behaviour.

Modulation of paclitaxel resistance by annexin IV in human cancer cell lines

A recurring problem with cancer therapies is the development of drug resistance. While investigating the protein profile of cells resistant to a novel antimitotic compound (A204197), we discovered an increase in annexin IV expression. When we examined the annexin IV protein expression level in a paclitaxel-resistant cell line (H460/T800), we found that annexin IV was also overexpressed. Interestingly a closely related protein, annexin II, was not overexpressed in H460/T800 cells. Immunostaining with either annexin II or IV antibody revealed that annexin IV was primarily located in the nucleus of paclitaxel-resistant H460/T800 cells. Short-term treatment of H460 cells with 10 nM paclitaxel for up to 4 days resulted in induction of annexin IV, but not annexin II expression. In addition, there was an increase in annexin IV staining in the nucleus starting at day 1. Furthermore, cells pretreated with 10 nM paclitaxel for 4 days resulted in cells becoming approximately fivefold more resistant to paclitaxel. Transfection of annexin IV cDNA into 293T cells revealed that there was a threefold increase in paclitaxel resistance. Thus our results indicate that annexin IV plays a role in paclitaxel resistance in this cell line and it is among one of the earliest proteins that is induced in cells in response to cytotoxic stress such as antimitotic drug treatment.

Loss of heterozygosity in sporadic breast tumours at the BRCA2 locus on chromosome 13q12-q13

Loss of heterozygosity (LOH) on chromosome 13 occurs on 25-30% of breast tumours. This may reflect the inactivation of the retinoblastoma susceptibility gene RB1. However, recently another candidate tumour-suppressor gene has been identified on chromosome 13 by linkage analysis, the breast cancer susceptibility gene BRCA2. To investigate the involvement of BRCA2 in sporadic breast cancer 200 breast tumours were tested for LOH on chromosome band 13q12-q14, using 11 highly polymorphic microsatellite markers. LOH was found in 65 tumours, which all showed simultaneously loss of BRCA2 and RB1. Of 12 breast tumour cell lines tested with polymorphic microsatellite markers, seven showed a contiguous region of homozygosity on 13q12-q14, suggesting LOH in the tumour from which the cell line had been derived. One cell line showed homozygosity in the BRCA2 region and heterozygosity at RB1. This is the only indication that BRCA2 is a distinct target for LOH on chromosome 13 in addition to RB1.

Loss of heterozygosity in lobular carcinoma in situ of the breast

Aims-(1) To investigate whether loss of heterozygosity identified at various loci in invasive breast carcinoma or is present in lobular carcinoma in situ (LCIS). (2) To investigate whether LCIS is a monoclonal (neoplastic) or a polyclonal (hyperplastic) proliferation.Methods-Forty three cases of LCIS (30 with associated invasive carcinoma or in situ ductal carcinoma (DCIS) and 13 cases of pure LCIS) were investigated for loss of heterozygosity on chromosomes 16q, 17q, 17p, and 13q using a microdissection technique, polymorphic DNA markers, and the polymerase chain reaction (PCR).Results-Loss of heterozygosity was detected in both subgroups of LCIS at all the loci examined. There was no significant difference in the frequency of the loss between the group associated with invasive carcinoma and the pure LCIS group. The frequency of loss of heterozygosity ranged from 8% on 17p to 50% on 17q.Conclusions-Because of the nature of the technique employed, our findings show that LCIS is a monoclonal (neoplastic) proliferation rather than a hyperplastic proliferation. The incidence of loss of heterozygosity on 17p (D17S796) is lower than we have observed previously in DCIS, suggesting that LCIS and DCIS are different genetically as well as clinically and morphologically. The similar incidence of loss of heterozygosity on 16q and 17q, however, suggests that DCIS and LCIS may share a common pathway of evolution.

Absence of methylation of CpG dinucleotides within the promoter of the breast cancer susceptibility gene BRCA2 in normal tissues and in breast and ovarian cancers

Germline mutations of the BRCA2 gene on chromosome 13q12-q13 predispose to the development of early-onset breast cancer and ovarian cancer. Loss of heterozygosity detected using chromosome 13q markers in the vicinity of BRCA2 is observed in most cancers arising in carriers of germline BRCA2 mutations and also in 30-50% of sporadic breast and ovarian cancers. However, somatic mutations of BRCA2 are extremely rare in sporadic cancers. We have examined the hypothesis that expression of the BRCA2 gene may be suppressed in sporadic breast cancers by a mechanism that is associated with increased methylation of cytosine residues in the promoter region. Using a HpaII/MspI digestion-polymerase chain reaction based assay, the presence of 5-methylcytosine in three CpG dinucleotides within the BRCA2 promoter was assessed in 18 breast or ovarian cancer cell lines, in an SV40 large T antigen immortalized cell line derived from normal breast epithelial cells, in 64 primary sporadic breast cancers and peripheral blood leucocytes from these cases and in a number of other normal human tissues. Methylation was not detected in any of the tissues examined, suggesting that this mechanism of transcriptional repression is unlikely to explain the absence of somatic mutations in sporadic cancers.

The localization of glycollate-pathway enzymes in Euglena

Isolation of organelles from broken-cell suspensions of phototrophically grown Euglena gracilis Klebs was achieved by isopycnic centrifugation on sucrose gradients. 2. Equilibrium densities of 1.23g/cm3 for peroxisome-like particles, 1.22g/cm3 for mitochondria and 1.17g/cm3 for chloroplasts were recorded. 3. The enzymes glycollate dehydrogenase, glutamate-glyoxylate aminotransferase, serineglyoxylate aminotransferase, aspartate-alpha-oxoglutarate aminotransferase, hydroxy pyruvate reductase and malate dehydrogenase were present in peroxisome-like particles. 4. Unlike higher plants glycollate dehydrogenase and glutamate-glyoxylate aminotransferase were present in the mitochondria of Euglena. 5. Rates of glycollate and D-lactate oxidation were additive in the mitochondria, and, although glycollate dehydrogenase was inhibited by cyanide, D-lactate dehydrogenase activity was unaffected. 6. Glycollate oxidation was linked to O2 uptake in mitochondria but not in peroxisome-like particles. This glycollate-dependent O2 uptake was inhibited by antimycin A or cyanide. 7. The physiological significance of glycollate metabolism in Euglena mitochondria is discussed, with special reference to its role in photorespiration in algae.

Germline mutations in BRCA1 and BRCA2 in breast-ovarian families from a breast cancer risk evaluation clinic

PURPOSE

Data from the Breast Cancer Linkage Consortium suggest that the proportion of familial breast and ovarian cancers linked to BRCA1 or BRCA2 may be as high as 98% depending on the characteristics of the families, suggesting that mutations in BRCA1 or BRCA2 may entirely account for hereditary breast and ovarian cancer families. We sought to determine what proportion of families with both breast and ovarian cancers seen in a breast cancer risk evaluation clinic are accounted for by coding region germline mutations in BRCA1 and BRCA2 as compared to a linkage study group. We also evaluated what clinical parameters were predictive of mutation status.

PATIENTS AND METHODS

Affected women from 100 families with at least one case of breast cancer and at least one case of ovarian cancer in the same lineage were screened for germline mutations in the entire coding regions of BRCA1 and BRCA2 by conformation-sensitive gel electrophoresis, a polymerase chain reaction-based heteroduplex analysis, or direct sequencing.

RESULTS

Unequivocal deleterious mutations were found in 55% (55 of 100) of the families studied. Mutations in BRCA1 and BRCA2 accounted for 80% and 20% of the mutations overall, respectively. Using multivariate analysis, the strongest predictors of detecting a mutation in BRCA1 or BRCA2 in this study group were the presence of a single family member with both breast and ovarian cancer (P <.0009; odds ratio [OR], 5.68; 95% confidence interval [CI], 2.04 to 15.76) and a young average age at breast cancer diagnosis in the family (P <.0016; OR, 1.69; 95% CI, 1.23 to 2.38).

CONCLUSION

These results suggest that at least half of breast/ovarian families evaluated in a high-risk cancer evaluation clinic may have germline mutations in BRCA1 or BRCA2. Whether the remaining families have mutations in noncoding regions in BRCA1, mutations in other, as-yet-unidentified, low-penetrance susceptibility genes, or represent chance clustering remains to be determined.

Bare lymphocyte syndrome: altered HLA class II expression in B cell lines derived from two patients

Types II and III bare lymphocyte syndrome (BLS) are severe or lethal congenital immunodeficiencies characterized by defective cell surface expression of HLA class II antigens. We have analyzed by Southern and Northern blotting B-lymphoblastoid cell lines derived by Epstein-Barr virus (EBV) transformation from peripheral blood lymphocytes of two unrelated BLS patients and their families. While DNA analyses of both families showed no indication of rearrangement or alteration of HLA region genes, class II mRNAs were virtually absent in the patients' cell lines (BLS-1 and BLS-2). This is consistent with previous observations of different BLS patients and their families. An exception to the absence of class II mRNAs in BLS was the detection of low quantities of HLA-DQ alpha transcripts in the cell lines BLS-1. This finding provides further evidence that factors regulating HLA-DQ expression may differ from those governing expression of the other class II genes.

Proton pump inhibitors: a survey of prescribing in an Irish general hospital

Prescription rates and attendant costs of proton pump inhibitors (PPIs) continue to rise. The aim of this study was to assess the extent and appropriateness of PPI prescribing in an Irish general hospital. Using a structured pro forma, we conducted a 1-day comprehensive survey of the prescription charts of all inpatients. Of the 157 inpatients, 48 (30.6%) were on PPI therapy and omeprazole was the most widely prescribed PPI. Rabeprazole, the least expensive PPI, was the least prescribed. Prescription of PPI therapy was for an approved indication in 32 patients (66.6%) but was for an unapproved or unknown indication in 16 (33.3%). Prescribing had been initiated in hospital in 34 patients (70.8%) but only one-third of the patients on PPI therapy had undergone endoscopy. Over 90% of patients were on additional, often multiple, prescribed medications. Our results suggest that PPIs are overprescribed in hospital practice, and there is scope to improve the quality and cost-effectiveness of PPI prescribing.

Treatment of equine cheek teeth by mechanical widening of diastemata in 60 horses (2000-2006)

REASON FOR PERFORMING STUDY

Cheek teeth (CT) diastemata are a significant cause of painful dental disease in horses and limited factual information is available on the treatment of this disorder.

OBJECTIVE

To assess the response to mechanical widening in the treatment of diastema.

METHOD

Details of the presenting signs and treatment of cases of CT diastema by widening were recorded and the response to treatment of these cases assessed by re-examinations and by obtaining follow-up information from owners.

RESULTS

Sixty horses of various breeds, median age 9 years, with clinically significant CT diastemata were classified as having primary (inadequate rostro-caudal CT compression: n = 29) and secondary (to other dental abnormalities: n = 31) diastemata. Quidding was present in 82% of cases, weight loss in 35%, halitosis in 17% and bitting disorders in 12%; 85% of the identified CT diastemata involved mandibular CT and 15% maxillary CT, with caudal CT more commonly affected. Of 273 identified diastemata in the 60 horses, 207 were deemed to have significantly associated periodontal food pocketing and were widened to 4.5-5.5 mm diameter on their occlusal surface using a mechanical burr. The 29 horses with primary diastemata received a median of 1.3 treatments each and at 10 months following their last treatment 72% showed complete remission of signs and 28% showed good improvement. The 31 horses with secondary diastemata received a median of 2.2 treatments each and, at mean 9 months following their last treatment, 48% showed full improvement, 42% good improvement, 6% slight improvement and 3% no improvement. Inappropriate areas of the clinical crown were removed from 4 CT without causing pulpar exposure; one case was reported to have a transient oral infection post treatment and another developed an apical infection in a treated tooth that was unrelated to the diastema widening.

CONCLUSION

Diastema widening is an effective treatment of periodontal pocketing in CT diastemata.

POTENTIAL RELEVANCE

The described treatment of CT diastema widening by trained personnel is an effective and safe treatment, but repeated treatments are often necessary, especially with secondary diastemata.

Young people with spina bifida: transfer from paediatric to adult health care

An expectation of health care for young people with disability is that quality coordinated care continues to be available as they pass from the paediatric to the adult health care system. While individual clinicians provide this service well, the widespread absence of coordinated multidisciplinary care for young people with spina bifida in the adult health care system is a major deficiency. This paper describes the planning and implementation that underpinned the transfer of 10 young people with spina bifida from a paediatric to an adult service. The range of structural, financial and 'cultural' barriers that need to be overcome before patients can be successfully transferred is highlighted; lessons learned from this model may serve to facilitate the development of other transfer services.

Rapid detection of DNA sequence variants by conformation-sensitive capillary electrophoresis

The identification of novel sequence variants, which may be either disease-causing mutations or silent polymorphisms, in large numbers of samples is becoming the rate-limiting step in associating diseases with specific genes. This is particularly true in light of the imminent arrival of the complete reference sequence of the human genome. A number of techniques have been developed to analyze DNA samples for sequence variants rapidly. We describe a new technique, capillary-based conformation-sensitive gel electrophoresis (capillary CSGE) that transfers mutation detection from acrylamide gel to capillary electrophoresis. Capillary CSGE was able to detect 7/7 short insertion/deletions and 16/22 base substitutions in a series of random single-nucleotide polymorphisms and known variants in the lipoprotein lipase and BRCA2 genes. This technique has the potential to screen many megabases of DNA in a single day.

Equine paranasal sinus disease: a long-term study of 200 cases (1997-2009): ancillary diagnostic findings and involvement of the various sinus compartments

REASONS FOR PERFORMING STUDY

There is a lack of objective information on the value of ancillary diagnostic techniques used to investigate equine sinus disease, and also on which sinus compartments are commonly affected in this disorder.

OBJECTIVES

To record the ancillary diagnostic findings used to investigate equine sinus disease and to document which compartments are affected.

MATERIALS AND METHODS

The clinical case records of 200 consecutive cases of sinus disease, including subacute (<2 months' duration) primary (n = 52); chronic (>2 months' duration) primary (n = 37); dental (n = 40); traumatic (n = 13); sinus cyst (n = 26); sinus neoplasia (n = 10); dental related oromaxillary fistula (n = 8); mycotic sinusitis (n = 7) and intra-sinus progressive ethmoid haematoma (n = 7) were retrospectively examined.

RESULTS

Nasal endoscopy showed exudate draining from the sino-nasal ostia in 88% of cases and a sino-nasal fistula was present in 15% of cases. Sinoscopy was performed in 79% of cases and was of great diagnostic value. More recently, 22% of cases had fenestration of the ventral conchal bulla performed to allow sinoscopy of the rostral sinus compartments. Radiography was performed in 97% of cases and showed intra-sinus fluid lines to be common (69% prevalence) in subacute primary sinusitis. Radiographic dental apical changes were not specific to dental sinusitis, e.g. 29% of chronic primary sinusitis cases had radiographic dental changes. Scintigraphy was performed in 20% of cases and was helpful in identifying dental apical changes when radiography was inconclusive. Overall, the caudal maxillary (78% involvement) and rostral maxillary (61%) sinuses were most commonly affected, with the ventral conchal sinus (VCS) (54% involvement) and conchofrontal sinuses (48%) less so. The VCS showed the greatest tendency to contain inspissated pus (present in 46% of all affected VCS).

CONCLUSIONS

Nasal endoscopy, sinoscopy and skull radiography are of great value in diagnosing the presence and causes of equine sinus disease.