Population studies of the fragile X: a molecular approach.

The fragile X mutation can now be recognised by a variety of molecular techniques. We report a pilot screening survey of a population of children with mental impairment in which we used Southern blotting methods to detect the fragile X mutation, augmented by cytogenetic studies on children whose phenotype suggested a possible chromosome abnormality. There were 873 children with special educational needs in our survey and 310 fulfilled our criteria for testing. A sample was obtained from 254, of whom four were found to have a full fra(X) mutation (delta L) and none to have a premutation. The number of CGG repeats in our population of X chromosomes was measured by PCR analysis and the genotype at the closely linked polymorphic locus FRAXAC1 established. The distribution of CGG repeat numbers was very similar to that of the control population reported by Fu et al and the distribution of FRAXAC1 alleles almost identical to that of the control population reported by Richards et al. Among the non-fragile X chromosomes, we found a very significant correlation between the size of the CGG repeat and the FRAXAC1 genotype. There was a dearth of A and D genotypes in subjects with a small number of CGG repeats and an excess of the A genotype in those with a large number of CGG repeats. These observations are considered in the light of the reported disequilibrium between the A (and possibly also the D) genotype and the fra(X) mutation.     

A controlled study comparing patients with and without polycystic ovaries undergoing in-vitro fertilization

The outcome of in-vitro fertilization and embryo transfer (IVF—ET)was compared in 76 patients with polycystic ovaries (PCO) diagnosedon pre-treatment ultrasound scan, and 76 control patients whohad normal ovaries and were matched for age, cause of infertilityand stimulation regimen. Despite receiving significantly lesshuman menopausal gonadotrophin (HMG), patients with PCO, ascompared with controls, had significantly higher serum oestradiollevels on the day of human chronic gonadotrophin administration(5940 ± 255 versus 4370 ± 240 pmol/1, P < 0.001),developed more follicles (14.9 ± 0.7 versus 9.8 ±0.6, P < 0.001) and produced more oocytes (9.3 ± 0.6versus 6.8 ± 0.5, P = 0.003). However, fertilizationrates were reduced in the PCO patients (52.8 ± 3.4% versus66.1 ± 3.4%, P = 0.007). There was no significant differencein cleavage rates. The pregnancy rate/embryo transfer was 25.4%in the PCO group and 23.0% in the group with normal ovaries.There were three high order multiple pregnancies in the PCOgroup compared with none in the group with normal ovaries. Ofthe PCO patients, 10.5% developed moderate/severe ovarian hyperstimulationsyndrome (OHSS) compared with none of the controls (P = 0.006).Patients with and without PCO undergoing IVF have comparablepregnancy and livebirth rates. However, it is important to diagnosePCO before ovarian stimulation is initiated as these patientsare more likely to develop moderate or severe OHSS following1VF—ET.     

Role of interleukin 1 in antigen-induced exacerbations of murine arthritis.

The mechanism underlying the chronic and intermittent course of rheumatoid arthritis is not elucidated. In the present study, the role of interleukin 1 (IL-1) was investigated in exacerbations of antigen-induced arthritis in mice. A flare-up of smoldering inflammation (weeks 3 to 4 of antigen-induced arthritis) was inducible by injection of a small amount of methylated bovine serum albumin into the hypersensitive knee joint. Immunohistochemistry showed IL-1 expression in the synovial lining layer and in focal areas of the inflamed synovium during the flare-up. IL-1 was also measured in 1-hour culture supernatant of synovial tissue taken during the flare-up by a bioassay. The expression of both immunoreactive and bioactive IL-1 in the hypersensitive joint peaked around 6 hours after antigen (2 micrograms of methylated bovine serum albumin) injection and declined thereafter. Antigen rechallenge induced an acute joint swelling of the arthritic joint but not in the naive joint of the sensitized mouse, yet synovia of both joints produced IL-1 after antigen injection. Remarkably, a single intravenous injection of rabbit anti-IL-1 alpha and -beta antibodies 1 hour before antigen rechallenge neutralized IL-1 in the joint. Anti-IL-1 treatment significantly reduced the antigen-induced joint swelling (30 to 40%) but did not affect the profound influx of polymorphonuclear cells in the onset of the exacerbation. However, a profound relief of the inflammation (synovitis) was obtained by IL-1 blockade on day 4 of the exacerbation. Chondrocyte proteoglycan synthesis was markedly suppressed in the antigen-challenged naive knee joints suggesting that this was a direct IL-1 effect as the inflammation was insignificant. Anti-IL-1 treatment was able to maintain chondrocyte proteoglycan synthesis in the antigen-rechallenged joint, which was highly suppressed in the control group. Furthermore, the enhanced proteoglycan breakdown in the antigen-rechallenged joints was significantly decreased in the anti-IL-1 group. We concluded that IL-1 is an important mediator in exacerbations of murine arthritis, and amelioration of cartilage pathology was obtained with anti-IL-1 antibody treatment.     

Subtyping of Mycoplasma pneumoniae isolates based on extended genome sequencing and on expression profiles

Mycoplasma pneumoniae isolates from patients, collected over a period of 12 years in Germany, were characterized by various methods (parameters) including multilocus sequence typing, restriction fragment length polymorphisms, Western blotting with mono-specific antibodies directed against selected proteins or with polyspecific antibodies directed against the Triton X-114-soluble protein fraction, and two-dimensional gel electrophoresis. The results for 91 isolates from Germany, which were complemented with 14 isolates from the USA and 10 isolates from France, clearly showed that M. pneumoniae is a highly uniform species and that most of the isolates could be assigned to one of the two subtypes 1 and 2. The members of one subtype differ from the other with respect to the sequence of the P1 gene, the ORF6 gene, the P65 gene, and by a typical DNA restriction fragment pattern. We observed four isolates (variants), which seemed identical by the above mentioned criteria, but did not belong to either one of the two subtypes. They showed most of the subtype 2-specific features, but differed in the sequence of the P1 gene and showed a variation in the restriction fragment pattern. The appearance of subtype 1 or 2 over the last 12 years in Germany showed a dominance of subtype 1 between 1989 and 1996 and a dominance of subtype 2 between 1997 and 1998. The variant (neither subtype 1 nor subtype 2) was only detected in 1991 and 1995 but it had no epidemiological consequences.     

Peripheral blood chromosome aberrations in MDS.

The frequency of non-clonal structural and numerical chromosome aberrations in peripheral blood lymphocytes of 51 patients with MDS and 37 age-matched hematologically normal subjects is assessed. The frequency of aneuploid cells (p less than 0.001) and of structural aberrations (p less than 0.005) was significantly higher in MDS patients than in normal subjects, but showed no relationship with FAB type or with the presence of clonal karyotype abnormalities in the bone marrow. Exchange configurations were only observed in MDS patients (27.5%). The data also suggest that there may be an association between high peripheral blood aberration levels and rapidly progressive disease. This may indicate increased mutagen sensitivity and have implications for treatment.     

Comparative evaluation of the API 20S system and the automicrobic system gram-positive identification card for species identification of streptococci.

Two commercial methods, the API 20S system (API; Analytab Products, Inc., Plainview, N.Y.) and the Gram-Positive Identification Card (GPI; Vitek Systems, Inc., Hazelwood, Mo.), were evaluated without additional tests for the identification of 241 streptococcus strains. Organisms included 60 beta-hemolytic strains, 36 group D strains, 26 Streptococcus pneumoniae strains, and 119 viridans streptococcus strains. API correctly identified to species 68.3% of beta-hemolytic strains, 86.1% of group D strains, 53.9% of S. pneumoniae strains, and 12.6% of viridans streptococci. This method provided excellent identification of group A and B and S. faecalis strains. Overall, API correctly identified 41.9% of strains to species, with 41.1% good likelihood but low selectivity, 15.8% incorrect, and 1.2% not identified. GPI correctly identified to species 58.3% of beta-hemolytic strains, 97.2% of group D strains, 80.8% of S. pneumoniae strains, and 57.2% of viridans streptococci. Group A, B, and D strains were all accurately identified by this system. Overall, GPI correctly identified to species 66.0% of strains, with 8.7% correct preliminary identification, 20.8% incorrect, and 4.6% not identified. Both methods represent a worthwhile advance in streptococcal identification. Neither system, however, can be recommended for species identification of the viridans group at this time.     

DADOS-Survey: an open-source application for CHERRIES-compliant Web surveys

Background  

The Internet has been increasingly utilized in biomedical research. From online searching for literature to data sharing, the Internet has emerged as a primary means of research for many physicians and scientists. As a result, Web-based surveys have been employed as an alternative to traditional, paper-based surveys. We describe DADOS-Survey, an open-source Web-survey application developed at our institution that, to the best of our knowledge, is the first to be compliant with the Checklist for Reporting Results of Internet E-Surveys (CHERRIES). DADOS-Survey was designed with usability as a priority, allowing investigators to design and execute their own studies with minimal technical difficulties in doing so.     

Comparison of two automated multichannel haematology analysers in domestic animals

Blood samples from 33 dogs, 28 cats, 24 horses and 25 cattle were analysed in duplicate on the Coulter Counter S-Plus IV and the Baker 9000 multichannel haematology analysers. The precisions of each instrument and the correlations between the instruments were evaluated. The precisions of both systems were good but, the Baker 9000 system showed more variability between duplicate determinations for all parameters. The Baker 9000 had better precision for white blood cell count, haemoglobin concentration, and MCV. Correlations between the two instruments were excellent except for MCHC. Neither analyser reliably provided feline platelet counts and the Baker 9000 also failed to report error messages for 8 of 10 apparently false platelet counts. The Coulter instrument consistently reported higher haemoglobin concentrations and higher feline and lower canine white blood cell counts than the Baker 9000.     

Nutritionally variant Streptococcus pyogenes from a periorbital abscess.

A nutritionally variant Streptococcus pyogenes strain was isolated from a periorbital abscess. The organism was identified with the use of three rapid biochemical test kits, and the group A antigen was detected by conventional serology as well as direct antigen detection tests.