A systematic genomewide linkage study in 353 sib pairs with schizophrenia

We undertook a genomewide linkage study in a total of 353 affected sib pairs (ASPs) with schizophrenia. Our sample consisted of 179 ASPs from the United Kingdom, 134 from Sweden, and 40 from the United States. We typed 372 microsatellite markers at approximately 10-cM intervals. Our strongest finding was a LOD score of 3.87 on chromosome 10q25.3-q26.3, with positive results being contributed by all three samples and a LOD-1 interval of 15 cM. This finding achieved genomewide significance (P<.05), on the basis of simulation studies. We also found two regions, 17p11.2-q25.1 (maximum LOD score [MLS] = 3.35) and 22q11 (MLS = 2.29), in which the evidence for linkage was highly suggestive. Linkage to all of these regions has been supported by other studies. Moreover, we found strong evidence for linkage (genomewide P<.02) to 17p11.2-q25.1 in a single pedigree with schizophrenia. In our view, the evidence is now sufficiently compelling to undertake detailed mapping studies of these three regions.

Linkage analysis of a large Swedish kindred provides further support for a susceptibility locus for schizophrenia on chromosome 6p23

Several reports have indicated genetic linkage between markers on the short arm of chromosome 6 and schizophrenia. However, significant threshold levels were not always achieved, and the chromosomal regions identified are large and different in different families. One way to decrease the problem of heterogeneity is to study a single extended pedigree. Here we report the analysis of a very large, previously undescribed pedigree from northern Sweden that includes 31 affected individuals. We typed 16 markers spanning 40 cM on the short arm of chromosome 6. Linkage analysis was performed only with the affected individuals. Suggestive lod scores (maximum 2.6) were obtained with markers on chromosome 6p23 in a single branch of the large pedigree indicating possible heterogeneity inside the family. A haplotype comprising markers from D6S309 to D6S1578 was found to segregate with the disease. This chromosomal region is included within a segment proposed to contain a susceptibility gene for schizophrenia by many other investigators. Our results thus give further support for a possible localization of a susceptibility locus for schizophrenia in 6p23 and help to narrow the candidate chromosomal region to the segment included between markers D6S309 and D6S1578.

Anticipation in Swedish families with schizophrenia

Nineteen parent-offspring pairs obtained from 14 two-generation families with available medical records and diagnosis of schizophrenia were studied to compare the ages of onset of the parent generation with those of the offspring generation. The mean age of onset for the parent generation was 37.3 +/- 6.0 years and for the offspring generation was 20.8 +/- 4.4. The mean difference was thus 16.5 +/- 6.2, suggesting the occurrence of anticipation in schizophrenia (p < 0.001). Although some ascertainment biases (like reduced fertility in early-onset parents or early detection of symptoms in offsprings of affected parents) may partially contribute to the occurrence of anticipation, this study replicates recent reports of anticipation in several neuropsychiatric disorders, some of which have been shown to be associated with unstable expansions of trinucleotide repeats in the genomic DNA.

Evaluation of conventional press-and-breathe metered-dose inhaler technique in 501 patients

Conventional press-and-breathe metered dose inhalers (MDIs) are widely prescribed but are often difficult for many patients to properly use. A total of 501 patients from different medical specialties were enrolled in this study, which evaluated how the patients used their MDIs. Using a conservative method (minimum number of errors) of determining errors, we found that 388 (77.5%) of the patients made at least one error when demonstrating how they use their MDI for two observers. Using a liberal (maximum number of errors) method of analysis, we found that 447 (89.2%) of the patients made at least one error. There was no difference in errors made stratified by patient gender, patient age, or the medical specialty that treated the patient's pulmonary disease. The two most common errors made by patients were failure to breathe out to functional residual capacity before actuation (225 by minimum method, 280 by maximum method) and not actuating the canister at the start of inhalation (207 by minimum method, 323 by maximum method). Of the patients with improper timing of actuation, the majority (121 patients by minimum method and 187 patients by maximum method) actuated the canister early. In this large patient sample, regardless of which medical specialty provided the treatment, the majority of the patients evaluated had less than optimal MDI technique. Routine assessment of MDI technique should be instituted as standard practice care.

Does the acetyl group of aspirin contribute to the antiinflammatory efficacy of salicylic acid in the treatment of rheumatoid arthritis?

In a multicenter, double-blind, parallel-group study, 233 patients with classical or definite RA who demonstrated disease flare during a prestudy washout period were randomized to 12 weeks of treatment with either the nonacetylated salicylate, salsalate (salicylsalicylic acid), or aspirin. Of the 150 patients who completed the study, 83 received salsalate and 67 were treated with aspirin. Doses of the two drugs were calculated to provide equal amounts of bioavailable salicylic acid. The efficacy of salsalate and aspirin, as measured by all the usual variables, was equivalent but aspirin-treated patients had a higher incidence of severe gastrointestinal problems. Thus, this study demonstrated that the acetyl group of aspirin does not enhance the anti-inflammatory efficacy of salicylic acid in RA.

Reduced risk of NSAID gastropathy (GI mucosal toxicity) with nonacetylated salicylate (salsalate): an endoscopic study

This randomized, investigator-blinded, parallel group endoscopic study evaluated the effects of salsalate and naproxen on the gastroduodenal mucosa over a 3-month period in patients with RA. Using therapeutic doses of the drugs, 8 of 21 patients (38%) in the naproxen group had endoscopically shown active ulcers (seven patients) or diffuse erosions (one patient), whereas none of the 18 patients treated with salsalate (0%) had such lesions (P = .003). Five of the eight naproxen-treated patients with evidence of GI damage were asymptomatic at the time of endoscopic verification of their lesions. The most significant disadvantage of salsalate was its higher incidence of otologic problems accounting for six of the nine discontinuations with salsalate. However, the findings of this study suggest that patients receiving salsalate are at lower risk for developing significant gastropathy than those treated with naproxen. The relative benefit-to-risk ratio of salsalate indicates that this drug should be considered as a significant alternative NSAID therapy.

An endoscopic comparison of the gastroduodenal injury seen with salsalate and naproxen

Forty endoscopically normal healthy subjects were randomized to receive either BID salsalate (3500 mg/day) or BID naproxen (750 mg/day) for 14 days followed by repeat endoscopic examination. Gastroduodenal lesions were found in 55% (11/20) of the subjects taking naproxen, and 10% (2/20) of those taking salsalate (p = 0.002). Twenty-five percent (5/20) of the subjects taking naproxen and none of the subjects taking salsalate were noted to have severe gastric injury (p = 0.003). There was no difference between the 2 groups in subjective gastrointestinal system adverse experiences. Overall, 95% (19/20) of subjects taking salsalate reported at least 1 adverse experience compared with 60% (12/20) of those taking naproxen (p = 0.02). This was due primarily to the higher number of subjects taking salsalate reporting reversible tinnitus or hearing loss. There was no significant treatment difference in adverse experiences reported for any other organ system. The results of our study support previous observations in patients with rheumatoid arthritis that salsalate produces less gastroduodenal mucosal toxicity than the widely used antiinflammatory agent, naproxen.