Shoulder instability: impact of glenohumeral arthrotomography on treatment

We used arthrotomography to study the glenoid labrum in 114 patients. Sixty-nine of the patients had anatomic instability of the shoulder (including recurrent dislocation and subluxation of the shoulder), and 45 patients had functional instability of the shoulder (denoted by chronic pain, clicking of the joint, and the sensation that an unstable condition exists without the objective signs of it). Labral tears were revealed arthrotomographically in 86% of the patients with anatomic instability, while only 40% of the patients with functional instability had labral abnormalities, and these were primarily of minor severity. Fifty-six patients (44 of whom had anatomic instability; 12, functional instability) required surgery. The surgical findings were correlated with the arthrotomographic findings, and no false-positive results were revealed. However, arthrotomography demonstrated only part of the pathologic condition of two patients. These results confirm that there is a strong correlation between labral pathologic conditions and anatomic instability of the shoulder. Arthrotomographic studies have a great impact on the selection of therapy in cases of both anatomic and functional instability of the shoulder.     

Exercise induced vasodepressor syncope.

Five cases of exercise induced pure vasodepressor syncope in patients without significant structural heart disease are reported. Hypotension and symptoms of syncope or pre-syncope were induced by treadmill exercise testing and in each case limited exercise performance. Evidence of inappropriate peripheral vasodilation, probably as a consequence of ventricular mechanoreceptor stimulation, was shown in all five patients. Head up tilt testing resulted in hypotension in four patients and isoprenaline infusion in the supine position resulted in hypotension in the fifth. These patients had a new condition of exercise induced neurally mediated (vasodepressor) syncope without appreciable structural cardiac abnormalities.     

Discovering genes: the use of microarrays and laser capture microdissection in pain research

The DNA microarray is a powerful, high throughput technique for assessing gene expression on a system-wide genomic scale. It has great potential in pain research for determining the network of gene regulation in different pain conditions, and also for producing detailed gene expression maps in anatomical areas that process nociceptive stimuli. However, for the potential of this high throughput technology to be realised in pain research, microarrays need to be combined with other technologies. Laser capture microdissection is capable of isolating small populations of homogenous cells, allowing distinct areas involved in nociceptive processing to be examined. In combination with sophisticated PCR-based amplification protocols this technique provides sufficient amounts of messenger RNA (mRNA) for application to microarrays. Aside from the technological issues, a difficult task in any microarray study is the analysis of the resulting enormous data set to reveal the key genes, whose regulation is central to the phenotypic changes observed. For this to be achieved, the methods of data analysis, pattern searching and feature recognition, and bioinformatics have to be properly deployed all within the context of an appropriate statistical design. These issues are especially relevant to pain research where interindividual and interpopulation variation is likely to be high, and where polymorphisms can greatly affect nociceptive sensitivity and susceptibility to pain conditions. Methods for assessing the function of new candidate genes identified in microarray screening experiments are also discussed.     

Catheter ablation by low energy DC shocks for successful management of atrial flutter.

OBJECTIVE--To assess the effects of low energy ablation of the substrate for atrial flutter. DESIGN--Initial retrospective analysis of patients undergoing low energy ablation of the atrioventricular node for refractory atrial flutter (group 1) was followed by a prospective assessment of low energy ablation in the posterio-inferior right atrium for the same condition (group 2). SETTING--Tertiary referral centre for management of cardiac arrhythmias. PATIENTS--Seven men (aged 50-67 years) with refractory atrial flutter. INTERVENTIONS--Multiple (3-10) low energy DC shocks with a cumulative energy of 100-245 J in the region of the atrioventricular node in group 1 and 12-15 low energy DC shocks (cumulative energy 110-235 J) guided by the anatomical landmarks of the triangle of Koch and applied directly to the atrial wall. MAIN OUTCOME MEASURE--Freedom from recurrence of atrial flutter. RESULTS--In group 1 despite initial complete atrioventricular block in three patients, atrioventricular conduction had resumed in all by one month. All four, however, were in sinus rhythm at follow up six to 13 months later. Two of the three patients in group 2 were free of atrial flutter at follow up three to four months after ablation. CONCLUSION--Ablation of the atrial flutter substrate with low energy DC shocks is feasible. Precise electrophysiological mapping is not necessary.     

Sexual behavior and attitudes of University students in Northern Ireland

Two surveys of a Northern Ireland student sample were conducted in 1987 and 1988. A total of 419 female and 201 male subjects completed self-administered anonymous questionnaires concerning their behavior, knowledge, and attitudes towards sex, AIDS, homosexuality, contraception, and relationships. Results indicated a relatively low level of sexual experience, and for those with experience, relatively few partners. The possible influences of gender and religiosity on sexual behavior and attitudes, in the context of Northern Ireland, are discussed. Subjects reported considerable variation in the amount of sex education, but the majority received little or none. This student sample held relatively conservative attitudes towards love, sex, and marriage and this was particularly true for females and for regular churchgoers. In addition, attitudes towards homosexuality were negative (particularly among regular churchgoers). Attitudes towards contraception were more positive than expected among Catholic subjects, and few indicated that they would refuse to use contraceptives on principle. Responses to items about AIDS were highly uniform, suggesting that much of the information made available to the public has been absorbed. However, the lack of uniformity of response to more general items about sex, relationships, and contraception may indicate that fundamental changes in sexual behavior are unlikely to be brought about by influencing a rather narrowly defined set of attitudes about AIDS.     

Linkage of the MHC to familial multiple sclerosis suggests genetic heterogeneity. The Multiple Sclerosis Genetics Group

Multiple sclerosis (MS) is a demyelinating autoimmune disease of the central nervous system. While its etiology is not well understood, genetic factors are clearly involved. Until recently, most genetic studies in MS have been association studies using the case-control design testing specific candidate genes and studying only sporadic cases. The only consistently replicated finding has been an association with the HLA-DR2 allele within the major histocompatibility complex (MHC) on chromosome 6. Using the genetic linkage design, however, evidence for and against linkage of the MHC to MS has been found, fostering suggestions that sporadic and familial MS have different etiologies. Most recently, two of four genomic screens demonstrated linkage to the MHC, although specific allelic associations were not tested. Here, a dataset of 98 multiplex families was studied to test for an association to the HLA-DR2 allele in familial MS and to determine if genetic linkage to the MHC was due solely to such an association. Three highly polymorphic markers (HLA-DR, D6S273 and TNFbeta) in the MHC demonstrated strong genetic linkage (parametric lod scores of 4.60, 2.20 and 1.24, respectively) and a specific association with the HLA-DR2 allele was confirmed (TDT; P < 0.001). Stratifying the results by HLA-DR2 status showed that the linkage results were limited to families segregating HLA-DR2 alleles. These results demonstrate that genetic linkage to the MHC can be explained by the HLA-DR2 allelic association. They also indicate that sporadic and familial MS share a common genetic susceptibility. In addition, preliminary calculations suggest that the MHC explains between 17 and 62% of the genetic etiology of MS. This heterogeneity is also supported by the minority of families showing no linkage or association with loci within the MHC.