ELECTRICAL REMODELLING OF CHRONIC ATRIAL FIBRILLATION

1. It is now recognized that atrial fibrillation (AF) is not a benign condition, as it is associated with a 40% increase in mortality and a doubling of the risk of stroke. 2. The development of AF leads to mechanical, electrophysiological and cellular changes in the atria that tend to sustain AF. This process is known as atrial remodelling. 3. The three electrophysiological elements in the atria that initiate and sustain AF are: (i) shortening of the refractory period and an increase in dispersion; (ii) slowing of conduction velocity; and (iii) the presence of triggerin. foci. 4. As AF is a heterogeneous disorder, therapeutic strategies include the use of devices (pacemakers and atrial defibrillators), radiofrequency ablation (focal ablation or the creation of linear lines) and drug therapy that may reverse a remodelle. atrium.     

Unknown Uterine Sears, Unknown Risks

EDITORIAL COMMENT: We accepted these case reports for publication not only to remind readers that a classical Caesarean scar is more likely than a lower uterine segment scar to rupture or dehisce, but also to stress that women should be counselled appropriately when classical Caesarean section has been performed. Our Australian population is also mobile and women may not return to the same institution or obstetrician for their next confinement. Tracing the details of a previous delivery from another hospital or practitioner even in the same community should be a routine enquiry when a patient has had a Caesarean section in a previous pregnancy but the required information is often difficult to obtain. The woman herse(fis the essential repository for this information. It should also be noted that the recent increase in the number of Caesarean sections performed for fetal indications before 30 weeks' gestation has resulted in more vertical incisions because of a poorly formed lower uterine segment.     

BUERGER'S DISEASE IN HONG KONG: A REVIEW OF 89 CASES

Background : A retrospective analysis of 103 case records from 1978 to 1996 with a provisional diagnosis of Buerger's disease was undertaken at the Department of Surgery, University of Hong Kong, Queen Mary Hospital. The aim of the study was to elucidate the clinical course and evaluate the results of surgical intervention of Buerger's disease in Hong Kong Chinese people. Methods : Fourteen patients were subsequently excluded from the study because of inability to fulfil our diagnostic criteria. Data on clinical presentation, investigations, indications and results of surgical intervention were reviewed. Sympathectomies and arterial reconstructions were performed on 42 and four patients, respectively, for critical ischaemia or rest pain. Outcome was analysed with respect to the rate of ulcer healing, pattern of recurrence and limb loss. Results : The patients were all young male heavy smokers with a mean age of 36.5 years. The majority of patients (80%) presented with ischaemic ulceration or gangrene. Vascular reconstruction was undertaken in four patients and satisfactory long-term results were obtained in three patients. Sympathectomy was able to relieve symptoms in 87% of operated patients and ischaemic ulceration healed in 2.6 (mean) ± 1.7 (SD) months after the operation. If the patient continued to smoke, surgical intervention did not exempt the patient from a relapse or amputation. Conclusion : Sympathectomy provides short-term pain relief and promotes ulcer healing in patients with Buerger's disease but carries no long-term benefit. Complete abstinence from smoking is the only means of arresting the progression of the disease.     

Brain abscess mimicking brain tumor

We review our experience with brain abscesses presenting as primary brain tumor over a 5-year period (1983 to 1988). Four of 66 (6%) patients admitted with the diagnosis of primary brain tumor by computed tomographic scans were found at craniotomy to have brain abscesses. Periapical abscesses found after surgery were determined to be the cause of brain abscess in two of four patients. Our experience suggests that periapical abscess may be a more frequent cause of brain abscess than previously thought, and should be considered before surgery in patients with a suspected brain tumor.     

Comparison of bronchial responsiveness to histamine in asthma, allergic rhinitis and allergic sensitization at the age of 7 years

BACKGROUND: Bronchial responsiveness (BR) to histamine or methacholin is a common finding in adult non-asthmatic patients with allergic rhinitis. OBJECTIVE: We tested whether BR is also present in children with a comparatively short history of allergic rhinitis in a paediatric cohort. METHODS: We performed pulmonary function tests and histamine challenges in a total of 654 children (age 7 years, participants of the German Multicenter Allergy Study) and compared PC20 FEV1 values in children with asthma, allergic rhinitis, asymptomatic allergic sensitization and non-atopic controls. RESULTS: Most pronounced BR to histamine was observed in allergic asthmatics (n = 28), irrespective of the presence or absence of allergic rhinitis. Furthermore, PC(20)FEV(1) values in non-asthmatic children with allergic rhinitis (n = 24) were not significantly different from those seen in asymptomatic atopic (n = 54) or non-atopic controls (n = 92). CONCLUSIONS: In contrast to adult study populations, 7-year-old non-asthmatic children with allergic rhinitis do not show a higher degree of BR than asymptomatic atopic or non-atopic controls. Therefore, secondary preventive measures in non-asthmatic children with allergic rhinitis (such as regular local anti-inflammatory therapy or specific immunotherapy) should be studied and applied more intensely to prevent bronchial hyper-responsiveness (BHR) and asthma in this high-risk group.     

Percutaneous recanalization of chronic subclavian artery occlusion using optical coherence reflectometry-guided radiofrequency ablation guidewire.

Subclavian artery lesion that is associated with low complication rate could be treated by percutaneous intervention effectively. However, the success of endovascular therapy for occlusive lesion may be limited by failure to cross with a guidewire. We describe the use of a system using optical coherence reflectometry for navigation and radiofrequency ablation to enable wire passage through subclavian artery occlusion that could not be crossed by conventional guidewires.     

Attitudes towards mental illness: testing the contact hypothesis among Chinese student nurses in Hong Kong

This study investigated whether previous contact with mental illness affected the attitudes to mental illness (AMI) of general student nurses in Hong Kong — the contact hypothesis. We employed a quasi-experimental design. We compared the attitudes to mental illness of students who had previous contact with mental illness through having taken a psychiatric secondment with those who had not taken a psychiatric secondment. Also, we compared the AMI of: students who had taken other courses related to mental illness with those who had not; those who had a family history of mental illness with those who had not; and those who lived with a mentally ill relative with those who did not. We found that previous contact with mental illness had no significant effect on the attitudes to mental illness of the students. In other words our findings do not support the contact hypothesis. Our sample expressed positive general attitudes to mental illness when presented with general issues about mental illness. However, their attitudes were less positive when presented with specific issues about mental illness that might impinge upon their daily lives. We discuss the implications of these findings for mental health nursing practice, education and research.     

Prolongation of allograft and xenograft survival in mice by anti-CD2 monoclonal antibodies.

Anti-CD2 monoclonal antibodies (mAb) were used to influence graft survival in two transplantation models. Xenogeneic rat islets were transplanted intraportally into mice. Anti-CD2 mAb prolonged xenograft survival and was synergistic with UVB irradiation in prolonging survival. Anti-CD2 mAb was also more potent than an anti-CD4 mAb in this model. Allogeneic cardiac grafts were transplanted across an entire H-2 difference and anti-CD2 mAb prolonged allograft survival in a dose-dependent fashion. Kinetic experiments revealed that anti-CD2 mAb was most potent when administered at the time of allografting. A delay in administration of mAb markedly reduced its immunosuppressive effects. Furthermore, additional doses of mAb given after the initial doses provided no increased immunosuppression and anti-CD2 mAbs did not delay rejection of second-set allografts. These findings support the notion that anti-CD2 mAbs interfere with afferent immunity and that CD2 is most important during the initial steps of an immune response. Investigation of the effect of anti-CD2 mAb on cellular immune functions demonstrated, in agreement with previous results, that it caused antigenic down-modulation of CD2 with relative sparing of CD3, CD4, and CD8 cell surface expression. Concomitantly the MLR, CTL, and NK responses were suppressed.