Novel coronary interventional devices: an update.

Interventional cardiologists today are overwhelmed by a hugh array of new high technology investigatory devices at their disposal for the treatment of coronary arterial obstructive disease. These include the various atherectomy and laser devices, developed and introduced into clinical practice with the promise and intent of solving the limitations of conventional balloon angioplasty, namely those of acute closure and restenosis. But as more experience and data are obtained from the application of these devices, it is becoming clear that the latter have generally not been able to accomplish what they were intended to do. Although the immediate success rates have been uniformly high, acute closure has persisted and restenosis remains unabated. Nevertheless, some of these new devices have shown some fairly encouraging results in specific clinical circumstances. The targeted use of these instruments may prove to be a step in the right direction. This article reviews the current state of the art and the potential utility of certain of these devices.     

Effects of potassium channel blockers on the negative inotropic responses induced by cromakalim and pinacidil in guinea pig atrium.

The K+ channel openers cromakalim and pinacidil induced a concentration-dependent reduction in atrial contraction force with EC50 values of 25 +/- 2 and 37 +/- 2 mumol/l, respectively. This depressant effect was antagonised by 50 mumol/l tacrine which displaced the concentration-response curves of cromakalim and pinacidil to the right. The respective DR50 values were 3.8 and 2.3. Increasing the tacrine concentration (100 and 500 mumol/l) produced no additional effect on the concentration-response relationships. Addition of 1 mumol/l atropine enhanced the antagonism due to tacrine by increasing the DR50 value from 3.8 to 6.5 for cromakalim and from 2.3 to 5.2 for pinacidil. Glibenclamide, an ATP-sensitive K+ channel blocker, competitively inhibited the negative inotropic effects of cromakalim and pinacidil. The respective dissociation constants for glibenclamide against cromakalim and pinacidil were 0.57 and 0.35 mumol/l. Neither apamin nor variation in external Ca2+ concentration affected the negative inotropic effects of the K+ channel openers. It was suggested that the mechanical effects of cromakalim and pinacidil are mediated through the ATP-sensitive K+ channels in the heart.     

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.     

Mycobacterium marinum infection of the hand and wrist. Results of conservative treatment in twenty-four cases

Inadequate débridement, extensive scarring, and breakdown of the wound have been commonly encountered after surgical débridement has been employed as the initial treatment of infection with Mycobacterium marinum involving the deep structures of the hand. Because of our disappointment with the results of this form of treatment, from 1982 to 1986 we treated twenty-four patients who had such an infection with rifampicin and ethambutol after a diagnostic biopsy was done. Surgical treatment was deferred until it was determined that the infection had not been controlled by the chemotherapy. The clinical outcome for these patients could be divided into three patterns: eleven patients (Group I) had a good result with no complications, three patients (Group II) had delayed healing of the wound, and ten patients (Group III) did not have a good response to conservative treatment and required one or more surgical débridements. Complications were sometimes associated with use of the drugs, and loss of visual acuity was a concern in three patients. In twenty-one (87 per cent) of the patients, at follow-up the function of the treated hand was equal to that of the other hand. Persistent pain, a discharging sinus, and previous local injection of steroids were unfavorable prognostic factors. If these factors are present, surgical débridement is advised.     

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.