The haemodynamic effect of prophylactic peri-operative dopexamine in coronary artery bypass patients

Twenty-three low risk coronary artery bypass graft patientsunderwent a controlled study of the effects of prophylacticperioperative dopexamine hydrochloride on haemodynamic indicesand peripheral perfusion. The infusion commenced following inductionof anaesthesia and continued for 24 h postoperatively. The studydemonstrated that dopexamine significantly increased cardiacindex compared with the control group (P<0.05) and that thiseffect was mediated through an increase in both left ventricularstroke volume index and heart rate (P<0.05). This was associatedwith a significantly lower systemic vascular resistance (P<0.05),without an increase in left ventricular stroke work index inthe dopexamine group. Despite normal pre-operative left ventricularfunction, both groups exhibited a fall in pH (P<0.05) relativeto baseline levels. This fall in pH began prior to cardiopulmonarybypass and persisted in the early postoperative period in bothgroups, suggestive of tissue hypoperfusion and oxygen deficiency.These indices normalized more rapidly in the dopexamine group,suggesting a more rapid reversal of an intra-operative oxygendebt in this group. The study demonstrates the mechanism ofaction of dopexamine on cardiac function and peripheral perfusionduring cardiac surgery and shows that the inodilator propertiesduring cardiac surgery are useful haemodynamically and facilitateearly reversal of tissue hypoperfusion and oxygen debt in thisenvironment.     

EXTRACORPOREAL PHOTOCHEMOTHERAPY IN PROGRESSIVE SYSTEMIC SCLEROSIS

Background. Extracorporeal photochemotherapy, an immune-modulating form of therapy, has been shown to be effective in the treatment of autoimmune diseases. We evaluated the effects of extracorporeal photochemotherapy in the treatment of patients with progressive systemic sclerosis (pss). Methods. Nine patients with active progressive systemic sclerosis were treated with extracorporeal photochemotherapy on 2 successive days monthly. The duration of therapy ranged from 6 to 21 months. Results. A significant improvement was noted in the skin, musculoskeletal system, functional index, and symptoms including Raynaud's phenomenon, dyspnea, fatigue, dysphagia, and arthralgias, as well as improvement of cutaneous ulcers. Stabilization of the pulmonary function studies was also noted in the majority of patients over the course of therapy. No serious side effects were noted throughout the course of therapy in the 9 patients. Conclusions. The results suggest that photopheresis may be beneficial in selected early cases of progressive systemic sclerosis.     

Clearance of Sulfuric Acid-Introduced 35S from the Respiratory Tracts of Rats, Guinea Pigs and Dogs Following Inhalation or Instillation

Clearance of Sulfuric Acid-Introduced ³⁵S from the RespiratoryTracts of Rats, Guinea Pigs and Dogs Following Inhalation orInstillation. Dahl, A.R., Felicetti, S.A., and Muggenburg, B.A.(1983). Fundam. Appl. Toxicol. 3: 293–297. The clearanceof sulfuric acid-introduced ³⁵S from the upper and lower respiratorytracts of rats, guinea pigs and dogs was measured. Sulfuricacid was administered by instillation and by inhalation foreach species. Clearance into the blood and gastrointestinaltract was measured along with determination of ³⁵S remainingat the site of administration at sacrifice. Different ratesof clearance from different sites within the dog lung were indicatedwith rates of clearance increasing with decreasing airway diameter.Half-times of clearance from all sites in the lung and for allspecies were from 2–9 min. There appeared to be some speciesdifferences, with clearance for dogs being slower than for guineapigs, which was slower than for rats. Upper respiratory tractclearance was much slower than for lung and may not have beenprimarily by way of the blood. The data indicate that the clearanceof sulfuric acid-introduced ³⁵S in vivo is faster than previousstudies in isolated perfused lungs had indicated. The resultsmay be general for water soluble, ionized chemical species.     

Among Young Adults, College Students and Graduates Practiced more Healthful Habits and made more Healthful Food Choices than did Nonstudents

Objectives Health-related characteristics and habits and food choices of young adults were compared for three groups: college students, college graduates, and nonstudents.Design Subjects completed a mailed survey that included questions about demographics, attitudes, and behaviors and a food frequency questionnaire. Main outcome measures were health-related characteristics and habits and food choices.Subjects Female (n=758) and male (n=580) 18- to 24-year-olds in nine states who were selected randomly by zip code in each state. The response rate averaged 43% for all states.Statistical analyses performed Analysis of variance or χ² tests were applied to health-related personal characteristic variables and the Kruskal-Wallis analysis of variance was applied to food consumption variables for women and men separately.Results According to self-reported heights and weights, female nonstudents were more often overweight than female students or graduates. Nonstudents of both genders reported smoking more often than students or graduates. College students and graduates ate more grain foods high in dietary fiber, more fruits and dark-green vegetables, and more lower-fat milk and meats than non students.Conclusions/applications Non students were at greater health risk for some chronic illnesses, because of poorer health habits and food choices, than were college students and graduates. The behavior of nonstudents implies weaker response to messages promoting weight control, smoking cessation, and observance of the Dietary Guidelines for Americans than behavior exhibited by students or college graduates. Health promotion efforts could be enhanced by identifying demographic, educational, situational, and formative influences on positive health and dietary behaviors of young adults.     

Current Problems Associated with Toxicity Evaluation of Medical Device Materials and Future Research Needs

The application of toxicology to the evaluation of medical devicematerials is reviewed. Strengths and weaknesses of systemicand local toxicity models are described. Developments neededto improve the methodology and predictability of assays forimmunotoxicity and particulate toxicity are identified. Emergingmethds are introduced for assessing adhesion, fibrosis, andblood compatibility.     

Dynamic Beat-to-Beat QT-RR Relationship During Physiotherapy Effort in Elderly Patients Without Primary Heart Disease

The ECGs from 18 patients hospitalized in a rehabilitation setting, following surgery for hip fracture, were examined to characterize the dynamic behavior of uncorrected QT interval in relation to changing RR interval during physiotherapy effort. ECG waveforms were analyzed to extract beat-to-beat QT and RR intervals using a computerized ECG Analyzer (CEA-1100). The method of defining the QT and RR intervals is based on performing multiple cross-correlations that enable rejection of artifacts from the analysis. The relationship between the RR and QT intervals was found using the following general formula QTi = cRRi-1b. Linear regression was performed on the logarithms of QT and RR measurements obtained to estimate the constant (a = log c) and the slope (b) values, reflecting the dynamic change of QT during physiotherapy effort. Having these two values, the dynamic QT extrapolated to a heart period of 1 second (QTcd) was calculated. The results were compared to the conventional corrected static QT according to the Bazzet formula (QTcs). The mean values of constants (a = log c) and slopes (b) over all patients were found to be 1.61 +/- 0.23 and 0.33 +/- 0.08, respectively, giving a QT (ms) heart-period (ms) dynamic relation of QTi = 41 x RR(i-1)0.33. The correlation between the dynamic QT and the static QT intervals was not significant. The mean values of the QTcd and QTcs intervals were significantly different (392 +/- 25 ms vs 434 +/- 28 ms; P < 0.0001). This dynamic measurement method of QT intervals may provide additional information on normal and abnormal cardiac repolarization in health and disease, helping in the diagnosis of cardiac disorders and arrhythmia risk.     

MALIGNANT SYPHILIS (LUES MALIGNA) AND CONCURRENT INFECTION WITH HIV

Background. During the past 2 1/2 years we observed six patients who had a reactive serology for syphilis, of which four developed widespread noduloulcerative and two vesiculonecrotic lesions. The purpose was to report the occurrence of lues maligna, a rare form of secondary syphilis, in five patients infected with the human immunodeficiency virus (HIV) and in one patient with risk factors for infection. Methods. Tzanck preparations, viral cultures, and skin biopsies were performed to evaluate the etiology of the lesions. Results. Syphilis serology titers ranged from 1:32 to 1:128 and in one instance was as low as 1:8. Such titers can also be found in patients with the latent form of syphilis. Therefore, confirmation of the clinical diagnosis of lues maligna was dependent on skin biopsies that were compatible with secondary syphilis and negative viral studies that excluded varicella, disseminated varicella-zoster or herpes simplex. Lues maligna takes an aggressive course in HIV-infected patients since four of the patients required hospitalization and the two patients who refused to complete treatment, subsequently developed more severe skin and constitutional symptoms. Conclusions. HIV-infected patients are at risk for developing lues maligna. Despite its malignant presentation, lues maligna lesions respond rapidly to treatment with penicillin. Secondary syphilis should be added to the list of diseases known to be more aggressive in HIV-infected patients.