Studies on the Modulating Effects of Retinoic Acid and Retinol Acetate Using Dye Transfer and Metabolic Cooperation Assays

The effects of retinoic acid and retinol acetate on gap junctionalcommunication were examined in two in vitro tests. Rat liverepithelial cell line IAR 203 was used for dye transfer assays,and hamster lung fibroblast V79 cells were used for metaboliccooperation assays. A reversible dose-dependent inhibition ofdye transfer was detected after a 1-hr treatment with retinoicacid or retinol acetate at concentrations ranging from 10 to50 µM. On the other hand, enhancement of dye transferwas observed after a 24-hr treatment with retinoic acid at 0.1µM. A dose-dependent inhibition of metabolic cooperationwas obtained with retinoic acid at noncytotoxic concentrationsranging from 5 to 50 µM. Retinoids and TPA (1 ng/ml) actedsynergistically in their inhibition of cell communication. Thus,the assays appear to be complementary: the dye transfer assaywas useful in studying the time course and the reversibilityof the inhibition or enhancement of dye transfer, whereas themetabolic cooperation assay was effective in quantifying theinhibitory effect of TPA or retinoids and interactions betweenthem.     

Transformation: are nurse leaders in critical care ready?

Aim The aim was to determine whether nursing leaders met the criteria for transformational and/or transactional leadership. Background Many changes have occurred in South Africa and are reflected in the health-care systems. As a result, it has become crucial to source leaders who are able to manage the change process effectively so as to ensure the success and survival of our health-care organizations. Methods The 45-item Multifactor Leadership Questionnaire (Rater) was completed by 41 respondents out of a population of 121. A proportional stratified simple random sampling technique was used to select the raters of seven leaders. Results Most nursing leaders role-modelled the culture of the organisation but did not stimulate their followers intellectually and did not demonstrate innovative motivation or individual consideration. Consequently, their followers may exhibit a lack of commitment to collective goals, with detrimental effects on the health-care organisation as a whole. Conclusions and implications for nursing managers Nursing leaders should be trained to become transformational leaders so as to encourage their followers to become innovative and motivated to render high quality nursing care.     

Hemolytic-uremic Syndrome: An Analysis of the Natural History and Prognostic Features

Sixty-seven children with hemolytic-uremic syndrome (HUS) were admitted between 1974 and 1981. Of these, 52 (78 %) were aged less than 3 years. All children had acute renal failure and 48 (72 %) required peritoneal dialysis. The etiology in twenty cases varied from bacterial and viral infections (7 and 5 cases, respectively) to renal irradiation with chemotherapy (2) and preexisting glomerulopathy (1). 5 (7 %) children died during the acute phase of the illness. Long-term follow-up (mean 3 years 3 months) of 56 cases showed that 37 children (60 %) had so far experienced no functional sequelae and 8 (13 %) only mild sequelae while 3 (5%) were on iterative hemodialysis, 3 had severe chronic renal failure and high blood pressure (HBP) and 5 (8 %) had HBP and normal kidney function. While the recovery rate was approximately 60 % in all age groups, the mortality rate and serious after-effects were twice as frequent (42 %) in children over 3 years of age as in those less than 3. Renal histology (total of 37) showed 12 cases of cortical necrosis, 22 of glomerular thrombotic microangiopathy (TMA) and 3 arterial TMA. Prognosis was poor for all cases of arterial TMA and 58 % of those exhibiting cortical necrosis.     

Infected Endocardial Pacemaker Electrodes: Successful Open Intracardiac Removal

The long-term results after open intracardiac removal of infected pacing electrodes are presented. Methods: between 1985 and 1990 open intracardiac removal of 19 infected pacing electrodes was performed in seven patients (six male and one femalel, with a mean age of 56 years. The indications were; persisting bacteremia in three; generator pocket infection in four; endocarditis in one; and ventricular tachycardia caused by retracted electrodes in one. All electrodes were fixed in the right heart and extraction by closed methods failed. Percutaneous catheter techniques were not applied in these seven patients. In five patients two ventricular electrodes had to be removed, and in two patients a single one. A total of seven atrial electrodes were removed in six patients (one electrode each in five patients; two electrodes in one patient). All atrial and two ventricular electrodes could be removed through a pursestring suture without use of a pump oxygenator. For the removal of ten ventricular electrodes in six patients (two electrodes each in four patients; 1 electrode each in two patients) a right-sided atriotomy was necessary with cardiopulmonary bypass (CPB). Simultaneously, five new pacing systems were implanted. Results; there were no early or late mortalities. In January 1991, all seven patients are alive and in a mean New York Heart Association Class 1,3 of heart failure after a mean interval of 33 months. In all cases the infection could be controlled with a simultaneous antimicrobial chemotherapy and the postoperative period was free of major complications. Conclusion; open intracardiac removal of retained pacing electrodes with or without use of CPB is a safe procedure without major complications. It is mandatory for all infected pacing electrodes that cannot be extracted by closed methods.     

LEPROMATOUS LEPROSY WITH EXTENSIVE TRUNCAL SEBORRHEIC KERATOSES AND ACRAL VERRUCA VULGARIS

A 37-year-old man came to us with asymptomatic dark colored warty iesions of 3V2 years' duration. The lesions started on the dorsa of the feet and hands and progressively increased in size and number to cover more than 60% of these areas. Later, they spread to other parts of the body. There was no history of sudden loss of weight or appetite, change in bowel habits, or of major illness in the past. The patient had not taken any medication. A general and systemic examination of the patient revealed no abnormality. On dermatological examination, hyperpigmented well-defined, verrucous papules and plaques of varying sizes were seen on the extremities, almost covering the dorsa of the hands and feet (Figs. 1–3). Small flattopped hyperpigmented papules with a smooth surface and “stuck-on” appearance were present on the trunk (Fig. 4). The rest of the body had scattered hyperpigmented papules and plaques, up to 2 × 2 cm in size with a minimally verrucous surface. The patient also had a shiny appearance of the face, infiltration of the ear lobes, with mild ichthyosis of the limbs. Examination of the peripheral nerves revealed bilateral thickening without tenderness or sensory loss. Slit smears for acid-fast bacilli from the earlobe and normal skin showed a bacteriological index of 5+ and 2+, respectively. A diagnosis of lepromatous leprosy with extensive verruca vulgaris and seborrheic keratoses was made. Biopsies of the normal-looking skin, the flat truncal lesions, and the verrucous lesions on the extremities were taken. Histopathologic examination of the trunk lesions showed hyperkeratosis and acanthosis with interwoven tracts of basaloid cells and horn cysts, indicative of the acanthotic type of seborrheic keratosis (Fig. 5). Below the epidermis there was a clear zone of dermis. A foamy macrophage granuloma was seen in the deeper dermis; M. leprae with Fite-Faraco staining was demonstrated. On histopathologic examination the acral lesions showed hyperkeratosis, acanthosis, and papillomatosis. The rete ridges were elongated and bent inwards and typical vacuolated cells were seen in some areas, indicative of verruca vulgaris (Fig. 6). The biopsy from a lesion on the arm revealed seborrheic keratosis and verruca vulgaris in continuity along the epidermis with a foamy macrophage granuloma in the lower dermis (Fig. 7). Mycobacterium leprae were demonstrable in all the sections. Thus, the histopathology of the lesions confirmed a diagnosis of lepromatous leprosy with acral verruca vulgaris and truncal seborrheic keratosis. The patient was further investigated and baseline parameters including urine and stool examination, hemogram, blood sugar, and renal and hepatic function tests revealed no abnormality. Keeping in mind the sign of Leser-Trelat, the patient was also investigated for any focus of malignancy. Gastroscopy, x-ray of the chest, and other tests were normal. The Mantoux and blood serology for H(v were negative. The patient was started on antileprosy treatment according to the WHO Multidrug Regimen and was also given a course of levamisole. Minimal response was noted. Eighteen months later the patient returned to the hospital and a 50% regression of the acral lesions was seen. A few lesions were also cauterized by electrocautery and the response was good.