The mechanism behind the antileishmanial effect of zinc sulphate. II. Effects on the enzymes of the parasites

When used in vitro, zinc sulphate has a direct antileishmanial effect. To see if this effect involved the inhibition of the parasites' enzymes, extracts of the promastigotes and axenic amastigotes of Leishmania major (MHOM/IQ/93/MRC6) and L. tropica (MHOM/IQ/93/MRC2) were prepared. Zinc sulphate, at various concentrations, was then added to samples of these extracts before the activities, in the samples, of certain key enzymes of the Embden-Meyerhof pathway, hexose-monophosphate shunt and citric-acid cycle, and of two enzymes associated with virulence (protease and acid phosphatase), were determined. The zinc was found to inhibit every enzyme investigated, usually in a dose-dependent manner. Thus the direct antileishmanial effect of zinc may result, partially or entirely, from the inhibition of enzymes that are necessary for the parasites' carbohydrate metabolism and virulence.     

Medical ethics and tomorrow's physicians: an aspect of coverage in the formal curriculum

Medical ethics has created contentious issues and requires reforms in medical education such as renewed emphasis on formal instruction. The aim here was to review the current status of bioethics teaching in medical schools, determine Saudi students' perception of its coverage in the formal curriculum and make recommendations. Using a self-administered questionnaire in a cross-sectional study, undergraduate students' opinion about medical ethics coverage was obtained. Fourteen clinical departments and 201 students were studied. Only 46% of respondents were satisfied with the current coverage of ethical issues in the formal curriculum; 23% were unaware of the value of the subject. Students' approval rate was highest in Neurology and Psychiatry (70%). The study confirmed inadequate formal instruction on medical ethics in a developing country. Five recommendations are made. At admission, students' integrity and character should be assessed. Bioethics should be taught in clinical settings. In the Islamic world, medical curricula should include the Islamic code of medical ethics. Peers, nurses and patients should evaluate graduates' performance in ethics at the bedside. Evidence-based assessment and continuous quality improvement are required to maintain the requisite standard.     

Chemoprevention of Breast Cancer by Transdermal Delivery of α-Santalol through Breast Skin and Mammary Papilla (Nipple)

Purpose

Almost all breast cancers originate from epithelial cells lining the milk ducts in the breast. To this end, the study investigated the feasibility of localized transdermal delivery of α-santalol, a natural chemopreventive agent to the breast.

Methods

Different α-santalol formulations (cream, solution and microemulsion) were developed and the in vitro permeability was studied using excised animal (porcine and rat) and human breast skin/mammary papilla (nipple). The in vivo biodistribution and efficacy studies were conducted in female rats. A chemical carcinogenesis model of breast cancer was used for the efficacy studies.

Results

Phospholipid based α-santalol microemulsion showed the highest penetration through the nipple and breast skin. Delivery of α-santalol through the entire breast (breast skin and nipple) in vivo in rats resulted in significantly higher concentration in the mammary gland compared to transdermal delivery through the breast skin or nipple. There was no measurable α-santalol concentration in the blood. Transdermal delivery of α-santalol reduced the tumor incidence and tumor multiplicity. Furthermore, the tumor size was significantly reduced with α-santalol treatment.

Conclusions

The findings from this study demonstrate the feasibility of localized transdermal delivery of α-santalol for chemoprevention of breast cancer.

     

Electroconvulsive Therapy: The Struggles in the Decision-Making Process and the Aftermath of Treatment

The perceptions of patients and their family members about electroconvulsive therapy (ECT) are crucial to understanding the meaning attached to having ECT and the impact it has on quality of life. Thus, in this qualitative study, patients and their family members described their perceptions of having electroconvulsive therapy (ECT). The experience occurred in two distinct periods in the patient's life: making the decision to have ECT and the physical and emotional aftermath of treatment. One of the most important themes in the study was a need for patients and families to be better informed about the risks of ECT.