Sun Protective Clothing and Sun Avoidance: The Most Critical Components of Photoprotection in Patients With Melanoma.

BACKGROUND: Ultraviolet radiation is the main modifiable risk factor for melanoma which can be reduced by avoiding excess sun exposure. OBJECTIVE: We sought to explore (1) sun protective practices, (2) effectiveness of these sun protective practices, and (3) vitamin D supplementation in patients with melanoma. METHODS: Using the National Health Interview Survey, the authors conducted a cross-sectional analysis to investigate sun protective behaviors and sunburns among adults with melanoma compared with those without skin cancer. We calculated adjusted odds ratio (aOR), 95% confidence interval (95% CI), and p-values using logistic regression. RESULTS: Patients with melanoma reported increased use of sun avoidance, shade, sunscreen, long sleeves, and hats, but had similar sunburn rates compared with those without skin cancer. Only sun avoidance and long sleeves were associated with decreased odds of sunburn. Patients with melanoma also reported decreased vitamin D supplementation. CONCLUSION: Although it is reassuring that patients with melanoma practice sun protective behaviors, this does not always translate into reduced sunburns. Physicians should emphasize the importance of photoprotection, especially sun avoidance and sun protective clothing, to reduce future melanoma risk.

Cytotoxic action of cis-unsaturated fatty acids on human cervical carcinoma (HeLa) cells in vitro.

The effect of n-3 and n-6 fatty acids (FAs) on the growth of human cervical carcinoma (HeLa) cells was studied. Of all the FAs tested, docosahexaenoic acid (DHA, 22:6 n-3) and eicosapentaenoic acid (EPA, 20:5 n-3) were found to be the most potent in their cytotoxic action on HeLa cells and the potency of various fatty acids with regard to their cytotoxic action was as follows: DHA > EPA > dihomo-gamma-linolenic acid (DGLA) = gamma-linolenic acid (GLA) > linoleic acid (LA) > arachidonic acid (AA) > alpha-linolenic acid (ALA). The cycloxygenase inhibitor indomethacin, the lipoxygenase inhibitor nordihydroguaretic acid (NDGA), the antioxidants vitamin E, butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT), the superoxide anion quencher superoxide dismutase (SOD), the hydroxyl and hydrogen peroxide quenchers mannitol and catalase, respectively, and the calmodulin antagonists trifluoperazine (TFP) and chlorpromazine (CPZ) could all block the cytotoxic action of GLA, which was used as a representative cytotoxic FA, on HeLa cells. On the other hand, copper and iron salts and buthionine sulfoxamine, a glutathione (GSH) depletor, potentiated the cytotoxic action of suboptimal doses of GLA. GLA-induced radical generation and lipid peroxidation in HeLa cells could be blocked by indomethacin, NDGA and calmodulin antagonists. The cytotoxic action of cis-unsaturated fatty acids (c-UFAs) is not dependent on the alteration in the protein kinase C levels since no alteration in the diacylglycerol levels was observed. Hydroxy and hydroperoxy products of GLA were found to be toxic to HeLa cells, whereas prostaglandin (PG)E1, PGF2 alpha, and prostacyclin stimulated cell growth. From these results, it is evident that radicals are the modulators of the cytotoxic action of c-UFAs, that their formation is a calmodulin-dependent process, and that lipoxygenase products may mediate the tumoricidal action of FAs.

Randomized trial of drainage of colorectal anastomosis.

A prospective randomized trial was carried out to determine whether use of a high-pressure closed-suction intraperitoneal drain was associated with a reduction in morbidity rate after colorectal resection and to examine the influence of drainage on postoperative fluid collections. A consecutive series of 148 patients who underwent colonic or colorectal resection were randomized to receive no drain (n = 51) or a high-pressure closed-suction drain for either 3 (n = 47) or 7 (n = 47) days. Three patients were excluded. All patients underwent abdominal ultrasonography on days 3 and 7 and those undergoing left-sided colorectal resection (n = 96) received a water-soluble contrast enema on day 7. The three groups of patients were similar in age, sex, diagnosis and the numbers of sutured and stapled anastomoses. The presence of a drain did not influence the postoperative morbidity or mortality rate. If the anastomosis leaked, neither faeces nor pus emerged from the drain. Ultrasonographic detection of a fluid collection was of no value: such collections bore no relationship to radiological or clinical leaks or the postoperative course. Routine use of a high-pressure suction drain after colorectal resection appears to be unnecessary.

Effect of essential fatty acids on tumor cells.

An earlier study showed that essential fatty acids and their metabolites can kill tumor cells in vitro. This tumoricidal action can be correlated to an increase in generation of free radicals in the tumor cells. Evening primrose oil (EPO) is a rich source of linoleic acid and gamma-linolenic acid. We report that EPO can kill tumor cells both in vitro and in vivo. This tumoricidal action of EPO was associated with a threefold increase in superoxide generation. One of the factors that is capable of interfering with the cytotoxic action of fatty acids appears to be the protein content of the medium. Fatty acids can bind to protein and thus prevent their cytotoxic action.

Action of praziquantel on calcium transport in Hymenolepis diminuta.

Effect of praziquantel on inward and outward Ca++ fluxes was investigated in Hymenolepis diminuta in glucose supplemented balanced electrolyte solution and under conditions of glucose/Mg++ deficiency. The 45Ca++ uptake in freshly isolated worms presented, generally, a biphasic kinetics. This comprised of an initial fast uptake phase, followed by a continued slower influx. The initial fast kinetics showed insensitivity to or slight stimulation by praziquantel depending on its concentration, and such stimulatory action was particularly prominent under Mg++ deficient condition (P less than 0.01). The subsequent slower 45Ca++ uptake was, however, markedly inhibited by the drug under both these conditions (P less than 0.01). Glucose starvation of the worms resulted in abolition of the fast 45Ca++ influx phase and uniform inhibition by the praziquantel without any indication of initial stimulatory effect (P less than 0.01). The extrusion of 45Ca++ from the label preloaded worms was stimulated by praziquantel under all the conditions investigated (P less than 0.01).