One-year experience with subdermal contraceptive implants in the United States

Women who received Norplant contraceptive implants from any of fifteen clinical settings in southeast Texas, U.S.A., were followed for one year to determine their reactions to the method. Of 1,385 who enrolled to receive Norplant implants, 1,253 had implants inserted. Side effects were reported by 78% of those receiving implants and 70% described changes in bleeding patterns. Spotting or irregular bleeding, weight gain and headaches were the conditions reported most frequently. Nine pregnancies were reported during the study period. Six of these, however, existed before the implants were inserted. At the one year anniversary, 143 of women receiving implants had had them removed. Those who discontinued method use were less satisfied, reported more side effects and were more likely to have planned to have another child, thus using the method for spacing, or to have had a change in their marital status while they were using the contraceptive. Providers should counsel patients to focus attention on plans for the future in selecting their contraceptive method. In addition, we recommend, as does the product's distributor, that providers confirm that patients are not pregnant prior to inserting implants.     

Linear porokeratosis presenting as erosions in the newborn period

The classic appearance of porokeratosis is characterized by a hyperkeratotic annular rim that expands peripherally, leaving an atrophic center. Linear porokeratosis is a variant with collections of such lesions arranged in a linear fashion, usually corresponding to a dermatome or Blaschko's lines. Ulcerations have rarely been reported in patients with porokeratosis. We report an unusual case of linear porokeratosis at birth, with erosions and ulcerations of the face and lower extremity, that eluded diagnosis for nearly a year. Porokeratosis should be considered in the differential diagnosis of erosions in the newborn period.     

Experimental studies on the mechanisms of tiaprofenic acid photosensitization

Red blood cell lysis and histidine degradation, photosensitized by tiaprofenic acid (TIA), were investigated. Photohaemolysis was markedly enhanced in oxygenated solutions, but was also intense in the presence of nitrogen. Photohaemolysis was inhibited by butylated hydroxyanisole and reduced glutathione, but was unaffected by sodium azide, superoxide dismutase and mannitol. The TIA-induced photo-oxidation of histidine was greatly enhanced in the presence of oxygen and almost completely inhibited in solutions bubbled with nitrogen. Sodium azide, butylated hydroxyanisole and reduced glutathione inhibited the photodegradation of histidine. Phototoxicity to histidine was unaffected by mannitol and superoxide dismutase. The overall results suggest that molecular mechanisms involving free radicals and singlet oxygen are responsible for TIA-photosensitized reactions. These two in vitro models (photohaemolysis and histidine degradation) represent different mechanisms of phototoxicity, but complement one another in the investigation of potential phototoxic substances.     

Gastric emptying in Mexican Americans compared to non-Hispanic whites

Mexican Americans, a group at high risk for type II diabetes mellitus, have higher postprandial insulin and glucose levels when compared to non-Hispanic whites. A rapid rate of gastric emptying contributes to an increased rate of nutrient absorption and subsequent greater elevation of postprandial glucose and insulin levels. A more rapid rate of gastric emptying and hyperinsulinemia have been observed in patients with recently diagnosed type II diabetes mellitus. In this study, we examined whether Mexican Americans have a more rapid rate of gastric emptying than non-Hispanic whites. Gastric emptying studies were performed on 32 nondiabetic Mexican Americans and on 31 nondiabetic non-Hispanic whites. The rate of gastric emptying following a liquid glucose meal was measured. Serum insulin, plasma glucose, and GIP levels were measured in fasting and postprandial blood samples collected at 15-min intervals for 2 hr. Adjusting for age, body mass index, and gender, the gastric half-emptying time of a glucose meal was significantly (P < 0.05) more rapid for the Mexican American subjects (56.5 +/- 3.4 min) compared to the non-Hispanic white subjects (66.4 +/- 3.5 min). Nondiabetic Mexican Americans empty a liquid glucose meal more rapidly from their stomachs than nondiabetic non-Hispanic whites. Rapid gastric emptying is associated with hyperinsulinemia as a normal physiologic response to increased nutrient availability. The rapid gastric emptying observed in nondiabetic Mexican Americans is associated with hyperinsulinemia and could be a contributing factor for the increased risk of obesity and type II diabetes in this population.     

Thrombin receptor activating peptide does not stimulate platelet procoagulant activity

Platelets after challenge with alpha-thrombin alone, collagen alone or thrombin/collagen mixture were observed to increase the rate of activation of prothrombin by factor Xa in the presence of factor Va and calcium ion (platelet procoagulant activity) by a maximum of 25, 45 and 110 fold, respectively. The increase in platelet procoagulant activity due to these agonists has been described previously and arises from increased expression of phosphatidylserine on the platelet surface. When platelets were treated with the thrombin receptor activating peptide (TRAP) (SFLLRNPNDKYEPK), alone or in the presence of collagen or thrombin, no change in platelet procoagulant activity was observed at concentrations of TRAP sufficient to cause increased intracellular calcium levels and protein phosphorylation in a manner similar to that of thrombin. In addition, no increase in platelet procoagulant activity was seen upon treatment with TRAP in the presence of inactivated thrombin (PPACK-thrombin). These results suggest that the thrombin-mediated increase in procoagulant activity may be due to activation of a thrombin receptor distinct from the recently cloned G-protein-coupled receptor, or to other proteolytic events on the platelet surface.     

Oxygen uptake and cardiac output during progressive and constant load work in patients after acute myocardial infarction

PURPOSE: Simultaneously measured oxygen uptake (VO2) and Doppler echocardiography could verify if an alteration in the VO2 response to progressive and constant load work is due to reduced cardiac output. METHODS: The study group consisted of nine patients after acute myocardial infarction (MI), five age-matched healthy subjects (HE), and five young well-trained subjects (WT). Each subject performed a progressive exercise test and two bouts of constant load work at power outputs equated to 10% below (W1) and 10% above (W2) their ventilatory thresholds. VO2 and cardiac output were measured continuously and simultaneously during the tests. RESULTS: VO2 was significantly reduced for the MI group during the initial stages of the progressive exercise test (P < .02) and remained lower throughout the entire test. During the first 60 seconds of constant load work (W2), VO2 was lower for MI (P < .05). At steady state exercise during W2, cardiac output was significantly less for MI (P < .05). VO2 for the MI group was more reliant on cardiac output during lower power outputs and differences in the arterial and venous O2 content (a-VO2 difference) during greater power outputs. CONCLUSIONS: Cardiac rehabilitation programs must be aware of this delayed VO2 and cardiac output response when setting training workloads or selecting the magnitude of the workload increments during progressive exercise tests.