Generation of reactive oxygen species by blood monocytes during acute Plasmodium knowlesi infection in rhesus monkeys

The status and kinetics of monocyte activation during acute P. knowlesi infection was investigated by latex-induced, luminol-dependent chemiluminescence (CL) response. The contribution of various reactive oxygen species (ROS) to CL response was estimated before infection and at peak parasitaemia (day 7 post infection) by using scavengers of ROS (benzoate, catalase and superoxide dismutase). The chemiluminescence index (CLI) was not found to be significantly different from controls on day 2 postinfection, but was significantly higher on days 5 and 7 postinfection. Hydroxyl radical (OH.) production was considerably elevated, whereas superoxide anion (O2-.) and hydrogen peroxide (H2O2) production dropped following infection. These changes in generation of ROS are discussed in relation to the progression of parasitaemia to high levels, immunopathology and immunosuppression during acute P. knowlesi infection.     

Inverted papillomas that invade the orbit

We describe 10 patients with inverted papillomas (IPs), uncommon endophytic epithelial tumors that arose in the nose, paranasal sinuses, and lacrimal sac, that invaded the orbit; review the world literature on IP; and discuss treatment options. Patients ranged in age from 49 to 72 years (mean age, 62 years; median age, 66 years). Six patients were men and four were women. Presenting symptoms and signs included a medial canthal mass (n = 5), epiphora/lacrimal drainage obstruction (n = 3), inability to wear eyeglasses (n = 2), diplopia (n = 1), and painful dentures (n = 1). Histopathologic examination was performed in each patient and revealed all patients to have areas with malignant transformation: six patients with IPs that contained areas of squamous cell carcinoma and four with areas of transitional cell carcinoma in the tumor within the orbit. Eight of the patients with IPs had a recurrence after initial resection. In two patients, the IPs were completely excised and did not recur; yet, follow-up was short. Eight patients required orbital exenteration for local control of disease. Nevertheless, local spread of tumor through bone to brain occurred in three patients with orbital involvement. Indeed, IPs that invade the orbit have a high incidence of malignancy and are locally aggressive tumors. Treatment is difficult, and the recurrence rate is high. Early, wide excision of this aggressive tumor provides the best chance of cure.     

Chronic activation of protein kinase C in soleus muscles and other tissues of insulin-resistant type II diabetic Goto-Kakizaki (GK), obese/aged, and obese/Zucker rats. A mechanism for inhibiting glycogen synthesis

We examined the possibility that protein kinase C (PKC) is chronically activated and may contribute to impaired glycogen synthesis and insulin resistance in soleus muscles of hyperinsulinemic type II diabetic Goto-Kakizaki (GK) rats. Relative to nondiabetic controls, PKC enzyme activity and levels of immunoreactive PKC-alpha, beta, epsilon, and delta were increased in membrane fractions and decreased cytosolic fractions of GK soleus muscles. In addition, PKC-theta levels were decreased in both membrane and cytosol fractios, whereas PKC-zeta levels were not changed in either fraction in GK soleus muscles. These increases in membrane PKC (alpha, beta, epsilon, and delta) could not be accounted for by alterations in PKC mRNA or total PKC levels but were associated with increases in membrane diacylglycerol (DAG) and therefore appeared to reflect translocative activation of PKC. In evaluation of potential causes for persistent PKC activation, membrane PKC levels were decreased in soleus muscles of hyperglycemic streptozotocin (STZ)-induced diabetic rats; thus, a role for simple hyperglycemia as a cause of PKC activation in GK rats was not evident in the STZ model. In support of the possibility that hyperinsulinemia contributed to PKC activation in GK soleus muscles, we found that DAG levels were increased, and PKC was translocated, in soleus muscles of both (1) normoglycemic hyperinsulinemic obese/aged rats and (2) mildly hyperglycemic hyperinsulinemic obese/Zucker rats. In keeping with the possibility that PKC activation may contribute to impaired glycogen synthase activation in GK muscles, phorbol esters inhibited, and a PKC inhibitor, RO 31-8220, increased insulin effects on glycogen synthesis in soleus muscles incubated in vitro. Our findings suggested that: (1) hyperinsulinemia, as observed in type II diabetic GK rats and certain genetic and nongenetic forms of obesity in rats, is associated with persistent translocation and activation of PKC in soleus muscles, and (2) this persistent PKC activation may contribute to impaired glycogen synthesis and insulin resistance.     

The prevalence of atopy and hypersensitivity to latex in medical laboratory technologists

Members of the Alberta Society of Medical Laboratory Technologists were invited to take part in a study of sensitivity to latex gloves. A total of 230 persons volunteered; 108 (47%) had no problems with gloves, and 122 (53%) reacted to latex gloves. A history was obtained regarding atopy, smoking, years in laboratory medicine, and the nature of the problem with latex gloves. Serum was assayed for the total IgE level and the presence of IgE with specificity to common inhalant allergens and to latex. The affected group had an increased population of subjects with an atopic history and a higher incidence of a raised IgE level and a positive screen for inhalant allergens. In the affected group, there was no relationship between the total IgE level and severity of skin reaction. However, smoking was related to severity of reaction and was more common in the groups with a more severe reaction. Three subjects were positive for IgE specific for latex; there were no other data distinguishing them from latex-negative subjects.     

American Heart Association Report on the Public Access Defibrillation Conference, December 8-10, 1994. American Heart Association Taskforce on Automatic External Defibrillation

Experimental conditions (pH 6.5, 24 h reaction, peptide:biotin ratio 1:5) were defined for preferential incorporation of the biotin molecule in the N-terminal alpha-amino group of peptides. This strategy could be helpful in numerous applications when an entire peptide chain must remain accessible for antibody or receptor binding. We illustrate this advantage in a solid-phase enzyme immunoassay designed to detect antibodies specific for bovine beta-lactoglobulin present in rabbit or human sera. This test involves synthetic peptides biotinylated in different positions and immobilized on a solid phase. The use of biotin/streptavidin interactions permitted more efficient detection of specific anti-peptide antibodies than solid phases prepared using conventional passive-adsorption techniques. The highest levels of antibody binding were measured when biotinylation occurred at the N-terminal extremity of immobilized peptides.     

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.