Subcellular localization of hydrogen peroxide production in human polymorphonuclear leukocytes stimulated with lectins, phorbol myristate acetate, and digitonin: an electron microscopic study using CeCl3

The ultrastructural H2O2-producing site in human polymorphonuclear leukocytes (PMN) stimulated with soluble stimuli was studied using a CeCl3-technique. CeLlular aggregation and formation of small vacuoles were observed when PMN were stimulated with 100 microgram/ml concanavalin-A, 1 mg/ml phytohemagglutinin, or 100 microgram/ml wheat germ agglutinin for 10 min at 37 degrees C. Electron-dense deposits formed from the reaction of H2O2 and CeCl3 were observed on the contact surface of the plasma membrane of aggregated PMN stimulated with lectins. Treatment with 5 microgram/ml cytochalasin-B before lectin- stimulation induced an enhanced formation of vacuoles, degranuLation, rounding of the contour, cellular aggregation, and enhancement of the deposits. Phorbol myristate acetate (PMA; 100 ng/ml) induced strong leukocyte aggregation, the formation of multiple huge vacuoles, degranulation, and H2O2 production at almost all of the contact surface between adjoining PMN and between PMN and erythrocytes, mononuclear cells, or thrombocytes. In PMN stimulated with digitonin (B microgram/ml), vacuolar formation, degranulation, multiple projections on the surface, and H2O2 production on the whole surface membrane were demonstrated. It is shown that cellular aggregation and cell-to-cell contact have an important role in the induction of O2- production induced by lectins or PMA and that O2- production induced by the detergent is not dependent on leukocyte aggregation.     

Utilization of traditional healers for treatment of malaria among female residents in Makurdi city and its environs

ObjectiveTo ascertain the role of traditional healers in malaria treatment and its impact on control of the disease.MethodsThe study was cross-sectional in nature. Test-run structured and semi-structured questionnaires were either interviewer or self administered to adult women aged 18 years old and above. House holds were selected using systematic random sampling methods. Information such as age, educational level, marital status, occupation and methods of malaria treatment were obtained. Focused group discussions about beliefs and perceptions on utilization of traditional healers and in depth discussions on treatment and control of malaria were also carried out.ResultsOf the 2 075 respondents studied, 49.7% (n=1 031) utilized traditional healers for treatment of malaria, including 16.7% (n=172) utilizing traditional healers strictly while 83.3% (n=859) combining it with other treatment methods such as hospital/clinic, pharmacy/chemist shop, herbs or spiritual healing. The major contributors to utilization of traditional healers were: illiteracy and ignorance, poverty, unemployment/underemployment and slow pace of the comprehensive package implementation of the “roll back malaria” (RBM) programme initiate in the community.ConclusionsHealth education should be intensified while adequate facilities put in place to commence home management of malaria and probable free distribution of the artemisinin-based combination therapy (ACT).     

Instructions to authors

We investigated the effect of glucose and glucose polymer ingestion on plasma arginine vasopressin (pAVP) levels, on plasma osmolality (p-osm), and on performance during two prolonged endurance events. The study subjects were 37 Finnish elite endurance athletes, of whom 18 were orienteers and 19 cross-country skiers. Plasma AVP increased in both combined glucose and glucose polymer groups, but the increase in the glucose polymer group was significantly smaller (P 0.001) than that in the glucose group. A significant change in p-osm caused a significant change in pAVP and vice versa. Both the orienteers and the skiers on glucose polymer tended to have more success in the competition; the orienteers on glucose polymer ran the last third of the competition significantly faster than those on glucose (P 0.05). It is suggested, in the light of the smaller pAVP response, that after glucose polymer ingestion the physical stress in prolonged endurance exercise is smaller than after ingestion of glucose.     

Reduction of lymphocytic β-adrenoceptor level in chronic alcoholics and rapid reversal after ethanol withdrawal

Plasma catecholamine levels, lymphocytic beta-adrenoceptor densities and lymphocytic cAMP production were studied in 10 male subjects attending a withdrawal clinic after prolonged alcohol abuse. On admission the mean beta-adrenoceptor density was 29 +/- 9 fmol mg-1 protein (about 60% of the mean level of healthy control subjects, P less than 0.002). The following day a significant elevation of the beta-adrenoceptor level up to 46 +/- 19 fmol mg-1 protein (P less than 0.05) took place. This was accompanied by a parallel activation of the beta-adrenoceptor-mediated cAMP production of the lymphocytes. No major changes in beta-adrenoceptor levels or cAMP production took place during the next 7 days. Plasma catecholamine levels were elevated at arrival and decreased steadily during the withdrawal period. In conclusion, chronic alcoholism is associated with a reduction of lymphocytic beta-adrenoceptor density and functioning, which is followed by a rapid reversal during abrupt ethanol withdrawal. Thus an accelerated responsiveness to catecholamines may occur during the first ethanol-free day of chronic alcoholics.     

Immunoelectron microscopic findings in oral mucosa of patients with dermatitis herpetiformis and linear IgA disease

Abstract – Two patients with dermatitis herpetiformis and one with linear IgA disease were examined. Two of the patients had oral lesions and all three showed IgA deposits detected by direct immunofluorescence in apparently normal buccal mucosa. To localize the target structures for IgA deposition, biopsy specimens were taken from normal appearing buccal mucosa for immunoelectron microscopy. The patients with dermatitis herpetiformis had distinct IgA deposits in the upper connective tissue. These were often associated with elastic fibers and occasionally also with capillary walls. In contrast, the patient with linear IgA disease had IgA deposition at the subbasal lamina. Though the clinical expressions may be similar the present immunoelectron microscopic fmdings in oral mucosa clearly differentiate dermatitis herpetiformis from linear IgA disease.     

Intermittent pneumatic compression treatment for post-thrombotic leg ulcers

In an open clinical, trial three patients suffering from persistent post-thromhotic leg ulcers and five patients suffering from recurrent post-thromhotic leg-ulcers were treated by intermittent pneumatic compression therapy. For this purpose we used a novel device which produces both a sequential and graded pressure wave on the lower leg. Compared with previous conservative treatment only, intermittent compression treatment, together with conservative treatment, was found to shorten the ulcer healing time markedly. All the persistent ulcers which had not healed during the conservative treatment period healed during the intermittent compression treatment period. Skin oxygen tension, measured during the first occasion of compression treatment, was shown to increase. The healing rates seemed to correlate with decreasing leg swelling.     

Proteolytic Enzymes and Plasminogen Activator in Melanoma

Proteolytic activities were measured in extracts of human skin melanoma, lymphatic metastasis and in nonmalignant naevi by using various proteinase substrates as well as plasminogen activator assay. pH-optima for hydrolysis of various proteinase substrates by these tumors were found to be essentially the same as in healthy human skin. Melanoma extracts were found to especially readily hydrolyze N-alpha-benzoyl-DL-arginine beta-naphthylamine (BANA) at pH 5.8 in the presence of 1 mmol/l dithiothreitol and EDTA (cathepsin B1-like enzyme) as well as histones and p-tosyl-L-arginine methyl ester (TAME) at pH 7.5, and showed increased capacity to activate plasminogen when compared to nonmalignant naevus. The possible role of proteinases in malignant melanoma is discussed.     

T-type Ca2+ channels contribute to IBMX/forskolin- and K(+)-induced Ca(2+) transients in porcine olfactory receptor neurons

T-type Ca(2+) channels are low-voltage-activated Ca(2+) channels that control Ca(2+) entry in excitable cells during small depolarization above resting potentials. Using Ca(2+) imaging with a laser scanning confocal microscope we investigated the involvement of T-type Ca(2+) channels in IBMX/forskolin- and sparingly elevated extracellular K(+)-induced Ca(2+) transients in freshly isolated porcine olfactory receptor neurons (ORNs). In the presence of mibefradil (10microM) or Ni(2+) (100microM), the selective T-type Ca(2+) channel inhibitors, IBMX/forskolin-induced Ca(2+) transients in the soma were either strongly (>60%) inhibited or abolished completely. However, the Ca(2+) transients in the knob were only partially (<60%) inhibited. Ca(2+) transients induced by 30mM K(+) were also partially ( approximately 60%) inhibited at both the knob and soma. Furthermore, ORNs responded to as little as a 2.5mM increase in the extracellular K(+) concentration (7.5mM K(+)), and such responses were completely inhibited by mibefradil or Ni(2+). These results reveal functional expression of T-type Ca(2+) channels in porcine ORNs, and suggest a role for these channels in the spread Ca(2+) transients from the knob to the soma during activation of the cAMP cascade following odorant binding to G-protein-coupled receptors on the cilia/knob of ORNs.     

Density and functioning of human lymphocytic β-adrenergic receptors during prolonged physical exercise

In order to study the regulation of β-adrenergic receptor number and function in response to prolonged physical effort, lymphocytic β-adrenoceptor density (determined by (-)[¹²⁵I]iodocyanopindolol binding), lymphocytic basal and isoproterenol-stimulated cyclic AMP (cAMP) production and concentrations of plasma catecholamines were measured before and during 3 h running exercise in eight healthy volunteers. A significant (P < 0.01) increase of the lymphocytic β-adrenoceptor density from 45±4 to 81 ± 9 fmol mg^-1 protein (mean ± SEM) took place during the first hour of exercise. As the exercise was continued for up to 2.1–3 h, the receptor densities did not change significantly any more and remained elevated (72 ± 9 fmol mg^-1 protein) in comparison to the resting levels (P < 0.02). The isoproterenol-stimulated cAMP production of the lymphocytes increased during the first hour of running from 190 ± 36 to 269 ± 56 pmol mg^-1 protein (P < 0.01) and returned to the resting level at the end of the exercise (182 ± 38 pmol mg^-1 protein). The mean levels of plasma catecholamines increased ? sixfold during the first hour of exercise and remained elevated until the end of the running. This study demonstrates that the β-adrenergic receptor system is activated in lymphocytes during prolonged aerobic physical exercise. This activated state becomes, however, attenuated within 2–3 h of exercise as indicated by a diminishing ability of β-adrenoceptors to mediate catecholamine-induced cAMP production.