Plasmodium vivax: in vitro development of exoerythrocytic stages in squirrel monkey hepatocytes and inhibition by an anti-P. cynomolgi monoclonal antibody.
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Animals↗
Biomedical subjects
P Millet
Publications and source records attributed to P Millet.
Nutrient intake and vitamin status of healthy French vegetarians and nonvegetarians.
The status of thiamin, riboflavin, folate, and vitamins B-6, B-12, C, A, D, and E was investigated in 37 middle-aged and healthy French vegetarians by means of a dietary survey and biochemical studies. Values were compared with those of a group of nonvegetarians. Unsatisfactory intakes of vitamin B-6 were observed: vitamin B-6 intake as a percentage of the French Recommended Dietary Allowances was approximately 66% for vegetarians and approximately 58% for nonvegetarians. Vegetarians had a higher mean intake of thiamin, riboflavin, and vitamins C, A, D, and E than did nonvegetarians. Vegetarians did not have a higher risk rate for a biochemical vitamin deficiency of thiamin, riboflavin, folates, and vitamins B-6, C, A, and E than the nonvegetarians. The percentage of subjects assessed as abnormal by blood vitamin concentrations was higher in vegetarians for vitamin B-12 (serum vitamin B-12) and vitamin D, which indicated a higher risk for a deficiency of vitamins B-12 and D in this group.
Adult↗
In-vitro exoerythrocytic development of Plasmodium cynomolgi bastianellii: inhibitory activity of monoclonal antibodies against sporozoites of different P. cynomolgi strains and of P. knowlesi.
The inhibitory effect of anti-sporozoite monoclonal antibodies (MoAb) on the in-vitro development of liver stages of Plasmodium cynomolgi bastianellii (NIH strain) was evaluated using primary cultures of rhesus monkey hepatocytes. MoAbs against the circumsporozoite proteins of five strains of P. cynomolgi (NIH, London, Gombak, Ceylon, Berok), and of P. knowlesi (H strain) were used. Incubation of sporozoites of P. cynomolgi bastianellii with the anti-NIH strain MoAbs entirely prevented liver-stage development; MoAbs produced against the other four strains had no apparent activity. The anti-P. knowlesi MoAbs had a partially inhibitory effect on parasite development. These functional studies complement previous immunological studies on P. cynomolgi strain specificity, and confirm the cross-reactivity observed previously between sporozoites of P. cynomolgi bastianellii and P. knowlesi (H strain).
Animals↗
Localization of circumsporozoite antigen in exoerythrocytic schizonts of Plasmodium cynomolgi.
We used colloidal gold probes and post-embedding immunoelectron microscopy to localize circumsporozoite (CS) antigen in 5- and 8-day-old in vitro cultures of Plasmodium cynomolgi exoerythrocytic (EE) schizonts. Both small uninucleated and large multinucleated EE schizonts were found in 5-day-old cultures. A mouse monoclonal antibody to the repeat region of the P. cynomolgi CS protein densely labeled the plasma membrane and surface of 5-day-old EE schizonts as well as the surrounding parasitophorous vacuole membrane and space. Density of labeling decreased significantly as EE schizonts increased in size and maturity. Labeling of large, multinucleated 5-day-old schizonts was sparse and limited to the surface of EE schizonts and to small patches of electron dense material which were attached to the inner surface of the parasitophorous vacuole membrane. Mature 8-day-old EE schizonts with developing merozoites had little detectable labeling. CS antigen was not associated with internal structures within developing schizonts. Labeling was not observed in the host cell cytoplasm or on the surface of infected hepatocytes. These findings indicate that epitopes associated with the repeat region of the P. cynomolgi circumsporozoite protein are sequestered within infected host cells during EE development.
Animals↗
In vitro activity of antimalarial compounds on the exoerythrocytic stages of Plasmodium cynomolgi and P. knowlesi.
Primary cultures of Macaca mulatta hepatocytes infected with sporozoites of Plasmodium knowlesi, P. cynomolgi (Cambodian strain), and P. cynomolgi bastianellii were exposed in vitro to 7 antimalarial compounds. The number of exoerythrocytic schizonts present after 4-7 days of culture was used to assess the activity. With pyrimethamine, proguanil, cycloguanil, primaquine, and 2 of its analogues (WR242511 and WR238605), marked inhibition of schizont formation could be achieved at concentrations below those causing a cytotoxic effect on the host hepatocytes. Chloroquine had only minimal schizonticidal activity at a concentration that produced severe hepatocyte toxicity. This simian in vitro system provides a reliable model for screening antimalarial compounds and for investigating their effects on the hepatic stage of malaria parasites.
Animals↗
[Diabetes and the insulin pump: functional results after 5 consecutive years of permanent use].
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Adult↗
Enhancement of in vitro infectivity of simian malaria sporozoites to hepatocytes by centrifugation.
Sporozoites of Plasmodium cynomolgi, Plasmodium knowlesi, and Plasmodium coatneyi were deposited onto monolayers of hepatocytes from rhesus monkeys (Macaca mulatta). When sporozoites were centrifuged (1,600 g for 5 min), 4-13-fold more schizonts were observed than were found in noncentrifuged control cultures. Centrifugation of hepatocyte monolayers before adding sporozoites did not modify the number of parasites.
Animals↗
[Meleney's postoperative gangrene].
The authors report the case of a 40 years old man undergoing MOPP chemotherapy for stage III Bb type 2 Hodgkin's disease with immune depression. Six years later he developed two episodes of unilateral transient loss of vision and severe stenosis of the left common carotid artery was found leading to surgical reimplantation of the left subclavian artery. Quickly spreading cutaneous necrosis was observed 5 days after surgery on the scar and the irradiated area: Meleney's postoperative gangrene, an unusual and frequently fatal complication of unknown cause. The patient recovered in two months after wide excision of the necrosed tissues and a skin autograft.
Adult↗
Development of sodium and chloride transport across fetal and newborn rat stomach in vitro.
1. Unidirectional and net Na+ and Cl- fluxes were determined across isolated fetal rat stomach 19-21 days post-coitum, and across the stomach of newborn rats aged 5 or 12 days. 2. On fetal day 19, absorption of both Na+ and Cl- was greater than the short-circuit current, Isc (net Na+ flux, JnetNa = 4.7 +/- 1.0 and net Cl- flux, JnetCl = 5.4 +/- 1.4 mu equiv cm-2 h-1 vs. Isc = 0.9 +/- 0.1 mu equiv cm-2 h-1). Mucosal addition of 10 microM-amiloride did not significantly alter JnetNa, JnetCl, Isc or total conductance. 3. However, on fetal day 20, neutral absorption of NaCl was no longer observed but amiloride had inhibited electrogenic absorption of Na+, and significant active secretion of Cl- was observed (JnetCl = -1.3 +/- 0.6 mu equiv cm-2 h-1). On day 21 (i.e. 24 h before birth), values for JnetNa, JnetCl, and Isc were not different from those determined on adult gastric mucosa. 4. After birth, NaCl transport continued to exhibit its prenatal characteristics on day 5 but not on day 12, when Na+ and Cl- were both absorbed; on that day, JnetNa-Isc was equal to both JnetCl and to the amiloride-insensitive component of Isc, indicating that neutral NaCl absorption had resumed. 5. These data show that in rat stomach, NaCl transport differentiates on fetal day 20, when H+ secretion is first observed, and thereafter undergoes biphasic development. 6. The significant Cl- absorption observed on post-natal day 12 was concomitant with the inhibition of net H+ secretion.
Amiloride↗
In vitro cultivation of exoerythrocytic stages of the human malaria parasite Plasmodium malariae.
Exoerythrocytic stage parasites of Plasmodium malariae were obtained in vitro by inoculating primary cultures of hepatocytes from a chimpanzee (Pan troglodytes) and a monkey (Aotus lemurinus griseimembra) with sporozoites. Schizonts were observed in chimpanzee hepatocytes 8, 11, and 13 days after inoculation. Only 1 schizont was seen in Aotus hepatocytes at day 13. The morphology and development rates of P. malariae exoerythrocytic stages obtained in vitro were similar to those previously described in vivo.
Animals↗
Cultivation of exoerythrocytic stages of Plasmodium cynomolgi, P. knowlesi, P. coatneyi, and P. inui in Macaca mulatta hepatocytes.
Exoerythrocytic stage parasites of Plasmodium cynomolgi, P. knowlesi, P. coatneyi, and P. inui were cultured by inoculating primary cultures of hepatocytes from Macaca mulatta with sporozoites. Less than 1% of inoculated sporozoites survived. Morphology and size of the liver stages in all 4 species were similar to in vivo descriptions and the time required for in vitro maturation correlated well with prepatent periods described.
Animals↗
Photooxidation products of primaquine. Structure, antimalarial activity and hemolytic effects.
Photooxidation of primaquine (1) and 5-hydroxyprimaquine (5) afforded a blue dye for which o-quinone structure 4 was elaborated. Similar oxidation of N-ethoxyacetylprimaquine (10) afforded o-quinone 11. Tissue schizontocidal activity of 4 and 11, and bisquinolylmethine 3 prepared earlier, showed that none of them had noteworthy antimalarial activity, but all three produced methemoglobin.
Animals↗
Antimalarial activity and inhibition of monoamine oxidases A and B by exo-erythrocytic antimalarials. Optical isomers of primaquine, N-acylated congeners, primaquine metabolites and 5-phenoxy-substituted analogues.
When the terminal amino group in the side chain of primaquine was blocked with an ethoxyacetyl group shown in 2, or eliminated by oxidative deamination to carboxylic acid 3, the antimalarial effect was markedly reduced in a screening assay which measures tissue schizonticidal activity. The optical isomers 1A and 1B of primaquine had similar antimalarial potency to the racemic mixture but 1B appeared less toxic. The 5-phenoxy-substituted analogue 4, belonging to a new class of antimalarials, showed similar potency in the assays to either 1A or 1B but seemed less cytotoxic than (+/-)-primaquine. Compounds 1A and 1B were found to be competitive inhibitors of human monoamine oxidase (MAO) A and B (Ki range 103-225 microM), but 4 showed 10-30-fold greater competitive inhibition of MAO A (Ki = 6.8 microM) and 40-90-fold greater non-competitive inhibition of MAO B (Ki = 2.3 microM).
Animals↗
[In vitro cultivation of Plasmodium cynomolgi bastianelli in hepatocytes of the Macaca rhesus].
Primary cultures of Rhesus monkey were infected with sporozoites of P. c. bastianelli. Despite a high level of contamination, two schizonts were seen at days 6 and 11.
Animals↗
Ontogeny of rat gastric H+-K+-ATPase activity.
Gastric H+-K+-ATPase activity was examined in subcellular fractions (P1, 1,000 g; P2, 20,000 g; P3, 100,000 g) obtained from fundic mucosae of fetal, newborn, and adult rats. Depending on the tissue secretory state the distribution of this enzyme activity predominates in P3, i.e., resting adult, or in P2, i.e., stimulated adult, while total enzyme activity (P2 + P3) remains constant. Enzyme activity was detected as soon as day 19 of gestation and P2 + P3 reached 2.2 +/- 0.2 mumol Pi X mg prot-1 X h-1 at parturition. H+-K+-ATPase activity steadily decreased from 4.0 +/- 0.7 mumol Pi X mg prot-1 X h-1 on day 6 after birth to approximately 0 on day 12. This activity recovered as soon as day 13 (3.5 +/- 0.6 mumol Pi X mg prot-1 X h-1) and continued to rise slowly until adulthood. Incubation of subcellular fractions with 0.1 mM omeprazole resulted in a total loss of H+-K+-ATPase activity at all the stages of development examined. These studies of functional relationship during the development between gastric acid secretion and distribution of gastric H+-K+-ATPase activity among P2 and P3 fractions indicate that this last could be considered as an index of the secretory state of the parietal cell. This enzyme's pattern of development in P2 + P3, correlated with the one previously observed for stimulated H+ secretion in intact tissue, suggest that the H+-K+-ATPase is the limiting step in response to secretagogues during postnatal period.
Adenosine Triphosphatases↗
[Reflections on 851 open heart operations at the Institute of Cardiology in Abidjan].
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Adolescent↗
Dermatitis due to orthopaedic implants. A review of the literature and report of three cases.
The cases of three patients who had dermatosis that was caused by an orthopaedic implant are reported. The main clinical pattern was localized or generalized eczema or urticaria. The diagnostic criteria that have been proposed by various authors are reviewed. Removal of the implant did not always result in rapid disappearance of the dermatosis, presumably because a few particles of metal remained in the area of the implant.
Adult↗
[Infectious endocarditis surgically treated during the acute phase. 26 cases].
Twenty-six patients with infective endocarditis were operated upon during the active phase. The endocarditis was native in 24 cases and developed on cardiac valve prosthesis in 2 cases. Depending on the valve involved, the patients were divided into 3 groups: Ao (aortic valve, n = 13), M (mitral valve, n = 10) and T (tricuspid valve, n = 3). The overall mortality rate was 26% (group Ao 20%, group M 20%); death was due, in most cases, to haemodynamic failure. The duration of pre-operative antibiotic therapy, the functional stage of the disease and the cardiothoracic ratio had no influence on post-operative prognosis. In contrast, the presence of vegetations (notably on the aortic valve) at echocardiography and the pumping and aortic clamping times played a role in operative mortality. Twelve patients were followed up for a mean period of 23.9 months. They are all in stage I or II with significant decrease in cardiothoracic index. In Africa, where bacteriological facilities are often inadequate and cardiac valve diseases are diagnosed at a late stage, infective endocarditis is active in many cases. Under these conditions, early surgery is justified when heart failure is present and the infection is not clinically controlled.
Acute Disease↗