Use of delipidized antigens of Taenia solium metacestodes in IgG-ELISA for detection of neurocysticercosis.

The development of IgG-ELISA for detecting neurocysticercosis is aimed at the routine laboratory, and requires a particular antigen preparation, an acceptable number of serum samples to be tested (both homologous and heterologous) and patients with a diversity of helminthic infections to rule out cross-reactions. This study characterizes IgG-antibodies from cases of neurocysticercosis by assaying the sera against ether-delipidized antigens (5 microg/ml) prepared from metacestodes of Taenia solium. The test had a sensitivity of 90% and a specificity of 83%. IgG-antibodies from heterologous serum samples elicited a number of false positives (25/147) from six different helminthic infections, ie paragonimiasis, echinococcosis, opisthorchiasis, ascariasis, taeniasis and fascioliasis. In additional tests to detect antibody levels to these stage-related antigens, one of three serum samples from T. solium-infected cases gave negative at OD value of 0.187 while the others yielded 0.472 and 0.576. Conversely, assays of all serum samples from neurocysticercosis cases reacted against antigens from Echinococcus granulosus cystic fluid, Paragonimus heterotremus and Opisthorchis viverrini adult worms. In comparison, the antigens from these three species yielded higher mean OD values when assayed against the corresponding infected serum samples. Furthermore, neurocysticercosis cases yielded OD values that are separate and distinct from those of paragonimiasis cases.

Effects of antithrombin III and antivenom on procoagulant activity of Russell's viper venom in a whole blood model.

The procoagulant activities of Russell's viper venom were assessed in an in vitro whole blood model. Sequential samplings showed that the generation of fibrinopeptide A (FPA), a marker of thrombin activity, and platelet factor 4 (PF4), a marker of platelet activity, exhibited bi-phasic kinetics with an initial slow phase followed by a rapid phase of secretion. In the presence of Russell's viper venom, the generation of both FPA and PF4 was accelerated with the bi-phasic kinetics of PF4 being maintained while that of FPA completely disappeared. Administration of either antivenom (1,600 ng) or 10 IU antithrombin III (AT-III) had no antagonistic effect against the venom but combination of both resulted in a significant prolongation of both FPA and PF4 release (p < 0.05). High dose AT-III (20 IU) resulted in normalization of both FPA and PF4 kinetics and serial levels of both parameters were lower than those treated with the combined regimen, although these were not statistically significant. Unlike the untreated venom activated whole blood, there was no clot formation following treatment with either the combined regimen or high dose AT-III. The results of this study suggested that the effect of Russell's viper venom on the clotting cascade is more potent and direct than that on platelet activity. There were complementary effects between antivenom and AT-III is controlling of both FPA and PF4 release induced by the venom. Furthermore, in this in vitro experiment, AT-III alone when administered in a sufficient dose, abolished the procoagulant effects of Russell's viper venom.

Plasma concentrations of praziquantel during the therapy of neurocysticerosis with praziquantel, in the presence of antiepileptics and dexamethasone.

Plasma praziquantel concentrations were measured in 11 Thai patients with active neurocysticercosis (8 males and 3 females). Praziquantel (Biltricide 600 mg per tablet) was given at a daily dose of 45 mg/kg given in 3 divided doses for 15 consecutive days. All patients had significant improvement with resolution of symptoms and signs, and reduction of active lesions of cysticercosis shown by the brain computed tomographic scanning. After oral administration, the drug was rapidly absorbed from the gastrointestinal tract. There was substantial inter-individual variability in plasma concentrations of praziquantel. After the first dose, maximum plasma concentrations in the range of 42-540 ng/ml was attained at 30 minutes to 5 hours. In all cases, the drug almost totally disappeared from plasma within 8 hours; drug levels measured prior to the first doses on the following days showed undetectable levels. The area under the plasma concentration-time curves of praziquantel following the first dose were between 125 and 990 ng hour/ml. The results suggested that the unusual low plasma availability of the drug observed in this group of patients could be a consequence of pharmacokinetic drug interactions of the concomitant therapy with antiepileptic drugs and dexamethasone. Active metabolite(s), rather than praziquantel itself, may play a significant part in the therapy of neurocysticerosis.

Treatment of acute uncomplicated falciparum malaria with a short course of artesunate followed by mefloquine.

The clinical results of this study indicate that a half-dose regimen of artesunate followed by mefloquine produces an acceptable cure rate when compared to other commonly available drugs for treating acute uncomplicated falciparum malaria in Thailand. The 90% cure rate was comparable to the results with either a full dose of artesunate (600 mg over 5 days) or mefloquine (25 mg/kg in divided doses six hours apart) as well as the combination of quinine-tetracycline administered for seven days. This abbreviated regimen, however was less effective than the full dose regimen of both drugs previously reported.

The treatment of neurocysticercosis with praziquantel.

Twenty-five patients with cerebral cysticercosis admitted to the Bangkok Hospital for Tropical Diseases from March 1987 to November 1989 were studied. The patients had a mean age of 41 +/- 5 years with a mean body weight of 57 +/- 4 kgs. Male to female ratio was 1.5:1. Eight patients (32%) gave a history of having taeniasis with a mean duration of 3.6 years before having symptoms of cerebral cysticercosis. Six patients (24%) also had subcutaneous cysticercosis with a duration of 20 +/- 8 months. The important clinical symptoms were headache, focal seizure, epilepsy and dementia. Fourteen patients (56%) had headache, 12 patients (48%) had focal seizure and four patients (16%) had a mild degree of dementia. Baseline study included routine blood examination, biochemical tests, cerebrospinal fluid for routine examinations and immunological study. Biopsy of subcutaneous cysts, plain films of soft tissue and computerized tomography of brain. Praziquantel was given orally at a dosage of 45 mg/kg/day in 3 divided doses at 4-5 hour interval for 15 days. Patients who were taking anti-epileptic drugs before were permitted to continue their medications. The evaluation of results of treatment was done a year post treatment, ten patients (40%) were asymptomatic, 12 patients (48%) had much clinical improvement, their epileptic attack was controlled by 1-2 tablets of phenobarbital (1/2 g) at bedtime. Two patients (8%) had mild headache. One patient (4%) was not improved. Those patients with dementia were not improved.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of cysticercosis with praziquantel at the Bangkok Hospital for Tropical Diseases.

Twelve patients with cysticercosis including two cases of subcutaneous cysticercosis and ten cases of combined subcutaneous and, cerebral cysticercosis were treated with praziquantel 30 mg per kilogram of body weight daily in 3 divided doses for 10 days. To minimize possible reactions due to the death of parasites prednisolone 10 mg three times a day was also given in most cases. During treatment, an intense inflammatory reaction occurred as evidenced by increased intracranial pressure and convulsions. Histopathological findings studied at 2 weeks post treatment revealed lymphocytic and plasma cell infiltrations with destruction of the larvae. Clinical response was evident at one week post treatment, manifested by a significant decrease in size of the subcutaneous cysts which gradually disappeared at the end of three months. Radiology of soft tissues showed distortion of semicalcified cysts. Brain computerized tomography at 6 months post treatment showed disappearance of the cysts presumed to be due to death of cystercerci and marked reduction in numbers and size of other stages of cysts. Mild and transient side effects were observed in 25% of cases. Two patients (17%) had severe side effects and one (8%) had convulsions during treatment.

Low dose tinidazole in the treatment of amoebic liver abscess.

Thirty-six patients with uncomplicated amoebic liver abscess were treated with low dose tinidazole 1.2 g to 1.5 g in a single or divided doses, and aspiration of the abscess. No drug related toxicity was noted. All patients responded well and there was no relapse or treatment failure.

Radiological findings in pulmonary paragonimiasis heterotremus.

The routine chest roentgenogram of pulmonary paragonimiasis heterotremus were evaluated in 93 Thai and Laotian patients. They were 44 males and 49 females; the ages ranged from 12 to 79 years; the history of illness ranged from 4 months to 14 years and the egg output per day was 400 to 300,000. Twelve patients, 12.9% had normal roentgenologic films and 81 patients (87.1%) had abnormalities with 316 lesions; 22.2% had one lesion and 77.7% had multiple lesions. The common lesions were cystic formation, multiple or single and linear infiltration. Both lower lobes of the lungs and the left upper lobe were the common sites but any part of the lung may be affected. There were correlation between the duration of illness, number of eggs output per day and the extent of the lesions. The longer the duration of illness or the higher number of eggs output per day the more extensive lesions in the X-ray films have been observed.

Pulmonary paragonimiasis with expectoration of worms: a case report.

A 40-year old Thai farmer with pulmonary paragonimiasis was treated with Praziquantel 25 mg/kg body weight, three times after meals for one day. On follow-up treatment during hospitalization he coughed up 7 adult lung flukes. The worms were identified as Paragonimus heterotremus. This is probably the first case report to demonstrate adult mature Paragonimus coughed up from man.

The effect of prednisolone on red cell survival in patients with falciparum malaria.

Radioisotope red-cell survival studies were carried out in 20 patients with falciparum malaria following quinine therapy. The mean parasite clearance time of the patients receiving quinine sulfate was 49 hours and those of the patients receiving quinine sulfate and prednisolone was 46 hours. The red-cell survival was correlated with the initial hematocrit level in both groups but the daily dose of 40 mg prednisolone did not mitigate the red cell survival.