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Biomedical subjects

A Verster

Publications and source records attributed to A Verster.

At least 19 recordsLinked to original sources

Oral naltrexone maintenance treatment for opioid dependence.

BACKGROUND: Research on the clinical application of oral naltrexone agrees on several things. From a pharmacological perspective, naltrexone works. From an applied perspective, however, this medication is not used since the medication compliance and the retention rates are very poor. OBJECTIVES: To evaluate the effects of naltrexone maintenance treatment versus placebo or other treatments in preventing relapse in opioid addicts after detoxification. SEARCH STRATEGY: We searched the Cochrane Drugs and Alcohol Group Register of Trials (January 2005), Cochrane Central Register of Controlled Trials (CENTRAL - The Cochrane Library Issue 1, 2005), MEDLINE (1973-first year of naltrexone use in humans- January 2005), EMBASE (1974- January 2005), PsycINFO (OVID-January 1985 to January 2004). We inspected reference lists of relevant articles and we contacted pharmaceutical producers of naltrexone, authors and other Cochrane review groups. SELECTION CRITERIA: All randomised and controlled clinical trials which focus on the use of naltrexone maintenance treatment versus placebo, or other treatments to reach sustained abstinence from opiate drugs DATA COLLECTION AND ANALYSIS: Three reviewers independently assessed studies for inclusion and extracted data. One reviewer carried out the qualitative assessments of the methodology of eligible studies using validated checklists. MAIN RESULTS: Ten studies, 696 participants, met the criteria for inclusion in this review. Only two studies described an adequate allocation concealment. The results show that naltrexone maintenance therapy alone or associated with psychosocial therapy is more efficacious that placebo alone or associated with psychosocial therapy in limiting the use of heroin during the treatment (RR 0,72 95% confidence interval 0.58 to 0.90). If we consider only the studies comparing naltrexone with placebo, the difference do not reach the statistical significancy, RR 0.79 (95%CI 0.59 to 1.06). With respect to the number of participants re incarcerated during the study period, the naltrexone associated with psychosocial therapy is more effective than the psychosocial treatment alone; RR 0.50 (95%CI 0.27 to 0.91). No statistically significant benefit was shown in terms of retention in treatment, side effects or relapse results at follow-up for any of the considered comparisons. AUTHORS' CONCLUSIONS: Unfortunately the studies did not provide an objective evaluation of naltrexone treatment in the field of opioid dependence. The conclusions are also limited due to the heterogeneity of the trials both in the interventions and in the assessment of outcomes.

Administration, Oral↗

Food fortification: good to have or need to have?

Only very small quantities of vitamins and minerals are needed for human health but deficiencies can have disproportionately large, often life-threatening, effects. Micronutrient deficiencies lead to a vicious cycle of malnutrition and infection in poorly nourished populations. Fortification of staple foods is the cheapest, most efficient and most effective way to supply large populations with essential micronutrients. This paper reviews the case for fortification of flour supplies with iron and folic acid and concludes that it is the best way to provide daily doses of these nutrients to populations in developing countries, especially for women of child-bearing age.

Adult↗

Prevalence of HIV infection and risk behaviour among street prostitutes in Rome, 1997-1998.

A cross-sectional survey was carried out between April 1997 and February 1998 among street prostitutes in Rome. The study population (n = 142) consisted of 102 women and 40 transsexuals: 20% from Western Europe, 38% Eastern Europe, 23% Latin America and 17% Africa. Two-thirds of the population had more than 20 clients during the last week and most respondents (95%) reported always using condoms with clients. Eight per cent of the women and 2% of the transsexuals report a history of injecting drug use. Only 38% of the women with a stable partner reported use of contraceptives and 33% of them had undergone a voluntary abortion during the last year. Only 38% of the women had been checked for STDs during the last year, compared with 80% of the transsexuals. The HIV-prevalence was 6% among the women and 20% among the transsexuals. Four out of the six positive women and one of the positive transsexuals had a history of injecting drug use. Five out of the six HIV-positive women were Italian. Transsexual prostitutes seem to pay more attention to their medical wellbeing compared with females who rarely go for medical check-ups and only a minority uses efficient contraceptive methods.

Adult↗

Naltrexone maintenance treatment for opioid dependence.

BACKGROUND: Despite widespread use of naltrexone maintenance in many countries for more than ten years now (e.g., USA since 1984, UK since 1988) a sound documentation of the research on this drug is still missing. OBJECTIVES: To evaluate the effects of naltrexone maintenance treatment in preventing relapse in opioid addicts after detoxification. SEARCH STRATEGY: We searched MEDLINE, EMBASE, CCTR and handsearched the "Bolletino per le Farmacodipendenze e l'Alcolismo"; contact was sought with pharmaceutical producers of naltrexone, with authors and other CRGs; references of obtained studies. Trials were reliably identified and data extracted. Date of most recent searches: June 1998. SELECTION CRITERIA: All studies controlled for naltrexone; treatment of heroin addicts after detoxification with naltrexone. Studies were classified into three categories (high, moderate or low risk of bias) according to their methodological quality. DATA COLLECTION AND ANALYSIS: Reviewers evaluated data independently and analysed outcome measures taking into consideration adherence to and success of the study intervention. Data was extracted and analysed stratifying for the three categories of study quality. Where possible, meta-analysis was performed. MAIN RESULTS: Eleven studies were included in this review, and not all of them were randomised. Meta-analysis could be done to a low degree only, because the studies and their outcomes were very heterogeneous. The result of this quantitative analysis was statistically poor, and so was the methodological quality of the included studies. REVIEWER'S CONCLUSIONS: The available trials do not allow a final evaluation of naltrexone maintenance treatment yet. A trend in favour of treatment with naltrexone was observed for certain target groups, as described in the literature before. A well-done clinical trial is needed in order to get better evidence as soon as possible.

Humans↗

Duration of treatment with vitamin K antagonists in symptomatic venous thromboembolism.

BACKGROUND: Currently the most frequently used secondary treatment for patients with venous thromboembolism are vitamin K antagonists targeted at an INR of 2.5 (range 2.0 - 3.0). However, based on the continuing risk of bleeding and uncertainty regarding the risk of recurrent venous thromboembolism, there is discussion on the proper duration of treatment with vitamin K antagonists for these patients. Recently, several studies were published in which the risk and benefits of different durations of oral anticoagulants were compared in patients with venous thromboembolism. OBJECTIVES: The objective of this review was to evaluate efficacy and safety of different durations of treatment with vitamin K antagonists in patients with symptomatic venous thromboembolism. SEARCH STRATEGY: The reviewers sought publications through computerized searches of MEDLINE and EMBASE, and by hand-searching relevant journals, using the search strategy described by the Cochrane Review Group on Peripheral Vascular Diseases. They also contacted colleagues. SELECTION CRITERIA: Randomized controlled clinical trials comparing different durations of treatment with vitamin K antagonists in patients with symptomatic venous thromboembolism. DATA COLLECTION AND ANALYSIS: Two reviewers extracted the data and assessed the quality of the trials independently. MAIN RESULTS: Four studies with a total of exactly 1500 patients were included. A consistent reduction for the risk of recurrent events was observed during prolonged treatment with vitamin K antagonists (OR 0.15; 95% CI [0.10 - 0.23]) independent of the period elapsed since the index thrombotic event. A 'rebound' phenomenon, i.e. an excess of recurrences shortly after cessation of the prolonged treatment was not observed (OR 1.11; 95% CI [0.71 - 1.75]). In addition, a substantial increase in bleeding complications was found during the entire period after randomization (OR 7.75; 95% CI [1.08 - 55.57]). REVIEWER'S CONCLUSIONS: In conclusion this meta-analysis shows that treatment with vitamin K antagonists reduces the risk of recurrent venous thromboembolism as long as it is used. However, the absolute risk of recurrent venous thromboembolism declines over time, while the risk for major bleeding remains. Thus, the efficiency of vitamin K antagonist administration decreases over time since the index event.

Anticoagulants↗

In vitro screening of Haemonchus contortus third stage larvae for ivermectin resistance.

The indiscriminate repeated use of ivermectin has resulted in the emergence of ivermectin resistant field strains of Haemonchus contortus in sheep in South Africa. There is a need for a rapid and cost effective in vitro test to detect such strains. Infective H contortus larvae known to be resistant to ivermectin, were incubated in vitro in a diluted concentration of the drug. Subsequently their ability to migrate was compared with that of larvae of isolates known to be susceptible to ivermectin. The criterion used to determine resistance was the ability of the larvae to migrate out of gelled agar after exposure to ivermectin using diluted propylene glycol as the control compound. The results obtained by this technique confirmed the results obtained with critical controlled tests; significant differences between the ivermectin sensitive and resistant isolates were demonstrated, thereby confirming that this in vitro technique may be used as a screening method to identify ivermectin resistant isolates of H. contortus.

Animals↗

Pleural Mesocestoides and cardiac shock in an obese vervet monkey (Cercopithecus aethiops).

Only one case of infection by tetrathyridia larvae of the tapeworm genus Mesocestoides was detected in 416 necropsies of captive vervet monkeys (Cercopithecus aethiops). Two hundred nine larvae were distributed between both pleural cavities. Mass and size ranges of larvae were determined. A plasma cell reaction indicated a humoral immune response to parasite antigens, which may have contributed to acute, lethal cardiac shock. Coagulative myocytolysis was confirmed. The history of this case and associated circumstantial evidence and reports in the literature suggest that infection of primates by tetrathyridia probably occurs after capture rather than before.

Animals↗

Teaching veterinary parasitology.

The history of parasitology and the teaching of veterinary parasitology in South Africa are reviewed briefly. Courses in veterinary parasitology are presented at the faculties of veterinary science at the University of Pretoria and the Medical University of South Africa as well as at the Pretoria Technicon. At the University of Pretoria, the three disciplines of veterinary parasitology, entomology, helminthology and protozoology, are covered in 330 core lectures; from 13 to 40% of the contact time is devoted to practical classes. Teaching veterinary parasitology is both labour intensive and costly, viz. R1700 (US$570) per student per annum. Such costs are justified by the R148.8 million (US$49.6 million) spent every year in South Africa on anthelmintics, ectoparasiticides and vaccines to control parasites. Veterinary parasitology is a dynamic subject and the curriculum must be revised regularly to incorporate new information. Because the parasite faunas are so diverse no single textbook can satisfy the requirements of the various institutions worldwide which teach the subject, with the result that extensive use is made of notes. In Australia and in Europe, ticks and tick-borne diseases are less important than they are in Africa; consequently insufficient space is devoted to them in textbooks to satisfy the requirements of the subject in African countries. Parasite control under extensive and intensive conditions is dealt with adequately at the University of Pretoria, but increasing emphasis will be given to small-scale farming systems, particularly if alternative food animals are to be kept.

Animals↗

Gastro-intestinal parasites of the Samango monkey, Cercopithecus mitis, in Natal, South Africa.

Eight gastro-intestinal tracts of Cercopithecus mitis labiatus from Karkloof, Natal, and 121 fecal samples from C. m. erythrarchus from Cape Vidal, Natal, were examined for helminth parasites and/or their eggs. Fecal samples from six of the C. m. labiatus were examined for protozoan cysts. Five protozoon and six helminth species were identified from C. m labiatus. Most adult worms occurred in the caecum and colon, gut regions which also contained the highest volatile fatty acid levels. The eggs of nine helminth species were recovered from C. m. erythrarchus fecal samples; protozoans were not looked for in these samples.

Animals↗

Necropsies of eight horses infected with Strongylus equinus and Strongylus edentatus.

Ponies (n = 8) approximately 18 months old, were infected with 20,000 to 30,000 infective larvae of Strongylus equinus with less than 10% contamination with Strongylus edentatus larvae and necropsied 7 months post-infection. Lesions were present in the omentum, liver, pancreas, ventral colon, caecum and occasionally in the lungs. There were numerous intraabdominal adhesions and severe multiple granulomatous omentitis. Pancreatic damage, which characterises S. equinus, was exceptionally mild and was manifested mainly by slight periductular infiltration of eosinophils. Granulomas associated with larvae were found in the connective tissue associated with the pancreas. Larvae were recovered from the flanks, the peritoneum, the caecum and the kidney. Larval recovery was low, with a high percentage of the total number of larvae recovered in some of the carcasses being S. edentatus.

Animals↗

Treatment of cerebral coenuriosis in sheep with praziquantel.

Sheep (n = 14) with coenuriosis were treated with praziquantel in single or divided doses at total dosage rates of 50 to 500 mg kg-1 live mass. Nine of the sheep also received corticosteroid, diuretic and analgesic supportive therapy. Stress was avoided as far as practically possible. Treatment of one sheep with acute coenuriosis at a total dosage rate of 500 mg kg-1 praziquantel, was unsuccessful. Eight sheep were successfully treated at total dosages ranging from 100 to 500 mg kg-1 live mass, whereas dosages of 50 mg kg-1 were successful in 2 sheep only. Dosages of 50 mg kg-1 in 2 other sheep with multiple cerebral coenuri, were unsuccessful or only partially successful in killing parasites.

Acute Disease↗

Accidental pentobarbital poisoning in a lioness.

A lioness was accidentally poisoned by consumption of meat of a horse euthanased with pentobarbital. The post mortem examination was negative but thin-layer gas-chromatographic and mass-spectrometric methods revealed a pentobarbitone concentration of 1, 14 mg kg-1 in the chloroform extracts of the liver of the animal.

Animal Feed↗

A survey of helminths in domestic cats in the Pretoria area of Transvaal, Republic of South Africa. Part 1: The prevalence and comparison of burdens of helminths in adult and juvenile cats.

The helminths found in 1,502 necropsied cats were examined. The findings indicated that 65% of the cats were infested. The most prevalent helminths encountered were Ancylostoma tubaeforme (41%), Ancylostoma braziliense (25%), Dipylidium caninum (23%), Toxocara cati (11%), Taenia taeniaeformis (7.7%), Ancylostoma caninum (3.3%), Joyeuxiella fuhrmanni (2.5%), Ancylostoma ceylanicum (1.4%), and Physaloptera praeputialis (1.3%). The following helminths were recorded in fewer than 1% of the cats: Centrorhynchus spp., Pterygodermatites spp., Toxocara canis, Aleurostrongylus abstrusus and Vogeloides spp., This is the first record of the lungworms, A. abstrusus and Vogeloides spp. in cats in the Republic of South Africa. The helminths in adult and juvenile cats are compared. Of the cestodes, Joyeuxiella fuhrmanni (4%) and Taenia taeniaeformis (12%) are more prevalent in adult cats. Dipylidium caninum is marginally more common in adults (24%), and is the most common helminth in juvenile cats, being present in 21% of cases. More adult cats have Ancylostoma tubaeforme (58%), Ancylostoma braziliense (36%), Ancylostoma ceylanicum (2.4%) and Physaloptera praeputialis (1.9%) than do juvenile cats. However, juvenile cats were found to harbour more Toxocara cati (41%), Toxocara canis (0.5%) and Ancylostoma caninum (5.2%). Juvenile cats harbour appreciable numbers of both cestodes and nematodes, thus any treatment should be aimed at the elimination of both, with a broad spectrum anthelmintic.

Age Factors↗

Immunization of sheep against the larval stage of Taenia multiceps.

A trial with 200 ewes and 127 lambs showed that vaccination of lambs with 2 doses of Oncosphere Secretory Antigen (OSA) 4 weeks apart, at either 4-8 and 8-12 weeks or at 12-16 and 16-20 weeks of age, was equally effective in protecting them against infestation with the larval stage of Taenia multiceps. In this trial, the lambs of ewes, vaccinated with OSA when they were 90 and again 120 days pregnant, were as susceptible to infestation as the lambs of untreated control ewes. Another trial to provoke passive immunity in lambs gave inconclusive results. In a 3rd trial 2 doses of regular OSA and 2 doses of freeze-dried OSA protected all the lambs in each group, while a single dose of regular OSA protected 9 out of 10 lambs against cerebral lesions.

Animals↗

Parasitic pneumonia in a dog caused by a lung fluke of the genus Paragonimus.

Post mortem examination of a dog that died after a spell of respiratory distress revealed about 20 randomly distributed cystic lesions in the lungs. Those examined each harboured 2 light-brownish conical flukes approximately 10 mm in length. Histopathological examination of such a lesion revealed the presence of Paragonimus (lung fluke) embedded in it. The parasite had a typical spiny integument as well as other characteristics typical for the genus. Typical pigmented operculated eggs were embedded in the surrounding tissues. The life cycle of the parasite is briefly discussed.

Animals↗