bluuebunny/crossref_metadata_2025_split huggingface dataset:
A community trial of ivermectin for onchocerciasis in Sierra Leone: compliance and parasitological profiles after three and a half years of intervention
Authors: Whitworth J. A. G. , Downham M. D. , Lahai G. , Maude G. H. 
Published: November 2003

SummaryWe have studied the compliance patterns and the long‐term effects of repeated ivermectin at various dosing intervals in a randomized controlled trial. The setting for the trial was six neighbouring communities hyperendemic for onchocerciasis in southern Sierra Leone. A total of 335 subjects attended a survey 18 months after the fifth treatment round. Of those randomized to ivermectin, over 85 % had received at least three doses. There was no evidence that women of childbearing age were consistently under‐treated, despite the criteria for exclusion from treatment. An intention‐to‐treat analysis showed that a 6‐monthly ivermectin treatment regime satisfactorily suppressed microfilarial loads. Microfilarial repopulation was significantly slower over an 18‐month period after multiple doses compared to a single dose. Further analysis of microfilarial repopulation suggests that there is a cumulative suppressive effect after at least the first three doses of ivermectin, and that an annual treatment interval is as effective for short‐term microfilarial suppression as a 6‐monthly interval.
Field tests of a village‐based mollusciciding programme for the control of snail hosts of human schistosomes in Cameroon
Authors: Greer G. J. , Tchounwou P‐B. , Takougang I. , Monkiedje A. 
Published: November 2003

SummaryThe feasibility of using unskilled workers at the district or village level to perform mollusciciding activities in arid regions of northern Cameroon was investigated. A simplified procedure for application to temporary ponds, the principal sites of schistosomiasis transmission in that region, was tested. This consisted of mixing the required quantitity of niclosamide (Bayluscide, Bayer AG, Leverkusen) with pond water in a plastic watering can and applying the mixture around the circumference. To aid dispersion, the can was repeatedly swept from the perimeter toward the centre of the pond. Two ponds each were treated once near the end of the rainy season at 1 of 3 concentrations: 0.5, 1.0 and 1.5 p.p.m. Following treatment, 100% snail mortality was recorded at all concentrations. A simple, rapid method for determining the quantity of niclosamide needed to treat temporary ponds was also devised.Physical characteristics were determined for 16 potential schistosomiasis transmission sites in the region. An integration of those characteristics was used to develop a simplified scale indicating the quantity of niclosamide needed to treat ponds based on their circumference.The operational feasibility of a village based mollusciciding programme using those simplified procedures was then evaluated in 2 villages. Village health workers demonstrated a high accuracy (87%) in identifying potential schistosomiasis transmission foci and snail host populations were virtually eliminated from treated sites.
Prevalence of blindness and visual impairment in the region of Ségou, Mali. A baseline survey for a primary eye care programme
Authors: Kortlang C. , Koster J. C. A. , Coulibaly S. , Dubbeldam R. P. 
Published: November 2003

SummaryA community‐based cross‐sectional study on the prevalence and causes of blindness and visual impairment was conducted between July and August 1990 in three rural districts in Ségou region, Mali. The study population consisted of 5871 villagers. In the study area, the overall prevalence of bilateral blindness was 1.7% (standardized rate for age 2.0%± 0.4%), of bilateral visual impairment 1.7% (2.1%± 0.4%), of unilateral blindness 1.7% (2.2%± 0.4%) and of unilateral visual impairment 1.0% (1.2 ± 0.3%). No important differences were found between districts.Cataract was the most common cause of visual loss (54%) and was most prevalent among those over 50 years of age. In 43%, unilateral blindness was associated with trauma. Other major eye diseases accounting for high percentages of visual impairment were trachoma and glaucoma. Xerophthalmia appeared to be a major public health problem among children in the age group 0–5.It was concluded that blindness is a major public health problem in this region. Some recommendations are given for strengthening integrated primary eye care at the district level in Ségou region.
Topical chemotherapy for experimental African trypanosomiasis with cerebral involvement: the use of melarsoprol combined with the 5‐nitroimidazole, megazol
Authors: Jennings F. W. , Chauvière G. , Viode C. , Murray M. 
Published: November 2003

SummaryMegazol, one of a number of related 5‐nitroimidazoles, can be dissolved in dimethylsulphoxide and the solution can be converted into a gel by the addition of hydroxypropylcellulose which facilitates the ease and accuracy of administration. This megazol gel, when used in combination with melarsoprol (3.6%) in propylene glycol gel, will cure experimental CNS‐trypanosomiasis in mice. A single application of 0.1 ml of melarsoprol (3.6%) gel plus 0.1 ml of either 8 or 16 mg/ml megazol gel successfully treated experimental CNS‐trypanosomiasis while two consecutive days' treatment with 0.05 ml melarsoprol and 0.1 ml of 16 or 32 mg/ml megazol gels also produced satisfactory cures.
Impact of a mass vaccination campaign against a meningitis epidemic in a refugee camp
Authors: Haelterman Edwige , Boelaert Marleen , Suetens Carl , Blok Lucie , Henkens Myriam , Toole Michael J. 
Published: November 2003

SummarySerogroup A meningococcus epidemics occurred in refugee populations in Zaire in August 1994. The paper analyses the public health impact of a mass vaccination campaign implemented in a large refugee camp. We compared meningitis incidence rates from 2 similar camps. In Kibumba camp, vaccination was implemented early in the course of the epidemic whilst in the control camp (Katale), vaccination was delayed. At a threshold of 15 cases per 100000 population per week an immunization campaign was implemented. Attack rates were 94 and 134 per 100000 in Kibumba and Katale respectively over 2 months. In Kibumba, one week after crossing the threshold, 121 588 doses of vaccine were administered covering 76% of all refugees. Vaccination may have prevented 68 cases (30% of the expected cases). Despite its rapid institution and the high coverage achieved, the vaccination campaign had a limited impact on morbidity due to meningitis. In the early phase in refugee camps, the relative priorities of meningitis vaccination and case management need to be better defined.
Malaria control and fever management in Henan Province, China, 1992
Authors: Liu Xili , Jackson Sukhan , Song Jinduo , Sleigh Adrian C. 
Published: November 2003

SummaryHenan Province, which once had the highest malaria prevalence in China, had only 318 reported cases in 1992. Our purpose was to investigate this late ‘consolidation phase’ of malaria control in Henan with reference to malaria surveillance. We conducted a questionnaire survey of village doctors in Shang Shi Qiao Township during the transmission period of 1992. Of the 732 recorded fever cases, 16 were probable malaria cases by clinical and treatment response criteria, but only one received a full course of antimalarials. Of the 732 patients, 61% had fever every day, 37% went for treatment the first day, 52% waited 2–3 days and 10% waited longer. One hundred and twenty‐eight patients took self‐medication before seeing the doctor. Blood examination was carried out in 526 (71%) fever cases but only four were positive, all for Plasmodium vivax. Our findings highlight problems relating to patient behaviour and motivation of village doctors, malaria treatment, surveillance and microscopy, rural migration, economic development and malaria transmission. All need to be considered for reforming the malaria control strategy in Henan Province.
Plasmodium berghei mouse model: antimalarial activity of new alkaloid salts and of thiosemicarbazone and acridine derivatives
Authors: Loiseau P. M. , Xuong Nguyen Dat 
Published: November 2003

SummarySixteen compounds were synthesized and evaluated on Plasmodium berghei in CD1 mouse. The nature of the salt associated to the active principle can give some advantages in the field of activity, bioavailability and toxicity. β‐Resorcylic acid was chosen in this study because of its previously described antimalarial activity and its expected enhancement of quinine antimalarial activity. While treatment with subcutaneous quinine sulphate at 1 mmol/kg cured 6/10 mice, quinine β‐resorcylate cured all the mice under identical conditions.Although such a result appeared promising, in vitro investigation should be performed to draw clear conclusions regarding a synergy between quinine and β‐resorcylate. Cinchonidine β‐resorcylate was also active; all mice were cured at 1 mmol/kg and the mean survival time was 13.8 ± 2.4 days after a subcutaneous treatment at 0.5 mmol/kg in a single dose. In the series of acridines, (N‐α, ε‐dioxopentyl)‐5‐amino‐1,2,3,4‐tetrahydroacridine cured all mice at 50 μmol/kg under the same conditions. The maximum tolerated doses in mice ranged from 100 to 150 μmol/kg for these acridine derivatives. The chemotherapeutic index of (N‐α, ε‐dioxopentyl)‐5‐amino‐1,2,3,4‐tetrahydroacridine was estimated at 2–3. Other salts expected to reduce the toxicity, such as α‐ketoglutarate and p‐chlorophenoxyacetate, did not enhance the activity of the active principles. These results prompt us to further investigations including plasma kinetic evaluation in rats and in vitro on Plasmodium falciparum.
Direct amplification and species determination of microsporidian DNA from stool specimens
Authors: Katzwinkel‐Wladarsch S. , Lieb M. , Heise W. , Löscher T. , Rinder H. 
Published: November 2003

SummaryMicrosporidia are recognized as a major aetiological agent in chronic diarrhoea of immunocompromised patients. Their detection by light microscopy is hampered by the small size of the spores. A simple and rapid DNA extraction method has been developed for the detection of microsporidian DNA by PCR directly from stool specimens. It can be performed at room temperature in a 1.5‐ml microcentrifuge tube format in less than 1 hour. The subsequent nested polymerase chain reaction permits the detection of 3–100 spores in a 0.1‐g stool sample. The amplification products can be verified and the species Enterocytozoon bieneusi, Encephalitozoon cuniculi and Encephalitozoon (Septata) intestinalis distinguished by a simple restriction endonuclease digest.
The EI Niño Southern Oscillation and the historic malaria epidemics on the Indian subcontinent and Sri Lanka: an early warning system for future epidemics?
Authors: Bouma Menno J. , van der Kaay Hugo J. 
Published: November 2003

SummaryThe recurrent great malaria epidemics which occurred in the Punjab province of former British India and Ceylon before the introduction of residual insecticides have been related to excessive and failing monsoon rains respectively. In the arid Punjab, rainfall facilitated breeding and increased the lifespan of the mosquito vector and, in the wet part of Ceylon, failing monsoon rains caused rivers to pool, creating more favourable breeding conditions. The periodic fluctuations in monsoon rainfall and epidemic malaria are here explained in relation to the El Niño Southern Oscillation. In the Punjab, epidemic malaria between 1868 and 1943 correlates significantly (r=0.34, P<0.005) with the sea surface temperature anomalies in the Eastern Equatorial Pacific, a parameter of the oscillation, and epidemics were significantly more prevalent in a year with a wet monsoon following a dry El Niño year than in other years. In Ceylon, epidemics were significantly more prevalent during El Niño years, when the same south‐west monsoon tends to fail. With the reduced reliance on residual insecticides and the recurrence of epidemic malaria on the Indian subcontinent, advances made in predicting El Niño events may be used to forecast high and low risk years for future malaria epidemics.
Ultrasonographic assessment of the adulticidal efficacy of repeat high‐dose ivermectin in bancroftian filariasis
Authors: Dreyer G. , Addiss D. , Noroes J. , Amaral F. , Rocha A. , Coutinho A. 
Published: November 2003

SummarySince diethylcarbamazine, the drug recommended for treatment of lymphatic filariasis, seems only partially effective against the adult worm, intense interest persists in identifying a macrofilaricidal drug for this infection. To evaluate directly in vivo the macrofilaricidal activity of repeat high‐dose ivermectin, 15 men who had living adult Wucbereria bancrofti detected in the scrotal area by ultrasound were treated with 400 μg/kg of ivermectin at 2‐week intervals for 6 months (total dose, 4.8 mg/kg). Serial ultrasound examinations were performed before, during, and for 6 months after treatment. Profound suppression of microfilaraemia followed the first dose of ivermectin, but movements characteristic of the adult worm on ultrasound remained unchanged both in location and pattern. Even when given in total doses of 4.8 mg/kg, ivermectin appears to have no observable activity against adult W. bancrofti, although its ability to suppress microfilaraemia makes it potentially useful for the control of lymphatic filariasis.
Autochthonous cutaneous larva migrans in Germany
Authors: Klose C. , Mravak S. , Geb M. , Bienzle U. , Meyer C. G. 
Published: November 2003

SummaryCutaneous larva migrans syndrome is extremely rare in Germany. However, three cases of this syndrome were diagnosed in patients from Berlin, Germany, in the summer of 1994. Exposure to the infective agent in endemic areas and close contact with animals were excluded. It is assumed that the extreme temperatures in summer 1994 favoured the conditions of infection.
Plasmodium falciparum malaria in the first year of life in an area of intense and perennial transmission
Authors: Kitua A. Y. , Smith T. , Alonso P. L. , Masanja H. , Urassa H. , Menendez C. , Kimario J. , Tanner M. 
Published: November 2003

SummaryA longitudinal study of Plasmodium falciparum malaria in infants in Idete village, south‐eastern Tanzania, was conducted over a period of 14 months in order to determine the incidence of P. falciparum infection and clinical malaria in the first year of life. Of 1356 blood slides from cross‐sectional surveys, 52.1% were positive for asexual stages of P. falciparum. There were marked increases in P. falciparum prevalence, parasite densities, overall fever incidence and the incidence of malaria fevers with age for the first 6 months of life. The average attack rate, estimated from a reversible catalytic model, was 0.029 per day with a slight increase with age but there was no initial period of protection against infection in neonates. Estimated average duration of infections was 64 days, with infections in older infants lasting much longer than those contracted during the first 2 months of life.These results support the hypotheses that the main effect of passively transferred maternal immunity to malaria is in the control of asexual stage parasites, and that the level of clinical immunity depends upon the extent of recent exposure to parasites. Infants as young as 4 months of age are at high risk of clinical attacks. Intervention programmes against malaria in areas of the highest transmission should therefore be designed to include this group.
Response of an acetolactate synthase (ALS)‐resistant biotype of Amaranthus rudis to selected ALS‐inhibiting and alternative herbicides
Authors: SPRAGUE C. L. , STOLLFR E. W. , WAX L. M. 
Published: November 2003

SummaryAn Amaranthus rudis Saner (common water‐hemp) biotype from a field treated for two consecutive years with a mixture of chlorimuron and metribuzin was tested in greenhouse and laboratory studies to assess resistance and cross‐resistance to four acetolactale synthase (ALS)‐inhibiting herbicides. The biotype demonstrated >1920‐fold resistance at the whole plant level, and >850‐fold resistance at the ALS enzyme to chlorimuron, compared with a susceptible biotype. This chlorimuron‐resistant biotype was also cross‐resistant to primisuifu‐ron, haiosulfuron and imazethapyr. In greenhouse studies, atrazine alone or in combination with ALS‐inhibiting herbicides provided excellent control of the resistant biotype of A. rudis. Combinations of dicamba and ALS‐inhibitors also provided adequate control. Additionally, premixtures of flumetsulam and metolachlor and of dicamba and atrazine furnished excellent control of this chlorimuron‐resistant A. rudis biotype.
Germination behaviour of two morphologically different types of seed of Cassia tora at different temperatures
Authors: BHATTACHARYA A. , SAHA P. K. 
Published: November 2003

SummaryThe effect of temperature on the germination response of two categories of morphologically different seeds of Cassia tora L. was investigated. Germination response of dormant seeds (category A with closed ultraastructures) was not affected by temperature, as 96% of the seeds germinated at all temperatures on scarification. On the other hand, non‐dormant seeds (category B with open ultrastructures) were temperature sensitive and germinated best at 32°C. However, storage affected the germination responses of both types. While the category A seeds lost moisture gradually with storage time and retained viability for a longer period, i.e. 2 years, the moisture loss in category B seeds was noted only after 2 years and the seed viability was retained for only 1 year. The production of two morphologically and physiologically distinct types of seed simultaneously by C. tora is probably an ecological adaptation for progressive emergence of the species over long periods in the field.
Dose response of weeds to methyl iodide and methyl bromide
Authors: ZHANG W. M. , McGIFFEN M. E. , BECKER J. O. , OHR H. D. , SIMS J. J. , KALLENBACH R. L. 
Published: November 2003

SummaryLabonuory bioassay and field experiments were conducted to characterize the dose response of weeds to methyl iodide and methyl bromide as soil fumigants. The patterns in potency of both fumigants and in sensitivity of diffcretit weed species to the fumigants were distinguished with the use of logistic dose‐response models. Similar to its response to methyl hromide fumigation. Amaranthus retrofleus L. was the most sensitive to methyl iodide fumigation. Cyperus rotundtis L. was the least sensitive to methyl iodide fumigation, whereas Portuloca oleracea L. was the least sensitive to methyl hromide. Lolium multiflorum Lam. Abutilon theophrasti Medik.Chenopodium album L. P. ateracea. Brassica kaber (D.C.) L.C. Wheeler and Cyperus escuden‐tus L. were similar in sensitivity to methyl iodide. Methyl iodide was as potent as methyl bromide for A. retroflexus but more potent than methyl bromide for L. multiflorum, A. theophrasti. C. album. P. oleracea. B. kaber, C. esculentus and C. rotundus. The dose response for weeds in the field was similar to that obtained in laboratory bioassays. Under fieid conditions. 280 kg ha‐1 methyl iodide killed all species tested except Solanum nigrum L Methyl iodide appears to be a suitable replacement for meihyl bromide because it can be used in situations simitar to methyl bromide fumigation, has superior efficacy against a broad spectrum of pests and has a low potential for degrading the earth's ozone lavers.
A model of the cost of delay in spraying weeds in cereals
Authors: BLACK I. D. , DYSON C.B. 
Published: November 2003

SummaryUsing a previous model as a base, data derived in field trials in wheat (Triticum aestivuort L.) and bailey (Hordeum vulgare L.) were assessed to estimate the yield penalty, and resulting reduction in economic benefit, from progressive spraying of herbicides up to late crop tillering. Compared with early post‐emergence application, yield penalties from delayed spraying began at early tillering. For median values of weed‐free yield and weed density in the data set. the loss in potential yield increase when spraying at late tillering compared with early post‐emergence was 71%, Crops with higher weed‐free yield potential and with greater initial weed density showed a proportionately (as well as absolutely) larger yield penalty from a moderate delay in spraying, indicating an earlier and more intense onset of competition with weeds.
Growth and regenerative capacity of plants of Cirsium arvense
Authors: GUSTAVSSON ANN‐MARIE DOCK 
Published: November 2003

SummaryThe undisturbed growth and regenerative capacity of the root system of Cirsium arvense (L.) Scop, were studied in one glasshouse and one field experiment. In the glasshouse experiment, two lengths of root fragment from the same clone, previously grown at two nitrogen levels, were planted in boxes. Plants that developed from these fragments were inspected on eight occasions to assess their undisturbed development and growth, above and below ground, and their regenerative capacity after disturbance by burial at different points of development. The initial nitrogen content of the roots had no effect on growth measurements, but longer root fragments produced greater masses of primary shoots, new roots and shoots from the new roots than did shorter ones. After disturbance at early stages (4‐7 leaves with a minimum length of 5 cm), plants originating from shorter root fragments did not regrow at all. Plants originating from longer root fragments exhibited a minimum regenerative capacity when disturbed at the eight‐leaf stage. In the field experiment, root fragments of length 12 cm. from the same clone, were planted in October 1991 at 5 cm or 20 cm depth. Plants that developed from these fragments were studied on 12 occasions, from April to July 1992. Plants emerging from a depth of 20 cm reached a point of positive net assimilation 28 days (380 day degrees) later than those developing from a depth of 5 em. The plants exhibited a minimum regenerative capacity when their primary shoots had. on average. 10 (plants from 5‐cm root fragments) or seven (plants from 20‐cm root fragments) expanded leaves.
Horizontal movement of seeds following tine and plough cultivation: implicationsfor spatial dynamics of weed infestations
Authors: REW L. J. , CUSSANS G. W. 
Published: November 2003

SummaryHorizontal movement of seeds by different cultivators was investigated in three experiments. Seeds of barley (Hordeum vulgare L.), field bean (Vicia faba L.) and oilseed rape (Brassica napus L.) were positioned on the soil surface or buried 0.1 m deep prior to cultivation, Seed movement was assessed by counting germinated seedlings. The type of tine implement used significantly affected mean seed movement, with surface‐sown seeds being moved significantly further than buried seeds. Primary cultivation with flexi‐ or spring‐tine machines moved seeds further than straight‐tine or power harrow implements. However, there was no overall difference between plough and flexi‐tine mean seed movement. A single pass with a tine attached to a seed drili moved seeds less than the two passes with tine plus seed drill, but the first pass had the greatest effect. Small oilseed rape seeds moved significantly further than larger barley or field bean seeds. More than 84% of seeds moved ≤ 1m from the source: no seeds were observed>4.8m in a forward direction or >0.2m backwards from the source, In a fourth experiment, plots containing seeds of Sinapis arvensis L. were cultivated in alternate directions in successive years, The results broadly validated the findings of the previous experiments Quantifying the horizontal movement of weed seeds is important to the understanding of the spatial dynamics of weed patches and thus in the prediction of future weed distributions.