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At least 253 records · Page 14Linked to original sources
PubMed1983

Usefulness of apheresis to extract microfilarias in management of loiasis.

Two patients with loiasis in whom treatment with diethylcarbamazine had to be interrupted because of serious side effects underwent apheresis to extract microfilarias from the blood. After three apheresis sessions the number of microfilarias in the blood had dropped from 8980 to 3412/ml in one patient and from 2950 to 1840/ml in the other. Between 40 and 45 X 10(6) microfilarias were removed from each of the patients. After reduction of the parasitaemia the two patients were given diethylcarbamazine; no appreciable side effects occurred, and the patients were cured.

Adult↗
PubMedDate not supplied

Microfilariae in a cytologic smear from cavernous hemangioma of the liver. A case report.

BACKGROUND: Wuchereria bancrofti has been found in almost every tissue except the liver. CASE: Microfilariae were found in a hemangioma of the liver on fine needle aspiration in a 40-year-old female with pyrexia associated with hepatomegaly and a peripheral blood smear negative for microfilariae. CONCLUSION: Absence of microfilariae in a peripheral blood smear does not exclude filarial infection.

Adult↗
PubMed1978

A new staining technique for microfilariae.

A rapid whole mount staining method is described to identify and differentiate microfilariae without elaborate processing. A single solution combining Hoyer's mounting medium and hematoxylin stain facilitates light microscopic examination of nuclei and sheaths of microfilariae. The new technique stains microfilariae adequately in three to seven minutes at 60--64 C making the method preferable to conventional methods that may take as long as 45 to 60 minutes. Lantern heat may be used to heat slides in rural areas with good results.

Animals↗
PubMed1976

Microfilaria of Wuchereria bancrofti in bone marrow smear.

Microfilariae of Wuchereria bancrofti were detected in seven cases of anemia in persons with asymptomatic filariasis. In three cases microfilariae could not be detected in the blood. Their presence in bone marrow may indicate the ability of microfilariae to cross the vessel wall.

Adult↗
PubMed1981

The use of aceto-orcein-stained squash preparations for enumeration of nuclei in microfilariae of various filarial parasites.

The nuclear numbers of situated between the cephalic space and the nerve ring (CS-NR) in the microfilariae of six filarial species were examined. For the counting of nuclei, aceto-orcein squashing preparations were used. This procedure revealed nuclei clearly visible under the phase-contrast microscope. The mean number of nuclei in the CS-NR region was very similar between Brugia pahangi and B. malayi, but was statistically different between Onchocerca volvulus and O. gutturosa. In the microfilariae of O. volvulus, two types of nuclei were clearly shown in this region. The procedure described is useful in the anatomical study of microfilariae.

Animals↗
PubMed1987

Increased dissemination of dengue 2 virus in Aedes aegypti associated with concurrent ingestion of microfilariae of Brugia malayi.

We investigated whether concurrent ingestion of dengue 2 virus and microfilariae of Brugia malayi would increase viral infection and dissemination rates in Aedes aegypti. Infection rates were similar in mosquitoes that ingested virus alone or both virus and microfilariae concurrently. However, viral dissemination rates, as determined by recovery of dengue virus from both legs and bodies separately, were significantly greater in mosquitoes that ingested both agents concurrently than in those that ingested virus alone. This study confirms that vectorial capacity of a natural vector of an arbovirus may be enhanced by the concurrent ingestion of microfilariae.

Aedes↗
PubMed1988

Filariasis in Gabon: human infections with Microfilaria rodhaini.

In examining skin snips from 1,830 Gabonese 32 were found to have microfilariae indistinguishable from Microfilaria rodhaini. The microfilaria is 300.2 microns long and 2.2 microns wide. Specific clinical signs were not identified, as the same person often was infected by other filaria.

Adult↗
PubMed1993

Mechanism of increased dissemination of chikungunya virus in Aedes albopictus mosquitoes concurrently ingesting microfilariae of Dirofilaria immitis.

We investigated whether concurrent ingestion of chikungunya virus and microfilariae of Dirofilaria immitis increases viral dissemination and multiplication in a mosquito vector. The increased rate of dissemination of this virus in mosquitoes concurrently ingesting both agents was found when homogenates of bodies and those of legs only were examined. It was significantly higher than that of controls ingesting the virus alone through the end of the experiment on day 14 after infection. We next studied the mechanism by which the presence of microfilariae enabled the virus to enter into the hemocoel and to reach the salivary glands. We checked our results using histopathologic procedures and electron microscopy by identifying holes produced by the microfilariae that penetrated the midgut epithelial layer. When the midgut of mosquitoes was punctured with a thin needle immediately after the mosquitoes ingested viruses, higher infection rates were observed than in mosquitoes without such punctures.

Aedes↗
PubMed1998

Bancroftian filariasis in Maceio, state of Alagoas, Brazil: Observations on Culex quinquefasciatus after blood feeding on individuals with different densities of microfilariae in the peripheral blood stream.

Females of laboratory-reared Culex quinquefasciatus were allowed to take blood meals on individuals with low (1-100 microfilariae/ml of peripheral blood), moderate (101-500 microfilariae/ml), and high (> 500 microfilariae/ml) microfilaremia. The mosquitoes ingested 1.39-3.80 microl of blood and infective third-stage (L3) larvae were first recorded 13-14 days after the infecting blood meal. The number of microfilariae ingested by mosquitoes was proportional to the density of microfilariae in the peripheral blood of the human subjects, but with a concentration factor of up to 6.5 times the expected number. Survival of mosquitoes was not influenced by the density of microfilariae in the peripheral blood of infected individuals. Infectivity indices were proportional to microfilaremia in human subjects. The number of L3 larvae/female (intensity of infection) was not influenced by individual microfilaremia. The highest vector efficiency and the best experimental infection index were recorded in mosquitoes that blood fed on individuals with moderate microfilaremia. The results are discussed in relation to the transmission on Bancroftian filariasis in the study area.

Adolescent↗
PubMed1975

[Investigations on the filariidae of the cervidae in Southern Germany. 1. Development of the nodule, finding of the sexes and production of the microfilariae in Onchocerca flexuosa (Wedl, 1856), in the red deer (Cervus elaphus) (author's transl)].

The biology of O. flexuosa was studied during the examination of numerous subcutaneous nodules, which were taken from the hides of red deer of all age-classes. In fawns the development of the nodule is induced by the immature stages, probably by the females. At the same time a hematome is formed. Males of different ages penetrate into the nodule where mature or immature females are present. Later they mate and remain within the nodule until the microfilariae in the uteri of the females develop. Usually 1 or 2, occasionally 4 females are found together. During the development of the embryos in the uteri the initially stretched female winds up. Only a short anterior part remains always straight. It is put out through the wall of the capsule in order to release the microfilariae. The males are often the majority reaching to 13 in one nodule. During the release of the microfilariae the males are found outside the nodule on the surface or near-by in the subcutaneous connective tissue. Both sexes are able to mate a second time. In older deer the males are also able to induce the development of nodules.

Aging↗
PubMed2002

Immunocytochemical localization of antigens recognised by tropical pulmonary eosinophilia and individuals with intestinal helminths antisera in microfilaria of Wuchereria bancrofti.

Ultrathin sections of microfilaria of W. bancrofti embedded in the hydrophilic resin L.R. White were incubated with sera from patients with a typical picture of filarial tropical pulmonary eosinophilia (TPE) and sera from patients of a non-endemic region for filariasis regarding intestinal helminths. Both groups had a similar pattern of labelling, except that the labelling intensity was higher with the sera of patients with filarial TPE. The present study indicates relevant epitopes recognised by sera from TPE-patients and also individuals with intestinal helminths in all tissues of microfilaria of W. bancrofti, instead of being localised in a specific nematode region. These findings suggest that sera from people from an area not endemic for filaria, harbouring intestinal helminths, also share antifilarial antibodies that recognise antigens of microfilaria of W. bancrofti.

Adult↗
PubMed1992

On the uptake of Wuchereria bancrofti microfilariae in vector mosquitoes of different susceptibility to filarial infections.

The quantitative uptake of Wuchereria bancrofti microfilariae by mosquito species of different susceptibility to filarial infection was studied. There was no relationship between the degree of susceptibility and the number of ingested microfilariae. However, in all tested mosquito strains the females ingested as a mean 1.2-1.9 times more microfilariae of W. bancrofti than expected.

Aedes↗
PubMedDate not supplied

The preferential site of adult Wuchereria bancrofti: an ultrasound study of male asymptomatic microfilaria carriers in Pondicherry, India.

BACKGROUND: The traditional method of detection of microfilaria in night blood specimens for the diagnosis of Wuchereria bancrofti infection is being replaced with circulating filarial antigen in day blood specimens, which has a high sensitivity. However, both methods are indirect tests to detect the presence of adult worms in vivo. Localization of adult worms in vivo in their natural habitat may help in understanding better the end-point of drug treatment, the adulticidal action of antifilarial drugs, and in locating the site of lymphatic pathology. We used ultrasound examination to assess the preferential location of adult worms in an area endemic for lymphatic filariasis. METHODS: Ultrasound examination was done in 36 asymptomatic male carriers of Wuchereria bancrofti microfilaria to detect the location of adult worms. Both sides of the scrotum (root of the scrotum, epididymis, spermatic cord, testis and the adjoining area), lymphatic vessels and inguinal, popliteal, axillary and epitrochlear lymph nodes were examined using a 7.5 MHz probe in real-time B mode. RESULTS: The 'filaria dance sign (FDS)' suggesting the presence of adult worms was observed in 22 carriers (61%). The preferential site of location of the adult worms was the intrascrotal juxtatesticular lymphatic vessels in 'nests' along the lymphatic vessels of the epididymis, spermatic cord and paratesticular region. The number of nests varied between 1 and 4 with a mean size of 0.3 cm2. In 95% of cases, localization of the worms was unilateral. The mean microfilaria (SD) count-positive cases for those with the filarial dance sign (264 [199]) was significantly higher (p<0.05) than for the negative cases (171 [196]). CONCLUSION: Ultrasound visualization of adult worms of Wuchereria bancrofti in vivo is possible and confirms the concept that the worms have their own territory and reside in 'nests'. The preferential site of localization of the adult worms in men is the intrascrotal juxtatesticular lymphatic vessels.

Adolescent↗
PubMed1991

In vitro effects of 2-tert-butyl-benzothiazole derivatives on microfilariae of Litomosoides carinii, Brugia malayi and Acanthocheilonema viteae.

Six 2-tert-butyl-benzothiazole derivatives (2-tert-butyl-6-iso-thiocyanato-5-methyl-benzothiazole CGP 21306); 3-[(2-tert-butyl-5-methyl-benzothiazole-6-yl) aminothiocarbonylthiol] propionic acid (CGP 21835); 2-tert-butyl-5-methyl-6-(N-methyl-piperazinyl-thiocarbonylamino)-b enzothiazole (CGP 21833); 2-tert-butyl-5-methyl-6-(4-dimethylamino-piperid-1-yl-thiocarbo nylamino)- benzothiazole (CGP 26702); CGP 20376, the 5-methoxy analogue to CGP 21835 and CGP 20309, the 5-methoxy analogue to CGP 21833) with known, high filaricidal activity in vivo were tested for in vitro efficacy against microfilariae of L. carinii (Lc), B. malayi (Bm) and A. viteae (Av) in order to study intrinsic antifilarial activities. All drugs affected the motility of the microfilariae of the three species in a species, dose and time dependent fashion. Lc was the most sensitive, Av the most resistant species. CGP 20376 and 21835 were the most effective compounds followed by CGP 21306. Complete immobilization of microfilariae was observed after 20 h in protein-free medium RPMI 1640 at drug concentrations of 0.1 to 10 nmol/ml. Effects were still marked 2 when graded on a 4 (full motility) to 0 (immobile) scale at concentrations of 0.01-0.1 nmol/ml. In the case of the thiourea derivatives CGP 21833, 26702 and 20309 concentrations had to be increased 10-100 fold to obtain similar effects. When proteins were present in the incubation medium (10% foetal calf serum, 100% normal serum) the efficacy of the compounds was reduced, i.e. drug concentrations had to be increased up to 100 fold to produce similar effects as in protein-free medium.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Impact of surface modifications of Acanthocheilonema viteae microfilariae on cell adhesion.

Exposure of A. viteae microfilariae to various lectins reduced their capacity to react with the peritoneal exudate cells of the host, Mastomys natalensis. Sugars corresponding to these lectins with the exception of N-acetyl glucosamine, did not affect the adhesion per se. They however, protected the parasite against the adverse effect of lectins. Neuraminidase and chitinase also suppressed adhesion capacity of the microfilariae. Except sodium dodecylsulphate which enhanced cell attachment, other surfactants inhibited this reaction considerably. The results indicate that antibody dependent adhesion of the microfilariae with the macrophages involves surface moieties of the parasite, where N-acetylglucosamine acts as the principal sugar residue. Participation of -SH groups also is inferred from the observations that p-chloromercuribenzoate and dithiobis-(2-nitrobenzoic acid) inhibited cell attachment and dithiothreitol provided protection against these agents.

Acetylgalactosamine↗
PubMed1991

Survival and infectivity of Brugia malayi microfilariae after cryopreservation.

Methods were studied for the cryopreservation of microfilariae of periodic Brugia malayi. RPMI-1640 tissue culture medium containing 6% dimethyl sulfoxide (DMSO) and 15% newborn calf serum was used as cryoprotectant. Samples were frozen slowly in the vapor phase of liquid nitrogen prior to emersion in liquid nitrogen (-196 degrees C). The freezing rate was -0.5 to -1.0 degrees C per minute, microfilariae remained viable for as long as, 212 and 375 days, survival rates were 94 to 98% and they were infective to Aedes togoi mosquitos. The infective larvae (L3) were obtained for 10-11 days after feeding at 28 degrees C room-temperature and the infection rate of L3 in test mosquitos was 22.4-30.6%. All DMSO should be removed from the freezing medium to restore microfilariae activity after freezing.

Aedes↗
PubMed1991

Quantitative cellular cytotoxicity to Brugia malayi microfilariae: in vitro studies of sera from an area endemic for filariasis in Andhra Pradesh, India.

The extent of eosinophil and neutrophil cell-mediated cytotoxicity on Brugia malayi microfilariae by sera from an area endemic for bancroftian filariasis in Andhra Pradesh, India, has been studied in vitro in terms of the clinical status of the subjects. At physical examination, 66 serum samples were collected. Group "A" included patients with various disease manifestations like lymphoedema, hydrocoele, lymphangitis and elephantiasis. Group "B" had microfilaraemia ranging from 1-300/ml of blood. Subjects with no history of infection past or present (endemic normals) were studied as Group "C". Out of 38 sera tested individually with eosinophils, 14/18 of Group A, 10/11 of Group B and 7/9 of Group C promoted higher (21-97%), moderate (18-88%) and highest (51-95%) range of cytotoxicity, respectively. The age, clinical status and duration of disease among the infected subjects appeared to correlate with the microfilarial mortality. In Group B, we observed the highest microfilarial count (16-300/ml) in lower (1-20 yrs) age groups. These individuals promoted higher (77-83%) cytotoxicity compared to the older age group (21-40 or 41-60) with low (1-36/ml) microfilaraemia. Group C sera were highly toxic to microfilariae. All those that were positive promoted greater than 50% mortality. Eighteen nonendemic normal sera had no effect on microfilariae. The overlapping but differential toxicity of the sera indicates that various clinical manifestations are associated with different types of cellular and humoral responses. These studies should help focus identification of the target epitopes of various immune responses of the host.

Adolescent↗
PubMed1978

A simple technique to assess the total number of Onchocerca volvulus microfilariae in skin snips.

A technique for the assessment of the total number of microfilariae in skin snips from onchocerciasis patients is described. For the digestion of the skin tissue the biopsies are incubated at room temperature for 24 hours in medium 199, containing 3 mg/ml collagenase and antibiotics. This process leaves the microfilariae unharmed. A comparative study of the emergence of the microfilariae in different media showed that only 20% of the total number were released after 30 minutes in distilled water. After 24 hours incubation in isotonic saline 80% were found.

Humans↗