Buttner DW et al. (1985) Trop Med Parasitol "The fine structure of adult Onchocerca volvulus recovered by collagenase digestion."

Mac Donald A, Buttner DW

[Trop Med Parasitol, 1985]

Very young, middle-aged and old macrofilariae of Onchocerca volvulus were isolated alive or intact from onchocercomata using the collagenase digestion technique and studied by transmission electron microscopy. The body wall and the internal organs showed a well preserved morphology and no differences were detected compared with worms which had not been in contact with collagenase solution.

Buttner DW et al. (1988) Trop Med Parasitol "Histological examination of adult Onchocerca volvulus and comparison with the collagenase technique."

von Essen J, Albiez EJ, Erichsen J, Buttner DW

[Trop Med Parasitol, 1988]

The methods used for the assessment of adult Onchocerca volvulus by histology are described. Based on the results of several studies, mainly in Liberia and Burkina Faso, the morphology of the adult filariae in histological sections is represented as far as it is relevant for the evaluation. Especially are described the morphological alterations due to old age of the worms, to chronic hyperreactivity of the human host (sowda) and effects of the macrofilaricidal suramin and of microfilaricidal drugs. Quantitative results are reported on untreated adult O. volvulus from various countries, the changes of the worm population during 12 years of vector control in Burkina Faso and the effects of suramin, diethylcarbamazine, metrifonate, and ivermectin. The data from the histological examinations are compared with those gained from the examination of worms isolated by the collagenase technique in the same studies.

Buttner DW et al. (1983) Bull Soc Pathol Exot Filiales "Parasitological studies on "Onchocerca volvulus" eight years after interruption of the transmission in Upper Volta."

Parow D, Buttner DW, Albiez EJ

[Bull Soc Pathol Exot Filiales, 1983]

The macrofilaria population was analysed in a hyperendemic focus in western Upper Volta to determine the effect of eight years of Simulium control on the adult Onchocerca volvulus. During the first months of 1983 in three neighbouring villages 629 out of 786 inhabitants were examined for onchocerciasis and from 76 patients as far as possible all onchocercomata were extirpated. The macrofilariae were isolated from the nodules after collagenase digestion and examined microscopically. There were no major differences between men and women or different age groups. The average worm burden was 9.8 live macrofilariae per patient. All worms were several years old but developing sperms were found in 94% of the male and embryos in 55% of the female filariae. 36% of all worms were dead and 23% were calcified. Compared with the findings in a Liberian focus with continuous transmission it is concluded that the interruption of the transmission has lead to a reduced worm burden of entirely old worms but that a few more years of control will be needed until the production of microfitariae will end.

Franz M et al. (1983) Tropenmed Parasitol "The fine structure of adult Onchocerca volvulus. V. The digestive tract and the reproductive system of the female worm."

Franz M, Buttner DW

[Tropenmed Parasitol, 1983]

The morphology of the oesophagus, the intestine, the ovary, the uterus, the vagina and some inclusions in the body cavity are described in worms of different ages. The oesophagus wall comprises mostly muscle fibrils and a few glandular regions located only in the posterior portion. In the lumen, some material was found. From the anterior to the posterior end, the lumen of the intestine is reduced. The plasm of the intestinal cells of older worms is filled with concentric spherules containing iron, which are absent in mature but not full-grown worms. The ovarial cells contain in their outer region some fibrils and in the inner region some dense bodies. The ring-muscles of the uterine wall run in clefts of the basal lamina. They usually have accumulated iron containing bodies. In the final portion of the uterus and in the vagina the muscles are very thick. A comparison of the general morphology of the midbody regions of young, not full-grown worms, one less than five years old worm and some worms at least five years old is given.

Franz M et al. (1983) Tropenmed Parasitol "The fine structure of adult Onchocerca volvulus IV. The hypodermal chords of the female worm."

Buttner DW, Franz M

[Tropenmed Parasitol, 1983]

The morphology of the hypodermal chords in the anterior, midbody and posterior region and in worms of different ages are described and the amphids, the cephalic papillae and the nerve ring are demonstrated. At the anterior end, the hypodermal cap comprises the sensory organs. Close behind, the hypodermal chords are differentiated, and several cell margins are found in all of them. Four sublateral chords are differentiated, and several cell margins are found in all of them. Four sublateral chords are also found in the anterior region. A row of median cells is found between the dorsal and ventral syncytia further behind and at the posterior end. In the midbody region, the lateral chords are very large but without central cells. Various particles and inclusions such as bacteria, dense bodies and fibrils are found in the plasm of the hypodermal chords. A large multilayered inclusion was found in the degenerating chord of a female worm at least five years old.

Franz M et al. (1983) Tropenmed Parasitol "The fine structure of adult Onchocerca volvulus. III. The cuticle, the interchordal hypodermis and the muscle cells of the female worm."

Franz M, Buttner DW

[Tropenmed Parasitol, 1983]

The morphology of the cuticle, the interchordal hypodermis and the muscle cells of three mature but not full-grown worms, one worm less than five years old, two worms at least five years old and seven worms of unknown age are described. The cuticle in the anterior region is very similar to that of the male worm, however, in the midbody region the cuticular structure is more simple. The length of the folds of the surface membrane and the thickness of the coat vary considerably. The outer surface of the hypodermis is increased by lamellae, the inner surface by a labyrinthine system of folds. The structure of the muscle cells is simpler than in the male worm: degenerative alterations are found frequently comprising reduction of the afibrillar portion, separation of the filaments from the septa, disintegration of the filaments, and separation of the plasma from the laminae and finally total disintegration of the cell, leaving the empty laminal coverings behind.

Franz M et al. (1986) Trop Med Parasitol "Histology of adult Brugia malayi."

Buttner DW, Franz M

[Trop Med Parasitol, 1986]

Two male and two female Brugia malayi were collected from Mastomys natalensis, and cross sections from various regions of these worms were studied. The body wall of the female worm is thin throughout its length, whereas in the midbody and posterior region of the male worm the somatic muscles form a thick layer. In both sexes the intestine is thickest immediately behind the oesophagus and tapers posteriorly. The lumen was empty in all sections. In both genital tubes of the female worm a successive row of developmental stages could be observed. The rather short ovaries lie in the posterior region. The fertilisation chambers and the following regions are the thickest portions of the uteri. The testis is situated in the anterior region of the male worm, whereas in the midbody and posterior regions the vas deferens contains stretched spermatozoa. Compared to other filariae the sexual dimorphism is not very pronounced in this species.

Comber SD et al. (2006) Environ Pollut "Chronic toxicity of sediment-associated linear alkylbenzene sulphonates (LAS) to freshwater benthic organisms."

Hoss S, Webb S, Comber SD, Conrad AU, Marshall S

[Environ Pollut, 2006]

The toxicity of linear alkylbenzene sulphonates (LAS), to freshwater benthic organisms was assessed during exposure to spiked sediment. Lethal and sub-lethal end-points were monitored for two organisms (oligochaete Lumbriculus variegatus and nematode Caenorhabditis elegans). Results demonstrated relatively low toxicity (LOECs >100mg/kg dry weight). No observed effect concentrations (NOECs) of 81mg/kg dw (Lumbriculus) and 100mg/kg dw (Caenorhabditis) were determined. For the oligochaete, no specific endpoint was particularly sensitive to LAS. For the nematode, egg production was the most sensitive endpoint. Significant degradation was measured over the 28-day duration of the Lumbriculus study, equating to a half-life of 20days in sediment.

Brattig NW et al. (2001) Microbes Infect "Neutrophil accumulation around Onchocerca worms and chemotaxis of neutrophils are dependent on Wolbachia endobacteria."

Buttner DW, Hoerauf A, Brattig NW

[Microbes Infect, 2001]

Unlike in many other helminth infections, neutrophilic granulocytes are major cellular components in the hosts immune response against filarial worms. The pathways that drive the immune response involving neutrophils are unclear. This study shows that Wolbachia endobacteria (detectable by polyclonal antibodies against endobacterial heat shock protein 60 and catalase and by polymerase chain reaction being sensitive to doxycycline treatment) are direct and indirect sources of signals accounting for neutrophil accumulation around adult Onchocerca volvulus filariae. Worm nodules from untreated onchocerciasis patients displayed a strong neutrophil infiltrate adjacent to the live adult worms. In contrast, in patients treated with doxycycline to eliminate the endobacteria from O. volvulus and to render the worms sterile, the neutrophil accumulation around live adult filariae was drastically reduced. Neutrophils were absent in worm nodules from the deer filaria Onchocerca flexuosa, a species which does not contain endobacteria. Extracts of O. volvulus extirpated from untreated patients showed neutrophil chemotactic activity and in addition, induced strong TNF-alpha and IL-8 production in human monocytes, in contrast to filarial extracts obtained after doxycycline treatment. Thus, neutrophil chemotaxis and activation are induced directly by endobacterial products and also indirectly via chemokine induction by monocytes. These results show that the neutrophil response is a characteristic of endobacteria-containing filariae.

Omar MS et al. (1979) Tropenmed Parasitol "Some observations on onchocerciasis including sowda in the Yemen Arab Republic."

Franz M, Omar MS, Buttner DW

[Tropenmed Parasitol, 1979]

A pilot study on onchocerciasis and sowda was carried out in the south-western region of the Yemen Arab Republic. Of 61 persons examined in eight villages 35 (= 57%) were found positive for microfilariae by the skin-snip method, 13 had typical manifestations of sowda, 17 had other onchocercal-suggestive skin lesions and five had subcutaneous nodules. A single larva of Simulium damnosum s.I. was collected in Wadi Barakani. Numerous larvae and pupae of S. ruficorne and S. hargreavesi were taken in fast-flowing streams in four localities. The examination of microfilariae and adult worms by scanning electron microscopy as well as the histochemical staining of microfilariae for the demonstration of acid phosphatase activity confirmed that the concerned filaria belongs to the species Onchocerca volvulus. No morphological differences could be detected between the smaller number of the examined worms from the Yemen and the extensive parasite material from Liberia, West Africa.