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.

Franz M (1988) Trop Med Parasitol "The morphology of adult Onchocerca volvulus based on electron microscopy."

Franz M

[Trop Med Parasitol, 1988]

The fine structures of male and female O. volvulus are described. The sexual dimorphism and the age dependent modifications are mentioned in particular. The cuticle of the male worm consists of more layers than that of the female. The epicuticle of the male is wrinkled, whereas the epicuticle of the female forms protuberances. The outer membrane of the hypodermis is folded to form lamellae, which are associated with a layer of mitochondria. The female worms have only small somatic muscle cells. The intestinal cells are filled with concentric spherules, and the intestinal lumen is reduced. Various types of age dependent alterations of the fine structures are observed. The electron density of the cytoplasm changes. The interspace between basal lamina and cell membrane increases, the number of organelles is reduced and specific structures are decomposed whereas the number of granules, vacuoles and lipid droplets increases with age and the laminae and the cuticle thicken. These age dependent modifications might resemble drug induced alterations.

Franz M et al. (1982) Tropenmed Parasitol "Scanning electron microscope study of adult Brugia malayi."

Franz M, Lenze W

[Tropenmed Parasitol, 1982]

The fine structures of the surface of Brugia malayi obtained from Mastomys natalensis are demonstrated by scanning electron microscopy. The head of the parasite is bulbous in shape. The amphidial openings lie beside small elevations. The surface structure of the inner papillae is smooth with a small elevation in the middle. The outer papillae are grooved. the cuticular annulation in the midbody region of the female worm is narrower than that of the male cuticle. In the posterior region of the female worm there are tubercles and in one worm a lateral papilla was found near the anus. In both sexes the inconspicuous phasmidial openings are situated in a lateral position close to the caudal tip. In the posterior region of the male worm there is an area with tubercles, the area rugosa and numerous perianal and caudal papillae, which vary in their number and distribution. The surface structures are very similar to those of Brugia pahangi.

Franz M (1982) Tropenmed Parasitol "The fine structure of adult Onchocerca volvulus. II. The intestine and the reproductive system of the male worm."

Franz M

[Tropenmed Parasitol, 1982]

The morphology of the gut and the genital duct of five male worms from Liberia and two male worms at least five years old, from Upper Volta are described. The lumen of the intestine can be distended vesicularly or it can be reduced to a cleft which is filled with microvilli. The intestinal epithelium contains concentric spherules or dense bodies with piles of lamellae. In parts of the intestine of a live worm the cells can be completely disintegrated. The wall of the testis consists of a squamous epithelium which contains numerous dense bodies on the luminal side. The wall of the vas deferens is a squamous or cuboid epithelium which contains glycogen and various particles. In the ejaculatory duct the epithelial cells are linked together by desmosomes at their luminal side. The brownish appearance of some organs under the light microscope is related to the accumulation of iron containing particles.

Franz M (1980) Tropenmed Parasitol "Electron microscope study of the cuticle of male and female Onchocerca volvulus from various geographic areas."

Franz M

[Tropenmed Parasitol, 1980]

Male and female Onchocerca volvulus from Liberia, Upper Volta, Tanzania and Guatemala were examined by scanning and by transmission electron microscopy. In the cuticle of the female a basal, a median and a cortical layer can be differentiated. The outer limitation of the cuticle is an irregularly folded surface membrane. Excluding the anterior region the entire cuticle of the worm is covered by a coat. A regular fine honey-comb structure of the surface is found in the anterior region of the female. The morphology of the mouth, the amphidial openings, the papillae and the vulva, as well as the anus and the phasmidial openings, are presented. The cuticle of the male is also composed of a basal, a median and a cortical layer. The surface membrane shows a regular honey-comb pattern, which covers the entire worm with the exception of the anterior and posterior ends, but no coat was found. The cephalic region looks like that of the female. Papillae are arranged around the anus and the caudal tip. The variability of these papillae regarding their number and distribution is presented. The type of the two spicules and of the canal of the longer one is illustrated. The comparison of the worms from Liberia, Upper Volta, Tanzania and Guatemala revealed no morphological differences. Groups of males were examined statistically for differences of the distribution of the posterior papillae, but no geographical differences could be proven.

Franz M (1982) Tropenmed Parasitol "The fine structure of adult Onchocerca volvulus. I. The cuticle, the hypodermis and the muscle cell of the male worm."

Franz M

[Tropenmed Parasitol, 1982]

The fine structure of the cuticle, the hypodermis and the muscle cells of five male worms from Liberia and of two male worms, at least five years old, from Upper Volta is described. The cuticle in the lateral regions is thicker and consists of more layers than in the dorsal and ventral regions. The innermost zone of the hypodermis contains a wide labyrinth of extracellular clefts. The muscle cells are of the shallow coelomyarian type. Bacteria were found in the hypodermis of worms from Liberia and Upper Volta. The hypodermis and the muscle cells contained various other inclusions and particles. Some of them were formed by aggregations of regularly arranged membranes and lamellae. Although all the worms had been alive at the moment of fixation, severe degenerative alterations of the hypodermis and the muscle cells could be observed. Only the cuticular morphology was more or less constant in all seven worms.

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. 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. (1990) Parasitol Res "Fine-structure alterations in female Brugia malayi and Litomosoides carinii after in vivo treatment with flubendazole."

Franz M, Benten P, Zahner H

[Parasitol Res, 1990]

Female filariae of the species Brugia malayi and Litomosoides carinii were investigated by means of electron microscopy after in vivo treatment with flubendazole. The earliest fine-structure alteration in both species was the disappearance of microtubuli from the intestinal cells as soon as 6 h after treatment. There was no further disintegration of intestinal cells for several days. Microtubuli disappeared from the outer zone of the hypodermal cytoplasm 24 h after treatment. At this time, marked alterations were also observed in the oogonia and in the embryonic cells. Many of these were swollen; their nuclear envelope was partly resolved and the chromatin was condensed, but no spindle apparatus was formed. The early fine-structure alterations observed after in vivo treatment with flubendazole consisted of the disappearance of microtubuli from various tissues. This led to the interruption of cell division in oogonia and embryonic cells and, and subsequently, to the disintegration of most other filarial tissues. These morphological alterations differed considerably from those observed after treatment with benzothiazole derivatives, which do not affect the microtubuli of the filariae.

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.