Schistosoma haematobium: histochemistry of glycogen, glycogen phosphorylase a and glycogen branching enzyme in niridazole-treated females.

The body posterior to the ovary of Schistosoma haematobium females was investigated. Glycogen, glycogen phosphorylase a (EC 2.4.1.1) and glycogen branching enzyme (EC 2.4.1.18) activities were detected in the subtegumental muscle system, parenchyma and mature vitelline cells, whereas no activities were detected in the tegument and immature vitelline cells of the parasite. Administration of a single niridazole dose of 250 mg kg-1 to the pouched mouse (Saccostomus camestris) produced the following changes in S. haematobium females: a relatively rapid depletion of glycogen stores due to disruption of the absorptive surface of the parasite, and to an increase in the activity of glycogen phosphorylase a; a reduction in the phosphorylase a to phosphorylase b-conversion capacity of glycogen phosphorylase phosphatase (EC 3.1.3.17); a decrease in glycogen branching enzyme activity; and a relatively rapid degeneration of parasite cells possibly due to their loss of endogenous energy reserves.     

Schistosoma haematobium: Amoscanate and adult worm ultrastructure

Amoscanate, when administered orally as an aqueous or “formulated” preparation, induced pronounced ultrastructural abnormalities in male and female Schistosoma haematobium. Higher dose levels of the aqueous suspension (300 mg/kg body wt) had to be administered to achieve the full range of effects induced by formulated doses of 2.5–8 mg/kg body wt. Worms were recovered from hamsters between 1 and 120 hr after treatment. Although the amount of amoscanate-induced damage varied considerably between worms, an overall pattern of damage emerged. Initially, 1 hr after treatment, amoscanate caused tegumental vacuolation and oedema. As the drug treatment period was extended to 24 hr, blebbing, exudation, collapse of sensory organelle bases, and abnormal mitochondria became increasingly evident. With exposure to higher drug doses (50–300 mg/kg body wt), the tegument became further distorted with the appearance of necrotic structures and myelin whorls, which appeared to represent various stages in lysosomal formation and digestion. Eventually, erosion of surface layers resulted in the breakdown of tegumental integrity. The caeca and vitellaria were also adversely affected by drug treatment. Basal vacuolation and the formation of myelin whorls occurred in the gastrodermis. In the mature S4 vitelline cells, coalesced vitelline droplets and myelin whorls were evident.     

Schistosoma haematobium: the effect of Astiban on the cell composition and ultrastructure of the vitelline gland and the ultrastructure of the tegument and gastrodermis

Treatment of Schistosoma haematobium (Nigerian strain) in hamsters with a single dose of 40 mg/kg of Astiban caused a reduction in the number of S1, S2, and S3 vitelline cells and an increase in S4 cells. Following seven daily doses of the drug, a marked reduction in S1 cells and a complete loss of S2 and S3 cells occurred such that 95% of the cells were S4 cells, all of which were structurally abnormal. Coagulation and disintegration of the protein granules of the vitelline droplets occurred with increase in lipid droplets, swelling of the nuclear membrane and an increase in cytosegresomes. Blebbing of the tegument in both sexes occurred following a single treatment and vacuolation of the basal infolds and alterations to the mitochondria also resulted, but severe erosion of the tegument was rare even following repeated drug treatment. Damage to the gastrodermis was severe with the development of autophagic vacuoles containing whorls of myelin and sequestered portions of damaged tissue. The degree of damage increased with the number of drug treatments.     

Schistosoma haematobium: the pathology of experimental infection

The pathologic changes in experimental animals infected with Schistosoma haematobium are reviewed and compared to the pathology in infected humans. The clinically important lesions in persons infected with S. haematobium are generally confined to the urogenital system. In experimental animals, functionally important lesions of the urogenital system are the exception but do occur in a significant proportion of infected primates. The acute lesions of the urinary tract in primates are similar to those in infected persons. Chronic lesions characterized by the extensive submucosal accumulation of calcified eggs are common in infected humans but uncommon in S. haematobium-infected animals.     

Observations on morphology and hydrolytic enzyme histochemistry of excysted metacercariae of Himasthla rhigedana (Trematoda: Echinostomatidae)

The morphology of in vitro excysted metacercariae of Himasthia rhigedana was studied by light microscopy, enzyme histochemistry, and scanning electron microscopy (SEM). The body surface is covered with longitudinal rows of pointed spines which extend from the anterior end to just below the acetabulum. Histochemical methods for acid and alkaline phosphatases, β-glucoronidasc, leucine aminopeplidase, nonspecific esterase, acetylcholinesterase, butyrylcholincsterase, chymotrypsin-like protease, α-galactosidase and β-galactosidase were applied to the excysted metacercariae. Certain systems of the metacercaria containing these enzymes showed positive reactions to the appropriate methods and were selectively visualized. Reactions for alkaline phosphatase occur throughout most of the excretory system while acid phosphatase occurs in the gut, oral, and ventral suckers. Reactions for nonspecific esterases and cholinesterascs are found throughout the nervous system, in the gut, and in the oral and ventral suckers. The results of including specific inhibitors or activators in the incubation medium after preineubation m 10^?5m diethyl p-nitrophenyl phosphate (E-600) suggested that A-and C-typc esterases are present in the gut. Inclusion of 10^?4m eserine in the incubation medium abolished cholinesterase activity in the nervous system.     

Ultrastructure and histochemistry of the metacercarial cyst of Spelotrema nicolli (Microphallidae: Trematoda)

Based on electron microscopy and histochemical tests, four layers are described for the metacercarial cyst of Spelotrema nicolli. The outermost layer I is made up of host connective tissue. Layer II, which may contain lipid, is a narrow band varying in electron density. Layer III is composed of mucoprotein with a granular fine structure. The innermost layer is made up of columnar, proteinaceous crystals, which radiate out from the inner edge of the cyst. Observations on the epidermis of Spelotrema nicolli contrast previous work on the mechanism of cyst formation in microphallids.     

Microscopic analysis and seasonality of gemma production in the freshwater red alga Hildenbrandia angolensis (Hildenbrandiales, Rhodophyta)

The development and release of the unique vegetative propagules of the freshwater encrusting alga Hildenbrandia angolensis Welwitsch ex West et West, gemmae, were studied using several different microscopic and histochemical techniques. In addition, the seasonality of gemma production was monitored bimonthly over a 12‐month period in two spring‐fed streams in Texas, USA. Gemmae differentiate within the thallus and are subsequently released from the surface of the crust. Release of the gemmae most likely occurs by digestion of surrounding cells, as suggested by the presence of starch granules and lipid globules in the region between the released gemma and the thallus. The initial separation of the gemmae from the thallus occurs from the sides of the gemma or the bottom, or possibly simultaneously. Contrary to previous studies, we have observed that gemma production occurs endogenously within the thallus of freshwater Hildenbrandia, rather than on the surface of the crust in raised structures. Histochemical tests and electron microscopic examination indicate that the cells of the gemmae contain a large amount of floridean starch. The starch granules frequently form rings surrounding the nuclei of both gemma and thallus cells; a feature infrequently reported for florideophyte red algae. Our seasonality investigations indicate that large fluctuations in gemma production occur over 1 year, but at least some gemma production continues year‐round in the streams examined.     

Schistosoma haematobium: analysis of eggshell protein genes and their expression

Eggshell protein genes of Schistosoma mansoni that encode a 14 kDa protein have been shown to be highly conserved and expressed in a sex-, tissue-, and temporal-specific manner. To initiate studies on the eggshell protein genes of S. haematobium, a cDNA probe, pSMf 61-46, representing a S. mansoni eggshell protein mRNA was used to screen a S. haematobium genomic library. Of the seven independent recombinant clones isolated, two (lambda SH 2-1 and lambda SH 6-1) were analyzed and compared to those of S. mansoni. lambda SH 2-1 and lambda SH 6-1 each contain a different genomic copy of the gene encoding a 19.8 and 17.6 kDa protein, respectively. This is due to an additional 78 bp present in the coding region of lambda SH 2-1 relative to lambda SH 6-1. The rest of the coding sequences are identical, and the 5' and 3' untranslated regions are nearly identical. The deduced amino acid sequences of S. haematobium eggshell proteins are very rich in glycine (47 and 50%) when compared to 43.5% glycine in the protein encoded by S. mansoni. Long stretches of glycines, as many as 15 in a row, occur in the S. haematobium sequence. DNA comparison of the eggshell protein genes of the two schistosome species yielded an overall homology of 83.1%. The homology is much higher in the 5' and 3' untranslated regions than in the protein-coding regions. Genomic clones of both species contained second open reading frames, which appeared to be kept open as a consequence of the amino acid composition of the other. There are no introns in S. haematobium or S. mansoni eggshell protein genes, and the genomic Southern data indicated a similar arrangement of these genes in the genome of both species. Primer extension experiments and dideoxynucleotide sequencing of the RNA determined the mRNA cap site sequence as ATCAT and ATCAC in lambda SH 2-1 and lambda SH 6-1, respectively. Northern blot analysis determined the size of the mRNA to be about 1.0 kp. Expression of the RNA from these genes appears to be regulated in a manner similar to the corresponding genes in S. mansoni. mRNA is found only in mature females and first appears at 70 days after infection of hamsters. DNA sequence comparisons of the 5' flanking regions of S. haematobium and S. mansoni eggshell protein genes to each other and to those of silkmoth and Drosophila revealed several short sequence elements that are shared.(ABSTRACT TRUNCATED AT 400 WORDS)     

Enzyme, Lectin and Immunohistochemistry of Plastic Embedded Undecalcified Bone and other Hard Tissues for Light Microscopic Investigations

Enzymes and tissue antigens were localized on plastic embedded undecalcified bones and teeth using Technovit 7200 VLC (Kulzer, Germany). This resin is hard enough for cutting and grinding procedures on rotating plates with diamond layers. The pores between the diamond grains are not obstructed with this resin. The procedure described here permits localization of antigens in the soft tissues adjacent to, or in the biological hard tissues themselves and in dental implants (ceramic or metallic) on the light microscopic level. The undecalcified bone is fixed and embedded in plastic and cut at 100-150 μm. The slices are ground automatically by a grinding machine to a thickness of 5-10 μm. After application of the substrates for alkaline and acid phosphatases and the required dyes, the distribution of these enzymes can be demonstrated. Tissue antigens also can be detected with slightly modified standard techniques of immunohistochemistry and lectin histochemistry using the peroxidase technique or fluorescence microscopy.     

茴香砂仁种子的解剖学和组织化学研究

茴香砂仁种子的假种皮膜质,由内、外表皮及其间的数层薄壁细胞构成,种皮黑褐色,由外种皮、中种皮和内种皮组成,外种皮为1层表皮细胞;中种皮由1层细胞的下皮层,1层细胞的半透明细胞层、3-4层薄壁细胞的中种皮薄壁细胞层和1层细胞的色素细胞层组成,内种皮由1层径向延长的细胞构成,内切向壁与部分径向壁非常增厚,种子珠区分化出珠孔领,孔盖和珠孔区薄壁细胞,合点区内种皮出现缺口,缺口间的合点区色素细胞群整体轮廓呈刺叭状,珠孔端的则为1层细胞,细胞内含蛋白质、多糖、脂类物质,胚含量脂类物质,还含有蛋白质与多糖。     

距药姜种子解剖学和组织化学研究

距药姜种子解剖学和组织化学研究表明,种子包括种皮、外胚乳、内胚乳和胚。外皮由1层表皮细胞构成,细胞壁纤维素质且明显增厚,中种皮可分为1层细胞的下皮层、半透明细胞层和2-4层细胞的色素细胞层,下皮层和色素细胞层的细胞内充满棕红色色素;内种皮由1层砖形薄壁细胞构成。珠孔区有珠孔领和孔盖的分化,但珠孔领分化不完善。合点区内种皮出现缺口,缺口间充满合点区色素细胞,其整体轮廓成新月形。外胚乳细胞壁平直,细胞内充满淀粉。内胚乳可分为多细胞区简细胞区两部分,内胚乳细胞界限不清,内含物主要是蛋白质,胚少有分化,含脂类、蛋白质、多糖,另外,还对姜花族的种子解剖学特征进行了初步的系统学分析。     

Safranin and Anilin Blue with Delafield's Hematoxylin for Staining Cell Walls in Shoot Apexes

The following technic is suggested for staining cell walls in shoot apexes: After the usual preliminary steps through 50% ethyl alcohol, stain in 1 % safranin 0 for 24 hours. Rinse in tap water and place in 2% aqueous tannic acid for 2 minutes. After rinsing in tap water, stain for 2 minutes in 1 part Delafield's hematoxylin to 2 parts distilled water and rinse in tap water. Remove excess hematoxylin with acidified water (1 drop cone. HC1 in 200 ml. water), then place slides in 0.5% lithium carbonate for 5 minutes. Dehydrate through an ethyl alcohol series, then transfer from absolute alcohol to a saturated solution of anilin blue in “methyl cellosolve” for 5-10 minutes. Wash in absolute alcohol, rinse in a solution of 25% methyl salicylate, 33% xylene, 42% absolute ethyl alcohol and clear for 10 minutes in a solution of 2 parts methyl salicylate, 1 part xylene, 1 part absolute ethyl alcohol. Transfer through two changes of xylene and mount in “clarite” or suitable alternate. The resulting preparations will have clearly defined, dark-staining cell walls and will photograph well when “Super Panchro-Press, Type B” film (Eastman Kodak Co.) is used in conjunction with suitable Wratten filters.     

Schistosoma haematobium in Bulinus guernei: Electron microscopy of hemocyte-sporocyst interactions

Electron microscopy has revealed that in Bulinus guernei (Gambian strain) snails infected with Schistosoma haematobium (Egyptian strain) daughter sporocysts and cercariae, two kinds of hemocytes called granulocytes and hyalinocytes are found associated with the sporocysts. Granulocytes are small, numerous, plumbophilic, and amoeboid. They contain lysosome-like granules. Hyalinocytes are large, sparse, less plumbophilic than granulocytes, and have intracellular microfilaments (about 9 nm wide), and few or no pseudopods. They are devoid of lysosome-like granules. Granulocytes and hyalinocytes infiltrate near sporocysts, but only granulocytes interact with sporocyst microvilli by contact. Granulocytes induce a restricted multilamellated encapsulation reaction. Extracellular microfilaments (about 12.5 nm wide), with a regular transverse structure pattern of about 50-nm periodicity, frequently are found along the outer surface of granulocytes located adjacent to sporocysts. Intracellular filamentous structures and a prominent glycocalyx also are features of the seemingly more active granulocytes contiguous with sporocysts. Cell adhesions may occur between surfaces of (1) granulocytes and sporocysts, (2) interdigitating pseudopodial processes of capsular granulocytes, and (3) granulocytes and hyalinocytes.     

Schistosoma mansoni: ultrastructure of cercarial escape glands

While in the sporocyst, the cercaria of Schistosoma mansoni has a pair of unicellular escape glands whose funduses are located together on one side of the body. The funduses taper into microtubule lined ducts that open on the anterior surface of the oral sucker through desmosome supported pores in the immediate vicinity of the ducts of the acetabular glands. The glands contain membrane-bound secretory granules which have a fine medium-dense, homogeneously granular material in their matrices. A large membrane-bound reservoir of granular material, whose texture is similar to that of the secretory granules, is often seen in the cytoplasm of the funduses. In free-swimming cercariae, the ducts in the oral sucker are the only obvious remains of the escape gland.     

Enzyme histochemistry of the mesocoxal muscles of Periplaneta americana

Histochemical techniques have been employed to characterize enzymatic activity in the mesocoxal muscles of the cockroach, Periplaneta americana. Through our studies of the enzymes myosin-ATPase, NADH reductase, succinic dehydrogenase (SDH), and lactic dehydrogenase (LDH), we were able to classify fibers within these muscles according to criteria established for muscle fibers of vertebrates. Many of the mesocoxal muscles possess two different and distinct populations of fibers, whereas the remaining muscles are homogeneous with respect to their constituent fibers. The data presented here indicate biochemical heterogeneity for muscles of differing structural and functional features and possible neurotrophic influences upon oxidative enzymes and myosin-ATPase isozymes.     

High Genetic Variability of Schistosoma haematobium in Mali and Nigeria

Schistosoma haematobium is one of the most prevalent parasitic flatworms, infecting over 112 million people in Africa. However, little is known about the genetic diversity of natural S. haematobium populations from the human host because of the inaccessible location of adult worms in the host. We used 4 microsatellite loci to genotype individually pooled S. haematobium eggs directly from each patient sampled at 4 endemic locations in Africa. We found that the average allele number of individuals from Mali was significantly higher than that from Nigeria. In addition, no significant difference in allelic composition was detected among the populations within Nigeria; however, the allelic composition was significantly different between Mali and Nigeria populations. This study demonstrated a high level of genetic variability of S. haematobium in the populations from Mali and Nigeria, the 2 major African endemic countries, suggesting that geographical population differentiation may occur in the regions.