Genesis of spermatodesms in Tylopsis liliifolia (Orthoptera: Phaneropterinae) and their transit in the male genital tract.

The spermatodesms of Tylopsis liliifolia form in the most proximal follicular cysts and are composed of a large number of sperm held together by a cap located in the anterior region of the acrosome. The cap is formed by short thin fibrils, loosely arranged at random, probably derived from secretory activity of cells of the cyst wall. Compared to other Tettigoniidae, a peculiar feature is acrosomal wings that twist gradually around the anterior region of the nucleus; at the end of the twisting process, the region of the sperm acrosome, observed in cross section, shows a typical spiral form. Spermatodesms do not undergo any substantial changes in the spermiduct. The epithelial cells of the wall have secretory activity and many show marked spermiophagic activity, which is conducted by epithelial cell protrusions that envelop the gametes, taking them into the cytoplasm. When removed from seminal vesicles and observed in vivo, spermatodesms show accentuated corkscrew movement, and when observed by SEM, slight torsion. Thus organized, spermatodesms are transferred to the spermatophore during mating, where they are transformed before reaching the seminal receptacle.

Formation and rearrangement of spermatodesms in males of some Orthoptera Tettigoniidae.

In the male genital tract of Tettigoniidae, the spermatodesms are composed of a limited number of spermatozoa whose nuclei and acrosomes are covered by a mucous cap. The formation of the cap begins in the testicular cyst during the lengthening of the apical prolongations of the spermatids and the spermatids' simultaneous division into small bundles or spermatodesms. The cap material is formed from a loosely arranged material in the lumen of the cyst, probably produced by the secretory activity of the delimiting cells. Another characteristic aspect of the Tettigoniidae is the rearrangement of the cap inside the spermiduct that seems to start when material from the lumen of the organ enters from the basal part of the cap. Except for the fibrils of the peripheral lamina, the fibrils of the cap undergo a marked degradation process. The final organization of the spermatodesm cap is reached inside the seminal vesicles; it consists of the fibrillar peripheral lamina delimiting an interior made up of loosely arranged fibrils immersed in a finely granular matrix.

Prothrombin A19911G polymorphism and the risk of venous thromboembolism.

BACKGROUND: The A > G polymorphism at position 19911 of the prothrombin gene is associated with increased plasma prothrombin levels but its role as a risk factor for venous thromboembolism (VTE) is not established. OBJECTIVE: To investigate the role of prothrombin 19911 A > G polymorphism in the risk of VTE in patients with heterozygous prothrombin 20210GA or factor (F) V Leiden and in those without thrombophilia. PATIENTS AND METHODS: Case-control study of 793 patients with prothrombin 20210 GA (n = 167) or FV Leiden (n = 198), and without thrombophilia (n = 428), and of 795 healthy individuals with the corresponding coagulation profile, investigated for the presence of prothrombin 19911 A > G. Plasma prothrombin levels were measured in 342 individuals. RESULTS: Prothrombin 19911 A > G did not increase the risk of VTE in carriers of prothrombin 20210 GA [odds ratio (OR) 1.2, 95% CI (95% CI) 0.8-1.8] but significantly increased the risk in carriers of FV Leiden (OR 2.1, 95% CI 1.3-3.4) and in patients without thrombophilia (OR 1.5, 95% CI 1.0-2.2). Higher plasma prothrombin levels in carriers of prothrombin 19911 A > G polymorphism than in non-carriers were found among individuals without thrombophilia (P =0.05) and with FV Leiden (P = 0.07), but not in carriers of prothrombin 20210 GA (P = 0.2). CONCLUSIONS: Prothrombin 19911 A > G polymorphism was independently associated with a 1.5-fold increased risk of VTE and increased 2-fold the risk of VTE associated with FV Leiden, both increases statistically significant. No effect was observed in carriers of prothrombin 20210 GA, perhaps because this polymorphism has a stronger influence on plasma prothrombin levels than the prothrombin 19911 polymorphism.

Role of male accessory glands in spermatodesm reorganization in Orthoptera Tettigonioidea.

A preliminary examination of the spermatodesms of Orthoptera Tettigonioidea revealed a structure that is similar in individuals of the same sex but very different in specimens of opposite sex. This reorganization would seem to take place inside the spermatophore during transit from the male to female genital tracts. The results of incubating spermatodesms with the secretions of glandular extract (GE) obtained from male accessory glands, known to be involved in forming the spermatophore wall, revealed changes in the spermatodesm 'cap' that are comparable to those occurring in vivo. Moreover, incubation of spermatodesms with the extracts obtained separately from tubules of the 1st and 2nd orders (GE1, GE2) established that GE2 alone modifies the spermatodesms, thus excluding the possible implication of 1st order tubules in the rearrangement process. In conclusion, data from incubations of spermatodesms with the single fractions obtained by submitting GE2 to gel-filtration FPLC show that only the peak 4 maintains intact the biological activity of GE2, SDS-PAGE analysis of the fraction corresponding to peak 4 revealed a greater protein content of 29 kD, which also appears to a lesser degree in fraction 3. This material is responsible for a partial dismantling of the 'cap' in the incubated spermatodesms.

Correlation between family history of hypertension and haemostatic disorders.

BACKGROUND: The aim of this study was to evaluate whether a family history of hypertension is associated with haemostatic disorders. METHODS: In 38 normotensive subjects with a family history of hypertension (relatives) and in 46 sex, age and body mass index matched controls with no family history of hypertension, tissue-type plasminogen activator (t-PA), plasminogen activator-inhibitor (PAI-1), D-dimer (DD) and prothrombin fragment 1+2 (F1+2) were evaluated. RESULTS: The t-PA and PAI-1 observed values were significantly higher than the values detected in the controls. CONCLUSIONS: These data seem to suggest a correlation between family history of hypertension and haemostatic disorders.

Structure of spermatodesms of Orthoptera Tettigonioidea.

Examination of spermatodesms collected from the male and female genital tracts of numerous Orthoptera Tettigonioidea revealed an overall morphological and ultrastructural organization that is generally similar in individuals of the same sex but considerably different between males and females of even the same species. In the male genital tracts each spermatodesm is composed of a limited number of spermatozoa whose nuclei and acrosomes are covered by a mucous cap. The spermatozoa inside each bundle are mainly arranged in parallel rows and are always distinctly separate. The number of spermatozoa per spermatodesm may vary within the same individual although it does not seem to exceed a maximum value that we could only determine exactly in Tettigoniidae species. The most characteristic feature of spermatozoa of all the species examined is a conspicuous elongation of the plasma membrane in the acrosomal region that is not present in the female genital tracts. In addition, spermatodesms from females are composed of highly numerous tightly packed spermatozoa that are linked together via the acrosomal region. This characteristic of spermatodesms, never previously reported in other insect species, would involve their reorganization during transfer from the male to the female genital tracts and would seem to take place in the spermatophore. The probable role of spermatodesms in the reproductive physiology of Tettigonioidea might be related to the degree of maturity of the sex cells transferred to the female; the reorganization of the spermatozoa out of the male genital tracts seems to support this hypothesis.

Ultrastructural organization of seminal receptacle and sperm storage in Porcellio laevis latreille (crustacea: Isopoda oniscidea).

The seminal receptacle of Porcellio laevis is a specialized region of the genital tract placed at the confluence of the oviduct with the ovary. In virgin sexually mature females the seminal receptacle wall consists of a monolayered epithelium lying on a thin basal lamina and delimiting a narrow and anfractuous lumen. The cells are joined by cell junctions only in their apical portion and do not show marked secretory activity; numerous cells appear to undergo a partial or complete process of autophagy that preludes a remodelling of the seminal receptacle allowing it to receive and store a conspicuous number of spermatozoa. In mated females epithelial cells are characterized by wide intracellular spaces in their basal region, by an extensive development of smooth reticulum and by the release into the lumen of an abundant lipidic secretion. Some spermatozoa stored in the lumen are captured by pseudopodial-like protrusions produced by the epithelial cell surface and then drawn into cavities that form within the epithelial cells themselves. The spermatozoa stored in the seminal receptacle appeared to be well conserved and apparently able to fertilize even several months after insemination.

Ultrastructural and histochemical characteristics of the lateral oviducts of Baculum thaii Haus. (Phasm.).

The wall of the lateral oviducts of baculum thaii is composed of a monolayered epithelium, lacking a cuticular intima, which lies on a sheath of striated muscular fibres. Untreated oviductal specimens exhibit two distinct regions. The anterior region, into which the various ovarioles emerge, is opalescent. The posterior region is more dilated and darker in colour. On the basis of the ultrastructural characteristics of the epithelial cells, four successive zones are definable for each oviduct. The first two zones comprise the most anterior oviductal area while the third and fourth comprise the posterior region. In zone 1 only is the oviductal wall composed of a single cell type. In addition, differences in structural organization between mated and virgin females were observed in this zone alone. In the three remaining zones, two distinct cell types were distinguishable according to two models of fundamental organization: cells having numerous apical microvilli and dome-shaped cells. The results of histochemical analyses established that the abundant secretory product elaborated by the epithelial cells is rich in both proteins and predominantly acidic mucosubstances. The histochemical characteristics of the secretory product differentiate significantly not only between the four zones in the same individual but also when the corresponding zones are compared in the mated and virgin females.

A convenient method for the preparation of a variety of 13C-substituted D-fructose phosphates using readily available enzymes of the glycolytic pathway.

Methods are presented for the preparation of a variety of D-fructose phosphates, 13C-substituted at any single carbon site or at any two symmetrically disposed carbon sites, from either 13C-substituted pyruvate or L-alanine. It is demonstrated that millimole quantities of product can be obtained in good yield following a "one-pot" incubation of 13C-substituted precursors with commercially available enzymes and cofactors of the glycolytic pathway. Since it has previously been shown that a wide variety of aldehydes serve as acceptable substrates for the final rabbit muscle aldolase-catalyzed condensation step, the method can potentially be applied to prepare a wide variety of 13C-substituted sugars and sugar phosphates.

Lectin binding to the egg envelopes in Eyprepocnemis plorans (Charp.) (Orthoptera, Acrididae).

The distribution of glycoconjugates in the egg envelopes of Eyprepocnemis plorans was investigated using various FITC-conjugated lectins. In the epichorion, the lectins ConA, SBA and WGA each have particular binding patterns, while TPA binding is confined to its deepest regions only. The glycoconjugates of the micropylar wall present different characteristics from those of the surrounding chorion. The vitelline coat shows a marked binding for WGA and TPA only; below the inner micropylar openings, this binding pattern is uniform over the whole extent of the coat and therefore it is not possible to identify specific binding sites for these two lectins. Contrary to what has been observed in some other insect species, the vitelline coat does not seem to be involved in the structural organization of the mycropyles.