Heidi Dolder

Testis response to low doses of cadmium in Wistar rats

Although it is well known that cadmium (Cd) causes adverse effects on male rat reproductive organs, few studies have quantified alterations caused by its low doses. Quantification of these alterations, especially in the testis, was measured using morphometry. A single dose of cadmium chloride (1 or 1.2 mg/kg BW) was injected i.p. in adult rats, killed after 7 or 56 days. The lower dose caused slight alterations as measured by morphometrical analysis. The higher dose caused significant reduction in testis and epididymis weight, gonadossomatic index and length of seminiferous tubule (ST) after 7 and 56 days. Cadmium significantly reduced the ST diameter after 56 days. Decreased volume density of ST, after 7 and 56 days, was accompanied by an increase in interstitium volume density. The damage caused by the dose of 1.2 mg/kg can be clearly observed with light microscope. After 7 days, the tubule lumens were filled with degenerated germ cells and multinucleated spermatid aggregates. Vacuolization of the seminiferous epithelium was also observed. After 56 days, increased damage resulted in vacuolated ST, consisting only of Sertoli cells. Scanning electron microscopy examination of the testis showed that, in the group cadmium treated (1.2 mg/kg) and killed after 56 days, the interstitial tissue presents a compact and fibrous appearance with absence of fenestrae. The seminiferous epithelium height diminished and the absence of spermatozoa can be noted. The results show that a very small difference of Cd dose causes a sudden increase in testicular damage, apparently overpowering this tissue’s natural defences.

Antioxidative and in vitro antiproliferative activity of Arctium lappa root extracts.

BackgroundArctium lappa, known as burdock, is widely used in popular medicine for hypertension, gout, hepatitis and other inflammatory disorders. Pharmacological studies indicated that burdock roots have hepatoprotective, anti-inflammatory, free radical scavenging and antiproliferative activities. The aim of this study was to evaluate total phenolic content, radical scavenging activity by DPPH and in vitro antiproliferative activity of different A. lappa root extracts.MethodsHot and room temperature dichloromethanic, ethanolic and aqueous extracts; hydroethanolic and total aqueous extract of A. lappa roots were investigated regarding radical scavenging activity by DPPH, total phenolic content by Folin-Ciocalteau method and antiproliferative in vitro activity was evaluated in human cancer cell lines. The hydroethanolic extract analyzed by high-resolution electrospray ionization mass spectroscopy.ResultsHigher radical scavenging activity was found for the hydroethanolic extract. The higher phenolic contents were found for the dichloromethane, obtained both by Soxhlet and maceration extraction and hydroethanolic extracts. The HRESI-MS demonstrated the presence of arctigenin, quercetin, chlorogenic acid and caffeic acid compounds, which were identified by comparison with previous data. The dichloromethane extracts were the only extracts that exhibited activity against cancer cell lines, especially for K562, MCF-7 and 786-0 cell lines.ConclusionsThe hydroethanolic extracts exhibited the strongest free radical scavenging activity, while the highest phenolic content was observed in Soxhlet extraction. Moreover, the dichloromethanic extracts showed selective antiproliferative activity against K562, MCF-7 and 786-0 human cancer cell lines.

Antispermatogenic effect of Achillea millefolium L. in mice

The effect of an ethanolic extract (200 mg/kg/day, intraperitoneally, for 20 days) and a hydroalcoholic extract (300 mg/kg/day, orally, for 30 days) of Achillea millefolium L. (yarrow) flowers on the spermatogenesis of Swiss mice was studied by evaluating morphologic characteristics with the light and electron microscopes. The alterations observed were exfoliation of immature germ cells, germ cell necrosis, and seminiferous tubule vacuolization. Animals treated with the extracts had an increased number of metaphases in the germ epithelium that might be due to cytotoxic substances or substances stimulating cell proliferation.

Ultrastructural characteristics of the spermatozoa of Scelionidae (Hymenoptera, Platygastroidea) with phylogenetic considerations

The Scelionidae sperm are distinguished from those of all hymenopterans already studied at least by the presence of a single mitochondrial derivative and the absence of a centriolar adjunct. The absence of an acrosome, in Telenomus podisi, is also unique. The helical nucleus and mitochondrial derivative spiralling around a twisted axoneme can be considered as synapomorphies shared with the Chalcidoidea, and the mitochondrial derivative running together with the nucleus for a long distance can be considered as a synapomorphy shared with the Diapriidae. Therefore, from a consideration of these features, it is possible to suppose that the Scelionidae, Chalcidoidea and Diapriidae are more closely related between themselves than are any of them to the Cynipoidea, since the latter does not share any of the above‐mentioned features. This supposition agrees with phylogenetic analyses that supported the inclusion of Platygastroidea (Scelionidae and Platygastridae) and Chalcidoidea within the Proctotrupomorpha lineage, as well as the close relationship of these to the Diapriidae, and the exclusion of the Cynipoidea from this lineage.

Sperm structure and ultrastructure of the fire ant Solenopsis invicta (Buren) (Hymenoptera, Formicidae).

The spermatozoa of Solenopsis invicta are long and slender, measuring about 70 microm in length, of which the head region measures approximately 13 microm. The head consists of an acrosome formed by an acrosomal vesicle covering a perforatorium and a nucleus. This latter measures about 12 microm, has compact chromatin, and many translucent areas. The flagellum consists of an axoneme of 9+9+2 microtubules that begins just below the nuclear base. The two mitochondrial derivatives are of almost equal diameter, and there are two accessory bodies. The nucleus is attached to the flagellum by a centriolar adjunct located between the baso-lateral region of the nucleus and the anterior mitochondrial derivative extremities. Therefore, the nucleus-flagellum transition region of the spermatozoa of S. invicta is very similar to that of other ants and differs from the first description of this species [Ann. Entomol. Soc. Am. 67 (1967) 632]. In relation to other aculeates, it is possible that three characteristics (type of centriolar adjunct, presence of paracrystalline areas in each mitochondrial derivative, and the position of these areas within each derivative) may be autopomorphies for the Formicidae.

Effect of Excess Cadmium and Zinc Ions on Roots and Shoots of Maize Seedlings

ABSTRACT The effect of 8-day-old exposure maize seedlings with cadmium (Cd) or zinc (Zn), separately, are described with special attention being given to ultrastructural changes as well as changes of the growth. These elements, frequent pollutants found in the soil, were added as 1 mM solutions to nutrient solution used for roots and shoots of maize seedlings, investigated 8 days after germination. The symptoms of heavy metal toxicity were clear showing that Cd inhibits root growth more strongly than the shoots and more effectively than zinc ions. The results of scanning electron microscopy revealed changes in the leaf surface, particularly in the guard cells of the stomata. The ultrastructural analyses of the parenchyma mesophyll cells showed extensive chloroplast disorganization, mainly affecting the thylakoid membranes and grana.

Histomorphometric evaluation of the neotropical brown brocket deer Mazama gouazoubira testis, with an emphasis on cell population indexes of spermatogenic yield

Information on the reproductive biology of neotropical cervids is scarce. Therefore, the aim of this study was to perform biometric, histologic and stereologic analyses of the brown brocket deer Mazama gouazoubira testis, with an emphasis on the intrinsic yield and the Sertoli cell index. Seven adult males kept in captivity were used. The animals were immobilized; anesthetized and testicle fragments were obtained by biopsy incision. The material was fixed, processed and examined by routine histological methods for light microscopy. The average body weight was 17.2kg, from which 0.40% were allocated in gonads and 0.33% in seminiferous tubules, which represented 85.9% of the testis parenchyma. The mean albuginea width and volume were 345.7μm and 3.5mL (5.3% of the testicular weight), respectively. The mean mediastinum volume of both testicles was 1.0mL (1.5% of the testicular weight) and the testicular parenchyma volume corresponded to 93.1% of total testicular weight (64.9g). The seminiferous tubules diameter was 224.4μm, while the epithelium height was 69.6μm. On average, an adult brown brocket deer showed a total of 1418m of seminiferous tubules in both testicles (21.5m per gram of testis). Each stage I seminiferous tubular cross section contained 1.10 type A spermatogonia, 13.4 primary spermatocytes in pre-leptotene/leptotene, 13.7 spermatocytes in pachytene, 48.8 round spermatids and 3.7 Sertoli cells. The general yield of spermatogenesis was 44.7 cells and the Sertoli cell index was 13.2. The qualitative and quantitative description of testicular histology of brown brocket deer help to understand its spermatogenic process and to establish parameters for the reproductive biology of this wild species. Furthermore, the data from the present research will help further studies using other species of Brazilian cervids, especially endangered ones, making an additional effort to the species preservation.

Avian anticoccidial activity of a novel membrane-interactive peptide selected from phage display libraries

In the present work, we describe the discovery of PW2, a novel peptide presenting in vitro activity against Eimeria acervulina and E. tenella sporozoites. PW2 was selected from phage display (Ph.D.) peptide libraries by an alternative method of panning using living purified E. acervulina sporozoites as targets. Our results showed that the peptide disrupts the sporozoite pellicle, resembling the effect caused by most natural antimicrobial peptides. PW2 peptide was also effective against fungi and showed low activity against Toxoplasma gondii tachyzoites, but no activity against Trypanosoma cruzi, Crithidia fasciculata epimastigotes, and bacteria. Additionally, the parasiticidal concentrations of PW2 produced a very low lytic effect on mammalian and avian cells. The effectiveness against Eimeria sporozoites and the absence of adverse effects to host cells indicates that PW2 may be used as a model to generate new drugs for the control of avian coccidiosis.

Heteropterys aphrodisiaca infusion reduces the collateral effects of cyclosporine A on the testis.

Cyclosporine A (CsA) is known to have testicular toxicity, leading to male infertility. Stimulant and aphrodisiac properties have been attributed to the plant, Heteropterys aphrodisiaca. Thus, the present work was undertaken to evaluate the association of the drug and the medicinal herb in Wistar rats, applying testicular morphometry and ultrastructure. Twenty‐four rats were used, divided into four groups: I, control; II, CsA; III, simultaneous use of CsA and H. aphrodisiaca; IV, H. aphrodisiaca. Daily administration by gavage was carried out, during 56 days, of water (sham), CsA in a dose of 15 mg/kg per day and/or H. aphrodisiaca in a dose of 0.5 ml of the infusion prepared with 25 g of roots/100 ml of boiling water. Increased body weight was observed for all groups, but the animals that received only CsA showed the smallest body weight gain. Morphometry showed increased connective tissue volumetric proportion and decreased Leydig cell volumetric proportion in CsA‐treated rats. Using transmission electron microscopy, it was possible to ascertain that CsA caused seminiferous epithelium degeneration, resulting in Sertoli cell vacuolization, abnormal round and elongated spermatids and large accumulation of residual cytoplasm at the epithelium border next to the lumen. Expanded intercellular spaces between germ cells were still observed in H. aphrodisiaca‐treated rat testes. The administration of H. aphrodisiaca infusion to CsA‐treated rats diminished nearly all the CsA‐induced damage to the testis ultrastructure, suggesting that H. aphrodisiaca infusion may be used combined with CsA to reduce CsA‐induced injuries in the testis. Anat Rec, 291:809‐817, 2008.

Ultrastructural characterization of spermatozoa in euglossine bees (Hymenoptera, Apidae, Apinae)

Summary.Euglossine spermatozoa are the longest described to date for the Hymenoptera. This cell includes a head and a flagellar region. In transverse sections, the acrosome is circular at the tip but has an oval contour along most of its length. The perforatorium penetrates into a deep cavity in the nuclear tip. The flagellum consists in an axoneme, a pair of mitochondrial derivatives, a centriolar adjunct and a pair of accessory bodies. The axoneme has a 9+9+2 microtubule pattern which becomes gradually disorganized in the final portion, with the central microtubules and the nine doublets terminating simultaneously, followed by the accessory microtubules. The mitochondrial derivatives are asymmetric both in length and diameter. Sectioned transversally, the derivatives are ellipsoidal or have a pear shape. The larger one has a more obvious paracrystalline region. The centriolar adjunct begins at the nuclear base and extends parallel to the axoneme until it encounters the smaller mitochondrial derivative, on which it fits, making a concave groove. In addition to these consistent euglossine features, species-specific differences that might be useful in phylogenetic work on the group are also noted.