Distribution and viability of spermatozoa in the canine female genital tract during post-ovulatory oocyte maturation

Background

Unlike other domestic mammals, in which metaphase-II oocytes are ovulated, canine ovulation is characterized by the release of primary oocytes, which may take 12 to up to 36 hours. Further 60 hours are needed for maturation to secondary oocytes which then remain fertile for about 48 hours. Oestrus takes 7 to 10 days on average and may start as early as a week before ovulation. This together with the prolonged process of post-ovulatory oocyte maturation requires an according longevity of spermatozoa in the female genital tract in order to provide a population of fertile sperm when oocytes have matured to fertilizability. Therefore the distribution and viability of spermatozoa in the bitch genital tract was examined during post-ovulatory oocyte maturation.

Methods

Thirteen beagle bitches were inseminated on the day of sonographically verified ovulation with pooled semen of two beagle dogs containing one billion progressively motile spermatozoa. Ovariohysterectomy was performed two days later (group 1, n = 6) and four days later (group 2, n = 7). The oviduct and uterine horn of one side were flushed separately and the flushing’s were checked for the presence of gametes. The oviducts including the utero-tubal junction and the uterine horns, both the flushed and unflushed, were histologically examined for sperm distribution.

Results

The total number of spermatozoa recovered by flushing was low and evaluation of viability was limited. Prophase-I oocytes were collected from oviduct flushing in group 1, whereas unfertilized metaphase-II oocytes were detected in group 2. From day 2 to day 4 after ovulation a significant decrease in the percentage of glands containing sperm (P<0.05) and a marked reduction of the mean sperm number in uterine horn glands were observed. A concomitant diminution of spermatozoa was indicated in the utero-tubal junction accompanied by a slight increase in sperm numbers in the mid oviduct.

Conclusions

Oocyte maturation to metaphase-II stage is accompanied by a continuous sperm detachment and elimination in the uterine horns. Entrance of spermatozoa into the caudal oviduct seems to be steadily controlled by the utero-tubal junction thus providing a selected sperm population to be shifted towards the site of fertilization when oocyte maturation is completed.     

Gnomonia fragariae, a Cause of Strawberry Root Rot and Petiole Blight

Gnomonia fragariae has been occasionally listed among the fungi associated with diseased strawberry plants. However its pathogenicity has not been established. During the investigation on strawberry decline in Latvia and Sweden, a fungus was repeatedly recovered from discoloured root and crown tissues of severely stunted plants. Attempts to induce sporulation of the isolates grown on several agar media resulted in the formation of mature ascomata only on potato carrot agar and oatmeal agar. On morphological grounds and comparisons with reference herbarium specimens these isolates were identified as Gnomonia fragariae. The pathogenicity of the fungus was evaluated initially in the detached leaf assay and subsequently in three bioassays on strawberry plants. All the bioassays showed that G. fragariae was pathogenic on strawberry and capable of causing severe root rot and petiole blight. The symptoms that developed in the greenhouse experiments closely resembled those observed in the fields. The fungus did not cause rapid plant death but growth and development of inoculated strawberry plants was severely affected. To our knowledge this is the first time when pathogenicity of G. fragariae as a root rot pathogen has been clearly established. Our study shows that G. fragariae is one of the serious pathogens involved in the root rot complex of strawberry in Latvia and Sweden.     

Salicylatreiche Weiden für die Arzneimittelherstellung

The use of salicylate rich willow bark is necessary for the economic fabrication of herbal drugs in the pharmaceutical industry. Natural derived salicylates can be used to medicate fever, rheumatic disturbances or headache. Clones from three willow species Salix daphnoides, Salix pentandra, and Salix purpurea were analysed for their salicylate content. All species showed a distinct salicylate profile. The major salicylate of S.?daphnoides and S.?purpurea was salicortin, whereas the main compound of S.?pentandra was 2′-O-acetylsalicortin. Clones of S.?daphnoides showed the highest mean salicylate content, followed by S.?purpurea and S.?pentandra. The variability within salicylates among species was higher than the clone variability. Also the seasonality of salicylates in willow bark was studied. The analysis revealed that after a peak concentration of salicylates in spring the content decreased during the vegatative season from March to August 2007. The lowest concentration was found August 2007. An increase of the salicylate concentration could be observed from August to October 2007. Specific clone selections and the determination of the optimal harvest time to gain highest salicylate contents are important for the economic fabrication of herbal drugs.     

Insektizide und phytotoxische Wirkung von Steinkohlenflugasche

Zusammenfassung  Im Rahmen eines Umweltgutachtens wurde die phytotoxische und insektizide Wirkung von Steinkohlenflugasche untersucht. Als Testorganismen dienten die Pflanzen Tropaeolum majus (Kapuzinerkresse) und Lepidium sativum (Brunnenkresse) sowie die Vorratsschädlinge Plodia interpunctella (Dörrobstmotte), Tenebrio molitor (Mehlkäfer) und Sitophilus granarius (Kornkäfer). Gezeigt werden konnte, dass die verwendete Steinkohlenflugasche bei einem aus der Literatur entnommenen theoretischen täglichen Flugstaubniederschlag von 1 g/m² keine phytotoxischen bzw. insektiziden Eigenschaften aufwies. Selbst eine zehnfach erhöhte Dosis von 10 g/m² hatte innerhalb von 2 Tagen keine erhöhte Mortalität von Dörrobstmottenlarven bzw. über einen Zeitraum von 12 Tagen keine erhöhte Mortalität von Mehlkäfern (alle Entwicklungsstadien) zur Folge. Für Kornkäfer ergab sich eine leichte Erhöhung der Mortalität auf 2 % innerhalb von 12 Tagen nach einer Dosierung von 5 g/m². Die Mortalitätsrate von Kornkäfern erhöhte sich nach Applikation von 125 mg Flugasche auf eine Fläche von 50 cm² innerhalb von 12 Tagen von 6 % in der Kontrolle auf 14 %. Eine mit Diatomeenerde zur Positivkontrolle durchgeführte Versuchsreihe hatte hingegen bei gleich hoher Dosierung eine 100 %ige Abtötung aller adulten Kornkäfer zur Folge. Starke Pflanzausfälle waren erst bei einem komplett aus Flugasche bestehendem Substrat zu verzeichnen. Nur geringfügig waren die Wuchsleistungen der verwendeten Pflanzen ab einem Flugascheanteil von 50 % im Substrat beeinträchtigt.

Hematologic and physiologic reference ranges for free-ranging adult and young common loons (Gavia immer).

Wild common loons (Gavia immer) were captured across much of their southern North American range. Hematologic and physiologic data were collected to establish reference ranges for adults and chicks from four geographic areas: New England, Canadian Maritimes, south-central Quebec, and the Upper Great Lakes. Mean body mass and blood-glucose levels of adult loons varied among geographic regions. Chicks had lower PCV and total solids than adult loons, and also had faster heart rates and higher blood glucose levels. Although mean body mass in males was consistently greater than in females, hematologic and physiologic reference ranges between sexes were not significantly different. Geographic and age-related differences exist in common loon hematologic and physiologic reference ranges and should be considered when assessing such parameters.     

Abrasive und hydrophil/lipophile Effekte unterschiedlicher inerter Stäube im Einsatz gegen Schadinsekten am Beispiel des Kornkäfers Sitophilus granarius L.

Modern research on the insecticidal effects of inert dusts as a stored-grain protectant and for plant protection purposes began in the 1920s. The main advantage of inert dusts is their low-mammalian toxicity. One group of inert dusts used for pest control is diatomaceous earth (DE). DE has been tested as a whole and evaluated as a Group 3 carcinogen by the International Agency for Research on Cancer (IARC). A Group 3 listing indicates that DE is not classifiable as to its carcinogenicity to humans, since definitive conclusions cannot be drawn from the research conducted to date. DE is a form of naturally occurring amorphous silica that can kill insects by ab/adsorbing the lipids such as waxes and triglycerides of the outer cuticle layer by direct contact. When the thin, waterproof layer is lost, the insect looses water and dies. Desiccation follows Ficks law of diffusion into the surrounding atmosphere. In addition to its desiccant action the theory that DE works abrasively to rupture insect cuticles has been proposed. To evaluate the abrasive effects of DE we have tested 27 inert dusts with different surface properties. Materials were compared based on the time needed to kill 50% (LT₅₀) of Sitophilus granarius weevils in laboratory experiments. Substances with hydrophilic and/or hydrophobe properties were significantly more effective against S.?granarius than substances which are mainly abrasive. There is a strong correlation between LT₅₀ and weight loss (=?water loss) of insects (p?=?0.014). Particle size played only a secondary role (p?=?0.077). Commercial DE formulations and activated charcoal (Carbopal MB4) were the most effective hydrophilic substances tested. The most abrasive substances were corundum and silica sand with small particle sizes. It is concluded, that those materials were effective because of a good coverage of the insects outer cuticle and existing shear stress. All results presented are discussed in context of the insecticidal mode of action of inert dusts and possible registration of silica based formulations as biocide.     

Myofasciitis in the domestic ferret

Since late 2003, an inflammatory disease of muscle and fascia has been diagnosed in several ferrets at Northwest ZooPath, and this report describes the condition in 17 ferrets. It is a disease of young ferrets, characterized by rapid onset of clinical signs, high fever, neutrophilic leukocytosis, treatment failure, and death (or euthanasia). Gross lesions include atrophy of skeletal muscle; red and white mottling and dilatation of the esophagus; and splenomegaly. Histologically, moderate to severe suppurative to pyogranulomatous inflammation is in the skeletal muscle and the fascia at multiple sites, including esophagus, heart, limbs, body wall, head, and lumbar regions. Myeloid hyperplasia of spleen and/or bone marrow also is a prominent feature. Ultrastructural lesions include mitochondrial swelling, intracellular edema, disruption of myofibrils and Z bands. Bacterial and viral cultures, electron microscopy, immunohistochemistry, and polymerase chain reaction were negative for a variety of infectious agents. The clinical presentation and distribution of lesions suggests that polymyositis in domestic ferrets is likely a distinct entity. The etiopathogenesis if this condition is not known.     

Cytoprotective role of Ca2+- activated K+ channels in the cardiac inner mitochondrial membrane

Ion channels on the mitochondrial inner membrane influence cell function in specific ways that can be detrimental or beneficial to cell survival. At least one type of potassium (K+) channel, the mitochondrial adenosine triphosphate-sensitive K+ channel (mitoKATP), is an important effector of protection against necrotic and apoptotic cell injury after ischemia. Here another channel with properties similar to the surface membrane calcium-activated K+ channel was found on the mitochondrial inner membrane (mitoKCa) of guinea pig ventricular cells. MitoKCa significantly contributed to mitochondrial K+ uptake of the myocyte, and an opener of mitoKCa protected hearts against infarction.