Getting cosy in freshwater: Assumed to be brackish pike are not so brackish after all

Pike (Esox lucius) occupy coastal streams and rivers of the Baltic Sea, where they attain large sizes (>5 kg). These large sizes are perhaps due to the fact that they can tolerate relatively high salinities and can thus forage in the nearby more productive brackish environments. In an attempt to quantify the extent to which pike utilise brackish environments, and to provide some insight into the underlying causes for brackish water migrations, we tagged 30 pike from a western Baltic river with acoustic transmitters and were able to track 21 individuals for 1 year. Based on experienced from local anglers, this population was assumed to be brackish in nature, where individuals underwent freshwater migrations to spawn. Our findings however suggest that the smallest and most active individuals make short exits into brackish waters and do so on rare occasions. Our results further indicate that neither sex nor size is related to activity level. We suggest that these patterns reflect two distinct behaviours—active and passive—and that large pike can be supported by the food availability in the river, without the need to venture into coastal zones, thus defying the conventional view that Baltic pike are all brackish in nature.     

Diapause in Scelio chortoicetes Frogg

Ohne Zusammenfassung     

The activities of amylase and a trypsin‐like protease in the gut contents of germ‐free and conventional chickens

1. Proteolytic and amylase activities were assayed in the gut contents of germ‐free and conventional chickens aged 3 and 14 d.

2. The tendency was for the proteolytic activity to be increased and the amylase activity to be decreased in conventional chicks. These differences were statistically significant in the caecum.

3. All of the additional proteolytic activity detectable in the caecum of conventional chicks was inhibited by soyabean trypsin inhibitor. However, the increased activity was not detectable in the small intestine and was, therefore, not due to pancreatic trypsin.

4. Attempts to demonstrate in vitro bacterial production of a trypsin‐like enzyme were unsuccessful.     

High-throughput screening reveals small molecule modulators inhibitory to Acidovorax citrulli

Acidovorax citrulli is a seed-transmitted gram-negative bacterium that can cause substantial economic yield loss in watermelon and melon production worldwide. Four small-molecule libraries containing 4,952 compounds were selected for high-throughput screening against A. citrulli wild-type strain Xu3-14 by evaluation of growth inhibition. One hundred and twenty-seven molecules (2.5% hit rate) were identified as bactericidal or bacteriostatic against A. citrulli at 100 μM. Secondary screens indicated that 27 candidate compounds were more effective against A. citrulli Group II strains than Group I strains (classified using repetitive element PCR). Several compounds were inhibitory to other pathogenic bacteria, including Clavibacter michiganensis subsp. michiganensis and Xanthomonas campestris pv. campestris, but did not affect the growth of plant beneficial bacteria Pseudomonas fluorescens and Bacillus subtilis. More than half of the compounds did not inhibit germination of Arabidopsis or watermelon seeds. The effect of small molecules on A. citrulli seed-to-seedling transmission was evaluated by applying each compound to inoculated watermelon seeds and assessing seedling infection. Nine compounds were chosen for further investigation based on their reduction of percentage seedling infection and compiling scores on their specificity, sensitivity, and phytotoxicity obtained in the secondary screens. The five best compounds were selected (thiamphenicol, nadifloxacin, pipemidic acid, ciclopirox, and zinc pyrithione) for greenhouse tests and were found to effectively reduce the seed-to-seedling transmission of A. citrulli in both artificially and naturally infested seeds. These top five compounds provide a basis for future development of an A. citrulli-specific bactericide.     

Prevalence, clinical features, and causes of epistaxis in dogs: 176 cases (1996-2001)

OBJECTIVE: To determine prevalence, clinical features, and causes of epistaxis in dogs. DESIGN: Retrospective case series. ANIMALS: 176 dogs with epistaxis. PROCEDURES: Medical records were reviewed for information related to signalment, clinical features, diagnosis, and outcome. RESULTS: 132 (75%) dogs were initially examined by the hospital's emergency service; prevalence of epistaxis was 0.3%. Dogs with epistaxis were more likely to be old (> or = 6 years), male, and large (> or = 26 kg [58.5 lb]) than were dogs in a reference population. In 109 (62%) dogs with epistaxis, an underlying cause was identified; 115 underlying disorders were identified, with 90 classified as local and 25 classified as systemic. Local causes of epistaxis included nasal neoplasia (n = 35), trauma (33), idiopathic rhinitis (20), and periapical abscess (2). Systemic causes included thrombocytopenia (12), thrombocytopathia (7), coagulopathy (3), hypertension (2), and vasculitis (1). Dogs with local causes were more likely to have unilateral than bilateral epistaxis, but 11 of 21 (52%) dogs with systemic disorders also had unilateral epistaxis. Dogs with systemic disorders were more likely to have clinical signs of systemic disease. Duration of epistaxis (acute vs chronic), severity, and duration of hospitalization were similar for dogs with local versus systemic disorders. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that epistaxis was a common disorder in dogs and frequently regarded as an emergency. Local causes of epistaxis were predominant, but clinical features traditionally thought to be helpful in distinguishing local versus systemic causes could not be reliably used for this purpose.     

Histology and histochemistry of the major salivary glands in the southern white-breasted hedgehog (Erinaceus concolor)

This study aimed to investigate the major salivary glands in the southern white-breasted hedgehog (Erinaceus concolor) histologically and histochemically. Five adult males were included in this study. The results showed that anatomically the shape of the parotid, submandibular and sublingual glands of the Erinaceus concolor was respectively almost pear, elliptical to pyramidal and oval. Histologically, the parotid gland had serous acini and secretory cells showed negative reaction to alcian blue (AB) (pH = 2.5) and negative response to aldehyde fuchsin (AF), methylene blue (MB) and PAS stains. The submandibular gland was a mixed gland of mucous and serous acini. The mucous acini were strongly positive for PAS, AB, MB and AF. However, serous acini were week for PAS and negative against AB, MB and AF stains. The sublingual gland was purely composed of mucous acini. The mucous acini of the sublingual gland were strongly positives for PAS, AB and MB methods. While their reaction to the AF staining was negative. In conclusion, the histological and histochemical observations of the major salivary glands of the southern white-breasted hedgehog (E. concolor) indicated that these glands shown similarities and some special different histochemical features as compared to other mammalian species.     

Multicenter case-control study of risk factors associated with development of vaccine-associated sarcomas in cats

OBJECTIVE: To determine whether particular vaccine brands, other injectable medications, customary vaccination practices, or various host factors were associated with the formation of vaccine-associated sarcomas in cats. DESIGN: Prospective multicenter case-control study. ANIMALS: Cats in the United States and Canada with soft tissue sarcomas or basal cell tumors. PROCEDURE: Veterinarians submitting biopsy specimens from cats with a confirmed diagnosis of soft tissue sarcoma or basal cell tumor were contacted for patient medical history. Time window statistical analyses were used in conjunction with various assumptions about case definitions. RESULTS: No single vaccine brand or manufacturer within antigen class was found to be associated with sarcoma formation. Factors related to vaccine administration were also not associated with sarcoma development, with the possible exception of vaccine temperature prior to injection. Two injectable medications (long-acting penicillin and methyl prednisolone acetate) were administered to case cats more frequently than to control cats. CONCLUSIONS AND CLINICAL RELEVANCE: Findings do not support the hypotheses that specific brands or types of vaccine within antigen class, vaccine practices such as reuse of syringes, concomitant viral infection, history of trauma, or residence either increase or decrease the risk of vaccine-associated sarcoma formation in cats. There was evidence to suggest that certain long-acting injectable medications may also be associated with sarcoma formation.     

In utero programming of sexually differentiated gonadotrophin releasing hormone (GnRH) secretion

It has long been recognised that steroids can have both organisational and activational effects on the reproductive neuroendocrine axis of many species, including the sheep. Specifically, if the ovine foetus is exposed to testosterone during a relatively short 'window' of in utero development (from approximately day 30-90 of a 147 day pregnancy) the neural mechanisms regulating gonadotrophin releasing hormone (GnRH) secretion become organised in a male-specific manner. In post-natal life the consequences of foetal androgen exposure are sexually differentiated responses of the GnRH neuronal network to activation by factors such as photoperiod and ovarian steroid hormones. Studies in the gonadectomized lamb have demonstrated that elevated concentrations of oestrogen (E) are unable to trigger a preovulatory-like GnRH surge in the male and the androgenized ewe lamb. Further, these animals have markedly reduced sensitivity to the inhibitory actions of progesterone on tonic GnRH release compared with normal ewes. The reasons for these abnormal steroid feedback mechanisms may reside in sexually dimorphic inputs to the GnRH neurone, including those from oestrogen-receptive neurones in the arcuate nucleus that synthetize the neuropeptide, neurokinin B (NKB). The consequences of in utero androgen exposure are reflected in a progressive and dramatic impairment of fertility in the ovary-intact ewe.