Computer tomographic imaging in 4 dogs with primary nasal canine transmissible venereal tumor and differing cellular phenotype

Primary nasal canine transmissible venereal tumor (CTVT) without genital affection is uncommon. The aim of this report was to describe the primary nasal CTVT findings and CT staging in 4 dogs with different cytological phenotypes. Three male dogs and 1 bitch were evaluated for their chronic histories of sneezing, snoring, mucopurulent nasal discharge and nasal deformation. Cytological examination of nasal secretions suggested CTVT, confirmed by histopathological examination and LINE‐1/c‐myc. Males had the plasmacytoid phenotype of CTVT, and the bitch had the lymphocytoid phenotype. CTVT were staged based on the CT findings using modified Adams staging system. The bitch was classified as stage 1, 2 males were classified as stage 3 and 1 male as stage 4. All dogs had a complete tumoral remission after chemotherapy. Plasmacytoid phenotype was identified in cases with most important damage of the nasal cavity. However, the cytological type did not affect the response to chemotherapy.     

Gut microbes limit growth in house sparrow nestlings (Passer domesticus) but not through limitations in digestive capacity

Recent research often lauds the services and beneficial effects of host‐associated microbes on animals. However, hosting these microbes may come at a cost. For example, germ‐free and antibiotic‐treated birds generally grow faster than their conventional counterparts. In the wild, juvenile body size is correlated with survival, so hosting a microbiota may incur a fitness cost. Avian altricial nestlings represent an interesting study system in which to investigate these interactions, given that they exhibit the fastest growth rates among vertebrates, and growth is limited by their digestive capacity. We investigated whether reduction and restructuring of the microbiota by antibiotic treatment would: (i) increase growth and food conversion efficiency in nestling house sparrows (Passer domesticus); (ii) alter aspects of gut anatomy or function (particularly activities of digestive carbohydrases and their regulation in response to dietary change); and (iii) whether there were correlations between relative abundances of microbial taxa, digestive function and nestling growth. Antibiotic treatment significantly increased growth and food conversion efficiency in nestlings. Antibiotics did not alter aspects of gut anatomy that we considered but depressed intestinal maltase activity. There were no significant correlations between abundances of microbial taxa and aspects of host physiology. Overall, we conclude that microbial‐induced growth limitation in developing birds is not driven by interactions with digestive capacity. Rather, decreased energetic and material costs of immune function or beneficial effects from microbes enriched under antibiotic treatment may underlie these effects. Understanding the costs and tradeoffs of hosting gut microbial communities represents an avenue of future research.     

Embryonic development in corkwing wrasse,Symphodus melops

Corkwing wrasse, Symphodus melops, is one of the main species used as cleaner fish to combat sea lice infestation in salmon aquaculture; however, there is little knowledge about its biology. Here, we describe the embryonic development of this species and examine the viability of the eggs under three temperature regimes. The experiments were conducted at three water temperature regimes, 12, 15, and 18°C, which resemble common sea water temperatures registered during the spawning season of corkwing wrasse at different latitudes along the Norwegian coast. Corkwing wrasse spawn small spherical eggs of 0.75–0.80 mm in diameter (mean 0.78, CV = 3.6%) with several oil droplets and go through eight developmental stages until hatching. The shortest hatching time was registered after 144 hr at 18°C and after 222 and 372 hr at 15 and 12°C, respectively. These observations provide important baseline biological information to advance the establishment of commercial rearing techniques and sustainable fishing management practices for this heavily exploited species.     

Correction to: The development of the Norwegian wrasse fishery and the use of wrasses as cleaner fish in the salmon aquaculture industry

Fisheries Science - A correction to this paper has been published: https://doi.org/10.1007/s12562-021-01502-z     

Transgenic poplar characterized by ectopic expression of a pine cytosolic glutamine synthetase gene exhibits enhanced tolerance to water stress

Physiological responses to water stress in hybrid poplar (INRA 7171-B4, Populus tremula L. x P. alba L.) lines transformed to overexpress a pine cytosolic glutamine synthetase (GS1) gene were compared with those of non-transgenic plants. Before, during and after a drought treatment, net photosynthetic rates (Anet) were higher in transgenic than in non-transgenic plants. Stomatal conductance (gs) was higher in transgenic than in non-transgenic plants before, but not after exposure to drought. Before drought treatment, a sudden reduction in photosynthetic photon flux caused a greater burst of CO2 efflux in transgenic than non-transgenic plants, indicating greater photorespiratory activity. Drought caused greater reductions in photochemical quenching, photosystem II (PSII) antennae transfer efficiency (Fv'/Fm') and light-adapted PSII yield (PhiPSII) in non-transgenic than in transgenic plants, especially at low irradiances. Antennae-based thermal dissipation was higher in transgenic plants than in non-transgenic plants both during the imposition of drought and 1 or 3 days after the relief of drought. Under severe water stress and subsequently, transgenic plants maintained a higher expression of glutamine synthetase, glutamate synthase and Rubisco and higher concentrations of chlorophyll and glycine than non-transgenic plants. These findings indicate that overexpression of pine cytosolic GS1 enhanced sustained photosynthetic electron transport capacity during severe stomatal limitation. The data also suggest that ectopic expression of cytosolic GS increases photorespiratory activity, and that this serves as a protective sink for electrons from photosynthetic reaction centers.     

Soil Carbon and Nitrogen Dynamics Followed by a Forest-to-pasture Conversion in Western Mexico

Gains and losses of soil carbon (C), have been reported when tropical forests are converted to pastures. Regional studies are crucial for setting regional baselines and explaining each particular trend, in order to solve this controversy. Tropical deciduous forest (TDF) is under high deforestation pressure, mainly for conversion to pastures. The present study compared soil organic C (SOC) and nitrogen (SON) in the surface layer (0–5 cm) of forest and pasture soils in a TDF of western Mexico. SOC and SON concentrations were 18 and 60% lower in pasture soils than in forest soils, and C:N ratio increased in pasture soils. Furthermore, pasture soils had lower labile C and available inorganic nitrogen (N) than forest soils. These results can be explained as a reduction in C inputs to pasture soils and management-induced disruption of soil aggregates. In forest soils, macroaggregates (> 250 μm) were predominant (85%), whereas in pasture soils they were reduced to 35% of dry sand-free soil mass. The estimated SOC and SON losses from the top 5 cm of soil were 3 Mg C ha⁻¹ and 0.9 Mg N ha⁻¹, respectively.     

Evaluation of the Watermark sensor for use with drip irrigated vegetable crops

The Watermark 200SS sensor was evaluated for the measurement of soil matric potential (SMP) with drip-irrigated vegetable crops. Pepper and melon crops were grown sequentially during autumn-winter and spring-summer, in a sandy loam soil in a greenhouse. Ranges of SMP were generated by applying three different irrigation treatments — 100, 50 and 0% of crop water requirements, during two treatment periods (16 December 2002–7 January 2003; 20 January–10 February 2003) in pepper and one treatment period (26 May–6 June 2003) in melon. Watermark sensors and tensiometers were positioned, at identical distances from irrigation emitters, at 10 cm soil depth, with four replicate sensors for each measurement. Electrical resistance from Watermark sensors and SMP from tensiometers were recorded at 30-min intervals. An in-situ calibration equation was derived using data from the first pepper treatment period. For data in the three treatment periods, SMP was calculated from Watermark electrical resistance using the in-situ, Thomson and Armstrong (in Appl Eng Agric 3:186–189 1987), Shock et al. (1998) and Allen (2000) calibration equations. Additionally, the Thomson and Armstrong (in Appl Eng Agric 3:186–189 1987) and Shock et al. (1998) equations were re-parameterised with the SOLVER^® function of Microsoft Excel 2000^® using data from the first pepper treatment period. Watermark-derived SMP, for each equation, were compared with tensiometer-measured SMP, for <-10, ?10 to ?30, ?30 to ?50 and ?50 to ?80 kPa ranges, using visual analysis, and relative root mean square error (RRMSE) and mean difference (Md) values. In rapidly drying soil, the Watermark-derived SMP responded considerably more slowly to continual drying and to drying between irrigations, regardless of the calibration equation used. Otherwise, the Watermark sensor was able to provide an accurate indication of SMP, depending on the calibration equation. The in-situ and re-parameterised equations were accurate for the conditions in which they were derived/re-parameterised. However, as the growing conditions increasingly differed from those original conditions, these equations lost their advantage compared to the two published equations, suggesting that they are not robust approaches. The Thomson and Armstrong (in Appl Eng Agric 3:186–189 1987) equation generally provided an accurate indication of SMP at >?30 kPa, measuring to ?2.5 kPa. Where the soil was not drying rapidly, the Shock et al. (1998) equation generally provided an accurate indication of SMP at ?30 to ?80 kPa. The use of dynamic data (collected every 30 min) compared to static data (collected only at 6 a.m.) did not influence the evaluation of calibration equations. This study suggested that the Watermark sensor can provide an accurate indication of SMP provided that a suitable calibration equation is derived/verified for the specific cropping conditions, and that the performance characteristics of the sensor are considered.     

Bulk milk urea concentrations and their relationship with cow fertility in grazing dairy herds in southern Chile

Milk urea determination is being used as a broad indicator of protein/energy imbalance in dairy herds. The main purpose of this study was to compare blood and bulk milk urea values in grazing herds, to evaluate their seasonal variation under South Chilean conditions, and to examine their potential relationships with herd fertility. The association between herd blood urea concentration (mean of seven lactating cows) and bulk milk urea concentration (tank containing milk from the previous 24 h) was determined in 21 diary herds. Reference values, seasonal and herd variance, and the frequency of herds with values outside a range of 2.5 to 7.3 mmol/l were determined in bulk milk samples obtained monthly for a period of one year from 82 suppliers at two creameries located in southern Chile. Finally, bulk milk urea was measured every two weeks in samples from 24 herds, and the first service conception rate (FSCR) from 2153 dairy cows was determined. Mean bulk urea concentration was highly correlated with mean herd blood urea concentration (r = 0.95; p < 0.01). Mean urea concentration in the bulk milk samples obtained during one year from 82 herds was 4.9 +/- 1.2 mmol/l, with a range of 1.5 to 11.6 mmol/l. The highest values were found during spring and the lowest values during the summer. There was a high seasonal variation (CV = 13-47%) and between-herd variation (CV = 20-31%). Out of a total of 984 samples, 5.4% had urea values > 7.3 mmol/l and 3.8% had values < 2.5 mmol/l. Of the 82 herds, 27% had values outside the reference interval (2.5-7.3 mmol/l) on two or more occasions. FSCR was lower in herds when the bulk milk urea was > 7.3 mmol/l (50.7%) than in cows, where the urea concentration was < 5.0 mmol/l (73.8%) at the time of insemination. The study concluded that bulk milk urea concentrations provided information similar to herd blood urea concentrations in local grazing dairy herds. There was a high frequency of herds with abnormal values, with large variations between herds and between seasons. Increased milk urea concentrations during spring were associated with lower conception rates.     

Changes in Eucalyptus globulus Labill. saplings growth and physiological parameters following fire-induced stem and crown damage in a plantation in north-western Spain

Stems and crowns of young Eucalyptus globulus Labill. saplings were experimentally damaged by fire to assess the short-term effects on tree growth and selected physiological parameters (stem sap flow density, electrical resistance of stem cambium and leaf stomatal conductance). Four different treatments were considered: partial stem damage (42 % of the stem circumference girdled by the direct application of heat in the cambium zone), crown foliage damage (56 % of crown volume scorched by heating the foliage with a torch), combined stem and crown damage, and no damage (control). Saplings displayed high sensitivity to crown scorching, in terms of basal area growth. The relative growth of the basal area of crown-damaged and stem + crown-damaged trees was, respectively, 3.1 and 6.2 times lower than that of undamaged trees for the 4 months following treatment. In contrast, stem injury alone did not have any negative effect on stem growth. The results suggest that tree growth is scarcely affected by low intensity surface fire and prescribed burning that do not affect the crown. Sap flow density, cambial electrical resistance and leaf stomatal conductance were useful indicators of the loss of physiological activity caused by fire. Although in the case of partial crown damage these parameters reflected a slight compensatory effect, the response was not sufficient to balance the loss of photosynthetic area. The study only focused on the initial effects of fire-related damage, and further research is clearly needed to determine the long-term effects of such damage.     

Cortisol secretion after adrenocorticotrophin (ACTH) and Dexamethasone tests in healthy female and male dogs

Background

For the conclusive diagnosis of Cushing''s Syndrome, a stimulating ACTH test or a low suppressive Dexamethasone test is used. Reports in other species than the dog indicate that plasma cortisol concentration after ACTH administration is affected by gender. We investigated the effect of gender on the cortisol response to ACTH and Dexamethasone tests in dogs.

Methods

Seven healthy adult Cocker Spaniels (4 females and 3 males) were assigned to a two by two factorial design: 4 dogs (2 females and 2 males) received IV Dexamethasone 0.01 mg/kg, while the other 3 dogs received an IV saline solution (control group). Two weeks later the treatments were reversed. After one month, ACTH was given IV (250 μg/animal) to 4 dogs (2 female and 2 males) while the rest was treated with saline solution (control group). Cortisol concentrations were determined by a direct solid-phase radioimmunoassay and cholesterol and triglycerides by commercial kits.

Results and Discussion

No effect of treatment was observed in metabolite concentrations, but females presented higher cholesterol concentrations. ACTH-treated dogs showed an increase in cortisol levels in the first hour after sampling until 3 hours post injection. Cortisol concentrations in Dexamethasone-treated dogs decreased one hour post injection and remained low for 3 hours, thereafter cortisol concentrations increased. The increase in cortisol levels from one to two hours post ACTH injection was significantly higher in females than males. In Dexamethasone-treated males cortisol levels decreased one hour post injection up to 3 hours; in females the decrease was more pronounced and prolonged, up to 5 hours post injection.

Conclusion

We have demonstrated that cortisol response to ACTH and Dexamethasone treatment in dogs differs according to sex.