Sex reversal and growth performance in juvenile females of the freshwater crayfish <Emphasis Type="Italic">Cherax quadricarinatus</Emphasis> (Parastacidae): effect of increasing temperature and androgenic gland extract in the diet

Monosex male culture of C. quadricarinatus is proposed for increasing yields because males reach a larger size at harvest than females. An experiment was done to evaluate the effects of androgenic gland extract and temperature on sex reversal and somatic growth in early juvenile females. Females were exposed to the following experimental conditions: C: control food and temperature maintained at 26 ± 1°C; HT (high temperature): control food and temperature maintained at 28.5 ± 1°C; VHT (very high temperature): control food and temperature maintained at 31 ± 1°C; AG: food with enriched with androgenic gland (1/10 dose for each juvenile per day) and temperature maintained at (26 ± 1)°C. The juveniles were weighed, sexed, and growth increment (GI) and growth rate (GR) were calculated twice a month. The HT and AG groups differed from the C group in GI and GR indicating a greater somatic growth. At the end of the experiment, the HT and AG groups had similar weight but only the HT group had enhanced oocyte diameter, with some vitellogenic oocytes compared to the C group. In the HT group, there was significant sex reversal, as indicated by development of male and intersex male characteristics in different individuals. Both temperature and AG diet have a high potential for culture of this species because of their enhancement of somatic growth; higher temperature increases the proportion of males, a desirable characteristic of cultured populations.     

Regulation of growth, fatty acid composition and delta 6 desaturase expression by dietary lipids in gilthead seabream larvae (Sparus aurata)

The Δ6 and Δ5 desaturases and elongases show only very limited activity in marine fish, and little is known of the possibility of enhancing Δ6 desaturase gene expression in these fish. The use of plant oils in marine fish diets is limited by their lack of n−3 highly unsaturated fatty acids (HUFA) despite an abundant content of the 18C fatty acid precursor linoleic and α-linolenic acids. The objective of the present study was to determine the ability of larval gilthead seabream to utilize vegetable oils and assess the nutritional regulation of Δ6 desaturase gene expression. Seventeen-day-old gilthead seabream larvae were fed during a 17-day period with one of four different microdiets formulated with either sardine fish oil (FO), soybean, rapeseed or linseed oils, respectively, or a fifth diet containing defatted squid meal and linseed oil. Good larval survival and growth, both in terms of total length and body weight, were obtained by feeding the larvae either rapeseed, soybean or linseed oils. The presence of vegetable oils in the diet increased the levels of 20:2n−9 and 20:2n−6, 18:2n−9, 18:3n−6, 20:3n−6 and 20:4n−6, in larvae fed rapeseed and soybean oils in comparison to those fed FO. In addition, a sixfold increase in the relative expression of Δ6 desaturase-like gene was found in larvae fed rapeseed and soybean oils, denoting the nutritional regulation of desaturase activity through its gene expression in this fish species. However, feeding linseed oil did not increase the expression of the Δ6 desaturase gene to such a high extent.     

Serological and pathogenic characterization of Erysipelothrix rhusiopathiae isolates from tonsils of slaughter pigs in Indonesia

Erysipelothrix rhusiopathiae was isolated from tonsils of 245 (35.7%) of 687 apparently healthy slaughter pigs in Indonesia during the period of June 1987 to February 1988. A total of 150 of the 245 E. rhusiopathiae isolated could be serotyped within the 22 recognized serotypes. Serotype 2 was most prevalent with 23.7%, followed by Serotypes 11, 12, 1a, 5 and 6 representing 7.3, 5.3, 4.9, 4.9 and 4.1% of the isolates, respectively. The nine other serotypes (Serotypes 1b, 3, 4, 8, 9, 10, 13, 19 and 22) combined to make up 11.0% of the isolates. Antibiotic-resistant strains were not found. Of 86 selected isolates belonging to various serotypes, 76 (88.4%) were highly virulent for mice (LD50 less than 10(3.0) colony-forming units). In swine, 40 (51.2%) of 78 isolates induced local or generalized urticarial lesions after intradermal inoculation, and the remaining 38 isolates induced no clinical signs. Of 76 isolates used for challenge in the cross-protection study, 29 (38.2%) killed greater than 40% of mice immunized with an erysipelas bacterin marketed in Indonesia. A tendency to be refractory to the bacterin-induced immunity was observed in some isolates of various serotypes, but this characteristic was not consistent.     

Early luteal development in Santa Inês ewes superovulated with reduced doses of porcine follicle‐stimulating hormone

The aim was to compare the early luteal development in ewes superovulated with different doses of pFSH. Twenty‐nine Santa Inês ewes received a progesterone device (CIDR®) for 8 days. Gonadotrophic treatment started on Day 6: G200 (control, n = 9, 200 mg); G133 (n = 10, 133 mg); and G100 (n = 10, 100 mg of pFSH). On Day 6, all females received eCG (300 IU). B‐mode and spectral Doppler ultrasonography were performed daily during the early luteal phase (Days 11–15) to monitor the development of corpora lutea (CLs; dimensions) and ovarian arteries indices. CLs were also classified as normal or prematurely regressed (PRCL) on Day 15 by videolaparoscopy. Ewes from G100 and G133 showed gradual increase in luteal diameter during the early luteal phase (p < 0.001), whereas G200 animals presented increase from Day 11 to Day 13, and then decrease on Days 14 and 15 (p < 0.001). The G200 females showed greater percentage of PRCL (45.20%) than those of the other groups (p < 0.001). The normal CLs number was greater in G100 than in G133 (p = 0.04), while the PRCL number was greater in G200 than in the other groups (p = 0.03). Resistive index (RI) was greater in G200 than in G100 (p = 0.02). RI was lower in Day 12 than Day 15 (p = 0.02). Pulsatility index (PI) was greater on Days 14 and 15 (p < 0.01). In conclusion, the lowest dose of pFSH (100 mg) can be considered sufficient for an efficient superovulatory response in sheep, producing better CLs development dynamic in early luteal phase and ovarian blood perfusion and smaller number of PRCL than the traditional (200 mg) pFSH dose.     

Perturbations in the uterine luminal fluid composition are detrimental to pregnancy establishment in cattle

Background: A major,unresolved issue is how the uterine microenvironment determines pregnancy success in cattle.Before implantation,conceptus development depends on the uterine secretome(i.e.,histotroph).Despite its pivotal role,little is known about the dynamics of histotroph synthesis and changes in composition throughout the early diestrus and the relevance to pregnancy establishment.We hypothesize that disturbances on histotroph composition affect the establishment of pregnancy.Aim was to disturb histotroph composition at early diestrus and verify the effects on:(Exp.1) timing to restore its composition; and(Exp.2) pregnancy rate after multiple-embryo transfer.Estrous cycle of multiparous Nelore cows were synchronized and estrus was considered d 0(D0) of the experiments.Disturbance was through flushing each uterine horn with 30 m L of DMPBS and collecting the resulting uterine luminal flushing(ULF) on D1; D4; D7; D1 + D4 + D7.Control group remained not-collected.In Exp.1,ULF was collected on D7.5 from all animals and used for quantification of total protein concentration and abundance of albumin.In Exp.2,three in vitro-produced embryos were transferred to the uterine horn ipsilateral to the ovary containing the CL on D7.5 and pregnancy was checked on D25 by ultrasound.Results: In Exp.1,ULF collection on D4 or D7 increased(1.5-to 2.2-folds) the total protein concentration and albumin abundance.ULF collection on D1 did not alter(P 0.10) these endpoints.In Exp.2,ULF collected on D4 or D7 decreased pregnancy rates to approximately half of that measured in the remaining groups.Conclusions: Subtle perturbations imposed to the native intrauterine milieu,such as those caused by a single,low-volume collection of ULF,profoundly disturbs intrauterine composition and pregnancy success.At least 4 d were necessary for the uterus to recover its composition and the functional capacity to carry post-implantation gestation.     

IMAGING DIAGNOSIS —ANTEMORTEM DETECTION OF OLIGODENDROGLIOMA “CEREBROSPINAL FLUID DROP METASTASES” IN A DOG BY SERIAL MAGNETIC RESONANCE IMAGING

An English Bulldog underwent radiation therapy of an intracranial, left lateral ventricle mass. Following resolution of the primary mass, an intraventricular fourth ventricle lesion developed. Subsequently, multiple lesions developed from the cervical central canal and leptomeninges. Serial magnetic resonance imaging documented the propagation of lesions along the cerebrospinal fluid (CSF) pathways, known as “CSF drop metastasis.” Histopathology confirmed multifocal intraventricular and leptomeningeal oligodendroglioma. Oligodendroglioma should be included in the differential diagnosis for an intraventricular tumor exhibiting apparent CSF drop metastasis.     

Prevalence and anatomopathological characterization of cutaneous squamous cell carcinomas with regional and distant metastases in dogs and cats: 20 cases (1985–2020)

The aim of this study was to assess the prevalence of regional and distant metastases from cutaneous squamous cell carcinomas (SCCs) in dogs (n = 11) and cats (n = 9) in a retrospective case series over 36 years (1985–2020), as well as to characterize its macroscopic aspects (location and size), degree of differentiation (well, moderately and poorly differentiated [WD, MD and PD, respectively]) and the rate of cell proliferation, by counting the AgNORs. Immunohistochemistry (IHC) was used to identify patterns of tumour migration and invasion (islands, ribbons, cords, small aggregates, individual cells [fusiform and amoeboid]) and to evaluate the intensity of desmoplasia and the amount of myofibroblasts. The prevalence of metastatic SCCs was 4.39% (21/478), being 3.8% in dog (12/309) and 5.3% in cat (9/169). Metastases affected lymph nodes in all dogs and 66% (6/9) of cats, and less frequently distant organs. Primary tumours predominantly affected the abdominal skin in dogs and the nasal planum in cats. Among the 20 cases, 52% were MDs, 34% were WDs, and 14% were PDs. Histological lesions suggestive of exposure to chronic solar radiation were present in 57% (8/14). The main patterns of tumour migration and invasion were islands for WD SCCs and individual cells for PD SCCs. MD SCCs had a mix of patterns. In cats, individual spindle cells were restricted to PDs. A marked desmoplastic reaction was more associated with PD SCCs and often with MDs. This study highlights that the prevalence of SCC metastases in dogs and cats is predominantly regional. The IHC was essential in the identification of individual fusiform keratinocytes, whose presence in surgical margins may represent a greater risk of recurrence. Although the presence of myofibroblasts was observed in all infiltrative and metastatic tumours, further studies evaluating these cells may be important to better understand their role in the tumour microenvironment of cutaneous SCCs with metastasis in dogs and cats.     

High lysyl oxidase expression is an indicator of poor prognosis in dogs with cutaneous mast cell tumours

Mast cell tumour (MCT) is one of the most frequent skin tumours in dogs. Due to their unpredictable biological behaviour, MCTs often cause several therapeutic frustrations, leading to investigation regarding prognostic markers. Lysyl oxidase (LOX) is an enzyme that promotes extracellular matrix stability and contributes to cell migration, angiogenesis and epithelial-mesenchymal transition. Its expression positively correlates with poor prognoses in several human and canine mammary cancers. The aim of this study was to characterise the immunohistochemical expression of LOX in MCT samples and compare it with histological grading and post-surgical survival. Twenty-six tumours were submitted to immunohistochemistry for LOX expression evaluation. All samples were positive for LOX, with variable percentages of cytoplasmic and nuclear positivity. Cytoplasmic positivity was significantly higher in high-grade MCTs (P = .0297). Our results indicate that high expression of cytoplasmic LOX in neoplastic mast cells is an indicator of poor prognosis for canine cutaneous MCTs.     

Photoprotection of vitamins in skimmed milk by an aqueous soluble lycopene-gum Arabic microcapsule

Riboflavin (Rf)-mediated photosensitized degradation of vitamins A and D3 in skimmed milk under illumination with a white fluorescence lamp was studied by using the HPLC technique. The photosensitized degradation of both vitamins followed first-order kinetics, and the temperature effect on the observed photodegradation rate constant allowed the determination of the activation energy Ea as being 4 and 16 kcal/mol for vitamins A and D3, respectively. The addition of lycopene microencapsulated by spray-drying with a gum arabic-sucrose (8:2) mixture (MIC) produced a reduction of ca. 45% in the photosensitized degradation rate of both vitamins. Front-face fluorescence experiments showed the same photoprotection factor in the degradation of Rf itself, indicating that the photodegradation mechanism involved Rf-mediated reactive species, such as the excited triplet state of Rf, 3Rf*, and/or singlet molecular oxygen, 1O2. The interaction of both 3Rf* and 1O2 with MIC was evaluated in aqueous solutions by using laser-induced time-resolved absorption or emission spectroscopy, and the contribution of an inner-filter effect in the presence of MIC in skimmed milk was evaluated by diffuse reflectance spectroscopy. The main operating mechanism of photoprotection is due to the deactivation of 3Rf* by the proteic component of gum arabic; thus, gum arabic based microcapsules could be used to improve the photostability of milk during its storage and/or processing under light.