Semen quality during vincristine treatment in dogs with transmissible venereal tumor

The aim of this study was to evaluate the direct effects of vincristine on semen quality in dogs with transmissible venereal tumor (TVT). We examined the semen of 17 dogs suffering from TVT during vincristine treatment. Each animal received 0.6 mg, i.v. vincristine sulphate per square meter of body surface, per week for 4 wk until complete regression of the tumor. The following semen parameters were evaluated: semen volume (second fraction), sperm concentration, total spermatozoa per ejaculate, percentage of progressively motile spermatozoa, percentage of dead spermatozoa, percentage of swollen spermatozoa (hypo-osmotic swelling test) and percentage of morphologically abnormal spermatozoa (primary and secondary defects). Semen was collected and evaluated prior to the beginning of treatment, 3 d after each vincristine injection and 15 d after the last injection. Semen characteristics transiently deteriorated during treatment, but returned to normal 15 d later. These changes were attributed to a direct effect of vincristine on the extragonadal spermatozoal reserves contained in the epididymis and ductus deferens. A GnRH stimulation test was also performed after each semen collection in order to assess the function of the hypothalamic-pituitary-Leydig cell axis. No effect was noted on the above axis.     

How dogs influence the evaluation of psychotherapists

Abstract

Research has shown that the presence of a companion animal reduces anxiety, encourages interaction among humans and enhances the way in which people are perceived. These are all effects which would be useful in a psychotherapeutic setting. On this basis the current study investigated the effect of the presence of a dog on the way in which people perceive psychotherapists. The study utilized an experimental design in which participants viewed a videotape of one of two therapists who were either with or without a dog. It was hypothesized that people would respond more positively to the psychotherapists when accompanied by a dog; specifically, that they would be more generally satisfied and would be more willing to disclose personal information, and that these effects would be influenced by attitudes towards pets. The first two hypotheses were confirmed. The effect was most pronounced among those who were the least positive toward the psychotherapist, demonstrating a ceiling effect. Contrary to the last hypothesis, attitudes toward pets had no influence on the perceptions of psychotherapists. History of pet ownership had only minimal impact on the results. Practical applications and directions for further research are discussed.     

Semen quality and presence of cytokines in seminal fluid of bull ejaculates

It has been postulated that cytokines play an immunoregulatory role in human semen. The presence and levels of various cytokines, namely the interleukins 6, 10 (IL-6 and IL-10) and tumor necrosis factor alpha (TNFalpha) were investigated in the seminal plasma of six fertile crossbred bulls (Bos taurus x Bos indicus), using specific enzyme immunoassay. Cytokine levels were related to the semen quality of these bulls. A direct significant correlation between the level of IL-10 and individual sperm motility (r=0.84, P<0.036) was observed. The levels of IL-6 and IL-10 were inversely correlated (r=-0.93, P<0.006) and likewise in the same way an inverse correlation between the level of IL-6 and TNFalpha was observed (r=-0.84, P<0.037). These results confirm that cytokines are present in bull semen as has been demonstrated in human semen.     

A second KRT71 allele in curly coated dogs

Major characteristics of coat variation in dogs can be explained by variants in only a few genes. Until now, only one missense variant in the KRT71 gene, p.Arg151Trp, has been reported to cause curly hair in dogs. However, this variant does not explain the curly coat in all breeds as the mutant ¹⁵¹Trp allele, for example, is absent in Curly Coated Retrievers. We sequenced the genome of a Curly Coated Retriever at 22× coverage and searched for variants in the KRT71 gene. Only one protein‐changing variant was present in a homozygous state in the Curly Coated Retriever and absent or present in a heterozygous state in 221 control dogs from different dog breeds. This variant, NM_001197029.1:c.1266_1273delinsACA, was an indel variant in exon 7 that caused a frameshift and an altered and probably extended C‐terminus of the KRT71 protein NP_001183958.1:p.(Ser422ArgfsTer?). Using Sanger sequencing, we found that the variant was fixed in a cohort of 125 Curly Coated Retrievers and segregating in five of 14 additionally tested breeds with a curly or wavy coat. KRT71 variants cause curly hair in humans, mice, rats, cats and dogs. Specific KRT71 variants were further shown to cause alopecia. Based on this knowledge from other species and the predicted molecular consequence of the newly identified canine KRT71 variant, it is a compelling candidate causing a second curly hair allele in dogs. It might cause a slightly different coat phenotype than the previously published p.Arg151Trp variant and could potentially be associated with follicular dysplasia in dogs.     

Semen quality of postpubertal boars during increasing and decreasing natural photoperiods

The present study analyses the effects of increasing and decreasing photoperiods on the semen quality of 20 selected postpubertal Landrace boars. The boars were exposed, throughout 75 days, to increasing and decreasing photoperiods of natural light, a constant temperature of 21 +/- 1 degrees C and 60-70% of humidity, fed with a nutritious diet and, submitted to a rhythm of semen collection of twice a week. During the last 2 weeks of each treatment, semen samples were analysed and the parameters measured were: ejaculate volume and pH, sperm concentration, sperm production and the number of semen doses per ejaculate, sperm vitality, sperm motility, osmotic resistance of spermatozoa and sperm morphology. The comparative analysis between increasing and decreasing photoperiods indicated that the semen quality of boars exposed to a decreasing photoperiod was reduced as a consequence of decreases in sperm concentration, sperm production and the number of semen doses. There was no difference between increasing and decreasing photoperiods in terms of sperm vitality and sperm motility, nor in the osmotic resistance of spermatozoa to isotonic and hypotonic media. The analysis of sperm morphology showed significantly lower frequencies of mature and immature spermatozoa with a distal cytoplasmic droplet, and significantly higher frequencies of immature spermatozoa with a proximal droplet in boars exposed to the decreasing photoperiod. These results indicate that the sperm quality of the selected boars decreased during decreasing photoperiods, in comparison with increasing photoperiods, mainly due to impaired testicular function.     

Semen quality and sperm output of Yankasa rams at different ages

Three groups of three Yankasa rams aged 1.4, 2.4, and 3.4 yr, weighing 32.8 +/- 0.8, 47.9 +/- 1.4, and 48.8 +/- 1.3 kg, and with scrotal circumferences measuring 26.8 +/- 0.9, 28.9 +/- 0.3, and 30.3 +/- 1.3 cm (mean +/- SEM), respectively, were used for this study. The rams were ejaculated once per day for 14 d using an artificial vagina and their semen quality and sperm output determined. For the three groups, ejaculate volume, sperm concentration, sperm motility, percentage of morphologically normal sperm, and total sperm output per ejaculate averaged 0.72 +/- 0.03, 0.90 +/- 0.04, and 0.88 +/- 0.03 ml; 3.421 +/- 0.133, 4.025 +/- 0.179, and 4.673 +/- 0.184 x 10(9)/ml; 83.2 +/- 2.3, 84.6 +/- 1.5, and 74.0 +/- 2.4%; 96.2 +/- 0.3, 96.0 +/- 0.4, and 95.4 +/- 0.4%; and 2.469 +/- 0.141, 3.663 +/- 0.237, and 4.163 +/- 0.247 x 10(9) sperm, respectively. Differences between groups were significant for all semen traits except for percentage of morphologically normal sperm. Total sperm output per ejaculate (Y; x 10(9)) was significantly correlated with scrotal circumference (X; cm) by the geometric regression equation Y = 0.000128 X(3.03) (r = 0.71; P < 0.05). Ejaculate characteristics were not influenced by day of collection except for percentage of morphologically normal sperm, which was significantly (P < 0.01) lower on the first day of collection.     

Enhancement of the sensitivity of Tetrahymena to a second hormonal influence by hormone pretreatment

Diiodotyrosine and serotonin enhance the growth of Tetrahymena. A second exposure of the unicellular to these hormones accounts for a still greater increase of its growth rate, probably due to the amplification of the receptor induced by the first exposure.     

Semen quality parameters and embryo lethality in mice deficient for Trp53 protein

Trp53 is a protein which is able to control semen parameters in mice, but the extent of that control depends on the genetic background of the mouse strain. Males from C57BL/6Kw, 129/Sv, C57BL×129 -p53+/+ (wild type controls) and C57BL×129-p53-/- (mutants) strains were used in the study, and histology and light microscopy were applied to evaluate the influence of genetic background and Trp53 (p53) genotype on testes morphology and semen quality in male mice. We showed that sperm head morphology, maturity and tail membrane integrity were controlled only by the genetic background of C57BL/6Kw and 129/Sv males, while testes weight and sperm concentration depended on both the genetic background and p53 genotype. Cell accumulation in seminiferous tubules may be responsible for heavier testes of p53-deficient males. In addition, to examine the effect of sex and p53 genotype on embryo lethality, pairs of control (C57BL×129-p53+/+) and heterozygous (C57BL×129-p53+/-) mice were examined. Before day 7 post coitum (dpc), female and male embryos were equally resorbed in both crosses types. After 7 dpc, preferential female embryo lethality in the heterozygote pairs was responsible for the skewed sex ratio in their progeny. Also, mutant female and male newborns were underrepresented in the litters of the heterozygous breeding pairs.     

Patch quality and connectivity influence spatial dynamics in a dune wolfspider

The spatial population dynamics of the wolfspider Pardosa monticola, inhabiting patchily distributed grasslands in the Flemish coastal dunes of Belgium and Northern France were investigated with incidence function models using field survey data from 1998 and 2000. Vegetation height and patch size were related to habitat quality. Mark-recapture experiments revealed maximum cursorial dispersal distances of 280 m for moss dunes and 185 m for higher dune grassland. Higher shrub vegetation appeared to be dispersal barriers. These habitat-dependant cursorial distances and the theoretically estimated ballooning distance were included with patch distances into a connectivity index for both dispersal modes. Forward multiple regression indicated that patch occurrence was influenced by habitat quality and ballooning connectivity. Habitat quality and cursorial connectivity explained patterns in short-term colonisation. Extinction appeared to be stochastic and not related to habitat quality and connectivity. Genetic differentiation and variability was low. The discrepancy between the estimated low dispersal capacity and the indirect estimate of gene flow ( F(ST)) indicates that historical population dynamics and/or historical ballooning dispersal influence the genetic structure in this species.     

Semen quality in a Giant Panda (Ailuropoda melanoleuca) in relation to estrus of a nearby resident female panda

Semen quality was determined in a sexually mature male Giant Panda, electroejaculated 13 times during a 5-year interval, before, during and after estrus of a female Giant Panda housed nearby. Testis volume and plasma testosterone concentrations were also measured. Mean testis volumes were 1223.0 +/- 64.7(S.E.M.)cm3 (before estrus), 1213.2 +/- 218.2 cm3 (during estrus), and 1360.2+/-160.4 cm3 (after estrus). Compared to before and during estrus in the female, testis volume decreased 70 days after estrus and there was no projectile ejaculation. The mean semen volume and sperm count were 2.2+/-0.7 mL and 8.3 +/- 3.1 x 10(8) before estrus, 2.4 +/- 0.9 mL and 5.7 +/- 0.9 x 10(8) during estrus, and 1.3 +/- 0.3 mL and 8.1 +/- 1.7 x 10(8) after estrus, respectively. The semen volume, sperm count, and testis volume markedly differed from 90 days before estrus until 66 days after estrus, whereas no marked differences in sperm motility, sperm viability, and proportion of morphologically abnormal spermatozoa were observed. Plasma testosterone concentrations were elevated both before and during estrus (0.62 +/- 0.23 ng/mL and 0.95 ng/mL), but decreased substantially after estrus (0.20 +/- 0.0 ng/mL). We inferred that spermatogenesis was active in this male panda from approximately 3 months before estrus to 2 months after estrus in the adjacent female.     

Physiology and pharmacology of ejaculation

Ejaculation requires an interplay of peripheral actors comprising, among others, smooth and skeletal fibers, glandular and endothelial cells. These actors are driven by vegetative and somatic innervations, deriving essentially from the spinal cord, in turn controlled by cerebral structures and endocrine factors, mostly steroids; These controls require sensitive afferences and command two steps, emission under autonomic control, and ejaculation per se which further involves somatic motoneurons. This review first describes the peripheral innervation of the part of the genital tract concerned in ejaculation, in which the sympathetic component is predominant and releases noradrenalin and neuropeptides; however parasympathetic and somatic components also play a role. At the spinal level, control circuits are organized into networks influenced by spinal structures, which have been discovered through selective lesions or stimulations, as well as by retrograde trans-synaptic tracing with neurotropic viruses. Among these structures, the median preoptic area and the hypothalamic paraventricular nucleus are major regulation sites. On the other hand, serotoninergic and also dopaminergic and adrenergic systems are implicated as well in the command of ejaculation; the latter constitute priviledged targets for a pharmacological treatment of dysfunctions.     

Semen quantity and quality correlate with bank vole males’ social status

Laboratory studies reveal that in several rodent species the females prefer dominant males as mating partners. Here we investigate the correlation between bank vole males’ social rank and their sperm quality and quantity. We used agonistic encounters to determine males’ social status. Sperm quality was assessed by its motility, viability, maturity, morphology and sperm tail membrane integrity. Relatively more dominant males were heavier than males of lower social status. The males’ social position affected the testes, seminal vesicles and coagulation gland development. The weights of these reproductive organs were significantly higher in more dominant males than in more subordinate males. Sperm counts and the values of the other parameters describing sperm quality were higher in high-ranking males than in subordinates. Our results suggest that bank vole females benefit from choosing and mating with high-ranking males by obtaining more and better-quality sperm.     

Green fluorescent protein ground states: the influence of a second protonation site near the chromophore

The photophysical properties of most green fluorescent protein mutants (GFPs) are strongly affected by pH. This effect must be carefully taken into account when using GFPs as fluorescent probes or indicators. Usually, the pH-dependence of GFPs is rationalized on the basis of the ionization equilibrium of the chromophore phenol group. Yet many different mutants show spectral behavior that cannot be explained by ionization of this group alone. In this study, we propose a general model of protonation comprising two ionization sites (2S model). Steady-state optical measurements at different pH and temperature and pH-jump relaxation experiments were combined to highlight the thermodynamic and kinetic properties of paradigmatically different GFP variants. Our experiments support the 2S model. For the case of mutants in which E222 is the second protonation site, thermodynamic coupling between this residue's and the chromophore's ionization reactions was demonstrated. In agreement with the 2S model predictions, X-ray analysis of one of these mutants showed the presence of two chromophore populations at high pH.     

Semen quality of stallions challenged with the Kentucky 84 strain of equine arteritis virus

Equine arteritis virus (EAV) is the causal agent of equine viral arteritis (EVA), a respiratory and reproductive disease of equids. Some strains of EAV can cause fever, leukopenia, and dependent edema of the limbs, scrotum, and preputium in the acutely infected stallion. We hypothesized that fever and scrotal edema observed during the acute phase of the infection, but not the presence of EAV, have an adverse effect on semen quality. A group of seven stallions were intranasally inoculated with the Kentucky 84 (KY84) strain of EAV. Stallions were monitored for clinical signs of EVA until 42 days postinoculation (dpi). Semen was collected every other day for the first 15 days and 2 times a week up to 79 dpi. Additional samples were collected at 147, 149, and 151 dpi. Semen from each stallion was evaluated on the basis of motion characteristics, total number of spermatozoa, membrane integrity, and morphology. Virus infectivity titers were determined in RK-13 cells. Significant decreases in sperm quality were observed between 9 and 76 dpi. LOWESS (locally weighted scatterplot smoothing) curves for each horse were fit and integrated to quantify spermatozoa exposure to fever, virus, and edema over a period of 67 days before each ejaculation. Linear mixed models were then fit to isolate the effects of each factor on semen quality. Scrotal edema and fever were found to exert independent effects on all the semen quality parameters (P ≤ 0.002), whereas virus seems to exert little to no direct effect, as virus titers remained high long after semen quality returned to baseline.     

千金子制霜前后提取物对4类肠道菌影响的体外研究

目的 研究并对比千金子制霜前后提取物对正常SD大鼠肠道菌群的影响。方法 采用酶标比浊法,体外不同浓度千金子制霜前后提取物作用下的细菌生长曲线来研究制霜对长双歧杆菌、嗜酸乳杆菌、大肠埃希菌和粪肠球菌4种代表性肠道菌的作用,分析其对4种肠道菌生长的影响。结果 千金子生品提取物和霜品提取物对4种肠道菌均有抑制作用,且随着给药浓度的增大,抑制作用增强。相同生药量下,千金子生品提取物对4种肠道菌的抑制作用均大于霜品提取物,且低剂量下会使条件致病菌粪肠球菌和大肠埃希菌的数量减少。推测千金子制霜前后均会一定程度影响肠道菌群的稳态,制霜后对4种肠道菌的影响弱于生品,与千金子制霜后泻下作用缓和的研究结果相吻合。结论 从肠道微生态角度为切入点,考察千金子制霜前后提取物对肠道菌群数量和生长情况的干预作用,可初步揭示千金子制霜与肠道菌群数量和结构变化可能存在的相关性,为深入揭示千金子制霜减毒微生物学机制奠定基础。     

The influence of the duodenal passage on postprandial neurotensin release in dogs

All types of gastric resections induce an abnormal release of gastrointestinal hormones. The missing duodenal passage seems to be the most important factor for these disturbances. In the present study we have examined the effect of exclusion and restoration of the duodenal passage on the postprandial release of neurotensin in dogs. After feeding a standard canned dog meal, exclusion of the duodenal passage by a Billroth-II-resection caused a significant increase in postprandial neurotensin release compared to the control group (peak levels 52 +/- 5.6 to 29 +/- 6 pg/ml preoperatively, integrated output 2132 +/- 228 to 3604 +/- 213 pg/ml x 150 min. p less than 0.05). Reconstruction of the duodenal passage by the Biebl-Henly-Soupault-procedure tended the elevated neurotensin levels towards normal (peak levels 36 +/- 4.8 pg/ml, integrated output 2448 +/- 236 pg/ml x 150 min., p less than 0.05). From our data we conclude that changes in intestinal transit time are responsible for the pathological increase in neurotensin release after exclusion of the duodenal passage.