Serologic and Urinary PCR Survey of Leptospirosis in Healthy Cats and in Cats with Kidney Disease

Background

Although there is serologic evidence of exposure of cats to Leptospira spp., clinical disease is rarely reported in cats.

Objective

To compare the seropositivity and urinary polymerase chain reaction (PCR) status for Leptospira spp. between healthy (H) cats and cats with kidney disease (KD), to investigate the serovars potentially involved, and to evaluate potential risk factors.

Animals

Two hundred and forty client‐owned cats.

Methods

Cats were prospectively recruited and classified based on physical examination, complete blood count, serum biochemistry profile, and urinalysis (125 H and 115 KD cats). Leptospira spp. serology (titers ≥1 : 100 considered positive) and urinary PCR were performed in all cats. Data assessing risk factors, obtained from a questionnaire, were evaluated using logistic regression models.

Results

Seropositivity for Leptospira spp. was statistically different between groups: 7.2% (9/125) and 14.9% (17/114) in the H and KD, respectively (P = .05). The proportion of PCR‐positive cats was not. The most common serovars detected serologically were Pomona (n = 16) and Bratislava (n = 8). Risk factors for seropositivity included outdoor and hunting lifestyles (P = .03 and P < .001, respectively), the presence of another cat in the household (P < .01), and the sampling period, with the greatest number of cases identified between June and August (P =.02).

Conclusions

Seropositivity was significantly greater in KD cats, suggesting that the role of Leptospira spp. in KD in cats should be further investigated. The detection of urinary shedding of leptospires in several cats identifies a potential role in the transmission of the organism.     

Identification of Apoptotic Bodies in Equine Semen

Apoptosis in the testis is required to ensure an efficient spermatogenesis. However, sometimes, defective germ cells that are marked for elimination during this process escape elimination in the testes, giving rise to ejaculates with increased percentages of abnormal and apoptotic spermatozoa and a high percentage of apoptotic bodies. Apoptosis markers in the ejaculate have been associated with low fertility, either in animals or humans. Therefore, the goal of this study was to investigate whether fresh equine semen contains apoptotic bodies [initially named Merocyanine 540 (M540) bodies] and to study the relationship between the quantity of these bodies and cell concentration, the volume of ejaculate, viability and motility. Moreover, we also studied whether the presence apoptotic bodies in fresh semen was related to the resistance of the stallion spermatozoa to being incubated at 37°C or being frozen and thawed. Fresh equine semen was stained with fluorescent dyes such as M540 and Annexin‐V. Active Caspase 3 was studied in fresh semen through Western blotting and immunofluorescence with a specific antibody. Sperm kinematics was assessed in fresh, incubated and thawed samples using computer‐assisted semen analysis, and viability was evaluated with the LIVE/DEAD Sperm Viability Kit. Overall, our results demonstrate for the first time the presence of apoptotic bodies in equine semen. The quantity of apoptotic bodies was highly variable among stallions and was positively correlated with Caspase 3 activity in fresh samples and negatively correlated with the viability and motility of stallion spermatozoa after the cryopreservation process.     

Colloid Centrifugation Selects Normal Spermatozoa from Polymorphic Bull Ejaculates: A Case Study

Semen from a Western Finncattle bull exhibiting a highly polymorphic spermiogram was processed by colloid centrifugation using Androcoll‐B, a species‐specific silane‐coated silica colloid. In the first experiment, Single Layer Centrifugation (SLC) was used to identify which density colloids were needed to separate different cell populations. Colloids of the two chosen densities were then used in a density gradient resulting in two sperm subpopulations, one containing nearly all normally sized spermatozoa and the other enriched for the macrocephalic spermatozoa. Microcephalic spermatozoa did not appear in either of the selected subpopulations. Using a combination of SLC and DGC with this species‐specific colloid, it was possible to separate the spermatozoa into different subpopulations, that is, a subpopulation containing nearly all normally sized spermatozoa, and another one enriched for the macrocephalic spermatozoa. Thus, colloid centrifugation could be used to select sufficient normal spermatozoa from a highly polymorphic ejaculate for AI, if desired.     

Effect of Overnight Staining on the Quality of Flow Cytometric Sorted Stallion Sperm: Comparison with Tradtitional Protocols

Flow cytometry is considered the only reliable method for the separation of X and Y chromosome bearing spermatozoa in equines. The MoFlo SX DP sorter is highly efficient, allowing the production of foals of the desired sex. However, to achieve acceptable pregnancy rates the currently used protocol requires working with fresh semen obtained close to, or at, the sorting facility. An alternative protocol was tested during two consecutive breeding seasons. Fresh stallion semen was cooled for 20 h, during which staining with Hoechst 33342 took place. On the following day, this sample was flow sorted and compared with spermatozoa from the same ejaculate that had been sexed on the previous day. All sperm parameters evaluated remained unchanged when fresh sorted and refrigerated sorted semen were compared. Pre‐sorting storage at 5°C did not alter sperm velocities nor kinetics, viability or membrane permeability, production of reactive oxygen species, mitochondrial membrane potential or DNA fragmentation index of the sorted sample. The findings open for the possibility of using semen from stallions housed far from the sorting facilities. Processed and stained sperm could be shipped refrigerated on the previous day, sorted and inseminated on the next day.     

Altered telomeres in tumors with ATRX and DAXX mutations

The proteins encoded by ATRX and DAXX participate in chromatin remodeling at telomeres and other genomic sites. Because inactivating mutations of these genes are common in human pancreatic neuroendocrine tumors (PanNETs), we examined the telomere status of these tumors. We found that 61% of PanNETs displayed abnormal telomeres that are characteristic of a telomerase-independent telomere maintenance mechanism termed ALT (alternative lengthening of telomeres). All of the PanNETs exhibiting these abnormal telomeres had ATRX or DAXX mutations or loss of nuclear ATRX or DAXX protein. ATRX mutations also correlate with abnormal telomeres in tumors of the central nervous system. These data suggest that an alternative telomere maintenance function may operate in human tumors with alterations in the ATRX or DAXX genes.     

Activity of CeOx and TiOx nanoparticles grown on Au(111) in the water-gas shift reaction

The high performance of Au-CeO2 and Au-TiO2 catalysts in the water-gas shift (WGS) reaction (H2O + CO-->H2 + CO2) relies heavily on the direct participation of the oxide in the catalytic process. Although clean Au(111) is not catalytically active for the WGS, gold surfaces that are 20 to 30% covered by ceria or titania nanoparticles have activities comparable to those of good WGS catalysts such as Cu(111) or Cu(100). In TiO(2-x)/Au(111) and CeO(2-x)/Au(111), water dissociates on O vacancies of the oxide nanoparticles, CO adsorbs on Au sites located nearby, and subsequent reaction steps take place at the metal-oxide interface. In these inverse catalysts, the moderate chemical activity of bulk gold is coupled to that of a more reactive oxide.     

Spontaneous vesicle formation in aqueous mixtures of single-tailed surfactants

Spontaneous, single-walled, equilibrium vesicles can be prepared from aqueous mixtures of simple, commercially available, single-tailed cationic and anionic surfactants. Vesicle size, surface charge, or permeability can be readily adjusted by varying the ratio of anionic to cationic surfactant. Vesicle formation apparently results from the production of anion-cation surfactant pairs that then act as double-tailed zwitterionic surfactants. These vesicles are quite stable in comparison to conventional vesicles prepared by mechanical disruption of insoluble liquid crystalline dispersions.     

Mutations in CIC and FUBP1 contribute to human oligodendroglioma

Oligodendrogliomas are the second most common malignant brain tumor in adults and exhibit characteristic losses of chromosomes 1p and 19q. To identify the molecular genetic basis for this alteration, we performed exomic sequencing of seven tumors. Among other changes, we found that the CIC gene (homolog of the Drosophila gene capicua) on chromosome 19q was somatically mutated in six cases and that the FUBP1 gene [encoding far-upstream element (FUSE) binding protein] on chromosome 1p was somatically mutated in two tumors. Examination of 27 additional oligodendrogliomas revealed 12 and 3 more tumors with mutations of CIC and FUBP1, respectively, 58% of which were predicted to result in truncations of the encoded proteins. These results suggest a critical role for these genes in the biology and pathology of oligodendrocytes.     

Growth and yield of paddy rice as affected by tillage and nitrogen levels

Although tropical wetlands are rapidly being developed for the needed increase in rice (Oryza sativa L.) production, knowledge is still limited concerning the optimum soil and crop management practices. A study was thus carried out to evaluate the effects of different tillage systems on the growth and yield of paddy rice, grain yield response to N applications, and weed control. Five experiments were conducted for three consecutive seasons on hydromorphic soils (loamy and sandy loamy, mixed, isohyperthermic Aeric Tropaqualfs) at the International Institute of Tropical Agriculture, Ibadan, comparing the effects of zero tillage (without dry tillage and puddling) and conventional tillage (dry tillage and puddling) at two or more N levels. In two of the above experiments the effects of either two moisture regimens or chemical versus manual weed control were also evaluated.In four experiments there were no statistically significant differences in grain yield between zero-tillage plots sprayed with paraquat and conventional-tillage plots. Only in Experiment 2 did zero-tillage (with paraquat) plots give a significantly lower yield than conventional-tillage plots (5200 versus 5580 kg ha^?1, respectively) but the difference could be explained by greater rat damage in the former. The highly significant response in grain yield to N applications in all five experiments was statistically similar under both tillage systems. The continuous flooding treatment (Experiment 1) gave better weed control and higher grain yield than the saturation moisture regime (6150 versus 5420 kg ha^?1 grain yield). In zero-tillage plots where weeds were slashed before transplanting (Experiment 2), grain yield was lower and the weed growth greater than in zero-tillage and low N level. Satisfactory weed control was obtained with paraquat and continuous flooding.