Effects of gentamicin sulfate on the contractility of myometrium isolated from non-pregnant cows

A novel approach in the prevention of mastitis: electrical teat dipping

Teat dipping is widely used in dairy cattle, especially to protect against contagious mastitis. Here we determine the effect of the device called 'Electrical Teat Dipping' (ETD), which was developed by combining teat dipping application and electrical field stimulation technique on teats. For this purpose, the front teats of 100 Holstein breed milking cows were evaluated in two groups, with ETD being applied once to the left front teat of these cows, and conventional teat dipping (CTD) being applied once to the right front teat, both after milking. Ultrasonographic measurements of the teats were made before milking and after teat dipping. We found that the width of the teat canal (1.88 ± 0.07 mm) in the teat using ETD was narrower after the application compared to those with CTD (2.28 ± 0.05 mm). Based on our findings, we conclude that the effects of ETD on the teat are very positive and can potentially be used as a new approach in the preventative control of mastitis in cows.

Serum biochemical profile in buffalo endometritis and impact of treatment with PGF2α and intrauterine gentamicin infusion on postpartum reproductive performance

Improving reproductive performance of repeat breeder buffalo cows due to clinical endometritis is crucial in overcoming infertility problems in buffalo cows. The aim of the present study was to use PGF2α and/or gentamicin 10% for treatment of endometritis and to determine biochemical parameters in serum that could be used to diagnose endometritis in buffalo cows. A total of 64 anestrous buffalo cows were assigned into one of five treatment groups: group one (n = 9) buffalo cows were physiological normal cows and served as a control group; group 2 buffalo cows had endometritis, but were not treated (n = 10); group 3 buffalo cows had endometritis and were treated with intrauterine delivery of 100 ml of a 10% gentamicin sulfate solution in three times within 1 week (n = 15); group 4 buffalo cows received two I.M. doses of PGF2α (2 ml Estrumate IM) at the time of corpus luteum dominance (n = 15) (treatment 4 does not make sense as you stated that the cows were in anestrus) on the ovary; group 5 buffalo cows received two IM doses of PGF2α at an 11 day interval and the 10% gentamicin solution as described for group 3. Serum samples were collected from control, pre-treated, and post-treated buffalo cows with endometritis to evaluate the diagnostic biochemical parameters. The days to first estrus (DFE), number of services per conception (S/C), days open (DO), and pregnancy rate (Preg) were the measures for determining reproductive performance for the buffalo cows. The buffalo cows treated by gentamicin and PGF2 exhibited their first estrus earlier than cows in the other four groups of cows. The number of days open for control cows was greater (P < 0.05) than for the other groups and the control cows, as were the number of services per conception (P < 0.05) and pregnancy rate (30%: P < 0.05). The receiver operating characteristic (ROC) curve was used to identify biochemical parameters in serum to predict endometritis. Creatine kinase (CK), aspartate aminotransferase (AST), and concentrations of total bilirubin and immunoglobulins in serum were greater (P < 0.05), while serum albumin values were lower (P < 0.05) in serum of buffalo cows with endometritis. From the ROC analyses, CK was the most predictable biomarker for endometritis with an area under the curve of 0.889, sensitivity of 80%, and specificity of 100% (P < 0.001). In conclusion, the use of gentamicin and PGF2 for treatment of endometritis improves the reproductive performance of buffalo cows, and concentrations of CK serve as an aid for diagnosing endometritis.Graphical abstract.

Glomerular nephrotoxicity of aminoglycosides

Aminoglycoside antibiotics are the most commonly used antibiotics worldwide in the treatment of Gram-negative bacterial infections. However, aminoglycosides induce nephrotoxicity in 10-20% of therapeutic courses. Aminoglycoside-induced nephrotoxicity is characterized by slow rises in serum creatinine, tubular necrosis and marked decreases in glomerular filtration rate and in the ultrafiltration coefficient. Regulation of the ultrafiltration coefficient depends on the activity of intraglomerular mesangial cells. The mechanisms responsible for tubular nephrotoxicity of aminoglycosides have been intensively reviewed previously, but glomerular toxicity has received less attention. The purpose of this review is to critically assess the published literature regarding the toxic mechanisms of action of aminoglycosides on renal glomeruli and mesangial cells. The main goal of this review is to provide an actualized and mechanistic vision of pathways involved in glomerular toxic effects of aminoglycosides.

Inhibition of Staphylococcus aureus by H2O2-producing Lactobacillus gasseri isolated from the vaginal tract of cattle

Infectious diseases are the major reproductive complication during postpartum. The bacteria that colonize the postpartum uterus of cattle are specific as well as opportunistic pathogens that include Staphylococcus aureus. The antibiotics and antiseptic agents used in the treatment of postpartum acute infections induce residues in foods, spread of bacterial resistance, increase in financial costs and failures in defense mechanisms of the host. Preventive treatment with probiotic products could decrease the use of antibiotics in dairy farming systems. Lactobacilli are present in the vaginal microflora of healthy cows. They can prevent pathogen colonization by mechanisms such as the production of antagonistic substances as lactic acid, H2O2, or bacteriocins. The aim of the present study was the selection of H2O2 generating lactobacilli from a group of 72 strains isolated from the vagina of cattle. Both Lactobacillus gasseri CRL1421 and Lactobacillus gasseri CRL1412, which share some probiotic properties, produce H2O2, detected by the plate colorimetric method. They were chosen to study the kinetics of H2O2 production under different culture conditions. Both microorganisms produced greater amounts of H2O2 in aerated than in static cultures. As L. gasseri CRL1421 had a greater capacity to generate H2O2, associative cultures with this strain and S. aureus were conducted. A significant decrease in the growth of the pathogen was detected after culture for 6h, this effect being greater under aerated conditions. The addition of catalase to mixed cultures partially abolished the inhibition, an effect that could be attributed to the combined action of H2O2 and other antagonistic metabolites. The simultaneous addition of catalase and NaOH to these cultures restored S. aureus growth. This observation suggests that the inhibition was produced by the combination of H2O2 and lactic acid, both released by the lactobacilli. Electron microphotographs showed the damage caused by the lactobacilli supernatant on the pathogenic cells. The treatment of S. aureus with lactic acid and hydrogen peroxide evidenced that each metabolite produced a different type of morphological damage. The number of viable cells obtained agrees with the electron microscopy observations. The results support the idea that L. gasseri CRL1421 could be successfully included in a probiotic product to prevent S. aureus infection in cows.

Reproductive Tract Infections in Horses

Diagnosis, treatment, and, ultimately, prevention of reproductive disease are vital components of equine veterinary medicine. A thorough understanding of anatomy and physiology is necessary to reconcile the pathologic findings of disease. Only then can a rational treatment plan be formulated. Many recent advances in knowledge about the reproductive system of multiple species have application to the mare and stallion.

Contractile reactivity of human myometrium in isolated non-pregnant uteri

BACKGROUND

Perfusion of the isolated uterus has been shown to be a feasible experimental system for studies of the human endometrium and myometrium. Utilizing our established experimental perfusion model we perfused 20 uteri for 27 h and investigated the contractile reactivity of the myometrium in response to 17beta-estradiol (E2) and oxytocin (OT).

METHODS

Uteri of group A (n = 4) were stimulated with OT; group B (n = 4) was treated continuously with E2; group C (n = 4) received both E2 and OT for 27 h; group D (n = 4) was perfused for 27 h with E2 with the addition of OT for the last 3 h of the experiment; group E (n = 4) as control group remained without any treatment. The pressure and duration of uterine contractions were recorded during the entire perfusion period using intramural and endoluminal pressure catheters.

RESULTS

Compared to the other treatment groups and controls, the most effective myometrial activity was achieved in group D during the OT stimulation period. No relevant myometrial activity was detected in the control group.

CONCLUSIONS

Continuous E2 treatment, with the addition of OT for the last 3 h of the 27 h perfusion period, led to the most pronounced uterotonic effects in the presented experimental condition.