Effect of temperature - humidity index on the onset of post- partum ovarian activity and reproductive behavior in Bos indicus cows

The effect of climatic factors on ovarian activity and reproductive behavior (RB) was evaluated in 46 Bos indicus cows kept under grazing conditions. Temperature-humidity index (THI) was used as an indicator of stress and divided in alert, damage and emergency levels. Fat thickness (FAT) was taken during the last trimester of gestation (LTG) to approximately 90d postpartum (PP). At 30d PP animals received a progesterone (P₄)-releasing device (CIDR) which was withdrawn 9d later. Ovarian activity was assessed by blood progesterone on days 21, 24, 27, 30, 49, 51, and 54 PP. Animals were divided into three groups, higher, and moderate RB and non-behavior. Sixty percent presented a THI >74 increasing dramatically from June to September up to >78. During LTG, animals lost 27% of their body reserves contrasting to PP where an increase of 2.6% (P=0.002) was observed. The percentages of cyclic and non-cyclic animals were 57 and 43%, respectively (P> 0.05). Seventy-two percent displayed RB and 28% were non-behavior (P<0.05). A negative correlation (r = -0.307; P = 0.038) between THI and RB, and a positive correlation (r = 0.427; P = 0.003) between the onset of ovarian activity and RB were observed. Differences in THI during the LTG (P<0.01) were observed between cyclic and non-cyclic animals. Non-behavior cows in the LTG had a higher THI (P <0.05). High levels of THI have a negative effect on the resumption of ovarian activity and RB in Bos indicus especially if high THI occurs during the last trimester of gestation.

[Pars plana vitrectomy, phacoemulsification and intraocular lens implantation for the management of cataract and proliferative diabetic retinopathy: comparison of a combined versus two-step surgical approach]

PURPOSE

To report the intra-and postoperative complications and visual acuity outcomes in pars plana vitrectomy (PPV), phacoemulsification and intraocular lens (IOL) implantation in patients with cataract and proliferative diabetic retinopathy (PDR). A comparison of the combined versus two-step surgical approach is given.

METHOD

Retrospective uncontrolled interventional clinical trial. Forty-eight eyes of 48 consecutive patients with PDR were included. Twenty-eight (58.3%) eyes with combined surgery and 20 (41.7%) eyes with sequential surgery were analyzed.

RESULTS

Postoperative follow-up time was between 6 and 63 months (mean: 18 months). 1) Combined surgery: Preoperative best-corrected visual acuity (BCVA) ranged from 20/200 to hand motions, and postoperative BCVA ranged from 20/30 to hand motions. BCVA improved in 17 eyes (60.7%), while in 7 (25%) eyes there was no change (> or =2 ETDRS lines) in VA, and in 4 (14.3%) eyes BCVA decreased. Postoperative complications included vitreous hemorrhage (VH) in 10 (35.7%) eyes, and fibrinous exudation in 9 (32.1%) eyes. 2) Two-step surgery: Preoperative BCVA ranged from 10/200 to light perception, and from 20/40 to light perception in the postoperative period. Best-corrected visual acuity improved in 15 (75%) eyes, remained the same in 4 (20%) eyes, and decreased in 1 (5%) eye. Postoperative complications included fibrinous exudation in 6 (30%) eyes, and VH in 3 (15%) eyes.

CONCLUSION

Combined PPV, phacoemulsification and IOL implantation as well as the two-step procedure are safe and effective for the management of cataract in PDR. Sequential surgery could be advantageous to BCVA outcomes by minimizing postoperative VH, which is significantly more frequent after combined surgery.

Prevention of suckling improves postpartum reproductive responses to hormone treatments in Pelibuey ewes

To determine the effects of suckling on postpartum (pp) reproductive efficiency in Pelibuey ewes, two experiments were performed. In Experiment 1, 112 ewes were randomly assigned to one of two groups at parturition: Without restriction of suckling (WRS) 24 h day(-1) for 60 days (n=56), and Weaned Ewes (WE), weaned at 40 days pp (n=56). On Day 30 pp, all ewes were given Prostaglandin (PGF2alpha) and one of four treatments (n=14): T1, intravaginal progestagen (FGA; 40 mg) for 12 days from day 30 pp+equine chorionic gonadotropin (eCG; 300 UI) until 2 days before removing FGA; T2, FGA was applied for 12 days; T3, a second application of PGF2alpha was given on day 40 pp+eCG on the same day; T4, a second injection of PGF2alpha was applied on day 40 pp only. In all the analyzed characteristics, the best results were obtained in WE. Within the WE group, the best treatment (P<0.05) was T1 with 85.7% of the ewes in oestrus, 71.4% pregnant and a prolificacy of 1.9. Within the WRS group the best results were observed in T1. In both groups, the lowest results (P<0.05) were obtained in T4. In Experiment 2, 75 ewes were randomly assigned to one of three groups (n=25) immediately after parturition: Group 1, Without restriction of suckling (WRS, as in Experiment 1); Group 2, with restriction of suckling (RS; suckling for 30 min day(-1)); Group 3, Early Weaning (EW: at 7 days pp). All ewes were given PGF2alpha at 30 days pp and the same hormonal treatment, FGA for 12 days+PGF2alpha and eCG 2 days before removing FGA. No differences were observed (P>0.05) between RS and EW for the presentation of oestrus (96% vs. 92%), pregnancy (72% vs. 76%) or prolificacy (1.9 vs. 1.9), although group WRS did not perform (P<0.05) as well as groups RS and EW for any measure of performance. In conclusion, the combination of hormonal treatment (FGA plus eCG) with weaning at 7 or 40 days pp, or restricted suckling, improves postpartum reproductive efficiency in Pelibuey ewes, demonstrating the inhibitory role of suckling on postpartum reproduction in this breed.

Localization of the initial developmental stages of Loma salmonae in rainbow trout (Oncorhynchus mykiss)

The intracellular microsporidian parasite Loma salmonae affects salmonids of the genus Oncorhynchus and is a significant cause of economic losses in pen-reared Chinook salmon (O. tshawytscha) in British Columbia. Loma salmonae infection is easily recognized by the xenomas that form in the gills, but early stages of infection are difficult to detect in histologic sections. In situ hybridization (ISH), using an L. salmonae-specific digoxigenin-labeled single-stranded DNA probe, was used to detect the parasite during the early stages of infection. Loma salmonae was detected in the gut mucosal epithelium as early as 24 hours postexposure (PE), and it localized in the lamina propria of the intestine within 24 hours of infection. After the parasite was detected in the lamina propria, dividing merogonic stages in infected cells in the heart were detected by ISH as early as 2 days PE, providing the first evidence of parasitaemia and hematogenous distribution of this parasite in infected blood cells. The parasites inside the infected cells appeared to be undergoing merogony as they passed through the heart, indicating that proliferation may start at the site of infection, before the parasite arrives to the gills for their final developmental phase. This is the first time that L. salmonae passage through the intestinal wall and migration to the heart has been visualized; however, the identity of the cells harboring the parasite has yet to be determined.

[Pigment dispersion syndrome in a patient with megalocornea]

CASE REPORT

A case of a patient of 12 years old with megalocornea and bilateral pigment dispersion syndrome is reported. An ultrasound biomicroscopic study was performed with the UBM 840 (Zeiss-Humphrey, 50 MHz) and an iris concavity with an iridolenticular and iridozonular contact was observed. A new exam after pilocarpine instillation drops showed the resolution of the iris concavity, zonular and lenticular contact.

DISCUSSION

The anterior chamber configuration of this patient analyzed with ultrasound biomicroscopy allowed us to understand the mechanism of the pigment dispersion syndrome.

[Long-term follow up of patients with nodal reentry tachycardia who had undergone radiofrequency ablation]

INTRODUCTION

The aim of this study was to assess the long term results (minimum of 3 years) of radiofrequency catheter ablation in patients with common (slow-fast) atrioventricular nodal reentrant tachycardia.

PATIENTS AND METHODS

Sixty consecutive patients (mean age 56 +/- 16 years, range 14 to 83, 16 men and 44 women) underwent slow pathway (n = 51, Group A) or fast pathway (n = 9, Group B) radiofrequency catheter ablation between January 1992 and March 1994. All patients were followed at 1, 3, 6 and 12 months after ablation with serial examinations and electrocardiograms and the last follow-up was made on April 1997.

RESULTS

During a mean follow-up period of 48 +/- 7 months (range 38 to 63) all evaluated patients remained asymptomatic. Eight recurrences were observed at a mean of 1 +/- 2 months (range, 0.5 to 7) after a successful ablation procedure. A second procedure was effective in eliminating the dual atrioventricular nodal pathway in each of them. In Group A patients, the pre-ablation PR interval, at 12 months after ablation and at last follow-up were 122 +/- 11, 124 +/- 13 and 124 +/- 15 ms, respectively. In Group B patients, the pre-ablation PR interval, at 12 months after ablation and at last follow-up were 130 +/- 24, 200 +/- 12, 200 +/- 24 ms, respectively. No significant atrioventricular conduction disturbances in any patient were observed. One patient developed a new onset left bundle branch block and 4 patients died of noncardiac causes.

CONCLUSIONS

In patients with atrioventricular nodal reentrant tachycardia, radiofrequency catheter ablation is a safe and effective therapy, with substantial good results that persist during long term follow-up, with a low recurrence rate and without complications during short and long term outcome.

Incidence and prognostic significance of right bundle branch block in patients with acute myocardial infarction receiving thrombolytic therapy

We assessed the incidence and prognostic significance of right bundle branch block (RBBB) in patients with acute myocardial infarction (AMI) receiving thrombolytic therapy. A prospective, one-year follow-up study involving 681 consecutive patients treated with thrombolytic agents for AMI was performed. Seventy-four patients developed RBBB (46% new-onset, 24% old and 30% indeterminate). RBBB was more common in older patients with large anterior AMI. New-onset RBBB were often transient (56%) and 84% of them resolved within 12 h after admission. Complicating events during the hospital phase, such as ventricular arrhythmias and development of heart failure, were more frequent in patients with RBBB. In-hospital and one-year mortality were higher in patients with RBBB (22.9 and 40.5% compared to 7.9 and 12.3% respectively in patients without block, both p<0.001). New-onset, non-transient RBBB were associated with the highest mortality rates (73% at one-year follow-up). By multivariate analysis, RBBB was retained as independent predictor of in-hospital and one-year mortality. We conclude that new-onset RBBB in patients receiving thrombolytic therapy for AMI is often transient. The development of RBBB has a negative and independent prognostic impact on the survival during the hospital phase and at one-year follow-up.

Characterization of telomeric regions from Ustilago maydis

The isolation of telomeres from the phytopathogenic fungus Ustilago maydis is described. The telomeric repeat from the plant Arabidopsis thaliana, TTTAGGG, cross-hybridizes to Bal31-sensitive fragments of U. maydis DNA and detects many or all of the U. maydis chromosomes separated by pulsed-field gel electrophoresis (PFGE). This telomeric repeat was used to screen a library enriched for chromosome ends. Three clones were isolated which contained the tandemly repeated sequence TTAGGG. This sequence is identical to some known telomere repeats found in humans and other vertebrates as well as in some protozoa and moulds. In addition, the three telomeric clones had an almost identical 376 bp segment of middle-repeated telomere-associated sequences adjacent to the telomeric repeat. This segment hybridized to many or all U. maydis chromosomes separated by PFGE and showed a hybridization pattern in genomic digestions similar to that of the telomeric repeat. These results indicate that in U. maydis the same segment of telomere-associated sequences is located adjacent to the telomeric repeat in many or all chromosomes, which suggests that it may have a common role in chromosome function.