Improved Femtosecond Laser-Assisted Phacoemulsification of Hard Nucleus Cataract

Purpose: The development and clinical study of improved femtosecond laser-assisted phacoemulsification (PE) technology of hard nucleus cataract.Patients and methods. Improved femtosecond laser-assisted PE of hard nucleus cataract performed in 83 patients (93 eyes) (1st group), known femtosecond laser-assisted PE technique performed in 72 patients (78 eyes) (2nd group), torsional PE performed in 81 patients (89 eyes) (3rd group). The degree of intraoperative myosis, effective ultrasound time, corneal endothelial cell loss were evaluated in all groups.Results. Femtosecond laser-assisted PE is an effective technique for hard nucleus cataract removal, which can significantly reduce the energy ultrasonic load on the eye tissue. The proposed method for the instillation of prostaglandin synthesis inhibitors and the observance of the minimum possible interval between the first and second stages of the operation can prevent significant intraoperative narrowing of the pupil. A significant narrowing of the pupil by more than 2 mm after the femtolaser stage was noted in 7 (7.5 %) cases in the 1st group of patients, in 15 (16.9 %) cases in the 2nd group, in 5 (6.4 %) cases in the 3rd group. The results of the study has shown a significant decrease in the effective ultrasound time for a femtosecond laser-assisted PE compared with a torsional PE. The effective ultrasound time was in the 1st group (improved technology of femtosecond laser-assisted PE) — 3.81 ± 0.75, in the 2nd group (known technology of the femtosecond laser-assisted PE) — 5.23 ± 1.07 s (p < 0.05), in the 3rd group (OZil technology) — 8.67 ± 1.83 s (p < 0.05). The decrease in the effective ultrasound time has become a determining factor in reducing the loss of corneal endothelial cells in both femtosecond laser-assisted PE technologies compared to torsional PE. The average loss of corneal endothelial cells 3 months after surgery was 8.7 ± 1.8 % in the 1st group, 10.3 ± 2.1% in the 2nd group, 13.5 ± 2.7 % (p < 0.05) in the 3rd group of patients.Conclusion. The proposed improved technology contributes to the solution of some problems that characterize femtosecond laser-assisted PE, and also helps to reduce the effective ultrasound time and the loss of corneal endothelial cells.

Methods of prolonging a pregnancy threatened with preterm labour

Both prolonged and shortened pregnancies carry the risk of increased mortality of the offspring. The main causes of early delivery are genetic factors, bacterial and viral infections, corpus luteum insufficiency and pathologies of the placenta. Antepartum luteolysis is due to the activity of prostaglandin F2α. A decrease in the progesterone concentration activates the sensitivity of the uterine muscles to oxytocin. Calcium ions move into the myocytes and bind to calmodulin, starting enzymatic reactions necessary for muscle contraction. Oxytocin promotes prostaglandin F2α release. Cholesterol and magnesium stimulate the binding of oxytocin to its receptors. A premature delivery is caused by a disorder of the balance between contractility and relaxation of the myometrium, which is regulated by many signalling pathways. Birth in humans can be postponed by the use of many different tocolytic medications, β-adrenergic drugs (ritodrine, hexoprenaline, fenoterol, terbutaline), magnesium salts, prostaglandin synthesis inhibitors (indomethacin, naproxen), pentoxifylline, metoprolol, calcium antagonists – calcium channel blockers (nifedipine), oxytocine antagonists (atosiban), nitric oxide donors (nitroglycerin) as well as progesterone and its synthetic analogs. In dogs and cats, in the presence of endogenous hormone deficiency, progesterone and its derivatives (gestagens) are recommended. In small animals with the risk of premature delivery, terbutaline has successfully been used. Premature delivery is a serious problem in both human and veterinary medicine, and experience from human medicine is being gradually introduced into veterinary practice.

Interaction among beta-endorphin, nitric oxide and prostaglandins during ovulation in rats

The aim of this study was to investigate the relationship between beta-endorphin and nitric oxide (NO) during the ovulatory process in rats. Immature rats were treated with equine chorionic gonadotrophin-hCG to induce ovulation. An intrabursal injection of beta-endorphin stimulated nitric oxide synthase (NOS) activity. This effect was completely reversed when naltrexone was co-injected with beta-endorphin. The stimulatory action of beta-endorphin on NOS activity was studied to determine whether it was exerted via prostaglandins. Treatment with prostaglandin E(2) (PGE(2)) completely reversed the beta-endorphin-induced stimulation of NOS activity. Moreover, intrabursal injection of meloxicam, an inhibitor of cyclooxygenase 2, increased NOS activity, but this effect was not altered by co-injection with beta-endorphin. The presence of both endothelial NOS (eNOS) and inducible NOS (iNOS) in the ovary at 10 h after hCG treatment was studied by western blot analysis. Local administration of beta-endorphin inhibited the expression of eNOS protein, whereas expression of iNOS protein was not detectable. Ovarian beta-endorphin content was diminished at 10 h after hCG injection. Treatment with prostaglandin synthesis inhibitors in vivo augmented the ovarian beta-endorphin content. In conclusion, these results indicate that beta-endorphin stimulates the activity of ovarian NOS indirectly by inhibiting prostaglandin production.