Doppler findings and tocolytic effect of transdermal glyceryl trinitrate and intravenous ritodrine as tocolysis of preterm labor / 대한산부인과학회잡지

OBJECTIVE: This study was conducted to compare the safety and efficacy of transdermal glyceryl trinitrate (GTN) in initial therapy for preterm labor with those of intravenous ritodrine hydrochloride and the effects of tocolytics in uteroplacental circulation, as assessed by uterine artery doppler velocimetry. METHODS: Patients between 24 and 34 weeks gestation with documented preterm labor were randomly assigned to receive transdermal GTN (n=24) or intravenous ritodrine (n=35) as initial tocolytic therapy. Patients in the GTN group were administered 0.2 mg/h released transdermal patch on the pregnant women's abdomen directly. Patient in the ritodrine group were treated 0.025 mg/min as initial dose. The dose increased at 15 minute intervals until uterine contractions were inhibited or side effects become intolerable. The maximum recommended dose was 0.20 mg/min. The main outcome examined were failure of tocolysis, time to uterine quiescence, time gained in utero, and frequency of adverse effects. We obtained both right and left uterine artery doppler velocity waveform before and after tocolytics therapy. The mean values of the right and left uterine artery systolic and diastolic ratio were calculated and used for analysis. RESULTS: There were no significant difference in maternal demographic between the groups. Successful tocolysis was observed in 79.2% in the GTN group, and 85.7% in the ritodrine group (p=0.726). Time to uterine stop contraction was 5.5 +/- 5.3 hr in ritodrine group and 1.1 +/- 0.3 hr in GTN group. There were no different in time to gain in uterus between the two groups. The patient in the ritodrine group had more adverse side effects, mainly maternal tachycardia (p=0.002), chest pain and tremor (p=0.035). There was no significant difference in uterine S/D ratios between the pretherapy and posttherapy GTN group. However, we found statistically significant difference between the pretherapy and 24 hr-posttherapy in ritodrine group. CONCLUSION: Transdermal GTN was effective, safe, and well tolerable tocolytic agent. Patients who received ritodrine hydrochloride were more likely to have adverse effects. We also conclude that GTN do not affect uteroplacental circulations as measured by S/D ratios but ritodrine does. This results suggest that progressively increasing dose of ritodrin and GTN maybe associated with a statistically significant decrease S/D ratios. However, further investigations needs to be performed.

Extracellular Matrix in Human Trabecular Meshwork

This study was performed to evaluate the distribution of extracellular matrix in the normal human trabecular meshwork. The trabecular meshworks obtained from 5 enucleated eyes due to traumatic eye-ball rupture were frozen processed, stained with monoclonal antibodies for fibronectin and type IV collagen, and observed by fluorescent microscopy. The indirect immunofluorescent study showed strong positive reactions in the subendothelial basement membrane for fibronectin and type IV collagen and negative reaction in the central core of trabecular beam. These results suggest that fibronectin and type IV collagen distribute predominantly in the basement membrane of the trabecular beam.

Histochemical Electron Microscopy of Conjunctival Surface in Dry Eye Syndrome

This study was performed to evaluate the histochemical changes of the conjunctival epithelial cell in eyes with dry eye syndrome. The authors selected 10 eyes clinically diagnosed as dry eye syndrome and 2 eyes which were enucleated due to choroidal melanoma as control group. The conjunctiva was stained with ruthenium red to enhance the detection of glycoprotein in conjunctival epithelium and observed by electron microscopy. The conjunctiva with dry eye syndrome showed the epithelial stratification, elon gation of the epithelial cells, reduction of microplicae in number, and irregular distribution of mucin. These results suggest that the mucin in the conjunctiva with dry eye syndrome may be abnormal in function and may lead to clumping.

Outflow of Aqueous Humor Following Cyclodialysis or Ciliochoroidal Detachment in Rabbit

Cyclodialysis and ciliochoroidal detachment was performed in one eye of three rabbits and in one eye of another three rabbits respectively. 0.1 ml of 10% sodium fluorescein was injected intracamerally after aspiration of aqueous humor and the eyeball was enucleated between 30 minutes and one hour after sodium fluorescein injection and prepared for fluorescence microscopy. Sodium fluorescein concentration in supraciliary space was much greater in group with cyclodialysis or ciliochoroidal detachment than in normal control group. These results suggest that in the eye with cyclodialysis, aqueous humor may gain access freely to supraciliary space through the cleft between anterior chamber and supraciliary space and then is removed rapidly and in the eye with ciliochoroidal detachment, aqueous humor may pass through uveoscleral outflow pathway.