A preliminary study of the adsorption and release of preservatives by contact lenses and collagen shields.

PURPOSE: We evaluated the adsorption and release of preservatives and a beta-blocking agent (metipranolol) by three different contact lens materials and two collagen shields. METHODS: We recorded the ultraviolet absorption spectra of these materials before, during, and after extended exposure to pharmaceutical preparations of artificial tears, beta-blocking eye drops, and a contact lens cleaning solution. The presence of preservatives and active ingredients was demonstrated by thin layer chromatography. RESULTS: Significant differences were observed depending on the nature of the absorbant materials and the preservatives. Soft lenses showed the greatest affinity for benzalkonium chloride and metipranolol but also readily released them. CONCLUSIONS: This preliminary study points out that rinsing with a sodium chloride isotonic solution without preservatives has an important place in daily contact lens care.

[Treatment of dry eye syndrome with lacrimal gel: a randomized multicenter study]. / Traitement de la sécheresse oculaire par gel lacrymal: étude multicentrique randomisée.

The appearance on the French market of a carbomer tear substitute, Gel-Larmes, an original galenic form, constitutes a real therapeutic progress in the treatment of dry eye syndrome. An open randomized multicentric trial was conducted comparing the tolerance and efficacy of Gel-Larmes with those of eye drops containing chondroitin sulphate. The statistical analysis evidences an inferior average number of daily instillations for Gel-Larmes, its better efficacy on the symptoms as well as on the objective criteria: biomicroscopic examination, break-up time, rose Bengal test. The tolerance of the product is excellent and 81% of the patients express their wish to pursue Gel-Larmes versus 54% for the reference product.

[Intraindividual double-blind comparative study of the immediate ocular tolerability of the Na+ and Mg++ salts of N-acetyl-aspartylglutamic acid (NAAGA)]. / Etude comparative intra-individuelle en double-insu de la tolérance oculaire immédiate des sels de Na+ et de Mg++ de l'acide N-acétyl-aspartyl-glutamique (NAAGA).

A good immediate ocular tolerance of eye-drops is paramount for the patient's compliance, and therefore for the therapeutic success. The tolerance of a new formula of NAAXIA, an anti-allergic eye-drop, whose sole modification was the replacement of the Mg++ ion by the Na+ ion, was compared with the previous formula. One drop of each preparation was instilled in one eye so as to make an intraindividual comparison. Just after instillation, each subject was asked to express what he felt, and which eye-drop he preferred. The answers, reported on a sequential analysis graph, clearly show that in all three groups (healthy adults, red-eyed adults, red-eyed children) the slight alteration of the formula led to a marked improvement in immediate tolerance.

X-ray attenuation properties of radiographic contrast media.

A systematic study has been carried out to assess the x-ray attenuation properties of various elements when used as radiographic contrast enhancing media. This study examines the effects of solutions of molecules with effective atomic numbers from 40 to 92 on the signal-contrast ratio of radiographic images formed with various input x-ray spectra on suitable phantoms. A variety of x-ray spectra were used including monoenergetic spectra, constant potential x-ray tube spectra, and computed tomography spectra. In addition, a computer model was used to predict the effects studied. In general, the computer model is able to accurately predict the resulting signal-contrast ratio for a given combination of contrast media, input x-ray spectra, and phantom composition. From these data and calculations, it may be possible to design new contrast media which are tailored to specific diagnostic imaging tasks.

Z helix-coil transition of d(C-Br8G-C-G-C-Br8G) studied by CD, 1H-NMR and IR spectroscopies.

The conformation of d(C-Br8G-C-G-C-Br8G) in aqueous solution was studied by CD and 1H-NMR spectroscopy and in condensed phase by IR spectroscopy. Whether in 0.1 M or 3 M NaCl solution or in film the only double helical structure adopted by brominated d(C-G)3 oligomer is the Z form. The IR spectrum of the film presents all the characteristic absorptions of the Z conformation and in particular is indicative of a syn conformation for the central guanosine as well as for the brominated one. Imino proton resonances of d(C-Br8G-C-G-C-Br8G) demonstrating the duplex formation were observed up to 60 degrees C. It is interesting to note that the significant highfield shifts of the dC H5" exocyclic sugar protons characteristic of the non exchangeable proton spectra of d(C-G)3 containing 5-methyl dC residues in the Z form were also detected in the proton spectrum of brominated oligomer. Whereas formation of the Z helix of methylated d(C-G)3 oligomers dependent on the salt concentration was found to occur via the preliminary formation of a B helix even in 4 M NaCl solution, the Z helix of d(C-Br8G-C-G-C-Br8G) is obtained directly from the coil form. However, IR data suggest that in the Z form of d(C-Br8G-C-G-C-Br8G), the overlapping of the base planes should be slightly different in comparison with the stacking observed in d(C-G)3 crystals. The kinetic data (activation energy and lifetime) of the Z helix-coil transition of brominated d(C-G)3 are compared to those of the B helix-coil transition observed for methylated d(C-G)3 in 0.1 M NaCl solution while the thermodynamic data of these two reactions (enthalpy and midpoint temperature) are slightly different.

[N-acetyl-aspartylglutamic acid eye drops in allergic-type conjuctivitis. Double-blind comparative clinical study]. / L'acide N-acetyl aspartyl glutamique en collyre dans les conjonctivites de type allergique. Etude clinique comparative en double insu.

Fifty patients with allergic conjunctivitis were included in a double-blind randomized clinical trial designed to compare the efficiency and tolerance of two antiallergic eye-drops: one containing NAAGA (22 patients), the other one containing disodium Cromoglycate (28 patients). Both treatments were used at a dosage of 1 drop 4 times per day. Ocular symptoms, conjunctivo-corneal signs and the subjective ocular condition assessed by the patients themselves with visual analogue scales, were all significantly improved by both eye-drops during the first month of treatment. Statistical analysis showed that patient ocular condition improved more rapidly with NAAGA eye-drops. In 25 patients (12 in the NAAGA group and 13 in the Cromoglycate group), the study was continued for an additional month according to a cross-over protocol. During the 2nd month of treatment, additional improvement of ocular symptoms and signs were observed with both eye-drops but more markedly in those patients who received NAAGA after Cromoglycate. Ocular tolerance was good for both eye-drops.

Oxprenolol placental transfer, plasma concentrations in newborns and passage into breast milk.

Thirty-two pregnant hypertensive patients were treated with oxprenolol administered in combination with dihydralazine as Trasipressol tablets. Before delivery, oxprenolol was demonstrable in the maternal plasma and the amniotic fluid. The free fraction of oxprenolol in the maternal serum (15% +/- 7.8; mean +/- s.d.; n = 25) was similar to that in normal serum. At the end of delivery, oxprenolol was found in both the maternal and umbilical plasma in most cases. Measurable, but low oxprenolol concentrations were present in the newborn plasma. After delivery, oxprenolol was demonstrable in the maternal plasma and breast milk. An infant weighing 3 kg and consuming 500 ml of breast milk per day would receive a maximum dose 60 times less than the normal daily dose for a hypertensive adult (4 mg/kg).

[3 new cases of pregnancy of the uterine horn]. / A propos de trois nouveaux cas de grossesse de la corne utérine.

Three new cases of pregnancy in the uterine cornu are described. Three types of localisation are grouped under this heading : interstitial pregnancies, intra-mural pregnancies and angular pregnancies which all have identical mechanisms of pathogenesis (uterine scars) and identical patterns of clinical progression (complicated by uterine rupture). The authors discuss the methods of diagnosis. A constant feature is pain with an asymmetrical uterus. Laparoscopy is often able to make the diagnosis of pregnancy in the uterine cornu, without being able to determine the exact site. Early diagnosis results in conservative surgical treatment.

[Echographic detection of cervical incompetence. Comparison between the abdominal and perineal route]. / Dépistage échographique de la béance isthmique. Comparaison entre la voie abdominale et la voie périnéale.

Ultrasonographic measurements of the cervix in perineal and abdominal projections were compared in 61 women. Measured by the abdominal route the diameter of the internal os in most cases exceeded by 4 mm that measured by the perineal route, and cervical incompetence can be diagnosed when the internal os is equal or superior to 24 mm. For the abdominal measurement to be reliable the posterior vesical angle must be well marked, which means that the bladder must be moderately filled.

[The cervix in primiparous women. A series of 320 perineal echographies]. / Le col de la primipare. Une série de 320 échographies périnéales de principe.

Perineal ultrasound was carried out on a series of 320 primiparous women at their first antenatal visit. The results obtained show that an internal of that was larger than 20 mm was abnormal. A sign of a short cervix (less than 40 mm long on ultrasound) was of not much value but had to be taken notice of. In six cases it was found that clinically the cervix was absolutely normal and on ultrasound was incompetent.