Comparison of surgical outcomes of Carlevale sutureless scleral fixation and Artisan Aphakia intraocular lens.

PURPOSE: To compare intra- and postoperative results of sutureless scleral fixated Carlevale intraocular lens (IOL) with iris fixated Artisan IOL. METHODS: Monocentre, retrospective analysis of refractive outcomes and intra- and postoperative complications of patients who received a Carlevale or Artisan IOL between January 2019 and March 2022. RESULTS: 178 eyes of 169 patients were included (101 Carlevale and 77 Artisan IOLs). The standard follow-up time was 1 month. Two statistically significant differences were found: in the deviation of the postoperative spherical equivalent of the refraction from the preoperative chosen IOL target (p = 0.019; mean deviation was -0.46 in the Carlevale and 0.08 in the Artisan group), and the number of eyes with complications between the Carlevale and Artisan groups (p = 0.003; 33 in the Carlevale and 42 in the Artisan group). CONCLUSION: The current study is the largest so far comparing both refractive outcomes and complications after implantation of Carlevale and Artisan IOL. The Carlevale IOL does not carry a greater complication risk on the short-term follow-up. This provides additional evidence that the Carlevale IOL has to be added to the armamentarium of the ophthalmic surgeon.

Differential effects of muscle fibre length and insulin on muscle-specific mRNA content in isolated mature muscle fibres during long-term culture.

The aims of this study were (1) to determine the relationship between muscle fibre cross-sectional area and cytoplasmic density of myonuclei in high- and low-oxidative Xenopus muscle fibres and (2) to test whether insulin and long-term high fibre length caused an increase in the number of myonuclei and in the expression of alpha-skeletal actin and of myogenic regulatory factors (myogenin and MyoD) in these muscle fibres. In high- and low-oxidative muscle fibres from freshly frozen iliofibularis muscles, the number of myonuclei per millimetre fibre length was proportional to muscle fibre cross-sectional area. The in vivo myonuclear density thus seemed to be strictly regulated, suggesting that the induction of hypertrophy required the activation of satellite cells. The effects of muscle fibre length and insulin on myonuclear density and myonuclear mRNA content were investigated on high-oxidative single muscle fibres cultured for 4-5 days. Muscle fibres were kept at a low length (~15% below passive slack length) in culture medium with a high insulin concentration (~6 nmol/l: "high insulin medium") or without insulin, and at a high length (~5% above passive slack length) in high insulin medium. High fibre length and high insulin medium did not change the myonuclear density of isolated muscle fibres during culture. High insulin increased the myonuclear alpha-skeletal actin mRNA content, whereas fibre length had no effect on alpha-skeletal actin mRNA content. After culture at high fibre length in high insulin medium, the myonuclear myogenin mRNA content was 2.5-fold higher than that of fibres cultured at low length in high insulin medium or in medium without insulin. Myonuclear MyoD mRNA content was not affected by fibre length or insulin. These in vitro experiments indicate that high muscle fibre length and insulin enhance muscle gene expression but that other critical factors are required to induce adaptation of muscle fibre size and performance.

Effects of strain on contractile force and number of sarcomeres in series of Xenopus laevis single muscle fibres during long-term culture.

The aim of the present study is to test whether mechanical strain uniquely regulates muscle fibre atrophy/hypertrophy and adaptation of the number of sarcomeres in series within mature muscle fibres in vitro . Mature single muscle fibres from Xenopus laevis illiofibularis muscle were cultured (4-97 days) while kept at negative strain ( approximately 20% below passive slack length, 'short fibres') or at positive strain ( approximately 5% over passive slack length, 'long fibres'). Before and after culture the number of sarcomeres in series was determined using laser diffraction. During culture, twitch and tetanic force characteristics were measured every day. Survival time of long fibres was substantially less than that of short fibres. Of the long fibres 40% died or became inexcitable within 1 week, whereas this did not occur for short fibres. During culture, twitch and tetanic force of all short fibres increased substantially. Regression analysis showed that the post-culture number of sarcomeres in series was not significantly changed compared to the number before culture. It is concluded that culture at negative strain does not result in atrophy or a reduction of the number of sarcomeres in series, even after 97 days. For the long fibres we did not detect any hypertrophy as tetanic force remained stable or decreased slowly, while twitch force varied. Regression analysis of the change of the number of sarcomeres in series as a function of the culture time showed a positive slope ( P=0.054). Two out of four long fibres that were cultured for at least 2 weeks showed an increase in the number of sarcomeres of 4-5%. Compared with in vivo adaptation to mechanical stimuli this is much less than would be expected. The data suggest that strain may not be the only factor that regulates hypertrophy and the number of sarcomeres in series.

Determination of myoglobin concentration and oxidative capacity in cryostat sections of human and rat skeletal muscle fibres and rat cardiomyocytes.

Myoglobin plays various roles in oxygen supply to muscle mitochondria. It is difficult, and in some cases impossible, to study the relationship between the myoglobin concentration and the oxidative capacity of individual muscle cells because myoglobin has to be fixed in situ whereas determination of oxidative capacity, for example, succinate dehydrogenase activity, requires unfixed cryostat sections. We have investigated whether a vapour-fixation technique allows the use of serial sections to study the relationship between myoglobin and succinate dehydrogenase activity. The technique is used to study a rat soleus muscle, two human skeletal muscle biopsies and biopsies of two patients with chronic heart failure, and in a control and hypertrophied rat heart. Staining intensities were quantified by microdensitometry. The absorbance values were calibrated using sections cut from gelatine blocks containing known amounts of myoglobin. The results show that it is possible to use serial sections for the determination of the myoglobin concentration and succinate dehydrogenase activity, and indicate that myoglobin can lead to a substantial reduction (18-60%) of the extracellular oxygen tension required to prevent an anoxic core in muscle cells.

Confounding by contraindication in a nationwide cohort study of risk for death in patients taking ibopamine.

BACKGROUND: Outcomes may differ in treated and untreated patients because of a contraindication for treatment in the latter that is independently associated with the outcome of interest. OBJECTIVE: To evaluate the effects of confounding by contraindication on risk factors for death in patients taking ibopamine after its use was restricted in early September 1995. DESIGN: Retrospective cohort study. SETTING: The Netherlands. PATIENTS: 1146 patients with congestive heart failure who were prescribed ibopamine at least once and for whom medication history and medical data were available. MEASUREMENTS: Cardiovascular risk factors, clinical characteristics, and medication use. Each patient was assigned an index date (the date of death, or a random date for patients still alive at the end of the study). RESULTS: In univariate analyses comparing patients with an index date before and those with an index date after 8 September 1995, the relative risk for death associated with current use of ibopamine was 3.02 (95% CI, 2.12 to 4.30) compared with 0.71 (CI, 0.53 to 0.96), respectively. In multivariate analyses, the risk for death was 2.62 (CI, 1.76 to 3.90) and 0.93 (CI, 0.84 to 1.02), respectively. CONCLUSION: The marked inversion of the relative risk estimate can be considered a practical example of confounding by contraindication.

Twitch and tetanic tension during culture of mature Xenopus laevis single muscle fibres.

Investigation of the mechanisms of muscle adaptation requires independent control of the regulating factors. The aim of the present study was to develop a serum-free medium to culture mature single muscle fibres of Xenopus laevis. As an example, we used the culture system to study adaptation of twitch and tetanic force characteristics, number of sarcomeres in series and fibre cross-section. Fibres dissected from m. iliofibularis (n = 10) were kept in culture at a fibre mean sarcomere length of 2.3 microm in a culture medium without serum. Twitch and tetanic tension were determined daily. Before and after culture the number of sarcomeres was determined by laser diffraction and fibre cross-sectional area (CSA) was determined by microscopy. For five fibres twitch tension increased during culture and tetanic tension was stable for periods varying from 8 to 14 days ('stable fibres'), after which fibres were removed from culture for analysis. Fibre CSA and the number of sarcomeres in series remained constant during culture. Five other fibres showed a substantial reduction in twitch and tetanic tension within the first five days of culture ('unstable fibres'). After 7-9 days of culture, three of these fibres died. For two of the unstable fibres, after the substantial force reduction, twitch and tetanic tension increased again. Finally at day 14 and 18 of culture, respectively, the tensions attained values higher than their original values. For stable fibres, twitch contraction time, twitch half-relaxation time and tetanus 10%-relaxation time increased during culture. For unstable fibres these parameters fluctuated. For all fibres the stimulus threshold fluctuated during the first two days, and then remained constant, even for the fibres that were cultured for at least two weeks. It is concluded that the present culture system for mature muscle fibres allows long-term studies within a well-defined medium. Unfortunately, initial tetanic and twitch force are poor predictors of the long-term behaviour of the fibres.

Endocrinological studies with (7 alpha, 17 alpha)-17-hydroxy-7-methyl-19-norpregn-5(10)-en-20-yn-3-one (Org OD 14).

A novel steroid, (7 alpha, 17 alpha)-17-hydroxy-7-methyl-19-norpregn-5(10)-en-20-yn-3-one (Org OD 14), is described which has concomitant weak estrogenic, progestational and androgenic activities. This hormonal profile was demonstrated using various endocrinological tests and the results were evaluated in terms of well-known reference compounds. It has been well established that combinations of estrogens, androgens and progestagens exert positive or synergistic effects on certain target organs, e.g. the hypothalamic-pituitary axis, and antagonistic or complementary effects on others, e.g. on the endometrium. Org OD 14 with estrogenic, androgenic and progestational activities can therefore be expected to induce complex effects on various target organs. This explains the observed effects of the compound on hypothalamic-pituitary axis, bone-loss, endometrium and sexual behaviour.