Interaction of intraocular lenses with various concentrations of silicone oil: an experimental study

The aim of this study was to evaluate the interaction between various widely used intraocular lenses (IOLs) and silicone oils of different viscosities. Four groups of IOLs, including monoblock foldable hydrophilic acrylic IOLs (Morcher, type 92s); monoblock hydrophobic acrylic IOLs (Acrysof-SA60AT, Alcon); single-piece rigid polymethylmethacrylate (PMMA) IOLs (Intraocular Optical International-IOI-65130) and a three-piece foldable silicone optic IOL (CeeOn Edge 911A, Pharmacia UpJohn) were analyzed in vitro to determine the percentage adherence 1,000-centistoke, 1,300-centistoke or 5,000-centistokes silicone oil on the IOL optic. For each IOL type, there was no statistically significant difference in the mean silicone oil coverage (MSC) of the IOL optics for the different viscosities of silicone oil. Silicone IOLs had the highest MSC percentage (79.9%) whereas hydrophilic acrylic IOLs were the least silicone-covered IOLs (7.8%) compared to the other IOL types tested in this study. It is not the concentration of silicone oil that affects silicone oil coverage. When performing small-incision cataract surgery in patients who may require silicone oil injection, foldable hydrophilic acrylic or hydrophobic acrylic lenses should be preferred over standard foldable silicone lenses.     

Electrophysiological correlates of sensory innervation of the vesico-urethral junction and urethra in man

To investigate urethral sensory innervation in man, cerebral evoked potentials (CEPs) and bulbocavernous reflex (BCR) were recorded by stimulation of vesico-urethral junction (VUJ), prostatic and distal urethra, and penile skin. A specially produced catheter with a pair of electrodes was used for bipolar stimulation along the lower urinary tract. In comparison to the potentials evoked by distal urethral stimulation, the shape differences and protracted latency of CEPs to VUJ stimulation suggest that the distal and proximal urethra are innervated by different peripheral afferents. Similarities of CEPs and BCR latencies produced by prostatic urethral and VUJ stimulation indicate that the sensory innervation of the prostatic urethra is provided by pelvic nerve afferents. The remaining distal parts of the urethra are innervated by pudendal nerves. This is indicated by shape similarities and latency characteristics of both CEPs and BCR when the distal urethra and glans skin are stimulated.     

Psychological effects of tibolone and sequential estrogen-progestogen therapy in perimenopausal women.

OBJECTIVE: To investigate changes in psychological symptoms before and after continuous tibolone treatment and sequential estrogen-progestogen therapy in perimenopausal women. METHODS: In this prospective, randomized, controlled study, perimenopausal women were randomly allocated to treatment with either tibolone 2.5 mg/day for 28 days (n = 28), or 0.625 mg conjugated equine estrogens (CEE) for 25 days plus 5 mg medroxyprogesterone acetate (MPA) daily on days 16-25 (n = 33). The differences in Beck's depression scores and serum lipid profiles before and after 1 year of treatment with both regimens were compared. RESULTS: Both groups were similar with respect to demographic characteristics. The differences in Beck's depression scores before and after treatment were statistically significant in the tibolone group (21.3 vs 17.1, p = 0.038) and also in the group receiving standard sequential estrogen-progestogen treatment (15.7 vs. 13.0, p = 0.040). In the sequential estrogen-progesterone group, a statistically significant increase was measured in high-density lipoprotein (HDL)-cholesterol levels after treatment (49.1 vs. 56.8 mg/dl, p = 0.023). CONCLUSION: Tibolone is as effective as sequential estrogen-progesterone therapy in alleviating the psychological symptoms of the perimenopause. In addition, CEE + MPA induces favorable changes in HDL-cholesterol.     

Oral and facial representation in the trigeminal principal and rostral spinal nuclei of the cat

Transganglionic transport of horseradish peroxidase (HRP) was used to study the patterns of termination of somatic afferent fibers innervating oral and facial structures within the principal nucleus (Vp), nucleus oralis (Vo), and nucleus interpolaris (Vi). The primary trigeminal afferent fibers that innervate the oral cavity supplied by the pterygopalatine, superior alveolar, lingual, buccal, and inferior alveolar branches, as well as the facial skin supplied by the frontal, corneal, zygomatic, infraorbital, auriculotemporal, mylohyoid, and mental branches, were traced in this experiment. The results show that trigeminal afferent nerves that innervate the oral cavity project mainly to the principal nucleus, the rostrodorsomedial part (Vo.r) and dorsomedial division (Vo.dm) of pars oralis, and the dorsomedial region of pars interpolaris, while an extensive overlap of projections is found in the Vo.r, Vo.dm, and rostral Vi. The central processes of fibers innervating the anterior face (i.e., mental, infraorbital, and frontal nerves) terminate in the ventral division of principalis (Vpv), caudal region pars oralis (Vo.c), and ventrolateral Vi, with the largest numbers of terminals being found in the Vpv and Vi. In contrast, the central projection patterns of the corneal, zygomatic, mylohyoid, and auriculotemporal afferents are different from those of other afferent nerves examined, and present a discrete projection to the trigeminal sensory nuclear complex (TSNC). The corneal, mylohyoid, and auriculotemporal afferents mainly project to the restricted regions of principalis and caudal Vi, while zygomatic afferent nerve fibers project to the caudal third of pars interpolaris. The typical somatotopic organization with the face of the mouth open inverted is represented in the rostrocaudal midlevels of the Vpv and caudal pars interpolaris. The Vpd receives topographical projection from primary afferent nerves that innervate the oral structure only, while this projection was organized in a complicated manner. The relationship between the functional segregation and the cytoarchitectonic differentiation of the TSNC is discussed, particularly with respect to this somatotopic organization, combined with the characteristics of projecting cells in the TSNC.     

Contact lenses in the correction of childhood aphakia.

PURPOSE: To evaluate the results of extended-wear silicone contact lenses (Silsoft, Bausch & Lomb, Rochester, NY, U.S.A) after congenital cataract extraction. METHOD: Case records of congenital cataract extraction performed between 1992-1999, in the Department of Ophthalmology, Dokuz Eylül University School of Medicine, were retrospectively reviewed. Convenient-power extended-wear silicone contact lenses (Silsoft) were prescribed for patients 5 to 12 days after surgery. Patients were scheduled for follow-up control visits once per month in the first year, bimonthly in the second year, and quarerly visits thereafter. Visual acuity, fixation, binocularity, and deviation were checked at each follow-up visit. Examination of the cornea and the contact lens surface was also performed at each visit. RESULTS: A total of 51 children (83 eyes) were included in the study. Mean age was 19.4 +/- 18 months. Mean duration of contact lens wear per lens was 26 +/- 11 weeks. Contact lens wear was discontinued for 11 eyes: 6 because of unstable lens, frequent loss, and financial problems, and 5 were discontinued because of recurrent irritation and corneal infiltration. Mean contact lens usage time per patient was 5.8 years, and mean contact lens loss was 0.98 per year. Visual acuity improved in 58 (69.8%) eyes and remained unaltered in the remaining 25 eyes. CONCLUSION: Extended-wear silicone contact lenses offer a safe, easy treatment option for childhood aphakia, providing prolonged wearing time and low rates of complications and drop out.     

Pregnancy-associated plasma protein-A and asthma

Pregnancy-associated plasma protein-A (PAPP-A) is potentially a proatherosclerotic metalloproteinase and a new inflammatory marker. Investigators sought to evaluate the significance of PAPP-A in patients with asthma. Blood samples were collected from 35 patients and 20 control subjects. Serum PAPP-A was determined by enzyme-linked immunosorbent assay. PAPP-A levels of patients with asthma (8.1±5.0 mU/L) were higher than those of the control group (4.9±2.1 mU/L) (P < .01). A significant correlation was noted between serum PAPP-A concentration and asthma severity (r=.581;P < .01). Investigators concluded that PAPP-A may contribute to airway smooth muscle hyperplasia as an insulin-like growth factor-dependent insulin-like growth factor-binding protein-4 protease in patients with asthma.     

IMPACT OF HEPARIN LOCKING FREQUENCY ON PREVENTING TEMPORARY DIALYSIS CATHETER DYSFUNCTION IN HAEMODIALYSIS PATIENTS

A prospective analysis was conducted comparing dysfunction attributable to catheter thrombosis in subjects who received a heparin catheter lock three times a week (n = 15) to those who received a heparin lock six times a week (n = 15) immediately after the insertion of a temporary haemodialysis catheter. Thrombus related catheter removal occurred in two patients in control but no patients in the experiment group. Heparin locking six times a week was found to be effective in prolonging the mean of the first day where difficulty was experienced in aspiration. It also prevented any possible difficulty in catheter flushing. Increased locking frequency prevents any thrombus accumulation within the temporary catheter, while it has limited but significant preventive effect on thrombus accumulated around the catheter.     

Impairment of flow-mediated vasodilatation of brachial artery in patients with Cushing's Syndrome

Background Cushing’s Syndrome (CS) is associated with excess and premature cardiovascular disease. Endothelial dysfunction is the initiating event in the development of atherosclerosis. Endothelial function is assessed by flow-mediated dilatation (FMD) of brachial artery. The aim of this study was to assess FMD in patients with CS. Methods We prospectively evaluated 22 patients with CS (12 women, 10 men; aged 42 ± 11 years, serum cortisol 28.2 ± 14 μg/dl, 24-h urinary free cortisol (UFC) 269 ± 92 μg/day), and 23 control subjects (13 women, 10 men; aged 43 ± 10 years, serum cortisol 14 ± 4 μg/dl, 24 h cortisol 60 ± 22 μg/day). Endothelial function, measured as FMD of the brachial artery using ultrasound, was calculated in two groups. Endothelial function was evaluated by assessing 1-min postischemic FMD of the brachial artery. Results FMD was lower in patients with CS than that in those without (11.7 ± 4.8% vs. 15.8 ± 3.2%, P = 0.0001, respectively). There was no significant difference between two groups regarding baseline diameter of brachial artery. But, hyperemia diameter was lower in patients with CS than without CS (3.6 ± 0.22 mm vs. 3.9 ± 0.19 mm, P = 0.04, respectively) Conclusion Endothelium-dependent FMD may impair in patients with CS compared to controls. Measurement of endothelial function may identify high-risk individuals early and therapy to reduce or retard endothelial dysfunction in patients with CS may lead to decreased cardiovascular morbidity and mortality.     

Lubiprostone: a new drug for the treatment of chronic idiopathic constipation

Lubiprostone offers an additional alternative for patients with chronic idiopathic constipation. Lubiprostone is more efficacious than placebo in the treatment of chronic idiopathic constipation. In placebo-controlled clinical trials, lubiprostone therapy was generally well tolerated and was not associated with severe adverse effects; however, the high incidence of nausea may be problematic for some patients. The nausea may be alleviated or minimized by administering the dose with food, and some patients may require a dosage reduction to 24 mug once daily. The key limitations of the placebo-controlled clinical trials include the absence of information regarding the duration of the constipation and previous types of therapies that had been used to treat the constipation and the absence of an active control group. Comparative studies with other therapies (eg, saline laxatives, polyethylene glycol) used for constipation are necessary to determine the clinical and economic value of this agent relative to other forms of therapy.