Repair of chronic tympanic membrane perforations with long-term epidermal growth factor

Chronic tympanic membrane (TM) perforation is a common problem worldwide. Recent reports have shown epidermal growth factor (EGF) to stimulate healing in approximately 80% of chronic TM perforations in chinchillas when applied in three doses over 1 week. The objective of this controlled study is to evaluate the efficacy of long-term EGF in the closure of TM perforations. Chronic chinchilla TM perforations were treated with EGF for up to 6 weeks. One hundred percent (17 of 17) of treatment group perforations completely healed. However, two new findings with this long dosing scheme were reperforation on long-term follow-up and three TMs with cholesteatomas. It is likely that reperforation was due to a progressive thinning seen with prolonged EGF application. Long-term EGF use is not recommended for the treatment of TM perforations because of possible wound healing impairment and possible cholesteatoma induction.     

Post-transplant focal segmental glomerulosclerosis refractory to plasmapheresis and rituximab therapy

Sir, Primary focal segmental glomerulosclerosis (FSGS) recurs in20 to 50% of kidney transplants [1]. Recently, there have beenreports demonstrating the successful use of rituximab for recurrentpost-transplant FSGS [2–4]. We report a case of recurrentFSGS that was refractory to both     

Complications and catheter survival with prolonged embedding of peritoneal dialysis catheters.

BACKGROUND: Our centre uses a modification of the Moncrief technique of embedding peritoneal dialysis (PD) catheters. We undertook this study to test the hypothesis that catheter survival on PD is a function of the time a catheter is left embedded prior to use. METHODS: Data were retrospectively abstracted from review of patient records of those who received a first PD catheter over a 5-year period. Patients were divided into tertiles based on the number of days between insertion of the catheter and exteriorization to create three equal groups representing early (group 1, 11-47 days), mid (group 2, 48-133 days) and late (group 3, 134-2041 days) exteriorization strategies. RESULTS: 435 embedded PD catheters were inserted, 349 were exteriorized and total observation period was 5624 patient-months. Time to catheter loss was shortest in group 1 and longest in group 2 (P = 0.04). The overall rate of primary catheter failure was 6% and was significantly different in the three groups (6.9% in group 1, 1.7% in group 2 and 9.4% in group 3, P = 0.04). The time to first episode of peritonitis was longest in group 3 and shortest in group 1 (group 1 versus group 3, P = 0.009; group 2 versus group 3, P = 0.03). Adjusted peritonitis rates, however, were not different between the three groups. CONCLUSIONS: Mechanical complications and catheter loss are associated with the length of time a catheter is embedded. We recommend insertion 6 weeks to 5 months ahead of the need for PD to maximize catheter survival.     

AN ANALYSIS OF VISUAL PERFORMANCE WITH SOFT CONTACT LENS AND SPECTACLE CORRECTION

This study compares, under controlled conditions and by rigorous statistical analysis, the contrast sensitivity function (CSF) measured with soft-lens and spectacle correction, attempting to resolve the conflicting reports in the literature. Ten non-astigmatic ametropic subjects had the CSF measured at eight spatial frequencies with the two types of visual correction. Analysis of variance revealed statistically significant effects for subjects, stimuli and type of visual correction, statistically superior performance being obtained with soft lenses. However, the actual difference in the CSF for the two forms of correction was small (0.14 log units) and not clinically significant. Comparison of the average CSF for the three highest and lowest spatial frequencies tested revealed a significant advantage in using higher spatial frequencies in the determination of statistical differences in the CSF obtained with different types of visual correction.     

Collateral Sprouting of Central Noradrenergic Neurons during Aging: Histochemical and Neurochemical Studies in Intraocular Triple Transplants

The sprouting capacity of aged noradrenergic neurons of the brain-stem nucleus locus coeruleus (LC) was examined using intraocular transplants of fetal tissues. Fetal hippocampal tissue (E18) and LC tissue (E15) were transplanted together as a double transplant into the anterior chamber of the eye of young adult Fischer 344 rats. The double transplants were allowed to mature for 14–18 months, after which an additional fetal hippocampal transplant was placed next to the LC graft. The triple transplants were monitored for overall growth and vascularization for an additional 2–6 months. Immunohistochemical examinations showed that both young (2–6 months old) and aged (16–24 months old) hippocampal cografts contained a plexus of thin varicose tyrosine hydroxylase (TH)-immunoreactive fibers extending throughout the grafted hippocampal tissues. However, the aged hippocampal grafts contained a denser uniform plexus of TH-positive fibers compared to the young transplants. Immunohistochemistry with synapsin antibodies demonstrated that both the young and the aged hippocampal transplants contained much higher densities of synaptic elements than the LC grafts.In vivoelectrochemical measurements of potassium-evoked overflow of norepinephrine (NE) in the grafts showed that similar amounts of NE overflow were detected in both the young and the aged hippocampal grafts. HPLC–EC measurements of NE levels in the grafts revealed that there were similar amounts of NE in the young and the aged grafts, and the grafts did not contain serotonin or dopamine. In summary, the findings of the present study show that aged LC neurons are capable of undergoing collateral sprouting producing a functional NE neuronal system when introduced to an appropriate young target.