Early and late visual prognosis in solar retinopathy

Background: Solar retinopathy was observed in a total of 86 eyes of 58 patients following the solar eclipse over Turkey in April 1976. The visual prognosis and the presence of late complications were evaluated at the early and late periods. Methods: Of the 58 patients, 34 (51 eyes) presented during the first week and came for follow-up examination in the succeeding week, also after 1, 3, 12 and 18 months. After that they were examined at yearly intervals (mean 4.2 years). Twenty-four patients (35 eyes) presented during the period between 1 and 11 years post-eclipse and were followed up for a mean period of 3.4 years. After a period of 15 years, all of the patients were invited for re-examination and nine patients (14 eyes) attended. Results: The improvement in visual acuity was observed to have taken place mostly during the first 2 weeks to 1 month after the eclipse. Further improvement in visual acuity was not observed in any of the eyes after the 18-month examination. The improvement in visual acuity was more prominent and earlier in the eyes that had visual acuity of 0.2 or better initially. Only the eyes with initial visual acuity equal to or better than 0.4 had a chance to improve their acuity to 10/10. Having observed the 51 eyes for mean period of 4.2 years and the 35 eyes for 3.4 years, no change in visual acuity was observed. Among the total of 86 eyes, 9 were found to have pseudolamellar macular holes. Conclusion: Correlation was found between initial visual acuity and the funduscopic appearance after the 2nd week. Fluorescein angiography was not found to be a conclusive test in solar retinopathy. No late complications were observed.     

Apoptosis in brain biopsies of subacute sclerosing panencephalitis patients

Subacute sclerosing panencephalitis (SSPE) is associated with inflammatory infiltration, neuronal loss, and demyelination. The pathogenesis of these changes is unclear. We examined DNA fragmentation and Bcl-2 expression in brain biopsies of nineteen SSPE patients to investigate the role of apoptosis in tissue damage. DNA fragmentation was present in oligodendroglia, and, in tissues with neuronal loss, in neurons. Reactive astrocytes had no DNA fragmentation, but strong Bcl-2 expression. These results suggest apoptosis as one of the mechanisms for oligodendroglial and neuronal death in SSPE.     

Characterization of melanocortin receptor ligands on cloned brain melanocortin receptors and on grooming behavior in the rat.

Since the melanocortin MC3 and melanocortin MC4 receptors are the main melanocortin receptor subtypes expressed in rat brain, we characterized the activity and affinity of nine melanocortin receptor ligands using these receptors in vitro, as well as their activity in a well-defined melanocortin-induced behavior in the rat: grooming behavior. We report here that [D-Tyr4]melanotan-II and RMI-2001 (Ac-cyclo-[Cys4, Gly5, D-Phe7, Cys10]alpha-MSH-NH2) have significantly higher affinity and potency on the rat melanocortin MC4 receptor as compared to the rat melanocortin MC3 receptor. Nle-gamma-MSH (melanocyte-stimulating hormone) was the only ligand with higher affinity and potency on the rat melanocortin MC3 receptor. The potency order of melanocortin MC4 receptor agonists, but not that of melanocortin MC3 receptor agonists, fitted with the potency of these ligands to stimulate grooming behavior, when administered intracerebroventricularly. SHU9119 (Ac-cyclo-[Nle4, Asp5, D-Nal(2)7, Lys10]alpha-MSH-(4-10)-NH2) and RMI-2005 (Ac-cyclo-[Cys4, Gly5, D-Na](2)7, Nal(2)9, Cys10]alpha-MSH-(4-10)-NH2) were able to inhibit alpha-MSH-induced melanocortin receptor activity in vitro, as well as alpha-MSH-induced grooming behavior. Melanotan-II, [Nle4-D-Phe7]alpha-MSH and RMI-2001 were also effective in inducing grooming behavior when administered intravenously. In the absence of purely selective melanocortin MC(3/4) receptor ligands, we demonstrated that careful comparison of ligand potencies in vitro with ligand potencies in vivo, could identify which melanocortin receptor subtype mediated alpha-MSH-induced grooming behavior. Furthermore, blockade of novelty-induced grooming behavior by SHU9119 demonstrated that this physiological stress response is mediated via activation of the melanocortin system.     

Serum amino acid levels after permanent middle cerebral artery occlusion in the rat

BACKGROUND AND PURPOSE: High levels of glutamate in plasma and cerebrospinal fluid (CSF) have been demonstrated in patients with acute ischemic stroke. Whereas this glutamate increase in CSF is only evidenced during the first 6 h in stable ischemic stroke, it is sustained for 24 h in progressing stroke. The aim of this investigation was to study the evolution of serum glutamate levels after stroke in a rat model of permanent cerebral artery occlusion. METHODS: Glutamate, glycine, aspartate, taurine and tryptophan were measured by high-performance liquid chromatography from serum samples taken before and at different times after permanent middle cerebral artery occlusion (MCAO) and from sham-operated rats. RESULTS: After MCAO, a 3-fold increase in glutamate and a 2-fold increase in glycine and aspartate were observed in rat serum. The onset of this amino acid increase began 4-6 h after ischemic induction, reached peak values at 8-24 h and returned to preischemic values by 48-72 h. Serum concentrations of taurine and tryptophan were not modified after MCAO. Sham-operated rats did not exhibit changes of basal amino acid concentrations in serum. CONCLUSIONS: The serum excitatory amino acid profile in this experimental model confirms that the early detection of increased concentrations of glutamate and glycine at systemic circulation observed in patients with acute stroke is a consequence of the cerebral ischemic process.     

The effect of leptin on luteinizing hormone release is exerted in the zona incerta and mediated by melanin-concentrating hormone

The adipose hormone, leptin, not only restrains appetite, but also influences energy expenditure. One such influence is to promote sexual maturation and fertility. The neuromodulatory circuits that mediate this effect are not well known but the present study suggests that one mediator could be melanin-concentrating hormone (MCH). We show that the long-form receptor (Ob-Rb) is expressed in the zona incerta of the rat and that administration of leptin (both 0.5 microg and 1.0 microg/side) into this area of ovariectomized, oestrogen-primed rats stimulated the release of luteinizing hormone (LH) within 1 h, the effect enduring for a further 1 h. Injections of leptin into the arcuate nucleus induced a smaller, transient rise in LH while injections into the paraventricular and ventromedial nuclei were without effect. MCH neurones are present in the zona incerta and administration of this hormone into the medial preoptic area (mPOA) stimulates LH release, therefore we investigated the possibility that MCH might mediate this effect of leptin. An injection of MCH antiserum into mPOA prevented the rise in LH normally induced by leptin injected into the zona incerta. In addition, melanocortin receptor antagonists ([D-Arg8]ACTH(4-10) and [Ala6]ACTH(4-10)), previously shown to inhibit the stimulatory effect of MCH on LH release, also inhibited the effect of leptin. We propose that one route by which leptin may promote reproductive activity is by enhancing MCH release from fibres within the mPOA. Speculative mechanisms for the action of MCH include the following possibilities: MCH may be acting on the specific MCH receptor which in turn interacts with a melanocortin or melanocortin-like receptor; MCH may bind directly to one of the melanocortin receptors; or melanocortin antagonists may interact with the MCH receptor.     

Effect of pediatric advanced life support course on pediatric residents' intubation success

Background: The Pediatric Advanced Life Support Program (PALS) course very important for teaching about intubation, resuscitation, shock, trauma, respiratory failure and rhythm disturbances. The aim of the present study was to evaluate the effect of the PALS course on pediatric residents' intubation success during their rotation, daytime and night‐time practice in the pediatric intensive care unit (PICU). Methods: The study was carried out from 1 March 2005 to 28 February 2007. The study period had two parts, in that the number of attempts and successful intubations performed by pediatric residents, and the pediatric intensivist successful intubation ratio were evaluated in two different periods: before the PALS course, 1 March 2005–28 February 2006, and after the PALS course, 5 March 2006–28 February 2007. The participating residents' pediatric levels (PL) were classed as PL‐1, PL‐2, PL‐3, PL‐4, and all had first experience in the PICU at the PL‐1 level. The PALS instructor was a pediatric emergency or intensive care doctor. We evaluated whether the PALS course influenced intubation success or not. Results: Sixteen residents participated in the study. The proportion of successful intubations was 110 (53.3%) and 104 (65.4%) attempts before and after the PALS course, respectively. The proportion of intubations done by intensivists decreased from 49.1% to 31.7% before and after PALS. The most frequently used endotracheal tube (ETT) internal diameter (ID) was 4.0 mm, and cuffed ETT was used 16% and 21% before and after the course, respectively. Appropriate placing of ETT tip occurred 70.4% and 82.2% of the time before and after the PALS course, respectively. Proportion of successful intubations by residents increased in all levels, except for PL‐1. The most important reason for unsuccessful attempts was inappropriate patient position. Only one patient could not be intubated, and laryngeal mask airway was used in that case. During intubation, complications were broken teeth in two patients before the course, and subglottic stenosis developed in only one patient due to cuffed ETT. Conclusion: Successful intubation is a life‐saving intervention during resuscitation, ETT revision for extubation or obstruction for extubation or obstruction during mechanical ventilation. This skill can be developed in the PALS course and by clinical study in PICU and pediatric emergency services. The PALS course must be given to pediatric residents especially within the first year. Also, cuffed ETT can be used for infants and children.     

A late complication of transobturator tape procedure: vaginocutaneous fistula formation with vaginal mesh erosion

Transobturator tape procedures are a common treatment modality in patients with stress urinary incontinence (SUI). Various complications have been reported related to this procedure. We present a rare case of vaginocutaneous fistula formation 5 years after transobturator tape surgery. A 56-year-old woman presented with complaints of increased vaginal discharge, difficulty in coitus, and serosanguineous discharge from the left groin 5 years after transobturator tape surgery for SUI. Pelvic examination revealed 2–3 cm of extruded mesh at the anterior vaginal wall. The vaginocutaneous fistula was detected at surgery. The suburethral tape was removed, and the fistula tract was excised and repaired primarily. Postoperative period was uneventful, and the patient was still continent 6 weeks postoperatively. With widespread use of mesh for treating SUI, we will likely see a variety of complications in the long term.     

Exposure to mild blast forces induces neuropathological effects,neurophysiological deficits and biochemical changes

Direct or indirect exposure to an explosion can induce traumatic brain injury (TBI) of various severity levels. Primary TBI from blast exposure is commonly characterized by internal injuries, such as vascular damage, neuronal injury, and contusion, without external injuries. Current animal models of blast-induced TBI (bTBI) have helped to understand the deleterious effects of moderate to severe blast forces. However, the neurological effects of mild blast forces remain poorly characterized. Here, we investigated the effects caused by mild blast forces combining neuropathological, histological, biochemical and neurophysiological analysis. For this purpose, we employed a rodent blast TBI model with blast forces below the level that causes macroscopic neuropathological changes. We found that mild blast forces induced neuroinflammation in cerebral cortex, striatum and hippocampus. Moreover, mild blast triggered microvascular damage and axonal injury. Furthermore, mild blast caused deficits in hippocampal short-term plasticity and synaptic excitability, but no impairments in long-term potentiation. Finally, mild blast exposure induced proteolytic cleavage of spectrin and the cyclin-dependent kinase 5 activator, p35 in hippocampus. Together, these findings show that mild blast forces can cause aberrant neurological changes that critically impact neuronal functions. These results are consistent with the idea that mild blast forces may induce subclinical pathophysiological changes that may contribute to neurological and psychiatric disorders.