eTEP inferior access with tailored retromuscular dissection for small to mid-sized umbilical hernia repair with or without inguinal hernia: early experience

Hernia - The minimally invasive surgical repair of combined inguinal and ventral hernias often requires shifting from one approach or plane to another. The traditional enhanced-view totally...     

Motor and non-motor sequence learning in children and adolescents with cerebellar damage.

Cerebellar involvement in motor and non-motor sequence learning was examined with serial reaction time tasks (SRT). Our sample consisted of 8 children and adolescents who had undergone surgical removal of a benign posterior fossa tumor (PFT) during childhood. None of them had undergone chemotherapy or cranial radiation therapy (CRT). Ages ranged from 1-11 years at surgery and 9-17 years at testing. The children were tested not earlier than 2.5 years after surgery (M = 5.9 years), enabling brain plasticity and recovery of functions. Their performance was compared with a matched control sample. The PFT group was not impaired in the implicit learning of sequences, as reflected in their performance in blocks with a repeated sequence, both before and after a random block. However, in the perceptual task, their performance deteriorated more than that of the control group when a random block was introduced, suggesting that it was more difficult for the patients to respond flexibly or change their response set when encountering changing task demands. These results are in line with another study by our group on task switching with the same patients.     

The occurrence of obstructive vs absorptive hydrocephalus in newborns and infants: relevance to treatment choices

Background and objective The classification of hydrocephalus in newborns and in infants is different from the classification in adulthood. This difference exists due to disparity in the source pathologies that produce the hydrocephalus, and the practical distinctions in prognosis and treatment choices. The objective of this paper is to present the spectrum of obstructive-communicating hydrocephalus, which is more complex in the pediatric group, and to propose the relevance of this particular classification to treatment options. Materials and methods The authors categorized infants with active hydrocephalus at time of presentation into the following four groups along the spectrum of communicating vs obstructive HCP. Group 1: patients with a purely absorptive (communicating) HCP. In these patients, tetraventricular dilatation is usually observed with occasional extraaxial fluid accumulation. An extracranial CSF diversion (shunt) is the treatment of choice. Group 2: patients with an obstructive component together with a persistent absorptive component. In these patients, a technically successful endoscopic procedure will not prevent progression of clinical symptoms of HCP. An extracranial CSF diversion (shunt) should be the treatment of choice even though some of these patients are currently treated by endoscopy. Group 3: patients with an obstructive component together with a temporary absorptive component. In these patients, a technically successful ETV should be followed by temporary CSF drainage [via LP, continuous spinal drainage (CLD), or ventriculostomy] with or without supplemental medical treatment (i.e., Diamox) for several days. Such temporary drainage may decrease failure rate in this subgroup. Group 4: patients with a purely obstructive HCP. In these patients, an endoscopic procedure (ETV) is the treatment of choice. According to this spectrum classification, the authors classify different entities with representative cases and discuss relevancy to treatment options and prognosis. Results The data suggest that obstructive hydrocephalus in the very young population may be rather a combination of obstructive and absorptive problem. The outcome of the patient depends mainly not only on the basic pathology causing the hydrocephalus but also on the treatment that is chosen and its complications. While bleeding and infection represent the major causes for communicating hydrocephalus, patients with complex pathologies of congenital type and intra- or interventricular obstructions may reflect obstructive hydrocephalus. Treatment of these patients may be successful by shuntless procedures if the absorptive problem is not the major component. In transient absorptive hydrocephalus, temporary measures were effective in many cases leading to successful procedures of ETV and/or posterior-fossa decompression in selected cases. Conclusions Shuntless procedures are the dream of a pediatric neurosurgeon provided it solves the problem and does not imply unacceptable risk. However, the benefit has to be evaluated years after the procedure is performed, as only prospective multicenter studies will truly show which procedure may have the best overall results in the developing child. Until such studies are available, understanding the basic pathology or the combination of pathologies leading to hydrocephalus in a given child may open the window of opportunities for other than shunt surgery in many hydrocephalic children with major obstructive component.     

Bilateral Todd''s Paralysis After Focal Seizures

Transient postictal hemiparesis or monoparesis is not uncommon after partial (focal) seizures. We report 2 patients who complained of severe bilateral limb weakness after generalized tonic-clonic seizures (GTCS) beginning focally. Bilateral Todd's paralysis was verified and documented in both patients. EEG and clinical evidence indicate the supplementary motor cortex as the most likely source of the seizures in both cases.     

Telemedicine and international disaster response. Medical consultation to Armenia and Russia via a Telemedicine Spacebridge

The Telemedicine Spacebridge, a satellite-mediated, audio-video-fax link between four United States and two Armenian and Russian medical centers, permitted remote American consultants to assist Armenian and Russian physicians in the management of medical problems following the December 1988 earthquake in Armenia and the June 1989 gas explosion near Ufa. Methods: During 12 weeks of operations, 247 Armenian and Russian and 175 American medical professionals participated in 34 half-day clinical conferences. A total of 209 patients were discussed, requiring expertise in 20 specialty areas. Results: Telemedicine consultations resulted in altered diagnoses for 54, new diagnostic studies for 70, altered diagnostic processes for 47, and modified treatment plans for 47 of 185 Armenian patients presented. Simultaneous participation of several US medical centers was judged beneficial; quality of data transmission was judged excellent. Conclusion: These results suggest that interactive consultation by remote specialists can provide valuable assistance to on-site physicians and favorably influence clinical decisions in the aftermath of major disasters.     

Selective degradation of cyclin B1 mRNA in rat oocytes by RNA interference (RNAi)

Cyclic adenosine monophosphate (cAMP) keeps oocytes in meiotic arrest, thereby preventing activation of the key regulators of meiosis, p34cdc2/cyclin B1, (known as maturation-promoting factor (MPF)) and Erk 1 and 2, members of the mitogen-activated protein kinase (MAPK) family. The activity of MAPK in oocytes is upregulated by Mos. We previously demonstrated that Mos translation in rat oocytes is negatively regulated by a PKA-mediated cAMP action, which inhibits c-mos mRNA polyadenylation and is associated with the suppression of p34 cdc2 kinase. The goal of the present study was to provide definitive evidence that Mos translation is subjected to MPF regulation. In order to inhibit MPF activity, we employed the double-stranded (ds) RNA interference (RNAi) of gene expression. We demonstrated that the introduction of cyclin B1 dsRNA into rat oocytes selectively depleted the corresponding mRNA, further ablating its protein product. These oocytes, which exhibit low MPF activity, failed to elongate the c-mos mRNA poly(A) tail, did not accumulate Mos and were unable to activate MAPK. We conclude that an active MPF in rat oocytes is necessary for c-mos mRNA polyadenylation and Mos translation.     

Diurnal Fluctuations in HPA and Neuropeptide Y-ergic Systems Underlie Differences in Vulnerability to Traumatic Stress Responses at Different Zeitgeber Times

The hypothalamic–pituitary–adrenal (HPA) axis displays a characteristic circadian pattern of corticosterone release, with higher levels at the onset of the active phase and lower levels at the onset of the inactive phase. As corticosterone levels modify the response to stress and influence the susceptibility to and/or severity of stress-related sequelae, we examined the effects of an acute psychological trauma applied at different zeitgeber times (ZTs) on behavioral stress responses. Rats were exposed to stress either at the onset of the inactive-(light) phase (ZT=0) or at the onset of the active-(dark) phase (ZT=12). Their behavior in the elevated plus-maze and acoustic startle response paradigms were assessed 7 days post exposure for retrospective classification into behavioral response groups. Serum corticosterone levels and the dexamethasone suppression test were used to assess the stress response and feedback inhibition of the HPA axis. Immunoreactivity for neuropeptide Y (NPY) and NPY-Y1 receptor (Y1R) in the paraventricular (PVN) and arcuate (ARC) hypothalamic nuclei, hippocampus, and basolateral amygdala were measured. The behavioral effects of NPY/Y1R antagonist microinfused into the PVN 30 min before stress exposure during the inactive or active phase, respectively, were evaluated. PVN immunoreactivity for NPY and Y1R was measured 1 day after the behavioral tests. The time of day of the traumatic exposure markedly affected the pattern of the behavioral stress response and the prevalence of rats showing an extreme behavioral response. Rats exposed to the stressor at the onset of their inactive phase displayed a more traumatic behavioral response, faster post-exposure corticosterone decay, and a more pronounced stress-induced decline in NPY and Y1R expression in the PVN and arcuate hypothalamic nuclei. Blocking PVN Y1R before stress applied in the active phase, or administering NPY to the PVN before stress applied in the inactive phase, had a resounding behavioral effect. The time at which stress occurred significantly affected the behavioral stress response. Diurnal variations in HPA and NPY/Y1R significantly affect the behavioral response, conferring more resilience at the onset of the active phase and more vulnerability at the onset of the inactive phase, implying that NPY has a significant role in conferring resilience to stress-related psychopathology.