Descending respiratory polysynaptic inputs to cervical and thoracic motoneurons diminish during early postnatal maturation in rat spinal cord

Isolated brainstem-spinal cord preparations were used to explore the coexistence of a direct and an indirect descending drive from the brainstem respiratory centre to cervical and thoracic respiratory motoneurons in the neonatal Sprague-Dawley rat. Polysynaptic spinal relay pathways from the respiratory centre were suppressed by selectively perfusing the cord with mephenesin (1 mM) or a solution enriched with Ca2+ and Mg2+. At birth, both direct and spinally relayed pathways are functional and contribute equally to the global descending respiratory drive. However, during the first postnatal week, significant maturational changes appear in the way the respiratory centre controls its target respiratory motoneurons in the cervical and thoracic spinal cord, with the direct respiratory drive becoming progressively predominant with maturation (from 50% to around 75% of the global descending command). The relative contributions of the monosynaptic and the polysynaptic spinal pathways may therefore have important implications for effective respiratory control during early postnatal development.     

Enhanced extrastriate visual response to bandpass spatial frequency filtered fearful faces: time course and topographic evoked-potentials mapping

We compared electrical brain responses to fearful vs. neutral facial expressions in healthy volunteers while they performed an orthogonal gender decision task. Face stimuli either had a broadband spatial-frequency content, or were filtered to create either low spatial-frequency (LSF) or high spatial-frequency (HSF) faces, always overlapped with their complementary SF content in upside-down orientation to preserve the total stimulus energy. We tested the hypothesis that the coarse LSF content of faces might be responsible for an early modulation of event-related potentials (ERPs) to fearful expressions. Consistent with previous findings, we show that broadband images of fearful faces, relative to neutral faces, elicit a higher global field power of approximately 130 ms poststimulus onset, corresponding to an increased P1 component over lateral occipital electrodes, with neural sources located within the extrastriate visual cortex. Bandpass filtering of faces strongly affected the latency and amplitude of ERPs, with a suppression of the normal N170 response for both LSF and HSF faces, irrespective of expression. Critically, we found that LSF information from fearful faces, unlike HSF information, produced a right-lateralized enhancement of the lateral occipital P1, without any change in the scalp topography, relative to unfiltered (broadband) fearful faces. These results demonstrate that an early P1 response to fear expression depends on a visual pathway preferentially tuned to coarse-magnocellular inputs, and can persist unchanged even when the N170 generators are disrupted by SF filtering.     

Retroperitoneal fibrosis secondary to spondylodiscitis after infection with Prevotella

We report a case of severe retroperitoneal fibrosis (RPF) secondary to lumbar spondylodiscitis caused by infection with Prevotella resolving after antibiotic therapy. Infection is an unusual cause of RPF, and infection in such cases with this anaerobic bacterium has never been described.     

Transumbilical approach for shunt insertion in the pediatric population: an improvement in cosmetic results

Objective In spite of the recent interest in endoscopic third ventriculostomy, ventriculoperitoneal (VP) shunt is still the gold standard in treating non-obstructive hydrocephalus in children. The peritoneal cavity remains the optimal site for cerebrospinal fluid (CSF) diversion. Shunt insertion and re-interventions carry a high risk of inaesthetic abdominal scars and long-term morbidity. We report a technique of transumbilical shunt insertion, which provides better cosmetic results and without many more complications. This approach has been performed for a long period in a wide variety of intra-abdominal conditions by pediatric surgeons.Methods Between March and October 2003, we inserted 12 VP shunts in children. For eight consecutively treated children the follow-up is more than 3 months. All the shunts were inserted through the umbilicus. These eight children are the subjects of this study. Indications for shunting were: communicating hydrocephalus (6 cases), subdural hematoma (1 case), and hygroma associated with an arachnoid cyst (1 case). The population consisted of 7 boys and 1 girl, ranging in age between 6 weeks and 47 months (mean age: 15 months), and their body weights varied between 2,110 g and 18,000 g (mean weight: 8,470 g). All children were examined twice a day for 3 days, and wounds were examined daily to check for the absence of sepsis or dehiscence. Clinical controls were performed 1 month after discharge. The operating surgeon was invited to comment on any difficulties encountered in making or closing this incision afterwards.Results The average length of clinical follow-up was 6 months (range 4–7 months). One infection of the VP shunt occurred. It was treated with external drainage and antibiotics. After 1 week, a second VP shunt was inserted using the same technique without particular difficulty and with a nice cosmetic result. Concerning the seven other children, the cosmetic results were optimal, with no puckered abdominal scars or wound dehiscence, and with no perioperative or long-term complications related to the umbilical approach.Conclusion At this early follow-up, umbilical incision for shunt insertion is a safe and easy technique. It provides an optimal cosmetic result, even in cases of re-intervention. This minimally invasive surgery does not require long specialized training. We have not shown an increase in complications associated with a learning curve. Longer follow-up is needed to evaluate the risk of infection.     

Prevalence of skin infections in sheltered homeless

In an attempt to determine the prevalence of various skin infections in the homeless population in Marseilles, France, we undertook a case control study. Cases were recruited among institutionalized homeless subjects during two snapshot investigations conducted in January 2002 and 2003 respectively. The control subjects were recruited from among those who presented at a clinic for pre-travel advice. We recruited 498 cases and 200 control subjects. Compared to control subjects, a significantly higher proportion of cases had skin diseases (38% versus 0.5%; p < 0.0001). Pruritus, body-lice infestation, scratching lesions, folliculitis, tinea pedis, scabies and impetigo (ecthyma) were strongly significantly associated with homelessness. The higher prevalence of skin infections in the homeless people mainly results from the body-louse infestation, scabies, bacterial super-infection of skin surfaces that have been breached by frequent scratching and tinea pedis due to poor foot hygiene.