Paradigm shift in hydrocephalus research in legacy of Dandy’s pioneering work: rationale for third ventriculostomy in communicating hydrocephalus

Objective This study aims to question the generally accepted cerebrospinal fluid (CSF) bulk flow theory suggesting that the CSF is exclusively absorbed by the arachnoid villi and that the cause of hydrocephalus is a CSF absorption deficit. In addition, this study aims to briefly describe the new hydrodynamic concept of hydrocephalus and the rationale for endoscopic third ventriculostomy (ETV) in communicating hydrocephalus. Critique The bulk flow theory has proven incapable of explaining the pivotal mechanisms behind communicating hydrocephalus. Thus, the theory is unable to explain why the ventricles enlarge, why the CSF pressure remains normal and why some patients improve after ETV. Hydrodynamic concept of hydrocephalus Communicating hydrocephalus is caused by decreased intracranial compliance increasing the systolic pressure transmission into the brain parenchyma. The increased systolic pressure in the brain distends the brain towards the skull and simultaneously compresses the periventricular region of the brain against the ventricles. The final result is the predominant enlargement of the ventricles and narrowing of the subarachnoid space. The ETV reduces the increased systolic pressure in the brain simply by venting ventricular CSF through the stoma. The patent aqueduct in communicating hydrocephalus is too narrow to vent the CSF sufficiently.     

Pelvic Ring Fractures: Utility of Clinical Examination in Patients with Impaired Consciousness or Tracheal Intubation

Abstract Objective: To define the diagnostic accuracy of clinical examination in patients with impaired consciousness or endotracheal intubation to detect pelvic ring fractures and to identify those with severe bleeding. Methods: Included in this prospective data collection with retrolective data analysis were a consecutive series of blunt trauma victims with either a Glasgow Coma Scale ≤ 13 or tracheal intubation. Clinical examination comprised testing for stability of the iliac wings. Results: From 784 subjects (injury severity score 23.3 ± 17.4) 93 patients (11.9%) were found to have a pelvic ring fracture. Clinical instability of the pelvic ring was found in 42 patients. There was only one false positive. Fifty-two fractures could not be identified by clinical examination, including nine fractures (17%) that required surgical fracture stabilization (sensitivity of clinical examination 44.1%). Seventeen fractures (18.3%) were associated with a blood loss larger than 20% of circulating blood volume. Sixteen of those were identified by clinical instability of the pelvic ring (sensitivity 94.1%, specificity 97.0%, positive predictive value 38.1%, negative predictive value 99.9%). Conclusions: Clinical examination for stability of the pelvis in this selected group of patients missed a significant number of pelvic ring fractures including fractures that require surgical stabilization. The finding of a clinically unstable identifies most of the patients with the pelvic ring fracture being a major source of bleeding. A stable pelvis makes pelvic ring fracture as being the source of bleeding quite unlikely.     

脊柱复合性损伤的救治风险与早期治疗

目的评估脊柱复合性损伤的特点和救治风险,探讨风险控制与最佳治疗的方法。方法采用AIS、ISS、TRISS及APACHEⅡ等评分方法对273例脊柱复合性损伤患者进行定量评价与救治分类,并依据伤后的损伤分级、参数评定及计量评分等指标进行量化分析和统计处理。结果颈椎合并伤115例,胸椎合并伤141例,胸腰椎合并伤294例,腰骶椎合并伤181例;患者的救治风险和脊椎伤的治疗选择或手术时机与其合并伤的解剖伤势及由此所构成的整体伤情密切相关(P<0.01或<0.05);高风险性伤员往往综合伤势严重,生存概率(Ps)趋低,并发症和死亡率高(P<0.01或<0.05)。结论脊柱脊髓损伤常合并有严重的多发伤,高危伤情不仅可增加其救治风险和脊柱伤的处理难度,且还易于丧失手术最佳时机。分类救治对伤员的风险控制和脊柱伤的专科治疗是有益的。     

Disruption of cellular energy balance by suramin in intact human prostatic carcinoma cells, a likely antiproliferative mechanism.

The antiparasitic drug, suramin, has antiproliferative effects in human carcinoma cells. It has been suggested that this occurs through blockade of growth factor-receptor interactions. Three types of evidence that suramin rapidly inhibits cellular respiration or disrupts cellular energy balance in intact cells of the human prostate carcinoma cell line, DU145, are presented. Beginning at approximately 10(-4) M, suramin rapidly causes dose-dependent inhibition of tetrazolium conversion by mitochondrial dehydrogenases in intact cells, demonstrating an inhibition of respiration. This effect is reversed by exchange with suramin-free media but not by pretreatment with serum, epidermal growth factor, insulin-like growth factor I, acidic and basic fibroblast growth factors, or calcium. Rhodamine 123 (10 micrograms/ml) uptake by mitochondria in intact DU145 cells is inhibited in the presence of 10(-3) M suramin. Treatment with 10(-4)-10(-3) M suramin causes the loss of rhodamine 123 from cells with mitochondria prestained with rhodamine 123, indicating that suramin is acting as an ionophore or respiratory poison. Also shown by electron microscopy are progressive toxic changes in mitochondria of DU145 cells within 1 h after treatment with 10(-4) M suramin. These data indicate that in intact DU145 cells 10(-4) M suramin rapidly disrupts cellular energy balance or respiration as seen by three studies of mitochondrial state. Disruption of energy balance or respiration represents a likely antiproliferative mechanism, as is thought to be a primary mechanism for the action of suramin in parasitic diseases. This proposed mechanism of action for suramin can explain the most prominent observed clinical toxicities of nephrotoxicity, adrenal toxicity, coagulopathy, and demyelinating neuropathy.     

Classification tree analysis of second neoplasms in survivors of childhood cancer

Background  

Reports on childhood cancer survivors estimated cumulative probability of developing secondary neoplasms vary from 3,3% to 25% at 25 years from diagnosis, and the risk of developing another cancer to several times greater than in the general population.     

Sleep and recovery in physicians on night call: a longitudinal field study

Background  

It is well known that physicians' night-call duty may cause impaired performance and adverse effects on subjective health, but there is limited knowledge about effects on sleep duration and recovery time. In recent years occupational stress and impaired well-being among anaesthesiologists have been frequently reported for in the scientific literature. Given their main focus on handling patients with life-threatening conditions, when on call, one might expect sleep and recovery to be negatively affected by work, especially in this specialist group. The aim of the present study was to examine whether a 16-hour night-call schedule allowed for sufficient recovery in anaesthesiologists compared with other physician specialists handling less life-threatening conditions, when on call.     

Associations between street connectivity and active transportation

Background  

Past studies of associations between measures of the built environment, particularly street connectivity, and active transportation (AT) or leisure walking/bicycling have largely failed to account for spatial autocorrelation of connectivity variables and have seldom examined both the propensity for AT and its duration in a coherent fashion. Such efforts could improve our understanding of the spatial and behavioral aspects of AT. We analyzed spatially identified data from Los Angeles and San Diego Counties collected as part of the 2001 California Health Interview Survey.