重型颅脑损伤患者阶梯式减压策略下行去骨瓣减压术的应用效果及术中急性脑膨出的影响因素分析

摘要 目的：观察阶梯式减压策略下行去骨瓣减压术在重型颅脑损伤中的临床应用效果,并分析患者术中急性脑膨出的影响因素。方法：回顾性分析2020年1月~2021年8月期间我院收治的103例重型颅脑损伤患者的临床资料。根据手术方式的不同分为A组（常规去骨瓣减压术,n=50）和B组（阶梯式减压策略下行去骨瓣减压术,n=53）,比较两组手术相关指标、并发症发生率以及患者预后情况。此外,根据开颅术中是否出现急性脑膨出将患者分为膨出组（n=41）和未膨出组（n=62）,采用多因素Logistic回归分析重型颅脑损伤患者术中急性脑膨出的影响因素。结果：B组的迟发性颅内血肿、急性脑膨出发生率低于A组,术中出血量少于A组,手术时间短于A组（P<0.05）。B组的预后良好率高于A组（P<0.05）。单因素分析结果显示：重型颅脑损伤患者术中急性脑膨出与年龄、受伤至手术时间、合并迟发性外伤性颅内血肿（DTIH）、合并对侧颅骨骨折、入院后首次格拉斯哥昏迷指数（GCS）评分、合并外伤性弥漫性脑肿胀（PADBS）、高血压病史、术前体温、术前颅内压、血小板计数（PLT）、凝血酶原时间（PT）有关（P<0.05）。多因素Logistic回归分析结果显示：合并对侧颅骨骨折、合并DTIH、合并PADBS、受伤至手术时间＜3 h、入院后首次GCS评分＜6分、术前颅内压偏高、术前体温偏高是重型脑损伤患者术中急性脑膨出的危险因素（P＜0.05）,而阶梯式减压策略下行去骨瓣减压术则是其保护因素（P＜0.05）。结论：采用阶梯式减压策略下行去骨瓣减压术治疗重型颅脑损伤,可减少术中出血量,缩短手术时间,降低并发症发生率,改善患者的预后。重型颅脑损伤患者术中是否发生急性脑膨出受到合并对侧颅骨骨折、合并DTIH、合并PADBS、受伤至手术时间、入院后首次GCS评分、术前体温、术前颅内压等因素影响。     

Efficancy of decompressive craniectomy in treatment of severe brain injury at the Rijeka University Hospital Centre

Decompressive Craniectomy (DC) is a treatment option for severe brain injury (SBI). This method is applied when the growth of intracranial pressure (ICP) can no longer be controlled with conservative methods. DC belongs to class III "Guidelines"--"option" which has not clear clinical certainty. They do not correspond to "Standards" (class I) in treatment protocol for SBI, which is common in most neurotraumatological centers. We have analyzed retrospectively 95 patients with SBI who were admitted to the Clinical Hospital Centre Rijeka. All patients were managed based on a protocol of current Brain Trauma Foundations (BTF) Guidelines. 39 patients underwent DC while 34 patients underwent standard craniotomy. 22 patients did not undergo any surgical procedures. In each patient we analyzed ICP changes within the first 11 days and in that way we correlated them statistically with the initial Glasgow Coma Scale (GCS) and then with Glasgow Outcome Scale (GOS), after the end of the treatment. We particularly analyzed the outcome with reference to the time of the operation and the size of DC. The standard measurement of ICP shows statistical significance in recovery in the group without DC after 5 days of intensive treatment, when the pressure is stabilized between 20-25 mm Hg. The stabilization of ICP in the DC group is observed already after 3 days of intensive treatment. Furthermore, better functional recovery according to GOS, which is statistically significant, was observed in patients who underwent DC where the area of craniectomy was larger than 25 cm2, within the first 24 hours from the time of injury. The use of DC considerably reduces the need for CT check-ups. Increase in the number of encephalocele was noted, which is to be expected considering that dural decompression is used in DC procedure. The results of our study indicate that the utilization of DC is characterized with lower mortality and better functional recovery if it is applied at an early stage of treatment and if the size of DC is satisfactory.     

Frontoethmoidal encephalomeningocele: surgical correction by the Chula technique

This study reevaluates a surgical technique known as the Chula technique, previously reported in 1991 for correction of frontoethmoidal encephalomeningocele. From 1986 to 1999, 108 patients were operated on with this technique, which could remove the herniation mass, repair dural and bone defects, reconstruct the naso-orbital area, and restore aesthetic facial appearance in a single stage. Formal frontal craniotomy was not necessary. The result has been very satisfying in terms of safety, cure rate, and aesthetic outcome. Spontaneous improvement of lacrimal passage obstruction occurred in 85.2 percent of cases, and dacryocystorhinostomy was required in the rest. There was no mortality. Complications (e.g., wound infection, 6.5 percent; wire extrusion, 3.7 percent; meningitis, 2.8 percent; cerebrospinal fluid leakage, 2.8 percent; and postoperative increased intracranial pressure, 2.8 percent) were much less frequent than in other reports. With a mean follow-up period of 439 days (maximum, 12 years), there has been no recurrence.     

Posterior Fossa Decompression Combined with Resection of the Cerebellomedullary Fissure Membrane and Expansile Duraplasty: A Radical and Rational Surgical Treatment for Arnold–Chiari Type I Malformation

This study aims to introduce a new surgical procedure for the treatment of Arnold–Chiari type I malformation (ACM-1) and to compare its effectiveness with the techniques described in previous studies. We performed the following procedures: foramen magnum decompression combined with the removal of both the atlanto-occipital membrane, extended resection of the cerebellomedullary fissure arachnoid membrane, and artificial duraplasty to enlarge the membranic posterior fossa without resecting the cerebellar tonsils and syringosubarachnoid shunting. There were 21 ACM-1 patients: 12 cases had osteo-compression on the cerebellar hemisphere, 18 cases had thickened adhered fabric ring that stretched from arachnoid membrane to cerebellar hemisphere, and 15 cases with syringomyelia. The patients were followed up for 6 months to 3 years after the surgery. All patients showed a remarkable recovery of syringomyelia. There were no morbidity or death related to the surgery. Most of ACM-1 patients, the osteo- and membrane compression on cerebellar hemisphere and tonsil were observed during the operation. Therefore, decompression of foramen magnum and posterior craniocervical combined with the removal of cerebellomedullary fissure arachnoid membrane and placement of an artificial dural graft should be considered as a comprehensive option of minimally invasive surgery and rational and radical treatment of ACM-1. Our experience showed that, by using our procedure, shunting becomes no longer necessary in the treatment of ACM-1-associated syringomyelia.     

Temporo-Spectral Imaging of Intrinsic Optical Signals during Hypoxia-Induced Spreading Depression-Like Depolarization

Spreading depression (SD) is characterized by a sustained near-complete depolarization of neurons, a massive depolarization of glia, and a negative deflection of the extracellular DC potential. These electrophysiological signs are accompanied by an intrinsic optical signal (IOS) which arises from changes in light scattering and absorption. Even though the underlying mechanisms are unclear, the IOS serves as non-invasive tool to define the spatiotemporal dynamics of SD in brain slices. Usually the tissue is illuminated by white light, and light reflectance or transmittance is monitored. Using a polychromatic, fast-switchable light source we now performed temporo-spectral recordings of the IOS associated with hypoxia-induced SD-like depolarization (HSD) in rat hippocampal slices kept in an interface recording chamber. Recording full illumination spectra (320-680 nm) yielded distinct reflectance profiles for the different phases of HSD. Early during hypoxia tissue reflectance decreased within almost the entire spectrum due to cell swelling. HSD was accompanied by a reversible reflectance increase being most pronounced at 400 nm and 460 nm. At 440 nm massive porphyrin absorption (Soret band) was detected. Hypotonic solutions, Ca(2+)-withdrawal and glial poisoning intensified the reflectance increase during HSD, whereas hypertonic solutions dampened it. Replacement of Cl(-) inverted the reflectance increase. Inducing HSD by cyanide distorted the IOS and reflectance at 340-400 nm increased irreversibly. The pronounced changes at short wavelengths (380 nm, 460 nm) and their cyanide sensitivity suggest that block of mitochondrial metabolism contributes to the IOS during HSD. For stable and reliable IOS recordings during HSD wavelengths of 460-560 nm are recommended.     

Neuronal and Astroglial Correlates Underlying Spatiotemporal Intrinsic Optical Signal in the Rat Hippocampal Slice

Widely used for mapping afferent activated brain areas in vivo, the label-free intrinsic optical signal (IOS) is mainly ascribed to blood volume changes subsequent to glial glutamate uptake. By contrast, IOS imaged in vitro is generally attributed to neuronal and glial cell swelling, however the relative contribution of different cell types and molecular players remained largely unknown. We characterized IOS to Schaffer collateral stimulation in the rat hippocampal slice using a 464-element photodiode-array device that enables IOS monitoring at 0.6 ms time-resolution in combination with simultaneous field potential recordings. We used brief half-maximal stimuli by applying a medium intensity 50 Volt-stimulus train within 50 ms (20 Hz). IOS was primarily observed in the str. pyramidale and proximal region of the str. radiatum of the hippocampus. It was eliminated by tetrodotoxin blockade of voltage-gated Na⁺ channels and was significantly enhanced by suppressing inhibitory signaling with gamma-aminobutyric acid(A) receptor antagonist picrotoxin. We found that IOS was predominantly initiated by postsynaptic Glu receptor activation and progressed by the activation of astroglial Glu transporters and Mg²⁺-independent astroglial N-methyl-D-aspartate receptors. Under control conditions, role for neuronal K⁺/Cl⁻ cotransporter KCC2, but not for glial Na⁺/K⁺/Cl⁻ cotransporter NKCC1 was observed. Slight enhancement and inhibition of IOS through non-specific Cl⁻ and volume-regulated anion channels, respectively, were also depicted. High-frequency IOS imaging, evoked by brief afferent stimulation in brain slices provide a new paradigm for studying mechanisms underlying IOS genesis. Major players disclosed this way imply that spatiotemporal IOS reflects glutamatergic neuronal activation and astroglial response, as observed within the hippocampus. Our model may help to better interpret in vivo IOS and support diagnosis in the future.     

Real‐time augmented reality for delineation of surgical margins during neurosurgery using autofluorescence lifetime contrast

Current clinical brain imaging techniques used for surgical planning of tumor resection lack intraoperative and real‐time feedback; hence surgeons ultimately rely on subjective evaluation to identify tumor areas and margins. We report a fluorescence lifetime imaging (FLIm) instrument (excitation: 355 nm; emission spectral bands: 390/40 nm, 470/28 nm, 542/50 nm and 629/53 nm) that integrates with surgical microscopes to provide real‐time intraoperative augmentation of the surgical field of view with fluorescent derived parameters encoding diagnostic information. We show the functionality and safety features of this instrument during neurosurgical procedures in patients undergoing craniotomy for the resection of brain tumors and/or tissue with radiation damage. We demonstrate in three case studies the ability of this instrument to resolve distinct tissue types and pathology including cortex, white matter, tumor and radiation‐induced necrosis. In particular, two patients with effects of radiation‐induced necrosis exhibited longer fluorescence lifetimes and increased optical redox ratio on the necrotic tissue with respect to non‐affected cortex, and an oligodendroglioma resected from a third patient reported shorter fluorescence lifetime and a decrease in optical redox ratio than the surrounding white matter. These results encourage the use of FLIm as a label‐free and non‐invasive intraoperative tool for neurosurgical guidance.     

Small artery anastomosis, using a cuff of dura mater and a tissue adhesive.

A new and simple technique for the anastomosis of small arteries, using a lyophilized dural cuff and a tissue adhesive, is presented. The feasibility of this new technique was demonstrated on 26 carotid arteries in rats. Possible indications for it are noted.     

Neurobiology of posttraumatic stress disorder

Recent advances on the neurobiology of posttraumatic stress disorder include: the utilization of functional brain imaging; the incorporation of cross-system research including neuroendocrine (hypothalamic-pituitary-adrenal and hypothalamic-pituitary-thyroid axes), neurochemical (corticotropin-releasing factor, norepinephrine, serotonin, endogenous opiates), and neuroimmunological (humoral and cellular immunity) systems; the expansion beyond exclusive study of combat veterans to include posttraumatic stress disorder patients suffering from noncombat traumas; and the development of animal models of traumatic stress.     

颅内压监测辅助开颅血肿清除术治疗颅脑损伤患者效果及其预后影响因素分析

摘要 目的：分析颅内压监测辅助开颅血肿清除术治疗颅脑损伤患者效果及其预后影响因素。方法：选择我院自2019年1月至2023年3月接诊的135例拟接受开颅血肿清除术治疗的颅脑损伤患者作为研究对象,根据监测方式不同,分为常规组和监测组;其中常规组予以标准开颅血肿清除术治疗,监测组予以颅内压监测下控制性减压结合开颅血肿清除术治疗。比较两组手术前后的颅内压、格拉斯哥昏迷（GCS）评分、手术并发症发生情况,根据术后90 d的格拉斯哥预后评分（GOS）评分,计算两组的预后良好率,使用单因素分析和多因素Logistic回归分析预后的影响因素。结果：监测组术后即刻及术后12h的颅内压均小于常规组（P＜0.05）;监测组术后24 h、48 h的GCS评分均高于常规组（P＜0.05）;监测组术中低血压、急性脑膨出、颅内血肿、脑血管痉挛和非计划性再次手术的发生率均低于常规组（P＜0.05）;经单因素分析和多因素Logistic回归分析,年龄、入院GCS评分、脑疝、改良CT图像评分均是颅脑损伤患者预后的独立影响因素（P＜0.05）。结论：颅内压监测辅助开颅血肿清除术治疗颅脑损伤患者的效果显著,可以有效降低颅内压、减少并发症发生和改善预后,但预后受年龄、入院GCS评分、脑疝、改良CT图像评分的影响。     

Patient-specific non-linear finite element modelling for predicting soft organ deformation in real-time; Application to non-rigid neuroimage registration

Long computation times of non-linear (i.e. accounting for geometric and material non-linearity) biomechanical models have been regarded as one of the key factors preventing application of such models in predicting organ deformation for image-guided surgery. This contribution presents real-time patient-specific computation of the deformation field within the brain for six cases of brain shift induced by craniotomy (i.e. surgical opening of the skull) using specialised non-linear finite element procedures implemented on a graphics processing unit (GPU). In contrast to commercial finite element codes that rely on an updated Lagrangian formulation and implicit integration in time domain for steady state solutions, our procedures utilise the total Lagrangian formulation with explicit time stepping and dynamic relaxation. We used patient-specific finite element meshes consisting of hexahedral and non-locking tetrahedral elements, together with realistic material properties for the brain tissue and appropriate contact conditions at the boundaries. The loading was defined by prescribing deformations on the brain surface under the craniotomy. Application of the computed deformation fields to register (i.e. align) the preoperative and intraoperative images indicated that the models very accurately predict the intraoperative deformations within the brain. For each case, computing the brain deformation field took less than 4 s using an NVIDIA Tesla C870 GPU, which is two orders of magnitude reduction in computation time in comparison to our previous study in which the brain deformation was predicted using a commercial finite element solver executed on a personal computer.     

Drug and gene delivery to the brain: the vascular route

Brain drug development of either small molecule or large molecule (recombinant proteins, gene medicines) neurotherapeutics has been limited, owing to the restrictive transport properties of the brain microvasculature, which forms the blood-brain barrier (BBB) in vivo. Widespread drug delivery to the brain, while not feasible via craniotomy and intracerebral injection, is possible if the drug is delivered to brain via the transvascular route through the BBB. Novel brain drug delivery and drug targeting strategies can be developed from an understanding of the molecular and cellular biology of the brain microvascular and BBB transport processes.     

Combination radiotherapy in an orthotopic mouse brain tumor model

Glioblastoma multiforme (GBM) are the most common and aggressive adult primary brain tumors. In recent years there has been substantial progress in the understanding of the mechanics of tumor invasion, and direct intracerebral inoculation of tumor provides the opportunity of observing the invasive process in a physiologically appropriate environment. As far as human brain tumors are concerned, the orthotopic models currently available are established either by stereotaxic injection of cell suspensions or implantation of a solid piece of tumor through a complicated craniotomy procedure. In our technique we harvest cells from tissue culture to create a cell suspension used to implant directly into the brain. The duration of the surgery is approximately 30 minutes, and as the mouse needs to be in a constant surgical plane, an injectable anesthetic is used. The mouse is placed in a stereotaxic jig made by Stoetling (figure 1). After the surgical area is cleaned and prepared, an incision is made; and the bregma is located to determine the location of the craniotomy. The location of the craniotomy is 2 mm to the right and 1 mm rostral to the bregma. The depth is 3 mm from the surface of the skull, and cells are injected at a rate of 2 μl every 2 minutes. The skin is sutured with 5-0 PDS, and the mouse is allowed to wake up on a heating pad. From our experience, depending on the cell line, treatment can take place from 7-10 days after surgery. Drug delivery is dependent on the drug composition. For radiation treatment the mice are anesthetized, and put into a custom made jig. Lead covers the mouse's body and exposes only the brain of the mouse. The study of tumorigenesis and the evaluation of new therapies for GBM require accurate and reproducible brain tumor animal models. Thus we use this orthotopic brain model to study the interaction of the microenvironment of the brain and the tumor, to test the effectiveness of different therapeutic agents with and without radiation.     

Transaxillary subpectoral augmentation in the ptotic breast: augmentation by disruption of the extended pectoral fascia and parenchymal sweep

A new approach to transaxillary subpectoral breast augmentation based on an understanding of the anatomy of the extended pectoral fascia and the inframammary fold allows for the widespread application of this technique. Previous authors have stated that transaxillary augmentation is only applicable to a small subset of the general population and is contraindicated in mild degrees of ptosis or in large augmentations. The new approach, augmentation by disruption of the extended pectoral fascia technique and the parenchymal sweep maneuver, prevents high-riding implants and double folds. By disrupting the fascia, the lower portion of the implant is able to sit in a partially subglandular rather than subfascial plane. The anatomy and clinical implications of the extended pectoral fascia are discussed, as is the augmentation by disruption of the extended pectoral fascia technique. The parenchymal sweep maneuver is also described. Clinical cases are presented.     

Kinetic and equilibrium studies of bile salt–liposome interactions

Abstract

Research has suggested that exposure to sub-micellar concentrations of bile salts (BS) increases the permeability of lipid bilayers in a time-dependent manner. In this study, incubation of soy phosphatidylcholine small unilamellar vesicles (liposomes) with sub-micellar concentrations of cholate (C), deoxycholate (DC), 12-monoketocholate (MKC) or taurocholate (TC) in pH 7.2 buffer increased membrane fluidity and negative zeta potential in the order of increasing BS liposome-pH 7.2 buffer distribution coefficients (MKC?<?C?≈?TC?<?DC). In liposomes labeled with the dithionite-sensitive fluorescent lipid N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)phosphatidylethanolamine (NBD-PE) in both leaflets and equilibrated with sub-micellar concentrations of BS, fluorescence decline during continuous exposure to dithionite was biphasic involving a rapid initial phase followed by a slower second phase. Membrane permeability to dithionite as measured by the rate of the second phase increased in the order control?<?MKC?<?TC?～?C?<?DC. In liposomes labeled with NBD-PE in the inner leaflet only and incubated with the same concentrations of C, DC and MKC, membrane permeability to dithionite initially increased very rapidly in the order MKC?<?C?<?DC before impermeability to dithionite was restored after which fluorescence decline was consistent with NBD-PE flip-flop. For liposomes incubated with TC, membrane permeability to dithionite was only slightly increased and the decline in fluorescence was mainly the result of NBD-PE flip-flop. These results provide evidence that BS interact with lipid bilayers in a time-dependent manner that is different for conjugated and unconjugated BS. MKC appears to cause least disturbance to liposomal membranes but, when the actual MKC concentration in liposomes is taken into account, MKC is actually the most disruptive.     

Birefringence Changes of Dendrites in Mouse Hippocampal Slices Revealed with Polarizing Microscopy

Intrinsic optical signal (IOS) imaging has been widely used to map the patterns of brain activity in vivo in a label-free manner. Traditional IOS refers to changes in light transmission, absorption, reflectance, and scattering of the brain tissue. Here, we use polarized light for IOS imaging to monitor structural changes of cellular and subcellular architectures due to their neuronal activity in isolated brain slices. To reveal fast spatiotemporal changes of subcellular structures associated with neuronal activity, we developed the instantaneous polarized light microscope (PolScope), which allows us to observe birefringence changes in neuronal cells and tissues while stimulating neuronal activity. The instantaneous PolScope records changes in transmission, birefringence, and slow axis orientation in tissue at a high spatial and temporal resolution using a single camera exposure. These capabilities enabled us to correlate polarization-sensitive IOS with traditional IOS on the same preparations. We detected reproducible spatiotemporal changes in both IOSs at the stratum radiatum in mouse hippocampal slices evoked by electrical stimulation at Schaffer collaterals. Upon stimulation, changes in traditional IOS signals were broadly uniform across the area, whereas birefringence imaging revealed local variations not seen in traditional IOS. Locations with high resting birefringence produced larger stimulation-evoked birefringence changes than those produced at low resting birefringence. Local application of glutamate to the synaptic region in CA1 induced an increase in both transmittance and birefringence signals. Blocking synaptic transmission with inhibitors CNQX (for AMPA-type glutamate receptor) and D-APV (for NMDA-type glutamate receptor) reduced the peak amplitude of the optical signals. Changes in both IOSs were enhanced by an inhibitor of the membranous glutamate transporter, DL-TBOA. Our results indicate that the detection of activity-induced structural changes of the subcellular architecture in dendrites is possible in a label-free manner.     

The effect of hypoxia on brain gamma-aminobutyric acid levels

(1) Animals were exposed to hypoxic environments either by supplying them with breathing mixtures low in oxygen or by exposing them in a decompression chamber to simulated altitude. Both methods of producing hypoxia brought about significant increases in brain GABA levels. (2) Elevated GABA levels occurred in all species tested (mouse, hamster, rat, guinea pig, and rabbit) and reached maximal concentration 60 min after the initiation of breathing the hypoxic mixtures. Extension of the exposure beyond 60 min brought about a gradual decline in GABA level from the maximal value reached. (3) A linear relation was found between the oxygen content of the gas mixture and the elevation of GABA level. For guinea pigs, at least, the critical oxygen content required to prevent elevation of GABA level was 8.1 per cent.     

The postauricular fascial flap as an adjunct to Mustardé and Furnas type otoplasty.

Anterior riberation methods of otoplasty have been criticized because of the risk of anterior hematoma that can cause anterior skin necrosis, scarring, and even cartilage destruction caused by infection. As a result, cartilage-sparing otoplasty such as the Mustardé and Furnas types has been increasingly popular. However, postauricular suture extrusion may result, and recurrence rates of up to 25 percent have been recorded. In this study, cartilage-sparing otoplasty is refined by the addition of a postauricular fascial flap to reduce suture extrusion and recurrence rates. Fifty-one patients underwent otoplasty (45 bilateral, six unilateral). This technique involves the elevation of a fascial flap from the postauricular region. A new antihelical fold is then created by Mustardé sutures, and the conchal bowl is rotated by Furnas-type concha-mastoid sutures. The fascial flap is then advanced to cover the sutures with a supplementary vascularized layer to prevent suture extrusion. In addition, the advancement of the flap acts as a postauricular support to prevent recurrence. A natural-looking antihelical fold and helical rim is created by this technique. There were no hematomas. There was recurrence in eight ears (8 percent) in six patients. Two patients requested further surgery. No patients developed suture extrusion or granuloma. This is a simple and intrinsically safe procedure and does not cause irreparable complications such as anterior scarring or skin necrosis. The postauricular fascial flap seems to prevent suture extrusion. It may also help to reduce recurrence rates to acceptable levels.     

Influence of bile salt molecular species on cholesterol crystallization from supersaturated model biles

Time-sequential enzymatic determination of cholesterol (CH) crystals harvested by ultrafiltration, and concomitant polarizing light microscopy observations corroborated the striking importance of the bile salts (BS) species in determining CH crystals formation rate from supersaturated model biles incubated in vitro. The more hydrophilic tauroursodeoxycholate, taurohyocholate, glycohyocholate, taurohyodeoxycholate, glycohyodeoxycholate and glyco-3α, hydroxy-6 oxo-5ß-cholanate inhibited CH precipitation through the formation of a stabilized liquid-crystalline phase. In contrast, in all hydrophobic systems (taurine (T) and glycine (G) conjugates of cholate (C), deoxycholate (DC) and chenodeoxycholate (CDC)), CH crystals precipitated with time. When crystallized CH concentrations were plotted vs. time, the figures showed a sigmoidal pattern, consistent with the transition from metastable systems to stable equilibrium states. Over the equilibration period, the nucleation kinetics (as inferred from enzymatic measurements) and all crystallization events (as microscopically observed) were both shifted in time, depending on the BS species: they were earliest in CDC systems, then in DC systems, and finally in C systems. In the latter, the delay was clearly due to the formation of a transient labile liquid-crystalline phase. G-conjugation also induced a significant delay in CH precipitation, compared to T-conjugation. At last, maximum crystallized CH concentrations at equilibrium were in the decreasing order: C > CDC > DC and T-conjugates > G-homologues. All data are discussed in connection with BS hydrophobicities, with predictions from the phase equilibria of aqueous biliary lipid systems and with new insights into CH crystal habits.     

枕大孔区减压环枕筋膜松解术治疗CMⅠ-SM的疗效分析

目的：回顾分析枕大孔区减压环枕筋膜松解术治疗Chiari畸形Ⅰ型合并脊髓空洞症（CMⅠ—SM）的疗效及其适应症。方法：随访71例行枕大孔区减压环枕筋膜松解术治疗的CMⅠ-SM患者,回顾手术疗效,利用多因素Logistic回归分析探讨病程时间（A）、是否伴有后颅窝畸形（B）、是否有增厚的环枕筋膜（C）及减压后脑脊液搏动情况（D）与疗效的关系,继而推断枕大孔区减压环枕筋膜松解术的适应症。结果：本组患者症状改善49例,占73．1％;稳定15例,占22.4％;恶化3例,占4．5％。A、B与疗效不具有统计学意义;C、D与疗效具有统计学意义。结论：枕大孔区减压环枕筋膜松解术是治疗CMⅠ-SM较为合理的术式;术中观察有增厚的环枕筋膜和（或）减压后脑脊液搏动改善良好可作为选择该术式的适应症。