Construction of Switch Modules for CAR-T Cell Treatment Using a Site-Specific Conjugation System.

Chimeric antigen receptor T-cell (CAR-T cell) therapy has become a promising treatment option for B-cell hematological tumors. However, few optional target antigens and disease relapse due to loss of target antigens limit the broad clinical applicability of CAR-T cells. Here, we conjugated an antibody (Ab) fusion protein, consisting of an Ab domain and a SpyCatcher domain, with the FITC-SpyTag (FITC-ST) peptide to form a bispecific safety switch module using a site-specific conjugation system. We applied the safety switch module to target CD19, PDL1, or Her2-expressing tumor cells by constructing FMC63 (anti-CD19), antiPDL1, or ZHER (anti-Her2)-FITC-ST, respectively. Those switch modules significantly improved the cytotoxic effects of anti-FITC CAR-T cells on tumor cells. Additionally, we obtained the purified CD8+ T cells by optimizing a shorter version of the CD8-binding aptamer to generate anti-FITC CD8-CAR-T cells, which combined with the CD4-FITC-ST switch module (anti-CD4) to eliminate the CD4-positive tumor cells in vitro and in vivo. Overall, we established a novel safety switch module by site-specific conjugation to enhance the antitumor function of universal CAR-T cells, thereby expanding the application scope of CAR-T therapy and improving its safety and efficacy.

Stellate ganglion block ameliorated central post-stroke pain with comorbid anxiety and depression through inhibiting HIF-1α/NLRP3 signaling following thalamic hemorrhagic stroke.

BACKGROUND: Central post-stroke pain (CPSP) is an intractable and disabling central neuropathic pain that severely affects patients' lives, well-being, and socialization abilities. However, CPSP has been poorly studied mechanistically and its treatment remains challenging. Here, we used a rat model of CPSP induced by thalamic hemorrhage to investigate its underlying mechanisms and the effect of stellate ganglion block (SGB) on CPSP and emotional comorbidities. METHODS: Thalamic hemorrhage was produced by injecting collagenase IV into the ventral-posterolateral nucleus (VPL) of the right thalamus. The up-and-down method with von Frey hairs was used to measure the mechanical allodynia. Behavioral tests were carried out to examine depressive and anxiety-like behaviors including the open field test (OFT), elevated plus maze test (EPMT), novelty-suppressed feeding test (NSFT), and forced swim test (FST). The peri-thalamic lesion tissues were collected for immunofluorescence, western blotting, and enzyme-linked immunosorbent assay (ELISA). Genetic knockdown of thalamic hypoxia-inducible factor-1α (HIF-1α) and NOD-like receptor thermal protein domain associated protein 3 (NLRP3) with microinjection of HIF-1α siRNA and NLRP3 siRNA into the VPL of thalamus were performed 3 days before collagenase injection into the same regions. Microinjection of lificiguat (YC-1) and MCC950 into the VPL of thalamus were administrated 30 min before the collagenase injection in order to inhibited HIF-1α and NLRP3 pharmacologically. Repetitive right SGB was performed daily for 5 days and laser speckle contrast imaging (LSCI) was conducted to examine cerebral blood flow. RESULTS: Thalamic hemorrhage caused persistent mechanical allodynia and anxiety- and depression-like behaviors. Accompanying the persistent mechanical allodynia, the expression of HIF-1α and NLRP3, as well as the activities of microglia and astrocytes in the peri-thalamic lesion sites, were significantly increased. Genetic knockdown of thalamic HIF-1α and NLRP3 significantly attenuated mechanical allodynia and anxiety- and depression-like behaviors following thalamic hemorrhage. Further studies revealed that intra-thalamic injection of YC-1, or MCC950 significantly suppressed the activation of microglia and astrocytes, the release of pro-inflammatory cytokines, the upregulation of malondialdehyde (MDA), and the downregulation of superoxide dismutase (SOD), as well as mechanical allodynia and anxiety- and depression-like behaviors following thalamic hemorrhage. In addition, repetitive ipsilateral SGB significantly restored the upregulated HIF-1α/NLRP3 signaling and the hyperactivated microglia and astrocytes following thalamic hemorrhage. The enhanced expression of pro-inflammatory cytokines and the oxidative stress in the peri-thalamic lesion sites were also reversed by SGB. Moreover, LSCI showed that repetitive SGB significantly increased cerebral blood flow following thalamic hemorrhage. Most strikingly, SGB not only prevented, but also reversed the development of mechanical allodynia and anxiety- and depression-like behaviors induced by thalamic hemorrhage. However, pharmacological activation of thalamic HIF-1α and NLRP3 with specific agonists significantly eliminated the therapeutic effects of SGB on mechanical allodynia and anxiety- and depression-like behaviors following thalamic hemorrhage. CONCLUSION: This study demonstrated for the first time that SGB could improve CPSP with comorbid anxiety and depression by increasing cerebral blood flow and inhibiting HIF-1α/NLRP3 inflammatory signaling.

Spinal MCP-1 Contributes to Central Post-stroke Pain by Inducing Central Sensitization in Rats.

Central post-stroke pain (CPSP) is a highly refractory form of central neuropathic pain that has been poorly studied mechanistically. Recent observations have emphasized the critical role of the spinal dorsal horn in CPSP. However, the underlying mechanisms remain unclear. In this study, rats were subjected to thalamic hemorrhage to investigate the role of spinal monocyte chemoattractant protein-1 (MCP-1) and C-C motif chemokine receptor 2 (CCR2) in the development of CPSP. Immunohistochemical staining and ELISA were used to assess the expression changes of c-Fos, Iba-1, GFAP, MCP-1, and CCR2 in the dorsal horn of the lumbar spinal cord following thalamic hemorrhage, and the involvement of spinal MCP-1 in CPSP was examined by performing intrathecal anti-MCP-1 mAb injection to neutralize the spinal extracellular MCP-1. We demonstrated that intra-thalamic collagenase microinjection induced persistent bilateral mechanical pain hypersensitivity and facilitated the spontaneous pain behaviors evoked by intraplantar bee venom injection. Accompanying CPSP, the expression of c-Fos, Iba-1, and GFAP in the lumbar spinal dorsal horn was significantly increased up to 28 days post-intra-thalamic collagenase microinjection. Intrathecal injection of minocycline and fluorocitrate dramatically reverses the bilateral mechanical pain hypersensitivity. Moreover, intra-thalamic collagenase microinjection dramatically induced the up-regulation of MCP-1 but had no effect on the expression of CCR2 in the bilateral lumbar spinal dorsal horn, and MCP-1 was primarily localized in the neuron. Intrathecal injection of anti-MCP-1 mAb was also able to reverse CPSP and reduce the expression of c-Fos, Iba-1, and GFAP in the lumbar spinal dorsal horn. These findings indicated that spinal MCP-1 contributes to CPSP by mediating the activation of spinal neurons and glial cells following thalamic hemorrhage stroke, which may provide insights into pharmacologic treatment for CPSP.

Bilateral fronto-orbital advancement combined with cranial vault release using a free-floating bone flap technique for nonsyndromic unilateral coronal synostosis.

Background: The goals of operative treatment for unilateral coronal synostosis (UCS) are to improve appearance and allow unrestricted brain growth. However, for severe unilateral premature closure of the coronal suture, existing methods do not address the compression of the brain or expand the volume of the skull cavity. We report our retrospective experience with bilateral fronto-orbital advancement combined with cranial vault release using a free-floating bone flap (CVR + FFBF) technique and the resulting changes in the anterior cranial vault asymmetry index (ACVAI) and intracranial volume. Methods: Twenty patients with UCS who underwent bilateral fronto-orbital advancement combined with CVR + FFBF technique from April 2014 to May 2019 were included. Surgical efficacy was evaluated by the ACVAI and intracranial volume before the operation, 1 week after the operation, and at the last follow-up (average 19.8 months; range, 12 to 40 months). The measurement data are presented as the mean ± standard deviation and were statistically analyzed by t-test. Results: The ACVAI was 9.07%±3.55% before the operation, 3.56%±3.42% 1 week after the operation, and 3.13%±2.41% at the last follow-up. The ACVAI 1 week after the operation was significantly lower than that before the operation (t=4.827, P<0.001). There was no significant difference between the ACVAI 1 week after the operation and at the last follow-up (t=0.660, P=0.517). The intracranial volume was 1,027.85±112.25 mL in patients before the operation and 1,131.92±161.71 mL in the normal control group, which was a statistically significant difference (t=2.364, P=0.023). The intracranial volume significantly increased 1 week after surgery: 1,081.62±111.10 mL (t=8.703, P<0.001), and this trend continued at the last follow-up (1,386.90±119.30 mL) similarly to the normal control group (1,438.22±89.28 mL). At the last follow-up, there was no significant difference between the two groups (t=1.540, P=0.132). Conclusions: For the treatment of UCS, bilateral fronto-orbital advancement combined with CVR + FFBF technique offers functional and cosmetic outcomes in terms of intracranial volume expansion and fronto-orbital symmetry.

Ropivacaine-induced seizures evoked pain sensitization in rats: Participation of 5-HT/5-HT3R.

Due to the increasing use of local anesthetic techniques in various healthcare settings, local anesthetic toxicity still occurs. Seizures are the most common symptom of local anesthetic toxicity. The relationship between local anesthetic-induced seizures and the sensation of pain has not been established till now. Here, we assessed the development of pain hypersensitivity after ropivacaine-induced seizures (RIS) and the influence of RIS on incision-induced postsurgical pain and formalin-induced acute inflammatory pain. In addition, the involvement of spinal 5-HT/5-HT3R in RIS-induced pain sensitization was investigated. According to a sequential exploratory experimental strategy, we first calculated the 50% seizure dosage of ropivacaine to be 42.66 mg/kg (95% confidence interval: 40.19-45.28 mg/kg). We showed that RIS induced significant bilateral mechanical pain hypersensitivity that lasted around 5 days, accompanied by an increase in spinal 5-HT. Moreover, RIS considerably protracted postsurgical pain and enhanced formalin-induced spontaneous flinching in the second phase. Depletion of spinal 5-HT with intrathecal injection of 5,7-dihydroxytryptamine (5,7-DHT) reduced RIS-induced pain hypersensitivity and prevented the prolonging of postsurgical pain following RIS. Likewise, blocking spinal 5-HT3R by intrathecal administration of ondansetron reversed RIS-induced pain hypersensitivity and attenuated the pronociception of RIS in the formalin test. Our findings revealed that acute RIS led to pain hypersensitivity and had pronociceptive effects on incision-induced postsurgical pain and formalin-induced acute inflammatory pain. Moreover, our data implied that RIS-induced pain sensitization depends on spinal 5-HT/5-HT3R signaling. Thus, targeting the descending serotonergic facilitation system should be an important element of the precise treatment for local anesthetic toxicity.

Three-dimensional reconstruction and morphological characterization of pituitary macroadenomas.

INTRODUCTION: The aim was to investigate the relationship between the tumor (clinicopathologic and radiological) characteristics and the morphological parameters of pituitary macroadenoma or giant adenoma patients using a three-dimensional (3D) reconstructed model. MATERIAL AND METHODS: Magnetic resoanance imaging (MRI) was performed preoperatively; tumor grade was determined by the Knosp-Steiner classification and tumor morphology by the SIPAP classification. Pituitary adenomas and adjacent structures were reconstructed three-dimensionally by volume rendering. RESULTS: Fifty-two and 6 patients underwent surgery via the transnasal transsphenoidal or pterional approach, respectively. Knosp-Steiner grades I to IV adenomas were observed in 5.2%, 25.9%, 22.4% and 46.6% of the patients, respectively. The 3D model was reconstructed in all cases with superb delineation of tumor morphology and the spatial relationship between the tumor and adjacent tissues. Pituitary adenomas were categorized into intrasellar (13.8%), suprasellar (20.7%), infrasellar (17.2%), and lobulated adenomas (48.3%). Suprasellar adenomas had the smallest (2.27 ±3.22 cm(3)) and lobulated adenomas the largest volume (24.61 ±30.50 cm(3)). Intrasellar adenomas were all functioning, while 75%, 60% and 60.7%, respectively, of suprasellar, infrasellar and lobulated adenomas were nonfunctioning, with a significant association between tumor morphology and secretory function (p = 0.005). CONCLUSIONS: Three-dimensional reconstruction of pituitary macroadenomas offers a simplified morphological classification of pituitary adenomas and may be helpful for neurosurgeons to categorize and characterize pituitary adenomas.

Lateral Craniopharyngeal Canal: An Anatomical Cause of Spontaneous Rhinorrhea.

The aim of this report is to investigate the pathogenesis and surgical treatment of encephalocele located in the sphenoid sinus and presented with spontaneous rhinorrhea. The data of a patient with sphenoid sinus encephalocele was analyzed in association with the review of literature. The patient admitted to our clinic with rhinorrhea from the left nasal cavity. Cranial magnetic resonance imaging revealed bone defects in the left sphenoid sinus wall, and the presence of brain tissue and cerebrospinal fluid (CSF) in the sphenoid sinus. The patient underwent dural repair via left pterional approach. Rhinorrhea disappeared after surgery. The pathogenesis of the encephalocele in the sphenoid sinus is not clear. It may be related to the presence of lateral craniopharyngeal canal, extra-gasification in the sphenoid sinus, high intracranial pressure or other factors. It is very important to diagnose accurately the source of CSF fistula in preoperative period, choose the specific operation technique, and follow-up the patient for a long time period.

Changes of MDA and SOD in Brain Tissue after Secondary Brain Injury with Seawater Immersion in Rats.

AIM: To investigate the variation and significance of malondialdehyde (MDA) and superoxide dismutase (SOD) in brain tissue after secondary brain injury (SBI) with seawater immersion in rats. MATERIAL AND METHODS: We randomly divided 163 male Sprague Dawley rats into 4 groups, as normal (Group A), SBI (Group B), SBI with physiological saline immersion (Group C) and SBI with seawater immersion (Group D) groups. The animal model of ischemic SBI with seawater immersion was established based on the Marmarou's model of diffuse brain injury. The water content, and the MDA and SOD contents of brain tissue were detected at 1, 3, 6, 12, 24 and 48 hours after the injury. RESULTS: Compared to group A, there were significant changes of various indicators in group D after injury at 1 hour after injury (P < 0.05). The water content and MDA contents in brain tissue were persistently elevated and significantly higher than that in groups B and C at each time phase (P < 0.05). The SOD content showed a persistent decline and was significantly lower than that in groups B and C at each time phase (P < 0.05). The SOD content was negatively correlated with the MDA content with a correlation coefficient of -0.992 (P < 0.01). CONCLUSION: The SBI with seawater immersion is faster and more serious than the simple SBI.

A virtual reality model of the clivus and surgical simulation via transoral or transnasal route.

BACKGROUND: Neurosurgery in areas with restricted space and complicated anatomy can be greatly aided by the virtual reality (VR) technique. The clivus represents one of such challenging surgical areas, but its VR has not been established. The present study aimed to document a VR model of clival anatomy that may be useful in clival surgery. METHODS: High resolution CT angiography and MRI were used. The study included a total of 20 patients who did not have any obvious abnormalities detected in the oral, nasal, and clival areas. The images were fused with a Dextroscope. RESULTS: In the VR model, the key structures such as the clival bone, basilar artery, brainstem, pituitary gland, and paranasal sinuses were clearly observed. The morphology of the clivus and its spatial relationships with the neighboring structures were also illustrated. Visualization of the clival model can be made flexible from various planes, angles, or orientations. In addition, surgical access to the clivus via the transoral route or transnasal route was simulated in detail. CONCLUSION: The simulation of the VR model offers a straightforward, three-dimensional, interactive understanding of the size and shape of the clivus, and its relationships with the surrounding blood vessels and bones. It also demonstrates simulated operational procedures such as opening the surgical window, measuring the exposure distance and angles, and determining the critical boundaries in relation to key structures such as the brainstem and arteries. Digitalized VR modeling appears to be helpful for understanding the anatomy of the clivus and its surgical approaches.

Surgical therapy for craniocerebral firearm injury.

AIM: The current study aims to explore the clinical characteristics of craniocerebral firearm injury and to improve the diagnosis and treatment of this condition. MATERIAL AND METHODS: Data from 56 patients with craniocerebral firearm injury were analyzed retrospectively for projectile types, traumatic conditions, and treatment approaches. RESULTS: 43 patients exhibited intracranial foreign body residence. Of them, 40 were subjected to complete foreign body removal and 2 to partial removal, leaving 1 without receiving removal treatment. 54 patients (96.4%) survived and 2 (3.6%) died. Of the survivors, 36 (64.3%) recovered well, 15 (26.8%) were moderately disabled, 2 (3.6%) were severely disabled, and 1 (1.8%) lapsed into vegetative state. Patients receiving debridement within 8 h after injury had a significantly higher recovery rate than those receiving such treatment after 8 h (82.1% vs. 26.7%; P < 0.001). CONCLUSION: Craniocerebral firearm injury is characterized by rapid traumatic condition development as well as serious trauma and contamination. Accurately judging the traumatic condition and the ballistic tract, performing complete debridement as early as possible, reasonably deciding on the operative mode and approach for intracranial residing foreign body removal, and increasing vigilance regarding concomitant injuries are the keys to the improvement of the overall treatment of craniocerebral firearm injury.

Stereoscopic virtual reality models for planning tumor resection in the sellar region.

BACKGROUND: It is difficult for neurosurgeons to perceive the complex three-dimensional anatomical relationships in the sellar region. METHODS: To investigate the value of using a virtual reality system for planning resection of sellar region tumors. The study included 60 patients with sellar tumors. All patients underwent computed tomography angiography, MRI-T1W1, and contrast enhanced MRI-T1W1 image sequence scanning. The CT and MRI scanning data were collected and then imported into a Dextroscope imaging workstation, a virtual reality system that allows structures to be viewed stereoscopically. During preoperative assessment, typical images for each patient were chosen and printed out for use by the surgeons as references during surgery. RESULTS: All sellar tumor models clearly displayed bone, the internal carotid artery, circle of Willis and its branches, the optic nerve and chiasm, ventricular system, tumor, brain, soft tissue and adjacent structures. Depending on the location of the tumors, we simulated the transmononasal sphenoid sinus approach, transpterional approach, and other approaches. Eleven surgeons who used virtual reality models completed a survey questionnaire. Nine of the participants said that the virtual reality images were superior to other images but that other images needed to be used in combination with the virtual reality images. CONCLUSIONS: The three-dimensional virtual reality models were helpful for individualized planning of surgery in the sellar region. Virtual reality appears to be promising as a valuable tool for sellar region surgery in the future.

Diagnostic Significance of Intracystic Nodules on MRI in Rathke's Cleft Cyst.

Background and Purpose. To explore strategies for the diagnosis and treatment of Rathke's cleft cyst (RCC). Methods. The medical records of 24 patients with sellar RCC were retrospectively reviewed. Two patients had concomitant pituitary adenoma, 2 underwent transcranial surgery, and 22 underwent transsphenoidal surgery. The clinical features, especially the findings of intracystic nodules on MRI, were evaluated and compared with the pathological findings. Results. Preoperatively, only 2 patients were diagnosed with RCC or suspected RCC. Pre- and postoperative MRI images revealed 10 intracystic nodules in 9 (37.5%) patients. Two nodules had bull's eyelike changes. The signal intensity of the intracystic nodules varied on T1- and T2-weighted images. Not all nodules on T2-weighted images were visualized. Postoperative MRI revealed recurrence or residual lesion in 5 patients; none had new symptoms and a second surgery was not required. Conclusions. Identifying intracystic nodules is important in patients with sellar cystic lesions. Bull's eyelike change in an intracystic nodule on MRI, which is reported here for the first time, potentially might have value for confirming the diagnosis.

Virtual reality surgical anatomy of the sphenoid sinus and adjacent structures by the transnasal approach.

OBJECTIVE: To examine the three-dimensional virtual anatomical features of the sphenoid sinus and adjacent structures during virtual surgery and explore their relevance to actual transsphenoidal surgery. METHODS: CT images of the sphenoid sinus and surrounding structures from 28 Chinese adult patients were measured using a 16-slice helical CT scanner. Image analysis was performed using the volume-rendering method. Two experienced neurosurgeons wearing stereoscopic glasses performed virtual transsphenoidal surgery by the transnasal approach. RESULTS: The virtual anatomical features of the sphenoid sinus and the adjacent structures during virtual surgery were described. The distance from the sphenopalatine foramen to the left and right sphenoid ostium was 10.1 ± 2.7 mm and 10.5 ± 3.2 mm, respectively, to the left and right sphenoidal crest 12.9 ± 2.0 mm and 12.8 ± 2.2 mm, respectively, and to the left and right uncinate process 24.0 ± 1.9 mm and 23.9 ± 2.0 mm, respectively. The distance from the uncinate process to the medial and lateral edge of the most prominent part of the anterior bend of the cavernous internal carotid artery (ICA) was 33.7 ± 3.7 mm and 34.8 ± 3.7 mm, respectively, and the angle between the two lines was 9.7 ± 1.9°. CONCLUSION: The study provides virtual anatomical information about the sphenoid sinus and important surrounding structures that is essential for successful real life transsphenoidal surgery.

[Study on the adsorption behavior of nickel on potassium tetratitanate whisker by flame atomic absorption spectrometry].

The adsorption behavior of Ni (II) on potassium tetratitanate whisker was studied systemically by FAAS, seeing about the reasons for absorption, disentanglement and the effect of interfering ions on the recovery. The preconcentration method was simple, quick and had good selectivity. The adsorption rate of Ni(II) by potassium tetratitanate whisker was 100% at pH 5.0 and Ni(II) could be eluted from potassium tetratitanate whisker with hydrochloric acid (C: 0.5 mol x L(-1)), shake time exceeding 5 min, stick time exceeding 1.5 h, and the disentanglement ratio exceeding 90%. The relative standard deviation (RSD) was 2.6%. The results obtained indicate that the potassium tetratitanate whisker has good regenerate capability.

Microanatomy and surgical relevance of the olfactory cistern.

All surgical approaches to the anterior skull base involve the olfactory cistern and have the risk of damaging the olfactory nerve. The purpose of this study was to describe the microanatomical features of the olfactory cistern and discuss its surgical relevance. In this study, the olfactory cisterns of 15 formalin-fixed adult cadaveric heads were dissected using a surgical microscope. The results showed that the olfactory cistern was situated in the superficial part of the olfactory sulcus, which separated the gyrus retus from the orbital gyrus. In coronal section, the cistern was triangular in shape; its anterior part enveloped the olfactory bulbs and was high and broad; its posterior part was medial-superior to internal carotid artery and was also much broader. There were one or several openings in the inferior wall of the posterior part in 53.4% of the cisterns. The olfactory cistern communicated with the surrounding subarachnoind cisterns through these openings. The middle part of the olfactory cistern gradually narrowed down posteriorly. Most cisterns were spacious with a few fibrous trabeculas and bands between the olfactory nerves and cistern walls. However 23% of the cisterns were narrow with the cistern walls tightly encasing the olfactory nerve. There were two or three of arterial loops in each olfactory sulcus, from which long, fine olfactory arteries originated. The olfactory arteries coursed along the olfactory nerve and gave off many terminal branches to provide the main blood supply to the olfactory nerve in most cisterns, but the blood supply was in segmental style in a few cisterns. Moreover, the veins of the cistern appeared to be more segmental than the olfactory arteries in most cisterns. These results suggested that most olfactory cisterns are spacious with relatively independent blood supply, and it is reasonable to separate the olfactory tract with its independent blood supply from the frontal lobe by 1-2 cm in the subfrontal approach, the pterional approach, or anterior interhemispheric approach. However, in the minority of cases, separation of the olfactory tract is not safe because of the anterior origin of the olfactory arteries or segmental blood supply. It is difficult to separate the olfactory nerve without any damage to the olfactory nerve, even with very skilled hands.

[Combination of separation/preconcentration based on nanoscale TiO2 and FAAS for the simultaneous determination of Cr(III)/Cr(VI) in water].

The nanometer-sized materials have attracted much interest of analysts in recent years because of their special physicschemistry characteristics. As the scale decreases to nanometer grade, the number of atoms on the surface increases remarkably, resulting in the unsaturation. This makes the nanometer-sized materials have a high adsorptivity for the metal atoms. In the present paper, the nanometer-sized TiO2 was applied in the separation and preconcentration of Cr(III) and Cr(VI) in water. The influence of pH on the adsorption of Cr(III) and Cr(VI) was studied. When pH is larger than 6, 90%, Cr(III) is adsorbed onto the nanometer-sized material surface, while is basically not adsorbed in aqueous solution. Therefore, the separation of Cr(III) and Cr(VI) is achieved. At the pH of 6.5, Cr(III) was adsorbed by nanometer-sized TiO2 and desorbed with 2.0 mol x L(-1) HCl, in which the Cr(III) could be preconcentrated. The Cr(III) solution, as well as the Cr(VI) aqueous solution was determined by FAAS. The detection limits of Cr(M) and Cr(VI) were 41 and 57 ng x mL(-1), respectively. And the linear ranges for Cr(III) and Cr(VI) were 0-9.0 microg x mL(-1) and 0.1-10 microg x mL(-1) with a RSDs of 2.6% and 3.4% (n=6, c = 2.0 microg x mL(-1), respectively. This method was applied in the simultaneous determination of Cr(III) and Cr(VI) in the industrial wastewater and river water, and the satisfactory recovery results were obtained.

[Pathological changes in rabbit brain after traumatic head injuries with seawater immersion].

OBJECTIVE: To observe the pathological impact of seawater on rabbit brain tissue with severe traumatic injury. METHODS: Modified rabbit models of severe brain injury was utilized, in which the damaged brain tissues were subjected to immersion with fresh seawater for 30 min. A control group was set up in which the trauma was induced without subsequent seawater immersion. Tissue sampling was performed at the brain injury sites at 0, 3, 8 h after seawater immersion and the pathological changes in the brain tissues were observed by means of HE staining. RESULTS: Severe traumatic brain edema occurred in both of the two groups, but the onset time of edema differed. In the control group, brain edema was obvious at 3 h after treatment and hardly aggravated at hour 8; while in seawater treatment group, severe brain edema occurred at 8 h after the treatment and aggravated progressively. CONCLUSION: Seawater immersion delays the onset and peak of traumatic brain edema following severe brain injuries, but can eventually aggravate the traumatic edema.