Hypoxic-Ischemic Brain Injury in ECMO: Pathophysiology, Neuromonitoring, and Therapeutic Opportunities.

Extracorporeal membrane oxygenation (ECMO), in conjunction with its life-saving benefits, carries a significant risk of acute brain injury (ABI). Hypoxic-ischemic brain injury (HIBI) is one of the most common types of ABI in ECMO patients. Various risk factors, such as history of hypertension, high day 1 lactate level, low pH, cannulation technique, large peri-cannulation PaCO2 drop (∆PaCO2), and early low pulse pressure, have been associated with the development of HIBI in ECMO patients. The pathogenic mechanisms of HIBI in ECMO are complex and multifactorial, attributing to the underlying pathology requiring initiation of ECMO and the risk of HIBI associated with ECMO itself. HIBI is likely to occur in the peri-cannulation or peri-decannulation time secondary to underlying refractory cardiopulmonary failure before or after ECMO. Current therapeutics target pathological mechanisms, cerebral hypoxia and ischemia, by employing targeted temperature management in the case of extracorporeal cardiopulmonary resuscitation (eCPR), and optimizing cerebral O2 saturations and cerebral perfusion. This review describes the pathophysiology, neuromonitoring, and therapeutic techniques to improve neurological outcomes in ECMO patients in order to prevent and minimize the morbidity of HIBI. Further studies aimed at standardizing the most relevant neuromonitoring techniques, optimizing cerebral perfusion, and minimizing the severity of HIBI once it occurs will improve long-term neurological outcomes in ECMO patients.

Lower Oxygen Tension and Intracranial Hemorrhage in Veno-venous Extracorporeal Membrane Oxygenation.

INTRODUCTION AND METHODS: We examined the relationship between 24-h pre- and post-cannulation arterial oxygen tension (PaO2) and arterial carbon dioxide tension (PaCO2) and subsequent acute brain injury (ABI) in patients receiving veno-venous extracorporeal membrane oxygenation (VV-ECMO) with granular arterial blood gas (ABG) data and institutional standardized neuromonitoring. RESULTS: Eighty-nine patients underwent VV-ECMO (median age = 50, 63% male). Twenty (22%) patients experienced ABI; intracranial hemorrhage (ICH) was the most common diagnosis (n = 14, 16%). Lower post-cannulation PaO2 levels were significantly associated with ICH (66 vs. 81 mmHg, p = 0.007) and a post-cannulation PaO2 level < 70 mmHg was more frequent in these patients (71% vs. 33%, p = 0.007). PaCO2 parameters were not associated with ABI. By multivariable logistic regression, hypoxemia post-cannulation increased the odds of ICH (OR = 5.06, 95% CI:1.41-18.17; p = 0.01). CONCLUSION: In summary, lower oxygen tension in the 24-h post-cannulation was associated with ICH development. The precise roles of peri-cannulation ABG changes deserve further investigation, as they may influence the management of VV-ECMO patients.

The neuronal (pro)renin receptor and astrocyte inflammation in the central regulation of blood pressure and blood glucose in mice fed a high-fat diet.

We report here that the neuronal (pro)renin receptor (PRR), a key component of the brain renin-angiotensin system (RAS), plays a critical role in the central regulation of high-fat-diet (HFD)-induced metabolic pathophysiology. The neuronal PRR is known to mediate formation of the majority of angiotensin (ANG) II, a key bioactive peptide of the RAS, in the central nervous system and to regulate blood pressure and cardiovascular function. However, little is known about neuronal PRR function in overnutrition-related metabolic physiology. Here, we show that PRR deletion in neurons reduces blood pressure, neurogenic pressor activity, and fasting blood glucose and improves glucose tolerance without affecting food intake or body weight following a 16-wk HFD. Mechanistically, we found that a HFD increases levels of the PRR ligand (pro)renin in the circulation and hypothalamus and of ANG II in the hypothalamus, indicating activation of the brain RAS. Importantly, PRR deletion in neurons reduced astrogliosis and activation of the astrocytic NF-κB p65 (RelA) in the arcuate nucleus and the ventromedial nucleus of the hypothalamus. Collectively, our findings indicate that the neuronal PRR plays essential roles in overnutrition-related metabolic pathophysiology.

Combined Therapy Sensitivity Index Based on a 13-Gene Signature Predicts Prognosis for IDH Wild-type and MGMT Promoter Unmethylated Glioblastoma Patients.

Glioblastoma (GBM) is one of the lethal tumors with poor prognosis. However, prognostic prediction approaches need to be further explored. Therefore, we developed an evaluation system that could be used for prognostic prediction of GBM patients. Published mRNA expression datasets from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) and Chinese Glioma Genome Atlas (CGGA) were analyzed. Quantitative Realtime-PCR of signature genes and molecular aberrations of 178 Xiangya GBM patients were used for confirmation. Gene set enrichment analysis (GSEA) was performed for functional annotation. As a result, we established a 13-gene signature which named Combined Therapy Sensitivity Index (CTSI). Based on a cutoff point, we divided patients into high-risk group and low-risk group. Based on Kaplan-Meier analysis and multivariate Cox regression analysis, we found that patients in the high-risk group had a shorter overall survival time than patients in the low-risk group (p<0.001 in TCGA and CGGA datasets, p=0.047 in GSE4271 dataset, p=0.008 in Xiangya GBM cohort, HR: 1.65-3.42). By comparing the status of IDH mutation, TERT promoter mutation (TERTp-mut) and MGMT promoter methylation, CTSI was predictable in IDH wild-type (IDH-wt)/MGMT promoter unmethylated (MGMTp-unmeth) patients (p=0.037 in IDH-wt/TERTp-mut/MGMTp-unmeth subgroup, HR: 1.98; p=0.032 in IDH-wt/TERTp-wt/MGMTp-unmeth subgroup, HR: 2.09). Based on GESA, the Gene Ontology (GO) gene sets were enriched differently between CTSI high-risk and low-risk groups. Our results showed CTSI risk score can predict the prognosis of IDH-wt/MGMTp-unmeth GBM patients. Based on CTSI, combined with the status of IDH mutation, TERT promoter mutation and MGMT promoter methylation, a stepwise prognosis evaluation system which can provide precise prognosis prediction for GBM patients was established.

Postnatal Restriction of Activity-Induced Ca2+ Responses to Schwann Cells at the Neuromuscular Junction Are Caused by the Proximo-Distal Loss of Axonal Synaptic Vesicles during Development.

Terminal or perisynaptic Schwann cells (TPSCs) are nonmyelinating, perisynaptic glial cells at the neuromuscular junction (NMJ) that respond to neural activity by increasing intracellular calcium (Ca2+) and regulate synaptic function. The onset of activity-induced TPSC Ca2+ responses, as well as whether axonal Schwann cells (ASCs) along the nerve respond to nerve stimulation during development, is unknown. Here, we show that phrenic nerve stimulation in developing male and female mice elicited Ca2+ responses in both ASCs and TPSCs at embryonic day 14. ASC responses were lost in a proximo-distal gradient over time, but could continue to be elicited by bath application of neurotransmitter, suggesting that a loss of release rather than a change in ASC competence accounted for this response gradient. Similar to those of early postnatal TPSCs, developing ASC/TPSC responses were mediated by purinergic P2Y1 receptors. The loss of ASC Ca2+ responses was correlated to the proximo-distal disappearance of synaptophysin immunoreactivity and synaptic vesicles in phrenic axons. Accordingly, developing ASC Ca2+ responses were blocked by botulinum toxin. Interestingly, the loss of ASC Ca2+ responses was also correlated to the proximo-distal development of myelination. Finally, compared with postnatal TPSCs, neonatal TPSCs and ASCs displayed Ca2+ signals in response to lower frequencies and shorter durations of nerve stimulation. Together, these results with GCaMP3-expressing Schwann cells provide ex vivo evidence that both axons and presynaptic terminals initially exhibit activity-induced vesicular release of neurotransmitter, but that the subsequent loss of axonal synaptic vesicles accounts for the postnatal restriction of vesicular release to the NMJ.SIGNIFICANCE STATEMENT Neural activity regulates multiple aspects of development, including myelination. Whether the excitation of developing neurons in vivo results in the release of neurotransmitter from both axons and presynaptic terminals is unclear. Here, using mice expressing the genetically encoded calcium indicator GCaMP3 in Schwann cells, we show that both terminal/perisynaptic Schwann cells at the diaphragm neuromuscular junction and axonal Schwann cells along the phrenic nerve exhibit activity-induced calcium responses early in development, mediated by the vesicular release of ATP from the axons of motor neurons acting on P2Y1 receptors. These ex vivo findings corroborate classic in vitro studies demonstrating transmitter release by developing axons, and thus represent a tool to study the mechanisms and significance of this process during embryonic development.

Activity-induced Ca2+ signaling in perisynaptic Schwann cells of the early postnatal mouse is mediated by P2Y1 receptors and regulates muscle fatigue.

Perisynaptic glial cells respond to neural activity by increasing cytosolic calcium, but the significance of this pathway is unclear. Terminal/perisynaptic Schwann cells (TPSCs) are a perisynaptic glial cell at the neuromuscular junction that respond to nerve-derived substances such as acetylcholine and purines. Here, we provide genetic evidence that activity-induced calcium accumulation in neonatal TPSCs is mediated exclusively by one subtype of metabotropic purinergic receptor. In P2ry1 mutant mice lacking these responses, postsynaptic, rather than presynaptic, function was altered in response to nerve stimulation. This impairment was correlated with a greater susceptibility to activity-induced muscle fatigue. Interestingly, fatigue in P2ry1 mutants was more greatly exacerbated by exposure to high potassium than in control mice. High potassium itself increased cytosolic levels of calcium in TPSCs, a response which was also reduced P2ry1 mutants. These results suggest that activity-induced calcium responses in TPSCs regulate postsynaptic function and muscle fatigue by regulating perisynaptic potassium.

Increased (pro)renin receptor expression in the subfornical organ of hypertensive humans.

The central nervous system plays an important role in essential hypertension in humans and in animal models of hypertension through modulation of sympathetic activity and Na+ and body fluid homeostasis. Data from animal models of hypertension suggest that the renin-angiotensin system in the subfornical organ (SFO) of the brain is critical for hypertension development. We recently reported that the brain (pro)renin receptor (PRR) is a novel component of the brain renin-angiotensin system and could be a key initiator of the pathogenesis of hypertension. Here, we examined the expression level and cellular distribution of PRR in the SFO of postmortem human brains to assess its association with the pathogenesis of human hypertension. Postmortem SFO tissues were collected from hypertensive and normotensive human subjects. Immunolabeling for the PRR and a retrospective analysis of clinical data were performed. We found that human PRR was prominently expressed in most neurons and microglia, but not in astrocytes, in the SFO. Importantly, PRR levels in the SFO were elevated in hypertensive subjects. Moreover, PRR immunoreactivity was significantly correlated with systolic blood pressure but not body weight, age, or diastolic blood pressure. Interestingly, this correlation was independent of antihypertensive drug therapy. Our data indicate that PRR in the SFO may be a key molecular player in the pathogenesis of human hypertension and, as such, could be an important focus of efforts to understand the neurogenic origin of hypertension. NEW & NOTEWORTHY This study provides evidence that, in the subfornical organ of the human brain, the (pro)renin receptor is expressed in neurons and microglia cells but not in astrocytes. More importantly, (pro)renin receptor immunoreactivity in the subfornical organ is increased in hypertensive humans and is significantly correlated with systolic blood pressure.

Microscopic surgery for pituitary adenomas to preserve the pituitary gland and stalk.

Surgery is the primary treatment of choice for all symptomatic pituitary adenomas except prolactinomas. Common postoperative complications include endocrinopathies, vision impairment and cerebrospinal fluid leak. The present study assessed 153 continuous microscopic surgeries for pituitary adenomas performed by an author of the present study between 2010 to 2014. Patients underwent either transphenoidal or transcranial surgery depending on their individual tumor characteristics. Five typical cases are presented in the present study and intraoperative identification and preservation of the gland and stalk were discussed. Postoperative complications were analyzed and compared with the literature. In the present analysis, 90.2% patients received transphenoidal surgery, and the rest underwent transcranial operation. Gross total resection was achieved in 81.2% patients in the transphenoidal group and 46.7% patients in the transcranial group. No new hypopituitarism or worsening of the pre-existing pituitary dysfunctions was detected. The most common postoperative endocrinopathy was diabetes insipidus (transphenoidal group, 4.3%; transcranial group, 26.7%). All patients were fully recovered prior to discharge. The findings indicated the importance of pituitary gland and stalk preservation during the microscopic surgery to minimize postoperative morbidity and mortality, without compromising the extent of tumor resection. Based on preoperative imaging characteristics and intraoperative observations, surgeons should try all possible means to preserve the pituitary stalk and gland during surgery in order to minimize postoperative endocrinopathies and improve quality of life.

Expression of schizophrenia biomarkers in extraocular muscles from patients with strabismus: an explanation for the link between exotropia and schizophrenia?

Recent studies have implicated exotropia as a risk factor for schizophrenia. We determined whether schizophrenia biomarkers have abnormal levels of expression in extraocular muscles from patients with strabismus and explored whether differences in gene expression between medial and lateral rectus muscles may explain the specific association of schizophrenia with exotropia but not esotropia. Samples from horizontal extraocular muscles were obtained during strabismus surgery and compared with age- and muscle type-matched normal muscles from organ donors. We used PCR arrays to identify differences in gene expression among 417 signaling molecules. We then focused on established schizophrenia-related growth factors, cytokines, and regulators of the extracellular matrix. Among 36 genes with significantly altered gene expression in dysfunctional horizontal rectus muscles, over one third were schizophrenia-related: CTGF, CXCR4, IL1B, IL10RA, MIF, MMP2, NPY1R, NRG1, NTRK2, SERPINA3, TIMP1, TIMP2, and TNF (adjusted p value ≤ 0.016667). By PCR array, expression of three of these genes was significantly different in medial rectus muscles, while eleven were significantly altered in lateral rectus muscles. Comparing baseline levels between muscle types, three schizophrenia-related genes (NPY1R, NTRK2, TIMP2) had lower levels of expression in medial rectus muscles. Despite the surprisingly large number of schizophrenia-related genes with altered gene expression levels in dysfunctional muscles, the lack of specificity for medial rectus muscles undermines a model of shared, region-specific gene expression abnormalities between exotropia and schizophrenia, but rather suggests consideration of the alternative model: that exotropia-induced aberrant early visual experiences may enable and/or contribute as a causative factor to the development of schizophrenia.

Solitary Fibrous Tumor of Central Nervous System: Clinical and Prognostic Study of 24 Cases.

BACKGROUND: Solitary fibrous tumors (SFTs) are rare mesenchymal tumors that occasionally occur in the central nervous system (CNS). It is difficult to fully understand their clinical characteristics, partly due to a limited number of reported cases. METHODS: We reviewed 24 patients admitted to our institution between 2009 and 2016 with CNS solitary fibrous tumors. We reviewed and analyzed patient profiles, such as demographics, presentations, imaging studies, extent of resection, and adjuvant treatment. Differences between malignant and benign SFTs were assessed using the χ2 test or Student's t-test. Kaplan-Meier analysis was used to estimate the disease-free survival (DFS) rate. The multivariate Cox regression analysis was performed to evaluate the possible predictive value of the DFS rate of the previously mentioned covariates. RESULTS: A total of 13 men and 11 women were enrolled in the study (the average age was 43). The median follow-up time was 58 months. Twenty-one patients underwent gross total resection (GTR), and 3 patients received a subtotal resection (STR). The tumors in 15 patients (62.5%) were atypical or malignant. One patient (4.2%) suffered SFT-related death (multiple organ failure by tumor metastasis), and 3 patients (12.5%) experienced tumor recurrence. We found that a large tumor size (≥10 cm, P < 0.001) and STR (P < 0.001) were negatively associated with the DFS rate. CONCLUSION: CNS SFTs are rare, slow-growing, less aggressive, and recrudescent tumors. Complete resection is the most effective therapy. Large tumor size and STRs might shorten DFS time.

EGFL7 is an intercellular EGFR signal messenger that plays an oncogenic role in glioma.

Epidermal Growth Factor like domain 7 (EGFL7), also known as Vascular Endothelial-statin (VE-statin), is a secreted angiogenic factor. Recent data have demonstrated the potential oncogenic role and prognostic significance of EGFL7 in several human cancers. However, the clinical signature and further mechanisms of EGFL7's function in gliomagenesis are poorly understood. In the present study, we found that increased EGFL7 expression was associated with tumor grade. High expression of EGFL7 in EGFRvIII-positive glioblastoma multiforme (GBM) was determined to be a strong and independent risk factor for reduced life expectancy. EGFRvIII cells can secrete the EGFL7 protein to improve the activity of the ß-catenin/TCF4 Transcription complex in EGFRwt cells, thus promoting their own EGFL7 expression. Our research demonstrates that oncogenic activation of EGFRwt in GBM is likely maintained by a continuous EGFL7 autocrine flow line, and may be an attractive target for therapeutic intervention.

Altered Protein Composition and Gene Expression in Strabismic Human Extraocular Muscles and Tendons.

PURPOSE: To determine whether structural protein composition and expression of key regulatory genes are altered in strabismic human extraocular muscles. METHODS: Samples from strabismic horizontal extraocular muscles were obtained during strabismus surgery and compared with normal muscles from organ donors. We used proteomics, standard and customized PCR arrays, and microarrays to identify changes in major structural proteins and changes in gene expression. We focused on muscle and connective tissue and its control by enzymes, growth factors, and cytokines. RESULTS: Strabismic muscles showed downregulation of myosins, tropomyosins, troponins, and titin. Expression of collagens and regulators of collagen synthesis and degradation, the collagenase matrix metalloproteinase (MMP)2 and its inhibitors, tissue inhibitor of metalloproteinase (TIMP)1 and TIMP2, was upregulated, along with tumor necrosis factor (TNF), TNF receptors, and connective tissue growth factor (CTGF), as well as proteoglycans. Growth factors controlling extracellular matrix (ECM) were also upregulated. Among 410 signaling genes examined by PCR arrays, molecules with downregulation in the strabismic phenotype included GDNF, NRG1, and PAX7; CTGF, CXCR4, NPY1R, TNF, NTRK1, and NTRK2 were upregulated. Signaling molecules known to control extraocular muscle plasticity were predominantly expressed in the tendon rather than the muscle component. The two horizontal muscles, medial and lateral rectus, displayed similar changes in protein and gene expression, and no obvious effect of age. CONCLUSIONS: Quantification of proteins and gene expression showed significant differences in the composition of extraocular muscles of strabismic patients with respect to important motor proteins, elements of the ECM, and connective tissue. Therefore, our study supports the emerging view that the molecular composition of strabismic muscles is substantially altered.

Sample Level Enrichment Analysis of KEGG Pathways Identifies Clinically Relevant Subtypes of Glioblastoma.

Background: Glioblastoma is the most lethal primary brain tumor in adults. Aberrant signal transduction pathways, associated with the progression of glioblastoma, have been identified recently and may offer a potential gene therapy strategy. Methods and Findings: We first used the sample level enrichment analysis to transfer gene expression profile of TCGA dataset into pathway enrichment z-score matrix. Then, we classified glioblastoma into five subtypes (Cluster A to Cluster E) by the consensus clustering and silhouette analysis. Principle component analysis showed the five subtype could be separated by first three principle components. Integrative omics data showed that mesenchymal subtype was rich in Cluster A, neural subtype was centered in Cluster D and proneural subtype was gathered in Cluster E, while Cluster E showed a high percentage of G-CIMP subtype. Additionally, according to analyze the overall survival and progression free survival of each subtype by Kaplan-Merie analysis and Cox hazard proportion model, we identified Cluster D and Cluster E received a better prognosis. Conclusions: We report a clinically relevant classification of glioblastoma based on sample level KEGG pathway enrichment profile and this novel classification system provided new insights into the heterogeneity of glioblastoma, and may be used as an important clinical tool to predict the prognosis.

Microsurgical Management of Craniopharyngiomas via a Unilateral Subfrontal Approach: A Retrospective Study of 177 Continuous Cases.

OBJECTIVE: To evaluate the outcomes of 177 cases of craniopharyngioma (CP) treated via a unilateral subfrontal approach. METHODS: A total of 177 continuous microscopic surgeries were performed by the senior author (Y.X.). The tumors were divided into 6 groups using the diaphragm sellae and the third ventricle floor as the anatomic references. The preoperative, postoperative, and long-term follow-up data were analyzed to evaluate the extent of tumor resection, recurrence, and functional status. RESULTS: The subfrontal-basal approach was used in 169 (91.4%) cases. Total resection was achieved in 167 (94.4%) cases. A total of 158 patients were followed from 6 to 130 months. There were 3 perioperative and 23 delayed deaths. Twenty-two patients had tumor recurrence (12.7%). The progression-free survival was 80% at 5 years and 72% at 10 years. The overall survival was 84.0% at 2.5 years and 83.2% at 10 years. There was a significant increase of pituitary dysfunction after total resection. Neurologic function was stable in most patients. Rate of hypothalamic dysfunction and mortality were higher in patients with intraventricular CPs. Of the surviving patients, 91.8% were living independently with acceptable morbidities at the end of the study. CONCLUSIONS: Most CPs extend along the intrasellar-suprasellar-third ventricle axis. A subfrontal-basal approach is a simple, safe, and effective approach to resecting CPs extending along the vertical axis. A translamina terminalis approach is an ideal corridor to resect intraventricular CP. The benefit of radical resection remains controversial, especially for CPs involving the infundibulotuberal region.

Ectopic recurrence of pediatric craniopharyngiomas after gross total resection: a report of two cases and a review of the literature.

INTRODUCTION: Ectopic recurrent craniopharyngioma is rare. We reported two pediatric cases and reviewed the related literature. METHOD: We retrospectively studied 177 craniopharyngioma cases treated by the senior author (Yuan X) between years 2003 and 2013. Two ectopic recurrent craniopharyngiomas were identified. One was discovered under the right frontal lobe and the other was found in the fourth ventricle. Both patients underwent a second radical resection without complications. Then we conducted an extensive review of peer-reviewed, English-language literatures in the US National Library of Medicine, focusing on the treatment modalities, recurrent sites, and clinical outcomes. RESULTS: Sixty ectopic recurrent tumors have been reported so far (including this study). Thirty-three tumors were located in the previous surgical corridors and 27 were disseminated along the cerebrospinal fluid pathway. All recurrent tumors were surgically removed. The gross total resection (GTR) rates were 87 and 63 %, respectively. CONCLUSION: The natural course of recurrent ectopic craniopharyngiomas is progressive. GTR is the treatment of choice. Regular follow-ups are strongly recommended to detect any further recurrence.

Structural and Functional Abnormalities of the Neuromuscular Junction in the Trembler-J Homozygote Mouse Model of Congenital Hypomyelinating Neuropathy.

Mutations in peripheral myelin protein 22 (PMP22) result in the most common form of Charcot-Marie-Tooth (CMT) disease, CMT1A. This hereditary peripheral neuropathy is characterized by dysmyelination of peripheral nerves, reduced nerve conduction velocity, and muscle weakness. APMP22 point mutation in L16P (leucine 16 to proline) underlies a form of human CMT1A as well as the Trembler-J mouse model of CMT1A. Homozygote Trembler-J mice (Tr(J)) die early postnatally, fail to make peripheral myelin, and, therefore, are more similar to patients with congenital hypomyelinating neuropathy than those with CMT1A. Because recent studies of inherited neuropathies in humans and mice have demonstrated that dysfunction and degeneration of neuromuscular synapses or junctions (NMJs) often precede impairments in axonal conduction, we examined the structure and function of NMJs in Tr(J)mice. Although synapses appeared to be normally innervated even in end-stage Tr(J)mice, the growth and maturation of the NMJs were altered. In addition, the amplitudes of nerve-evoked muscle endplate potentials were reduced and there was transmission failure during sustained nerve stimulation. These results suggest that the severe congenital hypomyelinating neuropathy that characterizes Tr(J)mice results in structural and functional deficits of the developing NMJ.

Pituitary stalk management during the microsurgery of craniopharyngiomas.

In the present study, 203 patients that had previously undergone microsurgery for craniopharyngiomas (CPs) between 1992 and 2012 were analyzed retrospectively on a long-term follow-up basis to investigate the differences in the recurrence rate and endocrine function between patients with preserved and resected pituitary stalks. To summarize the possible outcomes of microsurgery, the 203 patients were divided into 2 groups: Group A that had preserved pituitary stalks and Group B that had undergone resections of the pituitary stalk. Tumor origins and the involvement of the pituitary stalk during surgery were observed. From 2010 onwards, an ultra-electron microscope was used postoperatively to detect whether pituitary stalk specimens were infiltrated or invaded with tumor cells. Long-term follow-up observations of the patients included tumor recurrence, postoperative endocrine dysfunction and visual acuity and field. Among the 203 patients, 175 patients received gross-total resection (GTR) (175/203, 86.2%), 28 patients underwent subtotal resection (28/203, 13.8%) and 34 patients had surgery that preserved the pituitary stalk (34/203, 16.7%). There was no significant difference in the recurrence rate between Group A (4/34, 11.8%) and the patients in Group B (10/123, 8.1%) who underwent GTR and also received follow-ups. Of the 157 patients who were followed up, 91 individuals underwent endocrine evaluation and the outcome was divided into normal, satisfactory and poor grades. The results for Group A were 5, 18 and 0, respectively, while the results for Group B were 1, 60 and 7, respectively, which showed a statistically significant difference between the groups. Pituitary stalk specimens of 15 patients were studied postoperatively using an ultra-electron microscope and all samples showed tumor cells had invaded the pituitary stalk (15/15, 100%). Total resections of CPs with the pituitary stalk were recommended if the pituitary stalk was intraoperatively invaded. In cases where the pituitary stalk was not involved, microsurgical excisions preserving the pituitary stalk were preferred, as there was no significant increase in the recurrence rate and the patients experienced less endocrine dysfunction.

Differences in gene expression between strabismic and normal human extraocular muscles.

PURPOSE: Strabismic extraocular muscles (EOMs) differ from normal EOMs in structural and functional properties, but the gene expression profile of these two types of EOM has not been examined. Differences in gene expression may inform about causes and effects of the strabismic condition in humans. METHODS: EOM samples were obtained during corrective surgery from patients with horizontal strabismus and from deceased organ donors with normal EOMs. Microarrays and quantitative PCR identified significantly up- and down-regulated genes in EOM samples. Analysis was performed on probe sets with more than 3-fold differential expression between normal and strabismic samples, with an adjusted P value of ≤ 0.05. RESULTS: Microarray analysis showed that 604 genes in these samples had significantly different expression. Expression predominantly was upregulated in genes involved in extracellular matrix structure, and down-regulated in genes related to contractility. Expression of genes associated with signaling, calcium handling, mitochondria function and biogenesis, and energy homeostasis also was significantly different between normal and strabismic EOM. Skeletal muscle PCR array identified 22 (25%) of 87 muscle-specific genes that were significantly down-regulated in strabismic EOMs; none was significantly upregulated. CONCLUSIONS: Differences in gene expression between strabismic and normal human EOMs point to a relevant contribution of the peripheral oculomotor system to the strabismic condition. Decreases in expression of contractility genes and increases of extracellular matrix-associated genes indicate imbalances in EOM structure. We conclude that gene regulation of proteins fundamental to contractile mechanics and extracellular matrix structure is involved in pathogenesis and/or consequences of strabismus, suggesting potential novel therapeutic targets.

Analysis of spontaneous and nerve-evoked calcium transients in intact extraocular muscles in vitro.

Extraocular muscles (EOMs) have unique calcium handling properties, yet little is known about the dynamics of calcium events underlying ultrafast and tonic contractions in myofibers of intact EOMs. Superior oblique EOMs of juvenile chickens were dissected with their nerve attached, maintained in oxygenated Krebs buffer, and loaded with fluo-4. Spontaneous and nerve stimulation-evoked calcium transients were recorded and, following calcium imaging, some EOMs were double-labeled with rhodamine-conjugated alpha-bungarotoxin (rhBTX) to identify EOM myofiber types. EOMs showed two main types of spontaneous calcium transients, one slow type (calcium waves with 1/2(max) duration of 2-12 s, velocity of 25-50 µm/s) and two fast "flash-like" types (Type 1, 30-90 ms; Type 2, 90-150 ms 1/2(max) duration). Single pulse nerve stimulation evoked fast calcium transients identical to the fast (Type 1) calcium transients. Calcium waves were accompanied by a local myofiber contraction that followed the calcium transient wavefront. The magnitude of calcium-wave induced myofiber contraction far exceeded those of movement induced by nerve stimulation and associated fast calcium transients. Tetrodotoxin eliminated nerve-evoked transients, but not spontaneous transients. Alpha-bungarotoxin eliminated both spontaneous and nerve-evoked fast calcium transients, but not calcium waves, and caffeine increased wave activity. Calcium waves were observed in myofibers lacking spontaneous or evoked fast transients, suggestive of multiply-innervated myofibers, and this was confirmed by double-labeling with rhBTX. We propose that the abundant spontaneous calcium transients and calcium waves with localized contractions that do not depend on innervation may contribute to intrinsic generation of tonic functions of EOMs.