Foramen magnum meningiomas

The foramen magnum meningioma (FMM) is one of most challenging tumors among all the meningiomas because of its distinctive location, clinical course, insidious onset, and the relative large size of the tumor during presentation. These tumors are slow-growing and clinical symptoms vary according to involvement of different structures including the spinal cord, vertebral artery, lower cranial nerves, and medulla oblongata. Controversies regarding appropriate surgical approach for resection of tumor in this unique location continue. Tumors in the posterior or posterolateral region of the foramen magnum is accessible by midline suboccipital approach. The anterior and anterolateral tumors are encountered by various modifications of the far lateral approach. Drilling of condylar fossa is adequate in most of the cases as tumors often create a surgical corridor. However, an anterior tumor with significant extension on both sides of midline may require variable amounts of condyle resection. Here we review the FMMs with an emphasis on surgical approaches.

The Relationship Between Obstructive Sleep Apnea and Ruptured Intracranial Aneurysms

STUDY OBJECTIVES

The role of obstructive sleep apnea (OSA) in the overall outcome of ruptured intracranial aneurysms (RIAs) is unknown. We have investigated the role of OSA in overall outcome of RIAs.

METHODS

Data from 159 consecutive patients were retrospectively reviewed. A chi-square test and regression analysis were performed to determine the significant difference. A value of P < .05 was considered significant.

RESULTS

The prevalence of OSA in RIAs was fivefold higher in the nonaneurysm patient group, P = .002. The number of patients with hypertension (P < .0001), body mass index ≥ 30 (P < .0001), hyperlipidemia (P = .018), chronic heart disease (P = .002) or prior ischemic stroke (P = .001) was significantly higher in the OSA group. Similarly, the number of wide-neck aneurysms (P < .0001) and aneurysm > 7 mm (P = .004), poor Hunt and Hess grade IV-V (P = .005), vasospasms, (P = .03), and patients with poor Modified Rankin Scale scores (3-6) was significantly higher in the OSA group (P < .0001). Interestingly, for the first time in univariate (P = .01) and multivariate (P = .003) regression analysis, OSA was identified as an individual predictor of unfavorable outcome of RIAs. In addition, hypertension (P = .04), smoking (P = .049), chronic heart disease (P = .01), and Hunt and Hess grade IV-V (P = .04) were revealed as predictors of poor outcome of RIAs.

CONCLUSIONS

This is a novel study to determine the association between OSA and ruptured cerebral aneurysm in terms of comorbidities, size of aneurysm, severity of symptoms, and outcomes after treatment. In addition, for the first time, OSA is identified as a positive predictor of unfavorable outcome of RIAs.

Deep brain stimulation of the cerebellum for poststroke motor rehabilitation: from laboratory to clinical trial

Ischemic stroke is a leading cause of disability worldwide, with profound economic costs. Poststroke motor impairment is the most commonly encountered deficit resulting in significant disability and is the primary driver of stroke-associated healthcare expenditures. Although many patients derive some degree of benefit from physical rehabilitation, a significant proportion continue to suffer from persistent motor impairment. Noninvasive brain stimulation, vagal nerve stimulation, epidural cortical stimulation, and deep brain stimulation (DBS) have all been studied as potential modalities to improve upon the benefits derived from physical therapy alone. These neuromodulatory therapies aim primarily to augment neuroplasticity and drive functional reorganization of the surviving perilesional cortex. The authors have proposed a novel and emerging therapeutic approach based on cerebellar DBS targeted at the dentate nucleus. Their rationale is based on the extensive reciprocal connectivity between the dentate nucleus and wide swaths of cerebral cortex via the dentatothalamocortical and corticopontocerebellar tracts, as well as the known limitations to motor rehabilitation imposed by crossed cerebellar diaschisis. Preclinical studies in rodent models of ischemic stroke have shown that cerebellar DBS promotes functional recovery in a frequency-dependent manner, with the most substantial benefits of the therapy noted at 30-Hz stimulation. The improvements in motor function are paralleled by increased expression of markers of synaptic plasticity, synaptogenesis, and neurogenesis in the perilesional cortex. Given the findings of preclinical studies, a first-in-human trial, Electrical Stimulation of the Dentate Nucleus Area (EDEN) for Improvement of Upper Extremity Hemiparesis Due to Ischemic Stroke: A Safety and Feasibility Study, commenced in 2016. Although the existing preclinical evidence is promising, the results of this Phase I trial and subsequent clinical trials will be necessary to determine the future applicability of this therapy.

Resection of posterior clinoid meningioma through retrosigmoid approach: concepts and nuances

Meningiomas arising from the posterior clinoid process pose a great surgical challenge because of their location and propensity to cause critical neurovascular compression. The authors' patient was a 66-year-old female who had a large posterior clinoid meningioma with significant brainstem compression that was operated on through the retrosigmoid approach. This 3D surgical video emphasizes the various technical concepts that are important to preserving compressed neural and vascular structures during the surgery. It would also be interesting to note the extent of visualization around the posterior clinoid region gained through a retrosigmoid corridor. The video can be found here: https://youtu.be/CBmT_0ov0YA .

Correction: A spiropyran-coumarin platform: an environment sensitive photoresponsive drug delivery system for efficient cancer therapy

Correction for 'A spiropyran-coumarin platform: an environment sensitive photoresponsive drug delivery system for efficient cancer therapy' by Shrabani Barman et al., J. Mater. Chem. B, 2017, DOI: 10.1039/c7tb00379j.

Do the clinicoradiological outcomes of endoscopic fenestration for intracranial cysts count on age? An institutional experience

BACKGROUND

The clinicoradiological outcome of endoscopic fenestration of intracranial cysts and predictors of an unfavorable outcome, including age, are under reported in the neurosurgical literature. In this cohort, our experience in the endoscopic fenestration of intracranial cysts is reviewed.

MATERIALS AND METHODS

Thirty consecutive patients treated with endoscopic fenestration for intracranial cysts were identified and analyzed. The study population in our series was followed clinically and radiographically.

RESULTS

In this series, the overall resolution of clinical symptoms such as headache, seizures, and neurological deficits was 83%, P= 0.0001. The percentage of clinical resolution after endoscopic intervention was significantly higher (85% vs. 76%, P= 0.001) in arachnoid cysts compared to other cyst types. The reduction of arachnoid cyst size was significantly higher in adults with obstructive hydrocephalus compared to the children group (P = 0.037). In addition, requirement of a cystoperitoneal shunt placement (P = 0.0001) and its subsequent revision (P = 0.0001) was significantly lower in adults compared to children. Adults (P = 0.041), presence of an arachnoid cyst (P = 0.026), female gender (P = 0.016), and presence of communicative hydrocephalus (P = 0.015) were significant predictors for improvement in the symptoms of intracranial pressure. Lastly, adults (P = 0.028), presence of arachnoid cyst (P = 0.046), and presence of communicative hydrocephalus (P = 0.012) were significant positive predictors for shunt revision.

CONCLUSIONS

This study revealed that endoscopic fenestration is an effective neurosurgical procedure for the management of intracranial cysts both in adults and children. Moreover, endoscopic fenestration is more beneficial in adults and patients with an arachnoid cyst compared to that in children and other cyst types, respectively.

Epidemiology of adult-onset hydrocephalus: institutional experience with 2001 patients

OBJECTIVE Adult-onset hydrocephalus is not commonly discussed in the literature, especially regarding its demographic distribution. In contrast to pediatric hydrocephalus, which is related to a primary CSF pathway defect, its development in adults is often secondary to other pathologies. In this study, the authors investigated the epidemiology of adult-onset hydrocephalus as it pertains to different etiologies and in reference to age, sex, and race distributions. METHODS The authors retrospectively reviewed the clinical notes of 2001 patients with adult-onset hydrocephalus who presented to Louisiana State University Health Sciences Center within a 25-year span. Significant differences between the groups were analyzed by a chi-square test; p < 0.05 was considered significant. RESULTS The overall mean (± SEM) incidence of adult hydrocephalus in this population was 77 ± 30 per year, with a significant increase in incidence in the past decade (55 ± 3 [1990-2003] vs 102 ± 6 [2004-2015]; p < 0.0001). Hydrocephalus in a majority of the patients had a vascular etiology (45.5%) or was a result of a tumor (30.2%). The incidence of hydrocephalus in different age groups varied according to various pathologies. The incidence was significantly higher in males with normal-pressure hydrocephalus (p = 0.03) or head injury (p = 0.01) and higher in females with pseudotumor cerebri (p < 0.0001). In addition, the overall incidence of hydrocephalus was significantly higher in Caucasian patients (p = 0.0002) than in those of any other race. CONCLUSIONS Knowledge of the demographic variations in adult-onset hydrocephalus is helpful in achieving better risk stratification and better managing the disease in patients. For general applicability, these results should be validated in a large-scale meta-analysis based on a national population database.

A systematic review of overall survival in pediatric primary glioblastoma multiforme of the spinal cord

OBJECTIVE The incidence of primary spinal cord glioblastoma multiforme (GBM) in the pediatric age group is very rare. Only a few case series and case reports have been published in the literature; therefore, overall survival (OS) outcome and the as-yet poorly defined management options are not discussed in detail. The authors performed a cumulative survival analysis of all reported cases of pediatric spinal cord GBM to identify the predictive factors related to final survival outcome. METHODS A comprehensive search for relevant articles was performed on PubMed's electronic database MEDLINE for the period from 1950 to 2015 using the search words "malignant spinal cord tumor" and "spinal glioblastoma multiforme." This study was limited to patients younger than 18 years of age. Survival rates for children with various tumor locations and treatments were collected from the published articles and analyzed. RESULTS After an extensive literature search, 29 articles met the study inclusion criteria. From the detailed information in these articles, the authors found 53 children eligible for the survival analysis. The majority (45%) of the children were more than 12 years old. Thirty-four percent of the cases were between 7 and 12 years of age, and 21% were younger than 7 years. In the Kaplan-Meier survival analysis, children younger than 7 years of age had better survival (13 months) than the children older than 7 years (7-12 years: 10 months, > 12 years: 9 months; p = 0.01, log-rank test). Fifty-five percent of the children were female and 45% were male. A cervical tumor location (32%) was the most common, followed by thoracic (28.3%). Cervicothoracic (18.9%) and conus (18.8%) tumor locations shared the same percentage of cases. Cervical tumors had a worse outcome than tumors in other locations (p = 0.003, log-rank test). The most common presenting symptom was limb weakness (53%), followed by sensory disturbances (25%). Median OS was 10 months. The addition of adjuvant therapy (radiotherapy [RT] and/or chemotherapy [CT]) after surgery significantly improved OS (p = 0.01, log-rank test). Children who underwent gross-total resection and RT had better outcomes than those who underwent subtotal resection and RT (p = 0.04, log-rank test). Cerebrospinal fluid spread, hydrocephalus, brain metastasis, and spinal metastasis were not correlated with OS in primary spinal GBM. CONCLUSIONS Adjuvant therapy after surgery had a beneficial effect on overall outcome of spinal GBM in the pediatric age group. Gross-total resection followed by RT produced a better outcome than subtotal resection with RT. Further large-scale prospective study is required to establish the genetic and molecular factors related to OS in primary GBM of the spinal cord in pediatric patients.

Microsurgical Clipping of Unruptured Intracranial Aneurysms: A Single Surgeon's Experience over 16 Years

BACKGROUND

Unruptured intracranial aneurysms (UIAs) have become an issue of greater significance as their detection rates have increased over the years. We present the overall experience of microsurgical clipping of unruptured aneurysms by a single surgeon over a period of more than 16 years.

METHODS

The clinical and radiologic data were reviewed retrospectively. Clinical outcome at follow-up was assessed with Glasgow Outcome Scale, and angiograms were reviewed for the degree of occlusion.

RESULTS

One hundred ninety-six patients with 221 UIAs were included in the analysis. The median age of patients was 54 years, with a female preponderance. Eighty-two percent of the patients had chronic headache on presentation. Middle cerebral artery aneurysms (32.2%) and posterior-inferior-cerebellar-artery aneurysms (46.1%) were most common in the anterior and posterior circulation, respectively. The perioperative complication rate was 17.3%. The overall surgical morbidity and mortality were 2.1% and 1.5%, respectively. With median follow-up of 11.3 months, 82% of patients were almost asymptomatic with a complete occlusion rate of 94%. The proportion of UIAs being coiled has significantly increased in the last decade, with a concomitant increase in the risk of poor clinical outcome after surgery.

CONCLUSION

Surgical clipping is effective and can provide a good long-term outcome. The most commendable consequence that it provides is a better long-term occlusion rate. The experience of the individual surgeon is important for a superior and enduring overall outcome. An increase in the rate of coiling in recent years has affected the outcome rate after surgery that calls for further evaluation.

Spinal subarachnoid hemorrhage and aneurysms

Spinal subarachnoid hemorrhage (SAH) is a rare disease. Spinal aneurysms are even rarer and mostly undetected unless they rupture and become symptomatic. In this chapter we aim to review the available literature about spinal subarachnoid hematoma with special emphasis on spinal aneurysms. As most reports of spinal aneurysms describe a single case or a small case series, the diagnostic algorithm is often lacking. The outcome is also different based on the etiologies; therefore management strategy must be individualized. We addressed these issues in this chapter. The reported incidence of spinal SAH is less than epidural hematoma and more than subdural hematoma. Spinal aneurysms can present as isolated entity or can be associated with other vascular anomalies. Microsurgical clipping and/or resection is possible, especially when they are located dorsally or dorsolaterally. Endovascular approach is also a feasible option unless negotiation of microcatheter becomes difficult in tortuous small-caliber arteries. Successful obliteration leads to good outcome, especially when present in posterior spinal artery. A detailed knowledge of spinal SAH and spinal aneurysms is important to detect them in time. Clinicians must consider several factors to choose an appropriate treatment strategy to ensure the safety of their patients.

Role of radiological parameters in predicting overall shunt outcome after ventriculoperitoneal shunt insertion in pediatric patients with obstructive hydrocephalus

OBJECTIVE

Despite significant advances in the medical field and shunt technology, shunt malfunction remains a nightmare of pediatric neurosurgeons. In this setting, the ability to preoperatively predict the probability of shunt malfunction is quite compelling. The authors have compared the preoperative radiological findings in obstructive hydrocephalus and the subsequent clinical course of the patient to determine any association with overall shunt outcome.

METHODS

This retrospective study included all pediatric patients (age < 18 years) who had undergone ventriculoperitoneal shunt insertion for obstructive hydrocephalus. Linear measurements were taken from pre- and postoperative CT or MRI studies to calculate different indices and ratios including Evans' index, frontal horn index (FHI), occipital horn index (OHI), frontooccipital horn ratio (FOHR), and frontooccipital horn index ratio (FOIR). Other morphological features such as bi- or triventriculomegaly, right-left ventricular symmetry, and periventricular lucency (PVL) were also noted. The primary clinical outcomes that were reviewed included the need for shunt revision, time interval to first shunt revision, frequency of shunt revisions, and revision-free survival.

RESULTS

A total of 121 patients were eligible for the analysis. Nearly half of the patients (47.9%) required shunt revision. The presence of PVL was associated with lower revision rates than those in others (39.4% vs 58.2%, p = 0.03). None of the preoperative radiological indices or ratios showed any correlation with shunt revision. Nearly half of the patients with shunt revision required early revision (< 90 days of primary surgery). The reduction in the FOHR was high in patients who required early shunt revision (20.16% in patients with early shunt revision vs 6.4% in patients with late shunt revision, p = 0.009). Nearly half of the patients (48.3%) requiring shunt revision ultimately needed more than one revision procedure. Greater occipital horn dilation on preoperative images was associated with a lower frequency of shunt revision, as dictated by a high OHI and a low FOIR in patients with a single shunt revision as compared with those in patients who required multiple shunt revisions (p = 0.029 and 0.009, respectively). The mean follow-up was 49.9 months. Age was a significant factor affecting shunt revision–free survival. Patients younger than 6 months of age had significantly less revision-free survival than the patients older than 6 months (median survival of 10.1 vs 94.1 months, p = 0.004).

CONCLUSIONS

Preoperative radiological linear indices and ratios do not predict the likelihood of subsequent shunt malfunction. However, patients who required early shunt revision tended to have greater reductions in ventricular volumes on postoperative images. Therefore a greater reduction in ventricular volume is not actually desirable, and a ventricular volume high enough to reduce intracranial pressure is instead to be aimed at for long-term shunt compliance.

Spinal meningiomas: clinicoradiological factors predicting recurrence and functional outcome

OBJECTIVE

Spinal meningiomas are benign tumors with a wide spectrum of clinical and radiological features at presentation. The authors analyzed multiple clinicoradiological factors to predict recurrence and functional outcome in a cohort with a mean follow-up of more than 4 years. The authors also discuss the results of clinical studies regarding spinal meningiomas in the last 15 years.

METHODS

The authors retrospectively reviewed the clinical and radiological details of patients who underwent surgery for spinal tumors between 2001 and 2015 that were histopathologically confirmed as meningiomas. Demographic parameters, such as age, sex, race, and association with neurofibromatosis Type 2, were considered. Radiological parameters, such as tumor size, signal changes of spinal cord, spinal level, number of levels, location of tumor attachment, shape of tumor, and presence of dural tail/calcification, were noted. These factors were analyzed to predict recurrence and functional outcome. Furthermore, a pooled analysis was performed from 13 reports of spinal meningiomas in the last 15 years.

RESULTS

A total of 38 patients were included in this study. Male sex and tumors with radiological evidence of a dural tail were associated with an increased risk of recurrence at a mean follow-up of 51.2 months. Ventral or ventrolateral location, large tumors, T2 cord signal changes, and poor preoperative functional status were associated with poor functional outcome at 1-year follow-up.

CONCLUSIONS

Spine surgeons must be aware of the natural history and risk factors of spinal meningiomas to establish a prognosis for their patients.

Intra-operative micro-electrode recording in functional neurosurgery: Past, present, future

The field of functional neurosurgery has experienced a rise, fall and lastly a renaissance over the past 75years. Micro-electrode recording (MER) played a key role during this eventful journey. However, as the intra-operative MRI continues to evolve, a pertinent question about the utility of MER has been raised in recent years. In this article, we critically review these current controversies. The English literature is reviewed and the complex technique of MER is discussed in a simplified manner. The improvement of neuroimaging and its application in functional neurosurgery, especially in deep brain stimulation, is discussed. Finally, the current controversies and technical advances which can direct the future are reviewed. The results of existing meta-analyses addressing the controversies are summarized. Wide variations of pre-operative and intra-operative targeting methods have been described in the literature. Though functional neurosurgery is generally safe, complications do occur and multiple passes during MER can certainly add to the risk of inadvertent hemorrhage and infection. Additionally, the recent introduction of newer MRI modalities has ensured better delineation of the target. However, MER is still useful to address brain shift, for mapping of newer targets, for ablative surgeries and in centers without an intra-operative imaging facility. In the current scenario, it is nearly impossible to conduct a prospective study to decide the utility of MER. The importance of MER may further diminish in the future as a routine procedure, but its role as a gold standard procedure may still persist.

Evaluation of Ventriculoperitoneal Shunt-Related Complications in Intracranial Meningioma with Hydrocephalus

Objective Meningioma is a common intracranial tumor that predisposes patients to hydrocephalus which may require a permanent cerebrospinal fluid (CSF) diversion procedure such as ventriculoperitoneal (VP) shunts. We reviewed our long-term experience with VP shunts for the management of hydrocephalus in patients with meningioma. Methods and Materials A total of 48 Patients with meningioma who underwent VP shunt insertion for hydrocephalus from 1990 to 2013 was included in our case series. The study population was evaluated clinically and radiographically after VP shunt placement. Results Overall shunt failure was seen in 13 (27%) patients. Single and multiple shunt revisions were required in eight (16.7%) and five (10.4%) patients, respectively. The overall shunt revision within 6 months, 1 , and 5 years was 19, 23, and 27%, respectively. Male patient was significantly associated with the longer survival after shunt placement. Revisions free survival after 3, 5, 10, and 15 years of VP shunt placement were 70, 46, 30, and 20%, respectively. Finally, in regression analysis, age greater than 65 years (p = 0.02, 95% confidence interval (CI) = 0.1-0.13), tumor in posterior fossa (p < 0.0001, 95% CI = 0.1-0.23), tumor size (> 5 cm) (p = 0.3, 95% CI = 0.01-0.19), and Simpson resection grades II to IV (p = 0.04, 95% CI = 0.07-0.2) were identified as positive predictors of requirement of CSF flow diversion Conclusion The findings of the present study reveal that VP shunting is an important treatment option for the management of hydrocephalus in patients with meningioma. Further studies using less invasive techniques are warranted to compare the benefits of VP shunt for the management of hydrocephalus.

Tailor-Made Temperature-Sensitive Micelle for Targeted and On-Demand Release of Anticancer Drugs

The design of nanomedicines from the tuned architecture polymer is a leading object of immense research in recent years. Here, smart thermoresponsive micelles were prepared from novel architecture four-arm star block copolymers, namely, pentaerythritol polycaprolactone-b-poly(N-isopropylacrylamide) and pentaerythritol polycaprolactone-b-poly(N-vinylcaprolactam). The polymers were synthesized and tagged with folic acid (FA) to render them as efficient cancer cell targeting cargos. FA-conjugated block copolymers were self-assembled to a nearly spherical (ranging from 15 to 170 nm) polymeric micelle (FA-PM) with a sufficiently lower range of critical micelle concentration (0.59 × 10(-2) to 1.52 × 10(-2) mg/mL) suitable for performing as an efficient drug carrier. The blocks show lower critical solution temperature (LCST) ranging from 30 to 39 °C with high DOX-loading content (24.3%, w/w) as compared to that reported for a linear polymer in the contemporary literature. The temperature-induced reduction in size (57%) of the FA-PM enables a high rate of DOX release (78.57% after 24 h) at a temperature above LCST. The DOX release rate has also been tuned by on-demand administration of temperature. The in vitro biocompatibilities of the blank and DOX-loaded FA-PMs have been studied by the MTT assay. The cellular uptake study proves selective internalization of the FA-PM into cancerous cells (C6 glioma) compared that into normal cells (HaCaT). In vivo administration of the DOX-loaded FA-PMs into the C6 glioma rat tumor model resulted in significant accumulation in tumor sites, which drastically inhibited the tumor volume by ∼83.9% with respect to control without any significant systemic toxicity.

Relevance of Simpson grading system and recurrence-free survival after surgery for World Health Organization Grade I meningioma

OBJECTIVE The clinical significance of the Simpson system for grading the extent of meningioma resection and its role as a predictor of the recurrence of World Health Organization (WHO) Grade I meningiomas have been questioned in the past, echoing changes in meningioma surgery over the years. The authors reviewed their experience in resecting WHO Grade I meningiomas and assessed the association between extent of resection, as evaluated using the Simpson classification, and recurrence-free survival (RFS) of patients after meningioma surgery. METHODS Clinical and radiological information for patients with WHO Grade I meningiomas who had undergone resective surgery over the past 20 years was retrospectively reviewed. Simpson and Shinshu grading scales were used to evaluate the extent of resection. Statistical analysis was conducted using Kaplan-Meier curves and Cox proportional-hazards regression. RESULTS Four hundred fifty-eight patients were eligible for analysis. Overall tumor recurrence rates for Simpson resection Grades I, II, III, and IV were 5%, 22%, 31%, and 35%, respectively. After Cox regression analysis, Simpson Grade I (extensive resection) was revealed as a significant predictor of RFS (p = 0.003). Patients undergoing Simpson Grade I and II resections showed significant improvement in RFS compared with patients undergoing Grade III and IV resections (p = 0.005). Extent of resection had a significant effect on recurrence rates for both skull base (p = 0.047) and convexity (p = 0.012) meningiomas. Female sex and a Karnofsky Performance Scale score > 70 were also identified as independent predictors of RFS after resection of WHO Grade I meningioma. CONCLUSIONS In this patient cohort, a significant association was noted between extent of resection and rates of tumor recurrence. In the authors' experience the Simpson grading system maintains its relevance and prognostic value and can serve an important role for patient education. Even though complete tumor resection is the goal, surgery should be tailored to each patient according to the risks and surgical morbidity.

Isadore Max Tarlov (1905–1977) and the controversial Tarlov cyst: historical perspective

Isadore Max Tarlov, an early neurosurgeon, made several important contributions to the field of spine surgery. He described sacral perineural cysts, now known as Tarlov cysts. Dr. Tarlov also introduced the knee-chest patient position to facilitate exposure and hemostasis in lumbar surgery. In addition, he developed the use of fibrin glue in nerve repair. His book on mechanisms of spinal compression was published in 1957. He published a book of essays titled Principles of Parsimony in Medical Practice that remains highly relevant in today's medical world.

Surgical Outcomes and Predictors of Recurrence in Elderly Patients with Meningiomas

BACKGROUND

Meningiomas are more prevalent with increasing age, and there is no general consensus of surgical management for this group of tumors. The role of resection and the predictors of recurrence of meningiomas in elderly patients have not been well established. The authors reviewed their experience of surgical resection of these tumors in elderly patients and determined the factors for recurrence.

METHODS

Clinical and radiologic information of 81 elderly patients with meningiomas was retrospectively reviewed. Simpson grading scales were used to evaluate the extent of surgical resection. Statistical analysis was conducted using Kaplan-Meier curves and Cox proportional hazards regression.

RESULTS

In this study, the recurrence rate in the grades I-II resection group was 10%, whereas in the grades III-IV resection group, the recurrence rate was 46% (P < 0.001). In Cox regression analysis, Simpson grades I-II/complete resection was revealed as a significant predictor of recurrence-free survival (P = 0.002). The hazard ratio for recurrence after grades III-IV resection was 5 times higher than after grades I-II resection. Location, size of the tumor, medical comorbidities, Karnofsky Performance Status, Geriatric Scoring System (GSS) score >16, and repeated resection were identified as predictors of recurrence-free survival after resection of meningiomas.

CONCLUSIONS

Elderly patients with meningiomas having a GSS score >16 and undergoing Simpson grades I-II/gross total resection have low operative morbidity, mortality, and recurrence rates and are less likely to continue on antiepileptic medications. Although complete tumor resection is the goal, the surgical approach should be tailored to each patient depending on the patient's GSS score.

Utility of Neuronavigation in Intracranial Meningioma Resection: A Single-Center Retrospective Study

OBJECTIVE

In this study, we validate the utility of navigation in intracranial meningioma excision and evaluate the effectiveness of image guidance surgery based on clinical outcome, extent of resection, and recurrence-free survival (RFS).

METHODS

Information related to clinical history, use of neuronavigation, neuroimaging, microsurgical dissection, and outcomes of 517 consecutive cases with meningiomas between January 1995 and June 2015 was collected retrospectively. A Cox proportional hazards regression model was used to determine independent predictors of RFS.

RESULTS

In this study, overall recurrence rate after tumor excision with or without neuronavigation was 17.7% and 31.2%, respectively (P = 0.03). Based on neuronavigation use, RFS of the patients with meningiomas in different locations also varied significantly (skull base; with, 110 months vs. without, 157 months; P = 0.02). The median RFS for patients operated on with or without use of neuronavigation during resection of tumors was 167 and 97 months, respectively, (log-rank P =0.0001). In Cox regression multivariate analysis, use of neuronavigation (P = 0.0001), gross total resection (Simpson grade I-II; P = 0.001), and World Health Organization grade I tumor (P = 0.0001) were revealed as significant predictors of RFS. In addition, mean blood loss (P = 0.005) and average length of stay (P = 0.008) in the hospital were significantly reduced and performance status was improved using neuronavigation during resection of meningiomas.

CONCLUSIONS

Interactive surgical navigation is a useful tool in the operative management of intracranial meningiomas to decrease recurrence rate, blood loss, and length of stay, and to improve RFS and performance status. Therefore, use of neuronavigation should be ensured during resection of intracranial meningiomas.

A series of enterococcal brain abscesses

Background:

Neurosurgeons in developing countries come across brain abscess frequently, but Enterococcus as a cause of abscess is rare.

Aims:

To describe clinical profile and treatment of a series of patients with enterococcal brain abscess.

Materials and Methods:

We retrospectively reviewed microbiological records of patients with brain abscess to identify Enterococcus as a causative organism.

Results:

12 patients (nine males) were diagnosed to have enterococcal brain abscess. All were due to E. species.

Conclusions:

The clinical feature and management are not different from other etiological agents. The prognosis of enterococcal brain abscess is more favourable than bacteremia.

Rosai-Dorfman disease presenting as cervical extradural lesion: a case report with review of literature

Sinus histiocytosis with massive lymphadenopathy or Rosai-Dorfman disease is a rare, but well documented entity. We report a lady who presented with progressive quadriparesis, with cervical extradural lesion on magnetic resonance imaging. She underwent decompression of the lesion and histological diagnosis of the lesion was Rosai-Dorfman disease. On one-year follow-up, she had complete improvement of the deficits with no further progression of the lesion. The presentation of this disease as an isolated spinal extradural mass lesion is quite rare, with only six cases reported in literature.

Teratoma in split cord malformation: an unusual association: a report of two cases with a review of the literature

Split cord malformations (SCM) may be discovered as isolated occult spinal dysraphism or in association with various other overt developmental spinal abnormalities or lesions. However, the occurrence of SCM with intraspinal teratoma is rare. We report 2 cases of teratoma associated with SCM, of which one is intramedullary and the other extradural within meningocele, with a brief review of the literature.

Bio-functionalization of magnetite nanoparticles using an aminophosphonic acid coupling agent: new, ultradispersed, iron-oxide folate nanoconjugates for cancer-specific targeting

The present study describes a systematic approach towards the design and development of novel, bio-functionalized, magneto-fluorescent nanoparticles for cancer-specific targeting. Biocompatible, hydrophilic, magneto-fluorescent nanoparticles with surface-pendant amine, carboxyl or aldehyde groups, to be later used for bio-conjugation, were designed using an aminophosphonic acid coupling agent. These magneto-fluorescent nanoparticles were further functionalized with folic acid, using diverse conjugation strategies. A series of new iron-oxide folate nanoconjugates with excellent aqueous dispersion stability and reasonably good hydrodynamic sizes under a wide range of physiological conditions were developed. These ultradispersed nanosystems were analyzed for their physicochemical properties and cancer-cell targeting ability, facilitated by surface modification with folic acid. The nanoparticle size, charge, surface chemistry, magnetic properties and colloidal stability were extensively studied using a variety of complementary techniques. Confocal microscopy, performed with folate receptor positive human cervical HeLa cancer cells, established that these non-cytotoxic iron-oxide folate nanoconjugates were effectively internalized by the target cells through receptor-mediated endocytosis. Cell-uptake behaviors of nanoparticles, studied using magnetically activated cell sorting (MACS), clearly demonstrated that cells over-expressing the human folate receptor internalized a higher level of these nanoparticle-folate conjugates than negative control cells.

Transient expression, purification and characterization of bioactive human fibroblast growth factor 8b in tobacco plants

cDNA of human fibroblast growth factor 8 isoform b (FGF8b) was cloned for the first time into a plant expression vector with or without endoplasmic reticulum retention signal (KDEL) and was transiently expressed as His tagged fusion protein in Nicotiana tabacum leaves through Agrobacterium mediated gene transfer by vacuum infiltration method. Expression of FGF8b was confirmed by ELISA and Western blot using anti-FGF8b antibody and the expression level was measured as 4.1% of total soluble protein of tobacco leaves. The expressed recombinant protein was purified by Ni-NTA affinity chromatography and its molecular weight was determined by MALDI-TOF-MS. Schiff's test, Concanavalin A (Con A) immunoblot and enzymatic deglycosylation indicated that the high molecular mass was due to glycosylation of the FGF8b expressed in plant cells. Measurement of its biological activity in NIH3T3 cells by thymidine incorporation and MTT assay showed induction of cell proliferation. These results indicate that biologically active recombinant FGF8b could be expressed in tobacco plants.

Biocompatibility of diamond-like nanocomposite thin films

Diamond-like nanocomposite (DLN) films consist of network structure of amorphous carbon and quartz like silicon. In the present work, DLN films have been synthesized on pyrex glass and subsequently, their biocompatibility have been investigated through primary and secondary cell adhesion, cytotoxicity, protein adsorption and murine peritoneal macrophage activation experiments. Variable degree of cell and protein response have been found based on variable film synthesis parameters but in overall, required biocompatibility has been established for all types of film-coating.

Adjuvant effect of mushroom glucan and bovine lactoferrin upon Aeromonas hydrophila vaccination in catla, Catla catla (Hamilton)

Mushroom glucan and bovine lactoferrin (Lf), known for their immunostimulatory potential, were used as adjuvant in conjunction with a formalin-killed Aeromonas hydrophila vaccine in catla, Catla catla. In vitro antigen-specific responsiveness of catla leucocytes and protective responses against experimental challenge with homologous antigen were monitored following immunization. Antigen-specific proliferation, 'macrophage activating factor' (MAF) production and antibody production were significantly higher in fish injected with glucan adjuvanted vaccine. Lf adjuvanted preparations showed a weak proliferative response and MAF production, although the antibody production was significantly higher than the controls. A good degree of protection was achieved with the glucan adjuvanted vaccine. However, in spite of producing significant anti-A. hydrophila antibody, Lf adjuvanted vaccine did not confer any protection following challenge with A. hydrophila. The potential of adjuvanticity of mushroom glucan and bovine Lf in intraperitoneal vaccination is discussed.

CD4+ T-cell responses to recombinant hsp65 and hsp18 of M. leprae and their trypsin-digested fragments in leprosy: diversity in HLA-DR restriction

Mycobacterium leprae heat-shock proteins hsp65 and hsp18 have received immense attention as major T-cell target antigens in leprosy. Both of these hsps and their tryptic fragments were characterized for their ability to stimulate CD4+ T cells derived from polar leprosy cases and healthy contacts. The optimal digestion of hsps with trypsin yielded four fragments of hsp65--TDB65-1 (24 kDa), TDB65-2 (18 kDa), TDB65-3 (17 kDa), TDB65-4 (14 kDa)-- and three of hsp18--TDB18-1 (10 kDa), TDB18-2 (5 kDa), TDB18-3 (3 kDa). While all of these tryptic fragments and undigested hsps triggered CD4+ T cells from tuberculoid (TT) leprosy patients and healthy contacts (SI > 2), only two fragments--TDB65-2 and TDB18-3--were found to be stimulatory in anergic lepromatous (LL) leprosy patients (SI = 5.27 and 3.0, respectively). Blocking studies using allele-specific anti-DR monoclonal antibodies revealed multiple HLA-Dr restriction, with DR2 providing the strongest restriction in both TT as well as LL leprosy. These findings indicate that M. leprae hsps and their trypsin-digested fragments are promiscuous and recognizable in the context of diverse HLA alleles, of which DR2 is the most efficient restriction element. The 18-kDa fragment of hsp65 and the 3-kDa fragment of hsp18 are the most versatile fragments that could elicit in vitro proliferation in both polar forms of leprosy.

Microbial production of L-tyrosine: a review

Microbial production of L-tyrosine by direct fermentation and by enzymatic methods has been reviewed. Achievements in this regard made through recombinant DNA techniques have also been included. The review also includes biosynthesis and regulation of tyrosine.

Production of some extracellular enzymes by a lignin peroxidase-producing brown rot fungus, Polyporus ostreiformis, and its comparative abilities for lignin degradation and dye decolorization

Polyporus ostreiformis produced Mn peroxidase, acid protease, alpha-amylase, and lignin peroxidase, with maximum activities of 40, 8,300, and 4,200 U liter-1 and 50 nkat liter-1, respectively, in nitrogen-limited liquid media. The fungus removed only 18.6% lignin from rice straw in 3 weeks but effected 99% decolorization of Congo red dye in 9 days.

L-phenylalanine production by double auxotrophic mutants of Arthrobacter globiformis

A number of tryptophan-plus-tyrosine double auxotrophs have been isolated from a glutamate producing Arthrobacter globiformis excreting L-phenylalanine by two-step mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine. For the three potent mutants tested the medium of Alföldi was found to be the best. The optimum tryptophan, tyrosine and biotin concentrations for phenylalanine production of these mutants were 0.5 mmol/L, 0.1 mmol/L and 5 micrograms/L, respectively. At these levels strain TT-39 yielded 2.6 g phenylalanine per L of medium in flask culture with glucose (350 mmol/L) and NH4Cl (60 mmol/L).

Purification and characterization of three toxins and two agglutinins from Abrus precatorius seed by using lactamyl-Sepharose affinity chromatography

Three toxins, abrin-I, -II, and -III, and two agglutinins, APA-I and -II, were purified from the seeds of Abrus precatorius by lactamyl-Sepharose affinity chromatography followed by gel filtration and DEAE-Sephacel column chromatography. Abrin-I did not bind on DEAE-Sephacel column chromatography and the bound abrin-II, abrin-III, APA-I, and APA-II were eluted with a sodium acetate gradient. The identity of each protein was established by sodium dodecylsulfate-polyacrylamide gel electrophoresis and isoelectric focusing. The relative molecular weights are abrin-I, 64,000; abrin-II and abrin-III, 63,000 each: APA-I, 130,000; and APA-II, 128,000. Isoelectric focusing revealed microheterogeneity due to the presence of isoforms in each protein. Toxicity and binding studies further confirmed the differences among the lectins. The time course of inhibition of protein synthesis in thymocytes by the toxins showed lag times of 78, 61, and 72 min with Ki's of 0.55, 0.99, and 0.74 ms-1 at a 0.63 nM concentration of each of abrin-I, -II, and -III, respectively. A Scatchard plot obtained from the equilibrium measurement for the lectins binding to lactamyl-Sepharose beads showed nonlinearity, indicating a cooperative mode of binding which was not observed for APA-I binding to Sepharose 4B beads. Further, by the criterion of the isoelectric focusing profile, it was shown that the least toxic abrin-I and the highly toxic abrin-II isolated by lactamyl-Sepharose chromatography were not retained on a low-affinity Sepharose 4B matrix, which signifies the necessity of using a high-affinity matrix for the purification of the lectins.

Microbial production of L-tryptophan: a review

Microbial production of L-tryptophan has been reviewed with 172 references. The review includes different tryptophan producing microorganisms, their optimal cultural conditions, yields, assay and process of recovery. It also includes a discussion on the pathway of tryptophan biosynthesis and its regulation. Achievements in this regard made through genetic engineering have also been included.

Microbial production of L-phenylalanine: a review

Microbial production of L-phenylalanine by direct fermentation and by substrate conversion has been reviewed. The review also includes a discussion on different other methods for phenylalanine production, their advantages and disadvantages with mutants and genetically tailored strains. Biosynthesis of phenylalanine, its regulation in hyperproducing strains and recovery of phenylalanine has been discussed in brief.