Convergence of per capita ecological footprint among BRICS-T countries: evidence from Fourier unit root test.

In recent years there has been a great deal of research into environmental pollution using a variety of techniques in response to growing environmental concerns. Convergence analysis, one of these techniques, helps determine whether the developing countries will catch up with the rich countries in pollution using unit root tests. However, the vast majority of the research in the field has generally used conventional unit root tests. Since many economic series contain structural breaks, using unit root tests that account for structural breaks is essential for accurate prediction. More specifically, if the series has a fractional process, conventional unit root tests may erroneously conclude that the departure from linearity is permanent. Moreover, the existing literature mainly uses gas emissions, such as carbon dioxide, which represent pollution weakly. Therefore, we use per capita ecological footprint (EF hereafter) as a more comprehensive pollution indicator of environmental degradation. In this direction, the study aims to determine whether BRICS-T countries' EF converges to the average of the BRICS-T for the 1992-2017 period. Besides the ADF unit root test, we employed the Fourier ADF unit root test, which considers the structural breaks, and the Fractional Frequency Fourier ADF unit root test, which accounts for structural breaks by considering fractional values. Our results showed that EF converges in Russia and Turkey according to the conventional ADF test, in China and Russia according to the Fourier ADF test, and in Brazil and China according to the Fractional Fourier Frequency test.

Effects of gel morphology on the lysozyme adsorption and desorption kinetics of temperature sensitive magnetic gel composites.

Tuning the adsorption and desorption rate constant of proteins is a hot topic for broad range of applications in biotechnology and medical science; especially controlled drug delivery and protein separation are the prominent examples in this field. In this study, Gel-MNPs (Poly(N-isopropylacrylamid) PNIPA-Magnetic Nano Particles) composites were synthesized by using different concentrations of monomer and cross-linker to observe the effect of gel morphology on the adsorption and desorption rate constant and kinetics of lysozyme protein. The synthesized composites were characterized by XRD, VSM, SEM and FTIR techniques. The characterization results showed that superparamagnetic Fe3O4 nanoparticles were synthesized inside the temperature sensitive PNIPA hydrogels. Fluorescence measurements were performed for monitoring the adsorption and desorption of lysozyme through Gel-MNPs composites. The adsorption process obeyed pseudo first and second order kinetic models at above and below the lower critical solution temperature (LCST) of PNIPA gels. Pseudo first order kinetic indicates physisorption, between the lysozyme and composite material for both adsorption and desorption. The adsorption was effective below LCST, but it was not effective at a temperatures higher than LCST; the adsorption rate constant was found between 0.59 and 0.082 s-1 at 22 °C. On the other side, samples show well desorption ability at the temperature above than LCST; the desorption rate constant was found between 0.080 and 0.092 s-1 at 45 °C. Moreover, the effects of monomer and cross-linker concentration on the adsorption and desorption kinetics are determined and discussed at the end of the manuscript.

Camphor Sulfonic Acid Doped Poly(3-hexylthiophene) Nanofilms: Optical and Electrical Properties.

Herein, we report the fabrication and characterization of Camphor Sulfonic Acid (CSA) doped Poly(3-hexylthiophene) (P3HT) nanofilms prepared at different substrate temperature on glass by simple wire bar coating method. Spectroscopic, optic, structural and electrical properties of the prepared nanofilms were characterized by atomic force microscopy (AFM), UV-Visible spectroscopy, fluorescence spectroscopy, X-ray diffraction, NKD spectroscopy, SEM and DC electrical measurements. The detailed electrical characterizations revealed that the conductivity of the P3HT nanofilms increased when the films are doped with CSA and the conductivity increased from 5.89×10⁻5 S/cm to 1.39 × 10⁻4 S/cm for 40 °C preparation temperature. Thus, it was confirmed that the substrate temperature plays an important role on the film structure and spectroscopic properties. Additionally CSA-doping changes the optical properties, especially when the films prepared at 40 °C.

One pot synthesis and characterization of Fe3O4 Nanorod-PNIPA Nanogel Composite for protein adsorption.

In this study, Fe3O4 Nanorod-PNIPA Nanogel Composite nanomaterial is synthesized, characterized and used for lysozyme adsorption. XRD, ATR-FTIR, AFM and SEM measurements reveal that nanorods-nanogels composite was prepared successfully. The diameter of nanorods and the average particle size of nanogels are found around 150nm and 300nm, respectively. VSM measurement shows that the Fe3O4 particles are in rod shape and has superparamagnetic behavior, no hysteresis and remnant is detected. The adsorption kinetic of lysozyme on composite material is studied via fluorescence method, and the adsorption reaction rate constant is calculated as 0.904s(-1) by using Langmuir-Hinshelwood pseudo second order model. Fe3O4 Nanorod-PNIPA Nanogel Composite is appeared as a fast catalyst for lysozyme like protein immobilization.

Effect of UV-light on the uniaxial tensile properties and structure of uncoated and TiO2 coated Bombyx mori silk fibers.

The effect of UV-light on the uniaxial tensile properties and the structure of uncoated and TiO2 coated silk fibers in the bave form by using sol-gel method was investigated with tensile testing and FT-IR/ATR spectroscopy methods after the silk filaments were exposed to UV-light with high intensity of 760W/m(2) for different times from 0.5h to 1day. It was clearly observed that TiO2 coating considerably increased the Young's modulus of the uncoated silk single filament by around 17% before the UV-irradiation. The yield point and the post yield region disappeared on the stress-strain curves of both uncoated and TiO2 coated silk filaments after UV-irradiation time higher than 1h. Except for the Young's modulus, most of the tensile characteristics of both uncoated and TiO2 coated silk filaments decreased remarkably with increasing UV-irradiation time, e.g., after 1h irradiation, although the Young's modulus slightly changed and ultimate tensile strength decreased by only around 18% and 23%, for the uncoated and TiO2 coated silk filaments, respectively; breaking extension decreased dramatically by 67% and 72%, respectively, for uncoated and TiO2 coated silk filaments. Only the Young's modulus of TiO2 coated silk filaments which can be considered as a more stable tensile characteristic became significantly higher than that of the uncoated silk filaments with increasing UV-irradiation time. After 1day irradiation, even though the uncoated silk filaments could not be tested and completely lost of their fiber properties, the TiO2 coated silk filaments showed a stress-strain curve in initial elastic region with Young's modulus of ∼13GPa which indicates considerable protective effect of TiO2 on the silk fiber structure, especially on the ß-sheet microcrystals against UV-radiation. The FT-IR/ATR spectral results showed that significant photodegradation took place in not only crystalline but also amorphous regions which were deduced from the decrease in the absorbance ratios of the bands assigned to CH3 rocking, Cα-Cß, Cα-C stretching vibrations in ß-sheet crystalline regions as well as the Amide I, II, and III bands for both crystalline and amorphous regions. Even though the ratio of crystalline to amorphous regions in uncoated silk filaments decreased significantly, the ratio in TiO2 coated silk filaments became almost constant with increasing UV-irradiation time which may indicate more stable ß-sheet microcrystals against photodegradation.

Cavernous sinus invasion and effect of immunohistochemical features on remission in growth hormone secreting pituitary adenomas.

AIM: We examined the cavernous sinus invasion and tumor biological markers that influence the remission rate. Cavernous sinus (CS) invasion was evaluated radiologically. Tumor biological markers consisting of the tumor cell growth parameter Ki-67 and the cancer cell vasculature marker of vascular endothelial growth factor (VEGF) were evaluated. MATERIAL AND METHODS: We examined 28 immunohistochemically proven GH secreting pituitary adenoma patients who had been operated via endoscopic transsphenoidal surgery at Department of Neurosurgery, Kocaeli University Hospital between 2003 and 2008. Pathology preparations were stained with Ki-67 and VEGF. We evaluated remission at the postoperative 6th week. The basal GH level, nadir GH level and IGF-1 levels were evaluated to determine remission. RESULTS: Remission was achieved in 6 of 18 patients (33%) who had cavernous sinus invasion. Remission was achieved in 7 of 10 patients (70%) who did not have cavernous sinus invasion. There was no correlation between the Ki-67 proliferation index and cavernous sinus invasion (p=0.593). There was a positive correlation between VEGF expression and cavernous sinus invasion (p=0.03). CONCLUSION: The remission rate found less in the cavernous sinus invasion group. No association was found between Ki 67 proliferation index and cavernous sinus invasion. We found that a positive correlation between VEGF expression and cavernous sinus invasion. VEGF expression can therefore indirectly affect remission via cavernous sinus invasion.

Detection and Evaluation of Intracranial Aneurysms with 3D-CT Angiography and Compatibility of Simulation View with Surgical Observation.

AIM: The aim of this study was to report our experience with a 64-channel computerized tomography (CT) scanner as the primary choice on the detection of intracranial aneurysms. Comparison of intracranial aneurysms with the simulated images obtained via three-dimensional computed tomography angiography (3D-CTA) in pterional approach was also aimed. MATERIAL AND METHODS: Among 288 consecutive patients who had intracranial aneurysms detected on 64-slice CTA, a total of 337 aneurysms were detected. CTA simulation images and intraoperative images were compared with regards to size, shape, and orientation. RESULTS: In one of the 22 CTA-negative cases, one aneurysm was detected in DSA and an additional aneurysm was detected in a patient operated with CTA. Aneurysm size, shape and direction were error free except a few cases. However, CTA was found to be insufficient to show particularly perforating arteries that were smaller than 2 mm in size. CONCLUSION: As a fast and noninvasive technique, CTA can be used as an initial examination in subarachnoid hemorrhage. Keeping the fact that there can be insufficiency in showing particularly small aneurysms in mind, DSA should be performed on CTA-negative cases and required cases.

Extended endoscopic transsphenoidal approach infrachiasmatic corridor.

An extended endoscopic transsphenoidal approach is required for skull base lesions extending to the suprasellar area. Inferior approach using the infrachiasmatic corridor allows access to the lesions through the tumor growth that is favorable for the extended transsphenoidal approaches. Infrachiasmatic corridor is a safer route for the inferior approaches that is made up by basal arachnoid membrane and Liliequist's membrane with its leaves (diencephalic and mesencephalic leaf). This area extends from the optic canal and tuberculum sella to the corpus mamillare. We performed extended endoscopic approach using the infrachiasmatic corridor in 52 cases, including tuberculum sella meningiomas (n:23), craniopharyngiomas (n:16), suprasellar Rathke's cleft cyst (n:6), pituitary adenoma (n:2), fibrous dysplasia (n:1), infundibular granulosa cell tumor (n:2), and epidermoid tumor (n:2). Total resection was achieved in 17 of 23 (74%) with tuberculum sellae meningioma using infrachiasmatic approach. Twenty patients presented with visual disorders and 14 of them improved. There were two postoperative cerebrospinal fluid (CSF) leakages and one transient diabetes insipidus and one permanent diabetes insipidus. Sixteen patients were operated on by the infrachiasmatic approach for craniopharyngiomas. Improvement was reached in seven of eight patients presented with visual disorders. Complete tumor resection was performed in 10 of 16 cases and cyst aspiration in 4 cases, and there were remnants in two cases. Postoperative CSF leakage was seen in two patients. Infrachiasmatic corridor provides an easier and safer inferior route for the removal of middle midline skull base lesions in selected cases.

[Sinonasal teratocarcinosarcoma]. / Sinonazal teratokarsinosarkom.

Sinonasal teratocarcinosarcoma is an extremely rare malignant neoplasm presenting with the characteristics of a malignant teratoma and carcinosarcoma. The most common sites of origin of teratocarcinosarcomas are the nasal cavity and paranasal sinuses. The clinical presentation is usually with nasal obstruction and episodes of epistaxis. Teratocarcinosarcomas are aggressive and rapidly growing tumors with a poor prognosis. The incidence of sinonasal teratocarcinomas is higher in men than women. Treatment is primarily surgery, followed by radiotherapy. In this article, we report a 46-year-old male case of sinonasal teratocarcinosarcoma who was admitted with complaints of pain and swelling around the right eye and treated surgically followed by radiotherapy.

Endoscopic approach to cavernous sinus aneurysm.

Aneurysms protruding into sellae may mimic pituitary tumors by compressing adjacent cranial nerves. Carotid-Cavernous aneurysms are rarely associated with mortality, and surgical intervention is recommended especially for neuro-ophthalmologic progression. In this report we presented a 51-year-old woman who had severe headache and neuro-ophthalmologic signs with the initial diagnosis of pituitary apoplexy on MRI (Magnetic Resonanse Imaging). However preoperative CTA (Computed Tomography Angiography) revealed a carotid cavernous aneurysm protruding into sellae. The patient underwent endovascular intervention and endoscopic transphenoidal approach for the removal of the hematoma compressing the cranial nerves. The patient's neuro-ophthalmologic symptoms were improved during the follow-up, which may be related due to rapid evacuation of the hematoma.

Endoscopic distinction between capsule and pseudocapsule of pituitary adenomas.

BACKGROUND: Pseudocapsules were first identified in pituitary adenoma surgery in 1936. Since then, the distinction between pituitary capsules and pseudocapsules has been unclear, and the definitions of these entities have varied. In this study, pituitary capsules and extracapsular dissection were examined retrospectively, intra- and extrapseudocapsular resection was evaluated, and dissection of the pituitary adenoma and pseudocapsule was examined prospectively. METHODS: Between January 2009 and May 2012, endoscopic transsphenoidal pituitary surgery was performed on 224 patients in the Department of Neurosurgery, Kocaeli University Faculty of Medicine, Turkey. Data for 174 patients were analyzed retrospectively between January 2009 and December 2011, and 50 patients treated between December 2011 and May 2012 were included in a prospective study. RESULTS: In the retrospective phase of the study, capsules were examined in 21 of the 174 patients on whom extracapsular resection had been performed. In the 50 cases treated between December 2011 and May 2012, dissection of the pituitary capsule, adenohypophysis, and pseudocapsule was performed. In 30 patients in the prospective phase of the study, pseudocapsules were identified during intraoperative endoscopic observation. Remission was achieved in 28 of 33 functioning adenomas in the prospective study. The mean follow-up period in this group was 13 months. CONCLUSION: The endoscopic and histopathological evidence provided in this study demonstrates that the pituitary capsule and pseudocapsule are distinct structures. In addition, it is also shown that extracapsular dissection can be performed in functioning adenomas that invade the suprasellar region. Significantly higher rates of total resection and higher remission rates were observed in cases where extra- and intrapseudocapsular dissection was required.

Growth kinetics of MPS-capped CdS quantum dots in self-assembled thin films.

For this study, we prepared colloidal CdS quantum dots using 3-mercaptopropyltrimethoxysilane as capping agent. Colloidal CdS quantum dots were directly deposited on glass substrates by a spin-coating process. Coated substrates were heat-treated between 225°C and 325°C for various heat treatment time intervals to investigate the growth kinetics of the quantum dots. Results showed that sizes of the CdS quantum dots grew approximately from 2.9 to 4.6 nm, and the E1s1s energy values shifted approximately from 3.3 to 2.7 eV. Results showed that the average size of quantum dots increase by thermal treatment due to Ostwald ripening. The thermal process used to grow the size of quantum dots was examined according to the Lifshitz-Slyozov-Wagner theory. The activation energy of CdS quantum dots in thin films was calculated at approximately 44 kJ/mol.

Endoscopic transphenoidal approach for fibrous dysplasia of clivus, tuberculum sellae and sphenoid sinus; report of three cases.

AIM: Fibrous dysplasia is a benign disease in which medullary bone is replaced by fibro-osseous tissue, and causes distortion and overgrowth of the involved bone and represents about 3% of all bone tumors. There is variability in the manifestation of Fibrous Dysplasia lesions with imaging techniques due to their proportional variations of fibrous to osseous tissue. Radiological differential diagnoses include meningioma, chordoma on MRI and Paget disease on CT imagings. MATERIAL AND METHODS: We report three cases of monostotic fibrous dysplasia, affecting clivus, tuberculum sellae, and sphenoid sinus through the pterygopalatine fossa. We performed pure endoscopic transphenoidal approach for those three cases with the guide of neuronavigation. Extended approach was used via binostril for fibrous dysplasia of clivus and Tuberculum sellae. RESULTS: Radiologic report revealed chordoma and meningioma for the two cases and fibrous dysplasia for the last case. Total resection of tuberculum sellae, subtotal resection of clivus and partial resection of sphenoid sinus lesions were performed. Pathology diagnosis were fibrous dysplasia in all three patients. CONCLUSION: Histopathological sampling provided by surgical approach should be obtained to establish the final diagnosis. Endoscopic approaches are convenient for skull base lesions even for biopsy or curative resections providing panoramic view and avoid brain retraction.

Microsurgical anatomy of membranous layers of the pituitary gland and the expression of extracellular matrix collagenous proteins.

BACKGROUND: There are several reports about the microanatomical and histological features of sellar and parasellar membranous structures and clinical studies about MMP proteinase as a predictive factor. However, studies on collagen contents of sellar and parasellar membranous structures are limited. We demonstrated the membranous structures surrounding the pituitary gland and defined extracellular matrix (ECM) collagenous proteins, collagen I-IV expression patterns of sellar and parasellar connective tissues. METHODS: The study was carried out on ten fresh postmortem human bodies at the Forensic Medicine Institution. Cavernous sinuses were resected with sellar structures and were stored at -80°C liquid nitrogen tanks. Medial wall of the cavernous sinus, pituitary capsule and pituitary tissue samples were obtained for RT-PCR. Opposite side specimens were used for histological and immune staining studies. Collagens I-IV were studied by immunohistochemical and reverse transcription polymerase chain reaction (RT-PCR) methods. FINDINGS: The pituitary capsule and medial wall were identified as two different structures. The fibrous membrane, as the third membrane, was identified as staying whole in eight of ten specimens. Increased type IV collagen was determined in the pituitary gland, medial wall and pituitary capsule, respectively, in both RT-PCR and immunhistochemical studies. Immunhistochemical studies revealed that collagen I was strongly expressed in both the medial wall and pituitary gland. CONCLUSION: Increased type IV collagen was detected especially in pituitary tissue, the medial wall and the pituitary capsule by immune staining and RT-PCR. Type IV collagen was considered to be an important factor in the progression of adenoma and invasion.

A new endoscopic surgical classification and invasion criteria for pituitary adenomas involving the cavernous sinus.

AIM: There are two major problems for the pituitary adenomas invading the Cavernous Sinus (CS); differentiation of extension and invasion and inability to demonstrate the medial wall via preoperative imaging methods. Two important corridors are defined in endoscopic cavernous sinus approaches; the lateral and medial corridor. MATERIAL AND METHODS: A retrospective analysis was performed in 400 endoscopic transphenoidal approaches and 360 pituitary adenomas underwent endoscopic transphenoidal surgery in our department between September 1997 and December 2010. 48 patients affected by the tumours involving the cavernous sinus were included in this study. RESULTS: We performed an intraoperative evaluation of cavernous sinus invasion considering visualization of the medial wall defect, intracavernous ICA segments, minor tumour extensions through small focal pit holes of the medial wall of CS or confirming carotid segments of CS by micro-doppler. Cavernous sinus involvement was classified into three types according to the medial and lateral corridor extension of the tumor as 25 isolated medial corridor involvement (Type I), 5 isolated lateral corridor involvement (Type II) and 18 total involvement (Type III). CONCLUSION: Our classification depends on fully surgical endoscopic approach supported by neuroimaging techniques and anatomical studies and shows a good predictive value for all cavernous sinus involvement.

Immunohistochemical analysis of TIMP-2 and collagen types I and IV in experimental spinal cord ischemia-reperfusion injury in rats.

BACKGROUND: Thoracic and thoracoabdominal aortic intervention carries a significant risk of spinal cord ischemia. The pathophysiologic mechanisms that cause hypoxic/ischemic injury to the spinal cord have not been totally explained. In normal spinal cord, neurons and glial cells do not express type IV collagen. Type IV collagen produced by reactive astrocytes is reported to participate in glial scar formation. Tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors that regulate the activity of the matrix metalloproteinases (MMPs). TIMP-2 binds strongly with MMP-2, facilitating activation by membrane-type MMP. Imbalance between TIMPs and MMPs can lead to excessive degradation of matrix components. Type IV collagen involved in the blood-brain barrier disruption and glial scar formation, TIMP-2 influences MMP-2 that controls degradation of collagen I and IV. OBJECTIVE: To examine the immunohistochemical analysis of TIMP-2 and collagen types I-IV in experimental spinal cord ischemia-reperfusion in rats. METHODS: Thirty-two male Wistar rats weighing 250-300 g were divided into four groups: group S: sham group (n = 8); group 0P: 30-minute occlusion without perfusion (n = 8); group 3P: 30-minute occlusion and 3-hour perfusion (n = 8); and group 24P: 30-minute occlusion and 24-hour perfusion (n = 8). Infrarenal aorta was cross-clamped at two sites by using two aneurysm clips for 30 minutes. Reperfusion was provided after removal of the clips. Lumbar spinal cord segments were removed for immunohistochemical analysis. RESULTS: TIMP-2 and collagen staining in 3-hour perfused (3P) group were nearly the same with sham group (S). TIMP-2 and collagen staining increased in the 24-hour perfused group. CONCLUSION: Alterations in collagen levels may relate to the biphasic breakdown of the blood-brain barrier and collagen staining in new cell types with relation to glial scar formation. Our results demonstrate that 3-hour perfusion after occlusion in hypoxic/ischemic spinal cord injury seems to be the critical reversible period.

Microsurgical and endoscopic anatomy of Liliequist's membrane and the prepontine membranes: cadaveric study and clinical implications.

BACKGROUND: Liliequist's membrane is mostly described as having a diencephalic leaf, mesencephalic leaf, and diencephalic-mesencephalic leaves in the literature. Also different descriptions of the prepontine membranes were reported. In this study, we visualized the regular structural forms of membranes without disturbing any attachments and defined infrachiasmatic and prepontine safety zones. We discussed the clinical significance of these structures. MATERIALS AND METHODS: The study was carried out on 24 adult human cadavers at the Morgue Specialization Department of the Forensic Medicine Institution following the initial autopsy examination. Liliequist's membrane and the prepontine membranes were explored after retraction of the frontal lobes. Dissections were performed under the operative microscope. A 0- and 30-degree, 2.7-mm angled rigid endoscope (Aesculap, Tuttlingen, Germany) was advanced through the prepontine cistern from the natural holes of membranes, or small holes were opened without damaging the surrounding structures. RESULTS: The basal arachnoid membrane (BAM) continued as Liliequist's membrane (LM) without any distinct separation in all specimens. The LM coursed over the posterior clinoids and split into two leaves as the diencephalic leaf (DL) and mesencephalic leaf (ML) in 18 specimens; the medial pontomesencephalic membrane (MPMM) coursed anterolaterally as a continuation of the ML and attached to the medial surfaces of the fifth and sixth nerves, joining with the lateral pontomesencephalic membrane (LPMM), which was also a posterolateral continuation of the ML in all specimens. The medial pontomedullar membrane (MPMdM) and lateral pontomedullar membrane (LPMdM) were observed in 21 specimens. The MPMdM membrane was a continuation of the MPMM, and the LPMdM was a continuation of the LPMM in all 21 specimens. CONCLUSION: We observed that the LM is a borderless continuation of the BAM. The MPMM and LPMM split from the ML without any interruptions. The MPMdM and LPMdM were a single membrane continuing from the MPMM and LPMM. We determined infrachiasmatic and prepontine areas that can be important for inferior surgical approaches.

Evaluation of early visual recovery in pituitary macroadenomas after endoscopic endonasal transphenoidal surgery: Quantitative assessment with diffusion tensor imaging (DTI).

BACKGROUND: Visual field analyses reflect the degree of the compression to the optic nerve that results the structural damage of the nerve. These structural damages can be evaluated by diffusion tensor imaging (DTI), which assesses the structural integrity of white matter tracts. Thus, we evaluated the quantitative assessment of early visual recovery in patients with pituitary macroadenomas, corresponding DTI with visual field analyses. METHODS: Seventy-two patients who had pituitary macroadenomas with visual field defects were included in the study retrospectively. All patients were operated on by pure endoscopic transphenoidal approach. Visual field assessment using Humphrey field analyzer and DTI with 3T magnet were performed in the preoperative and postoperative second day and sixth month. FINDINGS: Mean symptom duration was 14.7 ± 10.5 weeks in the full recovery group patients, 50.1 ± 29.1 weeks in partial recovery patients, and 92.4 ± 15.4 weeks in the ones with no recovery. There was a significant difference at p < 0.001 among the groups. On visual field analysis, the visual lost was mostly recognized at upper temporal levels preoperatively. Visual field findings of both eyes were improved in 80% of the patients. Among these, 25% revealed full recovery, 55.6% partial recovery, and 19.4% did not demonstrate significant changes. DTI assessments of affected sides revealed preoperative fractional anisotropy (FA) values below 0.400 and mean diffusivity (MD) values over 1,400 × 10(-6) mm(2) s(-1) were related with no visual improvement in the postoperative 6 months period. The percentage increase of mean FA values of the affected areas postoperatively were found to be 21.9% in totally responded patients, 20.6% in partial responded patients, and 9.8% in patients that did not respond. CONCLUSIONS: There is a correlation between DTI-derived FA values of the optic nerves and visual parameters. DTI assessments of the affected sides with FA and MD values may help to estimate the response of visual improvement to the surgical therapy in the early postoperative period.

Extended endoscopic transphenoidal approach for tuberculum sellae meningiomas.

PURPOSE: Removal of tuberculum sella (TS) meningiomas is traditionally performed through transcranial approaches. Wide use of the endoscope in transphenoidal pituitary surgery is recently accessible through the tuberculum sellae with an endoscope-assisted or purely endoscopic technique. Extended endoscopic approach is an important and alternative route for meningiomas, which are located on the midline originating from the tuberculum sella. However, cerebrospinal fluid (CSF) leakage is an important problem in extended endoscopic approaches. In this report, we discuss surgical limitations and nuances of endoscopic transphenoidal approach from a retrospective analysis of nine patients with TS meningiomas. METHODS: Endoscopic transphenoidal approach was performed for seven women and two men (mean age, 51.1 years; age range, 32-78 years) with TS meningiomas between July 2007 and March 2010 in the Department of Neurosurgery, Kocaeli, Turkey. RESULTS: Total removal was achieved in six of nine patients. An improvement of the preoperative visual deficits was observed in six of the nine patients. Multilayer closure was performed for reconstruction, and lumbar external drainage was used for all patients for 3-5 days. CSF leakage was not seen in any of the patients after the operation and removal of the drainage. CONCLUSION: Endoscopic extended transphenoidal approach is still not a standardized procedure for TS meningiomas, but it may be considered as an alternative procedure in selected cases.

Tectocerebellar dysraphism with vermian encephalocele.

Tectocerebellar dysraphism is a very rare malformation associated with encephalocele and tectal deformity. This article presents tectocerebellar dysraphism with a solely vermian content of encephalocele and tectal beaking defined by magnetic resonance imaging (MRI) in a 5-month-old girl who was successfully treated surgically and demonstrated excellent prognosis at the 4-year follow-up.