Conserved quantities of Euler-Lagrange system via complex Lagrangian.

In this work we use complex Lagrangian technique to obtain Noether-like operators and the associated conserved quantities of an Euler-Lagrange (EL) system. We show that the three new conserved quantities namely, Noether conserved quantity, Lie conserved quantity and Mei conserved quantity reported by Fang et al. [1] for an EL-system and even more in numbers by Nucci [2] can also be obtained via complex variational formalism. Generally, a linear system of EL-equations possesses maximum 8-dimensional algebra of Noether symmetries and Noether's theorem yields related 8-first integrals. However, our methodology produces 10 Noether-like operators and 10 corresponding invariant quantities for the underlying system of equations. Among those ten first integrals, three (as named above) are reminiscent to those found in [1]. In addition, from the remaining list of conserved quantities several are similar to those reported in [2]. Moreover, the current study presents an alternative approach to compute invariant quantities of EL-systems and leads to interesting and fascinating results.

First toddler mesenteric lymphatic malformation in Malaysia - A case report.

This is the first reported case of a mesenteric lymphatic malformation in a toddler in Malaysia. It is a rare benign condition with incidence of 1 in 250,000 populations. Our patient presented to us at 2 years 11months old complaining of abdominal distension for 6 months without obstructive symptoms. Clinically there was a vague soft central abdominal mass. CT abdomen done revealed a large multiloculated intraperitoneal mesentery cystic mass within the central abdomen extending to pelvis. A semi-emergency laparotomy was performed. Intra-operatively the multiloculated mesenteric cyst measured 20cm x 30cm, adherent to the small bowel beginning at 12cm from duodeno-jejunal junction. Resection of the mesenteric cyst with adherent small bowel and primary anastomosis was done. Histopathological examination revealed multiple large lymphatic channels of various sizes in the mucosa and submucosa. Our patient has no signs of recurrence and remains symptom-free after 1 year since his surgery. Surgery with clear margins of resection is the recommended gold standard based on available literature. Type of surgical resection required will depend on the type of mesenteric lymphatic malformation. An awareness of this rare pathology is required to ensure proper management is given to these patients.

Neurosurgical contribution within a complex NF1 supraregional service.

OBJECTIVES: The goal of this study was to review and present neurosurgical related activity within a multidisciplinary nationally commissioned specialty neurofibromatosis type I (NF1) center. PATIENTS & METHODS: We reviewed all NF1 Neurosurgical MDTs, NF1 Neurosurgical clinics and all neurosurgical procedures carried out in NF1 patients over an 8-year period. RESULTS: Since the inception of the service in 2009, 1505 cases were discussed at our NF-1 multidisciplinary meeting, 171 clinic appointments in complex NF1 patients with neurosurgical pathologies and 43(cranial and spinal) operations were performed. CONCLUSIONS: The formation of a supraregional multidisciplinary team allows for a better understanding of the disease, a comprehensive evaluation of neuroimaging findings and a steep learning curve in the management of NF1 surgical conditions. We provide holistic treatment for these patients via direct care, specialist advice and liaison with local units.

Comparison of pterygomaxillary dysjunction with tuberosity separation in isolated Le Fort I osteotomies: a prospective, multi-centre, triple-blind, randomized controlled trial.

The aim of this trial was to compare two techniques of maxillary dysjunction, with 10mg/kg tranexamic acid as an adjuvant, in isolated non-segmented Le Fort I procedures. Two hundred patients were randomized to one of four groups: group A, pterygomaxillary dysjunction+saline; group B, tuberosity separation+saline; group C, pterygomaxillary dysjunction+tranexamic acid; and group D, tuberosity separation+tranexamic acid. Primary outcome measures were intraoperative blood loss and operating time, while the secondary outcome measures were surgical field assessment, need for blood transfusion, and duration of hospitalization. The data were analyzed using one-way analysis of variance (SPSS v. 17.0), and the level of significance was set at P<0.05. Results revealed that group D (tuberosity separation+tranexamic acid) had the least blood loss (mean 172 ml) and shortest operating times (mean 49 min), with the best surgical field. This group also exhibited the lowest drop in postoperative haemoglobin concentration (Hbgm/dl) and packed cell volume (PCV). Five patients, all in group A, required a blood transfusion and had an extra 24h of hospitalization. This trial revealed that the tuberosity separation technique with the use of tranexamic acid was the best protocol in producing the least blood loss, minimizing the operating time, and providing the best surgical field.

Mitotic Activity in Glioblastoma Correlates with Estimated Extravascular Extracellular Space Derived from Dynamic Contrast-Enhanced MR Imaging.

BACKGROUND AND PURPOSE: A number of parameters derived from dynamic contrast-enhanced MR imaging and separate histologic features have been identified as potential prognosticators in high-grade glioma. This study evaluated the relationships between dynamic contrast-enhanced MRI-derived parameters and histologic features in glioblastoma multiforme. MATERIALS AND METHODS: Twenty-eight patients with newly presenting glioblastoma multiforme underwent preoperative imaging (conventional imaging and T1 dynamic contrast-enhanced MRI). Parametric maps of the initial area under the contrast agent concentration curve, contrast transfer coefficient, estimate of volume of the extravascular extracellular space, and estimate of blood plasma volume were generated, and the enhancing fraction was calculated. Surgical specimens were used to assess subtype and were graded (World Health Organization classification system) and were assessed for necrosis, cell density, cellular atypia, mitotic activity, and overall vascularity scores. Quantitative assessment of endothelial surface area, vascular surface area, and a vascular profile count were made by using CD34 immunostaining. The relationships between MR imaging parameters and histopathologic features were examined. RESULTS: High values of contrast transfer coefficient were associated with the presence of frank necrosis (P = .005). High values of the estimate of volume of the extravascular extracellular space were associated with a fibrillary histologic pattern (P < .01) and with increased mitotic activity (P < .05). No relationship was found between mitotic activity and histologic pattern, suggesting that the correlation between the estimate of volume of the extravascular extracellular space and mitotic activity was independent of the histologic pattern. CONCLUSIONS: A correlation between the estimate of volume of the extravascular extracellular space and mitotic activity is reported. Further work is warranted to establish how dynamic contrast-enhanced MRI parameters relate to more quantitative histologic measurements, including markers of proliferation and measures of vascular endothelial growth factor expression.

Evaluation of a Preoperative Clinic for Women With Gynecologic Cancer.

Although many patients with gynecologic cancer undergo surgery, time constraints during the preoperative consultation may affect the accuracy of the information exchange, as well as compromise the quality of the patient assessment and care plan. Both put patients at a higher risk for complications during surgery and the postoperative period. This article describes an advanced practice RN-led preoperative assessment and education clinic designed to improve the quality of preoperative preparation and postoperative outcomes of patients with gynecologic cancer.

Exogenous administration of protease-resistant, non-matrix-binding IGFBP-2 inhibits tumour growth in a murine model of breast cancer.

BACKGROUND: Insulin-like growth factors (IGF-I and IGF-II) signal via the type 1 IGF receptor (IGF-1R) and IGF-II also activates the insulin receptor isoform A (IR-A). Signalling via both receptors promotes tumour growth, survival and metastasis. In some instances IGF-II action via the IR-A also promotes resistance to anti-IGF-1R inhibitors. This study assessed the efficacy of two novel modified IGF-binding protein-2 (IGFBP-2) proteins that were designed to sequester both IGFs. The two modified IGFBP-2 proteins were either protease resistant alone or also lacked the ability to bind extracellular matrix (ECM). METHODS: The modified IGFBP-2 proteins were tested in vitro for their abilities to inhibit cancer cell proliferation and in vivo to inhibit MCF-7 breast tumour xenograft growth. RESULTS: Both mutants retained low nanomolar affinity for IGF-I and IGF-II (0.8-2.1-fold lower than IGFBP-2) and inhibited cancer cell proliferation in vitro. However, the combined protease resistant, non-matrix-binding mutant was more effective in inhibiting MCF-7 tumour xenograft growth and led to inhibition of angiogenesis. CONCLUSIONS: By removing protease cleavage and matrix-binding sites, modified IGFBP-2 was effective in inhibiting tumour growth and reducing tumour angiogenesis.

Increased drug resistance is associated with reduced glucose levels and an enhanced glycolysis phenotype.

BACKGROUND AND PURPOSE: The testing of anticancer compounds in vitro is usually performed in hyperglycaemic cell cultures, although many tumours and their in vivo microenvironments are hypoglycaemic. Here, we have assessed, in cultures of tumour cells, the effects of reduced glucose levels on resistance to anticancer drugs and investigated the underlying cellular mechanisms. EXPERIMENTAL APPROACH: PIK3CA mutant (AGS, HGC27), and wild-type (MKN45, NUGC4) gastric cancer cells were cultured in high-glucose (HG, 25 mM) or low-glucose (LG, 5 mM) media and tested for sensitivity to two cytotoxic compounds, 5-fluorouracil (5-FU) and carboplatin, the PI3K/mTOR inhibitor, PI103 and the mTOR inhibitor, Ku-0063794. KEY RESULTS: All cells had increased resistance to 5-FU and carboplatin when cultured in LG compared with HG conditions despite having similar growth and cell cycle characteristics. On treatment with PI103 or Ku-0063794, only the PIK3CA mutant cells displayed increased resistance in LG conditions. The PIK3CA mutant LG cells had selectively increased p-mTOR, p-S6, p-4EBP1, GLUT1 and lactate production, and reduced reactive oxygen species, consistent with increased glycolysis. Combination analysis indicated PI103 and Ku-0063794 were synergistic in PIK3CA mutant LG cells only. Synergism was accompanied by reduced mTOR signalling and increased autophagy. CONCLUSIONS AND IMPLICATIONS: Hypoglycaemia increased resistance to cytotoxic agents, especially in tumour cells with a high dependence on glycolysis. Dual inhibition of the PI3K/mTOR pathway may be able to attenuate such hypoglycaemia-associated resistance.

MRI findings in cervical spinal cord type II neurological decompression sickness: a case report.

Decompression illness affecting the cervical spinal cord is uncommon. We report a case that presented with mixed signs and symptoms of cervical myelopathy and Type II neurological decompression sickness. This presented a diagnostic dilemma that required the use of magnetic resonance imaging (MRI) scan to elucidate the underlying cause. Cervical spine MRI revealed the presence of tiny hypointensities and edema within the spinal cord that corresponded to the clinical findings. The patient recovered with residual neurological deficits after hy-perbaric oxygen (HBO2) therapy. To our knowledge, these MRI findings have yet to been described in literature and we recommend the use of MRI to assist diving physicians in the management of complex cases as long as it does not delay recompression.

[Sacroiliac joint disorders in Abidjan: epidemiological, clinical, radiological and etiological characteristics]. / Atteintes sacroiliaques à Abidjan: aspects épidémiologiques, cliniques, radiologiques et étiologiques.

BACKGROUND: The sacroiliac joint remains unknown in sub-Saharan Africa. Studies about the sacroiliac diseases are rare Aim : Describe the epidemiological, clinical, radiological and etiological characteristics of sacroiliac joint diseases in Abidjan Methods : Retrospective and descriptive study concerning 17 patients hospitalized from February 2003 to April 2010 in the department of rheumatology of university hospital center of Cocody (Abidjan) for buttock pain or others functional signs evoking sacroiliac joint which were attested by radiographic lesions. We were interested on the epidemiological, clinical and radiological characteristics and the etiologies in the sacroiliac disease. RESULTS: The hospital prevalence of sacroiliac diseases was 0.55% corresponding in 17 of 3067 rheumatological diseases. The female sex predominated (82.35%) and the mean age of 25.58 years. Gyneco-obstetric events were the predominant risk factors (47.05%). Sacroiliac damage was manifested by inflammatory pain (64.7%) localized at the buttock or lumbar spine, radiating to the thigh (52.9%) and was accompanied by functional disability (82.2%) and fever was not present every time (64.7%). The physical findings were the tripod sign positive (58.8%), the monopodal backing positive (41.2%) and palpation painful of sacroiliac joint. The standard radiograph revealed a blurring aspect and widening of joint space associated with demineralization (68.4%), a joint space narrowing and erosion of articular banks (23.5%). The etiologies found were bacterial arthritis (82.3%) mainly pyogenic (70.58%), osteoarthritis (11.7%) and ankylosing spondylitis (5.9%). CONCLUSION: Sacroiliac joint diseases are rare in rheumatology practice in Abidjan, concern younger subjects and are dominated by pyogenic sacroiliitis.

Quality of life assessment in patients with dentofacial deformity undergoing orthognathic surgery--a systematic review.

The aim of this systematic review was to evaluate the benefits of orthognathic surgery to quality of life, the different motivations and perceptions of patients towards orthognathic surgery, and the various methods that have been used to analyze these changes, in patients who undergo orthognathic surgery for dentofacial deformities. A review of the literature was carried out, and articles published from 2001 to June of 2012 that satisfied the inclusion criteria were included in the review. A total of 21 articles were included. The results indicate that orthognathic patients experience an improvement in quality of life after surgery. Each individual patient has different motivations and expectations from the treatment. Also the use of validated instruments helped in quantifying results. Further research should be aimed at higher levels of evidence in study design, quantifying the changes for different types of dentofacial deformities and surgeries, and have a longer follow-up duration.

The concepts, diagnosis and management of early imaging changes after therapy for glioblastomas.

Since postoperative radiotherapy plus concomitant temozolomide followed by adjuvant temozolomide has become standard treatment for glioblastoma, the phenomenon of early post-treatment enlargement of the imaged tumour volume, usually without clinical deterioration, has become widely recognised. The term pseudoprogression has been used to describe a poorly understood pathophysiological process. In this review, the pathophysiological concepts, relevance, diagnosis and management of patients with 'pseudoprogression' and 'pseudoresponse' are discussed. Guidelines are given with respect to radiological imaging modality, mode and frequency. Further biological and clinical insights into these phenomena require carefully designed prospective studies.

HLA-DQ A1, -DQB1 and -DRB1 gene polymorphism--in Malay type 1 diabetes mellitus patients and their use for risk prediction.

HLA-DQA1, -DQB1, and -DRB1 gene polymorphism were analyzed to study type 1 DM susceptibility in Malay patients from Southeast Asia (Malaysia and Singapore). Patients showed significant increases in the occurrence of DQA1*0501 (50.7% vs. 20.4%; RR = 3.97; Pc < 0.01), DQB1*0201 (48% vs. 19.1%; RR = 3.86; Pc < 0.05), and DRB1*0301 (38.7 vs. 6.8%; RR = 8.36; 95% Pc < 0.05). Conversely, significant decreases were noted in the occurrence of DQA1*0601 (14.7% vs. 35.2%; RR = 0.33; Pc = 0.008) and DQB1*0601 (4% vs. 23.5%; RR = 0.16; Pc < 0.05) in type 1 DM patients. Using a logistic regression model, we derived a risk prediction model for type 1 DM in our indigenous Malay population based on the identified HLA genotypes. The RR for type 1 DM increases by a factor of 5.68 for every unit increase in the number of DRB1*0301 allele (P < 0.001), and decreases by a factor of 0.18 per unit increase in the number of DQB1*0601 allele (P < 0.001). After adjusting for these two HLA genotypes, DQA1*0501, DQB1*0201 and DQA1*0601 were not statistically significant as risk predictors. The lower incidence of type 1 DM in the Malay population may be contributed by the genotypic combinations of DR and DQ genes as well as the linkage disequilibria between susceptible and protective alleles.

Phosphor-Free Apple-White LEDs with Embedded Indium-Rich Nanostructures Grown on Strain Relaxed Nano-epitaxy GaN.

Phosphor-free apple-white light emitting diodes have been fabricated using a dual stacked InGaN/GaN multiple quantum wells comprising of a lower set of long wavelength emitting indium-rich nanostructures incorporated in multiple quantum wells with an upper set of cyan-green emitting multiple quantum wells. The light-emitting diodes were grown on nano-epitaxially lateral overgrown GaN template formed by regrowth of GaN over SiO(2) film patterned with an anodic aluminum oxide mask with holes of 125 nm diameter and a period of 250 nm. The growth of InGaN/GaN multiple quantum wells on these stress relaxed low defect density templates improves the internal quantum efficiency by 15% for the cyan-green multiple quantum wells. Higher emission intensity with redshift in the PL peak emission wavelength is obtained for the indium-rich nanostructures incorporated in multiple quantum wells. The quantum wells grown on the nano-epitaxially lateral overgrown GaN has a weaker piezoelectric field and hence shows a minimal peak shift with application of higher injection current. An enhancement of external quantum efficiency is achieved for the apple-white light emitting diodes grown on the nano-epitaxially lateral overgrown GaN template based on the light -output power measurement. The improvement in light extraction efficiency, η(extraction,) was found to be 34% for the cyan-green emission peak and 15% from the broad long wavelength emission with optimized lattice period.

Candidate biomarkers of extravascular extracellular space: a direct comparison of apparent diffusion coefficient and dynamic contrast-enhanced MR imaging--derived measurement of the volume of the extravascular extracellular space in glioblastoma multiforme.

BACKGROUND AND PURPOSE: ADC measurements have been shown to have an inverse relationship with tumor cell density. DCE-MR imaging modeling techniques can produce a measurement of the v(e), which would also be expected to have an inverse relationship with cell density. The objective of this study was to test the hypothesis that areas of increased cellularity, and therefore low ADC, would be expected to have a small EES (low v(e)). MATERIALS AND METHODS: Nineteen patients with GBM were recruited. All imaging was performed before surgery on a 3T MR imaging scanner. Imaging included diffusion tensor imaging, T1-weighted DCE-MR imaging, and anatomic sequences. Tumor VOIs were defined on the anatomic images and modified to contain only enhancing voxels. Parametric maps of ADC and v(e) were generated. Statistical analysis of ADC and v(e) was performed on both a voxel-by-voxel basis and comparison of median values. RESULTS: No correlation was demonstrated between ADC and v(e) in either a voxel-by-voxel analysis or comparison of median values (P = .124). CONCLUSIONS: This study failed to demonstrate a correlation between ADC and v(e). This is important because it suggests that though the mechanisms underlying these parameters are theoretically similar, they actually reflect different aspects of tumor microenvironment. Consequently ADC and v(e) should be considered to provide independent information about the properties of the EES.

Enhancing fraction in glioma and its relationship to the tumoral vascular microenvironment: A dynamic contrast-enhanced MR imaging study.

BACKGROUND AND PURPOSE: EnF is a newly described measure of proportional tumor enhancement derived from DCE-MR imaging. The aim of this study was to assess the relationship between EnF and the more established DCE-MR imaging parameters: K(trans), v(e), and v(p). MATERIALS AND METHODS: Forty-two patients with 43 gliomas (16 grade II, 3 grade III, and 24 grade IV) were studied. Imaging included pre- and postcontrast T1-weighted sequences through the lesion and T1-weighted DCE-MR imaging. Parametric maps of EnF, K(trans), v(e), and v(p) were generated. Voxels were classified as enhancing if the IAUC was positive (EnF(IAUC)(60>0)). A threshold of IAUC > 2.5 mmol.s was used to generate EnF(IAUC)(60>2.5). Both measures of EnF were compared with the DCE-MR imaging parameters (K(trans), v(e), and v(p)). RESULTS: In grade II gliomas, EnF(IAUC60>0) and EnF(IAUC60>2.5) correlated with v(p) (R(2) = 0.6245, P < .0005; and R(2) = 0.4727, P = .003) but not with K(trans) or v(e). In grade IV tumors, both EnF(IAUC60>0) and EnF(IAUC60>2.5) correlated with K(trans) (R(2) = 0.3501, P = .001; and R(2) = 0.4699, P < .0005) and v(p) (R(2) = 0.1564, P = .01; and R(2) = 0.2429, P = .007), but not with v(e). Multiple regression analysis showed K(trans) as the only independent correlate of both EnF(IAUC60>0) and EnF(IAUC60>2.5) for grade IV tumors. CONCLUSIONS: This study suggests that in grade II tumors, EnF reflects v(p) and varies due to changes in vascular density. In grade IV gliomas, EnF is affected by K(trans) with secondary associated changes in v(p).

Inhibitory effect of morinda citrifolia L. On lipoprotein lipase activity.

Efficacy of Morinda citrifolia L. leaf (MLE) and fruit extracts (MFE) in inhibiting lipoprotein lipase (LPL) was determined in vitro. The result of the study showed that the highest inhibition on the LPL activity was exhibited by MLE (66%+/- 2.1%), which is significantly higher than that demonstrated by MFE (54.5%+/- 2.5%), green tea extract (GTE) (54.5%+/- 2.6%), and catechin (43.6%+/- 6.1%). Percent of LPL inhibition increase with concentration of the extracts. Quantitative analysis of the extracts revealed the presence of high levels of (+)-catechin at 63.5 +/- 17 and 53.7 +/- 5.7 mg/g in MLE and MFE, respectively, although not as high as that found in GTE (530.6 +/- 42 mg/g). Appreciable amount of epicatechin was found in all extracts tested, while rutin was only found in MLE and MFE. The study suggested that both leaf and fruit of M. citrifolia may be used as antiobesity agents in body weight management.

Fabrication of a nano-cone array on a p-GaN surface for enhanced light extraction efficiency from GaN-based tunable wavelength LEDs.

We report on the fabrication of a nano-cone structured p-GaN surface for enhanced light extraction from tunable wavelength light emitting diodes (LEDs). Prior to p-contact metallization, self-assembled colloidal particles are deposited and used as a mask for plasma etching to create nano-cone structures on the p-GaN layer of LEDs. A well-defined periodic nano-cone array, with an average cone diameter of 300 nm and height of 150 nm, is generated on the p-GaN surface. The photoluminescence emission intensity recorded from the regions with the nano-cone array is increased by two times as compared to LEDs without surface patterning. The light output power from the LEDs with surface nano-cones shows significantly higher electroluminescence intensity at an injection current of 70 mA. This is due to the internal multiple scattering of light from the nano-cone sidewalls. Furthermore, we have shown that with an incorporation of InGaN nanostructures in the quantum well, the wavelength of these surface-patterned LEDs can be tuned from 517 to 488 nm with an increase in the injection current. This methodology may serve as a practical approach to increase the light extraction efficiency from wavelength tunable LEDs.