Analyzing Tear Fluid Composition by Synchronous Fluorescence for Diagnosing Dry Eye Disease and the Role of Phytotherapy Intervention.

PURPOSE: Tear fluid gained attention as a representative biological fluid. Its simple and non-invasive collection methods as well as richness of candidate biomarkers made it a potential diagnostic tool for different diseases such as dry eye. Synchronous fluorescence spectroscopy is a highly sensitive analytical tool that results in narrowing and enhanced peak resolution, and has a potential role in disease diagnosis, biomarker identification, and therapeutic monitoring. We applied synchronous fluorescence spectroscopy to monitor variations of tear fluid composition during the development of dry eye disease and to evaluate the potential effects of phytotherapy. METHODS: Dry eye model was induced in Chinchilla rabbits by instillation of 1% atropine sulfate ophthalmic solution. Then, the tear fluid was collected at 3, 7, and 14 days and subjected to synchronous fluorescence spectroscopy. Phytotherapy was achieved by topical instillation of 20 µl of water extracts of pomegranate peel or green tea powders. RESULTS: The fluorescence results revealed changes in the structure of tear fluid over time and the eye is subjected to toxification due to oxidative stress. In addition, dry eye disease was found to affect the metabolic/energetic state of the eye. On the other hand, phytotherapy led to enhancement of the metabolic/biosynthesis state due to activation of flavin adenine dinucleotide-associated proteins. CONCLUSION: There was change in the electrical conductivity of tear fluid proteins. In the case of dry eyes, they became electrical insulators, while in the case of treatment with extracts, their electrical conductivity properties improved. The effects of phytotherapy can be related to the high content of ellagic acid and anthocyanin of pomegranate extract, while in green tea, they are related to catechins and phenolic compounds.

Linking Cognitive Impairment with Amyloid-ß Accumulation in Alzheimer's Disease: Insights from Behavioral Tests and FTIR Spectroscopy.

Background: Alzheimer's disease (AD) is a neurodegenerative disorder that progresses over time. Fourier Transform Infrared Spectroscopy (FTIR) analysis gives identification of the main metabolic changes that happen during neurodegeneration, by monitoring biochemical and molecular structure alterations that can help in AD diagnosis or treatment approach. Objective: The aim of the present work is to assess AD hallmarks in molecular structure of retina and monitor accumulation of amyloid beta42(Aß42) in brain and retina during disease progression. Methods: AD induced in rats by Aluminum Chloride (AlCl3). Retinal molecular structure during disease progression for 2,4,6 and 8 weeks was assessed by Fourier-transform infrared spectroscopy (FTIR) and the incidence of the disease was confirmed by a behavioural assessment; the Morris Water Maze test. Aß42 levels in the brain and retina were also measured. Results: The results indicated that cognitive impairment starting from 6 weeks of AlCl3 administration. Retinal concentration of Aß42 was significant increase (p < 0.05) from 2 weeks that precedes the observed increase of Aß42 in the brain which appeared after 4 weeks of AlCl3 administration. Multivariate principal component analysis discovers that the variance noticed in the infrared spectra due to AD condition and it is time dependent for progression of the disease. Conclusions: The accumulation of Aß42 is a sensitive early biomarker in retina for AD. FTIR analysis of the retina revealed changes in hydrogen bond formation or destruction, alterations in lipid chain length and branching accompanied by depleted lipid content and carbonization, as well as degeneration of the retinal tissue due to AD.

Prognosis of Biomarker of Alzheimer's Disease in the Function of the Retina and Secondary Molecular Structure Variation of the Retina and Brain.

Alzheimer's disease (AD) is one of the most serious neurodegenerative diseases in the globe. As a result, there is an acute need to discover indications that allow for early disease detection. There is growing scientific data showing the similarities between the eye and other central nervous system components, suggesting that information obtained in ophthalmic research might be valuable in the study and diagnosis of AD. Fifty male albino Wistar rats were separated into five groups: the first group served as control, and the other four groups of animals were administrated aluminium chloride (AlCl3) in a dose of 100 mg/kg body weight (b.w.) for 2, 4, 6, and 8 weeks, respectively. Insights into the function of the retina by electroretinogram (ERG) and the changes thought to have occurred in the molecular structure of the retina and brain using Fourier transform infrared spectroscopy (FTIR) as a result of AD progression induced by AlCl3 in rats were done. Moreover, the measurement of acetylcholinesterase (AchE) was done. After 6 and 8 weeks of AlCl3 injection, there was a substantial reduction (p ≤ 0.05) in a- and b-wave amplitudes and a significant rise (p ≤ 0.05) in implicit time compared to controls. A significant elevation (p ≤ 0.05) of AchE content was observed after 4, 6, and 8 weeks. FTIR revealed a significant increase (p ≤ 0.05) of ß-turn and ß-sheet content associated with significant decrease (p ≤ 0.05) of α-helix content for all groups administrated with AlCl3. Our findings suggest that retinal biomarkers such as ERG of the retina may be used as a screening tool for detection of AD. Secondary structural changes in the proteins of the retina and the brain were similar in AD rats' model and precede retinal dysfunction.

Multi-parametric arterial spin labeling and diffusion-weighted imaging of paranasal sinuses masses.

PURPOSE: To evaluate arterial spin labeling (ASL) and diffusion-weighted imaging (DWI) in discrimination of benign from malignant paranasal sinus (PNS) tumors. MATERIAL AND METHODS: A prospective study was done upon 42 cases of PNS masses that underwent magnetic resonance ASL and DWI of the head. Tumor blood flow (TBF) and apparent diffusion coefficient (ADC) of the masses were calculated by two observers. The pathological diagnosis was malignant (n = 28) and benign (n = 14) cases. RESULTS: For both observers, the malignant PNS masses had significantly higher TBF (P < 0.001, 0.001) and lower ADC (P < 0.001, 0.001) than in benign masses. The ROC curve analysis of TBF, The threshed TBF was (121.45, 122.68 mL/100 g/min) used for differentiation between benign and malignant PNS masses, revealed sensitivity (92.9%, 89.3%), specificity (85.7%, 85.7%), accuracy (90.5%, 88.1%) and the AUC was 0.87 and 0.86 by both observers. the ROC curve analysis of ADC, The threshold ADC (1.215, 1.205 X10-3mm2/s) was used for differentiation between benign and malignant PNS masses, revealed sensitivity (96.4%, 89.3%), specificity (78.6%, 78.6%), accuracy of (90.5%, 85.7%) and the AUC was 0.93 and 0.92 by both observers. Combined analysis of TBF and ADC used for differentiation between benign and malignant PNS masses had revealed sensitivity (96.4%, 89.3%), specificity (92.9%, 85.7%) accuracy of (95.2%, 88.1%) and AUC. (0.995, 0.985) for both observers. CONCLUSION: Combined using of TBF and ADC have a role in differentiation malignant from benign PNS masses.

Impact of COVID-19 pandemic on lower urinary tract symptoms in patients with benign prostatic hyperplasia and predictors of urine retention in such patients.

OBJECTIVES: We assess the effect of coronavirus disease 2019 (COVID-19) on lower urinary tract symptoms (LUTS) of patients with benign prostatic hyperplasia (BPH). Moreover, we delineate risk factors for urine retention in such patients. METHODS: All COVID-19 infected males were expeditiously evaluated. All enrolled patients were assessed using the International Prostate Symptom Score (IPSS), uroflowmetry, and pelvi-abdominal ultrasonography for prostate volume and postvoiding residual urine (PVR) estimation. RESULTS: Fifty patients, who were diagnosed with BPH, were enrolled. The mean age (±SD) was 62.64 ± 7.69. In the pre- and post-COVID-19 group, the mean (±SD) IPSS was 13.42 ± 4.32 and 26.62 ± 5.77, respectively (P < .001), while PVR was 90.40 ± 32.75 and 185.42 ± 73.42, respectively (P < .001), and maximum flow rate was 14.40 ± 2.75 and 10.74 ± 3.43, respectively (P < .004). After infection with COVID-19, 13 (26%) patients were managed by urethral catheter fixation owing to urine retention. On bivariate analysis, age, diabetes, large prostate on digital rectal examination, alpha-blocker monotherapy, microscopic hematuria, positive urine culture, and pre-COVID-19 IPSS were significantly correlated with urine retention (P < .001, P = .01, P < .001, P = .06, P < .001, P = .04, and P < .001, respectively). On multivariate analysis, age, pre-COVID-19 IPSS, and positive urine culture were the independent predictors of urine retention (P = .05, P < .001, and P = .01, respectively). CONCLUSION: LUTS in BPH patients were significantly affected by COVID-19. COVID-19 increases IPSS leading to a change in the treatment modality of BPH. On multivariate analysis, age, pre-COVID-19 IPSS, and positive urine culture were the independent predictors of urine retention post COVID-19 infection.

Duration of Medical Treatment of Benign Prostatic Hyperplasia: Impact on Urodynamics and Post-Prostatectomy Outcome.

OBJECTIVES: The aim of this study was to assess whether the duration of preoperative benign prostatic hyperplasia (BPH) medication would affect the pressure flow study (PFS) parameters and the outcome of prostate surgery or not. MATERIAL AND METHODS: A retrospective study involving patients with LUTS/BPH aged 50 years or older who were compliant with BPH medications. PFS was performed prior to prostate surgery to determine BOO degree and detrusor overactivity. The efficacy of prostate surgery was determined at 3 and 6 months after surgery using the I-PSS, QOL index, Q-max, and PVR. Patients were categorized into group A, who received treatment for 12 months or less, and group B, who received the treatment for 12 months or more. The categorization starts once the patient prefers surgical intervention. RESULTS: A total of 114 patients were enrolled, 50 in group A and 64 patients in group B. The mean duration, in months, of medical treatment was 9.52 ± 2.24 and 22.50 ± 4.35 in group A and group B, respectively. Pdet@Qmax is significantly (p = 0.02) higher in patients of group B (63.85 ± 11.34 vs. 94.75 ± 19.53). The detrusor overactivity amplitude is slightly higher in group A (36.42 ± 37.27 vs. 16.42 ± 28.38) (p = 0.3). The mean I-PSS, Q-max, and PVR at 1, 3, and 6 months were comparable between the groups. CONCLUSION: After 24 months of BPH medical treatment, no profound PFS changes that may affect the decision of prostate surgery were observed. Patients who completed 24 months of medical treatment were safe as regards to detrusor muscle contractility with no urge to undergo prostate surgery earlier.

Mitochondrial dysfunction and serum lactate as a biomarker for the progression and disability in MS and its correlation with the radiological findings.

Objective: To study the serum lactate level in MS and to explore its correlation with the progression and disability in multiple sclerosis (MS), and the important role of mitochondrial dysfunction in the pathogenesis of MS.Methods: This case-control study included 80 participants, involved 50 MS patients and 30 normal healthy controls. Detailed history taking, complete neurological examination, and clinical evaluation of the disability using the Expanded Disability Status Scale (EDSS) were done for all patients. Level of serum lactate was measured in both groups and was correlated with EDSS, MS subtypes, MRI brain, and MRS findings.Results: Serum lactate in MS patients was about three and half times higher than serum lactate levels of healthy controls (22.87 ± 5.92 mg/dl versus 6.39 ± 0.9 6.39 ± 0.91, p < 0.001). Importantly, serum lactate values were increased in MS cases with a progressive course compared with MS cases with RR course. Also, there were linearly correlations linking serum lactate levels and the duration of MS (r = 0.342, P = 0.015), relapses numbers (r = 0.335, P = 0.022), and EDSS (r = 0.483, P < 0.001). Also, there were strong positive correlations between serum lactate and Lipid/Lactate (r = 0.461, P = 0.001), periventricular lesion (r = 0.453, P = 0.005), and moderate positive correlations between serum lactate and juxtacortical lesion (r = 0.351, P = 0.02), and infratentorial lesion (r = 0.355, P = 0.02).Conclusion: Measurement of serum lactate may be helpful in MS and this supports the hypothesis of the critical role of mitochondrial dysfunction and axonal damage in MS.Registration of Clinical Trial Research: ClinicalTrials.gov ID: NCT04210960.

The role of high-resolution Computer Tomography in prediction of the round window membrane visibility and the feasibility of the round window electrode insertion.

OBJECTIVE: The aim of this work is to assess the role of pre-operative high-resolution computerized tomography (HRCT) in prediction of the round window membrane (RWM) visibility and the feasibility of round window electrode insertion. MATERIALS AND METHODS: Retrospective study on a series of 97 cases of cochlear implant (CI) who were implanted in tertiary referral centers. We reviewed HRCT of all cases, and we implicated two radiological measurements on HRCT which are membrano-facial angle (MFA) and length of the bony overhang of the round window niche (RWN). We reviewed the intra-operative surgical video recordings of all cases for detection of the type of RWM visibility, according to The St Thomas' Hospital classification. RESULTS: The MFA was 21.9 ± 14.5. The length of the bony overhang of the RWN was 2.4 ± 0.33 mm. About 37% of the studied patients needed cochleostomy. The best cut-off of MFA in the prediction of the RW (type 2B and 3) was ≥ 15.1o with sensitivity 100%, and specificity 82%. CONCLUSION: HRCT offers highly reliable and reproducible measurements for the prediction of RWM visibility and, therefore, prediction of the utility of the RW approach for electrode insertion. Membrano-facial angle (MFA) is a new measurement that can be used for this purpose.

XRD and ATR-FTIR techniques for integrity assessment of gamma radiation sterilized cortical bone pretreated by antioxidants.

Terminal sterilization of bone allograft by gamma radiation is required to reduce the risk of infection. Free radical scavengers could be utilized to minimize the deteriorating effects of gamma radiation on bone allograft mechanical properties. The objective of this research is to assess the changes in structural and chemical composition induced by hydroxytyrosol (HT) and alpha lipoic acid (ALA) free radical scavengers in gamma sterilized cortical bone. Bovine femurs specimens were soaked in different concentrations of HT and ALA for 7 and 3 days respectively before irradiation with 35 KGy gamma radiation. The attenuated total reflection-Fourier transform infrared spectroscopy and the X-ray diffraction techniques were utilized to analyze the changes in chemical composition induced by irradiation in the presence of free radical scavengers. A significant increase in the proportion of amide I and amide II to phosphate was noticed in the irradiated group, while in the pretreated groups with ALA and HT this effect was minimized. In addition, gamma radiation reduced the mature to immature cross links while ALA and HT alleviated this reduction. No significant changes were noticed in the mineral crystallinity or crystal size. Bone chemical structure has been changed due to gamma irradiation and these changes are mainly relevant to amide I, amide II proportions and collagen crosslinks. The deteriorating effects of gamma sterilization dose (35 kGy) on chemical structure of bone allograft can be alleviated by using (HT) and (ALA) free radical scavengers before irradiation.

Biomechanical properties enhancement of gamma radiation-sterilized cortical bone using antioxidants.

Gamma radiation sterilization is the method used by the majority of tissue banks to reduce disease transmission from infected donors to recipients through bone allografts. However, many studies have reported that gamma radiation impairs the structural and mechanical properties of bone via formation of free radicals, the effect of which could be reduced using free radical scavengers. The aim of this study is to examine the radioprotective role of hydroxytyrosol (HT) and alpha lipoic acid (ALA) on the mechanical properties of gamma-sterilized cortical bone of bovine femur, using three-point bending and microhardness tests. Specimens of bovine femurs were soaked in ALA and HT for 3 and 7 days, respectively, before being exposed to 35-kGy gamma radiation. In unirradiated samples, both HT and ALA pre-treatment improved the cortical bone bending plastic properties (maximum bending stress, maximum bending strain, and toughness) without affecting microhardness. Irradiation resulted in a drastic reduction of the plastic properties and an increased microhardness. ALA treatment before irradiation alleviated the aforementioned reductions in maximum bending stress, maximum bending strain, and toughness. In addition, under ALA treatment, the microhardness was not increased after irradiation. For HT treatment, similar effects were found. In conclusion, the results indicate that HT and ALA can be used before irradiation to enhance the mechanical properties of gamma-sterilized bone allografts.

Multi-parametric arterial spin labelling and diffusion-weighted magnetic resonance imaging in differentiation of grade II and grade III gliomas.

PURPOSE: To assess arterial spin labelling (ASL) perfusion and diffusion MR imaging (DWI) in the differentiation of grade II from grade III gliomas. MATERIAL AND METHODS: A prospective cohort study was done on 36 patients (20 male and 16 female) with diffuse gliomas, who underwent ASL and DWI. Diffuse gliomas were classified into grade II and grade III. Calculation of tumoural blood flow (TBF) and apparent diffusion coefficient (ADC) of the tumoral and peritumoural regions was made. The ROC curve was drawn to differentiate grade II from grade III gliomas. RESULTS: There was a significant difference in TBF of tumoural and peritumoural regions of grade II and III gliomas (p = 0.02 and p =0.001, respectively). Selection of 26.1 and 14.8 ml/100 g/min as the cut-off for TBF of tumoural and peritumoural regions differentiated between both groups with area under curve (AUC) of 0.69 and 0.957, and accuracy of 77.8% and 88.9%, respectively. There was small but significant difference in the ADC of tumoural and peritumoural regions between grade II and III gliomas (p = 0.02 for both). The selection of 1.06 and 1.36 × 10-3 mm2/s as the cut-off of ADC of tumoural and peritumoural regions was made, to differentiate grade II from III with AUC of 0.701 and 0.748, and accuracy of 80.6% and 80.6%, respectively. Combined TBF and ADC of tumoural regions revealed an AUC of 0.808 and accuracy of 72.7%. Combined TBF and ADC for peritumoural regions revealed an AUC of 0.96 and accuracy of 94.4%. CONCLUSION: TBF and ADC of tumoural and peritumoural regions are accurate non-invasive methods of differentiation of grade II from grade III gliomas.

Analytical Study of Fuel Switching from Heavy Fuel Oil to Natural Gas in clay brick factories at Arab Abu Saed, Greater Cairo.

Arab Abu Saed area in Giza governorate, south to Cairo contains more than 228 clay brick kilns represent the largest cluster of brickworks in Egypt. Burning of Heavy Fuel Oil (HFO) in such kilns is the main source of air pollution in the surrounding locations. In this study, investigation of switching the fuel used in brick kilns from (HFO) to Natural Gas (NG) is carried out and the pollution loads are assessed in both cases. In addition, two Gaussian dispersion plume models are employed to estimate the concentration of primary pollutants; PM10, SO2, and NO2 at seven locations in the vicinity of Arab Abu Saed to determine the most adversely affected locations. Statistical analysis is applied to evaluate the correlation and conformity of the results of both models. Results show that using of NG leads to a significant reduction of pollution loads of PM10, SO2 and NO2 reaches 96%, 72%, and 24% respectively. In addition, the reduction of naturally occurring radionuclides in air is analyzed. Activity concentrations of Ra-226, Th-232 and K-40 in Bq/l for HFO were measured using HPGe detector for six HFO samples. Exposure due to air submersion of naturally occurring radionuclides in the study area leads to annual equivalent dose ranged between 2.16 mSv/y (received by Uterus) and 14 mSv/y (received by skin), and average effective dose 2.65 mSv/y which represent valuable exposure.

Clinical Applications of Arterial Spin Labeling in Brain Tumors.

The aim of this review was to review the basic background, technique, and clinical applications of arterial spin labeling in brain tumors. Arterial spin labeling is used for differentiation of brain tumors from nonneoplastic lesions such as infarction and infection. It has a role in the grading of gliomas and in the differentiation of gliomas from lymphomas and metastasis. It is used for detection of the best biopsy site and prediction of treatment response. Arterial spin labeling is used for the assessment of extra-axial tumors and pediatric tumors. Last, it has a role in the differentiation of tumor recurrence from postradiation changes and in monitoring patients after therapy.

Differentiating Glioblastomas from Solitary Brain Metastases Using Arterial Spin Labeling Perfusion- and Diffusion Tensor Imaging-Derived Metrics.

OBJECTIVE: We sought to differentiate glioblastomas from solitary brain metastasis using arterial spin labeling perfusion (ASL)- and diffusion tensor imaging (DTI)-derived metrics. METHODS: A prospective study was done on 36 patients with provisional diagnosis of glioblastomas versus brain metastasis who underwent ASL and DTI of the brain. The tumor blood flow (TBF) and DTI metrics (fractional anisotropy [FA] and mean diffusivity [MD]) of the enhancing tumoral and peritumoral parts were measured. RESULTS: There was a significant difference of TBF (P = 0.001) and MD (P = 0.001) of the tumoral and peritumoral parts of glioblastoma and metastasis (P = 0.001). There was a significant difference of FA of peritumoral part (P = 0.001) and insignificant difference of tumoral part (P = 0.06) between glioblastomas and metastasis. The cutoff of TBF of tumoral and peritumoral parts used for differentiation were 29.7 and 17.8 (mL/100 g/minute) revealed an area under the curve (AUC) of 0.943 and 0.937 with accuracy of 91.7% and 88.9%. The cutoff of MD of tumoral and peritumoral parts were 1.27 and 1.33 (10-3 mm2/second) revealed AUC of 0.840 and 0.987 and accuracy of 83.3% and 91.7%, respectively. Combined TBF, MD, and FA of the peritumoral part revealed AUC of 0.984 and accuracy of 91.7%. CONCLUSIONS: A combination of ASL- and DTI-derived metrics of the peritumoral part can be used for differentiation of glioblastomas from solitary brain metastasis.

Differentiation of Primary Central Nervous System Lymphoma From Glioblastoma: Quantitative Analysis Using Arterial Spin Labeling and Diffusion Tensor Imaging.

OBJECTIVE: Differentiation of primary central nervous system lymphoma (PCNSL) from glioblastoma using arterial spin labeling perfusion and diffusion tensor imaging (DTI). METHODS: We performed a prospective study of 31 patients with a provisional diagnosis of PCNSL and glioblastoma who underwent conventional magnetic resonance imaging, DTI, and arterial spin labeling of the brain. The tumor blood flow (TBF), mean diffusivity (MD) plus fractional anisotropy (FA) of the mass were measured. The final diagnosis was confirmed by pathological examination. RESULTS: The TBF of PCNSL (26.41 ± 4.03 mL/100 g/minute) was significantly lower than that of glioblastoma (51.08 ± 3.9 mL/100 g/minute; P = 0.001). The TBF cutoff (35.73 mL/100 g/minute) used for differentiation showed area under the curve (AUC) of 0.93, accuracy of 95.2%, sensitivity of 91.7%, and specificity of 100%. The MD of PCNSL (0.87 ± 0.2X 10-3 mm2/second) was significantly lower than that of glioblastoma (0.87 ± 0.2 × 10-3 mm2/second; P = 0.01). The MD cutoff (0.935 × 10-3 mm2/second) used for differentiation showed an AUC of 0.73 and accuracy of 66.7% and a sensitivity of 75% and specificity of 55.6%. The FA of PCNSL (0.253 ± 0.05) was significantly greater than that of glioblastoma (0.135 ± 0.06; P = 0.001). The FA cutoff (0.185) used for differentiation revealed an AUC of 0.944 and accuracy of 85.7% and a sensitivity of 83.3% and specificity of 88.9%. The combined TBF, MD, and FA cutoffs revealed an AUC of 0.96 and accuracy of 95.5% and a sensitivity of 83.3% and specificity of 100%. CONCLUSION: The noninvasive imaging parameters using TBF and DTI might help in differentiating PCNSL from glioblastoma.

Differentiation of residual/recurrent gliomas from postradiation necrosis with arterial spin labeling and diffusion tensor magnetic resonance imaging-derived metrics.

PURPOSE: The aim of this study is to differentiate recurrent/residual gliomas from postradiation changes using arterial spin labeling (ASL) perfusion and diffusion tensor imaging (DTI)-derived metrics. METHODS: Prospective study was conducted upon 42 patients with high-grade gliomas after radiotherapy only or prior to other therapies that underwent routine MR imaging, ASL, and DTI. The tumor blood flow (TBF), fractional anisotropy (FA), and mean diffusivity (MD) of the enhanced lesion and related edema were calculated. The lesion was categorized as recurrence/residual or postradiation changes. RESULTS: There was significant differences between residual/recurrent gliomas and postradiation changes of TBF (P = 0.001), FA (P = 0.001 and 0.04), and MD (P = 0.001) of enhanced lesion and related edema respectively. The area under the curve (AUC) of TBF of enhanced lesion and related edema used to differentiate residual/recurrent gliomas from postradiation changes were 0.95 and 0.93 and of MD were 0.95 and 0.81 and of FA were 0.81 and 0.695, respectively. Combined ASL and DTI metrics of the enhanced lesion revealed AUC of 0.98, accuracy of 95%, sensitivity of 93.8%, specificity of 95.8%, positive predictive value (PPV) of 93.8%, and negative predictive value (NPV) of 95.8%. Combined metrics of ASL and DTI of related edema revealed AUC of 0.97, accuracy of 92.5%, sensitivity of 93.8%, specificity of 91.7%, PPV of 88.2%, and NPV of 95.7. CONCLUSION: Combined ASL and DTI metrics of enhanced lesion and related edema are valuable noninvasive tools in differentiating residual/recurrent gliomas from postradiation changes.

DNA Hybridization on Chitosan-Functionalized Silicon Substrate.

The ability of DNA to capture oligonucleotide molecules in solution is of great importance in genetics, medical diagnostics, and drug discovery. The DNA hybridization event in which the probe, which is usually a single-stranded DNA (ssDNA) covalently immobilized on a functionalized surface, recognizes the complementary target and forms a stable duplex structure that is the basis of highly specific bio recognizing devices. In this computational study, molecular modeling and Quantitative Structure Activity Relationship (QSAR) calculations were utilized at PM3 level in order to evaluate the interaction of aldehyde ssDNA on chitosan-functionalized silicon substrate and the biological activity of the proposed compounds. Molecular modeling of ssDNA 5'-(TTCA) attached on chitosan- functionalized silicon dioxide substrate was carried out. Molecular modeling and QSAR calculations were utilized at MM3 level in order to evaluate the interaction of target DNA on DNA probe on chitosan-functionalized silicon substrate through hydrogen bonding and the biological activity of the proposed compounds.

Effect of mineral constituents in the bioleaching of uranium from uraniferous sedimentary rock samples, Southwestern Sinai, Egypt.

Bioleaching, like Biotechnology uses microorganisms to extract metals from their ore materials, whereas microbial activity has an appreciable effect on the dissolution of toxic metals and radionuclides. Bioleaching of uranium was carried out with isolated fungi from uraniferous sedimentary rocks from Southwestern Sinai, Egypt. Eight fungal species were isolated from different grades of uraniferous samples. The bio-dissolution experiments showed that Aspergillus niger and Aspergillus terreus exhibited the highest leaching efficiencies of uranium from the studied samples. Through monitoring the bio-dissolution process, the uranium grade and mineralogic constituents of the ore material proved to play an important role in the bioleaching process. The tested samples asserted that the optimum conditions of uranium leaching are: 7 days incubation time, 3% pulp density, 30 °C incubation temperature and pH 3. Both fungi produced the organic acids, namely; oxalic, acetic, citric, formic, malonic, galic and ascorbic in the culture filtrate, indicating an important role in the bioleaching processes.

FTIR assessment of the effect of Ginkgo biloba leave extract (EGb 761) on mammalian retina.

Ginkgo biloba extract has been therapeutically used for several decades to increase peripheral and cerebral blood flow as well as for the treatment of dementia. The extract contains multiple compounds such as flavonoids and terpenoids that are thought to contribute to its neuroprotective and vasotropic effects. In this study, we investigated the effect of prolonged administration of EGb 761, up to 10 weeks, on mammalian retina using Fourier transform infrared spectroscopy (FTIR). Two main groups were involved in this study: the normal group (n = 10); and EGb-administrated group (n = 50) that received-orally-a dose of 40 mg/kg/day EGb 761. The results demonstrated that EGb administration was associated with different beneficial effects on the retinal constituents especially the underlying amide I protein secondary structure components as well as the NH-OH region. It concluded that the optimum daily administration period of EGb (40 mg/kg) for ophthalmic applications that targeting the retina ranges from 5 to 8 weeks.