Surface-enhanced Raman spectroscopy (SERS) for monitoring colistin-resistant and susceptible E. coli strains.

The emergence of drug-resistant bacteria is a precarious global health concern. In this study, surface-enhanced Raman spectroscopy (SERS) is used to characterize colistin-resistant and susceptible E. coli strains based on their distinguished SERS spectral features for the development of rapid and cost-effective detection and differentiation methods. For this purpose, three colistin-resistant and three colistin susceptible E. coli strains were analyzed by comparing their SERS spectral signatures. Moreover, multivariate data analysis techniques including Principal component analysis (PCA) and Partial Least Squares-Discriminant Analysis (PLS-DA) were used to examine the SERS spectral data of colistin-resistant and susceptible strains. PCA technique was employed for differentiating colistin susceptible and resistant E.coli strains due to alteration in biochemical compositions of the bacterial cell. PLS-DA is employed on SERS spectral data sets for discrimination of these resistant and susceptible E. coli strains with 100% specificity, 100% accuracy, 99.8% sensitivity, and 86% area under receiver operating characteristics (AUROC) curve.

Quantitative analysis of solid dosage forms of Losartan potassium by Raman spectroscopy.

Raman spectroscopy is an outstanding analytical tool increasingly utilized in the pharmaceutical field for the solid-state pharmaceutical drug analysis. In current study, the potential of Raman spectroscopy has been investigated for qualitative and quantitative analysis of solid dosage form of Losartan potassium. For this purpose, different solid dosage forms/concentrations of losartan potassium were prepared to compensate the commercially available pharmaceutical drug formulations and their Raman spectral data showed a gradual change in the specific Raman spectral features associated with the active pharmaceutical ingredient (API) of Losartan potassium as a function of change in the concentration. The Raman spectral data was analyzed by using Principal Component Analysis (PCA) for the classification of different spectral data sets of different concentrations of drug. Moreover, partial least square regression (PLSR) analysis was performed for monitoring the quantitative relation among different concentrations of Losartan potassium API and spectral data by constructing a predictive model. From the model, the value of root mean square error of calibration (RMSEC) and root mean square error of prediction (RMSEP) were observed to be 0.38 and 2.98 respectively and the value of goodness of fit was found to be 0.99. Furthermore, the quantity of unknown/blind sample of Losartan potassium formulation was also estimated by using PLSR model. From these results, it is demonstrated that Raman spectroscopy can be considered to be used for quick and reliable quantitative analysis of pharmaceutical solids.

Application of generated mask method based on Mask R-CNN in classification and detection of melanoma.

OBJECTIVE: Melanoma is a type of malignant skin cancer with high mortality, and its incidence is increasing rapidly in recent years. At present, the best treatment is surgical resection after early diagnosis. However, due to the high visual similarity between melanoma and benign melanocytic nevus, coupled with the scarcity and imbalance of data, traditional methods are difficult to achieve good recognition and detection results. Similarly, many machine learning methods have been applied to the task of skin disease detection and classification. However, the accuracy and sensitivity of the experiments are still not satisfactory. Therefore, this paper proposed a method to identify melanoma more efficiently and accurately. METHOD: We implemented a Mixed Skin Lesion Picture Generate method based on Mask R-CNN (MSLP-MR) to solve the problem of data imbalance. Besides, we designed a melanoma detection framework of Mask-DenseNet+ based on MSLP-MR. This method used Mask R-CNN to introduce the method of mask segmentation, and combined with the idea of ensemble learning to integrate multiple classifiers for weighted prediction. Compared with the ablation experiments, the accuracy, sensitivity and AUC of the proposed network classification are improved by 2.56%, 29.33% and 0.0345. RESULT: The experimental results on the ISIC dataset shown that the accuracy of the algorithm is 90.61%, the sensitivity reaches 78.00%, which is higher than the original methods; the specificity reaches 93.43%; and the AUC reaches 0.9502. CONCLUSION: The method is feasible and effective, and achieves the preliminary goal of melanoma detection. It is greatly improved the detection accuracy and reached the level of visual diagnosis of doctors.

Seizure outcome in moyamoya after indirect revascularization in pediatric patients: Retrospective study and literature review.

BACKGROUND: Moyamoya disease (MMD) is a unique cerebrovascular disorder characterized by progressive stenosis of anterior cerebral circulation. Moyamoya is not an uncommon disease in Saudi Arabia. Although a less common symptom of the disease, the incidence of seizure in MMD ranges from 6 to 30%. Indirect revascularization through Encephaloduroarteriosynangiosis technique is one of the surgical treatment options for MMD. In our cohort, we aim to evaluate seizure outcome in pediatric patients with moyamoya. METHODS: Eleven patients with seizure as primary presentation for MMD over a period of 10 years were included in the study. All patients underwent EDAS surgery. All patients underwent pre- and postoperative assessment of multiple factors contributing to seizure outcome. Patients were evaluated for surgery control clinically and radiologically. RESULTS: About 73% of MMD patients with seizures improved after EDAS surgery (P < 0.0005). Six patients out of 11 became seizure free. Patients with bilateral involvement of disease undergoing bilateral surgery had better seizure control than those undergoing unilateral surgery (P < 0.07). CONCLUSION: Patients with controlled seizure before surgery are more likely to be seizure free after intervention. Seizure outcome is favorable after indirect surgical revascularization in pediatric moyamoya patients.

REVIEW - Advancements in combination therapy of Hepatitis C virus.

Hepatitis C virus (HCV) is a primary cause of chronic liver disease along with various complications like liver cirrhosis and malignancy which leads to death. It has infected more than 185 million people worldwide. There is no congruence established for the treatment of various genotypes of HCV infection owing to diversity in prevalence globally. Assessment of affected individuals with HCV by polymerase chain reaction (PCR), viral load of HCV and liver enzyme levels (i.e., ALT and AST) are the foundation to evaluate the safety and efficacy of HCV therapies. The antiviral efficacy has been greatly improved and sustained viral response (SVR) rates increased from 6% with interferon monotherapy to 50-80% with PEG-interferon/ribavirin combination therapy to >95% after the approval of all interferon free oral direct acting antiviral agents. The main objective of this review article is to compile data from reference sources regarding the old and current therapeutic strategies used to manage HCV infection. It is accepted that chronic HCV infection increases patient's thrombocytopenia and neutropenia risk and complications increased in co-morbid disorders like in tuberculosis, HIV, diabetes etc. In past treatment associated side effects were the major consequences and many patients have to stop the treatment. But after the approval of direct acting antiviral drugs create a revolution in the treatment of HCV infection. So, it could be concluded that current combination therapies are a promising hope to eradicate and to control HCV but some safety concerns required more considerations Therefore, this review focus on the available latest combination therapies and their effectiveness to eradicate HCV infection.

Pronounced Impact of p-Type Carriers and Reduction of Bandgap in Semiconducting ZnTe Thin Films by Cu Doping for Intermediate Buffer Layer in Heterojunction Solar Cells.

Stabilized un-doped Zinc Telluride (ZnTe) thin films were grown on glass substrates under vacuum using a closed space sublimation (CSS) technique. A dilute copper nitrate solution (0.1/100 mL) was prepared for copper doping, known as an ion exchange process, in the matrix of the ZnTe thin film. The reproducible polycrystalline cubic structure of undoped and the Cu doped ZnTe thin films with preferred orientation (111) was confirmed by X-rays diffraction (XRD) technique. Lattice parameter analyses verified the expansion of unit cell volume after incorporation of Cu species into ZnTe thin films samples. The micrographs of scanning electron microscopy (SEM) were used to measure the variation in crystal sizes of samples. The energy dispersive X-rays were used to validate the elemental composition of undoped and Cu-doped ZnTe thin films. The bandgap energy 2.24 eV of the ZnTe thin film decreased after doping Cu to 2.20 eV and may be due to the introduction of acceptors states near to valance band. Optical studies showed that refractive index was measured from 2.18 to 3.24, whereas thicknesses varied between 220 nm to 320 nm for un-doped and Cu doped ZnTe thin film, respectively, using the Swanepoel model. The oxidation states of Zn+2, Te+2, and Cu+1 through high resolution X-ray photoelectron spectroscopy (XPS) analyses was observed. The resistivity of thin films changed from ~107 Ω·cm or undoped ZnTe to ~1 Ω·cm for Cu-doped ZnTe thin film, whereas p-type carrier concentration increased from 4 × 109 cm-2 to 1.4 × 1011 cm-2, respectively. These results predicted that Cu-doped ZnTe thin film can be used as an ideal, efficient, and stable intermediate layer between metallic and absorber back contact for the heterojunction thin film solar cell technology.

Evaluation of antibiotic use in Pediatric Intensive Care Unit of a developing country.

BACKGROUND: Pediatric Intensive Care Unit (PICU) patients are often prescribed antibiotics with a low threshold in comparison to patients elsewhere. Irrational antibiotics use can lead to rapid emergence of drug resistance, so surveillance of their use is important. OBJECTIVES: To evaluate the use of antibiotics in relation to bacteriological findings in PICU of a Tertiary Hospital. METHODS: Retrospective review of medical records of all children (age 1 month-16 years) admitted in our closed multidisciplinary-cardiothoracic PICU from January to June 2013 was performed, after approval from Ethical Review Committee. For each antibiotic, indication (prophylactic, empiric, therapeutic) and duration of use were recorded. All diagnoses of infections were recorded according to diagnostic criteria of IPSCC 2005. Results are presented as frequency and percentages and median with inter quartile range using SPSS version 19. RESULTS: All of the total 240 patients admitted in PICU during the study period received antibiotics: 43% (n = 104) prophylactically, 42% (n = 102) empirically, and 15% (n = 15) therapeutically. Median number of antibiotic use per patient in PICU was 3, with range of 1-7. 25% received 1 antibiotic, 23% received 2 antibiotics, 29% received 3 antibiotics, and rest received ≥4 antibiotics. Most commonly used antibiotics were cefazolin, meropenem, vancomycin and ceftriaxone, and most frequently used combination was meropenem and vancomycin. In majority of the cases, (70%) empiric antibiotic combinations were stopped in 72 h. CONCLUSION: This is the first report of antibiotics use in PICU from our country, which shows that antibiotics are prescribed universally in our PICU. Strategies to assess the need for antibiotic use are needed.

Rectal Duplication Cyst: A Rare Cause of Rectal Prolapse in a Toddler.

Rectal duplication cysts are rare congenital anomalies. They constitute only 4% of the total gastrointestinal anomalies. They usually present in childhood. The common presenting symptoms are mass or pressure effects like constipation, tenesmus, urinary retention, local infection or bleeding due to presence of ectopic gastric mucosa. We are reporting a rare presenting symptom of rectal duplication cyst in a 4-year-old boy/toddler who presented with rectal prolapse. He also had bleeding per rectum. Rectal examination revealed a soft mass palpable in the posterior rectal wall. CT scan showed a cystic mass in the posterior wall of the rectum. It was excised trans-anally and the postoperative recovery was uneventful. Biopsy report showed rectal duplication cyst.

FREQUENCY OF HOSPITAL ACQUIRED HYPONATREMIA IN A PEDIATRIC TERTIARY CARE SETTING.

BACKGROUND: Hyponatremia is the most commonly encountered electrolyte disorder in children. In our country the epidemiology of hospital acquired hyponatremia has hardly ever been explored whereas the administration of hypotonic IV fluids is widely practiced here. Therefore we pioneered to conduct this study to determine the frequency of hospital acquired hyponatremia. METHODS: This was a cross sectional study carried out at Aga Khan University Hospital, Karachi in paediatric ward and ICU over a period of 12 months. All children (>1 month and <15 years of age) admitted in paediatric units and on maintenance IV fluids who had serum sodium level measured on admission were included in the study and followed to identify patients who had a drop in serum sodium during hospitalization. Informed consent was taken from parents and collected data was recorded on a pro forma. RESULTS: A total of 865 patients were enrolled in the study. Hyponatremia was recorded in 405 patients on admission (46.8%) while hospital acquired hyponatremia was documented in 240. children (27.7%). Out of these 142 (59.2%) were male and 98 (40.8%) were female. Mean age of children in hospital acquired hyponatremia group was 60.67 months. Severity of hospital acquired hyponatremia was recorded as mild in 191 (79.6%), moderate in 35 (14.6%) and severe in 14 (5.8%) children. Major disease categories included gastrointestinal disorder (30.4 %), respiratory illness (12.5%), oncological disease (16.3%), cardiovascular disease (11.7%), infectious disease (9.2%) and neurological illness (8.3%). CONCLUSION: Hospital acquired hyponatremia is frequently encountered in our hospitalized children with majority of them receiving hypotonic IV solutions.

REVISED TRAUMA SCORE AS A PREDICTOR OF OUTCOME IN TRAUMA CASES: EXPERIENCES AT A TERTIARY CARE HOSPITAL IN KARACHI, PAKISTAN.

BACKGROUND: Trauma scores help classify trauma patients, and assist in clinical decision-making. The Revised Trauma Score (RTS) is widely used internationally but its effectiveness as a tool for predicting outcome in paediatric trauma patients in our setting, has yet to be established, mainly owing to lack of use. The aim of this study was to determine the effectiveness of RTS as a predictor of outcome in paediatric trauma patients in Pakistan. METHODS: We conducted a retrospective review of patient medical records at Aga Khan University Hospital, Karachi, from October 2006 to October 2009 and all patients aged less than 14 years, presenting with trauma were selected. Information was collected regarding demographics, vital signs at the time of presentation, length of stay (LOS) in the ward, ICU and the hospital, complications during hospital stay and mortality. Data was analysed in SPSS-17.0. RESULTS: The sample was 501 patients with a mean age of 5.3 years. Two third (66%) were males and 34% were females. Using available data, RTS was calculated for 394 patients, who were then divided into two groups based on the RTS. For 32 patients with a RTS less than 10, the length of stay in the ward, ICU and the hospital were all shorter than the 363 patients with a RTS greater than 10 (p-value <0.001). CONCLUSION: In our setting, RTS is a good predictor of outcome in paediatric trauma patients. It can aid in the assessment of severity of injury in, and objective assessment and triaging of paediatric trauma patients.

Production of rhamnolipid surfactant and its application in bioscouring of cotton fabric.

In the present study, a biosurfactant was synthesized by using a bacterial strain of Pseudomonas aeruginosa in minimal media provided with n-heptadecane as sole carbon source under shake-flask conditions. The biosurfactant was isolated (by acid precipitation, solvent extraction, and rotary evaporation), purified (by column chromatography and TLC), identified (by FAB-MS, FTIR, and 1D-(1)H NMR), and chemo-physical characterized (by tensiometry). Two principal rhamnolipid congeners were identified as dirhamnolipid RRC10C10 and monorhamnolipid RC10C10 with a CMC of 50mg/L. The biosurfactant, hence produced, was applied in sole and in combination with pectinase in scouring of cotton fabric in contrast to conventional scouring agents of NaOH and anionic surfactant SDS. The scoured cotton fabric was investigated for its weight loss, residual oil and grease, wettability, whiteness, and tensile strength. The results were compared both for conventional and biological approaches. The scouring with biosurfactant plus pectinase was equivalent to or better in efficiency than conventional alkaline scouring. The former process is additionally environmentally friendly and bio-compatible. Scanning electron microscopy of cotton fabric showed that the alkaline scouring deteriorates the fabric texture whereas bioscouring with biosurfactant plus pectinase gently removes hydrophobic impurities from the cotton fabric.

Ventriculoperitoneal shunt peritoneal catheter knot formation.

The ventriculoperitoneal (VP) shunt is a common procedure in pediatric neurosurgery that carries a risk of complications at cranial and abdominal sites. We report on the case of a child with shunt infection and malfunction. The peritoneal catheter was tethered within the abdominal cavity, precluding its removal. Subsequently, laparoscopic exploration identified a knot at the distal end of the peritoneal catheter around the omentum. A new VP shunt was inserted after the infection was healed. This type of complication occurs rarely, so there are a limited number of case reports in the literature. This report is complemented by a literature review.

Deficiency of ADAMTS-13 in pediatric patients with severe sepsis and impact on in-hospital mortality.

BACKGROUND: The enzyme involved in regulating the size of vWF (von Willebrand factor) in plasma is ADAMTS-13 (A disintegrin and metalloprotease with thrombospondin type-1 motives). Deficient proteolysis of ULvWF (ultra large von Willebrand factor) due to reduced ADAMTS-13 activity results in disseminated platelet-rich thrombi in the microcirculation characteristic of thrombotic thrombocytopenic purpura. Reduced ADAMTS-13 has also been observed in severe sepsis and is associated with poor survival. We conducted this study to detect ADAMTS-13 deficiency and its impact on in-hospital mortality in pediatric patients with severe sepsis. METHODS: Pediatric patients diagnosed with severe sepsis were recruited for the study. Baseline clinical characteristics were noted. ADAMTS-13 antigen levels were assayed by ELISA. According to ADAMTS-13 levels, patients were grouped as deficient and non-deficient. Comparison was done with regard to some clinical and biological characteristics and in-hospital mortality between the two groups. RESULTS: A total of 80 patients were enrolled in the study. The median age of the patients was 3.1 years (Range: 0.1-15 years). ADAMTS-13 deficiency with levels less than 350 ng/dl was found in 65% patients. In patients with ADAMTS-13 deficiency, 75.6% had low platelets of less than 150 × 109/L. In-hospital mortality was 42.3% and 35.7% in ADAMTS-13 deficient and non-deficient group, respectively. CONCLUSION: Majority of the pediatric patients admitted to hospital with severe sepsis exhibit ADAMTS-13 deficiency. ADAMTS-13 deficiency might play a role in sepsis-induced thrombocytopenia. More studies are needed to evaluate the role of ADAMTS-13 deficiency on in-hospital mortality.

Cauda equina syndrome as the initial presenting clinical feature of medulloblastoma: a case report.

INTRODUCTION: Medulloblastoma is one of the most common pediatric brain malignancies. The usual presenting clinical features are related to posterior fossa syndrome or/and hydrocephalus. Cauda equina syndrome is a very rare presentation for this disease. CASE PRESENTATION: We describe the case of a three-year-old boy with cauda equina syndrome as the initial presenting clinical feature for medulloblastoma. He was initially diagnosed as having a spinal tumor by magnetic resonance imaging scan. Subsequently, a cranial magnetic resonance imaging scan revealed a posterior fossa tumor with features of dissemination. He had substantial improvement after treatment. This case report is complemented by a literature review related to this unusual presentation. CONCLUSIONS: Medulloblastoma primarily presenting with cauda equina syndrome is very rare. However, spinal drop metastasis should be considered in the pediatric age group to avoid suboptimal management.

Effects of solvation on the spin state of iron(III) in 2,8,12,18-tetrabutyl-3,7,13,17-tetramethyl-5,10-diazaporphyrinatoiron(III) chloride.

The chloroiron(III) complex of 2,8,12,18-tetrabutyl-3,7,13,17-tetramethyl-5,10-diazaporphyrin, [(Cl)FeMBDAP], was prepared and studied by X-ray crystallography and by solution (1)H NMR and UV-vis measurements. In the crystal structure of hemisolvate [(Cl)FeMBDAP] x 0.5CHCl(3), two nonequivalent [(Cl)FeMBDAP] units containing Fe1 and Fe2 are arranged in pi-dimers with considerable overlap on their concave sides. Axial chloride bonded to Fe2 is solvated by hydrogen bonding with CHCl(3). Parameters of the coordination pyramid have typical values for the spin-mixed (S = 3/2 / 5/2) Fe(III) complexes in the case of Fe1 and are characteristic for the pure intermediate-spin state for Fe2 (displacement from the (N(Pyr))(4) planes - 0.385 and 0.290 A and the average N(Pyr)-Fe bond lengths -1.992 and 1.954 A for Fe1 and Fe2, respectively). Effective magnetic moments in CHCl(3) and CH(2)Cl(2) capable of specific solvation of chloride by hydrogen bonding (4.5-4.6 micro(B) at 298 K) are indicative about mixed intermediate/high-spin state S = 3/2 / 5/2, with the S = 3/2 contribution increasing upon lowering of the temperature (4.02 micro(B) in CD(2)Cl(2) at 193 K). In nonsolvating CCl(4), C(6)D(6), and THF-d(8), the mu(eff) values are consistent with the predominantly high-spin state at ambient temperature (5.5-5.75 micro(B) at 298 K) and almost pure S = 5/2 state at low temperature (ca. 5.9 micro(B) in THF-d(8) below 270 K). Downfield isotropic shifts from 35 to 50 ppm are observed for alpha-alkyl protons and upfield shifts from -5 to -15 ppm for meso-CH protons, which is characteristic for the presence of the intermediate-spin state. The splitting of signals of the diastereotopic alpha-CH(2) protons is increased with growth of the S = 3/2 state contribution from 1.5 to 4 ppm in nonsolvating to 11 ppm in specifically solvating solvents at 298 K and further to 31 ppm at 193 K (in CD(2)Cl(2)). In the presence of DMSO addition and in methanol solution, the single CH(2) signal is observed at 25-28 ppm, and the meso-CH resonance is also shifted downfield to ca. 30 ppm, indicating the formation of six-coordinated complexes [(DMSO)(2)FeMBDAP](+) and [(MeOH)(2)FeMBDAP](+), the latter having the mu(eff) value of 4.92 micro(B) at 291 K is a spin-mixed species. The electron spin resonance spectra recorded at 77 K indicates that in frozen glasses in CD(2)Cl(2) and THF molecules in the high-spin state (g( perpendicular) approximately 6) and the predominantly intermediate-spin state (g( perpendicular) approximately 4.2-4.3) coexist together.

Pulmonary embolism secondary to clozapine therapy.

Clozapine is an atypical antipsychotic indicated for paranoid schizophrenia (treatment resistant type). However its use has been limited by the well established association with neutropenia and agranulocytosis. It has also been suggested that clozapine therapy is associated with other serious adverse effects such as fatal myocarditis or cardiomyopathy.

Comparison of in-house-developed ELISA with HPLC techniques for the analysis of atrazine residues.

In-house developed ELISA was standardized to monitor atrazine residues in different environmental samples. The standard curve was linear, indicating an increase in log concentration with decrease in absorbance (%B/B(0)=1.075-0.042 Log C; r= -0.966). The middle of the test was at 75 ng/L and the lowest detection limit at 4 ng/L. ELISA significantly correlated with the high performance liquid chromatography (HPLC) (r=0.990). Internal validation showed good accuracy and precision. Maximum atrazine residues were present in Jehlum River water/sediments and maize/sugarcane plant roots. Most of the food samples were found to be contaminated. ELISA required less clean-up steps than HPLC, but showed matrix effect in soil/colored extracts.

Oesophageal replacement in children with indolent stricture of the oesophagus.

OBJECTIVE: To evaluate the indications for and results of oesophageal replacement for acquired oesophageal stricture in children. METHODS: This was a descriptive interventional study. Between 1987 and 2003, patients who had peptic or corrosive stricture were included in the study. Age and gender were analysed and any history of ingestion of caustic agents or untreated reflux was noted. Types of symptoms such as progressive dysphagia to solids and liquids and extent of respiratory infections were evaluated. Nutritional deprivation was also measured. Success or failure of dilatation at the time of endoscopy was taken into account. The criterion for oesophageal replacement was recurrence of stricture within 3 weeks of the previous dilatation. Patients were prepared with general supportive care. Feeding gastrostomy was performed in 12 patients who were severely malnourished. No patients underwent oesophagectomy of the strictured oesophagus. Short- and long-term complications were recorded. RESULTS: Of the 54 patients, 34 were male and 20 were female. Colonic conduit and reverse gastric tube were used in 27 patients each. Three patients had leak and were treated conservatively. Six patients developed anastomotic stricture but benefited remarkably from periodic dilatation and, in the long-term, remained symptom-free. Results were generally very gratifying. CONCLUSION: Most patients who require oesophageal conduit do well and catch up with their growth and development.