Optimum Temperature and Thermal Stability of Crude Polyphenol Oxidase from some Common Fruits

The effect of temperature on the activity and thermal stability of crude polyphenol oxidase (PPO) extracted from garden egg (Solanum aethiopicum), pawpaw (Carica papaya), pumpkin (Cucurbita pepo), guava (Psidium guajava) and bush mango (Irvingia gabonnensis) fruits were studied using 20 mM Catechol solution as a substrate. The optimum temperature was found to be 30oC for the enzyme extracted from guava, 40oC for that extracted from both pawpaw and pumpkin and 50oC for that from both garden egg and bush mango. The PPO extracted from all the fruits is stable upon incubation for 10 to 120 minutes at temperature between 20- 70oC. The activity of the crude enzyme from all the fruits used was found to decrease at various degrees after incubation for 10 to 120 minutes at temperature greater than 70oC. Therefore increasing the incubation temperature above 70oC would cause decrease in the activity of the enzyme and can be a good method of controlling undesirable changes caused by the enzyme in the products of these fruits

Isolation, characterization and antimicrobial study of lupeol acetate from the root bark of Fig-Mulberry Sycamore (Ficus sycomorus LINN)

The phytochemical investigation of n-butanolic extract from the root bark of Ficus sycomorus using microwave-assisted extraction revealed the presence of steroids, triterpenes, flavonoids, alkaloids, and tannins. Detailed chromatographic techniques on the extract led to the isolation of a triterpenoid compound for the first time from the part of the plant, which was identified as lupeol acetate by chemical and spectroscopic studies. Antimicrobial activity study of the isolated compound on some selected microorganisms showed that the compound is a potential source of antibiotic agents.Keywords: Antimicrobial, Ficus sycomorus, lupeol acetate, root bar

Optimum pH and pH Stability of Crude Polyphenol Oxidase (PPO) Extracted from Five Fruit Samples Commonly Consumed in Kano State, Nigeria

The effect of pH on the activity and stability of crude polyphenol oxidase (PPO) extracted from garden egg (Solanum aethiopicum), pawpaw (Carica papaya), pumpkin (Cucurbita pepo), guava (Psidium guajava) and bush mango (Irvingia gabonnensis) fruits were studied. Catechol at concentration of 20 mM was used as a substrate while sodium acetate buffer (0.2 M), pH range between 3.0– 5.5 and sodium phosphate buffer(0.2 M) , pH range between 6.0– 8.5 were used to determine the effect of pH on the PPO activity. Optimum pH values were found to be 6.0,6.5,6.0, 4.5 and 4.0/or 8.0 for the enzyme extracted from Solanum aethiopicum, Carica papaya, Cucurbita pepo, Psidium guajava and Irvingia gabonnensis respectively. The enzyme was found to be stable at the pH range of 5.0-7.5 for the enzyme extracted from garden egg, 6.0-8.0 for that from pawpaw, 4.5-7.0 for that from pumpkin, 4.0-6.5 for that from guava and 3.5-5.5 and 7.0-8.0 for that from bush mango respectively. Increase or decrease of pH from the ranges would cause decrease in the activity of the enzyme, and can be a good way of controlling undesirable changes caused by it in foods. Keywords: Optimum pH, pH stability, Polyphenol oxidase, Common fruits

Correlation and path coefficient analysis of yield and agronomic characters among open pollinated maize varieties and their F1 hybrids in a diallel cross

A two-year study was conducted on maize (Zea mays L.) at the University of Ilorin Teaching and Research Farm Ilorin, Nigeria, during 2005 and 2006 growing seasons. The objective was to investigate correlation between grain yield and other agronomic parameters using 10 open-pollinated maize varieties and their 45 F1 hybrids in a half diallel. Positive and significant phenotypic and genotypic correlations were found for days to 50% tasselling with plant and ear height, and grain yield with plant height, number of grains ear-1 and ear weight. Positive and significant environmental correlation was also recorded for grain yield with plant and ear height, and ear weight. The path analysis revealed that, days to 50% silking, ear weight and number of grains ear-1 had the highest direct effect on grain yield, while number of grains ear-1 had the highest moderate indirect negative effects on grain yield. Days to flowering, plant and ear height, number of grains ear-1 and ear weight could be the important selection criteria in improving open pollinated maize varieties and hybrids for high grain yield

Social, economic and psychological burdens of sickle cell disease care among households of sufferers in a tertiary health facility in North Western Nigeria

The study assessed the social, economic and psychological burden of sickle cell disease (SCD) care among households of SCD patients attending sickle cell outpatient clinic in Ahmadu Bello University Teaching Hospital, Zaria, Nigeria. Methods: It was a cross-sectional descriptive study conducted among 205 caregivers of SCD outpatients selected through systematic sampling. Data was collected using a structured interviewer-administered questionnaire, and analyzed using the IBM SPSS version 20.0 Results: The mean age of the SCD patients was 12.7±9.0 years and their mean duration since diagnosis was 10.9±8.7 years. In the last 12 months, 92 (44.9%) patients had been admitted at least once due to complications of SCD, 72 (35.1%) had been transfused with blood and 150 (73.1%) had experienced painful crises. Caring for SCD patients frequently reduces the amount of care that other household members were receiving 95 (46.3%), patient's illness frequently caused disagreement or quarrel among household members 150 (73.2%), and households experienced stigmatization by community members 33 (16.1%). Ninety-six (71.2%) of the households were experiencing catastrophic expenditure from providing medical care for the SCD patient. Conclusion: Households of SCD patients were experiencing various forms of psychological, social and economic burden. It is recommended that locally applicable methods of psychological, social and economic support be included in the routine care of SCD patients and their families

Renal diseases: caregivers' knowledge, attitude and practice in North Eastern Nigeria

Lack of awareness of renal diseases among the parents/ care givers of children can contribute to the development of childhood chronic kidney disease (CKD). Awareness of kidney disease by the care givers of children can improve their health seeking behaviour and reduce the significant economic and public health burden. We conducted a cross-sectional descriptive study to assess the knowledge, attitude and practice of renal diseases among the care givers of children attending University of Maiduguri Teaching Hospital. Management of CKD is very expensive especially in the third world where most care givers are poor and cannot afford the cost of renal replacement therapy like dialysis and renal transplant. This underscores the determination of knowledge, attitude and practice of parents/ care givers on childhood renal diseases. Objective: To assess the knowledge, attitude and practices on renal diseases among the care givers of children attending a tertiary hospital in north eastern Nigeria. Method: This cross-sectional study was conducted among mothers or caregivers of children receiving care in the department of Paediatrics of a Teaching Hospital, Borno state. Mothers/ caregivers were consecutively selected as they come to the hospital and 420 subjects were interviewed through a self-administered questionnaire. Each subject was interviewed on his or her knowledge, attitude and practice of childhood renal diseases and data was entered appropriately into the different sections of the study questionnaires. Data was analysed using Epi-info statistical software (version 7.0). Informed consent was obtained from the parents and confidentiality to any information disclosed by the mother was ensured. Results: The ages of the respondents ranged from 18 – 67 years with amean age of 37.2 (SD±13.6) years. Majority 140 (33.3%) of the respondents were aged 31 – 50 years; p<0.05. Among the respondents, were 255 (60.7%) females and 165 (39.3%) males with male to female ratio of 1: 1.5. The ages of the children ranged from 1 month to 15 years with 239 (56.9%) males and 181 (43.1%) females and male to female ratio of 1.3: 1. There were 267 (63.6%) Muslims and 153 (36.4%) Christians. There were 98 (23.3%) care givers from the upper social class, 120 (28.6%) from the middle social class and 202 (48.1%) from the lower social class. Most mothers (89.2%) had no factor preventing them from seeking medical care. Many (70.7%) of the caregivers took their children to health facilities once sick or developed any symptom of severe childhood disease. Conclusion: Although most of the care givers that participated in this study had knowledge of one form of kidney disease or the other, most had no knowledge of any treatment modality of these kidney diseases

Micro-Fluidic Diffusion Coefficient Measurement

A new method for diffusion coefficient measurement applicable to micro-fluidics is pre- sented. The method Iltilizes an analytical model describing laminar dispersion in rect- anglllar ~llicro_channe]s. The Illethod ~vas verified throllgh measllremen~ of fllloresceill diffusivity in water and aqueolls polymer solutions of differing concentration. The diffll- sivity of flllorescein was measlmed as 0.64 x 10-gm2/s in water, 0.49 x 10-gm2/s in the 4 gm/dl dextran solution and 0.38 x 10-9n12/s in the 8 gnl/dl dextran solution

Insulin gene VNTR genotype associates with frequency and phenotype of the autoimmune response to proinsulin

Immune responses to autoantigens are in part controlled by deletion of autoreactive cells through genetically regulated selection mechanisms. We have directly analyzed peripheral CD4+ proinsulin (PI) 76–90 (SLQPLALEGSLQKRG)-specific T cells using soluble fluorescent major histocompatibility complex class II tetramers. Subjects with type I diabetes and healthy controls with high levels of peripheral proinsulin-specific T cells were characterized by the presence of a disease-susceptible polymorphism in the insulin variable number of tandem repeats (INS-VNTR) gene. Conversely, subjects with a ‘protective' polymorphism in the INS-VNTR gene had nearly undetectable levels of proinsulin tetramer-positive T cells. These results strongly imply a direct relationship between genetic control of autoantigen expression and peripheral autoreactivity, in which proinsulin genotype restricts the quantity and quality of the potential T-cell response. Using a modified tetramer to isolate low-avidity proinsulin-specific T cells from subjects with the susceptible genotype, transcript arrays identified several induced pro-apoptotic genes in the control, but not diabetic subjects, likely representing a second peripheral mechanism for maintenance of tolerance to self antigens

Observation of Electron-Hole Puddles in Graphene Using a Scanning Single Electron Transistor

The electronic density of states of graphene is equivalent to that of relativistic electrons. In the absence of disorder or external doping the Fermi energy lies at the Dirac point where the density of states vanishes. Although transport measurements at high carrier densities indicate rather high mobilities, many questions pertaining to disorder remain unanswered. In particular, it has been argued theoretically, that when the average carrier density is zero, the inescapable presence of disorder will lead to electron and hole puddles with equal probability. In this work, we use a scanning single electron transistor to image the carrier density landscape of graphene in the vicinity of the neutrality point. Our results clearly show the electron-hole puddles expected theoretically. In addition, our measurement technique enables to determine locally the density of states in graphene. In contrast to previously studied massive two dimensional electron systems, the kinetic contribution to the density of states accounts quantitatively for the measured signal. Our results suggests that exchange and correlation effects are either weak or have canceling contributions.Comment: 13 pages, 5 figure

Anti-Angiogenic Therapy Induces Integrin-Linked Kinase 1 Up-Regulation in a Mouse Model of Glioblastoma

BACKGROUND: In order to improve our understanding of the molecular pathways that mediate tumor proliferation and angiogenesis, and to evaluate the biological response to anti-angiogenic therapy, we analyzed the changes in the protein profile of glioblastoma in response to treatment with recombinant human Platelet Factor 4-DLR mutated protein (PF4-DLR), an inhibitor of angiogenesis. METHODOLOGY/PRINCIPAL FINDINGS: U87-derived experimental glioblastomas were grown in the brain of xenografted nude mice, treated with PF4-DLR, and processed for proteomic analysis. More than fifty proteins were differentially expressed in response to PF4-DLR treatment. Among them, integrin-linked kinase 1 (ILK1) signaling pathway was first down-regulated but then up-regulated after treatment for prolonged period. The activity of PF4-DLR can be increased by simultaneously treating mice orthotopically implanted with glioblastomas, with ILK1-specific siRNA. As ILK1 is related to malignant progression and a poor prognosis in various types of tumors, we measured ILK1 expression in human glioblastomas, astrocytomas and oligodendrogliomas, and found that it varied widely; however, a high level of ILK1 expression was correlated to a poor prognosis. CONCLUSIONS/SIGNIFICANCE: Our results suggest that identifying the molecular pathways induced by anti-angiogenic therapies may help the development of combinatorial treatment strategies that increase the therapeutic efficacy of angiogenesis inhibitors by association with specific agents that disrupt signaling in tumor cells