Philippine Journal of Science

Includes bibliographical references.

Isolation and evaluation of antimitotic activity of Phenolic compounds from Pouteria campechiana baehn -- Identification of Cyclospora and Isospora from Diarrheic Patients in the Philippines -- Parameter Estimation on a Model of a Heat-Conducting Rod: Mathematical Analysis and Numerical Computations -- Genetic Diversity of Morus Species of Indigenous and Exotic Accessions Evaluated by Important Agronomical Traits -- A Novel Method for Designing Vaccines Against Constantly Mutating Pathogens -- Layer Chicken Parent Stock Pelleted Litter as Fertilizer in Soybean Production -- Antioxidants of Purple and White Greater Yam (Dioscorea alata L.) Varieties from the Philippines -- Analgesic and Hypoglycemic Activities of Bixa orellana, Kyllinga monocephala, and Luffa acutangula -- Phenotypic and Genotypic Characterization of Bacteria Isolated from Probiotic Dairy Products in the Philippines.

[Article Title : Isolation and evaluation of antimitotic activity of Phenolic compounds from Pouteria campechiana baehni / Christine L.C. Hernandez, Irene M. VIllasenor, Eric Joseph, and Nicola Tolliday, p. 1-10] Abstract : This study was undertaken to determine the compound responsible for the antimitotic activity of ethyl acetate extracts obtained from the leaves of Pouteria campechiana Baehni. Six stilbenes and six flavonoid glycosides were purified and identified after chromatographic separation and spectroscopic analysis. The distilbene ampelopsin B was found to arrest mitosis in a cell-based primary screen to monitor cell-cycle progression and was also determined to be a weak microtubule depolymerizer in a secondary assay.;[Article Title : Identification of Cyclospora and Isospora from Diarrheic Patients in the Philippines / Corazon C. Buerano, Catherine B. Lago, Ronald R. Matias, Blanquita B. de Guzman, Shinji Izumiyama, Kenji Yagita, and Filipinas F. Natividad, p. 11-15] Abstract : In recent years, Cyclospora cayetanensis and Isospora belli have been recognized as causative organisms in cases of chronic diarrhea. The aim of this study was undertaken to determine the prevalence of enteric protozoa among diarrhea patients in the Philippines. Stools were collected and from 3456 samples examined, only one sample each was found positive for oocysts of Cyclospora cayetanensis and Isospora belli. Identification was based on autofluorescence of the oocysts with a 365 nm ultraviolet excitation filter. Both samples were obtained from male patients (18 and 73 years old, respectively) living in Iloilo province in the western islands of Visayas, Philippines. Both patients obtained their drinking water from deep wells. The identification of these two emerging pathogens, which are easily overlooked by less-trained technical staff, highlights the increasing awareness and technical capability on detecting these parasites in the Philippines.;[Article Title : Parameter Estimation on a Model of a Heat-Conducting Rod: Mathematical Analysis and Numerical Computations / Ma. Cristina R. Bargo, Ricardo C.H. del Rosario, and Jose Ernie C. Lope, p. 17-27] Abstract : We model the heat flow of an experiment involving a metallic rod with a heat source at one end. By fitting the mathematical model to experimental data, we were able to estimate the ratios of the rod's thermal conductivity, heat capacity, and flux of the heat source over the heat transfer coefficient. Temperature measurements were obtained via thermocouples located at seven points along the length of the rod. Both steady-state and time-dependent data were used in the parameter estimation, and for the time-dependent case, a numerical algorithm for approximating the partial differential equation was implemented. Since the model featuring realistic boundary conditions does not have an explicit solution, we showed the well-posedness of the model using mathematical analysis. The convergence of the finite-dimensional approximations of the model to the infinite-dimensional solution was also discussed. To solve the optimization problem arising from the parameter estimation problem, we used the least squares and genetic algorithms. Our numerical results indicate that these two optimization algorithms converged to the same solution.;[Article Title : Genetic Diversity of Morus Species of Indigenous and Exotic Accessions Evaluated by Important Agronomical Traits / Amalaendu Ticader and Chandrakana K. Kamble, p. 29-38] Abstract : The genetic diversity and relationship among 50 mulberry germplasm accessions from India and abroad were evaluated for 8 agronomical important traits at Central Sericultural Germplasm Resources Centre (CSGRC), Hosur, Tamil Nadu, India. Significant variations between indigenous and exotic mulberry accessions were observed in different agronomical traits. There were significant variations in 8 agronomic traits among the tested mulberry accessions. Genetic background and environment are the main factors influencing leaf yield. Correlation matrix of different traits showed that leaf yield is a combination of multiple traits and plays a significant role. Ward's minimum variance cluster analysis based on Mahalanobis distances of 8 agronomic traits grouped the indigenous and exotic accessions into 9 clusters. Maximum accessions were grouped in cluster VI and minimum in cluster VIII. The CIMMYT selection indices were employed to group and select the suitable mulberry accessions. Indian accession MI-0416 performed better followed by MI-0376 and Thailand accession ME-0058 than other test germplasm accessions. Both the Indian and exotic accessions have the potential to select and could be important germplasm resources for enriching the genetic background of Indian mulberry accessions through crop improvement program.;[Article Title : A Novel Method for Designing Vaccines Against Constantly Mutating Pathogens / Eduardo A. Padlan, p. 39-51] Abstract : A method is described that could be used to design molecules suitable as vaccines for immunization, or for the generation of therapeutic antibodies against constantly mutating pathogens. The method consists of (1) locating the putative immunodominant epitopes of a protein antigen, and identifying the residues that contribute to the high antigenicity of the epitopes and (2) replacing those residues judiciously to reduce the antigenicity of the immunodominant epitopes, while preserving structure. The antibody response to the modified antigen would then be expected to be directed against more parts of the molecule, and not mainly against the formerly immunodominant epitopes. The method is also useful in the design of molecules suitable for immunization against pathogens that had been intentionally mutated so as to render those pathogens able to infect previously immune individuals.;[Article Title : Layer Chicken Parent Stock Pelleted Litter as Fertilizer in Soybean Production / Tawadchai Suppadit, Laongdown Sangla and Ladda Udompon, p. 53-60] Abstract : Alternative waste management practices need to enhance the safe and economical production of layer chicken parent stock. An appropriate method to enhance safety and benefit is to reuse layer chicken parent stock litter as fertilizer for soybean production. Research was done to study the growth of soybeans, lipid, and protein content in seeds, and heavy metal content in leaves and seeds after the experiment. The experiment was conducted at an artificial housing constructed in Muang district, Ratchaburi province, Thailand from May to September, 2006. The research comprised 6 treatments: pelleted layer chicken parent stock litter (PLCPSL) at rates of 0, 0.02, 0.04, 0.06, 0.08 kg/pot mixture and chemical fertilizer (12 - 24 - 12) at a rate of 0.01 kg/pot were provided to soybean cultivar Chiang Mai 60 (CM. 60).;[Article Title : Antioxidants of Purple and White Greater Yam (Dioscorea alata L.) Varieties from the Philippines / Angelo Josue M. Lubag, Jr., Antonio C. Laurena and Evelyn Mae Tecson-Mendoza, p. 61-67] Abstract : Aqueous methanolic (50% MeOH) extracts of the tubers (peel and flesh) of nine cultivars of greater yam (Dioscorea alata) were determined to have relatively high antioxidant activities among which two cultivars (Ubing upo, purple; LA 096, white) had activities as high as those of a-tocopherol and butylhydroxyanisole (BHA). The aqueous methanol extract of the purple variety was fractionated on XAD-2 column chromatography serially with water, 25% MeOH, 50% MeOH, 75% MeOH, 100% MeOH and acetone. High activities were found in the 50% and 75% MeOH fractions; these were dried and further subjected to semi- or preparative HPLC chromatography using Develosil column. Two major peaks were isolated with high antioxidant activities, P1 and P2. P1 was established to be a purple anthocyanidin with UV-Vis and 1H NMR spectral data that are very similar to alatanin C (Yoshida et al., Tetrahedron Lett. 32: 5579-80 (1991)). Initial results for P2 indicated its phenolic nature with a glucose moiety and a molecular weight of 306. Both P1 and P2 had antioxidant activities higher than those of butylated hydroxyanisole and a-tocopherol.;[Article Title : Analgesic and Hypoglycemic Activities of Bixa orellana, Kyllinga monocephala, and Luffa acutangula / Jusal P. Quanico, Evangeline C. Amor, and Grace C. Perez, p.

69-76] Abstract : The analgesic and hypoglycemic activities of Bixa orellana, Kyllinga monocephala, and Luffa acutangula were evaluated. Methanol extracts of B. orellana and L. acutangula showed significant hypoglycemic activities when administered 15 min after glucose load using a modified oral glucose tolerance test with Swiss Webster mice as test animals. An infusion of B. orellana was found to lower blood glucose level when administered 45 min before glucose load, while that of K. monocephala was found to lower blood glucose level when administered 15 min after glucose load. The methanol extract of K. monocephala was found to significantly reduce the number of writhes in mice administered intraperitoneally with acetic acid to induce abdominal constriction, while those of B. orellana and L. acutangula did not.;[Article Title : Phenotypic and Genotypic Characterization of Bacteria Isolated from Probiotic Dairy Products in the Philippines / Djoko Kisworo, Francisco B. Elegado and Virginia L. Barraquio, p. 77-83] Abstract : Probiotic products that contain live, beneficial microorganisms that provide health benefits have gained popularity among consumers. Fifteen probiotic bacteria were isolated from probiotic dairy products: Chamyto® and Yakult®. All the 14 isolates were Gram positive, catalase negative, rods. One isolate was Gram positive, catalase negative, coccus. The biochemical reaction profiles of 6 selected isolates showed that they were all Lactobacillus paracasei. Their ITS-PCR products showed 65% similarity with Lactobacillus paracasei subsp. paracasei. The 16S rRNA gene sequencing results indicated that the identities of the 3 isolates, 1C10, 2Y9, and 3C10 showed complete (100%) similarity with the 16S rRNA gene of Lb. paracasei. However, 1 isolate, 1Y9, showed 98% similarity with the 16S rRNA gene of Enterococcus faecalis.