Item analysis is the process of collecting, summarizing and using information from students’ responses to assess the quality of test items. Difficulty index (P) and Discrimination index (D) are two parameters which help evaluate the standard of MCQ questions used in an examination, with abnormal values indicating poor quality. In this study, 120 test items of 12 Type A MCQ tests of Foundation 1 multi-disciplinary summative assessment from M2 / 2003 to M2 / 2006 cohorts of International Medical University were selected and their P-scores in percent and D-scores were estimated using Microsoft Office Excel. The relationship between the item difficulty index and discrimination index for each test item was determined by Pearson correlation analysis using SPSS 11.5. Mean difficulty index scores of the individual summative tests were in the range of 64% to 89%. One-third of total test items crossed the difficulty index of 80% indicating that those items were easy for the students. Sixty seven percent of the test items showed acceptable (> 0.2) discrimination index. Forty five out of 120 test items showed excellent discrimination index. Discrimination index correlated poorly with difficulty index (r = -0.325). In conclusion, a consistent level of test difficulty and discrimination indices was maintained from 2003 to 2006 in all the twelve summative type A MCQ tests.
1. The hemorrhagic, procoagulant, anticoagulant, phosphodiesterase, hyaluronidase, alkaline phosphomonoesterase, 5'-nucleotidase, arginine ester hydrolase, phospholipase A, L-amino acid oxidase and protease activities of 30 samples of venoms from nine species (12 taxa) of the old world vipers (Subfamily Viperinae) including snakes from the genera Bitis, Causus, Cerastes, Echis, Eristicophis and Pseudocerastes, were determined and the Sephadex G-75 gel filtration patterns for some of the venoms were also examined. 2. Examination of the biological properties of the venoms of the Viperinae tested indicates the presence of common venom biological characteristics at the various phylogenic levels. 3. Venoms of most species of the Viperinae examined exhibited characteristic biological properties at the species level, and this allows the differentiation of the Viperinae species by differences in their biological properties. 4. Particularly useful for this purpose, are the effects of venom on kaolin-cephalin clotting time of platelet poor rabbit plasma and the Sephadex G-75 gel filtration pattern and arginine ester hydrolase activity of the venom.
1. The biological properties of nine venom samples from six taxa of Micrurus were investigated. The venoms exhibited low protease, phosphodiesterase and 5'-nucleotidase activities, moderate to strong phospholipase A and hyaluronidase activities, variable L-amino acid oxidase activity and were devoid of arginine ester hydrolase and thrombin-like activities. Some venom samples exhibited strong acetylcholinesterase activity. Venoms of M. c. dumerili and M. frontalis exhibited exceptionally high alkaline phosphomonoesterase activity while two of the M. f. fulvius venom samples tested exhibited strong hemorrhagic activity in mice. 2. The polyacrylamide gel electrophoretic patterns of the venoms indicate that most of the Micrurus venom proteins are basic proteins. All Micrurus venoms tested exhibited similar SDS-polyacrylamide gel electrophoretic patterns, with an intense low mol. wt protein band. 3. The Micrurus venoms appear to exhibit biological properties similar to other elapid venoms found in Asia and Africa. There are, however, no common characteristics in the biological properties of the venoms examined at the generic level.
1. The enzymatic, hemorrhagic, procoagulant and anticoagulant activities of venoms of some animals including snakes, lizards, toads, scorpions, spider, wasps, bees and ants were compared. 2. Snake venom was the richest source of enzymes among the animal venoms. Most other animal venoms were devoid of phosphodiesterase, L-amino acid oxidase, alkaline phosphomonoesterase and acetylcholinesterase activities and only a few exhibited arginine ester hydrolase activity. These venoms, however, exhibited wide ranges of protease, 5'-nucleotidase and hyaluronidase activities. Most of the animal venoms examined exhibited some phospholipase A activity. 3. Other than snake venoms, only venoms of the toad Bufo calamita and the lizards were hemorrhagic, and only venoms of the social wasps, social bees and harvester ant exhibited strong anticoagulant activity. Procoagulant activity occurs only in snake venoms.
1. Examination of the polyacrylamide gel electrophoretic (PAGE) and SDS-PAGE patterns of snake venoms shows that these patterns are useful for species differentiation (and hence identification) for snakes of certain genera but have only limited application for snakes from some other genera, due either to the marked individual variations in the venoms or the lack of marked interspecific differences within the same genus. 2. There is no substantial intersubspecific difference in the electrophoretic patterns of the venoms. 3. In general there are no common characteristics in the electrophoretic patterns of the venom at the generic level because of the wide variations in the electrophoretic patterns of venoms of snakes within the same genus. 4. At the familial level, the venoms of Elapidae exhibited SDS-PAGE patterns distinct from those of Crotalidae.
1. The protease, phosphodiesterase, alkaline phosphomonoesterase, L-amino acid oxidase, acetylcholinesterase, phospholipase A, 5'-nucleotidase, hyaluronidase, arginine ester hydrolase, procoagulant, anticoagulant and hemorrhagic activities of ten samples of venoms from seven taxa of sea snakes were examined. 2. The results show that venoms of sea snakes of both subfamilies of Hydrophiinae and Laticaudinae are characterized by a very low level of enzymatic activities, except phospholipase A activity and, for some species, hyaluronidase activity. 3. Because of the low levels of enzymatic activities and the total lack of procoagulant and hemorrhagic activities, venom biological properties are not useful for the differentiation of species of sea snakes. Nevertheless, the unusually low levels of enzymatic activities of sea snake venoms may be used to distinguish sea snake venoms from other elapid or viperid venoms.
1. The hemorrhagic, procoagulant, anticoagulant, protease, arginine ester hydrolase, phosphodiesterase, alkaline phosphomonoesterase, 5'-nucleotidase, hyaluronidase, phospholipase A and L-amino acid oxidase activities of 50 venom samples from 20 taxa of rattlesnake (genera Crotalus and Sistrurus) were examined. 2. The results show that notwithstanding individual variations in the biological activities of Crotalus venoms and the wide ranges of certain biological activities observed, there are some common characteristics at the genus and species levels. 3. The differences in biological activities of the venoms compared can be used for differentiation of the species. Particularly useful for this purpose are the thrombin-like enzyme, protease, arginine ester hydrolase, hemorrhagic and phospholipase A activities and kaolin-cephalin clotting time measurements.
1. The hemorrhagic, procoagulant, anticoagulant, phosphodiesterase, alkaline phosphomonoesterase, 5'-nucleotidase, hyaluronidase, arginine ester hydrolase, phospholipase A, L-amino acid oxidase and protease activities of 26 samples of venoms from 13 species of Bothrops were determined, and the Sephadex G-75 gel filtration patterns for some of the venoms also examined. 2. The results show that while there are considerable individual variations in the biological activities of many of the Bothrops venoms tested, there are some common characteristics at the genus and species levels. 3. The differences in the biological properties of the Bothrops venoms tested can be used for the differentiation of most Bothrops species examined.
1. The hemorrhagic, procoagulant, anticoagulant, phosphodiesterase, alkaline phosphomonoesterase, 5'-nucleotidase, hyaluronidase, arginine ester hydrolase, phospholipase A, L-amino acid oxidase and protease activities of 31 samples of venom from three species of Agkistrodon (A. bilineatus, A. contortrix and A. piscivorus) and 10 venom samples from five other related species belonging to the same tribe of Agkistrodontini were examined. 2. The results indicate that interspecific differences in certain biological activities of the Agkistrodon venoms are more marked than individual variations of the activities, and that these differences can be used for differentiation of the species. Particularly useful for this purpose are the phosphodiesterase, arginine ester hydrolase and anticoagulant activities of the venoms. 3. Venoms of the subspecies of A. contortrix and A. piscivorus do not differ significantly in their biological activities.
1. The hemorrhagic, procoagulant, anticoagulant, phosphodiesterase, hyaluronidase, alkaline phosphomonoesterase, 5'-nucleotidase, arginine ester hydrolase, phospholipase A, L-amino acid oxidase and protease activities of 26 samples of venoms of 13 taxa of Vipera were determined and the Sephadex G-75 gel filtration patterns for some of the venoms were also examined. 2. The results indicate the presence of certain common characteristics among the venoms, particularly if V. russelli is excluded from the comparison. The results also support the recently proposed reassignment of V. russelli to a separate genus. 3. The data show that information on venom biological properties can be used for differentiation of venoms of many species of Vipera. Particularly useful for this purpose are the protease, phosphodiesterase, phospholipase A and the procoagulant activities and the Sephadex G-75 gel filtration patterns of the venoms.
1. The intravenous median lethal doses (LD50), protease, phosphodiesterase, alkaline phosphomonoesterase, L-amino acid oxidase, acetylcholinesterase, phospholipase A, 5'-nucleotidase, hyauronidase and anticoagulant activities of fourteen samples of venoms from the four common species of krait (Bungarus caeruleus, Bungarus candidus, Bungarus multicinctus and Bungarus fasciatus) were examined. 2. The results indicate that even though there are individual variations in the biological properties of the krait venoms, interspecific differences in the properties can be used for differentiation of the venoms from the four species of Bungarus. Particularly useful for this purpose are the LD50's and the contents of 5'-nucleotidase and hyaluronidase of the venoms.
1. The hemorrhagic, procoagulant, anticoagulant, protease, phosphodiesterase, alkaline phosphomonoesterase, L-amino acid oxidase, acetylcholinesterase, arginine ester hydrolase, phospholipase A, 5'-nucleotidase and hyaluronidase activities of 39 samples of venoms from 13 species (15 taxa) of Australian elapids were determined and the Sephadex G-75 gel filtration patterns for some of the venoms were also examined. 2. The results indicate that Australian elapid venoms can be divided into two groups: procoagulant Australian venoms (including N. scutatus, N. ater, O. scutellatus, O. microlepidotus, P. porphyriacus, T. carinatus, H. stephensii and P. textilis) and non-procoagulant Australian venoms (including A. superbus, P. colletti, P. australis, P. guttatus and A. antarcticus). 3. The non-procoagulant Australian venoms exhibited biological properties similar to other elapid venoms, while the procoagulant Australian venoms exhibited some properties characteristic of viperid venoms. 4. The data show that information on venom biological properties can be used for differentiation of many species of Australian elapids. 5. Particularly useful for this purpose are the hyaluronidase, alkaline phosphomonoesterase, acetylcholinesterase, and the procoagulant activities and the Sephadex G-75 gel filtration patterns of the venoms.
Indirect ELISA shows that the antibodies to Calloselasma rhodostoma venom hemorrhagin (CR-HMG), thrombin-like enzyme (CR-TLE) and L-amino acid oxidase (CR-LAAO) exhibited strong to moderate cross-reactions with most crotalid and viperid venoms, but only anti-CR-LAAO cross-reacted with the elapid venoms. However, the indirect ELISA failed to detect some antigenic similarities demonstrable by cross-neutralization study. The double-sandwich ELISA for the three anti-C. rhodostoma venom components exhibited a much lower level of cross-reactions than the indirect ELISA.
1. The biological properties of twelve samples of venoms from all four species of Dendroaspis (mamba) were investigated. 2. Dendroaspis venoms generally exhibited very low levels of protease, phosphodiesterase and alkaline phosphomonoesterase; low to moderately low level of 5'-nucleotidase and very high hyaluronidase activities, but were devoid of L-amino acid oxidase, phospholipase A, acetylcholinesterase and arginine ester hydrolase activities. The unusual feature in venom enzyme content can be used to distinguish Dendroaspis venoms from other snake venoms. 3. All Dendroaspis venoms did not exhibit hemorrhagic or procoagulant activity. Some Dendroaspis venoms, however, exhibited strong anticoagulant activity. The intravenous median lethal dose of the venoms ranged from 0.5 microgram/g mouse to 4.2 micrograms/g mouse. 4. Venom biological activities are not very useful for the differentiation of the Dendroaspis species. The four Dendroaspis venoms, however, can be differentiated by their venom SDS-polyacrylamide gel electrophoretic patterns.
Students' perception of the role and characteristics of a good problem-based learning (PBL) facilitator were assessed in the same study in which students were exposed to the 'Flying a Kite Approach' to PBL. A pre-tested anonymous questionnaire addressed the good qualities of a facilitator as well as the negative aspects. Although faculty and students' perceptions of 'good 'and 'bad' attributes generally agreed, it is clear that students still prefer facilitators who talk more, i.e. explain unclear facts or correct them when their facts are wrong. Content experts are also preferred over non-content experts.
1. The biological properties of venoms from juvenile and adult common tiger snakes (Notechis scutatus) were compared. 2. The lethality, procoagulant activity and enzymatic activities of the juvenile venom were not substantially different from those of the adult venom. 3. Electrophoretic studies, however, indicated some minor differences in the protein composition of the juvenile and adult venoms.
The L-amino acid oxidase of Malayan pit viper (Calloselasma rhodostoma) venom was purified to electrophoretic homogeneity. The molecular weight of the enzyme was 132,000 as determined by Sephadex G-200 gel filtration chromatography and 66,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. It is a glycoprotein, has an isoelectric point of 4.4, and contains 2 mol of flavin mononucleotide per mole of enzyme. The N-terminal amino acid sequence of the enzyme was A-D-D-R-N-P-L-A-E-E-F-Q-E-N-N-Y-E-E-F-L. Kinetic studies suggest the presence of a alkyl side-chain binding site in the enzyme and that the binding site comprises at least four hydrophobic subsites. The characteristics of the binding site differ slightly from those of cobra venom L-amino acid oxidases.
The major hemorrhagin (termed rhodostoxin) of the venom of Calloselasma rhodostoma (Malayan pit viper) was purified to electrophoretic homogeneity by Sephadex G-200 gel filtration followed by high performance ion exchange chromatography. The purified hemorrhagin also yielded a single peak in reversed-phase HPLC. It had an isoelectric point of 5.3 and a mol. wt of 34,000. Rhodostoxin exhibited potent proteolytic, hemorrhagic and edema-inducing activities but was not lethal to mice at a dose of 6 microgram/g (i.v.). Treatment of rhodostoxin with EDTA eliminated both the proteolytic and hemorrhagic activities completely. The N-terminal sequence of rhodostoxin was determined to be NHEIKRHVDIVVVXDSRFCTK.
The biological properties of adult and juvenile inland taipan (Oxyuranus microlepidotus) snake venoms were examined. The enzymatic activities, intravenous median lethal dose and procoagulant activity of the juvenile venom samples were not significantly different from those of the adult venom samples. Also, the juvenile and adult venoms exhibited similar electrophoretic patterns, indicating that they possessed similar protein composition.
The proteolytic specificity of rhodostoxin, the major hemorrhagin from Calloselasma rhodostoma (Malayan pit viper) venom was investigated using oxidized B-chain of bovine insulin as substrate. Six peptide bonds were cleaved: Ser9-Hist10, His10-Leu11, Ala14-Leu15, Tyr16-Leu17, Gly20-Glu21 and Phe24-Phe25. Deglycosylated rhodostoxin, however, cleaved primarily at Arg22-Gly23.