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Biomedical subjects

J J Yang

Publications and source records attributed to J J Yang.

At least 109 records · Page 6Linked to original sources
PubMed1993

Simulation of stochastic micropopulation models--I. The SUMMERS simulation shell.

A generic, abstract model and the simulation shell based on it, both called SUMMERS, are used as a framework for the implementation of stochastic micropopulation models; in these, each individual is followed separately while moving through a sequence of states. The shell supports groups of interacting members, individual characteristics and multiple simultaneous activities. Stochastic decisions may be made using Monte Carlo rules. Keywords control the simulations and the reports generated. A sensitivity analysis utility allows assessment of the dependency of outcomes on model features. Extensive use has been made of software engineering techniques. Specializations of SUMMERS are described in subsequent papers.

Data Collection↗
PubMed1993

Simulation of stochastic micropopulation models--II. VESPERS: epidemiological model implementations for spread of viral infections.

This second paper concerning stochastic micropopulation simulations describes VESPERS, which can serve as a framework for simulation models of the epidemic spread of infection. The versions described are implemented using the simulation shell, SUMMERS, which includes the generic commonalities of several micropopulation models. Population members in VESPERS move through states related to the individual's status relative to the infective agent. Features of the models include mixing groups, member demographics, susceptibility and infectiousness, and co-circulation of infectious agents. The sensitivity of the simulation outcomes to quantitative features of the model has been analyzed. The user can select reports of desired distributions and averages of simulation outcomes.

Demography↗
PubMed1993

Parameter sensitivity of a model of viral epidemics simulated with Monte Carlo techniques. I. Illness attack rates.

This is the first of a series of papers concerning sensitivity analyses of stochastic micropopulation models. A model of epidemic spread of viral infection is used in this series to illustrate the principles and performance of the sensitivity analysis system. For these studies the analysis system now known as SENSEN was redesigned and extended to use the principles and modules of the SUMMERS simulation shell. The latter was used in the implementation of the epidemic model as well as a number of others. The SENSEN system can be used with any of these. The advantages of sensitivity analysis for stochastic micropopulation models are discussed. Its general form and operation are illustrated by a comparison of illness attack rates with infection attack rates.

Adult↗
PubMed1993

Evaluation of the anti-inflammatory and liver-protective effects of anoectochilus formosanus, ganoderma lucidum and gynostemma pentaphyllum in rats.

The pharmacological effects of Anoectochilus formosanus, Ganoderma lucidum and Gynostemma pentaphyllum were studied against carrageenan-induced paw edema and CC1(4)-induced hepatotoxicity in rats. The water extracts of G. pentaphyllum and G. lucidum were found to possess significant anti-inflammatory activity against carrageenan induced edema. The administration of Gynostemma pentaphyllum displayed an activity even more potent than indomethacin. In contrast, Anoectochilus formosanus showed a delayed onset of anti-inflammatory activity starting from 4 hrs post carrageenan administration. However, A. formosanus significantly decreased the acute increase in serum GOT and GPT level caused by CC1(4). Histological changes such as necrosis, fatty change, ballooning degeneration, inflammatory infiltration of lymphocytes and Kupffer cells around the central vein were simultaneously improved by the treatment of A. formosanus.

Alanine Transaminase↗
PubMed1992

[Acute purulent pericarditis: clinical experience with primary pericardiectomy plus continuous pericardium lavage].

106 patients with acute purulent pericarditis were treated surgically with three different methods without operative mortality. The pericardiectomy plus continuous pericardial lavage was more effective than pericardiectomy without irrigation or simple pericardial drainage in several aspects, such as recovery of body temperature, elimination of infectious-toxic symptoms and cutting short hospitalization days. Besides, cardiac tamponade or late constriction of the pericardium could be avoided.

Acute Disease↗
PubMed1991

[The structure and absolute configuration of isorupestonic acid from Artemisia rupestris L].

A new sesquiterpene compound named isorupestonic acid was isolated from Artemisia rupestris and its absolute stereostructure was elucidated as 3B by spectral and X-ray crystallographic methods. Interestingly, the isorupestonic acid is based upon an unusual 6, 7 membered ring skeleton differing from the 5, 7 membered ring rupestonic acid although both have the same absolute configuration at C-1. The biogenesis of isorupestonic acid most likely involves breaking the C4-C5 bond of rupestonic skeleton and forming the C5-C14 bond. The absolute configuration of rupestonic acid was also determined as 4C by X-ray analysis and CD data.

Azulenes↗
PubMed1991

[16-Hydroxytriptolide, a new active diterpene isolated from Tripterygium wilford II].

A new diterpene triepoxide, 16-hydroxytriptolide was isolated from the root and leaves of Tripterygium wilfordii Hook.f. 16-Hydroxytriptolide was obtained as white cluster crystal, mp 232-233.5 degrees C. Its molecular formula is C20H24O7. The structure and stereochemistry of 16-hydroxytriptolide was established as L2 on the basis of spectral data (IR, MS, UV, 1H-NMR, 13C-NMR, 2d-NMR, NOE) and X-ray crystallographic analysis. In the pharmacologic screening, 16-hydroxytriptolide showed definite antiinflammatory actions and strong immunosuppressive and antifertile activities. In antiinflammatory action, its half effective dose (ED50) was 0.12 mg/kg with the model of croton oil induced ear swelling of mice. In immunosuppressive action, its ED50 was 0.05 mg/kg with the model of the formation of haemolysinantibody of mice. Its lowest effective dose (po) was 0.027mg/kg x 33d in antifertile action.

Animals↗