Murder by Poisons: Cases in Taiwan, 1999-2008.

This review summarizes the findings from a retrospective study of 17,390 forensic autopsy cases of medicolegal investigations in Taiwan during the 1999-2008 period. Among this total, 1,874 cases involved illicit drugs and 750 involved household toxic chemicals. Rarely seen toxic substances, such as cyanide, corrosive poisons, ether, etc., were found in 6.4%percent; of homicide poisoning cases. Profiling the suspects' backgrounds may play a key role in correlating unique chemicals with the suspects' homicidal behavior.

Human methamphetamine-related fatalities in Taiwan during 1991-1996.

Methamphetamine (MAP) is currently considered to be the major illicit drug in Taiwan, and MAP constitutes the majority of illicit drugs seized by the judicial institutes. Thus, MAP has raised public attention. The purpose of this retrospective study is to observe the trends of MAP-related fatalities in Taiwan with respect to the manners of death so as to determine the epidemiological implications of MAP. Two hundred and forty-four MAP-related fatalities out of a total of 3958 forensic fatalities were collected by the Forensic Medicine Center (Taiwan) during the period of 1991 to 1996. The annual percentages of MAP-related fatalities compared to the total autopsy cases during 1991 through 1996 were 3.4, 10.3, 12.1, 4.2, 4.0 and 5.6%, showing that the number of MAP-related fatalities increased from 1991 to 1993, declined during 1994 and 1995, and rose again in 1996. The mean age of the MAP-related fatalities during this period was 30.7 years and occurred predominantly in males (73%). The manner of deaths included natural, accidental, suicidal, homicidal and uncertain causes of deaths, represented, respectively, by 31 (13%), 143 (59%), 28 (11%), 34 (14%) and 8 (3%) cases. As a consequence of the endemic problem and public hazard created by illicit drug abuse in Taiwan, stronger anti-drug programs and curbs to illicit-drug addiction were required urgently from the government and from the public. The findings of this study represent the results of utilization of an anti-drug program in Taiwan (Support by NSC 85-2331-B-016-092).

Origin of innervation in the feline ophthalmic artery.

In this study, we investigate the innervation to the feline ophthalmic artery by the horseradish peroxidase (HRP) tracing method. Five adult cats with body weights ranging between 2.0 and 3.0 kg were used. Under microscopic dissection, the ophthalmic artery was identified and isolated. A gelfoam (Upjohn Co.), 1 x 3 mm in size, containing 0.1 ml of HRP was applied to the prepared artery segment for 2 h. The cat was sacrificed 3 days later. The trigeminal, stellate, superior cervical, middle cervical and nodal ganglia, and oculomotor, trochlear and abducens nuclei were removed, sectioned and stained for HRP-positive cells. HRP-labeled neurons were found in the ipsilateral trigeminal (TRG) and superior cervical ganglia (SCG). The middle cervical, stellate, Edinger-Westphal, trochlear and abducens nuclei were all deemed negative for HRP-labeled cells. In the TRG, HRP-labeled neurons ranged from 21 to 250 (mean +/- SE = 93.8 +/- 42.5/ganglion). The labeled neurons were distributed primarily in the ophthalmic branch. In the SCG, the HRP-labeled neurons were distributed evenly in the ganglion, ranging from 6 to 180 (mean +/- SE = 91.6 +/- 31.5/ganglion). Two additional cats having received a sham operation revealed a negative finding. The feline ophthalmic artery is innervated by the ipsilateral TRG and SCG. Such innervation may play a role in regulating blood flow to the optic nerve.

Horizontal distance and height determining falling pattern.

Falling from a height, usually from a building, occurs ordinarily in suicide, in some accidents, and sometimes as an act of homicide. The point of trajectory, the horizontal distance and the impact point are closely related to the initial velocity, angle and height. This study examines the falling pattern in order to determine the mental status of the jumper as well as the manner of death. Initial velocity is found using horizontal movement and height. A serial study of athletes performing both the running jump (long jump) and standing jump (swimmer's start jump) via biomechanical methods is described. The initial velocity of the running jump and standing jump in normal athletics is 9.15 and 2.70 m/s with initial jumping angles of 21 and 38 deg, respectively. The maximal horizontal velocity of 9.15 m/s is closely related to maximal strength of initial velocity, angle of engaged force, and height. Theoretical estimation of the initial velocity between 2.70 and 9.15 m/s is correlative with the unique initial velocity and running jump to fall from a height that is closely related to the voluntary and attempted jump. Hence, the jumping victim with an initial velocity higher than 2.70 m/s implies suicide. These results indicate that horizontal distance and height are legitimate measures to use in speculating on the falling pattern and the manner of death. A unique case of suicide involving a run and jump with initial velocity greater than 2.70 m/s is illustrated.

Distribution of codeine, morphine, and 6-acetylmorphine in vitreous humor.

Two hundred and twenty-three vitreous humor specimens, which were obtained from a medical examiner's office, were found to be opiate positive (cutoff, 50 ng/mL) by fluorescence polarization immunoassay. All samples were analyzed for their free codeine, morphine, and 6-acetylmorphine contents by a gas chromatography-mass spectrometry protocol. 6-Acetylmorphine was found (cutoff, 10 ng/mL) in 41 specimens in the concentration range of 10-125 ng/mL. Twenty specimens had a free codeine-free morphine concentration ratio > or = 1. Eighty-five samples that were found to contain 50 ng/mL free morphine were further analyzed for their total codeine and total morphine contents. Total codeine-total morphine concentration ratios in 8 (of the 85 samples) were > or = 1, whereas this ratio in the others (only those with a codeine concentration high than 15 ng/mL were included) was significantly lower than 1. The codeine-morphine concentration ratio in vitreous humor appears to resemble that reported for blood and urine and can be used as the basis for differentiating between codeine- and morphine- (heroin-) induced fatalities.

Rupture of dissecting aneurysm in a China Airlines co-pilot.

A 46-year-old male co-pilot of China Airlines developed shortness of breath during landing on a flight from Tokyo to Taipei on May 17, 1994. He was found dead shortly after landing. He was well and had passed his semi-annual health examination with no history of cardiovascular disease or hereditary disease. A dissecting aneurysm of DeBakey type I and cardiac tamponade with 200 ml blood inside the pericardial cavity during autopsy was noted. The right and left coronary arteries showed atherosclerotic changes with the lumen narrowing down to 30% in the anterior descending branch. Focal myocardial infarction with a healing scar, atheroma and arteriosclerosis of the small arteries including the kidney were observed. Nonspecific changes of the chest X-Ray and EKG with hyperlipoproteinemia suggests that a more advanced technique is required to carefully examine the heart condition during regular physical checkups to prevent sudden illness that might contribute to mass disaster.

Functional properties of the nicotinic and glutamatergic receptors.

Several important physiological processes such as plasticity, memory, cell death, and rhythmic firing involve the N-methyl-D-aspartate (NMDA)-type of glutamatergic receptor. Nicotinic acetylcholine receptors (AChR), recently demonstrated in the central nervous system (CNS), are also of great interest. We have used several ligands to study the physiology and pharmacology of the agonist recognition sites of these receptors and kinetic properties of associated ion channels using whole-cell, cell-attached or outside-out variants of the patch-clamp technique. Enzymatically dissociated frog interosseal muscles were used to study peripheral AChRs, and tissue cultured or acutely dissociated hippocampal neurons and retinal ganglion cells (RGCs) for CNS receptors. For reproducible and fast solution changes when recording in the whole-cell configuration, we modified the "U"-shaped tube system to obtain different outputs from the same outflow port. We used fluorescent rhodamine-labeled latex microspheres to identify RGCs. Our studies provide important information regarding the molecular mechanisms of several clinically used agents. Additionally, similar actions of noncompetitive agents on the ion channels of the nicotinic ACh and NMDA receptors support the concept of a receptor ion channel superfamily.

Cellular responses to Pyrularia thionin are mediated by Ca2+ influx and phospholipase A2 activation and are inhibited by thionin tyrosine iodination.

Pyrularia thionin, isolated from nuts of Pyrularia pubera, is a strongly basic peptide of 47 amino acids. The amino acid sequence and configuration of its four disulfide bonds place this plant peptide, known to be hemolytic, cytotoxic, and neurotoxic, among the thionins. We report and compare several cellular responses mediated by Pyrularia thionin: hemolysis of human erythrocytes, activation of an endogenous phospholipase A2 in Swiss 3T3 cells, cytotoxicity toward HeLa and mouse B16 melanoma cells in culture, viability of rat hepatocytes and lymphocytes measured by trypan blue exclusion, and lethality in mice. Cellular responses related to ion movement include a toxin-mediated influx of Ca2+ into mouse P388 cells measured by Fura-2 fluorescence, depolarization of mouse P388 plasma membrane measured by fluorescence of bis(1,3-diethylthiobarbituric acid)trimethine oxonol (bisoxonol), and depolarization of frog (Rana pipiens) sartorius muscle determined by direct measurement of membrane potential. Graded iodination of Pyrularia thionin leads to a related loss of activity for hemolysis, phospholipase A2 activation, cytotoxicity, and lethality in mice. The mediated Ca2+ influx into and depolarization of P388 cells require Ca2+ in the external medium and are inhibited by 100 microM Ni2+. Depolarization of sartorius muscle by Pyrularia thionin also requires a functional Ca2+ channel, as shown by verapamil inhibition. This muscle depolarization also involves phospholipase A2 activation because dexamethasone and quinacrin, but not indomethacin, protect against depolarization. The IC50 values for viability of rat hepatocytes and splenic lymphocytes measured by trypan blue exclusion were 0.17 and 40 microM, respectively. The general response of cells to Pyrularia thionin involves a membrane alteration leading to depolarization and a channel-mediated influx of Ca2+. There is a related activation of phospholipase A2 that results in loss of membrane integrity, hemolysis in the case of erythrocytes, and eventually cell death. Iodination of Pyrularia thionin leads to a corresponding inhibition of all three cellular responses, which indicates an essential role for tyrosine in either maintenance of peptide structure or interaction of the peptide with cellular membranes.

The reversible cholinesterase inhibitor physostigmine has channel-blocking and agonist effects on the acetylcholine receptor-ion channel complex.

The actions of the carbamate cholinesterase inhibitors, physostigmine (Phy) and physostigmine methiodide (MetPhy), were studied on the acetylcholine receptor-ion channel complex (AChR) of skeletal muscles. Low concentrations of these agents produced cholinesterase inhibition which resulted in potentiation of nerve-elicited muscle twitches and an increased peak amplitude and prolongation of the decay time constant (tau EPC) of endplate currents (EPCs) elicited in frog (Rana pipiens) sartorius muscles. However, increasing concentrations of Phy depressed the peak amplitude and shortened the decay phase of the EPC with an apparent loss in the voltage dependence of tau EPC. At higher concentrations and depolarized potentials, EPC decays were double exponential. The effects of both Phy and MetPhy on the postsynaptic AChR complex were also evident in preparations pretreated with diisopropylfluorophosphate. Under these conditions, a linear relationship between the reciprocal of tau EPC and the concentration of these agents was observed. Single channel studies revealed that Phy (20-600 microM) shortened channel lifetime and decreased channel conductance at very high concentrations. In addition, Phy (0.5 microM) induced the appearance of channel openings with conductance similar to that of acetylcholine. High concentrations (greater than 50 microM) of this agent activated channel openings with decreased conductance. Similar results were obtained with MetPhy. Thus, the reversible cholinesterase inhibitors Phy and MetPhy altered the properties of the AChR by interacting as agonists capable of inducing desensitization and blockade.

The interaction of anticholinesterase agents with the acetylcholine receptor-ionic channel complex.

The actions of pyridostigmine (Pyr), a quaternary carbamate compound, and physostigmine ( Phy ), a tertiary carbamate, both known for their reversible inhibition of acetylcholinesterase (AChE), were studied on the electrically excitable membrane and acetylcholine (ACh) receptor of the frog cutaneous pectoris, sartorius, and interosseal muscles, as well as the chronically denervated soleus muscle of the rat and myoballs from neonatal rats. Both Pyr and Phy first potentiated, then depressed and finally blocked the indirectly evoked muscle twitch. Pyr and Phy had negligible effects upon either membrane potential or muscle action potential. But at the synaptic junction, they decreased the peak amplitude of the endplate current (EPC) in a voltage- and concentration-dependent manner. Pyridostigmine produced a marked prolongation of the decay time constants of both the EPC and the miniature endplate current ( MEPC ), while maintaining a single exponential decay, and Phy decreased peak amplitude, while having little effect on its voltage dependence. Physostigmine also decreased the decay time constant, suggesting a channel block, presumably in open state. Single channel recordings using patch clamp techniques disclosed that Pyr interacts with the ACh receptor as a weak agonist capable of inducing desensitization, alone, and when combined with ACh. Physostigmine interacts directly with the ACh-ionic channel complex, blocking it in open conformation.

The nature of the interactions of pyridostigmine with the nicotinic acetylcholine receptor-ionic channel complex. I. Agonist, desensitizing, and binding properties.

The actions of pyridostigmine (Pyr), an anticholinesterase agent, were studied on the acetylcholine (ACh) receptor-ion channel complex and on the electrically excitable membrane of the frog cutaneous pectoris and sartorius muscles and the chronically denervated soleus muscle of the rat. Pyr at concentrations of 0.2-0.4 mM potentiated the indirect evoked muscle twitch and at concentrations greater than or equal to 0.8 mM depressed the indirect twitch with an IC50 of about 2 mM. Twitch depression produced by Pyr was reversed slowly, and after a 60-min wash only 59% of the control muscle twitch had returned. Pyr did not affect either the membrane potential or the muscle action potential. Pyr had several effects at the neuromuscular junction of the frog and rat. It decreased the peak amplitude of the end-plate current (EPC) in a voltage- and concentration-dependent manner. In contrast to diisopropylfluorophosphate, which depresses the EPC amplitude and induces a double exponential decay of the EPC and miniature end-plate current (MEPC), Pyr produced a marked prolongation of the time constants of EPC and MEPC decay while maintaining a single exponential decay. The decrease caused by Pyr of indirect twitch tension, EPC amplitude, and ACh sensitivity indicates mechanisms which limit the number and/or properties of conducting channels. The drug decreased channel conductance and prolonged channel lifetime as revealed by Fourier analysis of ACh-induced end-plate current fluctuations. An altered form of the conducting species induced by Pyr appears to be responsible for either the apparent agonist-induced depolarization or its ability to increase the affinity of ACh for its recognition site. Pyr was also found to inhibit the binding of ACh and alpha-bungarotoxin to receptor-rich membrane from the electric organ of Torpedo nobiliana, and to have a higher affinity for the receptor than for the ion channel binding sites. These actions are distinct from acetylcholinesterase inhibition caused by the agent. Strong evidence suggests that the direct influences of the agent on neuromuscular transmission involve at least three distinct, although possibly interacting, mechanisms: (a) a weak agonist action, (b) the formation of desensitized receptor-complex intermediates, and (c) the alteration of the conductance properties of active channels.

Covalent attachment of diethylstilbestrol to glutamate dehydrogenase: implications for allosteric regulation.

An affinity labeling reagent for the estrogenic-binding site of bovine liver L-glutamate dehydrogenase (EC 1.4.1.3) was prepared by conversion of diethylstilbestrol to its alkylating analogue, bromoacetyldiethylstilbestrol. Under standard assay conditions, the analogue acted as a reversible allosteric ligand with regulatory activity much like that of diethylstilbestrol. However, incubation of the enzyme with the alkylating agent in the presence of DPNH resulted in a permanent decrease in glutamate (X form) and an increase in alanine (Y form) activities, and in covalent attachment of diethylstilbestrol in the ratio of 1 mol per subunit (of particle weight 52,000). The brominated analogue behaved as an affinity label that mimicked the allosteric effects of diethylstilbestrol. Diethylstilbestrol protection of the enzyme against alkylation by bromoacetylated sterol suggested competition for the same binding site, while ADP protection indicated a shift of protein equilibrium into the X form. The diethylstilbestrol-enzyme compound was desensitized (relative to the native enzyme) to allosteric reagents such as ADP and GTP. The results were consistent with conformational freezing of the modified protein molecule into the Y form.