Hisanaga Kuroki

Cardiac lesions and their reversibility after long term administration of methamphetamine.

In order to clarify the effect of methamphetamine (MA) on myocardium, histological, immunohistochemical and electron microscopic changes in the myocardium of rats were examined following daily intraperitoneal administration of MA at a dose of 1 mg per kg body weight for 4, 8, and 12 weeks before sacrifice. Normal saline (NS) was similarly injected for the same period before sacrifice to constitute a control group. Light microscopic changes found in the myocardium of the MA-treated group included atrophy, hypertrophy, patchy cellular infiltration, eosinophilic degeneration and disarray, edema myolysis, fibrosis, and the appearance of vacuoles. Ultrastructurally, nuclei and normal mitochondria had various shapes and there were dilated T tubules and sarcoplasmic reticulum, the accumulation of glycogen granules and fat droplets. Intra- and extra-cellular edema and intramyocytic vacuoles were often found. Withdrawal of MA at the twelfth week in another group of rats evidenced gradual recovery of the myocardial changes, commencing at 3 weeks after withdrawal. Optimism is therefore generated about the possibility of the affected hearts in MA-abuse patients returning towards the normal state if they give up the drug.

Simultaneous detection of multiple STR loci on sex chromosomes for forensic testing of sex and identity

The forensic usefulness of X and Y chromosomal STR loci has recently been demonstrated. One quadruplex-PCR, using 2 X- and 2 Y-STRs (STRX1/HPRTB and DYS390/ DYS393), and 2 duplex-PCRs, each using an X- and a Y-STR (ARA/DYS390 and ARA/DYS393), and detection of PCR products by using an automated DNA sequencer are reported herein. This approach allows us to determine not only the sex of the donor of a sample, but also the X- and/or Y-STR genotypes of the sample. A male biological specimen yields 4 amplified products in quadruplex-PCR and 2 amplified fragments in duplex-PCRs, whereas a female biological specimen yields only 2 amplified fragments of X-STR in quadruplex-PCR and one fragment, also of X-STR, in duplex-PCRs. Our study thus provides useful information for many activities in forensic practice, such as identity testing, paternity testing, especially of deficiency cases, compilation of population data, and sex determination of a biological sample from a single PCR.

Retrospective review of Japanese sudden unexpected death in infancy: The importance of metabolic autopsy and expanded newborn screening

Sudden unexpected death in infancy is defined as sudden unexpected death occurring before 12 months of age. The common causes of sudden unexpected death in infancy are infection, cardiovascular anomaly, child abuse, and metabolic disorders. However, the many potential inherited metabolic disorders are difficult to diagnose at autopsy and may therefore be underdiagnosed as a cause of sudden unexpected death in infancy. In the present study we retrospectively reviewed 30 Japanese sudden unexpected death in infancy cases encountered between 2006 and 2009 at our institute. With postmortem blood acylcarnitine analysis and histological examination of the liver, we found two cases of long-chain fatty acid oxidation defects. Molecular analysis revealed that the one patient had a compound heterozygote for a novel mutation (p.L644S) and a disease-causing mutation (p.F383Y) in the carnitine palmitoyltransferase 2 gene. Furthermore, retrospective acylcarnitine analysis of the newborn screening card of this patient was consistent with carnitine palmitoyltransferase II deficiency. Metabolic autopsy and expanded newborn screening would be helpful for forensic scientists and pediatricians to diagnose fatty acid oxidation disorders and prevent sudden unexpected death in infancy.

Rapid and clear detection of ABO genotypes by simultaneous PCR-RFLP method.

We reported a new approach of ABO genotyping by a polymerase chain reaction and restriction fragment length polymorphism method. Instead of amplifying the loci containing the positions of nucleotides 258 and 700 of cDNA of the A transferase separately, we successfully amplified these 2 loci together in one reaction mixture using 2 sets of primers. The amplified DNA products were digested at the same time with restriction enzymes Kpn I and Alu I. The digested DNA products were then separated by electrophoresis on polyacrylamide gel. In addition, we evaluated the influence of various amplification parameters (concentration of template DNA, primers, Taq DNA polymerase, MgCl2, and number of cycles). In particular, high Mg2+ concentration (3.5 mM) made effective amplification of this locus without producing any unspecific band. By using that optimized condition for PCR, together with a simultaneous approach, our study proved to be time saving, more economic, and convenient in interpreting the results.

Direct cardiotoxic effects of cocaine and cocaethylene on isolated cardiomyocytes

We investigated the cardiotoxic effects of cocaine and cocaethylene on the Ca2+ flux responsible for excitation-contraction coupling in isolated ventricular rat myocytes. We simultaneously measured intracellular Ca2+ transients and cell length in isolated cardiac myocytes loaded with a fluorescent Ca2+ indicator, indo-1, during electrical field stimulation at 1 Hz. The cell length was estimated by video dimension analysis. We also measured the activities of Ca2+ ATPase and Ca2+ release channels of cardiac sarcoplasmic reticulum membrane vesicles. Both cocaine and cocaethylene produced significant decreases in both peak intracellular Ca2+ and the cell-contraction rate in a dose-dependent manner. The K0.5 for the reduction of peak intracellular Ca2+ was 157.5 microM for cocaine, but 90.0 microM for cocaethylene. Both cocaethylene and cocaine inhibited neither Ca2+ ATPase nor Ca2+ release channel activity. These results demonstrate that cocaethylene has a more potent direct negative inotropic action on cardiomyocytes, without preventing Ca2+ flux through the cardiac sarcoplasmic reticulum membrane.

Obesity and sudden unexpected deaths in Osaka, Japan

Obesity and cardiomegaly/hypertension may be strongly associated with sudden unexpected deaths (SUD) due to circulatory diseases. Six hundred and forty-nine SUD involving 402 postmortems, aged between 10 and 59 years in Osaka in 1997 were analyzed using the calculated body mass index (BMI) and the calculated degree of cardiac hypertrophy (DCH) by Hitosugi (Legal Med 1999;1:80). The percentage of individuals who died due to circulatory diseases was 54% in men and 64% in women, and at ages 50-59 years, 60% in men and 75% in women. It was 80% with DCH>/=20%, 84% for individuals with hypertension as a past illness and 80% with BMI>/=24. Thirty-four percent of all SUD have cardiomegaly more than 20%, 41% have BMI more than 24, and 17% have at least hypertension as a past illness.

Detection of D1S80 (pMCT118) locus polymorphism using semi-nested polymerase chain reaction in skeletal remains

We evaluated the usefulness of a semi-nested polymerase chain reaction (PCR) method for detecting D1S80 (pMCT118) locus polymorphisms of DNA extracted from old skeletal remains. The semi-nested PCR has been applied to the amplification of D1S80 nucleic acid sequences. For amplification of the locus D1S80, a pair of oligonucleotide primers have been used widely as described by Kasai et al. We have designed another set of primers for semi-nested PCR. This method resulted in D1S80-VNTR detection from low-titered DNA isolated from old skeletal remains. The first and second step PCR achieved amplification from as little as 10 ng and 10 pg of template DNA, respectively. Specificity and sensitivity of the amplification products was markedly improved by semi-nested PCR. In DNA extracted from biological samples, this method took about 5 hours to amplify the target DNA and 3 hours for electrophoretic separation. We demonstrated that this semi-nested PCR method was superior in sensitivity to conventional 1-step standard amplification for VNTR typing of the D1S80 locus.

A case of diffuse axonal injury in violent death

A 59-year-old man was carried to the hospital by three men. The deceased was unconscious at admission and his face was severely swollen with many subcutaneous hemorrhages and extensive edema. His death was confirmed 17 min after resuscitation. A judicial autopsy was performed the next day. Findings showed that the victims face and head were reddish and swollen, and that subscalp bleeding was ubiquitous, but no skull fracture, epi- and subdural hematoma or subarachnoidal bleeding was observed. The brain itself was severely edematous but no bleeding was found. Although small hemorrhages were seen in the limbs and back, there were no marked wounds except to the head. To determine the cause of death, we performed a microscopic histochemical examination. Conventional H.E. staining disclosed eosinophilic change, concentration of nuclei, edema, gliosis, and oozing at the corpus callosum. To identify further details of the cause of death, we used Bodian staining, Kluver-Barrera staining, anti-beta amyloid immunostaining, and anti-neurofilament immunostaining. We found sinusoidal swelling of axons and waving axons, which are typical findings of Diffuse Axonal Injury (DAI), but no positive staining of beta amyloid. Focal lesions of the corpus callosum and of the dorsolateral quadrant of the rostral brain stem, and diffuse damage to axons are considered to constitute the DAI triad. We therefore diagnosed the cause of death as DAI. Our experience shows that it is important to use several staining methods for diagnosis of a variety of neuronal degenerative disorders. Several days later, we were informed by the police that several men had hit and kicked the victim in an attempt to lynch him. To compare with this case, we also report two other cases in which DAI was observed.

Detection of Sequence Variants in Hypervariable Segments of Mitochondrial DNA in the Asian Population

The analysis of highly polymorphic regions of mitochondrial DNA is one of the most commonly used methods for personal identification. The recent advances of fluorescent detection in automated DNA sequencing (Smith et al. 1986) has made it possible a rapid analysis of sequence variants without using isotopic labeling.

Amplification and detection of the VNTR locus D4S95 in a Japanese population

The D4S95-VNTR locus was amplified and the polymorphism analysed in a population sample of 169 randomly selected Japanese individuals. A total of 14 alleles containing 850–1360 base pairs were distinguished by agarose gel electrophoresis. The distribution of alleles was symmetrical with respect to one peak at 1030 bp. The mean exclusion chance and discrimination power were calculated as 0.604 and 0.876 respectively.