A new method for diatom detection is described. It includes an ultrasonic irradiation procedure with the use of a tissue solubilizer. The method is easy to carry out and is less time-consuming than previous techniques.

Aged↗

PubMedDate not supplied

Sex identification of forensic specimens by polymerase chain reaction (PCR): two alternative methods.

Sex identification of forensic samples (bloodstains and decomposed tissue) by polymerase chain reaction (PCR) was investigated. Amplification of a segment of the amelogenin gene using a pair of primers revealed both Y- and X-specific bands at the same time. The gene has counterparts in both the X and Y chromosomes and a small deletion in the former made it possible to distinguish them. Analysis of the X-specific band is the most reliable method for sex identification. THe locus includes a single copy gene so a sample of 250 ng/tube of deoxyribonucleic acid (DNA) is required for identification. Amplification of part of the DYZ1 locus was attempted as an alternative method for analysis of infinitesimal amounts of sample. Even DNA from putrefied tissue could be analyzed by PCR because the locus consists of thousands of copies of repeating units pHY10.

Amelogenin↗

PubMedDate not supplied

1-Methyl-tetrahydro-beta-carboline-3-carboxylic acid is present in the rat brain and is not increased after acute ethanol injection with cyanamide treatment.

We conducted analyses of 1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid (1Me3C-THBC) by gas chromatography-mass spectrometry (negative chemical ionization mode) to investigate its presence and the in vivo condensation between tryptophan and AcH. 1Me3C-THBC was found in the cerebellum and the cerebrum of normal rat [117.0 +/- 41.7 and 46.5 +/- 13.9 pmol/g tissue (mean +/- SEM), respectively]. The concentrations of 1Me3C-THBC and tryptophan were higher in the cerebellum than those in the cerebrum. The level of 1Me3C-THBC in both regions remained unchanged following a single oral ethanol administration alone or with cyanamide pretreatment. These data suggest that acetaldehyde is an unlike precursor of 1Me3C-THBC as a result of ethanol ingestion. 1Me3C-THBC also existed in the rat chow (282.0 +/- 24.2 pmol/g), so that most of brain 1Me3C-THBC detected in the rat brain might have originated from dietary sources. However, the possibility of a biosynthesis from tryptophan and alpha-keto acid still remained, especially after long-term ethanol treatment.

Acetaldehyde↗

PubMedDate not supplied

Modulation of tryptophan hydroxylase activity in vitro by ethanol depends on biopterin cofactor concentration.

The mechanism of ethanol action at serotonergic neuronal systems in the brain was investigated by examining the effects of alcohols on the activity of tryptophan hydroxylase (TPH) in vitro using natural type of biopterin as cofactor. Alcohols inhibited the activity of TPH prepared from rat brain in a noncompetitive manner with respect to both the biopterin cofactor and the L-tryptophan substrate. The rank order of inhibitory potency of the tested alcohols was n-propanol > iso-propanol > ethanol > methanol. The kinetic study indicated that alcohols more potently affected the enzyme interaction with cofactor than substrate. Ethanol, at concentrations that can be reasonably attained in vivo (i.e., 25-100 mM) significantly decreased TPH activity in the presence of a physiological concentration of cofactor. However, the reduction was only approximately 5% of control activity, because Ki, values of ethanol for the enzyme were very high (800-1000 mM). From the present results, it was concluded that the direct inhibition of the synthetic enzyme itself by ethanol would contribute little to in vivo effects of ethanol on serotonergic neuronal systems.

1-Propanol↗

PubMedDate not supplied

Spontaneous rupture of mediastinal cystic teratoma into the pleural cavity: report of two cases and review of the literature.

The authors report on two female patients aged 12 and 14 years, who spontaneously developed a rupture of benign mediastinal cystic teratoma into the right pleural cavity. They presented with acute onset of severe chest pain and respiratory distress. The tumors were completely resected by thoracotomy. The serum and pleural fluid levels of carcinoembryonic antigens, CA-125 and CA19-9 were invariably elevated, then decreased to normal range after the surgical resection. Rapid diagnosis of this extremely rare complication is important because it may progress to a life-threatening condition.

Adolescent↗

PubMedDate not supplied

Determination of S-benzyl-N-acetyl-L-cysteine by gas chromatography/mass spectrometry as a new marker of toluene exposure.

We investigated by gas chromatography/mass spectrometry if S-benzyl-N-acetyl-L-cysteine (SBAC) is excreted into the urine of six printing workers and 20 sniffers after exposure to toluene. SBAC was extracted from 10 mL urine with chloroform and back extracted into 1M sodium bicarbonate. After acidfying, the sample was reextracted with ethyl acetate. The SBAC in urine was also measured by selected ion monitoring methods, using deuterium-labeled SBAC as an internal standard. An excellent linearity was obtained from 0.01 to 3.0 mg/L (r = 0.998). Urinary concentrations of SBAC were determined quantitatively in all samples from sniffers and printing workers (n = 26, 0.02-43.29 mg/L) but were not determined in the urine of persons not exposed to toluene (n = 40). The results of this experiment indicate that SBAC is excreted as a minor metabolite of toluene in human urine. The analysis of urinary SBAC is a useful tool in identifying toluene exposure.

Acetylcysteine↗