OBJECTIVE: To investigate the feasibility of the new method of combining freeze grinding with ultrasonic technique for the pretreatment of the nail for toxicological and pharmaceutical analysis and to compare the advantages and disadvantages of this method with other traditional methods. METHODS: Five pretreatment methods were examined. Scanning electron microscope (SEM) was used to observe the microstructural changes of the nail. RESULTS: The microscopic structure of nail totally destroyed after alkali treatment. The hierarchy mode of the internal structure became obvious and tight after acid hydrolysis, which became indistinct after methanol infiltration. The structure of nail broke to pieces after ultrasonic technique. After freeze grinding combined ultrasonic technique, the particle structure kept original shape, and its size was one hundred times smaller than which after manual way. CONCLUSION The freeze grinding combined ultrasonic technique can improve the release efficiency, and ensure the stability of the toxicant or drug during the pretreatment process. It is appropriate for toxicological and pharmaceutical analysis in the nail.
Forensic Pathology ; Freeze Drying/methods* ; Humans ; Microscopy, Electron, Scanning ; Nails/chemistry* ; Particle Size ; Ultrasonics

This study was designed to assess the effect of implantation site and environment on early in vivo degradation behaviors of poly(L-lactide) (PLLA) and poly(L-lactide-co-glycolide) (PLGA) copolymer. The rods were implanted at two sites in each of 24 New Zealand White rabbits. The first site was within the suprapatellar bursa of the joint cavities (JC) and the second site was in the opposite condyles of femurs (CF). Three rabbits of each group underwent explantation of rods after 4, 8, 12, and 16 weeks. At each interval, measures were taken to evaluate the molecular weight, shear strength, weight loss and thermal properties of PLLA and PLGA. It was found that PLGA degraded slightly faster than PLLA. After 16 weeks, PLLA's initial inherent viscosity of 4.6 decreased to about 3.4 in both implantation sites while that of PLGA decreased from 4.6 to about 2.2. Both PLGA and PLLA showed enough shear strength retention in 16 weeks (> or = 53MPa) within 16 weeks. Autocatalysis mechanism was confirmed by the fact of accelerated weight loss of PLGA after 8 weeks and of PLLA after 12 weeks. The results revealed that PLGA could be a promising candidate material as a replacement of PLLA in internal fixation of bone fractures, and no significant difference of early in vivo degradation behaviors between PLLA and PLGA was observed in regard to different implantation sites in 16 weeks.
Absorbable Implants ; Animals ; Bone Nails ; Female ; Implants, Experimental ; Internal Fixators ; Lactic Acid ; chemistry ; metabolism ; Male ; Polyesters ; Polyglycolic Acid ; chemistry ; metabolism ; Polymers ; chemistry ; metabolism ; Rabbits

As a keratinized material, nail recently has attracting researchers' attention in the pharmaceuticals analysis. There are comparatively limited studies concerning nail's xenobiotic determination and its mechanism. This article reported the development of a sensitive, specific and reproducible LC-MS/MS method, which could be as a foundation of other studies on drug determination in nail. It can also be regarded as the first report on organic drug in mainland China. Sixteen nail samples from volunteers, who were ingested clozapine for more than nine months, are confirmed positive after being analyzed by the method. It is found that contents of clozapine in the patients' nails are above the nanogram level. Besides, a comparative study of clozapine concentration in nails and hair was made, with a result that there exists a correlation between the two materials in terms of clozapine concentration.
Adult ; Antipsychotic Agents ; pharmacokinetics ; China ; Chromatography, Liquid ; methods ; Clozapine ; pharmacokinetics ; Female ; Hair ; chemistry ; Humans ; Male ; Middle Aged ; Nails ; chemistry ; Psychotic Disorders ; metabolism ; Tandem Mass Spectrometry ; methods

OBJECTIVES: Nail has been a substitute DNA source for genotyping. To investigate the integrity and consistency of nail DNA amplification for biomarker study, nail clippings from 12 subjects were collected at monthly intervals. The possibility of longer amplification and existence of GAPDH RNA/protein, were also investigated with three nail samples. METHODS: Three primer sets were designed for quantitative amplification of nuclear and mitochondrial genes and analysis of their consistency. The mean threshold cycles in amplification of the target genes were compared to test the consistency of polymerase chain reaction (PCR) performance among individual factors including age groups, sex, family, the nail source, and by the size of the amplification segments. RESULTS: The amplification of the target genes from nail DNA showed similar integrity and consistency between the nail sources, and among the serial collections. However, nail DNA from those in their forties showed earlier threshold cycles in amplification than those in their teens or seventies. Mitochondrial DNA (mtDNA) showed better DNA integrity and consistency in amplification of all three targets than did nuclear DNA (nucDNA). Over 9 kb of mtDNA was successfully amplified, and nested quantitative PCR showed reliable copy numbers (%) between the two loci. Reverse transcription PCR for mRNA and immunoblotting for GAPDH protein successfully reflected their corresponding amounts. Regarding the existence of RNA and protein in nails, more effective extraction and detection methods need to be set up to validate the feasibility in biomarker study. CONCLUSIONS: Nail DNA might be a feasible intra-individual monitoring biomarker. Considering integrity and consistency in target amplification, mtDNA would be a better target for biomarker research than nucDNA.
Adult ; Age Factors ; Aged ; Biological Markers/analysis ; Child ; DNA/*analysis/isolation & purification ; DNA Primers ; DNA, Mitochondrial/analysis ; Feasibility Studies ; Female ; Gene Amplification ; Humans ; Male ; Middle Aged ; Nails/*chemistry ; Pilot Projects

In forensic toxicology analysis, various types of biological samples have their own special characteristics and scope of applications. In this article, the physiological structure of nails, methods for collecting and pre-processing samples, and for analyzing some poisons and drugs in the nails are reviewed with details. This paper introduces the influence factors of drug abuse of the nails. The prospects of its further applications are concluded based on the research results. Nails, as an unconventional bio-sample without general application, show great potential and advantages in forensic toxicology.
Alprazolam/analysis* ; Azabicyclo Compounds/analysis* ; Chromatography, High Pressure Liquid/methods* ; Cocaine/analysis* ; Diazepam/analysis* ; Eszopiclone ; Forensic Toxicology/methods* ; Gas Chromatography-Mass Spectrometry/methods* ; Hair/chemistry* ; Humans ; Illicit Drugs/analysis* ; Nails/physiology* ; Piperazines/analysis* ; Specimen Handling/methods* ; Substance Abuse Detection/methods*