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Biomedical subjects

N Kuroda

Publications and source records attributed to N Kuroda.

At least 91 records · Page 5Linked to original sources

Contribution of the portal flow on hepatic tissue perfusion increases in reduced hepatic vascular bed.

Background: A hepatic artery-portal vein reciprocal response and hepatic hemodynamics have well been investigated under normal condition, but not under pathologic condition with decreased vascular bed. This study was designed to determine the hemodynamic changes in the hepatic blood flow, tissue perfusion and interrelationship between portal venous flow (PVF) and hepatic arterial flow (HAF) after inflow interruption in the various size of hepatic vascular bed. Methods: Anesthetized dogs were used to measure PVF and HAF using a transit time flow meter and hepatic tissue flow (HTF) using a laser Doppler flow meter before and after portal venous (PVO) or hepatic arterial occlusion (HAO) under various range of portal triad occlusion (PTO). Results: The ratio of HAF/TLF (total liver flow) was 38+/-14% under the basal condition. This ratio did not change under the 30% PTO where there was a similar decrease in PVF and HAF, but reduced to 25+/-12% under the 70% PTO where there was more selective reduction in HAF than PVF. Although a reciprocal HAF increase was observed under any conditions after PVO, the TLF and HTF decreases after PVO were largest under the 70% PTO with the highest PVF/TLF ratio. On the other hand, there was no reciprocal PVF increase in any conditions after HAO, and the TLF and HTF decreases after HAO were minimal under the 70% PTO with the lowest HAF/TLF ratio. Conclusions: With decreasing hepatic vascular bed, dependency of the remnant hepatic hemodynamics and tissue perfusion on the portal blood flow increased. These findings suggest that an integrity of portal venous flow becomes crucial in the remnant hepatic tissue perfusion after extensive hepatic resection.

Journal Article↗

Vinculin: its possible use as a marker of normal collecting ducts and renal neoplasms with collecting duct system phenotype.

Vinculin is a cytoskeletal protein associated with membrane actin-filament-attachment sites of cell-cell and cell-matrix adherens-type junctions. In this article, we examine the expression of vinculin to elucidate its role in human renal neoplasms. We reviewed surgically resected specimens and selected available tissue from 79 renal tumors in 78 patients. There were 55 men and 23 women. Their mean age was 61 years and the mean size of the renal tumors was 6.1 cm. All renal tumors were examined by immunohistochemistry using a monoclonal antibody against vinculin. Overall, 17 (21.5%) renal tumor samples reacted with vinculin. The positive ratio in various types of renal tumors was as follows: conventional-type (clear cell), 0/54; papillary-type, 5/12; chromophobe-type, 5/5; sarcomatoid-type, 3/4; collecting duct carcinoma, 3/3; and oncocytoma, 1/1. The positive rate of conventional-type renal cell carcinomas (RCCs) is significantly different from that of other renal tumors (P < .01). Normal kidney, conventional, and papillary-type RCCs exhibited positive signals in Western blot analysis. These results suggest that vinculin may serve as a useful marker of renal neoplasms with collecting duct system phenotype such as chromophobe-type RCC.

Biomarkers, Tumor↗

Clinicopathologic analysis of stage II-III hepatocellular carcinoma showing early massive recurrence after liver resection.

BACKGROUND AND AIMS: Prognosis after hepatectomy for hepatocellular carcinoma (HCC) has been improved by progress in the evaluation of hepatic functional reserve, surgical techniques and perioperative management. However, even when curative resection is performed at a relatively early stage, a considerable number of patients develop early intrahepatic and/or extrahepatic recurrence postoperatively. This study analyzed the clinicopathologic features of HCC with early recurrence. METHODS: We reviewed records of 513 consecutive patients who had undergone liver resection for HCC. There were 48 deaths within a year after surgery from recurrence, including 21 patients with stage II or III HCC (group I). Clinicopathologic parameters of group I patients were compared with those of 188 patients (group II) who developed recurrence following resection of stage II or III HCC and died more than 1 year after surgery. RESULTS: On univariate analysis, age, tumor diameter (phi), alpha-fetoprotein (AFP):phi and protein induced by vitamin K absence or antagonist II (PIVKA-II):phi were significantly greater in group I than in group II. Macroscopic portal vein invasion, microscopic vascular invasion, intrahepatic metastasis, poor differentiation, pleomorphism, sarcomatous change, vascular lake, and angiographic condensed pooling were more frequently observed in group I than group II. Five independent determinants were selected by multivariate analysis: AFP:phi, histologic pleomorphism, sarcomatous change, vascular lake and angiographic condensed pooling. CONCLUSIONS: Highly malignant HCC with extremely poor prognosis exhibits peculiar clinicopathologic characteristics, particularly histologic immaturity, and can be predicted by preoperative indicators such as markedly elevated tumor marker concentrations and condensed pooling on angiography.

Aged↗

Anaplastic carcinoma of the pancreas with rhabdoid features.

The malignant rhabdoid tumor (MRT) is histologically characterized by the invasive proliferation of polygonal to ovoid cells with abundant eosinophilic cytoplasm and eccentric vesicular nuclei with a prominent nucleolus. MRT frequently occurs in the kidney, but may also arise in other organs. However, MRT should be strictly distinguished from carcinomas with rhabdoid features. A post-mortem examination of a 68-year-old woman found an anaplastic carcinoma of the pancreas with rhabdoid features displaying extensive invasion into the neighboring tissues. To the best of our knowledge, this is the first case of a pancreatic tumor with rhabdoid features. Pathologists should consider that carcinomas showing rhabdoid features may also appear in the pancreas. As pancreatic tumors with rhabdoid features have characteristic histopathological features and poor prognosis compared to other pancreatic tumors, careful histopathological differential diagnosis is important.

Aged↗

Adult-onset giant juxtaglomerular cell tumor of the kidney.

The juxtaglomerular cell tumor (JGCT) of the kidney is a rare neoplasm which commonly secretes renin. This tumor often occurs in teenagers. This paper documents the 14th adult-onset (over 30-years-old) case with a giant JGCT which measured 9.0 x 8.0 x 7.5 cm. Histologically, this tumor was composed of both vascular and tubular components. Immunohistochemically, the vascular component reacted with renin, cytokeratin 7, ulex europaeus agglutinin-1, vascular endothelial growth factor (VEGF) and Flk-1 (VEGF-R2), whereas the tubular component was positive for renin, epithelial membrane antigen (EMA), cytokeratin 7, alpha-1-antitrypsin, VEGF and Flk-1. This finding suggests that both vascular and tubular components of JGCT may promote neoplastic proliferation via an autocrine mechanism through the action of VEGF.

Female↗

Bronchial granular cell tumor with osteopontin and osteonectin expression: a case report.

The case of a 52-year-old Japanese man with bronchial granular cell tumors with osteopontin and osteonectin expression is reported here because there have been few investigations of their expression in benign tumors. He was admitted because of sudden hematemesis. A bronchoscopic examination revealed a lobulated polypoid tumor located in the left and right bronchi. Histologically, most tumor cells had abundant granular eosinophilic cytoplasm and were immunoreactive for S-100, neuron-specific enolase (NSE), CD68 and vimentin. Moreover, osteopontin-positive tumor cells were randomly distributed in the tumor tissue, but few stromal cells were positive. In contrast, osteonectin was mainly expressed in the peripheral tumor cells and was also distributed in the stromal cells. Blood vessels at the tumor border in which osteonectin-positive tumor cells were distributed, proliferated moderately. These results suggest that osteopontin and osteonectin may play a role in the progression of granular cell tumors and in the interaction between the tumor and host or angiogenesis around the tumor, respectively.

Biomarkers, Tumor↗

An immunohistochemical study of developing glomeruli in human fetal kidneys.

BACKGROUND: In the glomerulonephritis, mesenchymal cells frequently repeat the expression of fetal immunohistochemical phenotypes. However, in human glomerulogenesis the phenotypic alteration of mesangial and other types of glomerular cells has not been clearly defined. Our aim was to clarify the characteristics of fetal mesangial cells and glomerular capillary endothelial cells, as well as their changes during glomerulogenesis using immunohistochemistry. METHODS: We examined the renal tissues of 34 autopsied fetuses and neonates, 5 children, and 5 adults using immunohistochemistry and immunoelectron microscopy, using antibodies for cytoskeletons, contraction-associated proteins, and endothelial cell markers. RESULTS: In the V and S stages, there were no cells showing mesangial and endothelial features within the vesicles and the S-shaped bodies. In the S stage, small blood vessels, consisting of endothelial cells (CD31+, CD34+) and primitive perivascular mesenchymal cells (alpha-smooth muscle actin+, low molecular caldesmon+, vimentin+), were branched from developing interlobular arteries and appeared to extend to the lower clefts of the S-shaped bodies. In the C stage, the perivascular mesenchymal cells aggregated at the root of the immature glomeruli. In the M stage, they migrated toward the periphery of immature glomeruli and gradually lost their fetal immunohistochemical features. Similarly, with further maturation, the fetal glomerular capillary endothelial cells gradually lost the immunostaining for CD34, while the strong staining intensity of CD31 remained unchanged, just as that in the adult glomerular capillary endothelial cells. CONCLUSIONS: In human glomerulogenesis, we demonstrate that fetal mesangial and capillary endothelial cells change their immunohistochemical phenotypes with maturation. They gradually lose fetal immunohistochemical phenotypes. Already before birth, the mesangial cells in almost all glomeruli at the late M stage acquire the adult phenotype.

Adolescent↗

Differential expression of CD34 in normal colorectal tissue, peritumoral inflammatory tissue, and tumour stroma.

AIMS: To investigate the role of CD34 positive stromal cells, namely dendritic interstitial cells, in the desmoplastic stroma formation of malignant epithelial neoplasms the distribution of CD34 positive stromal cells was examined in human colorectal adenocarcinomas, peritumoral inflammatory tissue, and normal tissue. METHODS: Forty one surgically resected human colorectal adenocarcinomas and their corresponding peritumoral inflammatory and normal tissues were examined. To distinguish CD34 positive stromal cells from vascular endothelial cells, immunostaining for both CD34 and CD31 was performed. The distribution of myofibroblasts was also analysed immunohistochemically, and double staining with CD34 and alpha smooth muscle actin (ASMA) was performed. RESULTS: Most of the stromal cells in the normal colorectal submucosa, muscularis propria, subserosa, and perirectal tissue were positive for CD34. In contrast, the peritumoral inflammatory tissue and the tumour stroma had no CD34 positive stromal cells. The distribution of myofibroblasts was almost the same as in the aforementioned series. No stromal cells double positive for CD34 and ASMA were detected in the peritumoral inflammatory tissues. CONCLUSIONS: Most stromal fibroblasts are CD34 positive stromal cells (dendritic interstitial cells). In colorectal adenocarcinomas, a lack of CD34 expression in stromal cells is associated with desmoplastic reaction.

Adenocarcinoma↗

Limited balloon expansion through the struts of the Palmaz-Schatz and NIR stents compared with the Multi-Link stent.

After placing a stent in the main vessel of a bifurcation lesion, it is sometimes necessary to perform further balloon inflation in order to treat an ostial lesion in a side branch. The stent struts may prevent full balloon expansion at the ostium of a side branch, resulting in residual ostial stenosis. The degree of completeness of balloon inflation may vary significantly depending on the stent design and structure. A model of a bifurcation lesion with an angle of 45 degrees was created from acrylic resin. The diameters of the main vessel and the side branch were both 3.5 mm. Deployment of the Palmaz-Schatz stent (n=5), NIR stent (n=5) or Multi-Link stent (n=5) was performed in the main vessel with a 3.5-mm balloon catheter inflated to 12 atm. A 3.5-mm balloon catheter was then inflated to 12 atm through the stent struts of the main vessel and into the ostium of the side branch. The degree of completeness of balloon inflation (% balloon expansion) was calculated as (smallest diameter of balloon catheter/reference diameter of balloon catheter) x 100%. The minimal lumen diameter (MLD) and cross-sectional area (CSA) at the ostium of the side branch created with the stent struts were also measured. Limited balloon expansion through the struts was observed with the Palmaz-Schatz stent and the NIR stent, but almost full balloon expansion was observed with the Multi-Link stent (% balloon expansion: Palmaz-Schatz stent 80%, NIR stent 60%, Multi-Link stent 94%, p<0.01). The MLD and CSA of the dilated struts, representing the ostium of the side branch, of the Palmaz-Schatz stent (2.2+/-0.1 mm, 4.5+/-0.3 mm2) and the NIR stent (1.8+/-0.1 mm, 3.1+/-0.3 mm2) were significantly smaller compared with those of the Multi-Link stent (3.0+/-0.2 mm, 8.4+/-0.6 mm2) (p<0.01). The struts of the Palmaz-Schatz stent and the NIR stent deployed in the main vessel of a bifurcation prevent full expansion of a balloon catheter inflated at the side branch ostium. In contrast, almost full balloon expansion through the struts of the Multi-Link stent is achieved.

Catheterization↗

Achiral and chiral quantification of methamphetamine and amphetamine in human urine by semi-micro column high-performance liquid chromatography and fluorescence detection.

In this paper, miniaturized achiral and chiral high-performance liquid chromatographic procedures for the determination of methamphetamine and amphetamine in human urine are described. After a simple pretreatment of human urine (i.e., 10 microL of urine or diluted urine were acidified and dried-up under N2 at room temperature) and fluorescence derivatization with 4-(4,5-diphenyl-1H-imidazol-2-yl)-benzoyl chloride under mild conditions (pH 9.0, 10 min at room temperature), the derivatives were isocratically separated on a semi-micro ODS column with Tris-HCl buffer (0.1 M, pH 7.0): acetonitrile (45 + 55 v/v) at a flow rate of 0.2 mL/min or their enantiomers were separated on a semi-micro OD-RH column with sodium hexafluorophosphate (0.3 M aq.): acetonitrile (44 + 56 v/v) at a flow rate of 0.1 mL/min as the mobile phase. Wide-ranged calibration curves were obtained with detection limits for the achiral and chiral analyses in the atto and femtomol levels, respectively, per injected volume. Satisfactory within- and between-day reproducibility data were obtained with both the methods with the highest relative standard deviation being 9.6%. The methods were applied to the determination of methamphetamine and amphetamine in human urine samples and the concentrations determined by the two methods were well correlated (r = 0.994).

Amphetamine↗

Sensitive high-performance liquid chromatographic determination with fluorescence detection of phenol and chlorophenols with 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride as a labeling reagent.

A sensitive HPLC method for the determination of phenol and chlorophenols was developed. The fluorescence labeling reaction of phenols with 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride (DIB-Cl) was completed in 30 min at 60 degrees C. The separation of DIB-derivatives of five representative phenols, i.e., phenol, o-, p-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, was achieved within 35 min with an ODS column using isocratic elution. The detection limits of these DIB derivatives at a signal-to-noise ratio (SIN) of 3 were in the range of 0.024 to 0.08 microM (0.12-0.45 pmol/20 microl injection). Twelve kinds of DIB derivatives with phenols containing mono-, di-, tri-, tetra- and penta-chlorophenol were also well separated within 208 min by changing the elution conditions. The derivatives were stable for at least for 24 h when they were placed at room temperature in the dark. The proposed method was applied to the assay of human urine samples and free and total phenol were determined. The relative standard deviations (RSDs) of the proposed method for within and between-day assay were <7.0% and <14.2%, respectively. The average concentrations of free and total phenol found in urine (n=6) were 4.3+/-2.5 and 29.5+/-14.0 microM, respectively.

Benzoates↗

CD34 expression as a novel marker of transformed mesangial cells in biopsied glomerular diseases.

CD34 is a marker of haematopoietic progenitor cells, stromal precursors, vascular endothelial cells, and a variety of stromal tumour cells. This immunohistochemical study examined the CD34 expression of glomerular mesangial cells in normal and diseased glomeruli and compared it with the staining patterns of alpha-smooth muscle actin (ASMA), as a transformed mesangial cell marker, and CD31, as an endothelial cell marker. In addition, the CD34 and ASMA expression of mesangial cells in various glomerulonephritis and the relationship of the immunostaining intensity to the severity of IgA nephropathy were semiquantitatively evaluated. In normal glomeruli, all cell types were negative for CD34, but in glomeruli in mesangial proliferative glomerulonephritis, CD34 was expressed exclusively in mesangial cells, corresponding to ASMA expression. The dendritic and scattered staining pattern, the mesangial location of positive signals, and the enhanced expression were clearly different from CD31 expression in diseased glomeruli. In comparison with normal controls, the grade of immunostaining for CD34 (CD34 INDEX) in mesangial proliferative glomerular diseases was higher than that of ASMA (ASMA INDEX). With the severity of glomerulonephritis, the CD34 INDEX gradually increased. These studies indicate that CD34 is a useful marker of mesangial transformation and that immunohistochemical examination with the anti-CD34 antibody is useful for the diagnosis and stage determination of glomerular diseases.

Actins↗

Simple and rapid high-performance liquid chromatography analysis of propentofylline and its main metabolites in serum using a direct injection technique.

A rapid, simple and reliable high-performance liquid chromatography (HPLC) column-switching method with UV detection (270 nm) for the simultaneous determination of propentofylline and its metabolites in human and rat sera was developed. The method involves direct injection of serum onto an HPLC column, which contains a shielded hydrophobic stationary phase for the separation of analytes from proteins in serum, and then loading the analytes onto a short octadecylsilylated silica gel (ODS) column using a switching valve. Propentofylline and its three metabolites in serum were separated from the serum components within 30 min after the injection. The detection limits (S/N = 3) of analytes spiked in human and rat sera ranged from 0.08 to 0.57 nmol/mL, and the net volume of serum used was 20 microL. The relative standard deviations for within- and between-day variations using rat serum were less than 4.3 and 5.6%, respectively. The method was used to determine propentofylline and its main metabolites in rat serum after a single intravenous dose of propentofylline (5 mg/kg).

Animals↗

Enantiomer-specific high-performance liquid chromatography with fluorescence detection of methamphetamines in abusers' hair and urine.

Enantiomer-specific high-performance liquid chromatography with fluorescence detection using 4-(4,5-diphenyl-1H-imidazol-2-yl)-benzoyl chloride as a fluorescence labeling reagent was applied to determine methamphetamine and its metabolites in abusers' hair and urine. Hair samples were segmentally analyzed based on 1 cm long segments. In four hair samples, only the S(+)-enantiomers of methamphetamine and its N-demethylated metabolite, S(+)-amphetamine were detected. Satisfactory correlation (r = 0.901) between the results of high-performance liquid chromatography-fluorescence and those of gas chromatography-nitrogen phosphorous detection was obtained (n = 19). In an abuser's urine sample, the S(+)- and R(-)-enantiomers of methamphetamine, amphetamine and para-hydroxymethamphetamine were detected. The degree of N-demethylation of S(+)-methamphetamine into the corresponding metabolite of amphetamine was significantly higher than that of the R(-)-enantiomer.

Chromatography, Gas↗

Difference in security of stent jail between Palmaz-Schatz, NIR, and Multi-Link stents: the effect of balloon inflation through stent struts.

After placing a stent in the main vessel of a bifurcation lesion, it is often necessary to perform further balloon inflation or stent placement through the stent struts in order to treat a lesion of the secondary vessel or side branch. This balloon inflation with dilatation through the cells of the stent in the main vessel results in stent strut disfigurement. This disfigurement causes various degrees of stenosis within the main vessel secondary to stent strut deformity. The degree of strut deformity, and therefore stenosis, may vary significantly depending on stent design and structure. A model of a bifurcation lesion with an angle of 45 degrees was created from acrylic resin. The diameters of the main vessel and the secondary vessel were both 3.5 mm. Deployment of the Palmaz-Schatz stent (PS, n = 5), NIR stent (n = 5), or Multi-Link stent (n = 5) was performed in the main vessel with a 3.5-mm balloon catheter inflated to 6 atm. A second 3.5-mm balloon catheter was then inflated to 6 atm through the stent struts of the main vessel and into the ostium of the secondary vessel. The minimal lumen diameter (MLD) and cross-sectional area (CSA) at the ostium of the side branch and the stenosis within the main vessel were then measured, taking into account the stent deformity that occurred. Kissing balloon dilatation with two 3.5-mm balloon catheters was then performed and the stenosis secondary to stent deformity in the main vessel was remeasured. The MLD of the Multi-Link stent at the side-branch ostium was greater compared with those of the Palmaz-Schatz stent or the NIR stent (2.4 +/- 0.1, 1.6 +/- 0.1, 1.7 +/- 0.1 mm, P < 0.01) and CSA (4.9 +/- 0.5, 2.7 +/- 0.3, 2.5 +/- 0.3 mm(2), P < 0.01). Balloon inflation through the stent struts caused stent deformity that resulted in some degree of stenosis within the stent of the main vessel in all three stent types. Kissing balloon inflation reduced, but never eliminated, this stenosis. The percent stenosis in the main vessel secondary to stent deformity (PS 34% +/- 9%, NIR 25% +/- 8%, Multi-Link 34% +/- 7%, NS) and residual stenosis postkissing balloon inflation (PS 12% +/- 1%, NIR 10% +/- 3%, Multi-Link 14% +/- 3%, NS) were not significantly different among these three stents. At the side-branch ostium, the MLD and CSA were significantly greater for the Multi-Link stent compared with those of the Palmaz-Schatz or NIR stent. Balloon inflation through the stent struts caused stent deformity that resulted in stenosis within the stent in the main vessel. Kissing balloon inflation reduced this stenosis, but some residual stenosis always remained. The stenoses within the main vessel did not differ among the three stent types. Cathet. Cardiovasc. Intervent. 48:230-234, 1999.

Angioplasty, Balloon, Coronary↗

Dynamics of portal and peripheral endothelin-1 in hepatic resection and its implication.

BACKGROUND: The liver and portal circulation contribute to production and clearance of endothelin-1 (ET-1). This study was undertaken to investigate what variables relate to the dynamics of ET-1 in hepatic resection and its clinical implication. PATIENTS AND METHODS: On 20 patients with (n = 8) or without (n = 12) chronic liver disease who underwent hepatic resection, peripheral arterial and portal venous ET-1 were serially measured to determine a correlation with pre-, intra-, and postoperative variables. RESULTS: The preoperative factors with which the portal ET-1 showed a positive correlation were the indocyanine green retention rate at 15 min (ICG R15) and portal venous pressure. The ET-1 clearance, as calculated from the difference between the portal and the peripheral ET-1 concentrations, was also correlated with the ICG R15. The peripheral ET-1 elevated significantly in the patients with increasing intraoperative blood loss or hepatic inflow occlusion. An increase in the portal ET-1 was correlated with an elevation of portal venous pressure after hepatectomy. Postoperative increase in serum bilirubin was closely correlated with the peripheral ET-1 at closure. CONCLUSION: The peripheral and portal ET-1 are correlated with not only preoperative hepatic reserve and portal venous pressure but also invasiveness of hepatectomy and postoperative course.

Blood Loss, Surgical↗

Functional improvements in dried egg white through the Maillard reaction.

The effects of the Maillard reaction on the functional properties of dried egg white (DEW) were investigated. Maillard-reacted DEW (M-DEW) was prepared by storing sugar-preserved DEW (SP-DEW) at 55 degrees C and 35% relative humidity for 0-12 days. The M-DEW developed an excellent gelling property, and hydrogen sulfide production from heat-induced M-DEW gels decreased. Surface sulfhydryl (SH) group content of M-DEW increased while total SH group and alpha-helix contents decreased with increasing heating time in the dry state. Breaking strength, breaking strain, water-holding capacity, and hydrogen sulfide of heat-induced M-DEW gels significantly correlated with surface and total SH group contents in M-DEW. SDS-PAGE revealed that M-DEW proteins were polymerized in which covalent bonds were involved. The present study demonstrated that the Maillard reaction partially unfolds and polymerizes proteins of SP-DEW and, consequently, improved gelling property of SP-DEW under certain controlled conditions.

Cooking↗

HPLC with fluorescence detection of methamphetamine and amphetamine in segmentally analyzed human hair.

A sensitive high-performance liquid chromatographic method with fluorescence detection for determining methamphetamine and its major metabolite, amphetamine, in abusers' hair segments was developed. Methamphetamine and amphetamine in hair samples collected from addicts were extracted into acidified methanol, derivatized with 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride, separated isocratically on an ODS column using TRIS-HCl buffer (0.1 mol dm-3, pH 7.0)-methanol (30 + 70 v/v) as the mobile phase and the derivatives were detected fluorimetrically at 440 nm (lambda ex 330 nm). Calibration curves obtained by using control human hair spiked with standard solutions were linear (r > or = 0.999) up to at least 676.1 ng mg-1 for amphetamine and 746.1 ng mg-1 for methamphetamine. The detection limits at a signal-to-noise ratio of 3 were 51.4 and 74.6 pg mg-1 hair for amphetamine and methamphetamine, respectively. Using control hair spiked with standard solutions, the intra- and inter-day relative standard deviations (n = 5) were < or = 8.6% for both the target compounds. The method was successfully applied to the segmental analyses of methamphetamine abusers' hair samples.

Amphetamine↗