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PubMed2001

Binding, pharmacological and immunological profiles of the delta-selective opioid receptor antagonist HS 378.

HS 378 is a recently developed indolomorphinan with high selectivity and antagonist potency at the delta-opioid receptor. The present study was performed to characterize the opioid binding properties and pharmacological and immunological activity of HS 378 and to compare them with those of two well-known delta-opioid receptor antagonists, naltrindole (NTI) and naltriben (NTB). In vitro opioid receptor binding profiles were determined in rat brain homogenates. HS 378 showed 4.7- and 2.4-fold higher mu/delta selectivity compared to NTI and NTB, respectively. In the [35S]GTPgammaS functional assay carried out in cell lines expressing cloned human opioid receptors, HS 378 was found to be a pure delta-opioid receptor antagonist. In vitro, exposure of HS 378 resulted in an apparent dose-related suppression of concanavalin A induced rat T-lymphocyte proliferation with an IC50 value of 0.54 microM. NTI showed also immunosuppression with an IC50 value of 6.93 microM, whereas NTB had no effect. The IC50 of HS 378 was 13 times lower than that of NTI and 8 times higher than that of cyclosporin A. Taken together, our findings indicate that the small molecule HS 378 has properties that may be of therapeutic value in the setting of human inflammatory diseases.

Animals↗
PubMed2001

HS-599: a novel long acting opioid analgesic does not induce place-preference in rats.

1. When administered subcutaneously HS-599, a new didehydroderivative of buprenorphine (18,19-dehydrobuprenorphine), produced a long-lasting antinociceptive response in rats. Its potency exceeded twice that of buprenorphine. In the tail-flick test it acted as a full agonist but in the plantar test only as a partial agonist. Whereas the mu-opioid antagonists naloxone and naltrexone antagonized HS-599 antinociception the delta-opioid antagonist naltrindole and the kappa-opioid antagonist nor-binaltorphimine did not. 2. Unlike buprenorphine and morphine, HS-599 never induced conditioned place-preference in rats. 3. In radioligand binding assays, compared with buprenorphine HS-599 had 3 fold higher mu-opioid receptor affinity but lower delta- and kappa-opioid receptor affinity. 4. In isolated guinea-pig ileum preparations, HS-599 only partially inhibited the electrically-stimulated contraction, acting as a partial opioid agonist. When tested against the mu-opioid receptor agonist dermorphin, it behaved as a non-equilibrium antagonist. Conversely, in mouse vas deferens (rich in delta-opioid receptors) and rabbit vas deferens preparations (rich in kappa-opioid receptors) HS-599 acted as a pure equilibrium antagonist, shifting the log-concentration-response curves of the delta-opioid agonist deltorphin I and the kappa-opioid agonist U-69593 to the right. 5. In conclusion, HS-599 is a novel buprenorphine derivative with higher affinity, selectivity and potency than the parent compound, for mu-opioid receptors. It produces intense and long-lasting antinociception and does not induce place-preference in rats.

Analgesics, Opioid↗
PubMedDate not supplied

Macrophage-like cell line (HS-P) from a rat histiocytic sarcoma.

With future exploration of macrophage properties in mind, we established a novel cell line (HS-P) from a transplantable histiocytic sarcoma, derived originally from a tumour in an aged F344 rat. HS-P was subjected to 70 serial passages, in which the mean doubling time was 15.7 h. The cells, which were round, oval or polygonal in shape, were arranged in a compact sheet. They reacted to varying degrees for lysosomal enzymes (acid phosphatase and non-specific esterase) and with the following antibodies: ED1/ED2 (rat macrophage/histiocyte-specific), OX6 (rat MHC class II-specific), lysozyme antibody and alpha1-antichymotrypsin antibody. Electron microscopically, HS-P cells showed lysosomes and prominent cell projections. These findings indicated that the cultured cells were macrophage-like. Syngeneic rats inoculated subcutaneously or intraperitoneally with HS-P cells invariably developed sarcomatous tumours consisting of monomorphic mononuclear cells, which exhibited cytochemical properties similar to those of cultured HS-P cells. Bioassay and reverse transcription-polymerase chain reaction methods revealed that tumour necrosis factor-alpha increased on addition of lipopolysaccharide (LPS), indicating that HS-P cells remained LPS-responsive. HS-P cells may prove to be a useful tool for in-vitro studies of macrophage function.

Acid Phosphatase↗
PubMed2001

Effects of lipopolysaccharide on a macrophage-like cell line (HS-P) from a rat histiocytic sarcoma.

Lipopolysaccharide (LPS) is a major modulator of macrophage functions. To characterize a newly established rat histiocytic sarcoma-derived cell line (HS-P), immunophenotypic changes and cellular growth responses of HS-P cells exposed to LPS were investigated and compared with those of MT-9 cells isolated from a rat malignant fibrous histiocytoma. MT-9 cells have somewhat histiocytic features, because occasional cells react to rat macrophage-specific antibodies. Addition of LPS to cultured HS-P cells increased the numbers of cells immunopositive to ED1 (rat macrophage-specific antibody) and ED2 (rat histiocyte-specific antibody) and stimulated the phagocytosis of latex beads, whereas LPS-treated MT-9 cells did not show such immunophenotypic changes. LPS-treated HS-P cells showed enhanced immunolabelling of alpha-smooth muscle actin, suggesting a possible modulation of macrophages towards myofibroblastic cells. To evaluate cellular growth after the addition of LPS or fetal bovine serum, DNA synthesis was examined by measuring tritiated thymidine incorporation, and the mRNA expression of c- jun and c- myc (immediate early genes in the cell cycle) was examined by Northern blot analysis. In HS-P cells, the addition of serum greatly increased DNA synthesis and induced high expression of c- jun and c- myc; in contrast, LPS markedly depressed DNA synthesis and reduced the expression of c- jun and c- myc. HS-P cells were more sensitive than MT-9 cells to the growth-promoting effect of serum and the growth-inhibiting effect of LPS. The study demonstrated that HS-P cells are highly LPS-responsive, indicating that they would be useful for studies of macrophage functions.

Animals↗
PubMed1998

Cloning and expression analysis of a novel salicylate suppressible gene, Hs-CUL-3, a member of cullin/Cdc53 family.

By using a mRNA differential display technique to search for salicylate suppressible genes, we identified a cDNA in human foreskin fibroblasts, which by GenBankTM DNA data base search shows sequence homology to the recently reported cullin/Cdc53 (CUL) family genes, especially CUL-3. We have cloned the full-length human CUL-3 (Hs-CUL-3) cDNA. It encodes a 768-amino acid polypeptide and has a predicted molecular weight of 88,939. The amino acid sequence of Hs-CUL-3 shows 46% homology to that of its Caenorhabditis elegans ortholog, Ce-CUL-3, and 27 and 23% to that of Hs-CUL-1 and Hs-CUL-2, respectively. Northern blot analysis showed that phorbol 12-myristate 13-acetate increased the expression of Hs-CUL-3 mRNA in a concentration- and time-dependent manner, and this increase was inhibited by sodium salicylate. Hs-CUL-3 widely expressed in human tissues and its expression in cultured COLO205 colon cancer cells was increased when compared with that in normal colon cells. It is likely that Hs-CUL-3 is involved in cell proliferation control.

Amino Acid Sequence↗
PubMed2001

Molecular population genetic analysis of Campylobacter jejuni HS:19 associated with Guillain-Barré syndrome and gastroenteritis.

Infection with Campylobacter jejuni serotype HS:19 is associated with the development of Guillain-Barré syndrome (GBS). To determine whether a particular HS:19 clone is associated with GBS, multilocus enzyme electrophoresis (MLEE) was used to analyze a worldwide collection of isolates. There were 34 electropherotypes (ETs) in 3 phylogenetic clusters among 83 C. jejuni isolates. Cluster I contained all HS:19 strains, and a single ET (ET4) accounted for most HS:19 strains. HS:19 strains did not occur in any of the other clusters. ET4 contained isolates from different geographic locations, indicating global spread of this clone. Furthermore, ET4 contained isolates from patients with uncomplicated enteritis and GBS, as well as isolates from animal sources. The results of this study show that HS:19 strains comprise a clonal, although not monomorphic, population, which is distinct from non-HS:19 strains within C. jejuni. A unique clone associated with GBS was not identified by use of MLEE.

Campylobacter Infections↗
PubMed1995

Evaluation of a total hematology analysis system (Sysmex HS-430). Benefits for large laboratories by reducing manual work load and optimizing screening efficacy for pathologic samples.

In this study, the authors evaluated a closed tube total hematology analysis system, Sysmex HS-430 (HS), which consists of two automated hematology analyzers, Sysmex NE-8000, the reticulocyte analyzer, Sysmex R-3000, and a slide preparation unit integrated in an automated sample transport system (TOA Medical Electronics, Kobe, Japan). The suitability of the system was compared with a conventional hematology system (CS) consisting of two single standing Coulter STKS analyzers (Hialeah, FL), one automated reticulocyte counter Sysmex R-1000, and the manual blood smear preparation. Evaluation was performed following the concept suggested by the Austrian-German societies for Clinical Chemistry and Laboratory Medicine that includes the evaluation of personnel supply. Eight consecutive series with a total of 4,896 samples were analyzed on both systems. Evaluation revealed that the analysis time per series was 238 minutes on the HS-430 and 359 minutes on the CS. The mean analyzer down times because of technical reasons were 36 minutes on the HS and 32 minutes on the CS. The down time because of "nontechnical" reasons was 31 minutes on the HS-430, but 173 minutes on the CS, which was mainly because of discontinuous sample loading of analyzers of the CS. The average direct technical time effort for complete blood cell count (CBC) analyses, reticulocyte counts, and blood smear preparations per series was 23 minutes on the HS and 245 minutes on the CS. In summary, these data show that an automated system like the HS-430 saves 222 minutes of manual activities arising in a large routine hematology laboratory with a mean throughout of 612 samples per day. Furthermore, the system improves intralaboratory turnaround times, avoids human errors by automated sample identification, and guarantees more safety for laboratory staff by minimizing the contact with potential biohazards.

Blood Cell Count↗
PubMed1997

The atrial natriuretic peptide receptor antagonist HS 142-1 improves cardiovascular filling and mean arterial pressure in a hyperdynamic ovine model of sepsis.

OBJECTIVE: To test whether systemic vascular resistance and mean arterial pressure increase during the administration of the atrial natriuretic peptide antagonist, HS 142-1, in ovine experimental hyperdynamic sepsis. DESIGN: Prospective trial. SETTING: Research laboratory at a large university medical center. SUBJECTS: Chronically instrumented Merino breed ewes (n = 14). INTERVENTIONS: Continuous infusion of Pseudomonas aeruginosa (2.5 x 10(6) colony-forming units/min) for the experimental period of 48 hrs. One group (HS 142-1) received a continuous infusion of HS 142-1 (3 mg/kg/hr) from 40 to 48 hrs; the remaining sheep ("control") were given the vehicle sodium chloride 0.9%. MEASUREMENTS AND MAIN RESULTS: All sheep developed a hyperdynamic cardiovascular response by 40 hrs that was characterized by low values of systemic vascular resistance index (p < .05) and mean arterial pressure (p < .05), and an increased cardiac index (p < .05). HS 142-1 increased cardiac filling pressures (p < .05) without apparent effects on fluid balance, and was associated with a significantly (p < .05) higher mean arterial pressure than was found in the control group at 44 and 48 hrs. HS 142-1 did not change systemic vascular resistance index. At 44 and 48 hrs, cardiac index values were found to have significantly (p < .05) increased in the animals receiving HS 142-1, when these data were compared with cardiac output values at 40 hrs. CONCLUSION: HS 142-1 increases cardiac filling pressures and maintains mean arterial pressure in hyperdynamic sepsis without reversal of sepsis-induced vasodilation.

Animals↗
PubMedDate not supplied

Electron microscopic immunolocalization of a conserved sperm acrosomal antigen recognized by HS-63 monoclonal antibody.

HS-63 monoclonal antibody was shown to react with a sperm-specific acrosomal antigen from spermatozoa of a variety of mammalian species. Indirect immunofluorescence showed that HS-63 was associated with acrosome-intact sperm after sperm had been fixed with methanol. Electron microscopy (EM) was employed to determine the ultrastructural localization of this sperm antigen. When the immunogold labelled goat anti-mouse IgG was used as a probe, we demonstrated that HS-63 monoclonal antibody did not bind to the freshly prepared human spermatozoa. However, gold particles were observed in the intra-acrosomal region, when the spermatozoa had been pre-treated with 0.5% Triton X-100 prior to incubation with HS-63. We further observed that the immunogold did not stain the inner acrosome membrane when the spermatozoa became acrosome-reacted. A good correlation was obtained between the percentage of spermatozoa which did not react with HS-63 as determined by indirect immunofluorescence assay and that of acrosome-reacted spermatozoa as quantitated by electron microscopy. The results of this EM study were consistent with those obtained by indirect immunofluorescence assay and both indicated that HS-63 reacts only with the capacitated and acrosome-intact spermatozoa. Therefore, HS-63 monoclonal antibody is a useful probe for rapid evaluation of acrosomal status in human spermatozoa.

Acrosome↗
PubMed2005

Peripherally mediated antinociception of the mu-opioid receptor agonist 2-[(4,5alpha-epoxy-3-hydroxy-14beta-methoxy-17-methylmorphinan-6beta-yl)amino]acetic acid (HS-731) after subcutaneous and oral administration in rats with carrageenan-induced hindpaw inflammation.

Opioids induce analgesia by activating opioid receptors not only within the central nervous system but also on peripheral sensory neurons. This study investigated peripherally mediated antinociception produced by the mu-opioid receptor agonist 2-[(4,5alpha-epoxy-3-hydroxy-14beta-methoxy-17-methylmorphinan-6beta-yl)amino]acetic acid (HS-731) after s.c. and oral administration in rats with carrageenan-induced hindpaw inflammation. Antinociceptive effects after s.c. administration were assessed 3 h after intraplantar carrageenan injection and compared with those of centrally acting mu-opioid agonists 14-methoxymetopon and morphine. Opioid agonists caused dose-dependent increases in inflamed paw withdrawal latencies to mechanical and thermal stimulation. The time course of action was different, in that HS-731 (20 microg/kg s.c.) produced significant long-lasting effects up to 4 h after administration, whereas 14-methoxymetopon (20 microg/kg) and morphine (2 mg/kg) reached their peak of action at 10 to 30 min, and their effect declined rapidly thereafter. Subcutaneous administration of the peripherally selective opioid antagonist naloxone methiodide inhibited antinociception elicited by HS-731 (20 microg/kg s.c.), whereas it was ineffective against 14-methoxymetopon (20 microg/kg s.c.). Moreover, the antinociception produced by 100 microg/kg s.c. HS-731 was dose-dependently reversed by s.c. naloxone methiodide. This indicates that HS-731 preferentially activates peripheral opioid receptors, whereas 14-methoxymetopon mediates analgesia via central mechanisms. Orally administered HS-731 significantly reduced hyperalgesia in the inflamed paw induced by carrageenan, which was reversible by s.c. administered naloxone methiodide. These results show that systemic (s.c. and oral) treatment with the mu-opioid agonist HS-731 produces potent and long-lasting antinociception through peripheral mechanisms in rats with carrageenan-induced hindpaw inflammation.

Administration, Oral↗
PubMed1978

The ganglionic blocking properties of the cholinesterase reactivator, HS-6.

Following intravenous administration of the cholinesterase reactivator HS-6 (30 mg/kg), blood pressure fell (up to 50 mmHg) and maximal blood levels of HS-6 reached 242 microgram/ml. HS-6 attenuated the pressor response resulting from carotid occlusion and the depressor effect of vagal stimulation. Doses of HS-6 below those used to protect against soman in different animal species (10--30 mumol/kg) progressively blocked the ganglion-stimulating effects of nicotine and dimethylphenylpiperazinium but not the pressor effect following adrenaline, a pattern similar to that produced by hexamethonium but only 1/84 as potent. HS-6, like hexamethonium and mecamylamine, progressively blocked the contraction of the nictitating membrane of the cat resulting from preganglionic stimulation. The results indicate that HS-6 possesses ganglion-blocking properties at doses likely to be used in the protection against soman poisoning. The ganglion-blocking properties of the drug may be a factor in the beneficial effects of HS-6.

Animals↗
PubMed1983

Interaction of alpha 2-HS-glycoprotein with immobilized triazine dyes.

We studied the interaction of alpha 2-HS-glycoprotein with immobilized Cibacron blue F3-GA (Blue A) and Procion red HE-3B (Red A). When whole plasma was applied on the Blue A, alpha 2-HS-glycoprotein remained unbound, together with other plasma proteins. In contrast, when this fraction was applied on the Red A, alpha 2-HS-glycoprotein was shown to bind tightly and was eluted with a linear sodium chloride gradient between 0.5 and 0.8 M. This proved to be a useful two-step technique for the purification of alpha 2-HS-glycoprotein. Further characterization revealed that the protein appeared homogeneous by immunoelectrophoresis and SDS-polyacrylamide gel electrophoresis with yields greater than 30%. A small (less than 5%) but significant fraction of alpha 2-HS-glycoprotein with a same molecular weight as the native protein was consistently found in the wash of the Red A column, and may correspond to alpha 2-HS-glycoprotein bound to a yet unidentified ligand.

Blood Proteins↗
PubMed2005

Fucoidan induces apoptosis of human HS-sultan cells accompanied by activation of caspase-3 and down-regulation of ERK pathways.

Fucoidan, a sulfated polysaccharide in brown seaweed, was found to inhibit proliferation and induce apoptosis in human lymphoma HS-Sultan cell lines. Fucoidan-induced apoptosis was accompanied by the activation of caspase-3 and was partially prevented by pretreatment with a pan-caspase inhibitor, z-VAD-FMK. The mitochondrial potential in HS-Sultan cells was decreased 24 hr after treatment with fucoidan, indicating that fucoidan induced apoptosis through a mitochondrial pathway. When HS-Sultan was treated with 100 microg/mL fucoidan for 24 hr, phosphorylation of ERK and GSK markedly decreased. In contrast, phosphorylation of p38 and Akt was not altered by treatment with fucoidan. L-selectin and P-selectin are known to be receptors of fucoidan; however, as HS-Sultan does not express either of these selectins, it is unlikely that fucoidan induced apoptosis through them in HS-Sultan. The neutralizing antibody, Dreg56, against human L-selectin did not prevent the inhibitory effect of fucoidan on the proliferation of IM9 and MOLT4 cells, both of which express L-selectin; thus it is possible fucoidan induced apoptosis though different receptors. These results demonstrate that fucoidan has direct anti-cancer effects on human HS-Sultan cells through caspase and ERK pathways.

Antibodies↗
PubMed1979

Pharmacological actions of HS-6, an oxime, on the neuromuscular junction.

The effect of HS-6 [1-(2-hydroxyiminomethylpyridinium)-1-(3-carboxamidopyridinium)-dimethyl ether] on neuromuscular (NM) transmission was investigated using chick biventer cervicis (CBC), rat diaphragm (RD) and guinea pig ileum longitudinal muscle strip (GPLS) preparations. In the CBC preparation HS-6 did not cause a contraction, whereas it produced a dose-related contraction of the GPLS preparation. HS-6 produced a hemicholinium-like NM blockade in the CBC and RD preparations. This was supported by the fact that HS-6 inhibited choline uptake in erythrocytes. HS-6 inhibited the contractions of various nicotinic agonists in the CBC preparation and augmented the acetycholine contractions. The latter was due to AChE inhibition produced by HS-6.

Animals↗
PubMed1993

HS-142-1 inhibits testosterone production and guanosine-3':5'-cyclic monophosphate accumulation stimulated by atrial natriuretic peptide in isolated mouse Leydig cells.

In this report, we describe the effects of a recently described atrial natriuretic peptide (ANP) antagonist, HS-142-1, on the action of ANP on Percoll-purified mouse Leydig cells. Incubation of the Leydig cells with 10(-8) M ANP for 3 h resulted in a 16-fold stimulation of testosterone production over basal. Addition of HS-142-1 in a concentration range of 0.1 to 5 micrograms/ml resulted in a dose-dependent inhibition of ANP-induced testosterone production, a nearly complete inhibition being achieved with 5 micrograms/ml antagonist. Testosterone production by unstimulated cells or in cells stimulated with hCG was not affected by the antagonist. HS-142-1 was also able to inhibit the ANP-stimulated cyclic guanosine monophosphate (GMP) formation in the cells, in a dose-dependent manner. However, cyclic AMP level in cells stimulated with either forskolin or hCG remained unaffected by HS-142-1 even when added at a concentration of 5 micrograms/ml. Results obtained from 125I-ANP binding experiments showed that HS-142-1 is able to competitively inhibit the binding of the radioligand to its receptors on the Leydig cells. Thus evidence obtained in this study permit us to conclude that HS-142-1 is a potent and specific antagonist of ANP, has no toxic effect on the cells and is able to inhibit competitively the binding of ANP to its guanylate cyclase coupled receptors. Availability of such antagonists are likely to facilitate research on the physiology of ANP.

1-Methyl-3-isobutylxanthine↗
PubMed1992

HS-142-1, a novel nonpeptide atrial natriuretic peptide (ANP) antagonist, blocks ANP-induced renal responses through a specific interaction with guanylyl cyclase-linked receptors.

HS-142-1, a novel microbial product, blocked 125I-labeled rat atrial natriuretic peptide (rANP) (= ANF(99-126)) binding to bovine adrenocortical membranes, where guanylyl cyclase-containing receptors are predominantly expressed. However, HS-142-1 only slightly inhibited [125I]rANP binding to bovine lung membranes where only a small portion of binding sites are coupled to guanylyl cyclase. Further, HS-142-1 only recognized the 135 kDa ANP receptor, which is considered to be the guanylyl cyclase-containing receptor based on the results obtained in affinity cross-linking studies with bovine adrenocortical and lung membranes. Under identical conditions, Atriopeptin I selectively recognized guanylyl cyclase-free receptors both in binding and affinity cross-linking experiments. When injected intravenously (1 mg/kg) to anesthetized rats, HS-142-1 abolished ANP-induced diuresis and natriuresis. These results suggest that HS-142-1 works in vivo through a specific interaction with the ANP functional receptor, and that HS-142-1 will be a powerful tool for understanding the physiological roles of ANP in distinction from its pharmacological effects.

Adrenal Glands↗
PubMed2005

Further evidence of inflammation in chronic rheumatic valve disease (CRVD): high levels of advanced oxidation protein products (AOPP) and high sensitive C-reactive protein (hs-CRP).

Chronic rheumatic valve disease (CRVD) is a late sequel of Rheumatic Fever (RF) which appears in approximately 30% of RF patients, leading to valve injury. Advanced Oxidation Protein Products (AOPP) and high sensitive C-Reactive Protein (hs-CRP) plasma levels were measured in patients with CRVD in order to evaluate the presence of oxidative stress and systemic inflammation. A total of 90 patients (70 female, 20 male, mean age 46.01 +/- 11.72 years, range 24-69 years) with CRVD, who have or have not undergone valve replacement due to rheumatic etiology, and 46 healthy subjects (27 female, 19 male, mean age 41.89 +/- 9.02 years range 28-60 years) were studied. Levels of AOPP were measured by the determination of optical density (OD) at 340 nm under acidic conditions and hs-CRP by enhanced immunonephelometric assays. Significantly elevated levels of AOPP and hs-CRP were observed in CRVD patients when compared to the controls (AOPP 212.62 +/- 34.14 umol/l vs. 126.97 +/- 27.74 umol/l p < 0.00006 and for hs-CRP 5.40 +/- 1.98 mg/l vs. 2.66 +/- 1.36 mg/l p < 0.05). In addition, high levels of AOPP were associated to the presence of prosthetic valve and time after surgery (p < 0.0008 and p < 0.005, respectively). No correlation was observed between the levels of AOPP and hs-CRP with age, sex and degree of mitral valve stenosis. No correlation was found between AOPP and hs-CRP plasma values. These results suggest the involvement of oxidative stress and systemic inflammation in the pathogenesis of CRVD.

Adult↗
PubMed2000

Use of headspace solid-phase microextraction (HS-SPME) in hair analysis for organic compounds.

Headspace solid phase microextraction (HS-SPME) has advantages of high purity of the extract, avoidance of organic solvents and simple technical manipulation and can be used in combination with gas chromatography-mass spectrometry (GC-MS) in the hair analysis of a number of drugs. HS-SPME coupled with the hydrolysis of the hair matrix by 4% sodium hydroxide in the presence of excess sodium sulphate and of a suitable internal standard proved to be a convenient one-step method for the measurement of many lipophilic basic drugs such as nicotine, amphetamine derivatives, local anaesthetics, phencyclidine, ketamine, methadone, diphenhydramine, tramadol, tricyclic antidepressants and phenothiazines. Detection limits were between 0.05 and 1.0 ng/mg. From spiked 10-mg hair samples absolute recoveries between 0.04 and 5.7% were found. These recoveries decreased considerably if larger sample amounts were used, perhaps due to increased drug solubility in the aqueous phase or to elevated viscosity in the presence of dissolved hair proteins. Because of the phenolic hydroxyl group a change of pH after alkaline hair digestion (by adding excess orthophosphoric acid) was necessary for the detection of delta 9-tetrahydrocannabinol (delta 9-THC), cannabinol (CBN) and cannabidiol (CBD) by HS-SPME. Nevertheless, the detection limits were such that only CBN could be detected in hair of a consumer. Clomethiazole, a compound hydrolysed in alkali, was measured by HS-SPME after extraction with aqueous buffer. The detection limit was 0.5 ng/mg. Cocaine could not be detected by HS-SPME. The application of HS-SPME to hair samples from several forensic and clinical cases is described.

Antidepressive Agents, Tricyclic↗