Sensitive determination of four general anaesthetics in human whole blood by capillary gas chromatography with cryogenic oven trapping

Four general anaesthetics, sevoflurane, isoflurane, enflurane and halothane, in human whole blood, have been found measurable with very high sensitivity by capillary gas chromatography-flame ionization detection (GC-FID) with cryogenic oven trapping upon injection of headspace (HS) vapor sample. To a 7-ml vial, containing 0.48 ml of distilled water and 20 microl of internal standard solution (5 microg), a 0.5-ml of whole blood sample spiked with or without anaesthetics, was added, and the mixture was heated at 55 degrees C for 15 min. A measure of 10 ml HS vapor was injected into the GC in the splitless mode at -40 degrees C oven temperature, which was programmed up to 250 degrees C. All four peaks were clearly separated; no impurity peaks were found among their peaks. Their extraction efficiencies were about 10%. The calibration curves showed good linearity in the range of 0.5-20 microg/ml; their detection limits were 10-100 ng/ml, which are almost comparable to those by previous reports. The coefficients of intra-day and day-to-day variations were 6.5-9.8 and 7.3-17.2%, respectively. Isoflurane or enflurane was also measured from whole blood samples in which three volunteers inhaled each compound.

Development of lysosomal storage in mice with targeted disruption of the beta-galactosidase gene: a model of human G(M1)-gangliosidosis

A deficiency of lysosomal acid beta-galactosidase leads to G(M1)-gangliosidosis in humans, which progressively and profoundly affects the brain and other organs mainly in the early infantile period. We report the pathology of mice with targeted disruption of the beta-galactosidase gene. In the central nervous system, vacuolated neurons appeared in the spinal cord 3 days after birth. The vacuolation extended to neurons in the brainstem, cerebral cortex, hippocampus and thalamus and ballooning neurons became prominent with age. The vacuolation also appeared in Purkinje cells without a marked ballooning change. Reactive astrogliosis in the entire brain was marked at the terminal stage of the disease. Immunohistochemical study using anti-ganglioside G(M1) and G(A1) antibodies revealed extensive accumulation of G(M1) and G(A1) in the cerebral neurons. In the liver, however, accumulation of G(M1) was localized in the cytoplasm of hepatocytes, whereas that of G(A1) was localized in foamy macrophages and Kupffer cells. There were no significant abnormalities in the bone, bone marrow, or cornea at any stage. Although there are some phenotypic and biochemical differences between this knockout mouse and human GM1 gangliosidosis, the mouse will be a useful model for therapeutic trials for the human disease.

Identification of the critical spinal arteries with F wave-polysynaptic response complex monitoring: an experimental study

PURPOSE

The main cause of paraplegia after surgery for descending thoracic aortic aneurysms and thoracoabdominal aortic aneurysms is spinal cord ischemia caused by ligation of the critical spinal arteries that are associated with the great radicular artery (GRA). In this experimental study, we attempted to identify the critical spinal arteries with F wave-polysynaptic response complex (FPC) monitoring. The FPC, which we are using as a monitor of spinal cord ischemia, is myogenic potentials evoked by the tibial nerve stimulation through the anterior horn cells.

METHOD

In 18 rabbits, infrarenal lumbar arteries were clamped until there was an FPC amplitude reduction (FPCAR) of at least 60%. The rabbits were classified according to the number of arteries clamped to produce the FPCAR (group A, 1 artery; group B, 2 arteries; group C, 3 arteries). Selective angiography of each lumbar artery was performed in all rabbits.

RESULTS

An FPCAR was observed in all 18 rabbits. In all nine rabbits in group A, the FPCAR was caused by the clamping of one particular lumbar artery. The GRA was shown by means of selective angiography to originate directly from this lumbar artery. In the nine rabbits in groups B and C, 11 FPCARs were observed. Of these, nine FPCARs in nine rabbits were caused by the clamping of lumbar arteries that included the vessel from which the GRA originated.

CONCLUSION

Temporary clamping of lumbar arteries with FPC monitoring can be used as a means of detecting the critical spinal arteries from which the GRA originates.

Free vascularized toe joint transfer to the hand. A technique for simultaneous reconstruction of the soft tissue

Twelve patients underwent reconstruction of injured finger joints using our technique of a vascularized transfer of the second toe proximal interphalangeal joint. The age of the patients at operation ranged from 7 to 47 years and the postoperative follow-up was 9 to 48 months. All the joint transfers survived and united with resolution of the preoperative joint pain, deformity and instability. The average range of motion of the reconstructed joints was 59 degrees in the proximal interphalangeal and 54 degrees in the metacarpophalangeal joints. No patient complained of pain or functional deficits in the donor foot.

Sensitive determination of pethidine in body fluids by surface ionization organic mass spectrometry

We have presented a simple and sensitive method for determining pethidine, a narcotic analgesic drug in body fluids by gas chromatography (GC)/surface ionization organic mass spectrometry (SIOMS). Good linearity was obtained in the range of 0.625-25 ng/ml of whole blood and urine by mass chromatography, and in the range of 0.05-2 ng/ml of whole blood by selected ion monitoring (SIM). Pethidine and diphenylpyraline (internal standard) were extracted from body fluids with Bond Elut Certify cartridges; their recoveries were above 95%. The detection limits (signal-to-noise ratio=3) were estimated to be 0.2 ng/ml of whole blood or urine by mass chromatography, 0.02 ng/ml of whole blood by SIM.

Implantation of octacalcium phosphate nucleates isolated bone formation in rat skull defects

OBJECTIVE

Our previous radiographic examinations have indicated that the synthetic octacalcium phosphate (OCP) may provide the core for nucleating multiple osteogenic sites in the experimentally created cranial defect.

DESIGN

The present study was designed to confirm the possibility that the implanted OCP causes the osteoinduction as well as the osteoconduction in the rat cranial defect.

MATERIALS AND METHODS

Standardized defects were created in male Wistar rat calvaria, and the OCP granules were implanted into the defect. The sham operated rats were processed in the same way except that nothing was implanted. The rats were fixed at 4 weeks after implantation of OCP or the sham operation. We examined bone formed on the implanted OCP, analyzing serial sections histologically combined with immunohistochemistry for the bone specific protein, osteocalcin.

RESULTS

In the defects treated with OCP, the radiopacity was scattered throughout the defect besides being observed along the defect margin of the parietal bone. Examination of the serial sections showed that some of new bones on the implanted OCP were formed away from the defect margin of the parietal bone with regard to both histological identification and specific molecular marker.

CONCLUSIONS

The present study suggested that the implanted OCP can serve as a core for initiating bone formation and cause the osteoinduction as well as the osteoconduction in the defect.

Endovascular trapping of giant serpentine aneurysms by using Guglielmi detachable coils: successful reduction of mass effect. Report of two cases

Giant serpentine aneurysms (GSAs) are defined as partially thrombosed giant aneurysms with persistent serpentine vascular channels. Surgical management of these rare lesions is difficult because of their large size, complex structure, and unique hemodynamics. The authors report two cases of patients harboring GSAs with mass effect, which were managed effectively with endovascular treatment. The first patient was a 48-year-old man who presented with left homonymous hemianopsia caused by a GSA involving the terminal portion of the right internal carotid artery. The second patient, a 10-year-old boy, presented with tetraparesis from compression of the cervicomedullary junction by a GSA of the right vertebral artery. In each case, after confirming collateral flow by temporarily occluding the proximal artery, the aneurysm was trapped by placement of Guglielmi detachable coils at the sites at which the serpentine channels entered and exited the aneurysm. The midportion of each channel was isolated completely without packing, to maximize resorption of the devascularized mass. Mass effect and clinical symptoms rapidly improved in both cases, with no associated morbidity. We recommend endovascular trapping as a safe and effective therapeutic option for GSAs.

Embolization of arteriovenous malformations prior to radiosurgery

SUMMARY

Embolization prior to radiosurgery is useful to reduce the AVM nidus for adequate planning for radiosurgery. In 37 cases we encountered, patients with the least radiosurgical effects had diffuse type nidus, where the feeders embolized with absorbable embolic materials had the possibility of recanalization. The main purpose of embolization is to prevent bleeding while the radiosurgical effects are being fully obtained. Thus, nidus embolization and the occlusion of fistulous feeders, meningeal feeders and intranidal aneurysms using permanent embolic materials are essential, since effective and successful embolization can increase the occlusion rate and shorten the period until complete occlusion following radiosurgery.

Effectiveness and pitfall of embolization of cerebral arteriovenous malformations

We studied the course ofperisurgical complications of 66 AVMs and discussed the approapriate precautions. Of 66 patients with AVMs, 14 underwent postembolization surgical removal, and 43 underwent radiosurgery. Four patients were cured with total occlusion of their AVM by embolization alone. 48 patients achieved a more than 70% occlusion of the nidus. We observed 12 complications including 3 permanent and 9 temporary. Four complications occurred immediately after the embolization due to overembolization or thromboembolism, and 7 were observed several hours later which might have been caused by retrograde thrombosis or a chemical reaction to the glue. While presurgical embolization deepseated feeders must be embolized along with fistulous or high-flow feeders, 4 cases of 2nd embolization following radiosurgery showed that meningeal feeders developed or recanalized in cases embolized with absorbable particles. Thus, preradiosurgically, fistulous and meningeal feeders should be treated, and the nidus must be packed with embolic materials with no risk of recanalization. Successful nidus packing performed in 10 AVMs yielded a further nidus reduction before radiosurgery. The intranidal aneurysms which pose a high risk of rebleeding were also embolized. In order to avoid complications in the embolization of AVM, the angioarchitecture, hemodynamics and the relationship to brain function should be well recognized by preoperative functional imaging and superselective angiograms, and adequate embolic materials should be properly injected. As an embolization strategy, the priority of the target feeders should depend on the treatment to follow, and aggressive embolization of risky feeders or causing abrupt hemodynamic change should be avoided.

A new diquat derivative appropriate for colourimetric measurements of biological materials in the presence of paraquat

A new colourimetric method is described for the quantification of diquat using a yellow-coloured derivative produced by heating diquat in alkaline solution at 80 degrees C. The absorption maximum of the yellow derivative is 420 nm and the molar absorption coefficient is 2.76 x 10(4) (0.15 in 1 microgram diquat/ml with 1 cm light path). The absorption at 420 nm shows a linear concentration dependence in the range 0.1-10 micrograms/ml and fading of the colour is about 5% after 1 h. Under the same conditions, paraquat does not produce any coloured products. The concentration of diquat in the solution containing both diquat and paraquat can be determined by the absorption of diquat derivative at 420 nm without interference from paraquat. By adding sodium dithionite to the solution the concentration of paraquat can be determined by the absorption of paraquat radicals at 600 nm without interference from diquat, because the yellow derivative does not react with dithionite. This yellow diquat derivative can be extracted completely with cyclohexanol by saturating the solution with Na2SO4. The absorption maximum in cyclohexanol shifts to 440 nm with the same molar absorbance and the same half-band width as in water. Fading of the colour is less than 5% after 24 h in cyclohexanol. Perchloric acid (3%) and trichloroacetic acid (4.5%) which are often used for deproteinization of tissue homogenates, do not inhibit production of the coloured derivative at pH 13.5 or extraction of the derivative with cyclohexanol. This method is suitable for a quick determination of small amounts of diquat in tissues, since the extraction with cyclohexanol not only concentrates the derivative rapidly but also quite efficiently eliminates the coloured substances in tissue homogenates. The detection limit of diquat is 0.02 microgram/ml for blood and 0.05 microgram/g for liver when 1 ml or 1 g is used for analysis. In three human cases of fatal intoxication, both paraquat and diquat were quantified using 50 microliters of serum. In non-toxic dosing of diquat to rats for 14 days, the diquat level was highest in the spleen followed by the kidneys.

Profenofos metabolites in human poisoning

Profenofos and its metabolites were determined in a case of fatal poisoning. Little profenofos and large amounts of metabolites were detected by gas chromatography/flame photometric detection in the acid extracts of blood and urine after methylation with diazomethane. Four major metabolites containing phosphorus were identified with the synthesized metabolites, namely, despropylated profenofos, desethylated profenofos and des-S-propylated profenofos, respectively. 4-Bromo-2-chlorophenol (BCP), an aryl moiety of profenofos, was also determined in blood and urine with high performance liquid chromatograph (HPLC) as free or conjugated metabolites.

Lack of effect of the abnormal fatty acid metabolism in NC/Nga mice on their atopic dermatitis

Although clinical evidence has suggested that dysregulated fatty acid metabolism is associated with atopic disorders, the molecular basis for such a correlation remains to be demonstrated. In the present study, we analyzed the fatty acid composition in peripheral blood cells of NC/Nga mice, a model for atopic dermatitis (AD). We found that arachidonic acid significantly accumulated in mice with the AD manifestation. In addition, the leucotriene B4-releasing ability upon calcium ionophore A23187 stimulation was potentiated in blood cells. An arachidonic acid accumulation was not apparent in the non-atopic BALB/c strain, but was still observed in healthy NC/Nga mice fed under specific pathogen-free conditions. These results indicate that a disturbed fatty acid metabolism in NC/Nga mice was not a trigger factor for their dermatitis development.

Sensitive determination of n-hexane and cyclohexane in human body fluids by capillary gas chromatography with cryogenic oven trapping

A sensitive method was developed for determination of n-hexane and cyclohexane in human body fluids by headspace capillary gas chromatography (GC) with cryogenic oven trapping. Whole blood and urine samples containing n-hexane and cyclohexane were heated in a 7.5 mL vial at 70 degrees C for 15 min, and 5 mL of the headspace vapor was drawn into a glass syringe. All vapor was introduced through an injection port of a GC instrument in the splitless mode into an Rtx-Volatiles middle-bore capillary column at an oven temperature of -40 degrees C for trapping volatile compounds. The oven temperature was programmed to 180 degrees C for GC with flame ionization detection. These conditions gave sharp peaks for both n-hexane and cyclohexane, a good separation of each peak, and low background impurities for whole blood and urine. The extraction efficiencies of n-hexane and cyclohexane were 13.2-30.3% for whole blood and 12.7-20.7% for urine. The coefficients of within-day variation in terms of extraction efficiency of both compounds were 5.0-9.5% for whole blood and 3.8-10.8% for urine; those of day-to-day variation for the compounds were not greater than 16.6%. The regression equations for n-hexane and cyclohexane showed good linearity in the range of 5-500 ng/0.5 mL for whole blood and urine. The detection limits (signal-to-noise ratio = 3) for both compounds were 1.2 and 0.5 ng/0.5 mL for whole blood and urine, respectively. The data on n-hexane or cyclohexane in rat blood after inhalation of each compound are also presented.

Myxoid leiomyosarcoma of the uterus

A 70-year-old, menopausal Japanese woman with large uterine tumor underwent total hysterectomy. Microscopic examination revealed a myxoid leiomyosarcoma with 5 to 6 mitoses/10 high power field (HPF). Immunohistochemically, the tumor cells reacted with desmin, suggesting that they are derived from uterine smooth muscle cells. The patient was treated with the combination chemotherapy consisting of cisplatin, adriamycin and cyclophosphamide, and she has been free from disease for 70 months after the operation.

[From medicolegal toxicology to forensic toxicology]

The importance of forensic toxicology has been increasing until now, because of the increasing numbers of toxic substances and poisoning incidents. In Japan, a special translational word "houi-chudoku-gaku" has been used for the forensic toxicology especially in the field of legal medicine. The Japanese word, however, does not seem appropriate for translation of forensic toxicology, because it covers medicine, pharmacy and police sciences interdisciplinary. In 1980, Emeritus Prof. Hidetoshi Yoshimura created an appropriate word "hochudoku-gaku" for translation of forensic toxicology. In 1982, Prof. Yoshimura and his friends established the Japanese Association of Forensic Toxicology, consisting of people from legal medicine, pharmacy and police institutes. This Association enabled lively discussions among different fields and greatly contributed to advances of forensic toxicology in Japan. We started studies of forensic toxicology using gas chromatography (GC)/mass spectrometry (MS) in 1979. Until now, we delt with solid-phase extraction (1987-1994), surface ionization GC (1989-1997), negative ion chemical ionization MS (1981-now), solid-phase microextraction (1994-now), cryogenic oven trapping GC (1997-now), surface ionization organic MS (1998-now) and high-performance liquid chromatography/tandem MS (1998-now). In this review, the author presents some details of solid-phase microextraction, negative ion chemical ionization MS, cryogenic oven trapping GC and surface ionization organic MS. Unprecedented poisoning terrorism by use of sarin took place in Matsumoto and Tokyo in 1994 and 1995, respectively. On July 25, 1998, a curry poisoning incident using arsenious acid occurred in Wakayama, resulting in the death of 4 people and injury of 63 people. Since then, more than 30 imitative poisoning cases have been reported by mass communication within 1 year. In spite of the above continuing poisoning cases, almost no effective measures have been taken by the administration of our country and local governments. Many serious problems concerning poisoning and drug abuse are accumulating in Japan. In this review, the problems are also made manifest, and some proposals are presented to solve the problems.

[Prognostic factors of hepatocellular carcinoma: analysis by the proportional hazard model]

Five hundred fifty patients hospitalized to our hospital during 1990 to 1999 were studied. Subjects consisted of 413 males and 102 females and mean age was 62.1 years. Association with HBV infection, HCV infection and both infection was 11.1%, 78.4% and 2.5% respectively. According to the criteria based in Liver Cancer Study of Japan, 5 year survival rate in clinical stage I, II, III was 42.3%, 38.8% and 17.5%. Tumor morphology was nodular type in 78.9%, massive type in 9.1% and diffuse type in 10.5% of cases. Portal tumor thrombus and distal metastasis were observed in 19.9% and 6.3% of all cases. The 1-, 3- and 5-year survival rate in patients received any therapy was 80.8%, 44.6% and 28.7%, respectively. Analysis by the proportional hazard model showed that HBV infection, advanced clinical stage, multiple tumors, a tumor diameter in excess of 5 cm and AFP positivity were shown as significant factors on poor prognosis.

A curious autopsy case of accidental carbon monoxide poisoning in a motor vehicle

A 26-year-old man was found dead in his car. All doors and windows were locked inside. The ignition key was in the "on" position; but the engine was not running and the fuel tank was empty. His post-mortem lividity was cherry-pink, and marked congestion was observed in the lungs and brain macroscopically. Massive intracardiac blood containing a small amount of cruor was found in the heart. In histological examination of the heart, partial disarrangement or necrosis was found in the myocardium. The liver cells showed derangement and degenerative changes, with focal lymphocyte infiltration in the portal regions, although they were not severe. The chemical tests showed that the blood concentration of carboxyhemoglobin was 46.6%. Stimulants were also detected from his blood and urine; the concentrations of methamphetamine and amphetamine were 3.25 and 0.84 microg/ml, respectively, for his cardiac blood. Therefore, it seemed reasonable to judge that the cause of his death was carbon monoxide poisoning; the cardiomyopathy and the presence of stimulants in blood might facilitate his death. Upon careful investigation of his car, it was disclosed that exhaust gas, leaked from small holes of the exhaust pipe due to rust-through, invaded the interior through four holes on the floor of the car during parking with the engine being on for the purpose of air-conditioning of the interior. It is very common to commit suicide by introducing exhaust gas into an interior of a closed motor car, but the present accidental case of carbon monoxide poisoning in a car seems rare and worthwhile reporting.

Separation methods for amino group-possessing pesticides in biological samples

The separation methods for pesticides include liquid-liquid extraction, solid-phase extraction and solid-phase microextraction, gas chromatography (GC), GC-mass spectrometry (MS), GC-MS-MS, high-performance liquid chromatography (LC), LC-MS and LC-MS-MS. This review deals with each technique commonly used for extraction, chromatographic separation and detection of amino group possessing pesticides, such as diazines, triazines, carbamates, dinitroanilines and chloroacetanilides in biological samples. The methods presented for analysis of the pesticides in complicated biological matrices seem to be easily applicable to surface or groundwater in environmental chemistry.

Situations of poisoning and analytical toxicology in Japan

Unprecedented poisoning terrorism by use of sarin took place in Japan in 1994 and 1995. On July 25, 1998, a curry poisoning incident in Wakayama occurred resulting in the death of four people and injury of 63 people. Since then, more than 30 imitative poisoning cases have been reported by mass communication within 1 year. In this brief review, we present some details of a series of poisoning cases and measures taken by the Japanese Government and non-government groups. In addition some research projects on analytical toxicology being conducted in our laboratories are also introduced; gas chromatography (GC) with cryogenic oven trapping for volatile organic compounds, and GC/surface ionization organic mass spectrometry for tertiary amino compounds are described especially as new techniques for biological samples.

Analyses of butyrophenones and their analogues in whole blood by high-performance liquid chromatography-electrospray tandem mass spectrometry

Five butyrophenones and two analogues contained in human whole blood have been analyzed by high-performance liquid chromatography (HPLC)-electrospray (ES)-tandem mass spectrometry (MS). All compounds gave the base peaks due to [M+1]+ by HPLC-ES-single MS. The product ions formed from each quasi-molecular ion by HPLC-ES-tandem MS showed the base peaks at m/z 165 for four compounds. The mass chromatography of HPLC-ES-tandem MS showed much higher sensitivity than that of HPLC-ES-single MS for all drugs spiked to whole blood. Therefore, regression equations, detection limits, recovery rates and precision were studied for haloperidol, bromperidol and fluoropipamide spiked to human whole blood by means of mass chromatography of HPLC-ES-tandem MS. The three compounds showed good linearity in the range of 0.2-0.8 ng/ml with a detection limit of about 0.1 ng/ml. Recoveries of the three compounds spiked to whole blood (0.2 and 0.8 ng added to 1 ml whole blood) were 23.6-81.2%; the coefficients of intra- and inter-day variations were 8.4-10.4 and 14.5-17.5%, respectively. The three compounds in whole blood could be actually determined 3 and 6 h after oral administration of 1 mg each of haloperidol and bromperidol, and 10 mg of floropipamide in a volunteer.