Exploratory aspirin resistance trial in healthy Japanese volunteers (J-ART) using platelet aggregation as a measure of thrombogenicity.

Aspirin prevents the production of thromboxane A2 (TXA2) by irreversibly inhibiting platelet cyclooxygenase, exhibiting antiplatelet actions. This agent has been reported to prevent relapse in patients with ischemic heart disease or cerebral infarction via this action mechanism. However, there are individual differences in this action, and aspirin is not effective in some patients, which is referred to as 'aspirin resistance'. In this study, we analyzed laboratory aspirin resistance by platelet aggregation in 110 healthy adult Japanese males using 24 single-nucleotide polymorphisms (SNPs) of nine genes involved in platelet aggregation/hemorrhage. Among SNPs involved in platelet aggregation, aspirin was less effective for 924T homozygote of a TXA2 receptor, 924T>C, and 1018C homozygote of a platelet membrane glycoprotein GPIbalpha, 1018C>T, suggesting that 924T and 1018C alleles are involved in aspirin resistance.

Off-pump coronary artery bypass in a patient with the antiphospholipid syndrome.

Patients with antiphospholipid syndrome (APS) are prone to excessive postoperative morbidity and mortality after cardiovascular surgery because of its thromboembolic derangements. We present a case of coronary artery bypass grafting (CABG) in a patient with primary APS. He suffered from repetitive coronary occlusion after percutaneous transluminal coronary angioplasty (PTCA). Since his lupus anticoagulant level was found to be 217 s (normal, <50 s), he was diagnosed as the primary APS. He received steroid pulsation therapy with 1000 mg of prednisolone, double-filtration plasmapheresis (DFPP) and 50 mg of cyclophosphamide to attenuate the antibody activity. Four months after the last PTCA, he experienced chest pain and approximately 90% of stenosis in the left anterior descending (LAD) lesion was apparent, although the titer for the lupus anticoagulant was reduced to the normal range. He had drug allergy to ticlopidine hydrochloride and aspirin. Taken together, his disease was found to be resistant to these medical treatments, and surgical treatment was considered. Since cardiopulmonary bypass is known to exaggerate its coagulatory and fibrinolytic complications, off-pump CABG (OPCAB) was feasible in this case. The left internal thoracic artery (ITA) was anastomosed to the LAD using the off-pump technique. The procedure was successful, and the postoperative course for 3 years has been satisfactory without any cardiovascular complaints.

Histopathological and immunohistological analyses in IgA deficient lymphoplasia (aly/aly) mouse.

The aly/aly mouse has a severe immunodeficiency, because it lacks peripheral lymph nodes as well as IgA and IgG immunoglobulin synthesis. In the present study, we performed histopathological and immunohistological examinations to clarify histological disorders of various immune organs in these mice. Carbon CH40 injections into the apex of the tongue confirmed the absence of submandibular lymph nodes in aly/aly mice. The thymus had a poorly constructed cortex and medulla, and the number of lymphoid follicles was clearly decreased in the spleen. No IgG- or IgA- producing cells were found in any immune organs, including the mucosal immune sites, though several IgM -producing cells were identified. Other characteristic findings included perivascular lymphocytes accumulation in the salivary glands, lungs, liver and pancreas, which caused tissues damage. These results demonstrated that the various lymphoid tissues disorders and organ-specific lymphocyte infiltration cause immuno-deficiency in the aly/aly mouse.

[Acute angle-closure glaucoma following surgery for oral cancer].

A 60-year-old woman who had undergone surgery of oral cancer under general anesthesia developed an attack of acute angle-closure glaucoma the next morning. Her intraocular pressure decreased immediately by adequate treatments including surgical procedures (laser iridotomy and trabeculectomy), and her symptom improved. It is considered that this event was induced by several factors such as atropine given before and during general anesthesia, perioperative hypertension and anatomical abnormalities. However the definite cause of this event is unclear. We conclude that it is difficult to predict a glaucoma attack following surgery under general anesthesia, but this complication is an important ophthalmologic emergency. Immediate diagnosis and appropriate treatment should be done to prevent the grave prognosis.

A newly developed collagen/silicone bilayer membrane as a mucosal substitute: a preliminary report.

A new bilayer membrane proved effective as a mucosal substitute. The membrane is composed of an outer layer of silicone and an inner layer of dehydrothermally cross linked composites of fibrillar and denatured collagen sponge. The membrane was placed on oral mucosal defects of five patients after operations for cancer. Ten to 14 days after application the outer silicone sheet was removed, leaving only the inner collagen sponge layer into which cellular tufts of fibroblasts and capillaries had infiltrated. The infiltrated collagen matrix became a new connective tissue that epithelialised rapidly by migration of peripheral epithelium 4-5 weeks after application. In all cases the postoperative course was unremarkable and the repair was effective.

Rapid determination of a new angiotensin-converting enzyme inhibitor, imidapril, and its active metabolite in human plasma by negative-ion desorption chemical ionization-tandem mass spectrometry (MS/MS).

A very rapid and highly sensitive method using desorption chemical ionization (DCI)-tandem mass spectrometry (MS/MS) with selected reaction monitoring is reported for the simultaneous determination of imidapril and its active metabolite (M1) in human plasma. Imidapril and M1 in plasma were extracted by a C18 solid phase extraction cartridge after deproteinization, and derivatized with pentafluorobenzyl bromide. One microliter of prepared sample was applied to the DCI filament and analyzed by DCI/MS/MS within a few minutes. The limits of determination of imidapril and M1 were 0.2 and 0.5 ng/ml in human plasma, respectively. The features of this method make it appropriate for use in pharmacokinetic studies with human plasma after oral administration of imidapril.

[Clinical studies of ofloxacin 300 mg once a day administration in chronic respiratory tract infections].

Forty patients with chronic respiratory infections were randomly assigned to 2 groups to compare the effect of once daily administration of 300 mg each and 3 times daily administration of 600 mg each of ofloxacin (OFLX). Twenty patients were administered with 300 mg OFLX a day and 18 cases received 600 mg. The number of underlying diseases in the 300 mg group was greater than that in the 600 mg group. The ratios of general amelioration of clinical symptoms were 80.0% in the 300 mg group and 88.9% in the 600 mg group. For bacteriological effects, the eradication rate was 80.0% in the 300 mg group and it was 84.6% in the 600 mg. The incidence of side effects in the 300 mg group was 0% and that of the 600 mg group was 5.6% (1 patient) but the symptom was mild. The incidence of abnormal laboratory test results was 15.0% in the 300 mg group and it was 11.2% in the 600 mg group, but all of these abnormalities were slight and transient. The safety rates in the 300 mg and the 600 mg groups were 95.0% and 94.4%, respectively. Efficacy rates in the 300 mg and the 600 mg groups were 80.0% and 88.9%, respectively. There was no statistically significant difference in all the results between the 2 treatment groups, and the both treatments were highly effective. From the above results, we consider that once daily administration of 300 mg is a useful therapy in respiratory tract infections.

Determination of three metabolites of a new angiotensin-converting enzyme inhibitor, imidapril, in plasma and urine by gas chromatography-mass spectrometry using multiple ion detection.

A specific and sensitive gas chromatographic-mass spectrometric method for the determination of three metabolites of the angiotensin-converting enzyme inhibitor, imidapril, in plasma and urine was developed. The metabolites were isolated from plasma and urine using a Bond Elut C18 solid-phase extraction cartridge. The isolated metabolites were converted to sensitive derivatives by pentafluorobenzyl bromide and heptafluoro-n-butyric acid anhydride. Following derivatization, the sample solutions were analysed by wide-bore column gas chromatography-mass spectrometry with multiple ion detection. The detection limits of the three metabolites were each 1 ng/ml in plasma and 5 ng/ml in urine. Analysis of the spiked plasma and urine samples demonstrated the good accuracy and precision of the method. This method was very useful for use in pharmacokinetic and bioavailability studies of the three metabolites of imidapril in humans.

Synthesis of dibenzoylmethane derivatives and inhibition of mutagenicity in Salmonella typhimurium.

Twenty dibenzoylmethanes with methyl, methoxy, bromo, chloro, or fluoro substitution on either one or both benzene rings were synthesized and assayed for inhibition of the mutagenicity of 2-nitrofluorene in S. typhimurium TA98. 2,2-Dimethoxy, 3,3-dimethoxy and 3,3,4,4-tetramethoxydibenzoylmethane was as active as dibenzoylmethane. None of the halogen-substituted dibenzoylmethanes were active. These results demonstrate that dibenzoylmethanes can inhibit the mutagenicity of 2-nitrofluorene, and that modifications made on the benzene rings of dibenzoylmethane cannot enhance the antimutagenicity of this parent compound.

Assay of nicergoline and three metabolites in human plasma and urine by high-performance liquid chromatography-atmospheric pressure ionization mass spectrometry.

A method for the simultaneous determination of nicergoline and three of its metabolites in human plasma and urine has been developed using high-performance liquid chromatography-atmospheric pressure ionization mass spectrometry. Nicergoline and its metabolites were extracted from the plasma and urine samples with chloroform and separated on a reversed-phase ODS column. The eluents were led to the atmospheric pressure ionization interface and then analysed in the selected-ion monitoring mode. The detection limits of nicergoline and three of its metabolites were ca. 2 ng/ml in plasma and ca. 10 ng/ml in urine, at a signal-to-noise ratio of 4.

Analytical studies on the chiral separation and simultaneous determination of pantothenic acid and hopantenic acid enantiomers in rat plasma by gas chromatography-mass fragmentography.

The chiral separation and simultaneous determination of D- and L-pantothenic acids and D- and L-hopantenic acids in rat plasma using gas chromatography-mass fragmentography are described. The method is based on deproteinization by ion-exchange resin, extraction with ethyl acetate under acidic conditions, and derivatization to form several interesting compounds. After methyl esterification for carboxylic acid of D- and L-pantothenic acids, D- and L-hopantenic acids could be derivatized to trifluoroacetate, cyclic sulphite, and cyclic n-butylboronate for hydroxy groups. D- and L-forms of these derivatives were completely separated by mass fragmentographic technique with quasi-molecular ions. Calcium salt of D-5-[(2,4-dihydroxy-3,3-dimethyl-1-oxobutyl)amino]pentanoic acid was used as an internal standard for the determination of DL-pantothenic acids and DL-hopantenic acids. The detection limits of DL-pantothenic acids and DL-hopantenic acids in this method were 5 and 12 ng, respectively. This method could be applied to the study of plasma levels of D-, L-pantothenic acids and D-, L-hopantenic acids in rat.

Simultaneous determination of pantothenic acid and hopantenic acid in biological samples and natural products by gas chromatography-mass fragmentography.

A method for the simultaneous determination of pantothenic acid and hopantenic acid in plasma samples was developed using gas chromatography-mass spectrometry with multiple ion detection. Plasma samples were directly purified without deproteinization on an ion-exchange resin, and the eluate was extracted with ethyl acetate under acidic conditions. The organic layer was evaporated to dryness under a stream of nitrogen, and the residue was dissolved in an internal standard solution. Pantothenic and hopantenic acids were converted into their trimethylsilyl derivatives by treating with bis(trimethylsilyl)trifluoroacetamide. Aliquots of this solution were injected into the gas chromatograph-mass spectrometer, which was equipped with a wide-bore fused-silica column (DB-17) and analysed by the multiple ion detection method. The detection limits for pantothenic acid and hopantenic acid in plasma were 1 ng/ml each at a signal-to-noise ratio of 5. This method was applied to a study of the assay of pantothenic acid and hopantenic acid in biological samples and natural products.

Lectin cytochemistry of the dark granules in the type 1 cells of Syrian hamster circumvallate taste buds.

Lectin-gold complexes in the dark granules (DGs) and the dense substance (DS) of vallate taste buds were localized. Both the DGs and the DS were labelled with wheat-germ agglutinin, Ulex europeus agglutinin-I and peanut agglutinin. Their common reaction to these lectins suggested that the DGs contain carbohydrate components similar to those of the DS. The results provide cytochemical evidence that the DS in the taste pit represents, at least in part, the content of the DGs in the type 1 cells.