Itaru Furuta

A case of malignant transformation in thoracic vertebral hemangioma following repetitive irradiation and extraction

We report a rare case of thoracic vertebral hemangioma which developed into angiosarcoma during the course of repetitive operations and irradiation. A 44 year old female was operated on for hemangioma of the first thoracic vertebra. The diagnosis of hemangioma was confirmed histo‐pathologically with the specimen from the first operation. The tumor developed multiple lesions later in the clinical course after the first operation, these lesions were removed in four consecutive operations and each histologlcai diagnosis was that of hemangioma. Throughout the period of these operations, the patient was treated wtih steroid, and with radiotherapy simultaneously. The patient underwent the fifth operation for the recurrence of the tumor on 26 March 1990, and the histopathological diagnosis was not hemangioma but hemangiosarcoma which was considered a malignant transformation. The tumor cells immunohistochemically revealed positive staining with UEA‐I, Factor‐VIII, as the tumor immunohistochemically showed a vascular endothe‐lioid nature.

Rapid serum vancomycin assay by high-performance liquid chromatography using a semipermeable surface packing material column

A new isocratic high-performance liquid chromatographic (HPLC) assay has been developed for vancomycin that uses direct injection of microquantities of serum into a separation column filled with octyl-C(8) silica support that has a semipermeable surface. A mixture of disodium hydrogen phosphate buffer (pH 7.0) and acetonitrile is used as the mobile phase, and vancomycin is directly detected at 240 nm. The minimum limit of detection was 0.5 microg/ml at a signal-to-noise ratio of 3:1. Linearity was established from 0 to 100 microg/ml. The coefficient of variation for within-run reproducibility was 1.1-2.7% for a concentration range of 2.9-52.5 microg/ml; for day-to-day reproducibility it was 4.0% and 3.1% for a concentration range of 5.8-26.4 microg/ml, and the recovery rate was 94-105%. There was no interference from 41 antibiotics or other drugs currently in use. The correlation coefficient between the fluorescence polarization immunoassay (x) and this method (y) was 0.995 with a linear equation, y = 1.06x - 0.924. This method is simple, rapid, and provides an economical quantification of serum vancomycin.

Determination of vancomycin in human serum by micellar electrokinetic capillary chromatography with direct sample injection

BACKGROUND Vancomycin (VCM) has a bacteriostatic effect on gram-positive bacteria such as the methicillin-resistant Staphylococcus aureus. METHODS A new assay for measuring vancomycin concentration by micellar electrokinetic capillary chromatography using direct serum injection was developed. A borate buffer (pH 10.0) containing 100 mmol/l sodium dodecyl sulfate was used as an electrophoresis buffer, and the detection was at 210 nm. The migration time of vancomycin was approximately 7 min. RESULTS The linearity was from 0 to 100 microg/ml, with the limit of detection of 1.0 microg/ml (S/N=3). The within-run CV was 3.99-5.53%, and the recovery rate was 91-103% for a concentration range of 6.5-45.5 microg/ml. The between-day CV was 6.76% at 22.2 microg/ml. There was no interference from 32 other antibiotics. The correlation coefficient between the assay and fluorescence polarization immunoassay and direct injection HPLC was 0.982 and 0.985, respectively. The assay required no sample preparation of serum and used only microquantities of an electrophoresis buffer and samples. CONCLUSIONS This assay is cost-effective and suitable for routine clinical use.

Development and validation of a MEKC method for the direct determination of cefozopran in human serum

A method for determining the concentration of cefozopran, a cephem anti-microbial agent which has a broad spectrum, in human serum using micellar electrokinetic capillary chromatography (MEKC) by serum direct injection is developed and the validation of the assays of this method is performed. A borate buffer (25mM; pH 10.0) containing sodium dodecyl sulfate (SDS) (50mM) is used as a run buffer. The electrophoresis of serum samples is carried out at 25kV and the detection of cefozopran at 244nm as its absorption maximum at the cathodic side of the capillary. The migration time of cefozopran is 6.5min. Linearity (0-200mg/l) is good and limit of quantification is 0.5mg/l at a signal-to-noise ratio of 3. Coefficient of variation (CV) of intra-day precision and that of inter-day precision are 2.4-4.0% (7.3-92.0mg/l) and 2.9-7.7% (22.5-71.4mg/l), respectively, and the recovery rate is 92-109%. The detection results of 12 other cephem anti-microbial agents under the analytical conditions of this method show that the migration time of cefmetazole is identical with that of cefozopran, making it impossible to separate these two anti-microbial agents. This method is characterized by the fact that simple and economic determination can be achieved by directly injecting the serum samples of micro-quantities into the capillary.

Method development for determining the antibacterial linezolid in human serum by micellar electrokinetic capillary chromatography

A precise method for determining linezolid concentration in human serum by micellar electrokinetic capillary chromatography has been developed and validated. Serum was deproteinized with acetonitrile and etofylline was used as an internal standard. A borate buffer (pH 10.0; 25 mM) containing sodium dodecyl sulfate (80 mM) was used as a running buffer. Detection was performed at UV253 nm by applying 25 kV voltage to a fused-silica capillary tube. Migration time of linezolid was approximately 14 min. Good linearity (0-100 mg/l) was obtained and the limit of detection was 0.5 mg/l (S/N=3). This technique covered the clinical concentration (4 mg/l) measurement of this drug enough. The intra- and inter-day reproducibility was good. Serum recovery was 95-102%. No interference from other anti-microbial agents was observed. Linezolid after serum deproteinization showed high stability. This method was easy to operate as well as economical as a method for determining linezolid in serum.

Occurrence of heavy chain of 7S IgM half-molecule whose NH2-terminal sequence is identical with that of κ light chain sequence in patients with Waldenstrom macroglobulinemia

We report a rare case of a half molecule 7S IgM (HM 7SIgM) consisting of a unique mu heavy chain and kappa light chain found in blood and urine samples from a patient with primary Waldenstrom macroglobulinemia. A 64kDa abnormal immunoglobulin was detected in serum and urine by immunoblot method, and purified by a two-dimensional SDS-PAGE after separation from IgG and albumin fractions on gel filtration. NH2-terminal amino acid sequence analysis of the heavy chain revealed that residues 1-20 were identical to those of the NH2-terminal region of kappa light chain derived from the same patient. This sequence was then followed by a sequence that could not be identified by a computer homology search on the protein database. Using polypeptide segments obtained from the unique mu chain by digestion with endopeptidase, we identified a sequence spanning from residue 127 in the variable region of the known mu chain to residue 19 in the known CH1 domain and a sequence spanning from residues 67-82 in the heavy chain variable region class II. From these results, we concluded that the 64 kDa protein was an abnormal half molecule 7S IgM consisting of a kappa light chain and a unique mu heavy chain of 35 kDa polypeptide in which the NH2-terminal 20 amino acids were replaced by 20 amino acids derived from the sequence of kappa light chain in the NH2-terminal region.

Quantification of pilsicainide in serum by capillary electrophoresis.

A new method for determining pilsicainide concentration in serum by rapid and selective capillary electrophoresis has been developed and validated. For pretreatment, serum was made alkaline and then extracted with diethyl ether. Procainamide was used as an internal standard. Sodium dihydrogenphosphate buffer (pH 2.29; 0.1 M) was used as a running buffer. A fused-silica capillary tube was loaded with a voltage of 25 kV and detection was performed at UV 200 nm. Good linearity (0-2.5 microg/ml) was obtained with the minimum limit of detection being 0.04 microg/ml serum (signal-to-noise ratio, 3:1). The R.S.D. of within-run reproducibility was 0.798-2.32%, that of between-run reproducibility was 4.74-5.12% and the recovery rate was 61-63%. Disopyramide, another anti-arrhythmic drug, was close to pilsicainide in terms of migration time. This method was applied to determination of pilsicainide in serum samples.

A new type of temperature-dependent serum M protein: a case of IgG-λ type multiple myeloma

Abstract Background: We report a rare case of temperature-dependent serum M protein (thermoprotein), monoclonal IgG1-λ protein isolated from 90-year-old female with advanced multiple myeloma. Methods: M protein was identified in the blood plasma of the patient by immunoelectrophoresis (IEP). To evaluate the types of bonds, the properties of the protein after reduction and chemical treatment were examined. Results: This protein was irreversibly precipitated at or above room temperature when exposed in the air. This protein was redissolved by 30 mmol/l dithiothreitol, 4 mol/l urea, or 8 mmol/l EDTA. Conclusions: Unlike other immunoglobulins reported to date, this data suggests that hydrogen, disulfide, and ionic bonds are involved in the temperature-dependent precipitation of this M protein.