Assessment of the albumin-bilirubin grade as a prognostic factor in patients with non-small-cell lung cancer receiving anti-PD-1-based therapy

Introduction

The albumin-bilirubin (ALBI) grade is a novel indicator of the liver function. Some studies showed that the ALBI grade was a prognostic and predictive biomarker for the efficacy of chemotherapy in cancer patients. The association between the ALBI grade and outcomes in patients with non-small-cell lung cancer (NSCLC) treated with cancer immunotherapy, however, is poorly understood.

Methods

We retrospectively enrolled 452 patients with advanced or recurrent NSCLC who received anti-programmed cell death protein 1 (PD-1)-based therapy between 2016 and 2019 at three medical centers in Japan. The ALBI score was calculated from albumin and bilirubin measured at the time of treatment initiation and was stratified into three categories, ALBI grade 1-3, with reference to previous reports. We examined the clinical impact of the ALBI grade on the outcomes of NSCLC patients receiving anti-PD-1-based therapy using Kaplan–Meier survival curve analysis with log-rank test and Cox proportional hazards regression analysis.

Results

The classifications of the 452 patients were as follows: grade 1, n = 158 (35.0%); grade 2, n = 271 (60.0%); and grade 3, n = 23 (5.0%). Kaplan–Meier survival curve analysis showed that the ALBI grade was significantly associated with progression-free survival and overall survival. Moreover, Cox regression analysis revealed that the ALBI grade was an independent prognostic factor for progression-free survival and overall survival.

Conclusion

The ALBI grade was an independent prognostic factor for survival in patients with advanced or recurrent NSCLC who receive anti-PD-1-based therapy. These findings should be validated in a prospective study with a larger sample size.

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ALBI grade is calculated from albumin and bilirubin.

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We evaluated the impact of ALBI grade on survival in NSCLC patients receiving immune checkpoint inhibitors.

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ALBI grade was an independent prognostic factor for progression-free survival (PFS) and overall survival (OS).

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ALBI grade effectively stratified PFS and OS in patients with performance status 1-3.

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ALBI grade was significantly associated with PFS and OS, regardless of programmed death ligand-1.

MOB1-YAP1/TAZ-NKX2.1 axis controls bronchioalveolar cell differentiation, adhesion and tumour formation

Mps One Binder Kinase Activator (MOB)1A/1B are core components of the Hippo pathway. These proteins, which coactivate LArge Tumour Suppressor homologue kinases, are also tumour suppressors. To investigate MOB1A/B's roles in normal physiology and lung cancer, we generated doxycycline (Dox)-inducible, bronchioalveolar epithelium-specific, null mutations of MOB1A/B in mice (SPC-rtTA/(tetO)₇-Cre/Mob1a^flox/flox/Mob1b^-/-; termed luMob1DKO mice). Most mutants (70%) receiving Dox in utero (luMob1DKO (E6.5-18.5) mice) died of hypoxia within 1 h post-birth. Their alveolar epithelial cells showed increased proliferation, impaired YAP1/TAZ-dependent differentiation and decreased surfactant protein production, all features characteristic of human respiratory distress syndrome. Intriguingly, mutant mice that received Dox postnatally (luMob1DKO (P21-41) mice) did not develop spontaneous lung adenocarcinomas, and urethane treatment-induced lung tumour formation was decreased (rather than increased). Lungs of luMob1DKO (P21-41) mice exhibited increased detachment of bronchiolar epithelial cells and decreased numbers of the bronchioalveolar stem cells thought to initiate lung adenocarcinomas. YAP1/TAZ-NKX2.1-dependent expression of collagen XVII, a key hemidesmosome component, was also reduced. Thus, a MOB1-YAP1/TAZ-NKX2.1 axis is essential for normal lung homeostasis and expression of the collagen XVII protein necessary for alveolar stem cell maintenance in the lung niche.

Evaluation of inosin-5'-monophosphate dehydrogenase activity during maintenance therapy with tacrolimus

OBJECTIVES

The aim of this study was to identify a target range for inosin-5'-monophosphate dehydrogenase (IMPDH) activity in maintenance therapy with tacrolimus (TCL), and to apply the measurement of IMPDH activity to the therapeutic drug monitoring for mycophenolate mofetil (MMF).

METHODS

Eleven patients with renal transplants and 10 healthy volunteers were investigated. All patients were treated with a combination of TCL, steroid and MMF for 2 months after transplantation, and were in stable and good condition. IMPDH activity was determined indirectly by measuring xanthosine 5'-monophophate in cell lysates supplemented with IMP and beta-nicotine adenine dinucleotide using an high-performance liquid chromatography (HPLC) method.

RESULTS

The within-run reproducibility of the assay was excellent, with relative standard deviation (RSD) values of 0.41-4.08%. The mean differences between the spiked concentrations of xanthosine 5'-monophophate and their real values (mean relative errors; MREs) were within a range of 2.66-8.89%, showing good accuracy. The interday RSD values were 1.51-6.12% and MREs ranged from 2.10% to 8.89%. Cell lysates showed a 5-6 nmol/L IC(50) mycophenolic acid (MPA) concentration. TCL, cyclosporine and prednisolone did not affect IMPDH activity. The peak MPA concentration was achieved at 1 h after dosing. IMPDH activity decreased to 75% and 67% at 1 and 2 h after dosing respectively. Therefore, the inhibition rates of MPA against IMPDH activity may be adequate at 25-40% in TCL maintenance therapy.

CONCLUSION

Inosin-5'-monophosphate dehydrogenase activity in cell lysates could be reliably determined by HPLC. A 25-40% inhibition of IMPDH activity may be an appropriate range for preventing rejection with MPF but this requires further validation using larger studies with harder outcomes such as rejection episodes.

Effect of tube voltage on image quality in 64-section multidetector 3D CT angiography: Evaluation with a vascular phantom with superimposed bone skull structures

BACKGROUND AND PURPOSE

Optimal tube voltage and tube current settings are not well established. The purpose of our study was to investigate the image quality on 3D CT angiograms of the brain at various kilovoltage settings by evaluating the depiction of simulated intracranial lesions by using a vascular phantom.

MATERIALS AND METHODS

An anthropomorphic vascular phantom with superimposed bone skull structures was designed to simulate various intracranial aneurysms with aneurysmal blebs. We performed CT angiography by using a 64-detector row CT scanner for various effective tube currents with 4 tube voltages of 80, 100, 120, and 135 kV(p). Simulated aneurysm enhancement and image noise were quantified; SNR and CNR were calculated. The depiction of the simulated aneurysms and blebs on 3D CT angiograms obtained with the volume-rendering technique was subjectively assessed. The effective dose was calculated on the basis of a CTDIw. The results of several protocols were compared by using the Student t test.

RESULTS

At identical doses levels (CTDIw), the mean SNR and CNR at 100 kV(p) were significantly higher than those at 80, 120, and 135 kV(p); and the mean qualitative image score at 100 kV(p) was significantly superior to those at 80 and 135 kV(p).

CONCLUSIONS

Our phantom study suggests that the tube voltage of 100 kV(p) is desirable for cerebral 3D CT angiograms, and the higher or lower kilovoltage settings may result in the degradation in diagnostic image quality.

Reduction of the radiation dose for multidetector row CT angiography of cerebral aneurysms using an edge-preserving adaptive filter: a vascular phantom study

To determine how much the radiation dose can be reduced in multidetector row CTA using a QDS, we performed CTA at various exposure settings using a vascular phantom simulating various aneurysms with superimposed bone skull structures, and postprocessed the image data with QDS. Our results demonstrated that the radiation dose of CTA can be reduced by at least 25% and the image quality for visualizing aneurysms can be preserved by applying the QDS.

[New method for preparing proximal anastomotic system]

Heartstring is a useful device. However, the device failure at the time of loading the seal into the delivery device is a troublesome issue. To avoid this problem, we invent a new method using 2 tourniquets made of 5 mm-wide woven Teflon tapes and plastic tubes. Using our method, the loading procedure became easier and more reliable.

Electrolyzed-reduced water reduced hemodialysis-induced erythrocyte impairment in end-stage renal disease patients

Chronic hemodialysis (HD) patients increase erythrocyte susceptibility to hemolysis and impair cell survival. We explored whether electrolyte-reduced water (ERW) could palliate HD-evoked erythrocyte impairment and anemia. Forty-three patients undergoing chronic HD were enrolled and received ERW administration for 6 month. We evaluated oxidative stress in blood and plasma, erythrocyte methemoglobin (metHb)/ferricyanide reductase activity, plasma metHb, and proinflammatory cytokines in the chronic HD patients without treatment (n=15) or with vitamin C (VC)- (n=15), vitamin E (VE)-coated dialyzer (n=15), or ERW treatment (n=15) during an HD course. The patients showed marked increases (15-fold) in blood reactive oxygen species, mostly H(2)O(2), after HD without any treatment. HD resulted in decreased plasma VC, total antioxidant status, and erythrocyte metHb/ferricyanide reductase activity and increased erythrocyte levels of phosphatidylcholine hydroperoxide (PCOOH) and plasma metHb. Antioxidants treatment significantly palliated single HD course-induced oxidative stress, plasma and RBC PCOOH, and plasma metHb levels, and preserved erythrocyte metHb /ferricyanide reductase activity in an order VC>ERW>VE-coated dialyzer. However, ERW had no side effects of oxalate accumulation easily induced by VC. Six-month ERW treatment increased hematocrit and attenuated proinflammatory cytokines profile in the HD patients. In conclusion, ERW treatment administration is effective in palliating HD-evoked oxidative stress, as indicated by lipid peroxidation, hemolysis, and overexpression of proinflammatory cytokines in HD patients.

Demonstration of reversed flow in segmental branches of the portal vein with hand-held color Doppler ultrasonography after hematopoietic stem cell transplantation

Hepatic veno-occlusive disease (VOD) is a severe complication of hematopoietic stem cell transplantation (SCT). When monitored with hand-held color Doppler ultrasonography during day -7 to +35 around SCT, reversed blood flow in the segmental branches of the portal vein was detected in nine of 56 patients who had undergone SCT. Three of nine patients had clinical evidence of VOD, but six patients did not fulfill the criteria for diagnosis of VOD initially. Two patients progressed to clinical VOD at a later date and the reversed portal flow disappeared with or without treatment for VOD in the other four patients. Monitoring for reversed portal flow with color Doppler ultrasonography may be a useful tool for the early diagnosis of VOD, and may improve prognosis by allowing early initiation of treatment.

A CYP2D6 Phenotype-Genotype Mismatch in Japanese Psychiatric Patients

The aim of the present study was to seek a CYP2D6 genotypic-phenotypic discordance possibility in Japanese patients under psychotropic drug treatment where the CYP2D6 status and pharmacodynamic responses differ from those in Caucasian psychiatric patients. Ninety drug-free, healthy volunteers and 14 patients undergoing psychotropic drug treatment were phenotyped for their individual CYP2D6 activity using dextromethorphan as a probe, and then the metabolic ratio (MR) was calculated. For the genotyping, eight mutant alleles of the CYP2D6 genes were identified. Serum concentrations of two frequently co-medicated psychotropic drugs, biperiden and levomepromazine, were determined by GC/MS. Genotyping revealed no poor metabolizers (PMs) enrolled in our study. Healthy volunteers exhibited an identical phenotype-genotype concordance, whereas 7 of the 14 patients had significantly high (p < 0.05) MRs compared with genotype-matched volunteers. Three of the patients who had the extensive metabolizer (EM) genotype had extremely high MRs and were classified as phenotypic PMs. Five patients plus all of the seven high MR patients were treated with levomepromazine and/or biperiden, respectively. Their mean serum steady-state concentrations were 27.4 and 7.6 ng/ml, respectively. A CYP2D6 phenotype-genotype mismatch (phenocopying) can occur in Japanese psychiatric patients receiving clinical doses of some psychotropic drugs where the prevalence of PMs is low and the pharmacodynamic responses to those drugs are enhanced compared to Caucasian patients.

High-performance liquid chromatographic method for mycophenolic acid and its glucuronide in serum and urine

OBJECTIVE

To develop a simple analytical method for monitoring serum and urine concentrations of mycophenolic acid (MPA), an active metabolic constituent of the immunosuppressive pro-drug mycophenolate mofetil, and its glucuronide.

METHODS

Serum samples were prepared by solid-phase extraction (SPE), while urine samples were simply diluted with water. Serum was added to an SPE cartridge, then washed twice with 5% methanol solution. The analytes were eluted with methanol containing benzoic acid as internal standard for mycophenolic acid glucuronide (MPAG). The resultant eluate was directly injected into a high-performance liquid chromatograph (HPLC) to determine MPAG. For the assay of MPA, the remaining eluate was dried under nitrogen and resolved in a mixture of acetonitrile and 20 mM phosphate buffer (pH 3.0).

RESULTS

The present methods were reproducible and accurate based on the intra- and inter-assay, and had detection limits of 0.225 microg/mL for MPA and 9.0 microg/mL for MPAG. The present methods enabled us to monitor the time course of changes in the concentrations of MPA and MPAG in serum and urine in a patient with a renal transplant during 12 h after ingestion of mycophenolate mofetil.

CONCLUSION

The HPLC method described should be useful for the routine monitoring of serum and urine concentrations of MPA and MPAG during immunosuppressive medication for renal transplantation.

Analysis of nitrogen flow in rice cultivation in CEEF

In order to control the material circulation in the Closed Ecology Experiment Facilities (CEEF), it is necessary to clarify material flow in the Closed Plant Experiment Facility (CPEF) of CEEF. We tried to grow rice plants and measure the nitrogen contents in rice plant and nutrient solution in plant cultivation bed to trace the material balance in CPEF. The measurements were carried out under the condition of 750 ppm (v/v) CO2 at 26/19 degrees C in the plant cultivation room. The measurements showed the absorbed nitrogen amount in plant was less than the outflow nitrogen amount from nutrient solution. This difference between absorbed and outflow quantity reached to 17%.

Simple determination of mycophenolic acid in human serum by column-switching high-performance liquid chromatography

A column-switching high-performance liquid chromatographic analysis was established to monitor the serum concentration of mycophenolic acid, the active metabolite from mycophenolate mofetil administered for the prophylaxis of acute organ rejection in renal transplantation. The system consisted of two pumps for solvent delivery, a column-switching valve, a precolumn, and a reversed-phase analytical column. The present method enabled us to determine MPA by injecting serum samples directly into HPLC without any pretreatment. The mobile phases with different amounts of organic solvent were delivered to the precolumn and analytical column by separate lines, and samples were applied to the precolumn. The column switching valves were switched automatically following the processes for the elimination of protein and the drug analysis. The peak heights of MPA were linearly related to the concentrations (r=0.999) in the range of 0.1-20 micro g/ml, and the limit of quantification was 0.1 micro g/ml (S/N ratio=3). This method was accurate and reproducible on the basis of the results of recovery (94.0-98.0%) and small coefficient of variations of intra and inter-assay (less than 8.3%).

Bending properties of hollow super-elastic Ti-Ni alloy wires and compound wires with other wires inserted

The purpose of this research was to investigate the possible orthodontic application of the hollow super-elastic Ti-Ni alloy wire, which was thought not only to deliver much lower and more continuous orthodontic force than conventional Ti-Ni wires, but also be able to be applied as a compound wire when combined with another wire. The examinations of bending properties were performed by the three-point bending test. The following results were obtained. 1. The hollow wire had lower load in the super-elastic range, smaller load-deflection rate and stress hysteresis in comparison with the conventional wire of the same diameter. 2. The load of the hollow wire was controllable by heat treatment. The stress hysteresis was further decreased by a two-step heat treatment. 3. The compound wire formed by inserting other types of wires into the hollow core exhibited changes in various bending properties such as increased load or load-deflection rate, according to the types and diameters of the inserted wire. The hollow wire delivers much lighter and more continuous orthodontic force, and, through heat treatment or deployment as a compound wire, it is possible to alter various bending properties. Therefore, this hollow wire was evaluated as a promising candidate for orthodontic application.

Anisotropic orthodontic force from the hollow super-elastic Ti-Ni alloy wire by transforming the wire cross-section

The purpose of this research was to devise a method for transforming the cross-section of the hollow super-elastic Ti-Ni alloy round wire and to examine the changes in its bending properties for clinical orthodontic application. The specimen wires were pressed with the use of heated pliers to transform the cross-sectional shape. As a result, transformation of the wire cross-section with super-elasticity was possible. As a verified by cantilever test and three-point bending test of the transformed specimens, a two-dimensional orthodontic force, which was different in each bending direction, was obtained. The hollow wire showed considerably high load level in the long axis along with markedly low load level in the short axis, which was mainly caused by the change in the moment of inertia by transforming the cross-section. It was revealed that, by transforming the wire cross-section of the hollow super-elastic Ti-Ni alloy round wires, anisotropic orthodontic force in bending properties could be obtained with super-elasticity.

Controlled Ecological Life Support System-related activities in Japan

This article provides an overview of current CELSS-related activities in Japan. The status and future plan of the Closed Ecology Experiment Facilities (CEEF), the so-called, "Biosphere-J," are introduced. The Institute for Environment Sciences (ICE) has completed its first construction plan of the Closed Plant Experiment Facility (CPEF) and is now constructing the Closed Geo-Hydrosphere Experiment Facility (CGEF). Next, as one of the most prospective applications of CELSS technologies, introduced is the space-related CELSS research activity in the Space Environment Utilization Frontiers Joint Research Program, which was promoted by Science and Technology Agency (STA) and National Space Development Agency (NASDA) of the Japanese government to encourage the Space Station utilization activities.

Comparison of the kinetic disposition of and serum gastrin change by lansoprazole versus rabeprazole during an 8-day dosing scheme in relation to CYP2C19 polymorphism

BACKGROUND

Little is known about differences in the disposition kinetics and pharmacological effects on gastrin levels between lansoprazole and rabeprazole given in a repeated dosing scheme with respect to the polymorphic CYP2C19.

AIM

To provide preliminary information that should be considered when prescribing proton-pump inhibitors (PPIs) for the treatment of acid-related diseases with reference to the CYP2C/9 genotypic status.

METHODS

Helicobacter pylori-negative healthy volunteers were divided into the following three groups (n = 5 each) on the basis of genotyping for CYP2C19: homozygous (hmEMs) and heterozygous extensive metabolizers (htEMs), and poor metabolizers (PMs). All received once-daily 30-mg doses of lansoprazole or 10-mg doses of rabeprazole during an 8-day course in a crossover manner.

RESULTS

The relative values for the area under the serum concentration-time curve (AUC) of lansoprazole and rabeprazole in the hmEMs, htEMs, and PMs after the final doses were 1:1.7:3.9 and 1:1.7:3.8, respectively. The relative AUCs of gastrin in the hmEMs, htEMs, and PMs were 1.6:2.6:3.1 for lansoprazole and 1.6:2.6:2.9 for rabeprazole, respectively.

CONCLUSION

The disposition kinetic behavior of the two PPIs is co-segregated with CYP2C19. The magnitude of CYP2C19-dependent drug availability in the systemic circulation and resulting gastrin response appears to be fairly similar between the two drugs within the same CYP2C19 genotypic groups after a multiple-dosing regimen.

Genetic polymorphisms and functional characterization of the 5'-flanking region of the human CYP2C9 gene: in vitro and in vivo studies

OBJECTIVE

Genetic polymorphisms were identified in the 5'-flanking region of the human CYP2C9 gene, and their effects on the phenotype were evaluated on the basis of the luciferase reporter gene assay and the in vivo pharmacokinetics of phenytoin.

METHODS

Genetic polymorphisms were screened by polymerase chain reaction-single-strand conformational polymorphism analysis, following sequencing with DNA samples obtained from 50 healthy volunteers and 133 adult epileptic patients. HepG2 hepatoma cells were cotransfected with various sequence patterns of 5'-flanking region-luciferase reporter gene constructs. Pharmacokinetic parameters of phenytoin in relation to the corresponding sequence patterns were estimated by the Bayesian method, and the results were compared with in vitro activities.

RESULTS

Genetic analysis revealed the existence of 7 single nucleotide polymorphisms (SNPs). Allele frequencies of T-->C transition at position -1912 (T-1912C), C-1886G, C-1566T, G-1538A, C-1189T, G-982A, and A-162G were 0.019, 0.019, 0.077, 0.019, 0.579, 0.019, and 0.003, respectively. Some mutations occurred simultaneously, and a total of 6 sequence patterns (patterns 1-6) were observed. The luciferase reporter gene assay indicated that the presence of mutation(s) resulted in a reduction in luciferase activity of 41.4% (pattern 2) to 86.8% (pattern 5) compared with the activity of the wild-type construct. The calculated intrinsic clearance of phenytoin was also lower (up to a 40% reduction for pattern 2) when a mutation(s) was present.

CONCLUSION

In addition to the two major mutations in the coding region (CYP2C9*2 and CYP2C9*3 ), mutations in the 5'-flanking region of the human CYP2C9 gene appear to contribute to the large interindividual variability in drug metabolism activity.

Early changes of bone histology and circulating markers of bone turnover after parathyroidectomy in hemodialysis patients with severe hyperparathyroidism

AIMS

There have so far been no reports on the changes in bone histology in the early period after parathyroidectomy and autografting (PTX-AG). We investigated the effects of PTX-AG on bone histology during the initial 12 weeks after undergoing these surgical procedures.

MATERIALS AND METHODS

We performed bone histomorphometry 3 times (before as well as 4 and 12 weeks after PTX-AG) in 6 patients and 2 times (before and 4 weeks after PTX-AG) in 3 hemodialysis patients. In addition, the circulating parameters of bone metabolism were also assessed before and after PTX-AG in all 9 patients. The changes in the histomorphometric (static) parameters between pre-surgery and 4 weeks after surgery and those between 4 weeks and 12 weeks after surgery were assessed by the t-test while changes in the circulating parameters of bone metabolism were analyzed by Friedman's test.

RESULTS

Bone formation parameters including carboxy terminal propeptide of human type I procollagen (PICP), alkaline phosphatase (ALP) and intact osteocalcin (i-OC) were all extremely high before surgery. These parameters initially increased after PTX-AG and thereafter gradually declined. In contrast, the circulating bone resorption parameters including tartrate-resistant acid phosphatase (TRAP) and deoxypyridinoline (Dpyr) were also extremely high at baseline but markedly declined after operation. Osteoid-related parameters including osteoid volume (OV/BV), osteoid surface (OS/BS), and osteoid thickness (O.Th) all initially increased at 4 weeks after PTX-AG. In contrast, osteoblast surface (Ob.S/BS), osteoclast surface (Oc.S/BS), eroded surface (ES/BS), and fibrosis volume (Fb.V/TV) all decreased at 4 weeks after surgery, while Ob.S/BS decreased further at 12 weeks in cases 1-6. Although bone mineralization was ongoing at 4 weeks after surgery, both the mineral apposition rate (MAR) and bone formation rate (BFR) remained below the mean for normal individuals.

CONCLUSIONS

The circulating bone formation parameters and osteoid-related parameters showed an initial increase after PTX-AG. The concomitant decline in the circulating bone resorption parameters reflected the reduction in bone resorption. BFR decreased, but bone mineralization did not stop after PTX-AG.

Expression of P-glycoprotein in human placenta: relation to genetic polymorphism of the multidrug resistance (MDR)-1 gene

To evaluate whether mutations in the human multidrug resistance (MDR)-1 gene correlate with placental P-glycoprotein (PGP) expression, we sequenced the MDR-1 cDNA and measured PGP expression by Western blotting in 100 placentas obtained from Japanese women. Nine single nucleotide polymorphisms (SNPs) were observed with an allelic frequency of 0.005 to 0.420. Of these SNPs, G2677A (allelic frequency = 0.18) and G2677T (0.39) in exon 21 were associated with an amino acid conversion from Ala to Thr and to Ser, respectively. Sixty-one of 65 samples (93.8%), which had a C3435T allele, also had a mutant G2677(A,T) allele, suggesting an association between the two SNPs. Correlations of mutations with expression levels were observed; individuals having the G2677(A,T) and/or T-129C (p < 0.05) allele had less placental PGP. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)-based genotyping tests were developed for the detection of these SNPs. The PCR, in which genomic DNAs obtained from healthy subjects (n = 48) are used as samples, was successful. The frequency of mutations in placental cDNA was identical with that in genomic DNA. When genotype results were compared between Caucasians and Japanese, ethnic differences in the frequency of polymorphism in the MDR-1 gene were suspected. Although it remains to be determined whether these SNPs influence the pharmacokinetic and dynamic properties of clinically useful drugs that are substrates of PGP, the polymorphism of the MDR-1 gene presented here may provide useful information in in vivo study of these issues.

P-hydroxylation of phenobarbital: relationship to (S)-mephenytoin hydroxylation (CYP2C19) polymorphism

The aim of the current study was to compare the pharmacokinetics of phenobarbital (PB) in extensive metabolizers (EMs) and poor metabolizers (PMs) of S-mephenytoin. Ten healthy volunteers (5 EMs and 5 PMs) were given 30 mg PB daily for 14 days. PB and p-hydroxyphenobarbital (p-OHPB) in serum and urine were measured by high-performance liquid chromatography (HPLC). Urinary excretion (12.5% versus 7.7%) and formation clearance (29.8 versus 21.1 mL/h) of p-OHPB, one of the main metabolites of PB, were significantly lower (p < .05) in PMs than in EMs. However, area under the serum concentration-time curve (153.3 in the EMs versus 122.9 microg x h/mL in the PMs), total (210.8 versus 254.9 mL/h) and renal clearance (53.1 versus 66.1 mL/h) of PB were identical between the two groups. To compare the inducibility of CYP2C19, mephenytoin was also given prior to and on the last day of PB treatment. The urinary level of 4'-hydroxymephenytoin was analyzed by a validated gas chromatograpy/mass spectrometry (GC/MS) method. The mephenytoin hydroxylation index did not change in either EMs (1.42 versus 1.42) or PMs (341.4 versus 403.5), showing that CYP2C19 was not induced by treatment with PB. These results indicated that the p-hydroxylation pathway of PB co-segregates with the CYP2C19 metabolic polymorphism. However, the overall disposition kinetics of PB were not different between EMs and PMs, and therefore polymorphic CYP2C19 seems have no major clinical implications.

Treatment of overactive bladder with modified intravesical oxybutynin chloride

Intravesical oxybutynin chloride has been reported to be effective for overactive bladder, although sometimes the efficacy does not last long enough. To improve this deficiency, we report the effects of intravesical oxybutynin chloride with hydroxypropylcellulose (modified intravesical oxybutynin). Modified intravesical oxybutynin (5 mg/10 mL, twice a day) was administered to six overactive bladder patients for more than 1 year (two men and four women; average age, 56.5 years) who did not respond to oral anticholinergic agents and electric stimulation. Cystometography (CMG) was performed before, 2 hours, and 1 week after the start of modified intravesical oxybutynin. In addition, plasma levels of oxybutynin and its active metabolite, N-desethyl-oxybutynin (DEOB), were measured by high-performance liquid chromatography before, 1, 2, and 4 hours after the initial treatment of modified intravesical oxybutynin. CMG studies revealed that two of the six patients did not demonstrate uninhibited contractions 1 week after the treatment and that cystocapacity of before, 2 hours, and 1 week after the initial modified intravesical oxybutynin was 141.8+/-15.3, 210.0+/-35.5, and 305.0+/-21.3 mL, respectively. Plasma levels of oxybutynin and DEOB before, 1, 2, and 4 hours after the first instillation of modified intravesical oxybutynin were oxybutynin; not detected, 8.8+/-2.5, 6.8+/-1.1, 3.0+/- 1.0 ng/ml, and DEOB; not detected, 4.2+/-1.3, 6.4+/-1.7, 5.1+/- 1.4 ng/ml, respectively. No side effects were observed in any of the patients. Modified intravesical oxybutynin is an effective and safe therapy option for overactive bladder patients who do not respond to other treatments such as oral anticholinergic agents and electric stimulation.

Application of crop gas exchange and transpiration data obtained with CEEF to global change problem

In order to predict carbon sequestration of vegetation with the future rise in atmospheric CO2 concentration, [CO2] and temperature, long term effects of high [CO2] and high temperature on responses of both photosynthesis and transpiration of plants as a whole community to environmental parameters need to be elucidated. Especially in the last decade, many studies on photosynthetic acclimation to elevated [CO2] at gene, cell, tissue or leaf level for only vegetative growth phase (i.e. before formation of reproductive organs) have been conducted all over the world. However, CO2 acclimation studies at population or community level for a whole growing season are thus far very rare. Data obtained from repeatable experiments at population or community level for a whole growing season are necessary for modeling carbon sequestration of a plant community. On the other hand, in order to stabilize material circulation in the artificial ecological system of Closed Ecology Experiment Facilities (CEEF), it is necessary to predict material exchange rates in the biological systems. In particular, the material exchange rate in higher plant systems is highly variable during growth periods and there is a strong dependence on environmental conditions. For this reason, dependencies of both CO2 exchange rate and transpiration rate of three rice populations grown from seed under differing conditions of [CO2] and day/night air temperature (350 microL CO2 L-1, 24/17 degrees C (population A); 700 microL CO2 L-1, 24/17 degrees C (population B) and 700 microL CO2 L-1, 26/19 degrees C (population C)) upon PPFD, leaf temperature and [CO2] were investigated every two weeks during whole growing season. Growth of leaf lamina, leaf sheath, panicle and root was also compared. From this experiment, it was elucidated that acclimation of instantaneous photosynthetic response of rice population to [CO2] occurs in vegetative phase through changes in ratio of leaf area to whole plant dry weight, LAR. But, in reproductive growth phase (i.e. after initiation of panicle formation), the difference between photosynthetic response to [CO2] of population A and that of population B decreased. Although LAR of population C was almost always less than that of population A, there was no difference between the photosynthetic response to [CO2] of population A at 24 degrees C and that of population C at 26 degrees C for its whole growth period. These results are useful to make a model to predict carbon sequestration of rice community, which is an important type of vegetation especially in Asia in future global environmental change.

[Studies on the efficient syntheses of the drug metabolites]

This review summarizes our recent findings in the syntheses of drug metabolites. The metabolites of Grepafloxacin (1) and OPC-14117 (10) were prepared from the common intermediates (5) and (21), respectively. Moreover, treatment of 10 with a model P450 system led to a benzyl alcohol derivative (11) in one step. OPC-31260 (22) was efficiently N-dealkylated using several metalloporphyrins with oxidants to afford three metabolites (23-25). In addition, I succeeded in obtaining the metabolite (23) in high yield from N-oxide (26) not only as an oxygen donor but also as a substrate, there after, in the model P450 system. Optically active metabolites of OPC-29030 (27) were prepared by enzyme-catalyzed enantioselective transesterification of racemic sulfinyl metabolites. On the other hand, a chiral 1,1'-bi-2-naphthol derivative (38a) was found to be an efficient asymmetric acylating agent for a secondary alcohol (36) which is a valuable intermediate for preparing optically active metabolites of 22. Furthermore, metabolites (45) and (47) of OPC-21268 (44) were prepared using SmI2-induced cyclization and oxidative decarboxylation with Pb(OAc)4 as key steps, respectively.

Catalytic activity of three variants (Ile, Leu, and Thr) at amino acid residue 359 in human CYP2C9 gene and simultaneous detection using single-strand conformation polymorphism analysis

This study evaluated the catalytic activity of three variants (Ile, Leu, and Thr) at codon 359 of CYP2C9 enzymes expressed in a yeast cDNA expression system, and then established single-strand conformation polymorphism (PCR-SSCP) analysis for simultaneous detection as a screening method. Diclofenac was used for the in vitro experiment, and its hydroxy metabolite (4'-hydroxydiclofenac) was measured by HPLC. To discuss the in vivo effect of the Thr359 variant on the pharmacokinetics of phenytoin, a case report is presented. The efficiency of the SSCP method was evaluated by analyzing DNA samples from a homozygote for Ile359 and a heterozygote for Leu359 or Thr359. To evaluate the interaction between the P450 level and reductase activity, two batches of the Thr359 variant with a different P450:reductase activity ratio (1:4.0 and 1:1.4) were used. The in vitro study revealed that recombinant Ile359, Leu359, and Thr359 (2 batches) possessed a mean Km of 2.0, 16.5 and (3.8 and 2.9) micromol and Vmax of 12.4, 17.9 and (4.4 and 5.1) nmol/min/nmol P450, respectively. Although the magnitude of the change in catalytic efficiency for the Thr359 variant was close to that of the Leu359 variant, the effect of the two variants on diclofenac 4'-hydroxylation appears to be different because Leu359 variant was associated with a high Km, and Thr359 with a low Vmax. No significant differences in the kinetic data were observed between the two Thr359 enzymes, suggesting that low reductase activity in the Thr359 enzyme was not a major determinant in the present in vitro experiment. Estimated pharmacokinetic parameters of phenytoin obtained by the Bayesian method in an epileptic patient who was a heterozygote carrier for Thr359 variant were: Km = 6.45 microg/mL, Vmax = 5.77 mg/kg/d, and Vmax/Km = 0.89 L/kg/day. The Vmax/Km value in this patient was similar to the population mean value (0.90 L/kg/day) in Japanese heterozygotes for the Leu359 variant. Results for PCR-SSCP were in complete agreement with those obtained using established methods. Thus, the PCR-SSCP approach is useful for identifying these three variants of the CYP2C9 gene.

Lack of differences in diclofenac (a substrate for CYP2C9) pharmacokinetics in healthy volunteers with respect to the single CYP2C9*3 allele

OBJECTIVES

Evidence exists to suggest that diclofenac is metabolised by CYP2C9. The present study was undertaken in order to evaluate the effect of the single CYP2C9*3 variant on drug metabolism using diclofenac as a probe drug.

METHODS

A single dose of diclofenac was administered orally to 12 healthy subjects in whom the genotype of CYP2C9 had been determined previously. The disposition kinetics of diclofenac were compared between homozygotes for the wild type (CYP2C9*1/*1, n = 6) and heterozygotes for the Leu359 variant (CYP2C9*1/*3, n = 6).

RESULTS

For diclofenac, the following kinetic parameters were observed in the CYP2C9*1/*1 and CYP2C9*1/*3 subjects, respectively (mean +/- SD): apparent oral clearance (ml/kg/h) 355.8 +/- 56.9 and 484.4 +/- 155.3; area under plasma concentration time curve (microg h/ml) 2.7 +/- 0.7 and 1.9 +/- 0.6. The formation clearance of 4'-hydroxydiclofenac (ml/kg/h) was 63.6 +/- 19.1 in the CYP2C9*1/*1 subjects compared with 75.9 +/- 27.6 in the CYP2C9*1/*3 subjects. There were no significant differences in any of the kinetic parameters for either diclofenac disposition or formation clearance of 4'-hydroxydiclofenac between the two genotype groups.

CONCLUSION

Since the disposition kinetics of diclofenac does not change in subjects with the single CYP2C9*3 mutant allele, it is suggested that the effects of CYP2C9 polymorphisms on the drug metabolism tend to be substrate specific.

CYP2C19 polymorphism effect on phenobarbitone. Pharmacokinetics in Japanese patients with epilepsy: analysis by population pharmacokinetics

OBJECTIVE

The aim of this study was to clarify the effect of genetic polymorphisms of CYP2C19 on the pharmacokinetics of phenobarbitone (PB) using a nonlinear mixed-effects model (NONMEM) analysis in Japanese adults with epilepsy.

METHODS

A total of 144 serum PB concentrations were obtained from 74 subjects treated with both PB and phenytoin but without valproic acid. All patients were classified into three groups by CYP2C19 genotyping: G1, G2 and G3 were homozygous for the wild type of CYP2C19 (*1/*1), heterozygous extensive metabolizers (EMs), (*1/*2 or *1/*3), and poor metabolizers (PMs), (*2/*2, *2/*3), respectively. All data were analyzed using NONMEM to estimate pharmacokinetic parameters of PB with respect to the CYP2C19 genotype.

RESULTS

Thirty-three patients belonged to G1 (44.6%), 35 to G2 (47.3%), and 6 to G3 (8.1%). The total clearance (CL) of PB significantly decreased by 18.8% in PMs (G3) relative to EMs (G1 and G2). The CL tended to be lower in G2 than in G1.

CONCLUSION

In this study, we first demonstrated the effect of the CYP2C19 polymorphism on pharmacokinetics of PB by genotyping. The contribution of other metabolic enzymes in the metabolism of PB in humans remains to be elucidated; however, it appears that the disposition of PB is mediated in part by this enzyme. The estimated population clearance values in the three genotype groups can be used to predict the PB dose required to achieve an appropriate serum concentration in an individual patient.

Integration test project of CEEF--a test bed for Closed Ecological Life Support Systems

CEEF (Closed Ecology Experiment Facilities) were installed at Rokkasho village in northern Japan, for the purpose of clarifying life-support mechanisms in a completely closed space, such as a Lunar or Mars base. An integration test using the Closed Plantation Experiment Facility and Closed Animal Breeding & Habitation Experiment Facility is needed before conducting an entire closed experiment including plants, animals and humans. These integration tests are planned to be conducted step by step from fiscal 2001 to 2008.

Susceptibility to neuroleptic malignant syndrome in Parkinson's disease

OBJECTIVE

To determine susceptibility to neuroleptic malignant syndrome (NMS) in patients with PD in relation to central monoamine metabolism.

METHODS

CSF levels of homovanillic acid (HVA), 3-methoxy-4-hydroxy phenyletilene glycol (MHPG), and 5-hydroxyindole acetic acid (5-HIAA) were assayed in 98 PD patients (mean age, 77.2 years), including 11 patients with a prior NMS-like episode, by high-performance liquid chromatography with electrochemical detection.

RESULTS

Patients with a previous NMS-like episode had worse parkinsonian disability as measured by Hoehn & Yahr scale (3.7 +/- 0.8 versus 3.0 +/- 1.1; p = 0.038) and lower CSF HVA levels (20.9 +/- 17.3 versus 44.7 +/- 22.2 ng/mL; p = 0.001) compared to those without, despite similar age, disease duration, and daily dosages of antiparkinsonian drugs between groups. Logistic regression analysis showed that the CSF HVA level (p = 0.008), but not 5-HIAA level (p = 0.621), was significantly and independently related to NMS, and that the MHPG level (p = 0.070) was tendentially associated with the disorder. Odds ratios (95% confidence intervals) corresponding to 10 ng/mL increment in CSF HVA, MHPG, and 5-HIAA levels were 0.30 (0.13 to 0.73), 4.03 (0.89 to 18.2) and 1.29 (0.47 to 3.58), respectively.

CONCLUSIONS

Central dopaminergic and possible noradrenergic activity contributes to NMS development in an elderly population of PD patients. Measuring CSF levels of monoamine metabolites may provide a means for identifying NMS susceptibility in PD patients.

Reliability of the omeprazole hydroxylation index for CYP2C19 phenotyping: possible effect of age, liver disease and length of therapy

AIMS

To evaluate the reliability of the omeprazole hydroxylation index as a marker for polymorphic CYP2C19 activity in a Japanese population of healthy young subjects (n = 78) and patients with peptic ulcer (n = 72).

METHODS

Healthy subjects were administered a single dose of omeprazole (20 mg), whereas patients received 20 mg daily for at least 1 week. The ratio of the serum concentration of omeprazole to hydroxyomeprazole at 3 h postdose was determined and used as a measure of CYP2C19 activity. The CYP2C19 wild type (wt) gene and four mutant alleles associated with the poor metaboliser phenotype of (S)-mephenytoin, CYP2C19*2 in exon 5, CYP2C19*3 in exon 4, CYP2C19m4 in exon 9, and CYP2C19m3 in the initial codon were analysed.

RESULTS

In the healthy volunteer study there was complete concordance between genotype and phenotype. However, eight of the patients who had the EM genotype had a high value for their hydroxylation index, and were classified as phenotypic PMs. No CYP2C19m4 and CYP2C19m3 mutations were detected in the eight mismatched patients. They were all genotypic heterozygous EMs, elderly (> or = 65 years) and/or had hepatic disease. Therefore, impaired CYP2C19 activity combined with partial saturation of omeprazole metabolism during multiple dosing may have contributed to the discrepancy between CYP2C19 genotyping and phenotyping.

CONCLUSION

Although omeprazole has been used instead of mephenytoin as a probe for polymorphic CYP2C19, it does not appear to be reliable enough for clinical application in Japanese patients.

The effects of genetic polymorphisms of CYP2C9 and CYP2C19 on phenytoin metabolism in Japanese adult patients with epilepsy: studies in stereoselective hydroxylation and population pharmacokinetics

PURPOSE

The aim of this study was to clarify the effects of genetic polymorphisms of cytochrome P450 (CYP) 2C9 and 2C19 on the metabolism of phenytoin (PHT). In addition, a population pharmacokinetic analysis was performed.

METHODS

The genotype of CYP2C9 (Arg144/Cys, Ile359/Leu) and CYP2C19(*1, *2 or *3) in 134 Japanese adult patients with epilepsy treated with PHT were determined, and their serum concentrations of 5-(4-hydroxyphenyl)-5-phenylhydantoin (p-HPPH) enantiomers, being major metabolites of PHT, were measured. A population pharmacokinetic analysis (NONMEM analysis) was performed to evaluate whether genetic polymorphism of CYP2C9/19 affects the clinical use of PHT by using the 336 dose-serum concentration data.

RESULTS

The mean maximal elimination rate (Vmax) was 42% lower in the heterozygote for Leu359 allele in CYP2C9, and the mean Michaelis-Menten constants (Km) in the heterozygous extensive metabolizers and the poor metabolizers of CYP2C19 were 22 and 54%, respectively, higher than those without the mutations in CYP2C9/19 genes. (R)- and (S)-p-HPPH/PHT ratios were lower in patients with mutations in CYP2C9 or CYP2C19 gene than those in patients without mutations.

CONCLUSIONS

Although the hydroxylation capacity of PHT was impaired with mutations of CYP2C9/19, the impairment was greater for CYP2C9. In view of the clinical use of PHT, two important conclusions were derived from this population study. First, the serum PHT concentration in patients with the Leu359 allele in CYP2C9 would increase dramatically even at lower daily doses. Second, the patients with CYP2C19 mutations should be treated carefully at higher daily doses of PHT.

Electrolyzed-reduced water scavenges active oxygen species and protects DNA from oxidative damage

Active oxygen species or free radicals are considered to cause extensive oxidative damage to biological macromolecules, which brings about a variety of diseases as well as aging. The ideal scavenger for active oxygen should be 'active hydrogen'. 'Active hydrogen' can be produced in reduced water near the cathode during electrolysis of water. Reduced water exhibits high pH, low dissolved oxygen (DO), extremely high dissolved molecular hydrogen (DH), and extremely negative redox potential (RP) values. Strongly electrolyzed-reduced water, as well as ascorbic acid, (+)-catechin and tannic acid, completely scavenged O.-2 produced by the hypoxanthine-xanthine oxidase (HX-XOD) system in sodium phosphate buffer (pH 7.0). The superoxide dismutase (SOD)-like activity of reduced water is stable at 4 degrees C for over a month and was not lost even after neutralization, repeated freezing and melting, deflation with sonication, vigorous mixing, boiling, repeated filtration, or closed autoclaving, but was lost by opened autoclaving or by closed autoclaving in the presence of tungsten trioxide which efficiently adsorbs active atomic hydrogen. Water bubbled with hydrogen gas exhibited low DO, extremely high DH and extremely low RP values, as does reduced water, but it has no SOD-like activity. These results suggest that the SOD-like activity of reduced water is not due to the dissolved molecular hydrogen but due to the dissolved atomic hydrogen (active hydrogen). Although SOD accumulated H2O2 when added to the HX-XOD system, reduced water decreased the amount of H2O2 produced by XOD. Reduced water, as well as catalase and ascorbic acid, could directly scavenge H2O2. Reduce water suppresses single-strand breakage of DNA b active oxygen species produced by the Cu(II)-catalyzed oxidation of ascorbic acid in a dose-dependent manner, suggesting that reduced water can scavenge not only O2.- and H2O2, but also 1O2 and .OH.

Toxohormones responsible for cancer cachexia syndrome in nude mice bearing human cancer cell lines

Toxohormones are tumor-derived factors that induce cancer cachexia syndrome in tumor-bearing animals. Nude mice bearing tumors induced by eight human cancer cell lines with this activity were studied for cytokine production and expression of a newly identified gene, ob, which has the ability to control body weight. A melanoma cell line, SEKI, and a neuroepithelioma cell line, NAGAI, produced a large amount of the cytokine, leukemia-inhibitory factor (LIF). A uterine carcinoma cell line, Yumoto, produced a large amount of interleukin 6 (IL-6), and an oral cavity carcinoma cell line, OCC-1C, concomitantly produced LIF, IL-6, and IL-11. Reverse transcription polymerase chain reaction studies revealed that ob gene mRNA was not expressed in any of these cell lines, suggesting that the gene does not have a role as a tumor product responsible for cancer cachexia in this model. These findings suggest that in four of eight animal models in which cancer cachexia syndrome developed, LIF, IL-6, or possibly IL-11 produced by cancer cells may be toxohormones, but in the remaining four cancer cell lines the mechanism responsible for cachexia syndrome remains unknown.

[Monoamine imbalance of the central nervous system in a case of Shy-Drager syndrome with recurrent attacks of a neuroleptic malignant syndrome]

A 79-year-old male suffering from Shy-Drager syndrome was treated with a daily dosage of 300 mg of L-threo-3,4-dihydroxyphenylserine (L-DOPS). He developed a neuroleptic malignant syndrome (NMS) like state 1 month after teh initiation of L-DOPS therapy. And recurrent attacks of NMS occurred subsequently despite discontinuation of L-DOPS administration. We measured homovanillic acid (HVA), 3 methoxy 4 hydroxyphenylethylenglycol (MHPG), and 5-hydroxyindoleacetic acid (5-HIAA) in this corrected brospinal fluid (CSF), both during his 2 attacks of NMS and after recovery. The HVA and 5 HIAA levels after recovery were low compared with those in age-matched normal controls. However, his levels in the active phase were not different from those after recovery. In contrast, MHPG levels were elevated and his HVA/MHPG ratios decreased in the active phase compared with those in the recovery phase. The results indicate that his symptoms of NMS are attributed to the imbalance between dopamine and noradrenalin rather than the dopamine receptor blockade in the central nervous system. We suggest further evaluations of CSF monoamine metabolites in similar cases to determine the pathogenesis of NMS.

Triple paraneoplastic syndrome of hypercalcemia, leukocytosis and cachexia in two human tumor xenografts in nude mice

Nude mice bearing the human oral cavity carcinoma cell line OCC-1, and the lung cancer cell line LC-1, developed a triple paraneoplastic syndrome consisting of hypercalcemia, cachexia and leukocytosis. All of these abnormalities disappeared rapidly after surgical resection of the tumors, suggesting their ectopic humoral nature. Search for the factors responsible for the respective abnormalities revealed that the production of parathyroid hormone-related protein and colony-stimulating factors (CSFs), mainly granulocyte-CSF, by the tumors could explain the hypercalcemia and leukocytosis, respectively. With regard to the severe cachexia, the production of two cachexia-associated cytokines, interleukin-6 and leukemia inhibitory factor, was able to explain the syndrome in OCC-1 bearing nude mice; however, the factor responsible in LC-1 bearing nude mice could not be identified. The triple paraneoplastic syndrome that developed in these two animal models could be explained partly by concomitant production of the peptide hormone and cytokines by cancer cells. These animal models may be very useful for the evaluation of diagnostic and therapeutic modalities for humoral abnormalities.

In-line filter occlusion during intravenous delivery of injectable menatetrenone (vitamin K2)

Filter occlusion during intravenous infusion of injectable menatetrenone in an electrolyte fluid was examined. The menatetrenone concentration and its emulsion droplet size were not changed by in-line filtration. However, particle counts in the admixed solution and examination of scanning electron micrographs of the surface of the filter membrane indicated that particle formation occurred immediately after the admixture of menatetrenone injection with Hicaliq No. 2, but not with 5% glucose injection. This may be due to the interaction of excess lecithin in the emulsion with the electrolyte. Filter occlusion also occurred with the admixture of menatetrenone-free emulsion and Hicaliq No. 2, but not with 5% glucose injection. These findings indicate that injectable menatetrenone should not be admixed with electrolyte fluids.

Instability of standard calibrators may be involved in overestimating vancomycin concentrations determined by fluorescence polarization immunoassay

Fluorescence polarization immunoassay (FPIA) is widely used to determine serum vancomycin concentrations, and it has been shown to over-estimate vancomycin concentrations in sera from renally impaired patients. This phenomenon has generally been thought to result from interference by vancomycin crystalline degradation products (CDP-1). In this study, we confirmed that serum vancomycin concentrations in various patients determined by FPIA were higher than those determined by high-performance liquid chromatography (HPLC) or enzyme multiplied immunoassay (EMIT). However, the quantitative differences in the serum vancomycin concentrations determined by FPIA versus HPLC were higher than the CDP-1 concentrations, even when the cross-reactivity of FPIA to CDP-1 is assumed to be 100%. When the vancomycin calibrators for FPIA were stored at 4 degrees C for 30 days, their concentrations determined by FPIA and HPLC decreased by 14 and 20%, respectively, and CDP-1 corresponding to 20% of primary vancomycin was formed. When stored at 25 degrees C, the degradation of vancomycin was more marked. We concluded that not only the cross-reactivity of FPIA to CDP-1 but also the instability of calibrators may cause the overestimation of serum vancomycin concentrations determined by FPIA.

Circulating parathyroid hormone-related protein (109-141) in malignancy-associated hypercalcemia

For differential diagnosis between hypercalcemia-induced bone metastasis and humoral hypercalcemia of malignancy (HHM), serum parathyroid hormone-related protein (PTHrP) concentrations were measured in normal subjects and patients with malignancy-associated hypercalcemia according to the presence or absence of bone metastasis, using a new sensitive PTHrP(109-141) radioimmunoassay system. The serum PTHrP(109-141) levels in all of 14 patients without bone metastasis were significantly higher than those in normal subjects. However, in four patients with hypercalcemia associated with bone metastasis the levels were nearly the same as those in normal subjects. The time course in two hypercalcemic patients with esophageal carcinoma revealed that serum PTHrP(109-141) levels were elevated before hypercalcemia developed and that changes in PTHrP(109-141) and corrected serum calcium levels were significantly correlated. These findings suggest that determination of serum PTHrP(109-141) may be clinically important not only for differential diagnosis of HHM but also as a useful predictive marker of hypercalcemia.