Medication-related osteonecrosis of the jaw leading to sepsis in a patient with rheumatoid arthritis: A case report and clinical implications

Key Clinical Message

Chronic use of bisphosphonates, in combination with immunosuppressive therapy, increases the risk of jaw osteonecrosis. When sepsis occurs in patients receiving bisphosphonate, osteonecrosis of the jaw should be considered a potential source of infection.

Abstract

Reports of medication-related osteonecrosis of the jaw (MRONJ) accompanied by sepsis are limited. A 75-year-old female patient with rheumatoid arthritis, receiving treatment with bisphosphonate and abatacept, developed sepsis secondary to MRONJ. When sepsis occurs in patients receiving bisphosphonate, osteonecrosis of the jaw should be considered a potential source of infection.

Mass-resolved ion measurement by particle counting analysis for characterizing relativistic ion beams driven by lasers

Particle counting analysis is a possible way to characterize GeV-scale, multi-species ions produced in laser-driven experiments. We present a multi-layered scintillation detector to differentiate multi-species ions of different masses and energies. The proposed detector concept offers potential advantages over conventional diagnostics in terms of (1) high sensitivity to GeV ions, (2) realtime analysis, and (3) the ability to differentiate ions with the same charge-to-mass ratio. A novel choice of multiple scintillators with different ion stopping powers results in a significant difference in energy deposition between the scintillators, allowing accurate particle identification in the GeV range. Here, we report a successful demonstration of particle identification for heavy ions, performed at the Heavy Ion Medical Accelerator in Chiba. In the experiment, the proposed detector setup showed the ability to differentiate particles with similar atomic numbers, such as C⁶⁺ and O⁸⁺ ions, and provided an excellent energy resolution of 0.41%-1.2% (including relativistic effect, 0.51%--1.6%).

A multi-stage scintillation counter for GeV-scale multi-species ion spectroscopy in laser-driven particle acceleration experiments

Particle counting analysis (PCA) with a multi-stage scintillation detector shows a new perspective on angularly resolved spectral characterization of GeV-scale, multi-species ion beams produced by high-power lasers. The diagnosis provides a mass-dependent ion energy spectrum based on time-of-flight and pulse-height analysis of single particle events detected through repetitive experiments. With a novel arrangement of multiple scintillators with different ions stopping powers, PCA offers potential advantages over commonly used diagnostic instruments (CR-39, radiochromic films, Thomson parabola, etc.) in terms of coverage solid angle, detection efficiency for GeV-ions, and real-time analysis during the experiment. The basic detector unit was tested using 230-MeV proton beam from a synchrotron facility, where we demonstrated its potential ability to discriminate major ion species accelerated in laser-plasma experiments (i.e., protons, deuterons, carbon, and oxygen ions) with excellent energy and mass resolution. The proposed diagnostic concept would be essential for a better understanding of laser-driven particle acceleration, which paves the way toward all-optical compact accelerators for a range of applications.

The suppressive effect on CD4 T cell alloresponse against endothelial HLA-DR via PD-L1 induced by anti-A/B ligation

While donor-specific human leukocyte antigen (HLA) antibodies are a frequent cause for chronic antibody-mediated rejection in organ transplantation, this is not the case for antibodies targeting blood group antigens, as ABO-incompatible (ABO-I) organ transplantation has been associated with a favorable graft outcome. Here, we explored the role of CD4 T cell-mediated alloresponses against endothelial HLA-D-related (DR) in the presence of anti-HLA class I or anti-A/B antibodies. CD4 T cells, notably CD45RA-memory CD4 T cells, undergo extensive proliferation in response to endothelial HLA-DR. The CD4 T cell proliferative response was enhanced in the presence of anti-HLA class I, but attenuated in the presence of anti-A/B antibodies. Microarray analysis and molecular profiling demonstrated that the expression of CD274 programmed cell death ligand 1 (PD-L1) increased in response to anti-A/B ligation-mediated extracellular signal-regulated kinase (ERK) inactivation in endothelial cells that were detected even in the presence of interferon-γ stimulation. Anti-PD-1 antibody enhanced CD4 T cell proliferation, and blocked the suppressive effect of the anti-A/B antibodies. Educated CD25⁺ CD127^- regulatory T cells (edu.T_regs ) were more effective at preventing CD4 T cell alloresponses to endothelial cells compared with naive T_reg ; anti-A/B antibodies were not involved in the T_reg -mediated events. Finally, amplified expression of transcript encoding PD-L1 was observed in biopsy samples from ABO-I renal transplants when compared with those from ABO-identical/compatible transplants. Taken together, our findings identified a possible factor that might prevent graft rejection and thus contribute to a favorable outcome in ABO-I renal transplantation.

P1671Subclinical persistent hemolysis may affect late renal function deterioration after HeartMateII implantation

Background

Late renal function dysfunction is an increasingly recognized complication in continuous flow left ventricular assist device (CF-LVAD) patients. Although hemolysis is prevalent in CF-LVAD patients and hemolysis may deteriorate renal function, the influence of persistent hemolysis on renal function in CF-LVAD patients remains to be investigated.

Purpose

To investigate the influence of persistent hemolysis on renal function in CF-LVAD patients, using lactate dehydrogenase (LDH) as a sensitive marker of hemolysis.

Methods

Excluding patients who died or underwent pump exchange for pump thrombosis, we retrospectively reviewed 65 consecutive adults who underwent HeartMateII implantation in our center from May 2011 to October 2017. Patient characteristics, chronotropic change of estimated glomerular filtration rate (eGFR) and LDH values weekly for 4 weeks and every 4 weeks between 4 and 48 weeks after implantation were collected. Then, calculating mean LDH during 48 weeks after implantation, study population was divided into low and high mean LDH groups at the median value of mean LDH.

Results

The median value of mean LDH was 304 U/l. Compared with low LDH patients, though high LDH patients were more likely female and had smaller body surface area, there were no significant difference in pre-operative eGFR between the groups (66.0±23.7 vs. 70.2±25.7 ml/min/1.73m2, p=0.495). After 40 weeks after implantation, high LDH patients had significantly lower eGFR than low LDH patients (71.0±23.7 vs. 87.1±31.4 ml/min/1.73m2, p=0.024). In multivariate linear regression analysis, mean LDH [parameter estimate: −0.10 (95% CI: −0.17 to −0.04), p=0.003] and post-operative pulse pressure [parameter estimate: 0.71 (95% CI: 0.05 to 1.37), p=0.036] were significantly associated with eGFR change during 48 weeks after HeartMateII implantation.

Univariate and multivariate linear regression analysis for eGFR change Univariate parameter estimate 95% CI p value Multivariate parameter estimate 95% CI p value Bilirubin, mg/dl 9.97 3.82 to 16.13 0.002 6.55 −0.43 to 13.53 0.065 BNP, pg/ml 0.01 0.00 to 0.02 0.044 0.00 −0.01 to 0.01 0.528 Mean LDH during 4 to 48 weeks, U/l −0.11 −0.18 to −0.05 <0.001 −0.10 −0.17 to −0.04 0.003 Pre-operative right atrial pressure, mmHg 1.43 0.35 to 2.51 0.010 −0.06 −1.52 to 1.40 0.935 Post-operative pulse pressure, mmHg 0.77 0.03 to 1.52 0.042 0.71 0.05 to 1.37 0.036

Conclusions

High mean LDH and low pulse pressure were associated with a significant decrease in eGFR late after HeartMateII implantation. Subclinical persistent hemolysis may be associated with late renal function deterioration in CF-LVAD patients.

Terminal Ileac Ulcers Mimicked Post-transplantation Lymphoproliferative Disorder in a Heart Recipient Treated With Everolimus: A Case Report

Post-transplant lymphoproliferative disorder (PTLD) is a well-recognized and potentially fatal complication of cardiac transplantation that commonly involves the gastrointestinal tract. Herein, we report a case of life-threatening gastrointestinal bleeding from recurrent terminal ileac ulcers mimicking PTLD in a heart recipient treated with everolimus (EVL). A 40-year-old man underwent heart transplantation for dilated cardiomyopathy 3 years prior to the current admission and was treated with tacrolimus and EVL. He was admitted to a local hospital because of fever, abdominal pain, and diarrhea. His symptoms persisted and, 3 weeks later, hematochezia occurred; thus, he was transferred to our hospital. As computed tomography and ¹⁸F-fluorodeoxyglucose positron emission tomography showed bowel-wall thickening of the terminal ileum, gastrointestinal PTLD was initially suspected. However, although colonoscopy- performed after switching EVL to mycophenolate mofetil (MMF)-showed terminal ileac ulcers, the histologic examination revealed no findings corresponding to PTLD. As EVL may delay ulcer healing, MMF was maintained for 3 months. After repeated colonoscopy showed ulcer healing, MMF was switched back to EVL for cardiac allograft vasculopathy prevention. Three weeks later, he was emergently admitted to a local hospital for life-threatening gastrointestinal bleeding from a recurrent terminal ileal ulcer, which required hemostatic forceps hemostasis. As EVL is suspected to be associated with recurrent ileal ulcers, EVL was again switched back to MMF. The ileal ulcers resolved, without recurrence in 3 months of clinical follow-up. This case demonstrates that cases of life-threatening gastrointestinal bleeding from recurrent terminal ileac ulcers can mimic PTLD in a heart recipient treated with EVL.

Multiple sequence elements are involved in RNA 3' end formation in spleen necrosis virus

The function of the poly(A) signal in spleen necrosis virus (SNV) is dependent upon the distance between the cap site and the poly(A) site, while the function of the SV40 late poly(A) signal is independent of the distance. Deletions in the SNV poly(A) sequence do not alter the distance-dependent function. SNV/SV40 chimeric poly(A) signals show intermediate behavior between the SNV and SV40 poly(A) signals. These results indicate that multiple sequence elements are involved in the functions of either the SNV or SV40 poly(A) signals. This intermediate behavior is also observed with poly(A) signals from the mouse alpha-globin and herpes simplex virus thymidine kinase genes.

Conjugated Human Hemoglobin as a Physiological Oxygen Carrier - Pyridoxalated Hemoglobin Polyoxyethylene Conjugate (PHP)

Problems associated with specific physiological properties of Hb-based blood substitutes, such as a low P50, short plasma half-life and nephrotoxicity are still major issues to be addressed. Extensive investigations aimed at overcoming these problems have resulted in the preparation of pyridoxalated-hemoglobin-polyoxyethylene conjugate (PHP). PHP was developed from human hemoglobin by two major chemical modifications; pyridoxylation for the purpose of lowering the oxygen affinity (P50 of 19.5 ± 1.2 mmHg), and coupling with polyoxyethylene (POE) to increase its molecular weight (to approximately 90 kdaltons). The circulating half-life of PHP is about 40 hours in dogs. Toxicologicai and physiological studies including renal function assessments have demonstrated that PHP does not have untoward effects on major organ functions. Its efficacy in transporting oxygen has been shown in ET and intracoronary perfusion, and in in vitro studies with sickle cells. Studies to date suggest that PHP is a promising candidate as a physiological oxygen carrier. In this paper the properties of PHP, its safety and efficacy aspects, and its potential as a clinical oxygen carrier are reviewed based on studies conducted in the Author's laboratory.

Design Improvement of the Jellyfish Valve for Long-term Use in Artificial Hearts

In a previous communication, we reported a leaflet fracture in a Jellyfish valve that was incorporated into a blood pump, after a 312-day animal implant duration. Subsequent finite element analysis revealed that the fracture location was consistent with an area of maximum strain concentration. Therefore, the aim of this study was to improve the durability in the light of these findings. Based on the engineering analysis results, a new valve seat having a concentric ring of 0.5mm width, located at a radius of 7.0 mm, was designed and fabricated. Accelerated fatigue tests, conducted under the conditions recommended by ISO 5840, demonstrated that the durability of this new prototype was extended by a factor of 10, as compared to the original valve. Moreover, further finite element analysis indicated that the maximum equivalent elastic strain of the proposed new valve was reduced by 52.3% as compared to the original valve. Accordingly, it has been confirmed that the modified Jellyfish valve is suitable for use in long-term artificial hearts.

Significance of histologic pattern of carcinoma and sarcoma components on survival outcomes of uterine carcinosarcoma

BACKGROUND

To examine the effect of the histology of carcinoma and sarcoma components on survival outcome of uterine carcinosarcoma.

PATIENTS AND METHODS

A multicenter retrospective study was conducted to examine uterine carcinosarcoma cases that underwent primary surgical staging. Archived slides were examined and histologic patterns were grouped based on carcinoma (low-grade versus high-grade) and sarcoma (homologous versus heterologous) components, correlating to clinico-pathological demographics and outcomes.

RESULTS

Among 1192 cases identified, 906 cases were evaluated for histologic patterns (carcinoma/sarcoma) with high-grade/homologous (40.8%) being the most common type followed by high-grade/heterologous (30.9%), low-grade/homologous (18.0%), and low-grade/heterologous (10.3%). On multivariate analysis, high-grade/heterologous (5-year rate, 34.0%, P = 0.024) and high-grade/homologous (45.8%, P = 0.017) but not low-grade/heterologous (50.6%, P = 0.089) were independently associated with decreased progression-free survival (PFS) compared with low-grade/homologous (60.3%). In addition, older age, residual disease at surgery, large tumor, sarcoma dominance, deep myometrial invasion, lymphovascular space invasion, and advanced-stage disease were independently associated with decreased PFS (all, P < 0.01). Both postoperative chemotherapy (5-year rates, 48.6% versus 39.0%, P < 0.001) and radiotherapy (50.1% versus 44.1%, P = 0.007) were significantly associated with improved PFS in univariate analysis. However, on multivariate analysis, only postoperative chemotherapy remained an independent predictor for improved PFS [hazard ratio (HR) 0.34, 95% confidence interval (CI) 0.27-0.43, P < 0.001]. On univariate analysis, significant treatment benefits for PFS were seen with ifosfamide for low-grade carcinoma (82.0% versus 49.8%, P = 0.001), platinum for high-grade carcinoma (46.9% versus 32.4%, P = 0.034) and homologous sarcoma (53.1% versus 38.2%, P = 0.017), and anthracycline for heterologous sarcoma (66.2% versus 39.3%, P = 0.005). Conversely, platinum, taxane, and anthracycline for low-grade carcinoma, and anthracycline for homologous sarcoma had no effect on PFS compared with non-chemotherapy group (all, P > 0.05). On multivariate analysis, ifosfamide for low-grade/homologous (HR 0.21, 95% CI 0.07-0.63, P = 0.005), platinum for high-grade/homologous (HR 0.36, 95% CI 0.22-0.60, P < 0.001), and anthracycline for high-grade/heterologous (HR 0.30, 95% CI 0.14-0.62, P = 0.001) remained independent predictors for improved PFS. Analyses of 1096 metastatic sites showed that carcinoma components tended to spread lymphatically, while sarcoma components tended to spread loco-regionally (P < 0.001).

CONCLUSION

Characterization of histologic pattern provides valuable information in the management of uterine carcinosarcoma.

Effect of ADAMTS-13 on cerebrovascular microthrombosis and neuronal injury after experimental subarachnoid hemorrhage

BACKGROUND

Microthrombosis and reactive inflammation contribute to neuronal injury after subarachnoid hemorrhage (SAH). ADAMTS-13 cleaves von Willebrand factor multimers, and inhibits thrombus formation and, seemingly, inflammatory reactions.

OBJECTIVE

To investigate the effect of ADAMTS-13 in experimental SAH.

METHODS

A total of 100 male C57/BL6 mice were randomly assigned to four groups: sham (n = 15), SAH (n = 27), vehicle (n = 25), and ADAMTS-13 (n = 23; 100 μL per 10 g of body weight of 100 μg of ADAMTS-13 per 1 mL of 0.9% NaCl; 20 min after SAH). Neurologic performance was assessed on days 1 and 2 after SAH. Animals were killed on day 2. The amounts of subarachnoid blood, microthrombi, apoptosis and degenerative neurons were compared. The degree of neuronal inflammation and vasospasm was also compared. In five mice each (SAH and ADAMTS-13 groups), bleeding time was assessed 2 h after SAH.

RESULTS

Systemic administration of ADAMTS-13 achieved significant amelioration of microthrombosis and improvement in neurologic performance. ADAMTS-13 reduced the amount of apoptotic and degenerative neurons. A tendency for decreased neuronal inflammation was observed. ADAMTS-13 did not show any significant effect on vasospasm. The degree of systemic inflammation was not changed by ADAMTS-13 administration. ADAMTS-13 neither increased the amount of subarachnoid blood nor prolonged the bleeding time.

CONCLUSIONS

ADAMTS-13 may reduce neuronal injury after SAH by reducing microthrombosis formation and neuronal inflammation, thereby providing a new option for mitigating the severity of neuronal injury after SAH.

Three-step method for ultrasound-guided central vein catheterization

BACKGROUND

The long-axis view and in-plane needle approach (LAX-IP) for ultrasound-guided central vein catheterization is considered ideal because of the quality of real-time imaging. We describe a novel technique, using a step-by-step procedure, to overcome the pitfalls associated with the LAX-IP. This study was undertaken to demonstrate the clinical utility of this approach.

METHODS

All operators underwent training before participation in this study. One hundred patients were enrolled in this study and underwent central venous catheterization using this method. Using a portable ultrasound and vein catheterization kit, patients were appropriately positioned and a straight portion of the vein identified (Step 1). A needle guide was used (Step 2) and the vein imaged in real time in two directions (Step 3), to identify the true long axis and prevent damage to surrounding tissues.

RESULTS

The overall success rate for catheterization was 100% with a median of one puncture for each patient. All catheterizations were performed within three punctures. Problems with the first puncture included difficult insertion of the guide-wire due to coiling, difficult anterior wall puncture, less experience with the procedure, and other reasons. There were no complications associated with the procedure.

CONCLUSIONS

This three-step method is not dependent on an operator's ability to proceed based on spatial awareness, but rather depends on logic. This method can prevent difficulties associated with a two-dimensional ultrasound view, and may be a safer technique compared with others. Further clinical trials are needed to establish the safety of this technique.

The breath test system involving a novel tracer, ¹³C-uracil and Wagner-Nelson analysis: comparison with the gastric emptying scintigraphy

BACKGROUND/AIMS

In this pilot study, a new breath test system for gastric emptying study has been proposed.

METHODOLOGY

The system involves 13C-uracil as a novel tracer and the Wagner-Nelson method for analyzing breath data.

RESULTS

In three healthy volunteers, the new breath system allowed quantification of gastric emptying profiles as accurately as the scintigraphic technique.

CONCLUSIONS

Further validation studies with a lager sample size are needed.

Characterization of lactic acid bacteria-based probiotics as potential heavy metal sorbents

AIM

To isolate and characterize lactic acid bacteria (LAB) and determine whether they could potentially be used as heavy metal (cadmium and lead) absorbing probiotics.

METHODS AND RESULTS

The study used 53 environmental (mud and sludge) samples to isolate cadmium- and lead-resistant LAB, by following spared plate technique. A total of 255 cadmium- and lead-resistant LAB were isolated from these samples. The survival of 26 of the LAB was found after passing through sequential probiotic characterizations. These 26 probiotic LAB exhibited remarkable variations in their metal-resistant and metal-removal abilities. Of 26, seven (Cd54-2, Cd61-7, Cd69-12, Cd70-13, Pb82-8, Pb96-19 and Cd109-16) and four (Pb71-1, Pb73-2, Pb85-9 and Pb96-19) strains displayed relatively elevated cadmium- and lead-removal efficiencies from water, respectively, compare with that of the remaining strains. Strains Cd70-13 and Pb71-1 showed the highest cadmium (25%) and lead (59%) removal capacity from MRS (De Man, Rogosa and Sharpe) culture medium, respectively, amongst the selected strains and showed a good adhesive ability on fish mucus. A phylogenetic analysis of their 16S rDNA sequences revealed that the strains Cd70-13 and Pb71-1 belong to Lactobacillus reuteri.

CONCLUSION

Excellent probiotic, metal sorption and adhesive characteristics of newly identified Lact. reuteri strains Cd70-13 and Pb71-1 were isolated, which indicated their high potential abilities to survive in the intestinal milieu and to uptake the tested metals from the environment.

SIGNIFICANCE AND IMPACT OF THE STUDY

To our knowledge, this is the first study that has aimed to isolate, characterize and identify metal-resistant LAB strains that have potential to be a probiotic candidate for food and in vivo challenge studies in the intestinal milieu of fish for the uptake and control of heavy metal bioaccumulation.

Yokukansan, a traditional Japanese medicine, ameliorates memory disturbance and abnormal social interaction with anti-aggregation effect of cerebral amyloid β proteins in amyloid precursor protein transgenic mice

The deposition of amyloid β protein (Aβ) is a consistent pathological hallmark of Alzheimer's disease (AD) brains. Therefore, inhibition of Aβ aggregation in the brain is an attractive therapeutic and preventive strategy in the development of disease-modifying drugs for AD. An in vitro study demonstrated that yokukansan (YKS), a traditional Japanese medicine, inhibited Aβ aggregation in a concentration-dependent manner. An in vivo study demonstrated that YKS and Uncaria hook (UH), a constituent of YKS, prevented the accumulation of cerebral Aβ. YKS also improved the memory disturbance and abnormal social interaction such as increased aggressive behavior and decreased social behavior in amyloid precursor protein transgenic mice. These results suggest that YKS is likely to be a potent and novel therapeutic agent to prevent and/or treat AD, and that this may be attributed to UH.

Prognostic factors associated with a subchondral insufficiency fracture of the femoral head

OBJECTIVE

The aim of this study was to identify the risk factors associated with the prognosis of a subchondral insufficiency fracture of the femoral head (SIF).

METHODS

Between June 2002 and July 2009, 25 patients diagnosed with SIF were included in this study. Sequential radiographs were evaluated for the progression of collapse. Clinical profiles, including age, body mass index, follow-up period and Singh's index, were documented. The morphological characteristics of the low-intensity band on T(1) weighted MRI were also examined with regards to four factors: band length, band thickness, the length of the weight-bearing portion and the band length ratio (defined as the proportion of the band length to the weight-bearing portion of the femoral head in the slice through the femoral head centre).

RESULTS

Radiographically, a progression of collapse was observed in 15 of 25 (60.0%) patients. The band length in patients with progression of collapse [22.5 mm; 95% confidence interval (CI) 17.7, 27.3] was significantly larger than in patients without a progression of collapse (13.4 mm; 95% CI 7.6, 19.3; p<0.05). The band length ratio in patients with progression of collapse (59.8%; 95% CI 50.8, 68.9) was also significantly higher than in patients without a progression of collapse (40.9%; 95% CI 29.8, 52.0; p<0.05). No significant differences were present in the other values.

CONCLUSION

These results indicate that the band length and the band length ratio might be predictive for the progression of collapse in SIF.

Pocket epithelium in the pathological setting for HMGB1 release

High-mobility group box-1 (HMGB1) protein acts as a transcription factor in the nucleus and also as a pro-inflammatory cytokine when released into extracellular fluids. The presence of higher levels of HMGB1 is reported in the gingival crevicular fluid from periodontal patients. Since the proliferation of bacteria within the periodontal pocket is closely involved in the exacerbation of periodontal disease, it is hypothesized that the periodontal pocket causes the release of HMGB1. Immunohistochemical staining of inflamed gingiva revealed that HMGB1 is exclusively dislocated from the nucleus to the cytoplasm in the pocket epithelium, whereas it is mainly present in the nucleus in the gingival epithelium. Butyric acid, an extracellular metabolite from periodontopathic bacteria populating the periodontal pocket, induced the passive release of HMGB1 as a result of eliciting necrosis in the human gingival epithelial cell line. Thus, the periodontal epithelium may provide a unique pathological setting for HMGB1 release by bacterial insult.

[Impact of preoperative 64-row multislice computed tomography for congenital aortic stenosis; report of a case]

A 63-year-old woman was diagnosed as having severe aortic stenosis (AS) with 98 mmHg peak pressure gradient detected by echocardiography. Since, preoperative enhanced 64-row multislice computed tomography (MSCT) showed bicuspid aortic valve with only 2 sinuses of Valsalva, congenital aortic stenosis was suspected. The left and right coronary arteries originated from respective sinus of Valsalva, and severely thickened cusps of aortic valve were detected clearly by preoperative 64-row MSCT. Aortic valve replacement with a 21 mm ATS mechanical bileaflet prosthesis was performed without aortic annulus enlargement. The postoperative course was uneventful and postoperative 64-row MSCT indicated good performance of the ATS valve. Preoperative 64-row MSCT could be useful to detect complex aortic valve disease in detail. Moreover. 64-row MSCT might be a reliable tool to evaluate valvular heart disease.

Calibration system for pulse spectrophotometry using a double-layer pulsation flow-cell

We have studied noninvasive devices for measuring total hemoglobin and hemoglobin derivatives such as carboxyhemoglobin (COHb) and methemoglobin (MetHb). A calibration procedure needs to be developed to evaluate or calibrate these devices and pulse oximeters for clinical practice. However, people and animals are sometimes exposed to risk when they are used for calibration. In this paper, we propose a new in vitro calibration system for a pulse photometer. This system has a novel double-layer pulsation flow-cell that incorporates both venous and arterial blood flow. Using the calibration system, we are able to measure the in vitro pulsatile optical density ratio (Phivt). The measured Phivt agrees well with the in vivo pulsatile optical density ratio (Phivi). This system simulates an in vivo environment with high accuracy and enables safe calibration. Consequently, the calibration system is able to standardize the performance and accuracy of pulse photometry.

Cynomolgus monkey CYPs: a comparison with human CYPs

Characteristics of twelve cytochromes P450 (CYPs) from cynomolgus monkeys were compared with those of human CYPs that play an important role in drug metabolism. Eleven members of CYP1A, CYP2A, CYP2C, CYP2D, CYP2E, and CYP3A subfamilies from cynomolgus monkeys exhibited a high degree of homologies (more than 90%) in cDNA and amino acid sequences with corresponding human CYPs, and catalysed typical reactions of corresponding human CYPs. One member of the cynomolgus monkey CYP2C subfamily, CYP2C76, exhibited a lower homology (around 70%) in amino acid sequences with other cynomolgus monkey and human CYP2C subfamilies. CYP2C76 catalysed typical CYP2C substrates with low activities, and has not been found in humans. CYPs identified in cynomolgus monkeys were similar to CYP1A1, CYP1A2, CYP2A6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4, and CYP3A5 in humans. These results indicate that cynomolgus monkeys express CYPs similar to human CYPs that are important in drug metabolism.

Approach to predict the contribution of cytochrome P450 enzymes to drug metabolism in the early drug-discovery stage: The effect of the expression of cytochromeb5with recombinant P450 enzymes

In order to evaluate the potential adverse effects due to genetic polymorphism and/or inter-individual variation, it is necessary to calculate the cytochrome P450 (CYP) contribution to the metabolism of new drugs. In the current study, the in vitro intrinsic clearance (CL(int)) values of marker substrates and drugs were determined by measuring metabolite formation and substrate depletion, respectively. Recombinant CYP microsomes expressing CYP2C9, CYP2C19 and CYP3A4 with co-expressed cytochrome b(5) were used, but those expressing CYP1A2 and CYP2D6 did not have co-expressed cytochrome b(5). The following prediction methods were compared to determine the CL(int) value using data from recombinant CYP enzymes: (1) relative CYP enzyme content in human liver microsomes; (2) relative activity factor (RAF) estimated from the V(max) value; and (3) RAF estimated from the CL(int) value. Estimating RAF from CL(int) proved the most accurate prediction method among the three tested, and differences in the CYP3A4 marker reactions did not affect its accuracy. The substrate depletion method will be useful in the early drug-discovery stage when the main metabolite and/or metabolic pathway has not been identified. In addition, recombinant CYP microsomes co-expressed with cytochrome b(5) might be suitable for the prediction of the CL(int) value.