Interobserver agreement in endoscopic evaluation of reflux esophagitis using a modified Los Angeles classification incorporating grades N and M: a validation study in a cohort of Japanese endoscopists

The Los Angeles classification system is the most widely employed criteria associated with the greatest interobserver agreement among endoscopists. In Japan, the Los Angeles classification system has been modified (modified LA system) to include minimal changes as a distinct grade of reflux esophagitis, rather than as auxiliary findings. This adds a further grading M defined as minimal changes to the mucosa, such as erythema and/or whitish turbidity. The modified LA system has come to be used widely in Japan. However, there have been few reports to date that have evaluated the interobserver agreement in diagnosis when using the modified LA classification system incorporating these minimal changes as an additional grade. A total of 100 endoscopists from university hospitals and community hospitals, as well as private practices in the Osaka-Kobe area participated in the study. A total of 30 video clips of 30-40 seconds duration, mostly showing the esophagocardiac junction, were created and shown to 100 endoscopists using a video projector. The participating endoscopists completed a questionnaire regarding their clinical experience and rated the reflux esophagitis as shown in the video clips using the modified LA classification system. Agreement was assessed employing kappa (kappa) statistics for multiple raters. The kappa-value for all 91 endoscopists was 0.094, with a standard error of 0.002, indicating poor interobserver agreement. The endoscopists showed the best agreement on diagnosing grade A esophagitis (0.167), and the poorest agreement when diagnosing grade M esophagitis (0.033). The kappa-values for the diagnoses of grades N, M, and A esophagitis on identical video pairs were 0.275-0.315, with a standard error of 0.083-0.091, indicating fair intraobserver reproducibility among the endoscopists. The study results consistently indicate poor agreement regarding diagnoses as well as fair reproducibility of these diagnoses by endoscopists using the modified LA classification system, regardless of age, type of practice, past endoscopic experience, or current workload. However, grade M reflux esophagitis may not necessarily be irrelevant, as it may suggest an early form of reflux disease or an entirely new form of reflux esophagitis. Further research is required to elucidate the pathophysiological basis of minimal change esophagitis.

A preliminary study on driver's stress index using a new method based on differential skin temperature measurement

Prolonged periods of driving in monotonous situations may lower a driver's activation state as well as increasing their stress level due to the compulsion to maintain safe driving, which may result in an increased risk of a traffic accident. There is therefore an opportunity for technological assessment of driver physiological status to be applied in-car, hopefully reducing the incidence of potentially dangerous situations. As part of our long-term aim to develop such a system, we describe here the investigation of differential skin temperature measurement as a possible marker of a driver's stress level. 10 healthy male subjects were studied, under environment-controlled conditions, whilst being subjected to simulated monotonous travel at constant speed on a test-course. We acquired measurements of relevant physiological variables, including truncal and peripheral skin temperatures (T(s)), beat-by-beat blood pressure (BP), cardiac output (CO), total peripheral resistance (TPR), and normalized pulse volume (NPV) used as an indicator of local peripheral vascular tone. We then investigated the driver's reactivity in terms of cardiovascular haemodynamics and skin temperatures. We found that the simulated monotonous driving produced a gradual drop in peripheral T(s) following the driving stress, which, through interpretation of the TPR and NPV recordings, could be explained by peripheral sympathetic activation. On the other hand, the truncal T(s) was not influenced by the stress. These findings lead us to suggest that truncal-peripheral differential T(s) might be used as a possible index indicative of the driver's stress.

Hemodynamic responses during simulated automobile driving in a monotonous situation

Long hours of automobile driving under monotonous situations may cause the lowering of what we term a driver's activation state (DAS) or in other words the production of drowsiness, resulting in an increased risk of a traffic accident. There is therefore a need to create a newly advanced system focused on the DAS in-car, hopefully thus avoiding potentially dangerous situations. In order to develop such a system as a final goal, we have firstly set out to acquire such cardiovascular variables as beat-by-beat blood pressure (BP), RR interval from ECG and normalized pulse volume (NPV) used as a peripheral vascular tone of alpha-adrenergic sympathetic activity, during presentation to the driver of a screen movie simulating monotonous travel at constant speed on a test-course. Subsequently, we have investigated the reactivity in terms of the driver's cardiovascular hemodynamics. Through the successful monitoring of cardiovascular parameters during the movie presentation obtained in 11 healthy male subjects, the following results were obtained: The monotonous driving produces a statistically significant gradual rise in BP following drowsiness, which could be explained by enhancement of sympathetic activity using a time-frequency analysis of BP and RR. This finding strongly indicates that continuous driving in such monotonous situations can make a driver considerably stressful and thus may cause a gradual increase in BP, and that this gradual BP increase may be used as a possible index relevant to the DAS. This finding was also confirmed by the analysis of NPV, suggesting that the gradual increase in BP during the monotonous driving would be rather caused by a regulation of peripheral vasomotor constriction.

Feasibility study on driver's stress detection from differential skin temperature measurement

Prolonged monotonous driving may lower a driver's awareness level as well as increasing their stress level due to the compulsion to maintain safe driving, which may result in an increased risk of a traffic accident. There is therefore an opportunity for technological assessment of driver physiological status to be applied in-car, hopefully reducing the incidence of potentially dangerous situations. As part of our long-term aim to develop such a system, we describe here the investigation of differential skin temperature measurement as a possible marker of a driver's stress level. In this study, healthy male (n=18) & female (n=7) subjects were investigated under environment-controlled conditions, whilst being subjected to simulated monotonous travel at constant speed on a test-course. We acquired physiological variables, including facial skin temperature which consists of truncal and peripheral skin temperatures (Ts) using thermography, beat-by-beat blood pressure (BP), cardiac output (CO), total peripheral resistance (TPR), and normalized pulse volume (NPV) used as an indicator of local peripheral vascular tone. We then investigated the driver's reactivity in terms of skin temperatures with this background of cardiovascular haemodynamics. We found that the simulated monotonous driving produced a gradual drop in peripheral Ts following the driving stress, which, through interpretation of the TPR and NPV recordings, could be explained by peripheral sympathetic activation. On the other hand, the truncal Ts was not influenced by the stress. These findings lead us to suggest that truncal-peripheral differential Ts could be used as a possible index indicative of the driver's stress.

Radiation-induced reduction of osteoblast differentiation in C2C12 cells

Therapeutic radiation causes bone damage and may increase fracture risks in treatment for head-and-neck cancer and in pelvic irradiation. These properties can also be used for prevention of heterotopic ossification in hip arthroplasty. To evaluate the effects of ionizing radiation on osteoblast differentiation, C2C12 cells were directed into an osteogenic lineage by treatment with a combination of bone morphogenic protein 2 (BMP-2) (100 ng/ml) and heparin (30 mug/ml) 6 h after irradiation (2 and 4 Gy). Osteoblast differentiation was evaluated based on alkali phosphatase (ALP) activity and expression of mRNA encoding ALP and collagen type I. Ionizing radiation suppressed the growth of C2C12 cells and decreased expression of ALP and collagen type I mRNAs with concomitant reduction of the ALP activity. Although further studies are needed to elucidate the molecular mechanism, our findings suggest that ionizing radiation at therapeutic doses interferes with bone formation by reducing ALP activity and expression of mRNA encoding ALP and collagen type I.

Possible case of potentiation of the antiplatelet effect of cilostazol by grapefruit juice

We present a case of purpura associated with concomitant ingestion of cilostazol, aspirin and grapefruit juice. A 79-year-old man with atherosclerosis obliterans, taking cilostazol and aspirin, complained of purpura. Interview by a pharmacist revealed that he had been taking grapefruit juice for a month. His purpura disappeared upon cessation of grapefruit juice, although his medication was not altered. The most probable cause of his purpura is an increase in the blood level of cilostazol because of the inhibition of cilostazol metabolism by components of grapefruit juice. Aspirin may possibly have potentiated the risk of purpura. Grapefruit juice should be avoided in patients taking cilostazol, especially in patients being concomitantly treated with other anticoagulants.

Serodiagnostic potential of chemically synthesized glycosphingolipid antigens in an enzyme-linked immunosorbent assay for alveolar echinococcosis

In the serodiagnosis of alveolar echinococcosis, the detection of specific reactions against not only protein but also carbohydrate antigen is useful and both antigens supplement each other. Though recombinant protein antigens have recently advanced, the preparation of carbohydrate antigen still depends on extraction from crude antigens. In the latter case, it is not conventional to obtain carbohydrate antigen as a single component for examination and research. Therefore, chemically synthesized carbohydrate antigens were prepared for serodiagnosis by the enzyme-linked immunosorbent assay (ELISA). Four antigens with the structure of glycosphingolipids fromEchinococcus multiloculariswere examined and one antigen, Galβ1-6(Fucα1-3)Galβ1-6Galβ1-ceramide, was found to show significant serodiagnostic potential in differentiating alveolar from cystic echinococcosis.

Assessing the Effectiveness of Increased F<inf>I</inf>O<inf>2</inf>for Enhancing Driver's Activation State Using Simulated Monotonous Driving

Lowering of what we term a driver's Activation State (AS) during monotonous driving conditions may increase the risk of an accident. To develop an in-car environment that allows active driving - "Biofee dforward System" - we have investigated the effects of applying a stimulus of increased inspired oxygen fraction (F<inf>I</inf>O<inf>2</inf>) supply on a driver's AS, using simulated monotonous driving. We used our previously substantiated index of As derived from beat-by-beat blood pressure (BP) response following an electrical stimulus. We have made physiological measurements including BP and found that the increased F<inf>I</inf>O<inf>2</inf>stimulus is effective in enhancing the AS. This finding was also confirmed in terms of the autonomic activity balance as well as the lengthening in time for active, safer, driving.

Antacid interaction with new quinolones: dose regimen recommendations based on pharmacokinetic modeling of clinical data for ciprofloxacin, gatifloxacin and norfloxacin and metal cations

OBJECTIVE

New quinolones (NQs) are widely used to treat various infections. However, concomitant oral administration of metal cations may decrease absorption of NQs and consequently decrease their blood concentration and pharmacological effect. A convenient approach to avoid this interaction is to separate the dosages by a certain interval. In this study, we aimed to develop a novel pharmacokinetic model to describe NQs-metal cation interactions in order to estimate the optimal dosing interval.

METHODS

Plasma concentration-time profiles of NQs after administration without or with metal cations at various dosing intervals were collected from the literature and analyzed with a pharmacokinetic model incorporating the formation ofNQs-metal cations complex. The model was fitted to the reported time profiles ofciprofloxacin (CPFX) plasma concentration after concomitant administration with aluminum hydroxide/magnesium hydroxide antacid (Al/Mg antacid; Maalox, Maalox70) at various dosing intervals to obtain the pharmacokinetic parameters of CPFX. Model analysis was also carried out for gatifloxacin (GFLX) and norfloxacin (NFLX).

RESULTS

The developed model could adequately explain the interactions in all the combinations investigated. The model predicted, in the cases of usual doses of CPFX with Maalox, GFLX with Maalox70 and NFLX with sucralfate, that the NQ should be administered 4.5, 4.5 and 3.5 hours after, or 1, 1 and 0.5 hours before the administration of metal cations, respectively, to ensure 90% of control absorption.

CONCLUSIONS

The developed model can adequately describe the extent of interaction between NQs and metal cations, and should be clinically useful to design dosage regimens to circumvent the interaction.

Preparation of prefabricated vascularized bone graft with neoangiogenesis by combination of autologous tissue and biodegradable materials

Prefabricated vascularized bone grafts have previously been prepared by combining an autologous vessel bundle with auto-particulate cancellous bone and marrow (PCBM) and a biodegradable membrane. Only small quantities of low-density vascularized bone tissue have been formed using this method. The authors of the present study combined beta-tricalcium phosphate (beta-TCP), a biodegradable ceramic, with a prefabricated vascularized bone graft to augment osteogenesis. A saphenous vessel bundle from a rat was wrapped in a biodegradable membrane. Then, autologous PCBM was mixed with beta-TCP granules and packed into the rolled membrane. In the control group, beta-TCP was omitted. Bone formation was histologically assessed 6 and 9 weeks after implantation. The volume of newly formed bone tissue in the rolled membrane was greater in the presence of beta-TCP granules than in the control. Microvessels had formed throughout the new bone tissue. When a prefabricated vascularized bone graft was onlay-grafted to the femur of the same rat, the prefabricated vascularized bone graft directly fused to the cortical surface of the femur, with no intervening fibrous tissue. These findings suggest that beta-TCP in combination with PCBM enhances the volume and density of bone tissue in prefabricated vascularized bone grafts.

Dosage adjustment of quinolone antibiotics and angiotensin-converting enzyme inhibitors in patients with renal dysfunction

The aim of this study was to verify an approach for calculating pharmacokinetic parameters suitable for adjusting dosage regimens in patients with renal dysfunction. We carried out a retrospective analysis of the pharmacokinetic profiles of 12 new quinolone antibiotics and 11 angiotensin-converting enzyme inhibitors (ACEIs) in patients with normal and impaired renal function to obtain the renal excretion ratio (R(renal)) of each drug. We demonstrated that the pharmacokinetics of each drug in a patient with renal dysfunction can be adequately estimated using the R(renaI) value of each drug together with the creatinine clearance as an index of the individual's renal function. Using the R(renaI) value obtained, we could successfully simulate pharmacokinetic profiles of the drugs in publications other than that used to obtain the R(renal) values. On the other hand, age-related changes in the pharmacokinetics of new quinolone antibiotics are not always adequately predicted using the R(renal) value compared to using creatinine clearance alone as an index, and the reasons for this are not fully understood. These results demonstrate that dosage regimens of quinolone antibiotics and ACEIs in patients with renal dysfunction can be adequately optimized using the R(renal) value for each drug using the present approach.

A new camera trocar for gasless endoscopic thyroid surgery

A commercially available camera trocar diminishes the working space because of its high profile and is not proof against blood stain. The authors designed a new camera trocar for gasless endoscopic thyroid surgery. The new trocar consists of a shaft for a 5-mm endoscope as well as a disc 18 mm in diameter and 2 mm thick. The trocar is inserted from an adjacent 3-cm working port, pushed out to an incision for a 5-mm endoscope, and placed with the shaft up and the disc down. Because of its disc, the trocar is designed to be proof against blood stain and to maintain more working space. The newly designed trocar might be very useful for gasless endoscopic thyroid surgery as well as other gasless surgical procedures.

Interactions between clarithromycin and digoxin in patients with end-stage renal disease

OBJECTIVE

To report a significant increase in the serum levels of digoxin associated with the use of clarithromycin in six patients undergoing renal replacement therapy.

CASE SUMMARY

All six patients were males with end-stage renal disease and in need of renal replacement therapy. Four patients were anuric. The mean age was 78.8 +/- 5.8 (66-83) years. All patients except one, who was treated by hemofiltration, were treated by hemodialysis. All patients except one, who had been treated with metildigoxin (0.35 mg/week), were also taking digoxin (0.375 mg/week). Clarithromycin was administered at a dose of 200-400 mg/day for the treatment of bronchitis in all patients. The concomitant administration of clarithromycin increased serum digoxin levels from 1.8-4.0-fold in all cases. In two of six cases, a high probability of digoxin intoxication and suspicion of digoxin intoxication was evident. In three of six cases, serum digoxin levels increased within 12 days after the co-administration of clarithromycin, while in the other three cases, serum digoxin levels were increased 53-190 days after the administration of clarithromycin.

CONCLUSION

The simultaneous administration of clarithromycin caused an increase in digoxin levels in six patients undergoing renal replacement therapy. The increase in the serum digoxin can be attributed to the inhibition of P-glycoprotein in the intestine and/or bile capillary rather than the kidney by clarithromycin since renal function was dramatically impaired, and four of the patients were anuric. The issue of why serum digoxin levels were increased so late in three patients undergoing renal replacement is unclear. However, this interaction seemed to be clinically significant even in ESRD patients, whose renal function was highly impaired. The simultaneous use of digoxin and clarithromycin should be avoided even in patients undergoing renal replacement therapy whose renal function is impaired, since digoxin levels may increase unexpectedly.

Association between neuroleptic drug-induced extrapyramidal symptoms and dopamine D2-receptor polymorphisms in Japanese schizophrenic patients

The aim of the present study is to examine the relationship between dopamine D2-receptor gene (DRD2) polymorphisms (Taq1A, Taq1B, -141C Ins/Del) and the risk of extrapyramidal adverse effects (EPS), assessed according to the Drug-Induced Extra-Pyramidal Symptoms Scale (DIEPSS), or the maintenance dose of antipsychotics in schizophrenic patients. The DIEPSS score was significantly higher in patients bearing the -141C Del allele than in those without it. Taq1A and Taq1B restriction fragment length polymorphisms (RFLPs) did not significantly affect the DIEPSS score. On the other hand, maintenance doses of neuroleptics and antiparkinsonian drugs were significantly higher in patients with the B1 allele of Taq1B RFLP than in those without it, while the Taq1A RFLP and -141C Ins/Del polymorphisms were not significantly related to the maintenance doses. In conclusion, the risk of EPS may be increased in patients with the -141C Del allele of the DRD2 gene. In these patients, antipsychotics should be administered with caution.

Effect of hematocrit on pharmacokinetics of tacrolimus in adult living donor liver transplant recipients

OBJECTIVE

Plasma drug concentrations are generally considered to reflect efficacy and pharmacokinetics more directly than those in whole blood. However, whole blood has been selected as the matrix to monitor concentrations of tacrolimus (FK506), because it is difficult to accurately measure plasma FK506 concentrations. Because FK506 highly and saturably binds in blood cells, a change in hematocrit value (Hct) may affect FK506 pharmacokinetics. Therefore, we investigated effects of Hct on FK506 pharmacokinetics.

METHODS

First, we analyzed data on FK506 distribution among human blood cells in vitro. Briefly, we employed an equation, which describes saturable binding of FK506 to blood cells, and simulated plasma FK506 concentrations and clearances using the above equation with respect to a variable Hct. Subsequently, we retrospectively analyzed dosages and whole blood FK506 concentrations to predict plasma FK506 concentrations in living donor transplant recipients.

RESULTS

In the simulation study, the Hct changed plasma FK506 concentrations and clearances based in whole blood. In living donor liver transplant recipients, whole blood FK506 concentrations were maintained within a therapeutic range, while the Hct varied after transplantation. The correlation of Hct with the ratio of dose/trough concentrations of FK506 (D/C) in plasma (D/Cp) (R = -0.23, n = 343) was weaker than that for D/C in whole blood (D/CWB) (R = -0.53, n = 343).

CONCLUSION

Hct may be an important factor affecting the pharmacokinetics of FK506 in living donor liver transplantation recipients. It may be necessary to take Hct into consideration in the FK506 dosing regimen, especially when the Hct is low.

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

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

Treatment of gastric hemorrhage by pulverized omeprazole and antacid – concomitant administration via a nasogastric tube

Gastroesophageal reflux (GER) is a common episode in pediatric patients with severe motor and intellectual disabilities (SMID) and occasionally leads to a severe clinical state accompanied with nausea, hematemesis, melena, wheezing, pneumonia, anemia and/or failure to thrive. We report here a case of a 14-year-old male with Lennox syndrome who had been treated with a histamine H2 blocker intravenously or via a nasogastric tube for repeated gastric hemorrhage due to severe GER. Since his gastric hemorrhage became resistant to the H2 blocker, we decided to replace it with a proton pump inhibitor (PPI). Although lansoprazole can be decapsulated for administration via a nasogastric tube, it tends to block fine tubes. The acid-sensitive drug omeprazole, another oral PPI, is commercially available as enteric-coated tablets. Therefore, we pulverized the tablets and administered omeprazole, mixed with a small amount of antacid, via a nasogastric tube. The patient's gastric hemorrhage was dramatically improved. Thus, administration of pulverized omeprazole concomitantly with antacid via a fine nasogastric tube may provide a novel approach for the treatment of chronic GER in pediatric patients with SMID.

Basal Membrane Localization of MRP1 in Human Placental Trophoblast

The placental trophoblast is considered to act as a barrier between mother and fetus, mediating the exchange of various materials across the placenta. ATP-binding cassette (ABC) transporters such as P-glycoprotein (P-gp) and multidrug-resistance protein (MRP) are expressed in the placenta and function as efflux transport systems for xenobiotics. In the present study, we aimed to determine the localization of MRP1 in the human placenta in comparison with that of P-gp. Western blotting analysis with human placental membrane vesicles indicated that P-gp and MRP1 are localized on the brush-border membranes and basal membranes, respectively. Immunohistochemical analysis with human normal full-term placenta showed that anti-P-gp monoclonal antibody F4 stained the brush-border side of the trophoblast cells, whereas anti-MRP1 monoclonal antibody MRPr1 stained the basal side. These results confirm that P-gp and MRP1 are located on the brush-border membranes and basal membranes, respectively, of human full-term placental trophoblast. MRP1 was also detected on the abluminal side of blood vessels in the villi. Accordingly, MRP1 may play a role distinct from that of P-gp, which is considered to restrict the influx of xenobiotics into the fetus.