Development of blood collection tubes for glucose measurement using adenosine 3-phosphate and sodium fluoride as glycolytic inhibitors

BACKGROUND

Blood collection tubes with sodium fluoride (NaF) added as a glycolytic inhibitor are widely used for glucose measurement. However, the glycolytic inhibitory effects of NaF are insufficient, and decreases in glucose levels over time after blood collection have become a problem.

METHODS

Blood from a volunteer collected using an NaF tube was used to compare the glycolysis inhibitory abilities of ATP and ADP. Blood samples from 10 volunteers were collected in NaF tubes and NaF tubes with added ATP (NaF-ATP tubes). The stability of glucose and haemoglobin (Hb)A1c after whole-blood storage from immediately after blood collection to 24 h later was compared.

RESULTS

ATP and ADP had similar inhibitory effects on glycolysis, but ATP was selected as an additive for blood collection tubes because ADP was more haemolytic than ATP. We verified the ability of NaF blood collection tubes supplemented with ATP to inhibit glycolysis. Mean (± standard deviation) glucose levels (n=10) after storage for 24 h after blood collection decreased to -9.0 ± 2.7 mg/dL (-0.50 ± 0.15 mmol/L) in conventional NaF tubes. NaF-ATP(20) tubes with 20 mg (0.036 mmol) ATP added showed a reduced decrease, with a mean of -5.8 ± 2.9 mg/dL (-0.32 ± 0.16 mmol/L). NaF-ATP tubes also had no effect on HbA1c measurement.

CONCLUSION

This study reports on a blood collection tube that enables the measurement of glucose and HbA1c. Based on the results of validation, we conclude that NaF-ATP tubes can reduce decreases in glucose over time in stored whole blood compared to conventional NaF tubes.

Dose-dependent artificial prolongation of prothrombin time by interaction between daptomycin and test reagents in patients receiving warfarin: a prospective in vivo clinical study

Background

Daptomycin has been reported to cause artificial prolongation of prothrombin time (PT) by interacting with some test reagents of PT. This prolongation was particularly prominent with high concentrations of daptomycin in vitro. However, whether this prolongation is important in clinical settings and the optimal timing to assess PT remain unclear.

Methods

A prospective clinical study was conducted with patients who received daptomycin for confirmed or suspected drug-resistant, gram-positive bacterial infection at a university hospital in Japan. PT at the peak and trough of daptomycin was tested using nine PT reagents. Linear regression analyses were used to examine the difference in daptomycin concentration and the relative change of PT-international normalized ratios (PT-INR).

Results

Thirty-five patients received daptomycin (6 mg/kg). The mean ± standard deviation of the trough and peak concentrations of daptomycin were 13.5 ± 6.3 and 55.1 ± 16.9 μg/mL, respectively. Twelve patients (34%) received warfarin. With five PT reagents, a significant proportion of participants experienced prolongation of PT-INR at the daptomycin peak concentration compared to the PT-INR at the trough, although the mean relative change was less than 10%. None of the participants clinically showed any signs of bleeding. A linear, dose-dependent prolongation of PT was observed for one reagent [unadjusted coefficient β 3.1 × 10⁻³/μg/mL; 95% confidence interval (CI) 2.3 × 10⁻⁵–6.3 × 10⁻³; p = 0.048]. When patients were stratified based on warfarin use, this significant linear relationship was observed in warfarin users for two PT reagents (adjusted coefficient β, 6.4 × 10⁻³/μg/mL; 95% CI 3.5 × 10⁻³–9.3 × 10⁻³; p < 0.001; and adjusted coefficient β, 8.3 × 10⁻³/μg/mL; 95% CI 4.4 × 10⁻³–1.2 × 10⁻²; p < 0.001). In non-warfarin users, this linear relationship was not observed for any PT reagents.

Conclusions

We found that a higher concentration of daptomycin could lead to artificial prolongation of PT-INR by interacting with some PT reagents. This change may not be clinically negligible, especially in warfarin users receiving a high dose of daptomycin. It may be better to measure PT at the trough rather than at the peak daptomycin concentration.

Inverse correlations between serum ADAMTS13 levels and systolic blood pressure, pulse pressure, and serum C-reactive protein levels observed at a general health examination in a Japanese population: a cross-sectional study

BACKGROUND

Although a defect in ADAMTS13 activity is known to cause platelet thrombosis resulting in thrombotic thrombocytopenic purpura (TTP), recent evidence has revealed that low plasma ADAMTS13 concentrations may increase the risk of ischemic vascular diseases. Furthermore, reduced plasma ADAMTS13 activity has been reported in acute systemic inflammation or sepsis. These findings prompted us to examine whether ADAMTS13 may play a role in more diverse diseases, not limited to TTP.

METHODS

A cross-sectional study was conducted to examine ADAMTS13 concentrations in blood samples from 432 subjects who had undergone a general health examination.

RESULTS

Serum ADAMTS 13 concentrations were lower in men than in women and in older age, as previously reported. Of note, the serum ADAMTS13 concentration was significantly and inversely correlated with the systolic blood pressure, pulse pressure, and serum C reactive protein concentration in both men and women and with the serum γ-glutamyltransferase concentration in men only. In 88 subjects, who underwent a carotid artery evaluation, serum ADAMTS13 concentrations were significantly lower in the subjects with a thicker carotid intima-media.

CONCLUSIONS

ADAMTS13 may play a role in not only TTP, but also inflammation, oxidative stress, and atherosclerosis. The potentially diverse clinical significance of ADAMTS13 should be prospectively elucidated in a larger cohort.

Prediction of hepatocellular carcinoma development by plasma ADAMTS13 in chronic hepatitis B and C

BACKGROUND

Chronic liver injury evokes a wound healing response, promoting fibrosis and finally hepatocellular carcinoma (HCC), in which hepatic stellate cells play an important role. Although a blood marker of hepatic stellate cells is not known, those cells importantly contribute to the regulation of plasma a disintegrin-like and metalloproteinase with thrombospondin type-1 motifs 13 (ADAMTS13) activity, a defect of which causes thrombotic thrombocytopenic purpura.

METHODS

Plasma ADAMTS13 was evaluated in chronic hepatitis B or C patients with or without HCC.

RESULTS

Plasma ADAMTS13 activity significantly correlated with serum aspartate aminotransferase and alanine aminotransferase, liver stiffness value, and aspartate aminotransferase-to-platelet ratio index, irrespective of the presence of HCC, suggesting that it may reflect hepatocellular damage and subsequent wound healing and fibrosis as a result of hepatic stellate cell action. During the three-year follow-up period for patients without HCC, it developed in 10 among 81 patients. Plasma ADAMTS13 activity was significantly higher in patients with HCC development than in those without and was a significant risk for HCC development by univariate and multivariate analyses. Furthermore, during the one-year follow-up period for patients with HCC treated with radiofrequency ablation, HCC recurred in 55 among 107 patients. Plasma ADAMTS13 activity or antigen level was significantly higher in patients with HCC recurrence than in those without and was retained as a significant risk for HCC recurrence by multivariate analysis.

CONCLUSIONS

Higher plasma ADAMTS13 activity and antigen level was a risk of HCC development in chronic liver disease.

IMPACT

Plasma ADAMTS13 as a potential marker of hepatic stellate cells may be useful in the prediction of hepatocarcinogenesis.

Non-Michaelis–Menten Type Hepatic Uptake of Liposomes in the Rat

The objective of this study was to verify the methodology for measuring uptake clearance of liposomes and to characterize kinetically the saturable hepatic uptake of liposomes through phagocytosis. The correction of vascular space was important in the evaluationof hepatic uptake. The efflux of liposomes from liver was shown to be negligible, by a repeated dose study, and thus, hepatic clearance can be obtained by the hepatic uptake divided by the area under the blood concentration-time curve (AUC). The determinant parameter which describes the saturability of uptake clearance of liposomes, independent of infusion rate, was investigated, using the data of an in-vivo constant infusion study, where infusion rate-dependent saturable hepatic clearance was observed. The mean blood concentration failed to obtain an infusion rate-independent function. On the other hand, the AUC could explain the saturability of hepatic clearance for every infusion rate by a unique relationship. The hepatic uptake amount could also explain this saturability, independent of infusion rate. These kinetic characteristics are inconsistent with Michaelis–Menten type kinetics, therefore a new model is required to describe the saturable hepatic clearance in the disposition of liposomes.

Specific increase in serum autotaxin activity in patients with pancreatic cancer

OBJECTIVES

To evaluate the potential clinical significance of serum autotaxin (ATX) level in patients with cancers of the digestive system.

DESIGN AND METHODS

Serum ATX activity was measured as the lysophospholipase D activity in patients with cancer of the esophagus (n=8), stomach (n=18), colorectum (n=21), biliary tract (n=19), or pancreas (n=103) and in patients with benign pancreatic diseases (n=73).

RESULTS

Among patients with various cancers of digestive system, increased serum ATX activity was predominantly observed among pancreatic cancer patients. Serum ATX activity was not increased in patients with chronic pancreatitis or pancreatic cysts. In the diagnosis of pancreatic cancer, the area under the receiver operating curve for serum ATX activity was 0.541 (95% CI, 0.435-0.648) for men and 0.772 (95% CI, 0.659-0.885) for women. No significant correlation was observed between serum ATX activity and CEA, CA19-9 or Dupan2 levels.

CONCLUSION

Serum ATX activity may be useful for identifying pancreatic cancer when used together with other serum markers of pancreatic cancer.

Autotaxin as a novel serum marker of liver fibrosis

BACKGROUND

The clinical significance of autotaxin (ATX), a key enzyme for the production of the bioactive lysophospholipid lysophosphatidic acid remains unknown. Serum ATX enzymatic activity reportedly increases in parallel with liver fibrosis and exhibits a gender difference.

METHODS

Serum ATX antigen level, measured easier than the activity, was evaluated as a marker of liver fibrosis in 2 cohorts of chronic liver disease caused by hepatitis C virus.

RESULTS

In the first cohort, serum ATX level correlated significantly with liver fibrosis stage and was the best parameter for prediction of cirrhosis with an area under the receiver operating characteristic curve (AUROC) of 0.756 in male and 0.760 in female, when compared with serum hyaluronic acid and aminotransferase-to-platelet ratio index, an established marker of liver fibrosis. In another cohort, serum ATX level correlated significantly with liver stiffness, a novel reliable marker of liver fibrosis, being the second-best parameter in male (AUROC, 0.799) and in female (AUROC, 0.876) for prediction of significant fibrosis, and the best parameter in male (AUROC, 0.863) and the third-best parameter in female (AUROC, 0.872) for prediction of cirrhosis, both of which were judged by liver stiffness.

CONCLUSIONS

Serum ATX level may be a novel marker of liver fibrosis.

Plasma concentration of bioactive lipid mediator sphingosine 1-phosphate is reduced in patients with chronic hepatitis C

BACKGROUND

Bioactive lipid mediator S1P has been suggested to play pathophysiological roles in various fields of clinical science as a circulating paracrine mediator. We previously established a reliable method of measuring plasma S1P concentration, and reported that the one in healthy subjects has a gender difference and a correlation with red blood cell (RBC)-parameters, however, the reports of S1P measurements in the blood in patients with a specific disease have been scarce. Because our previous evidence suggests that S1P is involved in liver pathophysiology, we examined plasma S1P concentration in chronic hepatitis C patients.

METHODS

S1P assay was performed using a high-performance liquid chromatography system.

RESULTS

Plasma S1P concentrations were reduced in chronic hepatitis C patients compared with in healthy subjects with the same hemoglobin concentration, irrespective of gender. Among the blood parameters, serum hyaluronic acid concentration, a surrogate marker for liver fibrosis, was most closely and inversely correlated with plasma S1P concentration. Furthermore, plasma S1P concentration decreased throughout the progression of carbon tetrachloride-induced liver fibrosis in rats.

CONCLUSIONS

Plasma S1P concentration was reduced in chronic hepatitis C patients, and liver fibrosis might be involved, at least in part, in the mechanism responsible for this reduction.

Increased production of ADAMTS13 in hepatic stellate cells contributes to enhanced plasma ADAMTS13 activity in rat models of cholestasis and steatohepatitis

Although hepatic stellate cells, endothelial cells, glomerular podocytes and plateles were reported to be a source of ADAMTS13, it is not clarified which source is involved in the regulation of plasma ADAMTS13 activity. It was demonstrated previously that selective hepatic stellate cell damage in rats caused decreased plasma ADAMTS13 activity. To further elucidate the potential contribution of hepatic stellate cells to the regulation of plasma ADAMTS13 activity, this study examined plasma ADAMTS13 activity when hepatic stellate cells proliferate during the process of liver fibrosis by employing rat models of liver fibrosis due to cholestasis, bile duct ligation, and steatohepatitis, a choline-deficient L-amino acid-defined-diet. ADAMTS13 expression was increased with co-localisation with smooth muscle alpha-actin, a marker of hepatic stellate cells, in bile duct-ligated livers up to four weeks, in which a close correlation between ADAMTS13 and smooth muscle alpha-actin mRNA expressions was determined. Plasma ADAMTS13 activity, measured by a sandwich ELISA involving a specific substrate to ADAMTS13, was increased in bile duct-ligated rats with a significant correlation with ADAMTS13 mRNA expression levels in the liver. Furthermore, ADAMTS13 mRNA expression was increased with enhanced mRNA expression in smooth muscle alpha-actin in the livers of rats fed a choline-deficient L-amino acid-defined-diet for 16 weeks, in which increased plasma ADAMTS13 activity was determined. Thus, increased plasma ADAMTS13 activity in cholestasis and steatohepatitis in rats may be due, at least in part, to enhanced ADAMTS13 production in the liver, suggesting a significant role of hepatic stellate cells in the regulation of plasma ADAMTS13 activity.

[Significance of serum autotaxin activity in gastrointestinal disease]

Autotaxin (ATX), discovered in human melanoma cells, has been gaining attention because it could be involved in cancer invasion and metastasis as an autocrine motility factor. Recent evidence has indicated that ATX is a key enzyme in the synthesis of lysophosphatidic acid, a lipid mediator with a wide range of biological actions including the stimulation of proliferation and contraction in hepatic stellate cells, a pivotal player in hepatic fibrosis. Serum ATX activity was found to be enhanced in relation to hepatic fibrosis in chronic liver disease due to hepatitis virus C infection, and the possible contribution of ATX to the pathogenesis of hepatic fibrosis should be further clarified. Although an enhanced activity of serum ATX was noted in patients with hepatocellular carcinoma, this may be due to hepatic fibrosis from which hepatocellular carcinoma often arises. It is worth further evaluating whether serum ATX activity is significantly enhanced in patients with cancers of the digestive system other than hepatocellular carcinoma.

Sphingosine 1-phosphate regulates regeneration and fibrosis after liver injury via sphingosine 1-phosphate receptor 2

Sphingosine 1-phosphate (S1P), a bioactive lipid mediator, stimulates proliferation and contractility in hepatic stellate cells, the principal matrix-producing cells in the liver, and inhibits proliferation via S1P receptor 2 (S1P(2)) in hepatocytes in rats in vitro. A potential role of S1P and S1P(2) in liver regeneration and fibrosis was examined in S1P(2)-deficient mice. Nuclear 5-bromo-2'-deoxy-uridine labeling, proliferating cell nuclear antigen (PCNA) staining in hepatocytes, and the ratio of liver weight to body weight were enhanced at 48 h in S1P(2)-deficient mice after a single carbon tetrachloride (CCl(4)) injection. After dimethylnitrosamine (DMN) administration with a lethal dose, PCNA staining in hepatocytes was enhanced at 48 h and survival rate was higher in S1P(2)-deficient mice. Serum aminotransferase level was unaltered in those mice compared with wild-type mice in both CCl(4)- and DMN-induced liver injury, suggesting that S1P(2) inactivation accelerated regeneration not as a response to enhanced liver damage. After chronic CCl(4) administration, fibrosis was less apparent, with reduced expression of smooth-muscle alpha-actin-positive cells in the livers of S1P(2)-deficient mice, suggesting that S1P(2) inactivation ameliorated CCl(4)-induced fibrosis due to the decreased accumulation of hepatic stellate cells. Thus, S1P plays a significant role in regeneration and fibrosis after liver injury via S1P(2).

Rho-kinase inhibitor prevents hepatocyte damage in acute liver injury induced by carbon tetrachloride in rats

A protective effect of Rho-kinase inhibitor on various organ injuries is gaining attention. Regarding liver injury, Rho-kinase inhibitor is reported to prevent carbon tetrachloride (CCl4)- or dimethylnitrosamine-induced liver fibrosis and hepatic ischemia-reperfusion injury in rats. Because Rho-kinase inhibitor not only improved liver fibrosis but also reduced serum alanine aminotransferase (ALT) level in CCl4-induced liver fibrosis, we wondered whether Rho-kinase inhibitor might exert a direct hepatocyte-protective effect. We examined this possibility in acute CCl4 intoxication in rats. Rho-kinase inhibitor, HA-1077, reduced serum alanine ALT level in rats with acute liver injury induced by CCl4 with the improvement of histological damage and the reduction of the number of apoptotic cells. In cultured rat hepatocytes in serum-free condition, HA-1077 reduced apoptosis evaluated by quantitative determination of cytoplasmic histone-associated DNA oligonucleosome fragments with the reduction of caspase-3 activity and the enhancement of Bcl-2 expression. HA-1077 stimulated phosphorylation of Akt, and wortmannin, an inhibitor of phosphatidylinositol 3-kinase (PI3-kinase)/Akt pathway, abrogated the reduction of hepatocyte apoptosis by HA-1077 in vitro. Furthermore, wortmannin abrogated the reduction of serum ALT level by HA-1077 in rats with acute liver injury induced by CCl4, suggesting that the activation of PI3-kinase/Akt pathway may be involved in the hepatocyte-protective effect by Rho-kinase inhibitor in vivo. In conclusion, Rho-kinase inhibitor prevented hepatocyte damage in acute liver injury induced by CCl4 in rats and merits consideration as a hepatocyte-protective agent in liver injury, considering its direct antiapoptotic effect on hepatocytes in vitro.

Plasma lysophosphatidic acid level and serum autotaxin activity are increased in liver injury in rats in relation to its severity

Lysophosphatidic acid (LPA) is a lipid mediator with multiple biological actions. We have reported that LPA stimulates hepatic stellate cell proliferation and inhibits DNA synthesis in hepatocytes, suggesting that LPA might play some role in the liver. We have found that plasma LPA level and serum autotaxin (ATX) activity were increased in patients with chronic hepatitis C. However, the clinical significance of LPA and its synthetic enzyme, autotaxin (ATX), is still unclear. To determine whether the increase of plasma LPA level and serum ATX activity might be found generally in liver injury, we examined the possible modulation of them in the blood in rats with various liver injuries. Plasma LPA level and serum ATX activity were increased in carbon tetrachloride-induced liver fibrosis correlatively with fibrosis grade, in dimethylnitrosamine-induced acute liver injury correlatively with serum alanine aminotransferase level or in 70% hepatectomy as early as 3 h after the operation. Plasma LPA level was correlated with serum ATX activity in rats with chronic and acute liver injury. ATX mRNA in the liver was not altered in carbon tetrachloride-induced liver fibrosis. Plasma LPA level and serum ATX activity are increased in various liver injuries in relation to their severity. Whether increased ATX and LPA in the blood in liver injury is simply a result or also a cause of the injury should be further clarified.

Both plasma lysophosphatidic acid and serum autotaxin levels are increased in chronic hepatitis C

OBJECTIVES

Recent accumulating evidence indicates that lysophosphatidic acid (LPA) is a lipid mediator, abundantly present in blood, with a wide range of biologic actions including the regulation of proliferation and contraction in liver cells. Although it is speculated that LPA might play a role in pathophysiologic processes in vivo, not only its role but also even a possible alteration in its blood concentration under specific diseases is essentially unknown. Autotaxin (ATX), originally purified as an autocrine motility factor for melanoma cells, was revealed to be a key enzyme in LPA synthesis. We determined LPA and ATX levels in the blood of patients with liver disease.

METHODS

ATX activity was measured by determining choline with the substrate of lysophosphatidylcholine, and the LPA level by an enzymatic cycling method in 41 patients with chronic hepatitis C.

RESULTS

The serum ATX activity and plasma LPA level were significantly increased in patients, and were correlated positively with serum hyaluronic acid, and negatively with platelets, albumin, and prothrombin time. The plasma LPA level was strongly correlated with serum ATX activity. There were significant correlations between the histologic stage of fibrosis and both the serum ATX activity and plasma LPA level.

CONCLUSIONS

The serum ATX activity and plasma LPA level are increased in chronic hepatitis C in association with liver fibrosis. Our study may provide the first evidence showing a significant increase of both ATX and LPA in the blood under a specific disease.

Effects of herbal medicine Dai-Kenchu-to on anorectal function in children with severe constipation

AIM

We administered the herbal medicine Dai-Kenchu-To (DKT) to children with severe chronic constipation or with severe constipation after surgery for anorectal malformations. We then objectively assessed the effect of DKT on anorectal function by manometric study in addition to using a clinical scoring system.

PATIENTS AND METHODS

Ten children with severe chronic constipation and 5 children with severe constipation after surgery for anorectal malformations were assessed. These 15 children received 0.3 g/kg/day of DKT for periods ranging from 3 months to 1 year. We objectively assessed their bowel function, sphincter function and rectal reservoir function by anorectal manometry and clinical scoring.

RESULTS

In 10 children with severe chronic constipation, the clinical score after administration of DKT (7.2 +/- 0.8) improved significantly compared with that before administration of DKT (4.6 +/- 2.9) (p < 0.02). The threshold sensation volume and the maximum tolerable volume after administration of DKT significantly (p < 0.05; p < 0.01) decreased (128 +/- 63 ml vs. 69 +/- 18 ml; 229 +/- 99 ml vs. 144 +/- 47 ml), and rectal compliance after administration of DKT also significantly (p < 0.05) decreased (12.4 +/- 10.9 ml/cmH(2)O vs. 4.7 +/- 3.9 ml/cmH(2)O).

CONCLUSION

The present study demonstrated that DKT had a favorable clinical effect on severe constipation in children, and anorectal manometry showed an improvement in their rectal reservoir functions. It appears that the results were secondary to DKT-stimulated peristalsis of the intestine, which promoted regular bowel habits.

Hepatic stellate cell damage may lead to decreased plasma ADAMTS13 activity in rats

ADAMTS13 is gaining attention, because its deficiency causes thrombotic thrombocytopenic purpura. Although its regulatory mechanism is not fully understood, we wondered if hepatic stellate cells (HSCs) play a role, because ADAMTS13 mRNA is exclusively expressed in the liver and primarily in HSCs. Plasma ADAMTS13 activity was markedly reduced in dimethylnitrosamine-treated rats, where HSC apoptosis is an essential event, but not in carbon tetrachloride- or thioacetamide-treated rats without HSC apoptosis. Furthermore, plasma ADAMTS13 activity was also reduced in 70% hepatectomized rats, where HSC loss occurs. These results suggest that HSC may be involved in the regulation of plasma ADAMTS13 activity.

The herbal medicine inchin-ko-to (TJ-135) induces apoptosis in cultured rat hepatic stellate cells

Use of herbal remedies in the treatment of various diseases has a long tradition in Eastern medicine and the liver diseases are not an exception. In their use, lack of elucidation of mechanism(s) as well as randomized, placebo-controlled clinical trials has been a problem. Recently, we and others reported that inchin-ko-to (TJ-135), one of herbal remedies, suppressed hepatic fibrosis in animal models. In the course of clarifying the mechanism, we directed our focus on hepatic stellate cells (HSCs), playing a pivotal role in hepatic fibrosis, and found that rat HSCs cultured with TJ-135 changed their morphology to star-like configuration with thin, slender and dendritic processes with fewer stress fibers, which might be the features in apoptosis. In fact, TJ-135 induced HSC apoptosis in a time- and concentration-dependent manner as judged by the nuclear morphology, quantitation of cytoplasmic histone-associated DNA oligonucleosome fragments and caspase 3 activity. In HSCs treated with TJ-135, increased expression of p53 and decreased expression of Bcl-2 and phosphorylated Akt and Bad were determined. HSC apoptosis is shown to be involved in the mechanisms of spontaneous resolution of rat hepatic fibrosis and the agent which induces HSC apoptosis has been shown to reduce experimental hepatic fibrosis in rats. Thus, the induction of HSC apoptosis could be the mechanism how TJ-135 works on the resolution of hepatic fibrosis. Our current data may shed light on the novel effect of the herbal remedy.

A clinical analysis of prognostic parameters of survival in children with congenital diaphragmatic hernia

BACKGROUND

Congenital diaphragmatic hernia (CDH) still has a high mortality because of accompanying lung hypoplasia and persistent pulmonary hypertension. Although prognostic parameters based on perinatal measurements have been proposed, our ability to accurately predict the surgical results remains insufficient.

METHODS

We treated 55 infants with CDH from 1981 to 2004. Among them, 46 patients presented respiratory distress within the first 24 hours of life. Results of surgical treatment in the 46 infants were retrospectively correlated with gender, birth weight, gestational age at diagnosis, laterality, cardiac anomalies, diaphragmatic defect area, contents of herniated viscera, and the great vessel diameters measured by echocardiography.

RESULTS

Out of 46 CDH neonates, 27 (58.7 %) survived and 19 (41.3 %) died aged 3 to 17 days. Non survivors had a significantly larger diaphragmatic defect and more frequent liver herniation. Out of possible predictive parameters studied, an index of the main pulmonary artery (cross-sectional area/diaphragmatic defect area ratio) most closely correlated with the surgical outcomes.

CONCLUSIONS

The postoperative prognosis of CDH infants does not depend only on pulmonary hypoplasia, but also on other factors including the magnitude of abdominal visceral herniation. In this series of patients, the most reliable prognostic predictor was a clinical index reflecting the degree of both pulmonary hypoplasia and diaphragmatic maldevelopment.

[Is minimal skin incision and partial sternotomy approach for congenital heart defects less invasive?; evaluation of SIRS on ventricular septal defect]

OBJECTIVES

Minimally invasive cardiac surgery (MICS) has been developed to offer patients the benefits of open heart operations with limited skin incision. But it is unclear whether this procedure is less invasive. We evaluate postoperative duration of systemic inflammatory response syndrome (SIRS) on ventricular septal defect (VSD).

METHODS

From August 1997 to March 2000, 47 patients VSD underwent total repair by the minimal skin incision and lower partial median sternotomy (MICS group). We compared duration of SIRS between MICS and conventional method group (n = 14) and between early MICS and recent MICS group. We also evaluated the relationship between MICS and postoperative clinical course.

RESULTS

Duration of SIRS of MICS group were obviously shorter than that of conventional method group (p < 0.05). That of recent MICS group is also significantly shorter than that of early MICS group (p < 0.05). Operative time, bypass time, postoperative intubation time and length of skin incision were related duration of SIRS.

CONCLUSIONS

The results of this study indicate that MICS for VSD may be less invasive method.

Zebrafish leopard gene as a component of the putative reaction-diffusion system

It has been suggested, on a theoretical basis, that a reaction-diffusion (RD) mechanism underlies pigment pattern formation in animals, but as yet, there is no molecular evidence for the putative mechanism. Mutations in the zebrafish gene, leopard, change the pattern from stripes to spots. Interestingly each allele gives a characteristic pattern, which varies in spot size, density and connectivity. That mutations in a single gene can generate such a variety of patterns can be understood using a RD model. All the pattern variations of leopard mutants can be generated in a simulation by changing a parameter value that corresponds to the reaction kinetics in a putative RD system. Substituting an intermediate value of the parameter makes the patterns similar to the heterozygous fish. These results suggest that the leopard gene product is a component of the putative RD mechanism.

Validation of the defining characteristics of body image disturbance in Japan

PURPOSE

To examine the validity of the nursing diagnosis body image disturbance and to specify its major and minor defining characteristics in Japanese culture.

METHODS

A qualified sample of 149 RNs with an average of 10 years of clinical experience and knowledge of nursing diagnosis was given a questionnaire consisting of 21 defining characteristics from NANDA, 8 additional items from the literature, and 2 distracting characteristics.

FINDINGS

Four major diagnostic content validation (DCV) scores of 0.75 and higher and 15 minor defining characteristics with DCV scores from 0.60 to 0.74 were identified.

CONCLUSIONS

This study provides a foundation for further study of culturally appropriate defining characteristics for use in Japan.

Power spectral analysis of heart rate variability in type A females during a psychomotor task

This study investigated changes in autonomic nervous activities due to psychological stress in Type A females. Eight Type A and eight Type B females performed a psychomotor task for 30 minutes. Power spectral analysis of heart rate variability (HRV) was used to examine the autonomic nervous activities. Results showed the low frequency (LF) component and LF/HF ratio in Type A females increased after the onset of the task. There were no significant differences in task performance between Type A and Type B females. The subjective mental workload increased gradually in Type A females during the tasks, whereas in Type B females this parameter did not change in a consistent manner. The results suggest that the sympathetic nervous system in Type A females was more stimulated by the task and Type A females felt a greater subjective mental workload than did Type B females.

Application of ultra short acting beta blockade (esmolol) in pediatric open heart surgery: a trial in total anomalous pulmonary venous return

BACKGROUND

In the repair of total anomalous pulmonary venous return (TAPVR) under cardiopulmonary bypass, esmolol, ultra short acting beta blocker, was applied to obtain low heart rate and weak ventricular contraction under mild hypothermic cardiopulmonary bypass.

METHODS

Five infants aged from 14 to 158 days with an average of 70 days, underwent a primary or palliative repair of TAPVR. The type of anomalous return was supracardiac type (2), infracardiac (2), and intracardiac (1). A primary repair was done in three for isolated TAPVR with bypass time of 65 to 76 minutes, and a palliative repair for two with complex anomalies with bypass time of 64 and 87 minutes.

RESULTS

There was one operative death from cerebral bleeding in an infant with complex TAPVR who underwent simultaneous pulmonary banding.

CONCLUSION

This strategy seems to be applicable in pediatric cardiac surgery when aortic cross-clamping is better to be avoided and the surgery is mainly limited to the atrial level.

[Repair of total anomalous pulmonary venous return using an ultra-short acting beta blockade (esmolol)--case reports]

In 2 infants with asplenic syndrome associated with total anomalous pulmonary venous return (TAPVR), a repair of TAPVR was done under mild hypothermic cardiopulmonary bypass (CPB) using esmolol, an ultra short-acting beta-blocker to obtain good operative field without aortic-cross clamping. Both cases were weaned from CPB uneventfully. Pulmonary venous obstruction was not found after surgery. This strategy seems to be applicable in pediatric cardiac surgery which is mainly limited to the atrial level.

Incoherent pattern detection using a liquid-crystal active lens

Incoherent pattern detection by a simple imaging system using a liquid-crystal active lens is proposed. The imaging system works as a spatial filtering system with a rewritable phase-only filter. We found that, in the incoherent matched filtering system, a conventional phase-only filter has a higher optical efficiency but a lower pattern discrimination than a complex filter. To improve the pattern discrimination ability, we optimized the phase-only filter by using simulated annealing and a genetic algorithm. We designed phase-only filters that have discrimination ability comparable with that in a complex filter. The performance of optimized phase-only filters is experimentally demonstrated.

[Iatrogenic injury of tracheobronchial membranous wall]

Tracheobronchial injuries remain uncommon, but they are of great significance, because they can result in death or substantinal functional compromise. Such injuries are mostly from blunt trauma and motor vehicle accidents, but there also is an incidence of penetrating thoracic trauma inclunding iatrogenic accidents. Three cases of iatrogenic injury of tracheobronchial membranous wall were reported. Two cases were tear at the membraneous portion of the left main bronchus and trachea by forceful endotracheal intubation. Another case was tracheal membranous wall injury during operation at blunt dissection for esophageal carcinoma. We reported the emergent managements for iatrogenic injury of tracheobroncheal membranous wall in differents 3 ways. We should select the best treatment according to the condition of the patients and situation of the injury.

Spontaneous aortic thrombosis in a neonate with multiple thrombi in the main branches of the abdominal aorta

Spontaneous aortic thrombosis in the neonate is a rare entity with a high mortality rate. The present patient, who was diagnosed after showing haematuria and cyanosis, underwent aortic thrombectomy with a Fogarty catheter through a left thoracotomy, but died of sepsis, disseminated intravascular coagulation and multiple organ failure. Autopsy revealed multiple residual thrombi in the main branches of the abdominal aorta and necrosis of the abdominal organs despite a patent thoracoabdominal aorta. In patients with no blood flow in the main branches of the abdominal aorta on preoperative examination, removal of thrombi, including those in the main branches of the abdominal aorta, might be performed in a single, early and aggressive procedure.

[Subaortic stenosis in coarctation or interruption of the aorta--changes of left ventricular outflow tract dimension after aortic arch repair and pulmonary artery banding]

Left ventricular outflow tract (LVOT) dimension was measured in seven patients with coarctation (CoA) or interruption (IAA) of the aorta before and after aortic arch repair and pulmonary artery banding. The age of patients ranged 3 to 69 (mean 16) days, the weight 3.0 to 3.9 (mean 3.4) kg. Associated cardiac anomalies were VSD in 6, MA and DORV in 1. In five patients compared by ultrasound, preoperative LVOT dimension ranged from 3.5 to 5.0 (mean 4.4) mm with the ratio to the normal aortic valve dimension (n-AVD; 16.6 x BSA0.6) from 54 to 82 (mean 69)%. Postoperative dimension increased 5.0 to 7.4 (mean 5.7) mm and the ratio to the n-AVD increased 65 to 89 (mean 80)%. In three patients compared by LV graphy, preoperative LVOT dimension ranged from 4.0 to 4.5 (4.2) mm and the ratio ranged from 61 to 72 (68)%. Postoperative dimension increased from 4.5 to 6.7 (5.3) mm, and 74 to 80 (78)% to n-AVD after operation. Postoperative pressure gradients between LV and ascending aorta in each patient were 1 to 9 (mean 6) mmHg. In any patients, LVOT obstruction did not advance after aortic arch repair and pulmonary artery banding.

Kinetic analysis of AUC-dependent saturable clearance of liposomes: mathematical description of AUC dependency

The objective of this study was to examine the AUC dependency of saturable hepatic clearance (CLh) of liposomes and to postulate a mathematical model to describe the characteristics. The AUC dependency of saturable CLh was examined under intravenous rapid administration at various doses. The CLh increased with increasing blood concentration but decreased with the increase of AUC at each dose. In addition, the relationship between AUC and CLh was consistent with that observed in previously reported infusion studies. These experimental data confirm the AUC dependency of saturable CLh of liposomes. A mathematical model was developed for this AUC dependency. The decrease of CLh was described by the uptake amount (X) as follows: CLh = CLm(1-X/Xm), where CLm and Xm represent the maximum uptake clearance and the maximum uptake amount, respectively. The rate equation for uptake was analytically solved as CLh = X/AUC = Xm/AUC(1-exp(CLm/XmAUC)). Uptake clearance can be described by CLm, Xm, and AUC, and so uptake clearance is constant if AUC is constant. These experimental analyses and theoretical considerations show the validity of the AUC-dependent saturable CLh of liposomes.

Kinetic modeling of liposome degradation in blood circulation

The aim of this study is to develop a kinetic model for the quantitative evaluation of, and to examine dose dependency in liposome degradation in blood circulation in vivo. Multilamellar liposomes labeled with 3H-inulin were administered intravenously into rats and the time courses of blood concentration and urinary excretion of 3H-inulin were measured. The dosages of liposomes were fixed at 1, 5, and 100 mumolPCkg-1. Remarkable saturation was found in the time courses of both blood concentration and urinary excretion. Then a kinetic model for the degradation of liposomes in blood was developed, assuming that the degradation follows the first order rate process for each dose. The model fitted the observed time courses of excreted 3H-inulin well, and dose dependency could be observed in the rate constants for liposome degradation, which are more sensitive than urinary excretion of 3H-inulin. The degradation rate constant correlated well with the uptake rate constant, which suggests the same underlying mechanism for both uptake and degradation. These results indicate the usefulness of kinetic modeling in the quantitative evaluation of liposome degradation in blood circulation in vivo.

Saturable, non-Michaelis-Menten uptake of liposomes by the reticuloendothelial system

Multilamellar vesicles (300-350 nm) were infused into the rat femoral vein at the rate of 4, 40 and 400 nmol phosphatidycholine min-1 for 6 h using [3H]inulin as an aqueous marker. The time courses of blood concentration of vesicles, normalized for infusion rate, were not superimposable, showing the non-linearity of liposome disposition in the blood circulation. These time courses of blood concentration were well fitted by a single Michaelis-Menten equation. On the other hand, the time courses of tissue content could not be so accommodated. Additionally, the observed relationship between the uptake of liposomes by the liver and their clearance from it and other organs differed essentially from a simulation based on Michaelis-Menten type saturable kinetics. Therefore, it is suggested that there is a time-dependent non-Michaelis-Menten type process in the phagocytosis of macrophages in the reticuloendothelial system.

An epidemiological study on cancer in certified arsenic poisoning patients in Toroku

A mortality study has been made to assess the carcinogenic effect of arsenic exposure by analyzing a group of certified chronic arsenic poisoning patients at a small mining village in Japan. When compared with expected number of deaths, based on sex-, age-specific mortality of Japanese in 1975, '80 and '85, all cancer, cancer of respiratory system and cancer of bladder, kidney and other and unspecified urinary organs showed a significant excess over the expected number. Divided by employment history, death due to all cancers, to respiratory cancer and to urinary tract cancer showed a significant excess among former workers of the mine. Classified into four cohorts by both employment history and smoking habit, death from respiratory cancer showed a significant excess only in the cohort respiratory cancer showed a significant excess only in the cohort of former workers with smoking history, suggesting an interaction between exposure to arsenic and smoking. Eight cases among ten respiratory cancers and two urinary tract cancer cases were accompanied by cancer of other organs, including Bowen's disease.

Improvement of spatial resolution properties of image intensifier-TV digital systems with a multiple-narrow-slit beam imaging technique

Multiple-slit beam imaging technique with an image intensifier (II)-TV digital system has been developed to remove scatter and veiling glare while high x-ray beam utilization is maintained. Although the contrast and signal-to-noise ratio (SNR) are improved with this technique, the overall image quality obtainable with an II-TV digital system is still limited due to low spatial resolution, which is mainly caused by the large pixel size, i.e., by the small matrix size used. In order to overcome the limitation of the pixel size, we have developed a new method of improving the resolution properties of the II-TV digital system by use of a multiple-slit assembly (MSA) having a narrow slit width. When the slit width of the MSA is narrower than the pixel size of the II-TV digital system, two signals from a given slit due to different MSA placements may be detected by the same pixel in different image frames, and the detected signals of the slit images are mapped to a large matrix. In this way, the spatial resolution in the direction perpendicular to the slit openings can be improved along with the increased contrast and SNR as the scatter and veiling glare can be removed. Experimental results are presented, and the effect of an anisotropic resolution property on the overall image quality is discussed.

Inhibitory effects of quinolone antibacterial agents on gamma-aminobutyric acid binding to receptor sites in rat brain membranes

The specific binding of 3H-labeled gamma-aminobutyric acid ([3H]GABA) to synaptic plasma membranes from rat brains was inhibited by various quinolonecarboxylic acid derivatives (quinolones), and these inhibitions were concentration dependent. The binding of [3H]muscimol to GABAA sites was also inhibited. These inhibitory potencies differed widely among the quinolones examined. The Dixon plots showed that a newly developed difluorinated quinolone, NY-198 [1-ethyl-6,8-difluoro-1,4-dihydro-7-(3-methyl-1-piperazinyl)-4-oxo-3- quinolinecarboxylic acid hydrochloride], competitively inhibits the receptor bindings of [3H]GABA and [3H]muscimol. In conclusion, our findings suggest that the inhibition of GABA binding to receptors (including uptake sites) in the brain may be involved in the induction of epileptogenic neurotoxicities by quinolones.

Investigation of basic imaging properties in digital radiography. 11. Multiple slit-beam imaging technique with image intensifier-TV digital system

We are developing a digital x-ray imaging system using a multiple slit assembly (MSA) and an image intensifier (II)-TV digital system. The advantage of this approach is that the scatter from an object and the veiling glare in the II-TV system can be reduced significantly while the x-ray utilization is maintained much better than that with a single slit-beam technique. The quality of reconstructed images is related to many parameters such as the slit width, the lead spacer, the number of image frames, and the reconstruction algorithm. In this study, reduction of scatter and veiling glare was measured quantitatively, and image artifacts were analyzed. It was found that the fraction of scatter and veiling glare can be reduced to approximately 0.01-0.1 by use of the MSA imaging technique, and that the magnitude of the fractions is strongly dependent upon the slit width and the lead spacer of the MSA used. The artifacts are caused by inaccuracies in the slit width, lead spacer, and scan motion, and by undersampling of image data. The overlap scanning technique was effective in reducing the magnitude of these artifacts in the reconstructed image.

Basic imaging properties of a large image intensifier-TV digital chest radiographic system

The basic imaging properties of a large (57 cm) image intensifier (I.I.)-TV digital imaging system were examined to determine the effects of various physical parameters on the quality of the digital chest images obtained, and also to explore the clinical usefulness of the system. The characteristic curve of the digital system, which relates the output pixel value to the input relative x-ray intensity, was measured with an aluminum stepwedge. MTFs were determined using slit images, and the veiling-glare fraction was measured with a lead-disk technique. Noise Wiener spectra were obtained from uniformly exposed images. The current limitations of the large II-TV digital chest system are its low spatial resolution, and the presence of large amounts of veiling glare and structure mottle. Advantages of this system over other digital chest imaging systems include the high speed of image data acquisition and the capability of "real-time" dynamic imaging of the chest at a radiation dose comparable to that in conventional radiography of the chest.

Investigation of basic imaging properties in digital radiography 10. Structure mottle of II-TV digital imaging systems

Single-frame images obtained with image intensifier (II)-TV digital systems contain a large amount of structure mottle. In the present study, we examined several II-TV digital systems by use of Wiener spectral analysis and noted considerable variation of the structure mottle over the wide spatial frequency range. We found that the structure mottle in these systems may originate in the input phosphor, the output phosphor, and/or the electronic components, and that the Wiener spectra of structure mottle seem to depend on the specific combination of these components. The results of observer performance studies indicated that structure mottle can significantly decrease the detection of low-contrast objects in a single-frame image when the exposure incident on the II is greater than approximately 0.1 mR. In addition, we showed that the structure mottle can be removed by subtraction of a uniformly exposed mask. This simple procedure will improve the quality of radiologic images obtained with II-TV digital systems. Note, however, that the structure mottle is largely eliminated by subtraction in digital subtraction angiography (DSA) images.