miR-146a regulates emphysema formation and abnormal inflammation in the lungs of two mouse models

miR-146a, a microRNA (miRNA) that regulates inflammatory responses, plays an important role in many inflammatory diseases. Although an in vitro study had suggested that miR-146a is involved in abnormal inflammatory response, being a critical factor in the pathogenesis of chronic obstructive pulmonary disease (COPD), in vivo evidence of its pathogenic role in COPD remains limited. Eight-week-old male B6(FVB)-Mir146tm1.1Bal/J [miR-146a knockout (KO)] and C57BL/6J mice were intratracheally administered elastase and evaluated after 28 days or exposed to cigarette smoke (CS) and evaluated after 5 mo. miR-146a expression was significantly increased in C57BL/6J mouse lungs due to elastase administration (P = 0.027) or CS exposure (P = 0.019) compared with that in the control group. Compared with C57BL/6J mice, elastase-administered miR-146a-KO mice had lower average computed tomography (CT) values (P = 0.017) and increased lung volume-to-weight ratio (P = 0.016), mean linear intercept (P < 0.001), and destructive index (P < 0.001). Moreover, total cell (P = 0.006), macrophage (P = 0.001), neutrophil (P = 0.026), chemokine (C-X-C motif) ligand 2/macrophage inflammatory protein-2 [P = 0.045; in bronchoalveolar lavage fluid (BALF)], cyclooxygenase-2, and matrix metalloproteinase-2 levels were all increased (in the lungs). Following long-term CS exposure, miR-146a-KO mice showed a greater degree of emphysema formation in their lungs and inflammatory response in the BALF and lungs than C57BL/6J mice. Collectively, miR-146a protected against emphysema formation and the associated abnormal inflammatory response in two murine models.NEW & NOTEWORTHY This study demonstrates that miR-146a expression is upregulated in mouse lungs because of elastase- and CS-induced emphysema and that the inflammatory response by elastase or CS is enhanced in the lungs of miR-146a-KO mice than in those of control mice, resulting in the promotion of emphysema. This is the first study to evaluate the protective role of miR-146a in emphysema formation and the associated abnormal inflammatory response in different in vivo models.

Blood Eosinophil Count as a Predictive Biomarker of Chronic Obstructive Pulmonary Disease Exacerbation in a Real-World Setting

Introduction

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death, and COPD exacerbation worsens the prognosis. Eosinophilic airway inflammation is a COPD phenotype that causes COPD exacerbation and is correlated with peripheral blood eosinophil count. We analyzed real-world data of COPD patients to assess the risk factors of COPD exacerbation focusing on blood eosinophils.

Materials and Methods

Patients with COPD who visited our hospital between January 1, 2018, and December 31, 2018, were recruited, and their background information, spirometry data, laboratory test results, and moderate-to-severe exacerbation events during the one-year follow-up period were collected from the electronic medical records and analyzed. The COPD exacerbation risk factors were assessed using univariate and multivariate logistic regression analyses.

Results

Twenty-two of 271 (8.1%) patients experienced moderate-to-severe exacerbation. Patients with exacerbation showed worse pulmonary function, and we found that a high blood eosinophil count (≥350 cells/μL; p=0.014), low % FEV1 (<50%; p=0.002), increase in white blood cell (≥9000 cells/μL; p=0.039), and use of home oxygen therapy (p=0.005) were risk factors for future exacerbations. We also found a strong correlation between eosinophil count cut-offs and exacerbation risk (r = 0.89, p < 0.001). On the other hand, there was no relation between exacerbation risk and inhalation therapy for COPD.

Conclusion

In a real-world setting, peripheral blood eosinophil count could be a predictor of future COPD exacerbation.

Exposure to the heated tobacco product IQOS generates apoptosis-mediated pulmonary emphysema in murine lungs

Pulmonary emphysema is predominantly caused by chronic exposure to cigarette smoke (CS). Novel tobacco substitutes, such as heated tobacco products (HTPs), have emerged as healthier alternatives to cigarettes. IQOS, the most popular HTP in Japan, is advertised as harmless compared with conventional cigarettes. Although some studies have reported its toxicity, few in vivo studies have been conducted. Here, 12-wk-old C57BL6/J male mice were divided into three groups and exposed to air (as control), IQOS aerosol, or CS for 6 mo. After exposure, the weight gain was significantly suppressed in the IQOS and CS groups compared with the control (-4.93 g; IQOS vs. air and -5.504 g; CS vs. air). The serum cotinine level was significantly higher in the IQOS group than in the control group. The neutrophils and lymphocyte count increased in the bronchoalveolar lavage fluid of the IQOS and CS groups compared with those in the control group. Chronic IQOS exposure induced pulmonary emphysema similar to that observed in the CS group. Furthermore, expression levels of the genes involved in the apoptosis-related pathways were significantly upregulated in the lungs of the IQOS-exposed mice. Cytochrome c, cleaved caspase-3, and cleaved poly (ADP-ribose) polymerase-1 were overexpressed in the IQOS group compared with the control. Single-stranded DNA and TdT-mediated dUTP nick-end labeling-positive alveolar septal cell count significantly increased in the IQOS group compared with the control. In conclusion, chronic exposure to IQOS aerosol induces pulmonary emphysema predominantly via apoptosis-related pathways. This suggests that HTPs are not completely safe tobacco products.

A Case of a Pregnant Woman Diagnosed as Having ALK-rearranged Lung Adenocarcinoma

A 28-year-old woman who was 34 weeks pregnant was admitted with complaints of cough and blood-stained sputum. After delivery of the baby at 37 weeks gestation, computed tomography and magnetic resonance imaging revealed a tumor in the right lung and a 15-mm brain metastasis. A diagnosis of lung adenocarcinoma was made, cT4N3M1b (stage IV disease) by pleural fluid cytology. Additional testing for anaplastic lymphoma kinase (ALK) fusion protein showed a strongly positive result, which was then confirmed by fluorescence in situ hybridization. The patient was started on treatment with alectinib, and the tumor and brain metastasis had almost vanished by 2 months after the start of this treatment. In the literature, there are 59 reports of lung cancer diagnosed during pregnancy, including two cases of cancer with expression of ALK fusion protein and five cases showing epidermal growth factor receptor mutation. The type of mutation should be taken into consideration while selecting for the appropriate therapeutic strategy.

Usual Interstitial Pneumonia Pattern in the Lower Lung Lobes as a Prognostic Factor in Idiopathic Pleuroparenchymal Fibroelastosis

BACKGROUND

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare interstitial pneumonia that is characterized by stiffness in both the upper lobes and pleura, which is evident on high resolution computed tomography (HRCT) of the chest. However, prognostic factors for IPPFE have not been identified yet.

OBJECTIVE

We aimed to investigate the clinical prognostic factors affecting survival in patients with IPPFE.

METHODS

Between April 2009 and September 2017, we enrolled 36 patients who were clinically diagnosed with IPPFE, using HRCT. These patients were classified as either short survival (dead within 12 months from the diagnosis of IPPFE) or long survival (survived for greater than 12 months) groups. We retrospectively analyzed the clinical characteristics, serum markers, pulmonary function test results, and HRCT findings.

RESULTS

Twelve patients were classified into the short survival and 24 were categorized into long survival categories. At the time of diagnosis, the incidence of coexistence of a usual interstitial pneumonia (UIP) pattern in the lower lobes on HRCT in the short survival was significantly higher than that in the long survival. Multivariate analysis revealed that a UIP pattern in the lower lobes on HRCT was the only independent variable for poor prognosis. The median survival time from diagnosis in patients with IPPFE was 24 months. Of these patients with IPPFE, the survival time with a UIP pattern was significantly shorter than in those without a UIP pattern.

CONCLUSION

Our findings suggest that a UIP pattern in the lower lobes at the time of diagnosis was an independent prognostic factor for IPPFE.

Pneumothorax caused by cystic and nodular lung metastases from a malignant uterine perivascular epithelioid cell tumor (PEComa)

Perivascular epithelioid cell tumors (PEComas) are mesenchymal neoplasms with immunoreactivity for both melanocytic and smooth muscle markers. PEComas occur at multiple sites, and malignant PEComas can undergo metastasis, recurrence and aggressive clinical courses. Although the lung is a common metastatic site of PEComas, they usually appear as multiple nodules but rarely become cystic or cavitary. Here, we describe a female patient whose lungs manifested multiple cystic, cavity-like and nodular metastases 3 years after the resection of uterine tumors tentatively diagnosed as epithelioid smooth muscle tumors with uncertain malignant potential. This patient's subsequent pneumothorax necessitated video-assisted thoracoscopic surgery, and examination of her resected lung specimens eventually led to correcting the diagnosis, i.e., to a PEComa harboring tuberous sclerosis complex 1 (TSC1) loss-of-heterozygosity that originated in the uterus and then metastasized to the lungs. The administration of a gonadotropin-releasing hormone analogue later stabilized her clinical course. To the best of our knowledge, the present case is the first in the literature that associates PEComas with a TSC1 abnormality. Additionally, the pulmonary manifestations, including imaging appearance and pneumothorax, somewhat resembled those of lymphangioleiomyomatosis, a representative disease belonging to the PEComa family. Although PEComas are rare, clinicians, radiologists and pathologists should become aware of this disease entity, especially in the combined clinical setting of multiple cystic, cavity-like, nodular lesions on computed tomography of the chest and a past history of the tumor in the female reproductive system.

Atomic step-and-terrace surface of polyimide sheet for advanced polymer substrate engineering

Typical thermostable and flexible polyimide polymers exhibit many excellent properties such as strong mechanical and chemical resistance. However, in contrast to single-crystal substrates like silicon or sapphire, polymers mostly display disordered and rough surfaces, which may result in instability and degradation of the interfaces between thin films and polymer substrates. As a step toward the development of next-generation polymer substrates, we here report single-atom-layer imprinting onto the polyimide sheets, resulting in an ultrasmooth 0.3 nm high atomic step-and-terrace surface on the polyimides. The ultrasmooth polymer substrates are expected to be applied to the fabrication of nanostructures such as superlattices, nanowires, or quantum dots in nanoscale-controlled electronic devices. We fabricate smooth and atomically stepped indium tin oxide transparent conducting oxide thin films on the imprinted polyimide sheets for future use in organic-based optoelectronic devices processed with nanoscale precision. Furthermore, toward 2D polymer substrate nanoengineering, we demonstrate nanoscale letter writing on the atomic step-and-terrace polyimide surface via atomic force microscopy probe scratching.

Preoperative internal biliary drainage is superior to external biliary drainage in liver regeneration and function after hepatectomy in obstructive jaundiced rats

OBJECTIVE

To examine the differences in regeneration rates and functions of the liver at the time of and after hepatectomy in obstructive jaundiced rats with preoperative external and internal biliary drainage.

SUMMARY BACKGROUND DATA

The significance of biliary drainage before surgery is controversial in patients with obstructive jaundice.

METHODS

After biliary obstruction for 7 days, rats were randomly divided into three groups: obstructive jaundice and hepatectomy (OJ-Hx), external biliary drainage and hepatectomy (ED-Hx), and internal biliary drainage and hepatectomy (ID-Hx). The OJ-Hx group underwent hepatectomy without biliary drainage; the other two groups underwent hepatectomy after biliary drainage for 7 days. At the time of hepatectomy, all rats were provided with internal biliary drainage. On days 0, 1, 2, 3, and 7 after hepatectomy, the DNA synthesis rate and the concentrations of adenine nucleotides and malondialdehyde in the liver were determined as markers of the hepatic regeneration rate, energy status, and lipoperoxide concentration, respectively. Portal endotoxin concentrations were measured and serum hyaluronic acid concentrations were determined as an indicator of hepatic endothelial function.

RESULTS

The relative liver weight was significantly higher in the ID-Hx group than in the OJ-Hx group on days 1, 3, and 7 after hepatectomy and than in the ED-Hx group on days 1 and 2. The rate of hepatic DNA synthesis was significantly higher in the ID-Hx group than in the OJ-Hx and ED-Hx groups on day 1. The rate was similar in the ED-Hx and ID-Hx groups on day 2 but was significantly higher than in the OJ-Hx group. The hepatic malondialdehyde concentration was significantly higher on day 1 in the ED-Hx group than in the other two groups. It was lowest in the ID-Hx group throughout the study. Both biliary drainage procedures lowered the portal endotoxin concentration and serum hyaluronic acid concentration at the time of hepatectomy. The serum hyaluronic acid concentration was lowest in the ID Hx group. Hepatic adenine triphosphate concentrations and energy charge levels were similar among the three groups.

CONCLUSION

Although both external and internal biliary drainage before hepatectomy improved serum liver function tests, portal endotoxin concentration, and serum hyaluronic acid concentration at the time of surgery, preoperative internal biliary drainage was superior to external drainage, as evidenced by the better liver regeneration and function after hepatectomy.

The combined method: a novel access technique for fetal endoscopic surgery

BACKGROUND/PURPOSE

To develop practical and less invasive techniques for fetal endoscopic surgery, new methods of lifting the uterine wall to allow fetal surgery without maternal laparotomy were developed and assessed.

METHODS

Fetal endoscopic surgical procedures, including tracheostomy and umbilical vascular cannulation, were performed using one of the three methods to enter the uterus without maternal laparotomy in pregnant goats (n = 6; 105 to 115 days' gestation): (1) direct uterine lifting with an air-cushion device; (2) indirect uterine lifting, in which the uterine wall was fixed to the maternal abdominal wall using balloon tip ports inserted percutaneously by Seldinger's method, then the maternal abdomen was lifted mechanically; and (3) combined method, in which low pressure CO2 (5 mm Hg for initial inflation and 2 mm Hg for maintenance) was insufflated into the uterus in addition to the indirect uterine lifting cited above.

RESULTS

The direct uterine lifting caused massive injury of myometrium and uterine membranes. The creation of intrauterine space and the protection of the membranes were not accomplished effectively by the indirect uterine lifting only. The combined method provided the adequate intrauterine space and excellent endoscopic visibility for completion of the endoscopic procedures with minimal uterine injury.

CONCLUSION

The fetal endoscopic surgery may be accomplished simply and safely by the combined method, a novel technique of uterine lifting to allow fetal surgery without maternal laparotomy.

Cholesterol and bile acid metabolism after selective portal vein ligation

AIM

To examine the regulatory effect of bile acid level on bile acid synthesis in the liver.

METHODS

The portal branch perfusing left lateral and median lobes of the liver was ligated in rats and the activities of hepatic microsomal cholesterol 7 alpha-hydroxylase, the rate-limiting enzyme of bile acid synthesis, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, and intrahepatic concentrations of cholesterol and bile acids were determined in the liver lobes deprived of and supplied with portal blood on Days 0, 1, 2, 4, and 7 after selective portal vein ligation (SPVL).

RESULTS

In the portal vein (PV)-ligated lobes, liver weight decreased, hepatic cholesterol concentration was unchanged, and microsomal cholesterol concentration increased after SPVL. In the PV-nonligated lobes, liver weight increased, hepatic cholesterol concentration increased, and microsomal cholesterol concentration was unchanged. There were no significant differences in the activities of HMG-CoA reductase and cholesterol 7 alpha-hydroxylase among the PV-ligated and PV-nonligated lobes and the sham-operated controls. Intrahepatic bile acid level increased significantly in the PV-nonligated lobes for 4 days after SPVL, whereas those were essentially constant in the PV-ligated and the sham-operated control liver. Despite significant changes in the concentrations of intrahepatic cholesterol and bile acid, no significant correlations were observed between these concentrations and the activities of cholesterol 7 alpha-hydroxylase.

CONCLUSIONS

SPVL causes atrophy and hypertrophy of the PV-ligated and nonligated liver lobes, respectively, without any significant changes in cholesterol and bile acid synthesis. Intrahepatic concentrations of bile acids and cholesterol have no regulatory effect on cholesterol 7 alpha-hydroxylase activity in the SPVL rat model.

Hepatic adenine nucleotides and microsomal cholesterol 7 alpha-hydroxylase activity in the obstructed and freely draining lobes of the liver after selective bile duct obstruction

BACKGROUND

The effect of selective bile duct obstruction (SBDO) on hepatic reserve function of the bile duct obstructed (BDO) and nonobstructed freely draining (FD) lobes of the liver is obscure.

METHODS

The bile duct branches draining from the left lateral and median lobes of the liver were ligated for 4 and 10 days in rats, and hepatic reserve functions in BDO and FD lobes were assessed by microsomal cholesterol 7 alpha-hydroxylase activities and by hepatic adenine nucleotides and energy charge levels. The values were compared with those in the sham-operated control liver. Cholesterol 7 alpha-hydroxylase activities were determined by gas-liquid chromatography--mass spectrometry, and hepatic adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) levels with high-pressure liquid chromatography.

RESULTS

The histological examination of the BDO lobes showed proliferation and formation of new bile ductules and fibrous connective tissues linking portal areas. Microsomal cholesterol 7 alpha-hydroxylase activities, hepatic energy charge and each adenine nucleotide level did not differ between FD and BDO lobes, and the values were similar to those in the sham-operated liver.

CONCLUSIONS

Selective bile duct obstruction shows no adverse effects on microsomal and mitochondrial functions in both the BDO and FD lobes of the liver.

Hepatic adenine nucleotides and microsomal cholesterol 7 alpha-hydroxylase activity in the obstructed and freely draining lobes of the liver after selective bile duct obstruction

BACKGROUND

The effect of selective bile duct obstruction (SBDO) on hepatic reserve function of the bile duct obstructed (BDO) and nonobstructed freely draining (FD) lobes of the liver is obscure.

METHODS

The bile duct branches draining from the left lateral and median lobes of the liver were ligated for 4 and 10 days in rats, and hepatic reserve functions in BDO and FD lobes were assessed by microsomal cholesterol 7 alpha-hydroxylase activities and by hepatic adenine nucleotide and energy charge levels. The values were compared with those in sham-operated control liver. Cholesterol 7 alpha-hydroxylase activities were determined by gas-liquid chromatography-mass spectrometry, and hepatic adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) levels with high-pressure liquid chromatography.

RESULTS

The histological examination of the BDO lobes showed proliferation and formation of new bile ductules and fibrous connective tissue linking portal areas. Microsomal cholesterol 7 alpha-hydroxylase activities, hepatic energy charge and adenine nucleotide levels did not differ between FD and BDO lobes, and the values were similar to those in the sham-operated liver.

CONCLUSIONS

Selective bile duct obstruction shows no adverse effects on microsomal and mitochondrial functions in either BDO or FD lobes of the liver.

Functional contribution of preoperative portal vein occlusion to hepatectomy. With special reference to hepatic energy charge and DNA synthesis after hepatectomy in rats

OBJECTIVE

To examine possible functional contributions of preoperative portal branch ligation before hepatectomy (PBL-Hx).

DESIGN

Rats were randomly divided into 3 groups. In the PBL-Hx group, the portal branch supplying the left lateral and median lobes of the liver was ligated and the corresponding lobes (48% of the whole liver) were excised 2 days later. In the sham groups (one 68% Hx; the other 47% [hereafter, sham-67% Hx, and sham-47% Hx]), originally ligated lobes and left lateral and caudate lobes, similar to the excised liver volume in the PBL-Hx group, respectively, were excised 2 days after sham operation without PBL.

MAIN OUTCOME MEASURES

Hepatic adenine nucleotides and energy charge, which are essential for vital function of hepatocytes, and liver regeneration were assessed by the DNA synthesis rate and weight before Hx and on days 1, 2, 3, and 7 after Hx.

RESULTS

The remaining liver weight was restored similarly in the PBL-Hx and sham-47% Hx groups and more rapidly than in the sham-68% Hx group. Further enhancement of DNA synthesis did not occur after Hx in the PBL-Hx group, and hepatic energy charge did not decrease. In contrast, hepatic DNA synthesis was significantly activated depending on the excised liver volume in both the sham-Hx groups and was accompanied by corresponding decreases in hepatic energy charge.

CONCLUSION

Preoperative PBL has a functional advantage because the recovery of the remaining liver volume is not impaired and hepatic energy charge is preserved with no further enhancement of DNA synthesis after Hx.

Sequential changes of energy charge, lipoperoxide level, and DNA synthesis rate of the liver following biliary obstruction in rats

To clarify the effects of obstructive jaundice on the liver, sequential changes of hepatic energy charge, the concentrations of adenine nucleotides and malondialdehyde, DNA synthesis rate, and histology of the liver were examined on the day before and Days 1, 2, 4, 7, and 14 after biliary obstruction in rats and compared with those of sham-operated controls. Foci of necrotic hepatocytes were present on Days 1 and 2 and mitoses of the hepatocytes were frequently observed with a peak on Day 2 in the jaundiced liver. Marked proliferation of bile ductules were subsequently observed on Days 7 and 14, resembling biliary cirrhosis. The DNA synthesis rate was significantly activated after bile duct obstruction with its peak on Day 2, more than nine times higher than the control value and returned to the control level on Day 14. Hepatic ATP concentration and energy charge gradually declined with prolonged jaundice and significantly lower levels persisted after Day 7 compared with the controls. The malondialdehyde level in the jaundiced liver gradually increased and became significantly higher on Day 14. We conclude that obstructive jaundice decreases hepatic energy charge and increases the lipoperoxide level. In the initial stage of obstructive jaundice, the hepatocytes proliferate associated with activated DNA synthesis probably to compensate hepatic damage; however, prolonged obstructive jaundice induces functional hepatic injury possibly necessitating biliary drainage.

Hepatic resection for hepatolithiasis and long-term results

BACKGROUND

Hepatic resection is an established procedure for treating patients with hepatolithiasis. The long-term results after hepatic resection for hepatolithiasis were appraised.

STUDY DESIGN

Of 127 patients with hepatolithiasis seen between 1973 and 1993, 43 patients underwent hepatic resection, and constituted the basis of this study.

RESULTS

There was one operative death (operative mortality rate of 2.3 percent) and three deaths as a result of concomitantly associated cholangiocellular carcinoma. Of the remaining 39 patients, the complete stone clearance rate was 67 percent with operation alone, but reached 87 percent when cholangioscopy was used. Operative morbidity was recorded in five patients (12 percent), but they recovered with conservative therapy. Stones recurred in 15 percent of patients after a mean follow-up period of four years (range of three to six years). Eleven (28 percent) of 39 patients died after hepatectomy as a result of related diseases after a mean follow-up of 6.2 years. These 11 patients had associated biliary drainage procedures. They experienced a higher mortality rate (p < 0.05) than patients who did not have biliary drainage.

CONCLUSIONS

We conclude that hepatic resection is adequate treatment for hepatolithiasis. The patients having additional biliary drainage procedures had a higher mortality, but one cannot reach conclusions about the negative effect of the drainage procedures because the drainage procedures were done in a selected and not a randomized manner.

Postoperative follow-up of patients with type IVA choledochal cysts after excision of extrahepatic cyst

BACKGROUND

This study concerns patients who have choledochal cyst with intrahepatic and extrahepatic involvement (type IVA cyst). The extent of excision and the necessity of hepatectomy, including the intrahepatic cyst in these patients have not been clarified.

STUDY DESIGN

We have performed excision of the extrahepatic cyst with hepaticojejunostomy upon 13 patients with type IVA cyst during a 16 year period. The present study was done to examine the size of the anastomotic opening by direct cholangiography two weeks postoperatively. The long-term results were assessed to find the appropriate operative management for patients with type IVA cysts.

RESULTS

Intrahepatic cysts were present in both hepatic lobes in 11 patients (85 percent). None of the patients had carcinoma after excision of extrahepatic cyst during the follow-up period, which ranged from two months to 16 years. Postoperative late complications occurred in three patients (23 percent), hepatolithiasis in two and cholangitis in one. The anastomotic opening of hepaticojejunostomy was 13.3 +/- 4.5 mm in diameter two weeks postoperatively, which was not significantly different when compared with that in ten patients without late complications (13.4 +/- 4.9 mm). The late complications were successfully treated with either antibiotics or percutaneous transhepatic cholangioscopy, and none required a reoperation.

CONCLUSIONS

The results suggest that additional hepatectomy is not required because carcinoma has rarely occurred from the intrahepatic cyst. Excision of an extrahepatic cyst with a wide hepaticojejunostomy is an acceptable operative management for patients with type IVA cysts.

Lumbar artery pseudoaneurysm: an unusual cause of a retroperitoneal hematoma: report of a case

Pseudoaneurysm of the lumbar artery is a rare complication of penetrating trauma. We present herein a case thought to have been caused by a blow to the left flank without any evidence of a stab wound. In this patient, the diagnosis of a first lumbar artery pseudoaneurysm with a retroperitoneal hematoma was confirmed by computed tomography (CT) findings, after which transcatheter embolization was successfully performed.

Higher serum retinol-binding protein concentration in Indonesian neonates in Surabaya than Japanese neonates in Kobe

The concentrations of serum retinol-binding protein (RBP), prealbumin (PA) and vitamin A of Indonesian neonates were compared with those of Japanese neonates. The mean serum concentrations of both PA and vitamin A did not differ significantly in Indonesian and Japanese neonates. Indonesian neonates had significantly higher serum RBP (2.75 +/- 0.87 mg/dl, mean +/- SD) than Japanese neonates (1.65 +/- 0.55 mg/dl, p less than 0.01). The molar ratio of vitamin A:RBP in Indonesian infants was significantly lower than in Japanese infants (p less than 0.02), and this in turn is indicative of increased concentrations of retinol-free RBP in the plasma of Indonesian neonates. The results suggest that RBP metabolism in Indonesian neonates differs from that in Japanese neonates.

Characterization of a radioimmunoassay to determine plasma total renin

The determination of plasma total renin is useful not only as a tool to investigate the physiology of hypertension but also as a marker for Wilms' tumor. A radioimmunoassay (RIA) system to determine plasma total renin was newly developed using monoclonal antibodies specific for both inactive and active renin (inactive + active = total); in this study, an effort was made to confirm that this RIA system truly determines plasma total renin concentrations. First, it was found that this monoclonal antibody stains only the juxtaglomerular apparatus of the kidney. Second, the data determined by the RIA were compared with those obtained by the conventional enzymatic method: samples were activated, and renin activity was assayed by measuring angiotensin I. The coefficient of the data obtained by this RIA system and by the conventional method was 0.921 (p less than 0.01) based on all 89 samples, and 0.809 (p less than 0.01) based on 86 of the 89 samples whose values were less than 600 pg/ml by RIA. As a result of these studies, it was concluded that the newly developed RIA system does determine total renin levels in patients' plasma.

Impairment of superoxide release by alveolar macrophage in rats exposed to oxygen and vitamin E

We examined the digitonin-stimulated release of superoxide by alveolar macrophages (AMs) from young rats exposed to greater than 95% oxygen for 24-168 h. AMS were obtained by lung lavages, and the release of superoxide stimulated by digitonin was measured by using cytochrome C reduction. The total cell count of lung lavages decreased at 24 and 168 h of oxygen exposure (p less than 0.05 for both). The contamination of polymorphonuclear cells (PMNs) was less than 1% up to 120 h of oxygen exposure, and at 168 h PMNs increased to 5% of total cells in lung lavages. The viability of AMs was greater than 95% up to 72 h and then decreased to 90% at 120 h of oxygen exposure and 87% at 168 h. Digitonin-stimulated superoxide release by AMs recovered from lung lavages in rats exposed to hyperoxia showed a slight increase during the first 48 h. However, oxygen exposure for 72 h or more caused a significant decrease of the stimulated superoxide release of AMs compared to AMs from control rats. This decline in stimulated superoxide release of AMs resulting from hyperoxia was not prevented by vitamin E treatment.

Inhibitory action of bilirubin on superoxide production by polymorphonuclear leukocytes

To assess the interaction of bilirubin with albumin and to determine the site of bilirubin toxicity in cells, a study was made of the O2- production of neonatal neutrophils (PMNs) by two different stimulators: (1) concanavalin A (Con A) plus cytochalasin D (Cyt D), which acts on the cell surface, and (2) phorbol myristate acetate, which acts intracellularly. PMNs that had been separated from cord blood were incubated for 60 min at 37 degrees C in the solution with different molar ratios of bilirubin/albumin (unbound bilirubin, ranging from 0.35 to 3.92 micrograms/dl). The unbound bilirubin was determined by peroxidase oxidation method. A PMN viability of more than 96% was maintained after the incubation in each of solutions. The O2- production rate of PMNs stimulated by Con A plus Cyt D was inhibited in the presence of unbound bilirubin levels as low as 1.12 micrograms/dl, and the rate decreased as the levels of unbound bilirubin rose. The O2- production rate stimulated by Con A plus Cyt D was more remarkably inhibited than that by phorbol myristate acetate, which directly activates intracellular protein kinase C. These findings suggest that bilirubin toxicity to PMN can be shown at levels of unbound bilirubin as low as those in hyperbilirubinemic sera, and the critical site at which bilirubin exerts its toxicity is mainly in membrane level rather than on intracellular functions.