Prepregnancy body mass index and glycated albumin in the third trimester may predict infant complications in gestational diabetes mellitus: a retrospective cohort study

Background

Maternal hyperglycemia, obesity, and hypertension with gestational diabetes mellitus (GDM) are risk factors for infant complications. This study aimed to investigate maternal factors and glycemic control indicators that affect infant complications in GDM.

Methods

We conducted a retrospective cohort study including 112 mothers with GDM and their infants. Multivariate logistic regression analysis was used to investigate the variables associated with good and adverse infant outcomes. We determined the cutoff values of variables that showed a significant difference in the multivariate logistic regression analysis for predicting infant complications by performing receiver operating characteristic curve analysis.

Results

In the multivariate logistic regression analysis, prepregnancy BMI and GA in the third trimester were significantly related to good and adverse infant outcomes (adjusted odds ratios [aORs], 1.62; 95% CIs 1.17-2.25, p = 0.003 and aORs, 2.77; 95% CIs 1.15-6.64, p = 0.022, respectively). The cutoff values for prepregnancy BMI and GA in the third trimester were 25.3 kg/m2 and 13.5%, respectively.

Conclusions

The importance of weight control before pregnancy and the usefulness of GA in the third trimester to predict infant complications were suggested in this study.

Comparison of Acute Phase Thymus and Activation-Regulated Chemokine (TARC) Levels in Food Protein-Induced Enterocolitis Syndrome and IgE-Dependent Food Allergy

Introduction: Patients with food protein-induced enterocolitis syndrome (FPIES) have elevated thymus and activation-regulated chemokine (TARC) levels in the acute phase. However, to the best of our knowledge, no study has evaluated TARC levels in the acute phase of immunoglobulin E-dependent food allergy (IgE-FA). If TARC elevation is a specific response to FPIES among FAs, TARC measurement may help distinguish between FPIES and IgE-FA. Thus, we investigated acute phase TARC levels in patients with FPIES and IgE-FA. Methods: Thirty-one episodes in 16 patients with FPIES and 20 episodes (13 were anaphylaxis) in 20 patients with IgE-FA were included. Patients with eczema were excluded. Serum TARC levels within 6 h of allergic reaction onset and age-adjusted TARC ratios (TARC levels divided by age-specific normal TARC values) were compared between the groups. Results: The median age was 1.1 and 3.6 years in the FPIES and IgE-FA groups, respectively (P < 0.001). The median (range) serum TARC (pg/mL) levels were significantly higher in the FPIES group than in the IgE-FA group [1,283 (410-3,821) versus 377 (109-1,539); P < 0.001]. The median (range) age-adjusted TARC ratios were also significantly higher in the FPIES group [2.56 (0.57-7.86) versus 1.08 (0.15-2.17); P < 0.001]. The area under the curve (AUC) for TARC to distinguish FPIES from IgE-FA was 0.926, and the AUC for the age-adjusted TARC ratio was 0.850. The odds ratio for FPIES diagnosis per 1,000 pg/mL increase in TARC was 31.6 (P = 0.002), and the odds ratio adjusted by age was 17.1 (P = 0.016). Conclusion: Acute phase TARC levels were higher in patients with FPIES than in patients with IgE-FA. The increase in acute phase TARC levels was considered to be a specific response to FPIES among FAs. Measurement of TARC levels in the acute phase may help differentiate FPIES from IgE-FA.

The Association Between Serum Zinc Levels and Anthropometric Measurements and Nutritional Indicators in Children With Idiopathic Short Stature

Background

Zinc (Zn) is an essential trace element, and its deficiency causes various symptoms, such as anemia, short stature, and poor weight gain, in children. Several studies have reported an association between Zn deficiency and short stature in children. However, few studies have reported on the relationship between serum Zn levels, body mass index (BMI), and nutritional indicators such as albumin, amino acids, and vitamin D.

Methods

We retrospectively analyzed the data of 56 children with idiopathic short stature. We investigated the mean serum Zn levels and the relationships among serum Zn levels and height standard deviation score (SDS), bodyweight SDS, BMI SDS, hemoglobin (Hb), albumin, alkaline phosphatase (ALP), insulin-like growth factor-1 (IGF-1), 25-hydroxyvitamin D (25(OH)D), and amino acid levels.

Results

The mean serum Zn levels of the study participants were 70.3±10 µg/dL. Serum Zn levels correlated significantly with weight SDS (r=0.472, p<0.001) and BMI SDS (r=0.416, p<0.001). In contrast, no significant association was found between serum Zn levels and height SDS (r=0.217, p=0.078). We found significant positive correlations between serum Zn levels and Hb and IGF-1 SDS (Hb: r=0.333, p=0.012; IGF-1 SDS: r=0.372, p=0.00478). Serum Zn levels were not correlated with albumin, ALP, 25(OH)D, and amino acid levels.

Conclusions

Serum Zn levels are associated with anthropometric measurements, especially body weight and BMI. It is important to evaluate Zn levels in children who fail to thrive, even in developed countries.

Differences in Thymus and Activation-Regulated Chemokine and Squamous Cell Carcinoma Antigen 2 Levels in Food Protein-Induced Enterocolitis Syndrome and Atopic Dermatitis

INTRODUCTION

We previously reported that thymus and activation-regulated chemokine (TARC) levels measured after vomiting are useful predictors of a food protein-induced enterocolitis syndrome (FPIES) diagnosis. However, interpreting TARC levels in patients with eczema is difficult, as the levels are similarly elevated in patients with eczema caused by atopic dermatitis (AD). Therefore, we aimed to investigate whether it is possible to predict whether FPIES or AD is responsible for elevated TARC levels by simultaneously measuring TARC and squamous cell carcinoma antigen 2 (SCCA2), another T-helper type 2 biomarker.

METHODS

Twenty-one episodes in 11 patients with FPIES (FPIES group) and 42 age-matched patients with AD (AD group) were included in this study. Serum TARC and SCCA2 levels were measured, and those values and relative ratios were compared between groups.

RESULTS

The median age was 1.1 years in the FPIES group and 1.6 years in the AD group (p = 0.492). The median (interquartile range [IQR]) serum TARC concentration was significantly higher in the FPIES group than in the AD group (2,486 [1,815-4,097] pg/mL and 1,451 [1,201-1,751] pg/mL, respectively; p = 0.002). The median (IQR) SCCA2 concentration was significantly higher in the AD group than in the FPIES group (1.9 [1.3-2.9] pg/mL and 0.8 [0.6-1.5] pg/mL, respectively; p < 0.001). After matching, the analysis using stratified TARC values revealed no significant difference in TARC values between the FPIES and AD groups; however, the TARC/SCCA2 ratio was significantly higher in the FPIES group.

CONCLUSION

Assessing the relative TARC/SCCA2 ratio may help predict whether elevated TARC levels measured after vomiting are caused by FPIES or AD.

Clinical usefulness of glycated albumin and glycated albumin-to-glycated hemoglobin ratio of gestational diabetes mellitus in late pregnancy for predicting infant complications

BACKGROUND

Gestational diabetes mellitus (GDM) with poorly controlled glycemia is associated with poor pregnancy outcomes. However, adequate markers for glycemic control in GDM have not been fully evaluated.

METHODS

We retrospectively studied 77 patients with GDM and their infants. Mean glycated albumin (GA), glycated hemoglobin (HbA1c), and GA/HbA1c in GDM were compared between two groups stratified by the presence or absence of infant complications (complications or non-complications). We assessed the predictability of infant complications in GA, HbA1c, and GA/HbA1c of women with GDM by receiver operating characteristic analysis (ROC).

RESULTS

In complications and non-complications, GA and GA/HbA1c were significantly associated with neonatal hypoglycemia (13.9% vs. 13.0%, p < 0.001 and 2.49 vs. 2.33, p < 0.001, respectively), respiratory disorders (13.7% vs. 13.2%, p = 0.013 and 2.48 vs. 2.34, p < 0.001, respectively), myocardial hypertrophy (14.5% vs. 13.0%, p < 0.001 and 2.59 vs. 2.33, p < 0.001, respectively), and large for gestational age (14.5% vs. 13.1%, p < 0.001 and 2.58 vs. 2.34, p < 0.001, respectively). Compared with each infant complication in ROC, GA and GA/HbA1c had higher area under the curve than HbA1c. Especially, GA and GA/HbA1c had highest AUC in predicting myocardial hypertrophy and large for gestational age (GA; 0.92 and 0.92, GA/HbA1c; 0.91 and 0.86, respectively). Although statistically significant positive correlations were found between GA and GA/HbA1c and the number of infant complications (GA: r = 0.417, p < 0.001; GA/HbA1c: r = 0.408, p < 0.001), their correlations were weak.

CONCLUSION

Compared with HbA1c, GA and GA/HbA1c of GDM in late pregnancy might be useful for predicting infant complications arising from GDM.

Potential of Thymus and Activation-Regulated Chemokine (TARC) as a Prognostic Biomarker of Food Protein-Induced Enterocolitis Syndrome (FPIES) Caused by Egg Yolk

BACKGROUND

Several recent studies have reported egg yolk-associated food protein-induced enterocolitis syndrome (FPIES) in Japan. We previously reported the usefulness of post-emetic thymus and activation-regulated chemokine (TARC) levels for the diagnosis and evaluation of symptom severity in FPIES caused by solid foods including egg yolk. However, there are no studies on the usefulness of TARC as a prognostic biomarker.

OBJECTIVE

The aim of the study was to evaluate the post-emetic TARC levels, clinical symptoms, and post-index event results of the egg yolk oral food challenge test (OFC), and retrospectively investigate predictive factors of the subsequent OFC result.

METHOD

This retrospective study included 12 patients with egg yolk FPIES. The following long-term management protocol for egg yolk FPIES was mandatory for study inclusion: Patients visited the emergency department, met the diagnostic criteria of FPIES, and underwent an egg yolk OFC 6-12 months after complete elimination of egg yolk. If the result of the OFC was positive, the patient underwent the OFC every year until it was negative. We analyzed a total of 20 episodes (12 department visits and eight positive OFCs). The blood test data, including post-emetic TARC level and symptom severity, were compared between the next-OFC-positive group and the next-OFC-negative group. In addition, tolerance development over follow-up was analyzed.

RESULTS

The median (range) ages of the next-OFC-positive and negative groups were 11 (6-33) and 10 (7-21) months, respectively. The median (range) serum TARC (pg/mL) level was 5,208 (2,009-8,147) in the next-OFC-positive group, which was significantly higher (p = 0.004) than that in the next-OFC-negative group, which was 1,803 (905-3,754). There were no significant differences in other hematological results. The next-OFC-positive group had greater severity compared to the next-OFC-negative group (p = 0.026). The remission rate was approximately 30% at 24 months and 80% at 36 months.

CONCLUSION

Post-emetic TARC levels may predict the short-term prognosis of egg yolk FPIES after approximately 1 year and could be useful for the management of egg yolk FPIES.

A Pediatric Case of Ketosis-Prone Type 2 Diabetes Requiring Insulin Therapy

In recent years, cases of diabetic ketoacidosis (DKA) or ketosis as the initial manifestation of diabetes with a similar clinical course to that of type 2 diabetes have been reported. This phenotype has been recognized as ketosis-prone type 2 diabetes (KPD). Most cases of KPD occur in adults, and the typical clinical course is that patients are often able to wean off insulin therapy after initial treatment. We report a pediatric case of ketosis-prone type 2 diabetes requiring insulin therapy with four years of follow-up. Our case suggests that patients with KPD may require strict management, including weight control, compared with patients with typical type 2 diabetes.

20p11.23-p11.21 deletion in a child with hyperinsulinemic hypoglycemia and GH deficiency: A case report

Some neonatal hypoglycemias have genetic origins. For instance, mutation in forkhead box protein A2 (FOXA2), located on chromosome 20p11.21, has recently been reported to cause hyperinsulinemic hypoglycemia and hypopituitarism. Here, we report a case of hyperinsulinemic hypoglycemia and GH deficiency (GHD) with 20p11.23-p11.21 deletion, which included FOXA2. The boy was diagnosed with hyperinsulinemic hypoglycemia during the neonatal period and subsequently administered diazoxide for treatment. His blood glucose levels gradually stabilized, and the diazoxide dosage was slowly reduced and ultimately fully weaned. The patient was discharged at the age of 29 d. Unfortunately, the patient experienced recurrent hypoglycemia at 3 mo, and diazoxide administration was re-initiated. Further examination, including chromosomal microarray analysis, revealed a 2.48-Mb 20p11.23-p11.21 deletion that encompassed FOXA2. In addition, severe GHD was detected, and magnetic resonance imaging of the brain revealed pituitary stalk interruption. Accordingly, GH replacement therapy was started at 0.175 mg/kg/wk, and blood glucose levels were stabilized. Our report suggests that there are pathological conditions that can cause both hyperinsulinemic hypoglycemia and hypopituitarism and reaffirms the importance of evaluating not only insulin and congenital metabolic disorders but also pituitary function in patients with hypoglycemia.

[EVALUATION OF THE RELATIONSHIP BETWEEN THE SEVERITY OF SOLID FOOD PROTEIN-INDUCED ENTEROCOLITIS SYNDROME AND POST-EMETIC SERUM THYMUS AND ACTIVATION-REGULATED CHEMOKINE LEVELS]

BACKGROUND

We reported that post-emetic serum thymus and activation-regulated chemokine (TARC) levels may be a potential biomarker to diagnose solid food protein-induced enterocolitis syndrome (FPIES). However, there are no reports on the relationship between FPIES severity and serum TARC levels.

METHODS

The subjects were 13 cases of FPIES (hen's egg=10, Wheat=1, rice=1, short-neck clam=1) for a total of 22 events (7 emergency outpatient visits, 9 positive and 6 negative results of oral food challenge test). Serum TARC levels at 6 and 24 h after antigen ingestion were compared between the symptomatic and asymptomatic events and the mild-moderate and severe events. We also evaluated the correlation between vomiting duration and serum TARC levels.

RESULTS

The median serum TARC (pg/ml) in the asymptomatic, mild-moderate, and severe events were 546, 1093, and 3127 at 6 h after ingestion, and 910, 2053, and 6496 at 24 h after ingestion, respectively. The serum TARC level was significantly higher in the symptomatic events than the asymptomatic events, and it was significantly higher in the severe events than the mild-moderate events (p < 0.01). There was a moderate correlation between serum TARC levels and vomiting duration.

CONCLUSION

Post-emetic serum TARC correlates with the severity of FPIES. It is expected that this information will lead to an objective evaluation of the severity of FPIES.

Evaluation of the Diagnostic Accuracy of Thymus and Activation-Regulated Chemokine to Discriminate Food Protein-Induced Enterocolitis Syndrome from Infectious Gastroenteritis

BACKGROUND

Post-emetic elevation in thymus and activation-regulated chemokine (TARC) levels has been reported in patients with food protein-induced enterocolitis syndrome (FPIES); however, no studies have investigated differences in TARC levels between FPIES and other diseases.

OBJECTIVES

We evaluated the clinical usefulness of TARC measurement in differentiating between FPIES and infectious gastroenteritis.

METHODS

This study included 8 patients with solid-food FPIES (FPIES group; hen's egg [n = 6], rice [n = 1], and short-neck clam [n = 1]; a total of 11 episodes necessitating emergency department visit or positive result of oral food challenge test) and 17 patients with infectious gastroenteritis (control group), and all patients had no eczema. Post-emetic serum TARC levels and modified TARC levels (serum TARC value - normal mean for each age) were compared between the 2 groups.

RESULTS

The median (range) ages for the FPIES and control groups were 0.7 (0.5-6.2) and 1.8 (0.1-4.4) years, respectively (p > 0.05). In the FPIES and control groups, median (range) TARC levels were 2,911 (1,062-7,816) and 600 (277-2,034) pg/mL, and median (range) modified TARC levels were 2,204 (355-7,109) and 129 (0-1,314), respectively. The TARC and modified TARC levels were significantly higher in the FPIES group than in the control group (p < 0.001 for both).

CONCLUSION

In the absence of eczema, post-emetic serum TARC levels might be a potential diagnostic biomarker for distinguishing FPIES from infectious gastroenteritis.

Comparison of methemoglobin levels in food protein-induced enterocolitis syndrome and other gastrointestinal diseases in neonates

INTRODUCTION AND OBJECTIVES

Methemoglobinemia has been reported to be associated with severe food protein-induced enterocolitis syndrome (FPIES). However, no reports have evaluated methemoglobin (MHb) levels in FPIES without symptomatic methemoglobinemia or the usefulness of MHb measurement for the diagnostic prediction of FPIES. To evaluate the MHb levels of patients with neonatal-onset FPIES and determine whether MHb levels are higher in FPIES than in other gastrointestinal diseases.

PATIENTS AND METHODS

Eleven neonates with severe acute FPIES (FPIES group) and 139 neonates with other gastrointestinal diseases (non-FPIES group) were included in this study. Patient characteristics, symptoms, and venous blood test values (MHb, pH, HCO₃^-, and C-reactive protein) were evaluated.

RESULTS

The median age at onset was 16 days vs. 1 day; males comprised 64% vs. 46%, the median gestational age was 38 weeks vs. 38 weeks, the median birth weight was 2710g vs. 2880g, and the median hospitalization duration was 31 days vs. 6 days for the FPIES vs. non-FPIES groups, respectively. MHb (%) was higher in the FPIES group than in the non-FPIES group [median (range), 1.1 (0.6-10.9) and 0.6 (0.3-1.2), respectively, p<0.001]. There were no differences in terms of pH, HCO₃^-, and C-reactive protein (p>0.05). In the receiver operating characteristic analysis for FPIES diagnosis based on MHb (%), the area under the curve was 0.885, specificity was 97.1%, and sensitivity was 72.7% at a MHb cutoff of 1.0.

CONCLUSION

High MHb levels may help diagnose severe acute FPIES in neonates, but careful evaluation is needed.

Complications in Infants of Diabetic Mothers Related to Glycated Albumin and Hemoglobin Levels During Pregnancy

BACKGROUND

This study was conducted to investigate whether glycated albumin is a useful glycemic marker from the point of view of infant complications for monitoring glycemic control in pregnant women with diabetes or gestational diabetes mellitus.

METHODS

We retrospectively studied 42 Japanese infants of diabetic mothers and their mothers at our facility between May 2010 and July 2013. The mean glycated albumin and glycated hemoglobin levels were compared between mothers of infants with complications and those without complications. We used 15.8% as the cutoff value of glycated albumin and calculated the sensitivity and specificity of items that were significantly different between the two groups.

RESULTS

Glycated albumin was significantly higher in mothers of infants with hypoglycemia (15.5±1.8 vs. 13.8±1.2%, p = 0.001), respiratory disorders (15.6±1.8 vs. 13.9±1.2%, p < 0.001), hypocalcemia (15.7±2.1 vs. 14±1.2%, p = 0.004), myocardial hypertrophy (15.2±1.9 vs. 13.7±1%, p = 0.007), and large-for-date status (15.8±1.9 vs. 14±1.3%, p = 0.002). By contrast, considering hypoglycemia, glycated hemoglobin was not significantly different between the two groups. The sensitivity and specificity with 15.8% as the cutoff value of glycated albumin were as follows: hypoglycemia (70% and 81.2%), respiratory disorders (61.5% and 82.8%), hypocalcemia (62.5% and 84.4%), myocardial hypertrophy (87.5% and 79.4%), and large-for-date status (75% and 85.3%).

CONCLUSION

Glycated albumin is a useful marker of glycemic control considering infant complications during pregnancy. This study also suggests that evaluating both glycated hemoglobin and glycated albumin levels can lead to better glycemic control in pregnant women.

Anthropogenic disruption to the seismic driving of beach ridge formation: The Sendai coast, Japan

The expected geomorphic after-effects of the Mw 9.0 Tōhoku-oki earthquake of 11 March 2011 (eastern Japan) are summarized by a schematic model of seismic driving, which details seismogenic disturbances to sediment systems that affect the rate or timing of sediment delivery to coastlines over timescales of 10(2)-10(4)years. The immediate physical environmental responses to this high-magnitude earthquake included a large tsunami and extensive region-wide slope failures. Normally, slope failures within mountain catchments would have significant impacts on Japan's river and coastal geomorphology in the coming decades with, for example, a new beach ridge expected to form within 20-100 years on the Sendai Plain. However, human activity has significantly modified the rate and timing of geomorphic processes of the region, which will have impacts on likely geomorphic responses to seismic driving. For example, the rivers draining into Sendai Bay have been dammed, providing sediment traps that will efficiently capture bedload and much suspended sediment in transit through the river system. Instead of the expected ~1 km of coastal progradation and formation of a ~3m high beach ridge prior to the next large tsunami, it is likely that progradation of the Sendai Plain will continue to slow or even cease as a result of damming of river systems and capture of river sediments behind dams. The resulting reduction of fluvial sediment delivery to the coast due to modification of rivers inadvertently makes seawalls and other engineered coastal structures even more necessary than they would be otherwise.

Aftereffects of Subduction-Zone Earthquakes: Potential Tsunami Hazards along the Japan Sea Coast

The 2011 Tohoku-Oki Earthquake is a typical subduction-zone earthquake and is the 4th largest earthquake after the beginning of instrumental observation of earthquakes in the 19th century. In fact, the 2011 Tohoku-Oki Earthquake displaced the northeast Japan island arc horizontally and vertically. The displacement largely changed the tectonic situation of the arc from compressive to tensile. The 9th century in Japan was a period of natural hazards caused by frequent large-scale earthquakes. The aseismic tsunamis that inflicted damage on the Japan Sea coast in the 11th century were related to the occurrence of massive earthquakes that represented the final stage of a period of high seismic activity. Anti-compressive tectonics triggered by the subduction-zone earthquakes induced gravitational instability, which resulted in the generation of tsunamis caused by slope failing at the arc-back-arc boundary. The crustal displacement after the 2011 earthquake infers an increased risk of unexpected local tsunami flooding in the Japan Sea coastal areas.

Effectiveness of right or left radial approach for coronary angiography

The transradial approach for catheterization is becoming increasingly more popular. At present, the choice of the right or left radial artery depends on the operator's preference. We examined how the laterality influenced the effectiveness of the approach. Employing Judkins-type catheters, we performed coronary angiography in 232 patients with the left approach and in 205 patients with the right approach. Although access time did not differ between the two groups of patients, the duration of catheter manipulation was shorter in the left- than in the right-approach group (11.7 +/- 5.9 vs. 9.8 +/- 4.4 min; P < 0.001). Because of the shorter duration of catheter manipulation, the total procedural duration was shorter in the left-approach group (13.7 +/- 6.4 vs. 11.4 +/- 4.8 min; P < 0.001). The fluoroscopy time was shorter in the left- than in the right-approach group (3.7 +/- 2.5 vs. 5.0 +/- 3.3 min; P < 0.001). The amount of contrast material did not differ between the groups (79 +/- 27 vs. 83 +/- 25 ml). The rate of guidewire usage to engage the coronary ostium was higher in the right- than in the left-approach group because of the severe tortuosity of the right subclavian artery (20/205 vs. 0/232; P < 0.001). Thus, for operators with significant experience, the left radial approach may provide increased procedural efficacy for coronary angiography compared to the right radial approach.

Heme oxygenase-1 reduces murine monocrotaline-induced pulmonary inflammatory responses and resultant right ventricular overload

Monocrotaline (MT), a pyrrolizidine alkaloid, causes pulmonary hypertension (PH) in rats and is widely utilized to analyze the pathophysiology of PH. However, a murine PH model with which transgenic animals may be used has not been established. To establish a murine MT-induced PH model, we administered different amounts of MT and determined the extent of right ventricular (RV) overload and PH. We also examined the expression of heme oxygenase-1 (HO-1), a potential antistress protein in MT-treated animals, and evaluated the functional role of HO-1 by administering an HO-1 inhibitor. Significant pulmonary inflammation and RV hypertrophy were observed when mice were given 600 mg/kg weight of MT weekly for 8 weeks. In addition, elevated RV pressure and induction of HO-1 in lung and RV were observed with this dose of MT. Interestingly, inhibition of HO activity promoted inflammatory changes in the lung and the resultant RV hypertrophy. HO-1 may play defensive roles against murine MT-induced pulmonary inflammation and the resultant RV overload.

Heme oxygenase-1 inhibits atherogenesis in Watanabe heritable hyperlipidemic rabbits

BACKGROUND

Heme oxygenase-1 (HO-1) is proposed to have a variety of adaptive responses against oxidative stress. To examine the function of HO-1 against atherogenesis in vivo, we observed the effects of HO-1 inhibition on atherosclerotic lesion formation in Watanabe heritable hyperlipidemic rabbits (WHHL). Methods and Results- During 4 weeks of a 1% cholesterol diet, intravenous injections of Sn-protoporphyrin IX to inhibit HO-1 (S group, n=10) and saline as a control (C group, n=10) were given to 3-month-old WHHL rabbits. The percentages of en face atherosclerotic lesion areas in total descending aorta by Sudan IV staining (EFA) and the ratio of intima to media in microscopic atherosclerotic lesions in the ascending aortas (I/M) were calculated. Two different quantitative methods revealed significantly greater atherosclerotic lesions in the S group than the C group (EFA, P<0.001; I/M, P<0.005). HO-1 expression in atherosclerotic lesions was confirmed by Northern blot and immunohistochemical analyses. The dominant cell types expressing HO-1 were macrophages and foam cells, in which oxidized phospholipids were also accumulated. HO inhibition increased plasma and tissue lipid peroxide levels without affecting plasma lipid co osition.

CONCLUSIONS

These results suggest the possibilities that HO-1 has antiatherogenic properties in vivo and that the antiatherogenic properties of HO-1 are conducted through the prevention of lipid peroxidation.

Heme oxygenase-1 inhibits atherosclerotic lesion formation in ldl-receptor knockout mice

Heme oxygenase-1 (HO-1) is induced by a variety of conditions associated with oxidative stress. We demonstrated that mildly oxidized LDL markedly induces HO-1 in human aortic endothelial and smooth muscle cell cocultures and that its induction results in the attenuation of monocyte chemotaxis resulting from treatment with mildly oxidized LDL in vitro. To elucidate the role of HO-1 in the development of atherosclerotic lesions in vivo, we modulated HO-1 expression in LDL-receptor knockout mice fed high-fat diets. During 6-week high-fat diet trials, intraperitoneal injections of hemin (H group) or hemin and desferrioxamine (HD group) to induce HO-1, Sn-protoporphyrin IX to inhibit HO-1 (Sn group), and saline as control (C group) were performed. Both the H and HD groups showed significantly less mean atherosclerotic lesions in the proximal aorta compared with the C group, whereas the Sn group showed larger lesion compared with the C group. Modulation of HO expression and HO activities were confirmed by Northern blot analysis and HO activity assay. Immunohistochemical studies revealed significant HO-1 expression in atherosclerotic lesions, where oxidized phospholipids also localized. Major cell types expressing HO-1 were macrophages and foam cells in the lesions. HO modulations affected plasma lipid hydroperoxide (LPO) levels and nitrite/nitrate levels. These results suggest that HO-1, induced under hyperlipidemia, functioned as an intrinsic protective factor against atherosclerotic lesion formation, possibly by inhibiting lipid peroxidation and influencing the nitric oxide pathway.