Haemaphysalis longicornis tick bites are a possible cause of red meat allergy in Japan.

Recent studies revealed that Amblyomma or Ixodes tick bites may cause red meat allergy, in which galactose-α-1,3-galactose (α-Gal) is a major IgE-binding epitope. The incidence of red meat allergy is high in Shimane Prefecture, as is tick-transmitted Japanese spotted fever. Therefore, we speculated that tick bites may cause these meat allergies. The carbohydrate α-Gal was detected in the salivary gland protein of Haemaphysalis longicornis (H. longicornis), the vector for Japanese spotted fever, by immunoblotting using anti-α-Gal antibody. H. longicornis salivary gland protein-specific IgE was detected in the sera of 24 of 30 patients with red meat allergies. Sensitization to tick salivary gland protein containing α-Gal is possibly a major etiology of red meat allergy; the carbohydrate plays a crucial role in its allergenicity. These results further indicate that the α-Gal epitope is present not only in Amblyomma or Ixodes, but also in Haemaphysalis.

Effects of IL6 C-634G polymorphism on tooth loss and their interaction with smoking habits.

OBJECTIVE: To examine the association between an IL6 (Interleukin-6) polymorphism (C-634G or rs1800796) and tooth loss, and an interaction between the polymorphism and smoking habits for the loss. MATERIAL AND METHODS: Our subjects were 4917 check-up examinees ages 35-69. They reported tooth loss and lifestyle in a questionnaire. We regressed the number of teeth on the IL6 genotype, gender, age, smoking, drinking, diabetes, hypertension, physical activity, energy intake, education, and brushing. We further estimated multivariate-adjusted odds ratios (ORs) for having <20 teeth. RESULTS: Participants with a GG genotype tended to have less teeth than those with CC; ß = -0.798 (95% confidence interval [CI] = -1.501--0.096). Subjects with a GG genotype were more likely to have <20 teeth than those with CC; OR was 1.56 (95% CI = 1.08-2.25). Association between current smoking and tooth loss was stronger among those with GG than among those with CC. In a multiple regression analysis, a significant interaction was found between GG genotype and current smoking in the prediction of tooth loss (P = 0.018). CONCLUSION: The IL6 C-634G polymorphism was significantly associated with tooth loss. Our results suggest greater effects of smoking on tooth loss in GG genotype individuals.

Laminin γ-1 and collagen α-1 (VI) chain are galactose-α-1,3-galactose-bound allergens in beef.

BACKGROUND: Sensitization to the carbohydrate galactose-α-1,3-galactose (α-Gal) has been reported in patients with beef allergy. However, the proteins responsible for this allergy have not yet been identified. This study aimed to identify beef proteins that predominantly react with serum IgE in Japanese patients with beef allergy. METHODS: Sera were collected from 29 patients with beef allergy who had allergic reaction(s) such as urticaria, abdominal pain, vomiting, and anaphylactic shock after ingestion of beef and pork; the sera tested positive for IgE against beef and pork. IgE-binding proteins were detected by immunoblotting sera from the patients and identified using a combination of two-dimensional gel electrophoresis and peptide mass fingerprinting techniques. The involvement of carbohydrate in the binding of IgE to allergens was examined by periodate treatment and an inhibition assay with cetuximab by immunoblotting. Specific IgE binding to cetuximab was measured using the CAP-fluorescent enzyme immunoassay. RESULTS: Two IgE-binding proteins (240 kDa and 140 kDa) were detected in beef extract and identified as laminin γ-1 and the collagen α-1 (VI) chain from Bos taurus, respectively. Periodate treatment or the inhibition assay resulted in the loss of IgE binding to these proteins. Immunoblotting with anti-α-Gal antibody revealed the presence of α-Gal on the 240- and 140-kDa beef proteins. The amount of IgE bound to cetuximab was significantly correlated with that to beef in the patients with beef allergy. CONCLUSION: The carbohydrate moiety (α-Gal) on laminin γ-1 and collagen α-1 (VI) chain are possibly common IgE-reactive proteins in the Japanese patients with beef allergy.

Thymic stromal lymphopoietin expression is increased in the horny layer of patients with atopic dermatitis.

Thymic stromal lymphopoietin (TSLP) is known for its capacity to induce CD11c(+) myeloid dendritic cells to promote T helper type 2 (Th2)-skewed inflammatory responses. Although increased expression of TSLP was reported in the lesional skin of limited numbers of patients with atopic dermatitis (AD), the relationships between the degree of TSLP expression in the skin and the severity of AD, epidermal barrier function and eruption type remain to be elucidated. The aim of this study was to examine the relationships between the degree of TSLP expression in the skin and the severity of AD, eruption type and epidermal barrier function using a non-invasive method in a sizeable group of the patients. Stratum corneum tissue was obtained from AD patients by tape stripping, and the stratum corneum TSLP (scTSLP) expression level was evaluated using a TSLP-specific antibody followed by image analysis. The correlations between the scTSLP intensity and the severity scoring of AD (SCORAD) index and epidermal barrier function, such as stratum corneum hydration and transepidermal water loss (TEWL), were analysed. The changes in the scTSLP level induced by the application of moisturizer were also examined. The scTSLP expression level was increased in AD patients compared with healthy subjects and was correlated with SCORAD, especially with the dry skin score, and stratum corneum hydration. Moisturizer application resulted in reduced scTSLP levels. The scTSLP level can be used as a biomarker of AD severity and particularly epidermal barrier status.

Recombinant high molecular weight-glutenin subunit-specific IgE detection is useful in identifying wheat-dependent exercise-induced anaphylaxis complementary to recombinant omega-5 gliadin-specific IgE test.

BACKGROUND: Wheat-dependent exercise-induced anaphylaxis (WDEIA) is a special form of food allergy typically induced by exercise after ingestion of wheat products. We identified wheat omega-5 gliadin and high molecular weight-glutenin subunit (HMW-glutenin) as major allergens for WDEIA and clarified that simultaneous detection of serum IgE binding to synthetic epitope peptides of these allergens identifies more than 90% of WDEIA patients. However, the short synthetic peptides are not suitable for CAP-fluorescent enzyme-immunoassay (CAP-FEIA), which is widely utilized for detecting allergen-specific IgE. OBJECTIVE: In this study, we constructed a CAP-FEIA with recombinant HMW-glutenin, and evaluated its usefulness in identifying the patients with WDEIA. METHODS: Recombinant HMW-glutenin was expressed as histidine-tag protein in E. coli and purified by histidine-tag affinity column. Wheat, gluten, recombinant omega-5 gliadin, epitope peptide of HMW-glutenin, native and recombinant HMW-glutenin specific IgE in the sera from 48 patients with WDEIA, 16 patients with atopic dermatitis (AD) who had no immediate allergic reaction after wheat ingestion and 12 healthy controls were determined by using CAP-FEIA method. RESULTS: In 16 AD patients without wheat allergy 12 of them (75%) had positive results for native HMW-glutenin test in contrast to epitope peptide of HMW-glutenin (12.5%) and recombinant HMW-glutenin test (12.5%). These results indicate the native HMW-glutenin test has low specificity. Sensitivity and specificity of the IgE test with recombinant HMW-glutenin were 16.7% and 92.9%. These are well compatible with results obtained by using epitope peptide of HMW-glutenin. However, sensitivity and specificity reached to 93.8% and 92.9%, when the test was combined to the test with recombinant omega-5 gliadin. CONCLUSIONS AND CLINICAL RELEVANCE: We demonstrated that recombinant HMW-glutenin is best for CAP-FEIA system in point of stability and specificity and confirmed that detection of specific IgE against recombinant HMW-glutenin is useful for diagnosis of WDEIA when combined with the CAP-FEIA (recombinant omega-5 gliadin) test.

Association between forest and greenspace walking and stress-coping skills among workers of Tsukuba Science City, Japan: A cross-sectional study.

Objectives: Recently, "sense of coherence" (SOC) as a concept of stress-coping, has been gaining considerable attention. Although many studies have investigated the factors related to strong SOC, we found little evidence about the associations between SOC and habits that are easy to perform in everyday life. The aim our study was to examine the prevalence of workers who engage in forest walking and greenspace walking and examine their association with SOC score. Study design: A cross-sectional study. Methods: An anonymous, self-report web questionnaire was conducted in November 2017. The study population included 19481 workers belonging to the Tsukuba Science City Network and data of 6466 participants (3965 men and 2501 women) were analyzed. Results: The percentage of participants who engage in forest and greenspace walking at least once a year were 55.9% and 75.9%, respectively. Associations between forest/greenspace walking and SOC score were calculated using Chi-squared tests. Multinomial logistic regression analyses with SOC score group (strong/middle/weak) as a dependent variable and forest/greenspace walking as explanatory variables were performed. Statistically significant positive associations were observed between strong SOC and those who engaged in forest/greenspace walking after adjusting for socioeconomic factors. The odds ratios for strong SOC were 3.65 (95% CI â€‹= â€‹1.70-7.85) for forest walking at least once a week and 2.12 for greenspace walking (95% CI â€‹= â€‹1.54-2.92) at least once a week. Conclusions: Our findings suggested that forest/greenspace walking may enhance workers' stress-coping skills.

Stratum corneum TARC level is a new indicator of lesional skin inflammation in atopic dermatitis.

BACKGROUND: Management of atopic dermatitis (AD) requires judging the symptoms of local skin lesions and prescribing a suitable treatment. However, no method has been established in which objective measures can be used to evaluate the severity of local symptoms. We established a method for measuring thymus and activation-regulated chemokine (TARC) levels in the stratum corneum (scTARC), and examined whether the scTARC can be used as an indicator of the severity of local skin lesions in patients with AD. METHODS: Stratum corneum was obtained from patients with AD by tape-stripping, and scTARC was evaluated using a TARC-specific antibody followed by image analysis. The scTARC was examined to determine correlation with the severity of local skin lesions (the severity of erythema, edema/papule, oozing/crusts, excoriations, lichenification, and xerosis) as well as with the severity scoring of atopic dermatitis (SCORAD) index, serum TARC level, serum IgE level, serum lactate dehydrogenase (LDH) level, interleukin (IL)-4-producing T cell ratio (Th2 cell ratio), and blood eosinophil count. RESULTS: The scTARC was correlated with the severity of local skin lesions, especially with the erythema, edema/papule, and oozing/crusts score. The scTARC in the most severe lesions was also correlated with the SCORAD index, serum TARC level, serum IgE level, and blood eosinophil count. The scTARC was not, however, correlated with the serum LDH level and Th2 cell ratio. CONCLUSION: An immunofluorescent technique combined with tape-stripping was used to measure scTARC. The scTARC can be used as an indicator of the severity of local acute inflammation in patients with AD.

Sensitivity and specificity of recombinant omega-5 gliadin-specific IgE measurement for the diagnosis of wheat-dependent exercise-induced anaphylaxis.

BACKGROUND: A recent study has shown that the measurement of specific IgE antibodies to B-cell epitope peptides of wheat omega-5 gliadin (Pep A) and high molecular weight glutenin subunit (Pep B) are useful to diagnose wheat-dependent exercise-induced anaphylaxis (WDEIA). AIMS OF THE STUDY: We sought to compare the sensitivity and specificity of the in vitro tests for measuring the specific IgE antibodies to recombinant omega-5 gliadin (romega-5 gliadin) with those for wheat, gluten, Pep A, and Pep B in identification of patients with WDEIA. METHODS: Fifty patients with WDEIA, 25 healthy subjects and 25 patients with atopic dermatitis with specific IgE antibodies to wheat but without experience of allergic reactions after ingestion of wheat products were enrolled in this study. The concentrations of specific IgE antibodies were measured using ImmunoCAP. The empirical receiver operating characteristics curves (ROC) for each test were prepared and the areas under the ROC curve (AUC) were compared. RESULTS: In patients with WDEIA, the sensitivities of the allergen-specific IgE tests for wheat, gluten, Pep A, Pep B and romega-5 gliadin were 48%, 56%, 76%, 22%, and 80%, respectively. The seven of 10 WDEIA patients with no specific IgE antibodies to romega-5 gliadin had specific IgE antibodies to Pep B. The highest AUC (0.850) was observed in the test for romega-5 gliadin. CONCLUSIONS: Measuring the concentration of specific IgE antibodies to romega-5 gliadin is more useful than to wheat, gluten, or Pep A in the identification of patients with WDEIA.

IgE antibodies to omega-5 gliadin associate with immediate symptoms on oral wheat challenge in Japanese children.

BACKGROUND: Gliadins have been implicated in immunoglobulin E (IgE)-mediated allergy to ingested wheat and omega-5-gliadin is known to represent a major allergen in wheat-dependent exercise-induced anaphylaxis. Less known is whether omega-5-gliadin is a clinically relevant allergen in children with immediate allergy to ingested wheat. This study investigates whether specific IgE antibodies to omega-5-gliadin (sIgE-omega-5-gliadin-ab) could be used as a marker for oral wheat challenge outcome in wheat-sensitized children. A secondary objective was to study whether the level of sIgE-omega-5-gliadin was related to symptom severity in children with a positive challenge test. METHODS: Serum samples from 88 children sensitized to wheat, of whom 35 underwent wheat challenge, were collected consecutively. sIgE-omega-5-gliadin-ab was related to a physician's diagnosis of wheat allergy and challenge symptoms. RESULTS: The mean concentration of sIgE-omega-5-gliadin-ab was 7.25 kU(A)/l in patients with wheat allergy and 1.08 kU(A)/l in patients with no wheat allergy (P < 0.01). sIgE-omega-5-gliadin-ab was only detected in 12 of the non-wheat allergic children and 11 of them had a specific IgE to wheat below 1.30 kU(A)/l. Children reacting with severe symptoms upon challenge (n = 8) had increased levels of sIgE-omega-5-gliadin-ab compared to children with moderate, mild or no symptoms (P < 0.001). CONCLUSIONS: The presence of sIgE-omega-5-gliadin-ab is related to the reaction level to wheat challenge outcome in wheat-sensitized children. The sIgE-omega-5-gliadin-ab was found to be associated with a strong convincing history of wheat allergy also in those cases when oral food challenge was avoided. The sIgE-omega-5-gliadin-ab level may serve as a marker for clinical reactivity in wheat-sensitized individuals.

Regulation of gastric emptying in humans by cholecystokinin.

In the present study we used a bioassay system for measuring plasma cholecystokinin (CCK) to evaluate whether CCK has a physiologic role in regulating gastric emptying in humans. Plasma CCK levels and gastric emptying after ingestion of a mixed liquid meal were determined in five normal male volunteers. Fasting CCK levels averaged 0.8 +/- 0.1 pM and increased to 6.5 +/- 1.0 pM within 10 min of drinking the mixed meal. CCK levels remained elevated for up to 90 min. Gastric emptying after a meal was slow; at the end of the 90 min 68% of the original volume remained in the stomach. The rate of gastric emptying of water was then measured in the same individuals with a simultaneous infusion of either saline, or one of two doses of CCK (12 pmol/kg per h and 24 pmol/kg per h). With the saline infusion, plasma CCK levels did not increase above basal and gastric contents emptied rapidly. At the end of 90 min only 7% of the original volume remained in the stomach. The lower dose of CCK resulted in a plasma level of 3.4 pM which both reproduced the average postprandial plasma level and caused a significant delay in gastric emptying. The higher dose of CCK achieved plasma levels of 8 pM and resulted in a delay in gastric emptying that was similar to that seen with the mixed meal. Since exogenous CCK at concentrations which occur postprandially delays gastric emptying, we conclude that CCK is a physiologic regulator of gastric emptying.

Physiological role for cholecystokinin in reducing postprandial hyperglycemia in humans.

It is known that the ingestion of glucose alone causes a greater increase in plasma glucose levels than ingestion of the same amount of glucose given with other nutrients. Since physiological plasma concentrations of cholecystokinin (CCK) prolong gastric emptying, it is proposed that after a meal, CCK may modify plasma glucose levels by delaying glucose delivery to the duodenum. To evaluate the effect of CCK on oral glucose tolerance, plasma CCK, insulin, and glucose levels and gastric emptying rates were measured in eight normal males before and after the ingestion of 60 g glucose with the simultaneous infusion of either saline or one of two doses of CCK-8 (12 or 24 pmol/kg per h). Gastric emptying rates were measured by gamma camera scintigraphy of technetium 99m sulfur colloid and plasma CCK levels were measured by a sensitive and specific bioassay. Basal CCK levels averaged 1.0 +/- 0.1 pM (mean +/- SEM, n = 8) and increased to 7.1 +/- 1.1 pM after a mixed liquid meal. After glucose ingestion, but without CCK infusion, CCK levels did not change from basal, and the gastric emptying t1/2 was 68 +/- 3 min. Plasma glucose levels increased from basal levels of 91 +/- 3.9 mg/dl to peak levels of 162 +/- 11 mg/dl and insulin levels increased from 10.7 +/- 1.8 microU/ml to peak levels of 58 +/- 11 microU/ml. After glucose ingestion, with CCK infused at 24 pmol/kg per h, plasma CCK levels increased to 8 pM and the gastric emptying t1/2 increased to 148 +/- 16 min. In concert with this delay in gastric emptying, peak glucose levels rose to only 129 +/- 17 mg% and peak insulin levels rose to only 24.2 +/- 4.2 microU/ml. With CCK at 12 pmol/kg per h, similar but less dramatic changes were seen. To demonstrate that endogenous CCK could modify the plasma glucose and insulin responses to oral glucose, oral glucose was given with 50 g of lipid containing long-chain triglycerides. This lipid increased peak CCK levels to 3.7 +/- 0.9 pM. Concomitant with this rise in CCK was a delay in gastric emptying and a lowering of plasma glucose and insulin values. To confirm that CCK reduced hyperglycemia by its effect on gastric motility, 36 g glucose was perfused directly into the duodenum through a nasal-duodenal feeding tube in four subjects. With duodenal perfusion of glucose, there was no change in plasma CCK levels, but plasma glucose levels increased from basal levels of 93+/-5 to 148+/-6 mg/dl and insulin levels rose from 10.6+/-3.5 to 29.5+/-5.2 microU/ml. When CCK was infused at 24 pmol/kg per h, neither the plasma glucose nor insulin responses to the duodenal administration of glucose were modified. Thus we conclude that CCK, in physiological concentrations, delays gastric emptying, slows the delivery of glucose to the duodenum, and reduces postprandial hyperglycemia. These data indicate, therefore, that CCK has a significant role in regulating glucose homeostasis in human.

Effects of a novel cholecystokinin (CCK) receptor antagonist, MK-329, on gallbladder contraction and gastric emptying in humans. Implications for the physiology of CCK.

To explore the physiology of cholecystokinin (CCK) in humans, we investigated the effect on gallbladder contraction and gastric emptying of a recently developed CCK receptor antagonist, MK-329. In a double-blind, four-period crossover study eight subjects received single doses of 0.5, 2, or 10 mg MK-329, or placebo, followed by an intravenous infusion of CCK-8 (30 pmol/kg.h). In placebo-treated subjects gallbladder volumes decreased on average to 43% of initial volumes after 2 h of CCK infusion. MK-329 caused a dose-dependent inhibition of CCK-stimulated gallbladder contraction with 10 mg producing complete blockade (P less than 0.01, cf. placebo). Gallbladder contraction and gastric emptying rates after a mixed meal were then measured in a two-period crossover study. Subjects received placebo or 10 mg of MK-329 2 h before eating. Gastric emptying of both solids and liquids was measured simultaneously by gamma scintigraphy. In placebo-treated subjects plasma CCK levels increased postprandially to 2.3 pM, gallbladder volumes decreased 68.4 +/- 3.8% (SE), and the times for 50% emptying of liquids and solids from the stomach were 58 +/- 10 and 128 +/- 8 min, respectively. In MK-329-treated subjects there was a marked elevation in peak CCK levels to 13.8 pM (P less than 0.01, cf. placebo), and gallbladder contraction was completely inhibited. Solid and liquid emptying rates were unaffected. These findings demonstrate that (a) MK-329 is a potent, orally active antagonist of CCK in humans, and (b) CCK is the major regulator of postprandial gallbladder contraction. These data also support the concept of negative feedback regulation of CCK secretion and suggest that mechanisms other than CCK play a dominant role in the regulation of postprandial gastric emptying rates.

Characterization of the human granulocyte-macrophage colony-stimulating factor promoter region by genetic analysis: correlation with DNase I footprinting.

T-cell activation induces expression of the hematopoietic growth factor granulocyte-macrophage colony-stimulating factor (GM-CSF). To define the molecular events involved in the induction of GM-CSF gene expression more clearly, we prepared and analyzed deletion mutants of GM-CSF promoter recombinant constructs. The results localized inducible expression to a 90-base-pair region (-53 to +37) which is active in uninfected and human T-cell leukemia virus-infected T-cell lines but not in resting or mitogen-stimulated B cells. DNase I footprinting experiments revealed protection of sequences contained within this region, including a repeated nucleotide sequence, CATT(A/T), which could serve as a core recognition sequence for a cellular transcription factor. Upstream of these GM-CSF promoter sequences is a 15-base-pair region (-193 to -179) which has negative regulatory activity in human T-cell leukemia virus-infected T cells. These studies revealed a complex pattern of regulation of GM-CSF expression in T cells; positive and negative regulatory sequences may play critical roles in controlling the expression of this potent granulopoietin in the bone marrow microenvironment and in localized inflammatory responses.

A study on coronary hemodynamics during acetylcholine-induced coronary spasm in patients with variant angina: endothelium-dependent dilation in the resistance vessels.

The epicardial coronary artery of patients with variant angina is hyperreactive to the constrictive effect of acetylcholine, but it is not known whether the coronary microvasculature also constricts in response to acetylcholine. Incremental doses of acetylcholine were injected into the left coronary artery of 57 patients with variant angina and with spasm in this artery. By measuring coronary sinus blood flow, coronary hemodynamic status just before angiographic documentation of spasm was examined. Acetylcholine induced spasm in the left coronary artery in all patients. It also decreased the diameter of the nonspasm artery by 36 +/- 19% from baseline. For all patients, coronary sinus blood flow was 89 +/- 38 ml/min at baseline and increased to 104 +/- 61 ml/min during an acetylcholine-induced anginal attack (p less than 0.01). In 10 patients with spasm in both the left anterior descending and left circumflex arteries (that is, multivessel spasm), coronary sinus blood flow decreased from 84 +/- 21 to 52 +/- 26 ml/min (p less than 0.01). In the other 47 patients with spasm in only one of these two arteries (that is, single-vessel spasm), coronary sinus blood flow increased from 90 +/- 41 to 115 +/- 61 ml/min (p less than 0.01) without change in the rate-pressure product. It is concluded that in patients with variant angina, acetylcholine induces spasm and constriction in the epicardial coronary artery, whereas it dilates the resistance vessels presumably through the release of the endothelium-dependent relaxing factor.

Role of adenosine in pathogenesis of syndrome X: assessment with coronary hemodynamic measurements and thallium-201 myocardial single-photon emission computed tomography.

OBJECTIVES: This study was performed 1) to examine the role of adenosine in the pathogenesis of syndrome X in patients with this syndrome and abnormal results on myocardial scintigrams during exercise, and 2) to determine the susceptibility to myocardial ischemia in this subset of patients with syndrome X. BACKGROUND: A role for adenosine in the pathogenesis of syndrome X has recently been postulated, but there are few clinical data supporting this hypothesis. METHODS: Exercise thallium-201 myocardial scintigraphy after intravenous administration of aminophylline, an adenosine receptor blocking agent, or saline solution and adenosine thallium-201 scintigraphy were performed in 26 patients with syndrome X. Hemodynamic variables during exercise and perfusion defect size after aminophylline and saline infusions were compared. At cardiac catheterization, coronary hemodynamic variables during separate infusions of adenosine and doubutamine were also examined and were compared among patients with abnormal or normal scintigrams and 10 control subjects. RESULTS: Perfusion abnormalities on exercise-thallium-201 scintigraphy occurred in 14 of 26 patients with syndrome X. Intravenous infusion of aminophylline suppressed the scintigraphic perfusion defect and prolonged the time to 1-mm ST segment depression in patients with syndrome X with abnormal exercise scintigrams. Intravenous infusion of adenosine induced a perfusion defect in the same myocardial area where the perfusion defect was observed at exercise in 7 of the 14 patients with syndrome X. At cardiac catheterization, patients with syndrome X with abnormal exercise scintigrams had lower coronary flow reserve and a greater frequency of myocardial lactate production and ST segment depression in response to the infusions of adenosine and doubtamine than did the other two groups. During adenosine infusion, great cardiac vein blood flow and oxygen content were significantly increased and myocardial oxygen consumption and lactate extraction were significantly reduced from baseline without a significant increase in rate-pressure product in this subset of patients with syndrome X. CONCLUSIONS: Patients with syndrome X with abnormal exercise scintigrams have high susceptibility to myocardial ischemia during exercise or pharmacologic stress tests, probably owing to reduced coronary flow reserve. A heterogeneous response to endogenous adenosine may contribute to scintigraphic perfusion abnormalities and myocardial ischemia during exercise in this subset of patients with syndrome X.

Comparison of secretion pattern between A-type and B-type natriuretic peptides in patients with old myocardial infarction.

OBJECTIVES: The present study was designed to compare the secretion patterns of two cardiac hormones--A-type (atrial) and B-type (brain) natriuretic peptides--from the ventricles in patients with old myocardial infarction. BACKGROUND: Plasma levels of these two natriuretic peptides are increased, and their secretion from the ventricles is augmented, in patients with congestive heart failure. METHODS: We measured the plasma levels of these two types of natriuretic peptides at the aortic root and the anterior interventricular vein in 42 patients with old myocardial infarction (anterior in 22 and inferior in 20) and 18 control subjects. RESULTS: The difference between the plasma levels of both A- and B-type natriuretic peptide in the anterior interventricular vein and aortic root was significantly greater in the groups with anterior and inferior infarction than in the control group (A-type [mean +/- SD] 380 +/- 290 and 247 +/- 205 pg/ml in the infarction groups vs. 11 +/- 14 pg/ml; B-type 497 +/- 445 and 75 +/- 73 pg/ml vs. 23 +/- 16 pg/ml, respectively). The difference between the plasma levels of each peptide at the anterior interventricular vein and aortic root had a significant negative linear correlation with left ventricular ejection fraction in both groups with infarction. The slope of the regression line of the arteriovenous difference of B-type natriuretic peptide at the anterior interventricular vein was significantly steeper in the anterior than in the inferior infarction group (left ventricular ejection fraction -12.801 vs. -1.891, p < 0.01). CONCLUSIONS: These results indicate that 1) the secretion of A- and B-type natriuretic peptide from the left ventricular increases in proportion to the severity of left ventricular dysfunction, and 2) secretion of B-type natriuretic peptide is much greater from the infarct than from the noninfarct region, suggesting that the regional ventricular wall stretch caused by infarction strongly stimulates secretion of B-type natriuretic peptide.