Predictive role of circulatory levels of high-mobility group box 1 for radiation pneumonitis in patients with non-small cell lung cancer treated with definitive thoracic radiotherapy

BACKGROUND

High-mobility group box 1 (HMGB1) is a pro-inflammatory protein associated with the pathophysiology of lung injury and lung tumorigenesis. Here, we investigated the predictive potential of serum HMGB1 levels for radiation pneumonitis in patients with lung cancer.

METHODS

This was a retrospective biomarker study of 73 patients with non-small cell lung cancer treated with definitive thoracic radiotherapy between August 2007 and January 2021. We measured HMGB1 levels in serum stored before treatment, and analyzed its association with the development of grade ≥ 2 or grade ≥ 3 radiation pneumonitis. Additionally, baseline characteristics affecting HMGB1 levels were identified.

RESULTS

Of the 73 patients, 21 (28.8%) and 6 (8.2%) patients experienced grade 2 and ≥ 3 radiation pneumonitis, respectively. Univariate and multivariate logistic regression analyses revealed that higher baseline levels of serum HMGB1 were significantly associated with a higher risk of grade ≥ 3, but not grade ≥ 2, radiation pneumonitis. The incidence of grade ≥ 3 radiation pneumonitis was higher in patients with HMGB1 levels ≥ 6.2 ng/mL than in those with levels < 6.2 ng/mL (25.0% vs. 3.5%, p = 0.019). Baseline serum levels of HMGB1 were independently and positively associated with gross tumor volume.

CONCLUSIONS

Higher serum HMGB1 levels were significantly associated with the risk of grade ≥ 3 radiation pneumonitis in patients with lung cancer, and therefore, HMGB1 could be a potential blood biomarker for predicting severe radiation pneumonitis.

Switching Treatment from Mepolizumab to Benralizumab for Elderly Patients with Severe Eosinophilic Asthma: A Retrospective Observational Study

Objective Switching from mepolizumab to benralizumab has been reported to significantly improve both asthma control and the lung function. However, the data on its efficacy in elderly patients with severe eosinophilic asthma are limited. This study aimed to assess whether elderly patients with severe eosinophilic asthma could experience an improved asthma control and lung function when switching directly from mepolizumab to benralizumab. Methods In this single-center, retrospective study conducted between February 2017 and September 2018, we assessed the effect of switching the treatment directly from mepolizumab to benralizumab on eosinophil levels, exacerbation rates, and lung function. We compared the treatment responses between the two groups using either Fisher's exact test or Mann-Whitney U-test, as appropriate. Patients We enrolled 12 elderly patients (age ≥65 years) with severe eosinophilic asthma treated with mepolizumab at Hiroshima Prefectural Hospital (Hiroshima, Japan) during the study period. Six patients were switched from mepolizumab to benralizumab, and six continued with the mepolizumab treatment. Results The switch from mepolizumab to benralizumab caused a near-complete reduction in the eosinophil count (p=0.008). The annual rate of clinically relevant exacerbations and hospitalizations diminished as well, albeit with no statistical significance. We found no improvement in the lung function after switching treatment and no difference in the treatment response between the groups. Conclusion Although this study is based on a small sample of participants, the results indicate that both mepolizumab treatment and switching from mepolizumab to benralizumab treatment without a washout period have clinically relevant asthma control benefits for elderly patients with severe eosinophilic asthma.

Phase 2 study of first-line pembrolizumab in elderly patients with non-small cell lung cancer expressing high PD-L1

e21156

Background: Pembrolizumab is the recommended first-line therapy for patients with advanced non-small cell lung cancer (NSCLC) and a programmed death ligand-1 (PD-L1) tumor proportion score (TPS) of ≥50% without driver mutations. However, its efficacy and safety for patients ≥75 years has not been prospectively investigated; this was the aim of this study. Methods: This multi-center and open-label single-arm phase II study was conducted at 12 institutions. Chemotherapy-naïve patients with advanced NSCLC and a PD-L1 TPS of ≥50% without EGFR mutations or translocation of the ALK received pembrolizumab (200 mg) every 3 weeks. The primary endpoint was progression-free survival (PFS) with a threshold of 4.3 months. The secondary endpoints were overall survival (OS), objective response rate (ORR), disease control rate (DCR), safety. Quality of life (QOL) was assessed using EORTC QLQ-C30 and EORTC QLQ-LC13. The patients completed the questionnaires immediately after providing informed consent, and also before the third, sixth, twelfth, eighteenth, and twenty-fourth treatment cycles. Results: Twenty-six patients were enrolled between October 2017 and March 2020. The median PFS was 9.6 (95% confidence interval [CI], 2.1–20.6) months. The lower limit of the 95% CI did not exceed the target. The median OS was 21.6 (95% CI, 15.1–not reached) months.The ORR and DCR were 41.7% (24.5–61.2) and 70.8% (50.8–85.1), respectively. The proportion of patients with Grade ≥3 treatment-related adverse events was 15.4%. The Score of Global Health Status/QOL, symptom scales and/or items, and functioning scales of EORTC QLQ-C30 and EORTC QLQ-LC13 did not change significantly during the treatment. Conclusions: This study showed pembrolizumab was tolerable treatment for the elderly patients. Although the primary endpoint, the median PFS (9.6 months) was slightly shorter than that (10.3 months) of the previous phase III study (KEYNOTE-024 study), the median PFS, did not achieve the expected value. Clinical trial information: UMIN000040474.

Phase 2 study of first-line pembrolizumab monotherapy in elderly patients with non-small-cell lung cancer expressing high PD-L1

Background

Pembrolizumab is the recommended first‐line therapy for patients with advanced non‐small‐cell lung cancer (NSCLC) and a programmed death ligand‐1 (PD‐L1) tumor proportion score (TPS) of ≥50% without driver mutations. However, its efficacy and safety for patients ≥75 years have not been prospectively investigated; this was the aim of this study.

Methods

This multicenter and open‐label single‐arm phase II study was conducted at 12 institutions. Chemotherapy‐naïve patients with advanced NSCLC and a PD‐L1 TPS of ≥50% without EGFR mutations or translocation of the ALK received pembrolizumab every 3 weeks. The primary endpoint was progression‐free survival (PFS) with a threshold of 4.3 months. The secondary endpoints were overall survival (OS), objective response rate (ORR), disease control rate (DCR), safety, and quality of life.

Results

Twenty‐six patients were enrolled between October 2017 and March 2020. The median PFS was 9.6 (95% confidence interval [CI] 2.1–20.6) months. The lower limit of the 95% CI did not exceed the target. The median OS was 21.6 months. The ORR and DCR were 41.7% and 70.8%, respectively. The proportion of patients with grade ≥3 treatment‐related adverse events was 15.4%. The quality of life score did not change significantly during treatment.

Conclusion

While this study showed that pembrolizumab was a tolerable treatment for elderly patients, the safety requires further confirmation in a larger study. Although the primary endpoint, the median PFS (9.6 months), was slightly shorter than that (10.3 months) of the previous phase III study (KEYNOTE‐024 study), the median PFS did not achieve the expected value.

Effect of baricitinib in patients with coronavirus disease 2019 and respiratory failure: a propensity score–matched retrospective cohort study

In this retrospective cohort study, we evaluated the efficacy of baricitinib in the treatment of coronavirus disease 2019 (COVID-19). Among 404 adult patients with COVID-19 who were admitted to our hospital between October 23, 2020, and July 31, 2021, 229 patients with respiratory failure were included. Among these, 41 patients in the baricitinib group and 41 patients in the control group were selected by propensity score matching to adjust for background factors. We compared the survival rates of the two groups at 30 and 60 days after admission. The 30-day survival rate was significantly higher in the baricitinib group than in the control group. However, there was no significant difference in 60-day survival in the two groups. Baricitinib may improve the early prognosis of patients with respiratory failure associated with COVID-19. However, efforts should be made to improve the long-term prognosis.

Efficacy of mepolizumab in elderly patients with severe asthma and overlapping COPD in real-world settings: A retrospective observational study

BACKGROUND

Asthma and chronic obstructive pulmonary disease (COPD) are the most common respiratory diseases, presenting overlapping prevalence with age. Mepolizumab is a humanized monoclonal antibody targeting interleukin-5. In major randomized clinical trials, this antibody reportedly reduced the circulating eosinophil count, exacerbation rate, and oral corticosteroid (OCS) dosage in patients with severe eosinophilic asthma. However, data regarding the efficacy of mepolizumab in elderly patients with asthma and overlapping COPD are limited.

METHODS

This was a single-center, retrospective, observational study. Elderly patients (age ≥65 years) administered mepolizumab between August 2016 and March 2019 were enrolled and the effects of mepolizumab on the eosinophil level, exacerbation numbers, OCS dosage, and lung functions were assessed. We compared treatment responses in patients with asthma and COPD overlap (ACO) with responses observed in patients with severe asthma alone. Adverse events were also evaluated.

RESULTS

Twenty patients (10 men and 10 women), with a mean age of 77.5 ± 1.3 years, were included. Mepolizumab significantly reduced the blood eosinophil count, as well as significantly decreased clinically significant exacerbation, in both populations. The OCS dosage was significantly reduced in patients treated receiving maintenance OCS therapy. However, mepolizumab did not improve lung function in either population, and no significant difference was observed in treatment responses between patients with asthma alone and ACO.

CONCLUSIONS

Mepolizumab may be effective in elderly patients with eosinophilic asthma and ACO.

First-line immune checkpoint therapy in metastatic squamous cell lung cancer harboring both EGFR mutation and high expression of PD-L1: A case report

A 90-year-old female was admitted to our hospital with a history of a dry cough. Chest computed tomography (CT) scan showed a tumor shadow, and CT-guided lung biopsy revealed squamous cell carcinoma harboring an EGFR mutation. In addition, programmed death-ligand 1 (PD-L1) was highly expressed with a tumor proportion score (TPS) of >75%. Pembrolizumab therapy in the first-line setting was not effective, and the patient died at six months from the first visit. Squamous cell lung cancers (SCLCs) with both EGFR mutation and high expression of PD-L1 are very rare.

[A Case of Small Cell Lung Cancer Diagnosed with Metastasis-Induced Acute Pancreatitis]

A 56-year-old man was admitted to our hospital for management of acute epigastric abdominal pain and elevation of pancreatic enzymes. The CT scan revealed enlargement ofthe pancreatic body as well as the lung tumor ofthe right hilar and superior mediastinum. Therefore, bronchoscopy was performed and a diagnosis of small cell lung cancer with metastasisinduced acute pancreatitis(MIAP)was made. Prompt improvement in pancreatic findings was observed following chemotherapy. MIAP, which is a rare complication of lung cancer may affect the prognosis and quality of life of the patients; therefore, rapid diagnosis and appropriate treatment are important.

Percutaneous ulnar artery approach for coronary angiography: a preliminary report in nine patients

The radial artery approach is becoming more popular for diagnostic cardiac catheterization and interventional procedures because of its lower incidence of access site complications and decreased patient discomfort after the procedure. However, Allen's test reveals inadequate blood supply through the ulnar artery to the hand, and therefore the approach does not seem to be suitable in 10%-30% of patients. Here we demonstrated a new percutaneous ulnar artery approach for coronary angiography in nine patients. We succeeded in obtaining an entry site into the left ulnar artery in seven patients. The average time for cannulation and that for catheterization procedure were comparable with those of the radial approach previously reported from other laboratories. Complications such as bleeding, loss of an ulnar pulse, ulnar nerve injury, and the formation of an aneurysm or fistula were not observed in any patient. The ulnar approach may be another technique that decreases patient discomfort and risk, while preserving the radial artery as a potential coronary bypass graft for surgical myocardial revascularization. Cathet Cardiovasc Intervent 2001;53:410-414.

Altered ischemic induction of immediate early gene and heat shock protein 70 mRNAs after preconditioning in rat hearts

Immediate early genes and heat shock protein (HSP) 70s, which may play a role in adaptation and cellular protection, respectively, are induced by ischemia in hearts. We examined if the induction of immediate early gene (c-fos, c-myc, c-jun, and junB) and HSP70 mRNAs by ischemia is affected by ischemic preconditioning. Transient ischemia (5 or 10 minute) was applied to Wistar rat (n=75) hearts, by tightening a snare placed around left coronary arterial branches 7 days before applying ischemia. Rats without earlier ischemia (control group, C) and rats with 5-minute ischemia 12 or 24 hours earlier (EI12 or 24 group) were given 10-minute ischemia and sacrificed at 0, 0.5, 1, 2, and 4 hour. RNA was extracted from the ischemic region and Northern blot analysis was performed. The induction of c-fos and c-myc mRNAs was significantly increased in EI12 but not in EI24 compared with that in C. The induction of c-jun and junB mRNAs showed no change in both EI12 and EI24 compared with that in C. The induction of HSP72 and 73 mRNAs was decreased in EI12 and decreased further in EI24. Thus, ischemic preconditioning altered the induction of immediate early gene and HSP70 mRNAs by ischemia. The effect of preconditioning differed among genes studied and changed with time after preconditioning. Ischemic preconditioning alters protective and adaptive responses to ischemia at the gene level.

Arg506Gln mutation of the coagulation factor V gene not detected in Japanese pulmonary thromboembolism

The incidence of pulmonary thromboembolism (PTE) is lower in Japanese than in Caucasians. The basis for the different incidence has not been clarified. A poor anticoagulant response to activated protein C based on a single point mutation of the factor V gene (Arg506Gln) was found to be a pathogenetic factor for venous thrombosis and PTE in North America and Europe. We investigated whether the Arg506Gln mutation of factor V is responsible for the occurrence of PTE among Japanese. We analyzed genomic DNA prepared from fresh peripheral blood of 25 patients with PTE of unknown etiology (12 of acute type and 13 of chronic type) and that of 110 controls without respiratory or circulatory disorders. To detect the Arg506Gln mutation, 267 bp DNA fragments of the factor V gene including the Arg506Gln region were amplified by PCR, digested by MnlI and electrophoresed. After digestion of PCR products with MnlI, DNA fragments of 163 bp length, but not DNA fragments of 200 bp length, were identified in all samples, indicating the absence of the Arg506Gln mutation in the patients with PTE and control subjects. These results suggest that the Arg506Gln mutation is absent or very rare and not an important pathogenetic factor for PTE in Japanese.

Differential expression of alpha 1, alpha 3 and alpha 5 integrin subunits in acute and chronic stages of myocardial infarction in rats

OBJECTIVE

Anchoring cardiac myocytes to extracellular matrix, which is mediated mainly by integrins on their surfaces, is important for maintaining the architecture of myocardial tissues and transmitting mechanical force. We evaluated the expression of alpha integrin subunits on myocytes and the accumulation of interstitial collagen and fibronectin at acute and chronic stages after myocardial infarction.

METHODS

Myocardial infarction was induced by ligation of left coronary arteries in rats. The expression of alpha 1, alpha 3 and alpha 5 integrin subunits, and accumulation of collagen and fibronectin were analyzed with immunohistochemistry or sirius-red staining.

RESULTS

In hearts without infarction, moderate expression of the alpha 3 subunit and only slight expression of the alpha 5 subunit were observed on myocytes. In the first week after infarction, the alpha 1 subunit, collagen and fibronectin were increased only in the peri-infarcted area, while the alpha 5 subunit was increased both in peri-infarcted and non-infarcted areas. At day 42, the expression of the alpha 1 subunit and collagen were still increased, although the alpha 5 subunit and fibronectin were decreased. The expression of the alpha 3 subunit was not altered throughout the experimental period.

CONCLUSION

These data suggest that integrin subunits play an important role in healing and remodeling processes after myocardial infarction.

The role of alcohol dehydrogenase 2 and aldehyde dehydrogenase 2 genotypes in alcohol-induced vasospastic angina

Alcohol ingestion often provokes attacks in patients with vasospastic angina. Type 2 aldehyde dehydrogenase (ALDH2) deficiency, which is based on a single point mutation (Glu487Lys) of the ALDH2 gene, is common in the Japanese population, but rare among the Caucasian population. We investigated how the genotype of ALDH2 affects the characteristics of alcohol-induced vasospastic angina. Ninety-one patients with vasospastic angina who had ingested alcohol daily or occasionally were studied. Patients had been diagnosed as vasospastic angina by a provocation test with an intracoronary injection of ergonovine or acetylcholine during coronary angiography. The Glu487Lys mutation was detected by allele specific PCR. We interviewed the patients to obtain information concerning the relationship between alcohol ingestion and anginal attacks. Alcohol ingestion induced attacks in 16 of 66 patients without the Glu487Lys mutation, 8 of 22 in heterozygotes, and 1 of 3 in mutant homozygotes. The intervals between alcohol ingestion and the onset of anginal attacks were shorter in homozygotes (0.17 hours) and heterozygotes (1.5+/-0.6 hours) for ALDH2*2 than in normal homozygotes for ALDH2*1 (5.4+/-0.6 hours). The amount of ethanol which induced attacks was significantly greater in normal homozygotes than in homozygotes (11 ml) and heterozygotes (42.5+/-7.1 ml) for ALDH2*2 (96.1+/-13.4 ml in normal patients). The frequency of anginal attacks induced by alcohol ingestion did not differ between ALDH deficient and normal homozygotes. In ALDH deficient patients, however, anginal attacks were induced by a smaller amount of alcohol immediately after its ingestion. Thus, the ALDH2 genotype modifies the characteristics of the anginal attacks as a co-factor for the induction of vasospastic angina after alcohol ingestion.

Vessel size-dependent expression of intermediate-sized filaments, calponin, and h-caldesmon in smooth muscle cells of human coronary arteries

The arterial media is composed of a heterogeneous population of smooth muscle cells (SMCs). Recently, the properties of SMCs were observed to be heterogeneous not only among individual cells but also among arteries of the same vascular bed. To test the hypothesis that a site-specific heterogeneity exists in the SMCs of human coronary arteries, we examined the expression of desmin, vimentin, calponin, and high-molecular-weight (h-) caldesmon in arteries of various sizes. Specimens of arteries were obtained at autopsy from 12 patients: 6 adults (67 +/- 4 years old); 3 younger adults (26 +/- 2 years old); and 3 neonates. The size of the arteries was estimated by the number of SMC layers of the media. The expression was compared in SMCs of large arteries (>10 layers in adults, >5 layers in neonates), medium-sized arteries (5-10 layers in adults, 3-5 SMC layers in neonates), and small arteries (<3 layers). In adults, the percentage of arteries positive for desmin was lower in the small (17% +/- 3%) and medium-sized arteries (44% +/- 12%) than in the large arteries (94% +/- 6%) (P < 0.01). The percentage of arteries positive for calponin was also lower in the small (18% +/- 2%) and medium-sized arteries (66% +/- 5%) than in the large arteries (100%) (P < 0.01). The percentage for vimentin and h-caldesmon did not differ among large, medium-sized, and small arteries. These observations in adults were similar to those in younger adults or neonates. The phenotypes of medial SMCs are vessel size-dependent in human coronary arteries. This finding should be important for understanding the site-specific characteristics of vascular function in the regulation of myocardial perfusion or those of vascular responses to environmental changes.

Heterogeneous smooth muscle cell population derived from small and larger arteries

Vascular lesion formations in such disease states as hypertension and atherosclerosis occur in a district-specific manner. Large conduit and small resistance arteries play district-specific roles in the regulation of organ perfusion. Using a culture method, we studied the morphology and growth of smooth muscle cells derived from small arteries (S-SMCs, less than 90 microm in internal diameter) and from larger arteries (L-SMCs, ranging from 800 to 900 microm) of the rat mesenteric arterial bed. S-SMCs showed a hill-and-valley pattern, whereas L-SMCs showed sheet or whorl formation. The majority of S-SMCs were smaller, bipolar-shaped; in contrast, the majority of L-SMCs were larger, polygonal-shaped. Actin fibers within S-SMCs were oriented in a bipolar manner from the nuclei, whereas those within L-SMCs had a radial appearance. [3H]Thymidine incorporation induced by serum, platelet-derived growth factor-AB (PDGF), or mechanical stretch was greater in S- vs L-SMCs. The population doubling time measured after the addition of serum or PDGF was shorter in S- vs L-SMCs. Thus, distinct morphological and growth phenotypes of SMCs exist in small and larger arteries of the same vascular bed.

Heat shock protein expression in hearts hypertrophied by genetic and nongenetic hypertension

Genetically hypertensive animals are characterized by greater thermosensitivity and overexpression of heat shock proteins (HSP) upon thermal stimulation. We examined HSP72 expression under conditions of brief coronary occlusion or thermal stimulation, and the effects of the severity of these stimuli and of myocardial hypertrophy on the expression in hearts of spontaneously hypertensive rat (SHR) and Wistar Kyoto rat (WKY) groups, A snare was created around the left coronary artery in the SHR (n = 16) and WKY (n = 19) groups. In 7 WKY rats, the ascending aorta was banded and a snare was created simultaneously (WKY-AoB). By tying the snare, 4 weeks later, we applied 5- or 10-min coronary occlusion without opening the chest. For thermal stimulation, the SHR (n = 13) and WKY (n = 11) rats were placed in a 42 degrees C chamber for 15 or 40 min. The mRNA or protein level was estimated 1 or 24h after stimulation. In the SHR vs WKY groups, the mRNA and protein levels were higher after 5-min occlusion or 15-min thermal stimulation. After 10-min occlusion or 40-min thermal stimulation the difference was no longer observed. The overexpression was not observed in the WKY-AoB group despite the presence of hypertrophy similar to that seen in the SHR group (3.11+/-0.11 vs 3.20+/-0.06 mg/g in left ventricular weight/body weight). The HSP72 was overexpressed in hearts of genetically hypertensive animals after brief ischemia. Differential expression between the two groups was observed after mild stimuli, but not after more severe stimuli. Cardiac hypertrophy was not a major factor for determining the overexpression of HSP72.

Attenuation of heat shock protein expression by coronary occlusion in hypertrophied hearts

Hearts hypertrophied by pressure-overload are more susceptible to ischemia than nonhypertrophied hearts, which may result from the attenuation of self-protective responses. Because heat shock proteins (HSPs) are reported to protect against ischemic injuries, we hypothesized that HSP expression by coronary occlusion may be attenuated in hypertrophied hearts. We banded the ascending aorta to develop ventricular hypertrophy and put a snare around the left coronary artery in rats. After 4 wk, coronary occlusion was applied by tightening the snare for 5 or 10 min in rats with and without aortic banding. The hearts were excised 0, 0.5, 1, 2, 4, 8, 12, and 24 h after coronary occlusion. Ischemic and nonischemic myocardial tissues were obtained after the snare was tightly tied, and dye was infused from the aorta. The mRNAs and protein of 72-kDa HSP (HSP 72) and/or 73-kDa HSP (HSP 73) were detected by Northern and Western blot analyses. Protein and mRNA levels of HSPs expressed by 5-min coronary occlusion in hypertrophied hearts (left ventricular weight, 577 +/- 16 mg) were lower compared with those in control hearts (462 +/- 9 mg). A longer period of coronary occlusion (10 min) elevated the attenuated expression to a level similar to that in control hearts. Treatment with an angiotensin-converting enzyme (ACE) inhibitor (cilazapril, 10-15 mg.kg(-1).day(-1)) for 4 wk preserved HSP mRNA expression even in hearts with ascending aortic banding. In hypertrophied hearts, HSP 72 and 73 expression by coronary occlusion was attenuated and was modulated by the duration of coronary occlusion and by ACE inhibitor treatment.

Eosinophils as a source of matrix metalloproteinase-9 in asthmatic airway inflammation

Bronchial asthma is characterized by eosinophil infiltration and tissue remodeling. Matrix metalloproteinases (MMPs) are thought to play critical roles by degradating interstitial matrices in a wide range of lung diseases associated with reorganization of the airway architecture. To investigate whether MMPs are involved in the pathologic processes of bronchial asthma, we examined MMP expression in asthmatic subjects. In situ hybridization revealed abundant expression of MMP-9 (gelatinase B) mRNA in biopsy specimens from asthmatic subjects (n = 5), with an average positive cell distribution of 117.8 +/- 41.1 (mean +/- SEM)/mm2. In contrast, sparse expression of the mRNA (10.8 +/- 4.8 /mm2) was observed in specimens from normal subjects (n = 4). The vast majority of cells expressing the mRNA were eosinophils in asthmatic tissues (92.2 +/- 1.2%). MMP-9 protein, which was confined to the submucosal cells in the normal subjects, was not abundantly expressed in inflammatory cells, but there was positive reactivity for MMP-9 protein in the extracellular matrix. Immunoelectron microscopic analysis showed sparse immunolocalization of MMP-9 in the perinuclear spaces of eosinophils, but not in the granules. These findings suggest the overexpression of MMP-9 by eosinophils in bronchial tissues of asthmatic individuals, and the participation of MMPs in the pathologic changes in asthmatic airways.

Anti-atherogenicity in women does not prevent restenosis after balloon angioplasty

To test the hypothesis that anti-atherogenicity in women exerts beneficial effects to prevent restenosis formation after coronary angioplasty, we studied 493 men (988 lesions) and 81 women (159 lesions), aged 40-60 years, who had undergone successful balloon angioplasty and had follow-up angiography, 4.9 +/- 4.1 months later. We compared the extent of restenosis between men and women, and between pre- and post-menopausal women, which was assessed by a categorical definition of restenosis (more than 50% diameter stenosis at follow-up) and by percent diameter measured immediately after angioplasty and at follow-up. Hypertension was more frequent in women and a significantly lower percentage of women smoked. In women, the levels of total cholesterol and low-density lipoprotein cholesterol were higher. The location of dilated lesions, frequency of angioplasty for lesions with chronic total occlusion, and frequency of emergency angioplasty in patients with unstable angina or acute myocardial infarction were similar in men and women. Restenosis formation, estimated by the categorical definition or percent diameter, did not differ between men and women, or between pre- and post-menopausal women. Menopausal status or sex was not an independent predictor of restenosis by multivariate analysis. Thus, the benefit of anti-atherogenicity in women does not play an important role in preventing restenosis after coronary angioplasty.

Comparisons of IgE, IgG, and IgG4 responsiveness to Dermatophagoides farinae in children by immunoblotting

Although asthmatic children are often sensitized to the house-dust mite (HDM) during early childhood, it is not clear what antigenic components are associated with the early immune response of these children. To investigate this problem, we evaluated IgE, IgG, and IgG4 antibody responses to Dermatophagoides farinae (Df) by immunoblotting among three groups of children: group I aged 0-4 years, group II aged 5-9 years, and group III aged 10-14 years. In the group I subjects, positive IgE-binding reactions to 15- and 25-kDa components were found in 76% and 44% of sera, respectively. Those to other components were generally low in frequency. In contrast, positive IgG-binding reactions to 15- and 25-kDa components were found in 44% and 24% of sera, and those to 30- and 110-kDa components in 48% and 88% of sera, respectively. Positive IgG4 reactions to 15- and 25-kDa components were found in 48% and 24%, respectively, and those to other components were very low. Positive IgE-binding reactions to these components gradually became more frequent with increasing age in groups II and III, while IgG and IgG4 reactivities were not markedly different in these age groups. These results suggest that the 15- and 25-kDa proteins of Df are important antigens associated with the initial IgE response to HDM in early childhood, while the 30- and 110-kDa proteins are associated with IgG and 15-kDa components with IgG4.

Treatment of whole houses with liquid nitrogen for control of dust mites

A large volume of liquid nitrogen, (120-150 L) was applied to the houses of 4 asthmatic patients, and the mite densities of the floor dust from these houses were monitored every 2 wk for 4 mo from July to November 1989. The 1st liquid nitrogen treatment was applied in early August and decreased the mite densities to 20-44% of the pretreatment level in all cases, but they returned to the pretreatment level 3-4 wk later (on 3 occasions). The 2nd liquid nitrogen treatment was applied in early September and decreased the mite densities to 6-27% of the pretreatment level within 3 wk in all cases. However, mite numbers again increased to the pretreatment level 4 wk after treatment. The 3rd treatment was applied in mid-October and reduced the mite densities to < 6% of the pretreatment level within 2 wk, and mite numbers remained low thereafter. The results suggested that using liquid nitrogen to freeze houses reduces mite numbers, but that mite recolonization of the houses is an important problem.

Age-related changes before and after imposition of hemodynamic stress in the mammalian heart

This review focusses on the following issues: how the mammalian heart grows and ages; age-related changes in the mammalian heart before and after imposition of hemodynamic stress; and antiaging modulation in the mammalian heart. The heart and other organs grow and age together in the whole body, and interactions occur between these organs. Therefore, the age-related changes at the molecular and cellular level in the in vivo heart are the summation of the changes of the heart per se and the effects of other organs or tissues on the heart. Furthermore, myocytes grow and age under the influence of age-related changes in other myocytes and other types of cells in the myocardial tissue through autocrine or paracrine mechanisms, because myocytes are exposed to many biologically active substances which are released from those cells. Since hypertension and ischemia are very common hemodynamic events in aged hearts, the characteristics in aged hearts are discussed in terms of responses to hypertension or ischemia. The induction of proto-oncogenes and heat shock protein genes in response to milder hemodynamic stress such as pressure-overload and ischemia is diminished in aged hearts. However, the aged heart can respond to more severe stress to a level similar to that of young-adult hearts. Therefore, the senescent heart is characterized by its attenuated adaptation to hemodynamic stress and by its ability to adapt to limited environmental changes. Several interventions have antiaging effects on the heart at the molecular and cellular level.

Coronary angioplasty ameliorates hypoperfusion-induced endothelial dysfunction in patients with stable angina pectoris

OBJECTIVES

This study sought to investigate the effect of coronary angioplasty on chronic hypoperfusion-induced endothelial dysfunction in patients with coronary heart disease.

BACKGROUND

The endothelium is an important component for organ flow regulation. Ischemia with or without reperfusion is known to cause endothelial dysfunction. We tested the hypothesis that chronic hypoperfusion impairs endothelial function in the angiographically normal coronary artery segment distal to stenosis and that the impairment by chronic hypoperfusion is reduced by coronary angioplasty.

METHODS

In 13 patients with stable angina pectoris, substance P (10, 30 and 100 pmol) and nitroglycerin (200 micrograms) were sequentially infused into the coronary artery in a cumulative manner on the day after coronary angioplasty. In 10 of these patients, vascular responses to these agents were again investigated 3 months after angioplasty. Changes in vascular diameter were evaluated in vessels located proximal and distal to the target lesion, both of which were angiographically normal, by performing computer-assisted quantitative coronary angiography. In five patients, the transstenotic pressure gradient was also measured with a pressure sensor-mounted guide wire before angioplasty.

RESULTS

On the day after angioplasty, the magnitude of dilation by substance P in distal segments was significantly less than that in proximal segments and inversely correlated with the transstenotic pressure gradient (p < 0.05) and lesion stenosis (p < 0.05). There was no difference in nitroglycerin-induced vasodilation between the two vessel segment groups. Three months later, the impaired response to substance P in the distal segment was restored to normal.

CONCLUSIONS

We conclude that chronic hypoperfusion impairs endothelium-dependent dilation of coronary artery distal to critical stenosis in patients with ischemic heart disease and that coronary angioplasty ameliorates the endothelial dysfunction within 3 months.

Diminished heat shock protein 70 mRNA induction in aged rat hearts after ischemia

Vulnerability of aged hearts to ischemia may be due to defects in protective mechanisms provided by heat shock proteins (HSPs). To determine whether there is a defect in the induction of HSPs by ischemia in old hearts, HSP72 and HSP73 (inducible and constitutive HSP70, respectively) mRNA induction was examined in young (2-mo-old; n = 36) and old (18-mo-old; n = 32) rat hearts. Transient (10- or 20-min) ischemia was applied by tightening a snare placed around left coronary arterial branches 3 days before examination to avoid the effect of operation on induction. HSP72 mRNA was induced markedly in young hearts after 10-min ischemia, peaked at 2 h, but was induced only slightly in old hearts. HSP73 mRNA was also induced in young hearts, peaked at 4 h, but was not induced in old hearts. The mRNAs were markedly induced in old hearts as well after 20-min ischemia, which was accompanied by the induction of HSP72 protein. Thus the age-related modulation of HSP72 and HSP73 mRNAs suggests a defective sensing mechanism for ischemia in old hearts.

Hypertension and age-related changes in the heart. Implications for drug therapy

Heart disease in older individuals can be characterised as the result of 2 processes, hypertension and atherosclerosis, which are the major causes of heart failure in the elderly population. The aging heart undergoes changes at the molecular, cellular and organ levels. These age-related changes may then be modulated by pathological conditions, such as hypertension, and by the reduction of blood pressure. One characteristic of the aged heart is a limited capacity for adaptation, by hypertrophy, to increased mechanical load. This age-related attenuation of the hypertrophic response may be attributed to the diminished induction of proto-oncogenes such as c-fos, c-myc and c-jun. This diminution results from aging of the heart per se and may be modulated by extracardiac factors. With regard to the coronary vasculature, the age at which hypertension develops seems to be an important factor for determining the vascularity of hypertrophied hearts. Late-onset hypertension is not accompanied by coronary angiogenesis, and it decreases dilator reserve in spite of the absence of myocardial hypertrophy. In contrast, mechanical overload in infant hearts is accompanied by angiogenesis and normal dilator reserve. In principle, the normalisation of hypertension results in the regression of myocardial hypertrophy and decreased coronary dilator reserve. In aged hearts, it is not clear how hypertension-induced myocardial hypertrophy or coronary vascular changes regress. Although antihypertensive treatment is clearly associated with an improvement of cardiovascular mortality and morbidity in hypertensive elderly individuals, it remains unclear how treatments ameliorate the hypertension-induced alterations.

Responses to hemodynamic stress in the aged heart

In aged individuals the incidence of heart failure is higher than in younger subjects. Ischemic events are also common in the aged heart because of changes in the coronary vasculature and myocytes caused by aging. Adaptational responses to increased hemodynamic overload and to ischemia in the aged heart are discussed at the molecular, cellular and organ levels. One characteristic of the aged heart is a limited capacity for adaptation with hypertrophy to increased mechanical load. This age-related attenuation of the hypertrophic response may be attributed to the diminished induction of proto-oncogenes such as c-fos, c-myc and c-jun by hemodynamic stress. This diminution results from the aging of the heart per se and may be modulated by extracardiac factors. An age-related diminution was also observed in the mRNA induction of heat shock proteins by transient ischemia. However, this diminished induction of immediate early genes in the aged heart was not observed after more severe stress. With regard to the coronary vasculature, the age at which pressure-overload begins seems to be one of the important factors which determine the vascularity of hypertrophied hearts. Late-onset pressure-overload decreased dilator reserve in spite of the absence of myocardial hypertrophy. Thus, the responses to stress in the aged heart are quite different from those in the young heart. The limited capacity for adaptation to hemodynamic overload and poor protective mechanisms against stress may be causes of the higher incidence of heart failure in the aged.

Effects of aging on induction of cardiocyte growth by extracardiac factors

To examine the effect of aging on the induction of cardiac myocyte growth by extracardiac factors, we cultured myocytes obtained from neonates of the same litter and implanted them into the peritoneal cavity of developmental phase (2-mo-old), young adult (7-mo-old), and aged (18-mo-old) host Wistar rats. Hearts obtained from 2- to 4-day-old neonates were dissociated with gentle trypsinization, and cells were seeded in culture wells and inserts. The culture insert (9 mm in diam) has a thin membrane the pore size of which is 0.45 microns. After 24 h of usual extracorporeal incubation in the serum-supplemented medium, the inserts were implanted into the peritoneal cavity of the host rats of the three age groups. Zero, 24, 72, and 96 h after implantation into the peritoneal cavity, the inserts were removed from the peritoneal cavity. Surface area of plated myocytes, diameter, number, protein, and DNA content of the suspended cells were measured. Size, protein content per cell, and protein per DNA of cells implanted into the peritoneal cavity were significantly greater than those cultured in the usual extracorporeal method. Growth of the myocytes cultured in the peritoneal cavity of aged host rats was significantly less compared with that of myocytes implanted in the peritoneal cavity of younger rats. Thus aging attenuates the induction of cardiac myocyte growth by extracardiac factors.

Crossreactivity of IgE antibody against Dermatophagoides farinae with Limulus polyphemus agglutinin

Crossreactivity of IgE antibody against Dermatophagoides farinae (Der f) with Limulus polyphemus agglutinin (LPA) was examined using RAST and immunoblot analysis. Of 40 Der f-sensitive asthmatic patients, 28 revealed a positive RAST reaction to LPA, while none of 20 Der f-insensitive hay fever patients showed this reaction. LPA-specific RAST levels of the 40 asthmatic patients correlated with their Der f-specific levels. The RAST reactivity to LPA was competitively inhibited by the addition of either soluble Der f or LPA, but not by the specific inhibitory sugar of sialic acid. LPA could also induce histamine release from leucocytes of Der f-sensitive asthmatic patients. IgE immunoblot analyses showed that the positive RAST sera for LPA had a strong IgE binding activity to the 30 kDa and 80 kDa components of Der f body extract, whereas gel filtration studies showed that the high molecular weight fractions above 150 kDa retained antigenic constituents associated with IgE reactivity to LPA. These results suggest that the antigenic materials of Dermatophagoides mites share some determinants with the haemagglutinin of horseshoe crabs.

Acute ischaemic preconditioning and chronic hypoxia independently increase myocardial tolerance to ischaemia

OBJECTIVE

Myocardial adaptation has been reported to result from mild but chronic ischaemia in the hearts of patients with coronary artery disease. The aim of this study was to test the hypothesis that the responses of the chronically hypoxic myocardium to an episode of severe ischaemia, or the effects of acute ischaemic preconditioning on myocardial function after subsequent fatal ischaemia, may differ between the normoxic and the chronically hypoxic myocardium.

METHODS

A rat model of three week hypoxia (10% O2) was used to simulate tissue hypoxia caused by chronic ischaemia. In isolated isovolumetrically contracting hearts perfused with oxygenated erythrocyte-containing Tyrode solution, systolic and diastolic functions during a 15 or 20 min period of ischaemia and reperfusion were measured in the normoxic control and chronically hypoxic groups.

RESULTS

Increases in diastolic pressure during ischaemia were smaller and the recovery of developed pressure during reperfusion was greater in the chronically hypoxic group than in the normoxic group. The hearts of the normoxic group never recovered from ischaemic damage after 20 min ischaemia. The beneficial effects of acute preconditioning with 5 min ischaemia on myocardial function were observed after 15 min ischaemia in the normoxic group, and during and after 20 min ischaemia in the chronically hypoxic group. Changes in lactate production and high energy phosphates could not explain the increased tolerance to ischaemia in the chronically hypoxic group.

CONCLUSIONS

Chronic hypoxia increased myocardial tolerance to ischaemia, and acute ischaemic preconditioning increased the tolerance further. Thus chronic hypoxia and acute ischaemic preconditioning independently activate protective mechanisms against ischaemia; the mechanisms may differ between the two types of insult.

Remodelling of microvessels by coronary hypertension or cardiac hypertrophy in rats

We attempted to clarify the individual effects of coronary hypertension and ventricular pressure-overload on the remodelling of coronary arterial microvessels. We examined structural vascular changes in the right ventricular free walls using two experimental rat models: 12-week ascending aortic banding, i.e. a model of coronary hypertension without ventricular pressure-overload and 12-week pulmonary artery banding, i.e. a model of ventricular pressure-overload without coronary hypertension. In vivo peak systolic left ventricular pressure and left ventricular weight to body weight ratio in the aortic banding model increased to 198 +/- 10 mmHg and by 39% above the controls, respectively. In vivo peak right ventricular pressure and right ventricular weight to body weight ratio in the pulmonary artery banding model increased to 87 +/- 7 mmHg and by 69% above the controls, respectively. The right coronary reserve measured by the Doppler method decreased in both experimental models. Aortic banding increased the medial area and perivascular collagen to lumen area ratios in the microvessels > 30 microns in lumen diameter but not in those < 30 microns. Pulmonary artery banding increased the perivascular collagen to lumen area ratio in the microvessels < 60 microns, but not in those > 60 microns. Medial thickening was not observed over the whole range of lumen diameter. These results suggest that the mechanisms responsible for the remodelling of coronary microvessels differ between non-hypertrophied hearts with coronary hypertension and hypertrophied hearts without coronary hypertension.

Influence of age on IgE responsiveness to Dermatophagoides farinae: an immunoblot study

IgE responsiveness to Dermatophagoides farinae body extract was compared by immunoblotting among four groups of mite-sensitive asthmatic children: group I aged 0-3, group II aged 4-7, group III aged 8-11 and group IV aged 12-15. In the group I subjects, the 15-kD component was bound by 88% of sera and strongly by 56% of sera. The 25-kD component was bound by 40% of sera, but most of the binding reactions were faint. IgE binding to other components was generally low. In the group II subjects, 15- and 25-kD components were bound by 96% and 56% of sera, 30-kD and 110-kD components by 76% and 60% of sera, respectively. In addition, 18-, 40-, 59- and 80-kD components were bound by more than 30% of sera. In group III and IV subjects, the frequencies of IgE binding to these components were not significantly changed as compared with those of group II subjects. The rabbit antisera against Der f I and Der f II specifically reacted with 25- and 15-kD components, respectively. These results suggest that the 15-kD Der f II allergen is the most important antigenic constituent associated with the early IgE response to house dust-mites in mite-reactive asthmatic children.

Preferential expression of HSC70 heat shock mRNA in gerbil heart after transient brain ischemia

Inductions of mRNAs for heat shock protein (HSP) 70 and heat shock cognate protein (HSC) 70 were examined in the cerebral cortex, cerebellum, heart, lung, kidney, and liver of gerbils after a 10-min transient forebrain ischemia. HSP70 mRNA was normally expressed in a small amount in the cerebellum, lung, and kidney, but was not expressed in the heart or liver in a detectable amount. A very small amount of HSP70 mRNA was also present in the cerebral cortex. HSC70 mRNA was normally present in all the organs examined with a variety in the amount. Eight hours after the cerebral ischemia, the level of HSP70 mRNA increased in the cerebral cortex, lung, and kidney. HSC70 mRNA levels also increased in all the organs. However, the increase of HSC70 mRNA was remarkable in the heart. Transient cerebral ischemia caused subsequent hyperthermia. Treatment of gerbils with an artificial hyperthermia without cerebral ischemia increased the HSP70 and HSC70 mRNA levels as well. However, the HSC70 mRNA level in the heart after cerebral ischemia was much higher than that in the case with hyperthermic treatment. These results suggest that HSC70 mRNA was preferentially induced in the heart after transient forebrain ischemia that was not only due to the subsequent hyperthermia.

Effects of age on c-fos and c-myc gene expression in response to hemodynamic stress in isolated, perfused rat hearts

Using an ex vivo model we examined whether the age-associated modulation of proto-oncogene expression was due to the aging of the heart per se. In the two age groups of Wistar rats (2 and 18 months), expression of c-fos and c-myc genes was determined in isolated, isovolumically contracting hearts (balloon in the left ventricle) perfused with Tyrode's solution containing bovine serum and red blood cells. In both age groups, a c-fos signal was detected at 30 min, increased further at 60 min, and declined at 120 min, while the c-myc signal was detected at 60 min and increased for a further 120 min after initiation of perfusion at 25 mmHg of end-diastolic pressure (EDP). The expression of these genes by 60 min of relatively mild hemodynamic stress was depressed in old hearts compared to that in young hearts (c-fos at 0 (P < 0.05), 5 (P < 0.05) and 15 mmHg of EDP (P < 0.01); c-myc at 5 (P < 0.05) and 15 mmHg (P < 0.05)). The age-associated differences in the expression of these genes were smaller under severe hemodynamic stress (25 mmHg of EDP). Peak systolic and diastolic wall stress calculated from left ventricular pressure, cavity volume and muscle weight were similar in the two age groups. Thus, aging diminishes the expression of proto-oncogenes and seems to elevate the threshold at which hemodynamic stress to the heart results in a response at the gene level. The age-associated modulation is caused by aging of the heart per se.

Separate regulation of heme oxygenase and heat shock protein 70 mRNA expression in the rat heart by hemodynamic stress

To elucidate the role of heat shock proteins in hearts, we examined the expression of heme oxygenase (HO) and heat shock protein 70 (HSP70) mRNAs in hearts of rats subjected to hypoxia or pulmonary artery banding, both of which produce pressure overload to the right ventricle. At 3 d of hypoxia, HO mRNA levels were elevated about fourfold compared to the basal levels in both right and left ventricles, while HSP70 mRNA was not induced at all. Pulmonary artery banding markedly and immediately (within 6 h) increased HO mRNA levels in both ventricles, but induced HSP70 mRNA only in the right ventricle. This is the first in vivo evidence showing the separate regulation of HO and HSP70 gene expression in hearts by hemodynamic stress.

Coronary dilator reserve and morphological changes after relief of pressure-overload in rats

Using a rat model of short- (4 weeks) and long-term (10 weeks) ascending aortic banding and debanding, we examined the relationship between coronary dilator reserve and morphological vascular changes. After 4 or 10-week banding, in vivo systolic left ventricular pressure and ventricular wt/body wt ratio increased to a similar level, compared with controls. The coronary dilator reserve measured in an isolated heart preparation decreased similarly in the two banded groups, compared with controls. The ratios of medial to luminal area and perivascular collagen to luminal area in coronary microvessels increased in the banded groups. At 4 weeks after debanding, cardiac hypertrophy regressed to the control level, and the duration of banding did not alter the extent of the regression. The coronary dilator reserve normalized in the group debanded after 4-week banding, but did not regress in the group debanded after 10-week banding. In both of the debanded groups, the hypertrophied media regressed completely. The increased perivascular collagen regressed almost completely in the group debanded after 4-week banding, but remained greater in the group debanded after 10-week banding than in the controls. From these results, we conclude that (i) the regression of medial hypertrophy does not always improve the decreased coronary dilator reserve, and (ii) the vascular fibrosis may be the major cause of the irreversibility of decreased coronary dilator reserve in long-term cardiac hypertrophy.

Effects of duration of pressure overload on the reversibility of impaired coronary autoregulation in rats

The aim of this study was to determine the effects of duration of pressure overload on the reversibility of impaired coronary autoregulation in hypertropied hearts. The experiments were performed on 38 anesthetized male Wistar rats aged 6 to 8 weeks. The ascending aorta was banded for 4 or 10 weeks, then in some rats the bands were removed for 4 weeks. We estimated coronary hemodynamics in a model consisting of isolated non-working hearts perfused with Tyrode's solution containing bovine red blood cells and serum albumin. Myocardial mass increased significantly in 4 and 10-week banded groups compared to controls. Four weeks after debanding in 4- and 10-week banded groups, the value returned to that of controls. Autoregulation gain was significantly lower in banded groups than in controls in the range between 50 and 100 mmHg of coronary perfusion pressure. Although the gain normalized in the debanded group after 4 weeks of banding, the value in the debanded groups after 10 weeks of banding remained less than zero between 25 and 150 mmHg of perfusion pressure. In transient flow response to a stepwise increase of perfusion pressure within the autoregulatory range, promptly increased flow was followed by more rapid and greater decrease in controls than in banded groups. The flow response regressed in the debanded group after 4 weeks of banding, while it remained unchanged in the debanded group after 10 weeks of banding. Thus, duration of pressure overload alters the regression of impaired coronary autoregulation in cardiac hypertrophy.

Collagen deposition and the reversal of coronary reserve in cardiac hypertrophy

The aim of this study was to clarify how collagen deposition or medial hypertrophy of the vascular wall affects the coronary dilator reserve in pressure-overloaded hearts and whether inhibition of collagen deposition reverses the abnormalities after relief of pressure overload. We used ascending aortic banding and debanding methods and superimposed beta-aminopropionitrile in some of the banded rats (50 mg/kg i.p., twice a day). Ten weeks of banding increased in vivo peak systolic left ventricular pressure and produced medial hypertrophy, an increase in collagen deposition in the myocardial and perivascular tissues, and myocardial hypertrophy in the banded group without beta-aminopropionitrile treatment. Superimposition of beta-aminopropionitrile treatment on banding inhibited the increase in collagen deposition. In the groups debanded after the 10-week banding period, both with and without beta-amino-propionitrile treatment, medial and myocardial hypertrophy regressed 4 weeks after debanding. We estimated coronary dilator reserve in Langendorff preparations perfused with modified Tyrode's solution containing oxygenated bovine red blood cells and serum albumin. The ratio of reactive peak flow after brief ischemia-to-resting flow decreased in both of the banded groups. After debanding, the ratio remained lower in the banded group without beta-aminopropionitrile treatment than in the control group. However, debanding in the group with beta-aminopropionitrile treatment increased the ratio to a level similar to that of the control group. Thus, in pressure-overloaded cardiac hypertrophy with coronary hypertension, coronary reserve seems to be determined by medial hypertrophy independently of collagen deposition, but collagen deposition plays an important role in the reversal of vasodilator reserve after relief of the overload.

Aging effects on myocardial hypertrophic response and coronary circulation in pressure-overload

We examined the effect of age on capacity for myocardial hypertrophy, pressure-generating ability and coronary circulation after imposition of pressure-overload. Marked right ventricular and cellular hypertrophy was observed 1 week after pulmonary artery constriction in the developmental phase of rats (2 months of age) and after 3 weeks in the young-adult rats (7 months). In old rats (18 months) similar increases in peak right ventricular pressure did not produce significant hypertrophy even after 3 weeks. The right ventricular hypertrophy at the organ and cell levels in response to pressure-overload decreased with age. In vivo pressure-generating ability, which was determined by maximum isovolumic pressure during pulmonary artery occlusion, correlated with the degree of myocardial hypertrophy in each age group. During the ascending aortic constriction experiment the age-associated diminution in hypertrophic response was also observed in the left ventricle. Coronary dilator capacity, which was determined after brief ischemia in an isolated, blood-perfused, beating but nonworking heart model, was decreased in the presence of myocardial hypertrophy in young-adult rats (7 months) and in the absence of significant myocardial hypertrophy in old rats (18 months). The age-associated diminution in capacity for myocardial hypertrophy, pressure-generating ability and maladaptation in the coronary circulation may explain the higher incidence of heart failure or increased vulnerability of the myocardium to ischemic episodes during hemodynamic stress in aged patients.

Age-related differences in the expression of proto-oncogene and contractile protein genes in response to pressure overload in the rat myocardium

Cardiac adaptation to hemodynamic stress involves both quantitative (hypertrophy) and qualitative (pattern of gene expression) changes. Our previous studies have shown that advancing age in the rat is associated with diminished capacity to develop left ventricular hypertrophy in response to either ascending aortic constriction (AoC). In this study, we examined whether the expression of protooncogenes and contractile protein genes in response to AoC differs between adult (9-mo-old) and old (18-mo-old) rats. RNA was isolated from the left ventricles of AoC animals of both age groups subjected to a similar hemodynamic stress. Immediately after AoC, the levels of the ventricular expression of c-fos and c-jun protooncogenes were markedly lower in the old rats than in the adult animals. 5 d after the operation, the ratio of beta- to alpha-myosin heavy chain mRNAs increased significantly after AoC in both age groups. In contrast, AoC was associated with a marked reduction in the levels of mRNAs encoding sarcoplasmic reticulum Ca(2+)-ATPase (by 69%) and cardiac calsequestrin (by 49%) in the old rats but not in the adults. The mRNAs encoding atrial natriuretic factor and skeletal alpha-actin increased in response to AoC only in the adult rats. There were no significant differences in expression of the cardiac alpha-actin mRNA among the experimental groups. These data suggest that (a) the expression of protooncogenes in response to acute pressure overload is significantly reduced in the aged rats and (b) the pattern of expression of the contractile protein gene in response to AoC in the old rats differs qualitatively as well as quantitatively from that in younger animals. These age-related differences may play a role in the higher frequency of heart failure in the aged during hemodynamic stress.

Interaction of lectins with human IgE: IgE-binding property and histamine-releasing activity of twelve plant lectins

We examined the IgE-binding reaction and the histamine-releasing response of basophils to a panel of 12 lectins: concanavalin A (Con A), Lens culinaris hemagglutinin (LcH), Pisum sativum agglutinin (PSA), wheat germ agglutinin (WGA), soybean agglutinin (SBA), Bauhinia purpurea agglutinin (BPA), peanut agglutinin (PNA), Ricinus communis agglutinin I (RCA-I), Lotus tetragonolobus agglutinin (Lotus A), Ulex europeus agglutinin I (UEA-I), phytohemagglutinin E (PHA-E) and phytohemagglutinin L (PHA-L), IgE from allergic patients bound with high affinity to Con A, LcH, PSA, RCA-I and PHA-E, and with lower affinity to WGA, BPA, Lotus A and UEA-I, but they did not bind to SBA, PNA or PHA-L. There was no apparent individual difference in the reactivity of IgE to these lectins between 10 IgE preparations from allergic patients. The binding to these lectins, except Lotus A and UEA-I, were competitively inhibited by the lectin-specific sugars or glycopeptide. Upon stimulation by Con A, LcH, PSA, WGA, RCA-1 and PHA-E, leukocytes from allergic patients showed a significant release of histamine, but cells from IgE-deficient subjects did not respond to these lectins. The histamine-releasing responses by these lectins were also inhibited by specific sugars or glycopeptides.

Effects of age on right ventricular hypertrophic response to pressure-overload in rats

To examine the effects of age on hypertrophic response to pressure-overload in the right ventricle, we determined the rate and extent of hypertrophy in three age groups of Wistar rats: 2, 7 and 18 months. We created pulmonary artery constriction so that increases in right ventricular pressure were similar in those groups. One or 3 weeks after pulmonary artery constriction, the rats were sacrificed and hypertrophic response was estimated from right ventricular weight, myocyte width and protein content. In the 2-month-old rats, significant hypertrophy was observed 1 and 3 weeks after pulmonary artery constriction in terms of right ventricular weight/body weight (161% of controls at 1 week and 209% at 3 weeks), right ventricular weight/tibial length (161 and 251%, respectively) and right ventricular weight/left ventricular weight (174 and 211%, respectively). In the 7-month-old rats, significant hypertrophy was observed only at 3 weeks, but was not observed even at 3 weeks in the 18-month-old rats. The age-associated decrease and delay in hypertrophic response was also observed at cellular (myocyte width) and biochemical (protein content) levels. Thus, there is an age-associated diminution in the rate and extent of myocardial hypertrophy in the right ventricle.

Effect of age on coronary circulation after imposition of pressure-overload in rats

We examined the effects of pressure overload on coronary circulation in young adult (7 months old) and old rats (18 months old). Four weeks after the ascending aorta was banded, in vivo left ventricular pressure was measured to estimate the degree of pressure load. In the two age groups, similar increases in peak left ventricular pressure were observed (113 +/- 7 mm Hg in sham-operated rats versus 160 +/- 11 mm Hg in banded rats of the young adult group; 103 +/- 7 mm Hg in sham-operated rats versus 156 +/- 11 mm Hg in banded rats of the old group). After isolating the hearts, they were perfused with Tyrode's solution containing bovine red blood cells and albumin. Resting coronary perfusion pressure-flow relations and reactive hyperemic response after a 40-second ischemia were obtained under beating but nonworking conditions. In young adult banded rats, significant myocardial hypertrophy was observed at the organ level (124% of controls in left ventricular dry weight/body weight ratio; 119% in left ventricular dry weight/tibial length ratio) and at the cell level. Minimal coronary vascular resistance obtained by the perfusion pressure-peak flow relation during reactive hyperemia increased to 150% of controls, and coronary flow reserve decreased significantly. In contrast, myocardial hypertrophy was not observed at the organ or cell level in old banded rats. However, minimal coronary vascular resistance increased, and flow reserve decreased significantly. Thus, pressure overload with coronary arterial hypertension caused abnormalities of the coronary circulation in old subjects even in the absence of myocardial hypertrophy.

Relationship between asthma and seasonal allergic rhinitis in schoolchildren

The relationship between sensitization to common allergens and the development of asthma and seasonal allergic rhinitis (SAR) was investigated in a total of 419 schoolchildren in a farming community where allergens of both Dermatophagoides farinae (Df) and orchard grass (OG) pollen predominate. Twelve subjects (2.9%) were found to have asthma and 35 subjects (8.4%) SAR. There was no significant association between occurrences of asthma and SAR. The incidence of asthma correlated with DF-specific IgE levels but not with OG-specific IgE levels, whereas that of SAR correlated with OG-specific IgE levels but not with Df-specific IgE levels. No significant correlation was detected between IgE antibody levels against Df and OG. These results suggest that asthma occurs independently of SAR.