Effectiveness of mRNA COVID-19 vaccines against symptomatic SARS-CoV-2 infections during the SARS-CoV-2 Omicron BA.1 and BA.2 epidemic in Japan: vaccine effectiveness real-time surveillance for SARS-CoV-2 (VERSUS)

BACKGROUND

Evaluating COVID-19 vaccine effectiveness (VE) domestically is crucial for assessing and determining national vaccination policy. This study aimed to evaluate VE of mRNA COVID-19 vaccines in Japan.

METHODS

We conducted a multicenter test-negative case-control study. The study comprised individuals aged ≥16 visiting medical facilities with COVID-19-related signs or symptoms from 1 January to 26 June 2022, when Omicron BA.1 and BA.2 were dominant nationwide. We evaluated VE of primary and booster vaccination against symptomatic SARS-CoV-2 infections and relative VE of booster compared with primary.

RESULTS

We enrolled 7,931 episodes, including 3,055 test positive. The median age was 39, 48.0% were male, and 20.5% had underlying medical conditions. In individuals aged 16 to 64, VE of primary vaccination within 90 days was 35.6% (95% CI, 19.0-48.8%). After booster, VE increased to 68.7% (60.6-75.1%). In individuals aged ≥65, VE of primary and booster was 31.2% (-44.0-67.1%) and 76.5% (46.7-89.7%), respectively. Relative VE of booster compared with primary vaccination was 52.9% (41.0-62.5%) in individuals aged 16 to 64 and 65.9% (35.7-81.9%) in individuals aged ≥65.

CONCLUSIONS

During BA.1 and BA.2 epidemic in Japan, mRNA COVID-19 primary vaccination provided modest protection. Booster vaccination was necessary to protect against symptomatic infections.

Status epilepticus during correction of hyponatremia in a patient with Alzheimer's disease: A case report

An 83-year-old Japanese man with Alzheimer’s disease was admitted to our hospital for treatment of hyponatremia resulting from water intoxication. During hospitalization, the patient developed focal impaired awareness seizures, focal to bilateral tonic-clonic seizures, and subsequent status epilepticus. Electroencephalogram during focal impaired awareness seizures showed rhythmic 5–9 Hz theta activity in the right frontotemporal region. Electroencephalogram during focal to bilateral tonic-clonic seizures showed bilateral polyspikes. Electroencephalogram during an interseizure period revealed sharp waves in the right frontal region. Continuous intravenous administration of midazolam was the only effective treatment for status epilepticus. The patient died of aspiration pneumonia on day 58. Hyponatremia-associated status epilepticus is rare; in the present case, multifocal epileptogenicity resulting from Alzheimer’s disease and hyponatremia-associated elevation of glutamate levels in the synaptic cleft may have contributed to the onset of focal to bilateral tonic-clonic seizures with subsequent status epilepticus.

Native valve endocarditis due to Escherichia coli infection: a case report and review of the literature

Background

Infective endocarditis due to Escherichia coli is a rare disease but is increasing in frequency, especially among older women. In addition, its mortality rate is higher than that of endocarditis due to the HACEK-group gram-negative bacteria (Haemophilus spp., Aggregatibacter spp., Cardiobacterium hominis, Eikenella corrodens, and Kingela spp.).

Case presentation

A 58-year-old Japanese woman with a history of alcohol abuse was admitted to our hospital because of a fever. She was diagnosed with infective endocarditis due to E. coli based on repeated blood cultures and transthoracic echocardiography, which revealed vegetations attached to the anterior leaflet and chordae tendineae of the mitral valve. Despite administration of sulbactam/ampicillin and gentamycin, she developed purulent spondylitis during hospitalization and required treatment with meropenem administration for 6 weeks, leading to resolution of the endocarditis. She took oral levofloxacin for 2 months, and the spondylitis was completely cured 7 months after discharge.

Conclusion

Escherichia coli affects native valves without degenerative valvulopathy rather than prosthetic valves, especially in patients with risk factors such as an immunosuppressive status, excessive alcohol consumption, or treatment with hemodialysis. Peripheral embolization, congestive heart failure, and valve-ring abscesses are major complications of E. coli endocarditis; notably, infective myocarditis can also occur. The mortality and surgical intervention rates are 21% and 42%, respectively. Physicians should be cognizant of the necessity of surgical intervention when E. coli endocarditis is resistant to antibiotic therapy.

Multiple spontaneous hemorrhages after commencing warfarin therapy

A 94 year-old Japanese woman with renal dysfunction was admitted to our hospital for congestive heart failure caused by atrial fibrillation with rapid ventricular response. Considering the risk of stroke, warfarin was commenced. However, she developed shock following brachial and retroperitoneal hemorrhage 4 days after starting warfarin despite not being over-anticoagulated. She recovered after receiving blood transfusion and intravenous vitamin K2. Bleeding during warfarin administration occurs more frequently in older individuals with lower glomerular filtration rates, especially within the first 30 days of warfarin treatment. Physicians should therefore check for unexpected bleeding after commencing warfarin and be prepared to reverse anticoagulation.

Acute suppurative thyroiditis caused by Streptococcus agalactiae infection: a case report

Acute suppurative thyroiditis is a serious disease; therefore, its diagnosis in the acute phase is important. Fine needle aspiration biopsy of the thyroid gland plays a pivotal role in the diagnosis of acute suppurative thyroiditis. Appropriate culture technique and optimal imaging modalities are also important for its diagnosis.

Pneumatosis intestinalis with a benign clinical course: a report of two cases

Background

Pneumatosis intestinalis (PI) is a rare condition characterized by the presence of gas within the gastrointestinal tract wall. Most cases of PI have a benign clinical course, although some have serious outcomes. Mechanical stress on or bacterial infection of the gastrointestinal tract wall may be responsible for the onset of PI, but the detailed mechanism of PI pathogenesis is still unclear. Here, we describe two Japanese patients presenting with benign PI.

Case presentation

Case 1, a 37-year-old previously healthy male patient, had a 1-week history of abdominal pain, and case 2, a 78-year-old female diabetic patient, had a 2-week history of voglibose treatment and abdominal pain. Intramural gas was mainly distributed in the colon in case 1 and in the small intestine in case 2. Interestingly, neither patient showed obvious inflammatory signs upon admission and recovered spontaneously with conservative treatment, including fasting and fluid infusion without antibiotics. Voglibose treatment was terminated in case 2. Recent studies have shown the presence of nonpathogenic bacteria, such as Clostridium spp., in PI lesions, which usually play an important role in modulating the tolerance of the gastrointestinal immune responses. The benign clinical course and spontaneous resolution of PI in these patients, without specific treatment, suggests that nonpathogenic indigenous bacteria in the gastrointestinal tract participate in the pathogenesis of PI.

Conclusion

In patients with benign PI, the absence of an inflammatory response and the spontaneous resolution of the disease without specific treatment suggest the participation of nonpathogenic indigenous bacteria of the gastrointestinal tract.

Multiple liver abscesses and bacteremia caused by Streptococcus constellatus infection: a case report

The Streptococcus milleri group (SMG) comprises commensal mucosal bacteria. Pyogenic liver abscesses due to hematogenous SMG infection are rare but can be observed even in healthy patients. In such cases, physicians should consider the existence of primary lesions that allow penetration of the SMG.

Bacterial Pneumonia Caused by Streptococcus pyogenes Infection: A Case Report and Review of the Literature

A 78-year-old Japanese man was admitted to our hospital because of fever lasting for 4 days. His white blood cell count and C-reactive protein level were elevated and computed tomography of the chest showed bronchopneumonia in the right upper lobe of the lung. Streptococcus pyogenes was detected from sputum and blood culture samples on admission and administration of ampicillin/sulbactam was effective. Although our patient’s clinical course was good, S. pyogenes pneumonia commonly shows a high rate of fatality and septicemia, and may affect a previously healthy population. Physicians should be aware of pernicious characteristics of S. pyogenes pneumonia.

Nutritional parameters affecting severity of pneumonia and length of hospital stay in patients with pneumococcal pneumonia: a retrospective cross-sectional study

Background

Pneumococcal pneumonia is the most common form of community-acquired pneumonia (CAP). Although a pneumococcal conjugate vaccine has contributed to a reduction in the incidence of pneumococcal pneumonia among older children and adults, no significant decrease in the incidence has been observed among persons aged ≥65 years. A low body mass index and hypoalbuminemia are common in Japanese patients with CAP, but the association of other nutritional parameters with the severity of pneumonia or length of hospital stay in patients with pneumococcal pneumonia is unclear.

Methods

Fifty-seven previously healthy inpatients who presented with pneumococcal pneumonia were divided into two groups: those aged ≥65 years (n = 36) and those aged <65 years (n = 21). Patients’ characteristics (the Confusion, Urea, Respiratory rate, Blood pressure, age >65 years (CURB-65) score), the pneumonia severity index (PSI), and inflammatory and metabolic nutritional parameters were compared between the two groups.

Results

The older group showed significantly lower serum albumin and cholinesterase (ChE) levels. Multivariate linear regression analysis revealed that the PSI was positively correlated with age in both groups. In the younger age group, both the CURB-65 score and PSI showed significant negative correlations with the serum ChE level, and there was a significant negative correlation between the length of stay and serum total cholesterol (T-cho) level. In the older group, the fasting period, lymphocyte count, and age showed significant positive correlations with the length of stay. There was a significant negative correlation between the length of stay and serum albumin level, but no correlation with the serum ChE or T-cho levels, in the older patients.

Conclusions

Our findings suggest that in patients aged <65 years, age and serum ChE and T-cho levels were associated with both the severity of pneumococcal pneumonia and length of stay. In contrast, the length of stay in older patients was associated with multiple factors that differed from those in younger patients. These differences may reflect age-related immunosenescence in older patients and a greater effect of serum ChE and T-cho levels on immunity in younger patients.

Cross-Sectional Study of Patients With Onset of Acute Coronary Syndrome During Statin Therapy

Background

Although statin therapy significantly reduces cardiovascular morbidity and mortality, atherosclerotic plaque progresses in some patients taking statins. This study investigated the factors associated with onset of acute coronary syndrome (ACS) early after the initiation of statin therapy.

Methods

Consecutive patients taking statins who presented with ACS (n = 64) were divided into < 1-year and > 1-year groups based on the duration of statin therapy. Patient characteristics, coronary risk factors, lesion locations, and percutaneous intervention procedures were compared between groups.

Results

The < 1-year group was significantly younger (57.6 ± 11.9 years vs. 76.6 ± 9.1 years, P < 0.01), had significantly higher body mass index (27.22 ± 4.20 kg/m² vs. 24.60 ± 4.65 kg/m², P < 0.05), higher proportion of males (94% vs. 70%, P < 0.05), higher proportion of current smokers (61% vs. 17%, P < 0.01), and lower proportions taking aspirin and calcium antagonists (both 17% vs. 57%, P < 0.05) than the > 1-year group. In the < 1-year group, there were significant correlations between the low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) levels (r = 0.649, P = 0.004) and between the TG and hemoglobin (Hb)A1c levels (r = 0.552, P = 0.018), but these correlations were not observed a year before admission. TG level was the only parameter associated with LDL-C and HbA1c levels.

Conclusions

A linear correlation between the LDL-C and TG levels, obesity, older age, male sex, and smoking may be associated with increased risk of onset of ACS early after the initiation of statin therapy. Prospective cohort studies are needed to further explore these interactions.

Secondary brain abscess following simple renal cyst infection: a case report

BACKGROUND

Escherichia coli (E. coli) is the most common causative bacteria of neonatal meningitis, but hematogenous intracranial E. coli infection is rare in adults. Moreover, intracranial abscess formation owing to E. coli, including brain abscesses and subdural empyema formation, is extremely rare. We herein present a case involving a patient with a brain abscess owing to E. coli following a simple renal cyst infection. A review of the literature is also presented.

CASE PRESENTATION

A 77-year-old Japanese woman with a history of polymyalgia rheumatica was admitted to our hospital because of persistent fever, right flank pain, and pyuria. Intravenous antibiotics were administered; however, her level of consciousness deteriorated 6 days after admission. Contrast-enhanced magnetic resonance imaging showed a brain abscess in the left occipital lobe and pyogenic ventriculitis. Enhanced abdominal computed tomography revealed a right renal cyst with heterogeneous content. Culture of urine, blood, and aspirated pus from the infected cyst revealed E. coli with identical antibiotic sensitivity in all sites, suggesting that the cyst infection and subsequent bacteremia might have caused the brain abscess. The patient recovered after a 6-week course of meropenem.

CONCLUSION

The prognosis of patients with E. coli-associated intracranial abscess is usually poor. Advanced age and immunosuppression may be potent risk factors for intracranial abscess formation owing to the hematogenous spread of E. coli.

Two patients with ruptured posterior inferior pancreaticoduodenal artery aneurysms associated with compression of the celiac axis by the median arcuate ligament

Patients with compression of the celiac axis by the median arcuate ligament may develop aneurysms in the pancreaticoduodenal arcades. We experienced two cases of ruptured pancreaticoduodenal artery aneurysm associated with this condition. Both patients presented with abdominal pain and shock, and abdominal contrast-enhanced computed tomography showed retroperitoneal hematoma and compression of the celiac axis by the median arcuate ligament. Both patients were successfully treated by coil embolization. Patients with celiac axis compression or stenosis may develop recurrent aneurysms unless revascularization of the celiac axis is performed. Long-term follow-up is required because aneurysms may develop after 10 years or longer.

Myocarditis, hepatitis, and pancreatitis in a patient with coxsackievirus A4 infection: a case report

Viral myocarditis presents with various symptoms, including fatal arrhythmia and cardiogenic shock, and may develop chronic myocarditis and dilated cardiomyopathy in some patients. We report here a case of viral myocarditis with liver dysfunction and pancreatitis. A 63-year-old man was admitted to our hospital with dyspnea. The initial investigation showed pulmonary congestion, complete atrioventricular block, left ventricular dysfunction, elevated serum troponin I, and elevated liver enzyme levels. He developed pancreatitis five days after admission. Further investigation revealed a high antibody titer against coxsackievirus A4. The patient’s left ventricular dysfunction, pancreatitis, and liver dysfunction had resolved by day 14, but his troponin I levels remained high, and an endomyocardial biopsy showed T-lymphocyte infiltration of the myocardium, confirming acute myocarditis. The patient underwent radical low anterior resection five weeks after admission for advanced rectal cancer found incidentally. His serum troponin I and plasma brain natriuretic peptide levels normalized six months after admission. He has now been followed-up for two years, and his left ventricular ejection fraction is stable.

This is the first report of an adult with myocarditis and pancreatitis attributed to coxsackievirus A4. Combined myocarditis and pancreatitis arising from coxsackievirus infection is rare. This patient’s clinical course suggests that changes in his immune response associated with his rectal cancer contributed to the amelioration of his viral myocarditis.

Transient Plasmacytosis With Trisomy of Chromosome 8 in a Patient With Multiple Myeloma: A Case Report

A 96-year-old woman with a 5-year history of multiple myeloma was admitted to our hospital because of increasing fatigue and fever. Bone marrow plasma cell analysis showed t(11;14), del(13q), and del(17p13). Her condition deteriorated, and she developed plasmacytosis resembling plasma cell leukemia. Chromosome analysis showed trisomy of chromosome 8 in the circulating plasma cells. The plasmacytosis resolved spontaneously without chemotherapy after about 5 weeks, and the trisomy became undetectable. The findings suggest that trisomy 8 might have contributed to the transient plasmacytosis, and that chromosome 8 carries genes associated with plasma cell proliferation, maturation, and apoptosis.

Enteral Nutrition Related Complications Relevant to Alteration of Formulas in Two Critically Ill Pediatric Patients

The early institution of enteral nutrition is associated with beneficial outcomes and intestinal growth in pediatric patients. However, the number, frequency, and types of unfavorable events occurring with particular formulas are undefined. We experienced unexpected complications in two cases following a change in formula. One case diagnosed with myotubular myopathy experienced highly-increased gastric residuals and watery diarrhea leading to decreased calorie intake and weight loss. The second case with campomelic dysplasia suffered liver dysfunction and fever. In both cases, symptoms developed soon after of the change in formula and improved after resumption of the previous formula. Both cases had undergone tracheostomy and artificial ventilation, and had a history of feeding the same formula for an extended period of time. In chronic care patients such as ours, a change in formula may cause unexpected adverse events; therefore, caution is warranted.

Application of alkali metal-doped carbons for hydrogen recovery and isotope separation

Hydrogen-sorption isotherms of alkali metal-doped carbons at 77 K were determined for promoting application of these materials as hydrogen-recovery and isotope-separation agent. The hydrogen-sorption behavior of rubidium-doped Grafoil, with composition of RbC24, showed high sorption ability against hydrogen at low pressure. Taking into account the fact that sorption-desorption was fast and reversible, and the equilibrium pressure at half coverage was very low, i.e., 40 Pa, RbC24 prepared from Grafoil is promising as a recovery agent for hydrogen gas at low pressure. The hydrogen (H2)/deuterium(D2)-sorption isotherms of potassium-doped carbons with composition of KC10, prepared from multi wall carbon nanotube (MWCNT) and carbons derived from petroleum cokes with heat-treatment temperatures of 1000 and 1500 degrees C, were also determined. Isotope separation coefficient was estimated from those isotherms. A very large isotope effect was found for KC10 prepared from MWCNT, comparable to those prepared from carbons with heat-treatment temperatures of 1000 or 1500 degrees C. However, a severe problem was found for KC10 (MWCNT) that repetition of the sorption-desorption cycles resulted in the decrease of the sorbed amount of H2 and D2.

Reciprocal expression of vascular endothelial growth factor and nitric oxide synthase by coronary arterial wall cells during chronic inhibition of nitric oxide synthesis in rats

Chronic inhibition of nitric oxide (NO) synthesis by oral administration of N(G)-nitro-L-arginine methyl ester (L-NAME) causes hypertension and produces arteriosclerosis in rats. Balloon injury induces upregulation of vascular endothelial growth factor (VEGF) in medial smooth muscle cells of the rat arterial wall, and NO secreted by a restored endothelium acts as the negative feedback mechanism that downregulates VEGF expression to basal levels. In this study, we tested the hypothesis that a reciprocal relation between VEGF and NO would be established in a rat model of chronic NO blockade. Male Wister rats received plain drinking water (n = 10) or L-NAME (0.5 mg/ml) in the drinking water (n = 11) for 6 weeks. After 6 weeks, the wall-to-lumen ratios and perivascular fibrosis in the coronary arteries were greater in the L-NAME group than in the control group. NO synthase-positive cells in the intima were abundantly observed in the control group, whereas no such cells were seen in the L-NAME group. In contrast, the number of VEGF-positive smooth muscle cells in the media was greater in the L-NAME group than in the control group. These findings strongly suggest a reciprocal relation between VEGF and NO even in a rat model of chronic NO blockade.

PPARgamma ligand inhibits osteopontin gene expression through interference with binding of nuclear factors to A/T-rich sequence in THP-1 cells

Peroxisome proliferator-activated receptor gamma (PPARgamma) is a member of the nuclear receptor superfamily that acts as a key player in adipocyte differentiation, glucose metabolism, and macrophage differentiation. Osteopontin (OPN), a component of extracellular matrix, is elevated during neointimal formation in the vessel wall and is synthesized by macrophages in atherosclerotic plaques. In the present study, we investigated the molecular mechanisms regulating OPN gene expression by PPARgamma in THP-1 cells, a cell line derived from human monocytic leukemia cells. Northern and Western blot analyses showed that exposure of THP-1 cells to PMA (phorbol 12-myristate 13-acetate) increases OPN mRNA and protein levels in a time-dependent manner. PMA-induced OPN expression was significantly decreased by troglitazone (Tro) and other PPARgamma ligands. Transient transfection assays of the human OPN promoter/luciferase construct showed that PPARgamma represses OPN promoter activity, and the PPARgamma-responsive region within the OPN promoter lies between -1000 and -970 relative to the transcription start site. Site-specific mutation analysis and electrophoretic mobility shift assays indicated that a homeobox-like A/T-rich sequence between -990 and -981, which functions as a binding site for PMA-induced nuclear factors other than PPARgamma, mediates the repression of OPN expression by Tro. Furthermore, concatenated A/T-rich sequences conferred the PPARgamma responsiveness on the heterologous promoter. Taken together, these data suggest that PPARgamma ligand inhibits OPN gene expression through the interference with the binding of nuclear factors to A/T-rich sequence in THP-1 cells.

PPARγ Ligand Inhibits Osteopontin Gene Expression Through Interference With Binding of Nuclear Factors to A/T-Rich Sequence in THP-1 Cells

Peroxisome proliferator-activated receptor γ (PPARγ) is a member of the nuclear receptor superfamily that acts as a key player in adipocyte differentiation, glucose metabolism, and macrophage differentiation. Osteopontin (OPN), a component of extracellular matrix, is elevated during neointimal formation in the vessel wall and is synthesized by macrophages in atherosclerotic plaques. In the present study, we investigated the molecular mechanisms regulating OPN gene expression by PPARγ in THP-1 cells, a cell line derived from human monocytic leukemia cells. Northern and Western blot analyses showed that exposure of THP-1 cells to PMA (phorbol 12-myristate 13-acetate) increases OPN mRNA and protein levels in a time-dependent manner. PMA-induced OPN expression was significantly decreased by troglitazone (Tro) and other PPARγ ligands. Transient transfection assays of the human OPN promoter/luciferase construct showed that PPARγ represses OPN promoter activity, and the PPARγ-responsive region within the OPN promoter lies between −1000 and −970 relative to the transcription start site. Site-specific mutation analysis and electrophoretic mobility shift assays indicated that a homeobox-like A/T-rich sequence between −990 and −981, which functions as a binding site for PMA-induced nuclear factors other than PPARγ, mediates the repression of OPN expression by Tro. Furthermore, concatenated A/T-rich sequences conferred the PPARγ responsiveness on the heterologous promoter. Taken together, these data suggest that PPARγ ligand inhibits OPN gene expression through the interference with the binding of nuclear factors to A/T-rich sequence in THP-1 cells.

Troglitazone, a PPARgamma ligand, inhibits osteopontin gene expression in human monocytes/macrophage THP-1 cells

Peroxizome proliferator-activated receptor-gamma (PPARgamma) is a member of the nuclear receptor family of transcription factors that regulate adipocyte differentiation. Recent studies indicate that liganded PPARgamma not only promotes differentiation but also inhibits the activation of macrophages. Osteopontin, a component of extracellular matrix, is synthesized by macrophages in atherosclerotic plaques. In this study, we examined whether PPARgamma ligand regulates osteopontin gene expression in THP-1 cells, a cell line derived from human monocytic leukemia cells which can differentiate to macrophage upon stimulation with phorbol ester PMA. Northern blot analysis showed that osteopontin expression is markedly induced in response to PMA. Troglitazone, a PPARgamma ligand, dramatically attenuated the PMA-induced osteopontin expression. Transient transfection assays of the human osteopontin promoter/luciferase construct which contains a 5'-flanking region between -1500 and +87 relative to the transcription start site demonstrate that either treatment with troglitazone or cotransfection of PPARgamma expression vector inhibits osteopontin promoter activity. These data indicate that troglitazone reduces osteopontin gene expression at transcriptional level through PPARgamma activation, and suggest the role of troglitazone in inhibiting the ability of macrophages to produce extracellular matrix, which is particularly relevant to atherosclerotic plaque formation.

Hypoxia induces transcription of the plasminogen activator inhibitor-1 gene through genistein-sensitive tyrosine kinase pathways in vascular endothelial cells

A decline in oxygen concentration perturbs endothelial function, which promotes local thrombosis. In this study, we determined whether hypoxia in the range of that observed in pathophysiological hypoxic states stimulates plasminogen activator inhibitor-1 (PAI-1) production in bovine aortic endothelial cells. PAI-1 production, measured by ELISA, was increased by 4.7-fold (P<0.05 versus normoxic control, n=4) at 12 hours after hypoxic stimulation. Northern blot analysis showed the progressive time-dependent increase in the steady-state level of PAI-1 mRNA expression by hypoxia, which reached a 7.5-fold increase (P<0.05 versus control, n=4) at 12 hours. Deferoxamine, which has been known to bind heme protein and to reproduce the hypoxic response, induced PAI-1 production at both the mRNA and protein levels. The half-life of PAI-1 mRNA, as determined by a standard decay assay, was not affected by hypoxia, suggesting that induction of PAI-1 mRNA was regulated mainly at the transcriptional level. Transient transfection assays of the human PAI-1 promoter-luciferase construct indicates that a hypoxia-responsive region lies between -414 and -107 relative to the transcription start site, where no putative hypoxia response element is found. The hypoxia-mediated increase in PAI-1 mRNA levels was attenuated by the tyrosine kinase inhibitors genistein (50 micromol/L) and herbimycin A (1 micromol/L), whereas PD98059 (50 micromol/L, MEK1 inhibitor), SB203580 (10 micromol/L, p38 mitogen-activated protein kinase inhibitor), and calphostin C (1 micromol/L, protein kinase C inhibitor) had no effect on the induction of PAI-1 expression by hypoxia and deferoxamine. Genistein but not daidzein blocked the production of hypoxia- and deferoxamine-induced PAI-1 protein. Thus, we conclude that hypoxia stimulates PAI-1 gene transcription and protein production through a signaling pathway involving genistein-sensitive tyrosine kinases in vascular endothelial cells.

Zinc finger transcription factor Egr-1 activates Flt-1 gene expression in THP-1 cells on induction for macrophage differentiation

Activation of macrophages is a hallmark of atherosclerosis. Stimulation of human monocytic leukemia THP-1 cells with phorbol 12-myristate 13-acetate (PMA) is known to induce a variety of genes whose function is relevant to activated macrophages. Flt-1, a receptor tyrosine kinase for vascular endothelial growth factor, is expressed in macrophages as well as in endothelial cells and mediates the biological response to vascular endothelial growth factor. In this study, we investigated the molecular mechanisms underlying the inducible expression of the flt-1 gene during the activation of THP-1 cells. Reverse transcription-polymerase chain reaction analysis showed that exposure of THP-1 cells to PMA increases flt-1 mRNA and protein levels. A transfected reporter gene, consisting of the human flt-1 promoter region coupled to the luciferase gene, indicated a direct effect of PMA on transcriptional activity. Transfection analysis of a series of 5'-deletion constructs and site-directed mutants localized the PMA-responsive region to a DNA stretch from -174 to -166, which represents overlapping Egr-1/Sp1 transcription factor-binding sites. Competitive gel mobility shift assays and supershift assays showed that PMA induces the binding of Egr-1 to this site. Consistent with these findings, the Egr-1 expression plasmid strongly induced flt-1 promoter activity in a sequence-specific manner. Taken together, our data demonstrate that PMA induces flt-1 gene transcription through an induction of Egr-1 in THP-1 cells, thus providing new evidence that the flt-1 gene is a direct target of Egr-1, the transcription factor primarily induced on macrophage differentiation.

ET(A) receptor antagonist ameliorates nephrosclerosis and left ventricular hypertrophy induced in rat by prolonged inhibition of nitric oxide synthesis

We investigated the ability of the ETA receptor antagonist T-0115 and the angiotensin-converting enzyme (ACE) inhibitor imidapril hydrochloride to prevent hypertensive complications induced in rats by chronic inhibition of nitric oxide (NO). Male Wistar rats were given distilled water (control), NG-nitro-L-arginine methyl ester (L-NAME) 500 mg/l, or L-NAME plus imidapril 10 mg/l in the drinking water. In rats treated with L-NAME 500 mg/l plus T-0115, T-0115 was given in the food at a dose of 0.2 mg/g food or 0.6 mg/g food. We then collected 24-h urine samples at 2, 4, and 6 wk, obtained blood samples at 6 wk, and histologically examined the kidney and heart. L-NAME markedly reduced the levels of NO metabolites in serum and urine while increasing the tail-cuff blood pressure, the urinary albumin level (1.90+/-0.65 vs. 0.05+/-0.02 mg/d/100 g in control), and the area of the left ventricular wall (83.3+/-3.0 vs. 69.8+/-1.8 mm2 in control). The plasma renin activity was significantly higher in rats treated with L-NAME than in the control rats. The concomitant administration of T-0115 0.6 mg/g food with L-NAME ameliorated the tail-cuff pressure and the albuminuria (0.56+/-0.23 mg/d/100 g), although to a lesser extent than the changes seen with imidapril 10 mg/l. T-0115 0.6 mg/g food prevented left ventricular hypertrophy as effectively as imidapril 10 mg/l (70.8+/-1.8 with T-0115 vs. 68.3+/-2.7 mm2 with imidapril). Chronic inhibition of NO synthesis produced left ventricular hypertrophy and nephrosclerosis. Our results demonstrate that inhibition of the renin-angiotensin system morely effectively prevents nephrosclerosis than does the blockade of ETA receptors in a model of hypertension induced by chronic NO blockade. However, inhibition of the ET-1 pathway appeared to be as effective as ACE inhibitors in preventing left ventricular hypertrophy in this model.

Antihypertensive agents prevent nephrosclerosis and left ventricular hypertrophy induced in rats by prolonged inhibition of nitric oxide synthesis

We investigated the ability of the angiotensin converting enzyme (ACE) inhibitor imidapril hydrochloride, and of the calcium channel blocker amlodipine besilate, to prevent nephrosclerosis and left ventricular hypertrophy (LVH) in rats with hypertension induced by chronic inhibition of nitric oxide (NO). Male Wistar rats were given distilled water (control), NG-nitro-L-arginine methyl ester (L-NAME) 500 mg/L, L-NAME plus imidapril 10 mg/L or 100 mg/L, or L-NAME plus amlodipine 50 mg/L or 100 mg/L in the drinking water (n = 10-12). We then collected 24-h urine samples at 2, 4, and 6 weeks, obtained blood samples at 6 weeks, and histologically examined the kidney and heart. L-NAME markedly reduced the levels of NO metabolites in serum and urine while increasing the tail-cuff blood pressure, the urinary albumin level (1.90 +/- 0.65 v 0.05 +/- 0.02 mg/day/100 g in control), and the area of the left ventricular wall (83.3 +/- 3.0 v 69.8 +/- 1.8 mm2 in control). Nephrosclerosis and myocardial interstitial fibrosis were documented histologically. The plasma renin activity was significantly higher in rats treated with L-NAME than in the control rats. The concomitant administration of imidapril (10 mg/L) with L-NAME completely normalized the tail-cuff pressure, the LVH (70.8 +/- 1.8 mm2), the albuminuria (0.05 +/- 0.01 mg/day/100 g), and the histologic changes. Amlodipine (50 mg/L) also ameliorated the L-NAME-induced effects, but to a lesser extent. Thus, the chronic inhibition of NO synthesis in rats produced nephrosclerosis and LVH that were effectively prevented by giving imidapril at a dose lower than that of amlodipine. We conclude that ACE inhibitors can prevent nephrosclerosis and LVH even in the presence of a reduction in NO production, implying that in rats the inhibition of the renin-angiotensin system is more effective than the blockade of calcium channels in preventing hypertensive tissue injury.

Transient hypertension due to adrenal hemorrhage in a patient with von Recklinghausen's disease

A 29-year-old man with von Recklinghausen's disease suddenly developed severe epigastric pain and was admitted to hospital. Physical examination revealed elevated blood pressure (200/130 mmHg) and tachycardia (162 bpm). Initially, he was suspected to have appendicitis, and appendectomy was performed immediately; however, appendicitis was not demonstrable pathologically. Retroperitoneal hematoma was found incidentally during the operation. Further clinical and laboratory examination demonstrated a marked increase in the urinary excretion of catecholamines. There was no evidence of pheochromocytoma on computed tomography or magnetic resonance imaging; however, these imaging studies simply showed a hematoma at the right adrenal gland. Transient hypertension and tachycardia, resembling pheochromocytoma, was caused by adrenal hemorrhage.