Matrix metalloproteinase 9 (MMP-9) in patients with rheumatoid arthritis

Matrix metalloproteinase 9 (MMP-9) degrades type IV collagen, gelatin, type V collagen and type XI collagen. We measured proMMP-9 and proMMP-9-TIMP-1 complex in sera and joint fluids by sandwich ELISA, and immunohistochemically examined the expression of this enzyme in joint tissues from patients with rheumatoid arthritis (RA). ProMMP-9 was purified from the culture medium of HT 1080 cells by the three steps of chromatography. Purified proMMP-9 and activated MMP-9 by aminophenylmercuric acetate showed two bands of 92 and 67 kDa on gelatin zymography. We raised two monoclonal antibody clones, named 2G9 and 8G7, against proMMP-9. 2G9 and 8G7 reacted with proMMP-9 in western blotting and these clones reacted not only with proMMP-9, but also with proMMP-9-TIMP-1 complex in sandwich ELISA, respectively. The proMMP-9 concentration in 86 sera (749.4±940.2 ng/ml) and 54 joint fluids (4539.9±7681.5 ng/ml) from patients with RA was significantly higher than those of patients with osteoarthritis (15 sera: 139.0±149.6 ng/ml; 16 joint fluids: 655.0±1982.8 ng/ml) and control (37 sera: 266.7±120.4 ng/ml; three joint fluids: 0 ng/ml). The immunohistochemistry with 2G9 monoclonal antibody showed that proMMP-9 were expressed in the neutrophils and the monocytes-macrophages which diffusely infiltrated in the sublining layer of rheumatoid synovium. In addition, the osteoclasts along subchondral bone were also intensively stained. The proMMP-9 concentration in joint fluids from 39 RA patients was positively correlated to the count of proMMP-9 positive cells in RA synovium (r=0.607) and to the score of diffuse infiltrates of lymphocytes (r=0.720). However, it did not show correlation to the stage and the class defined by Steinbrocker and to the other clinical laboratory data. Our results suggest that proMMP-9 actively participates in joint destruction of RA through the expression of neutrophils and monocytes-macrophages and is regulated by lymphocytes.     

Diagnosis of coronary vasospasm by detection of postischemic regional left ventricular delayed relaxation using echocardiographic evaluation with color kinesis

BACKGROUND: Coronary vasospasm has been diagnosed by invasive provocative procedures during coronary arteriography. It would be useful to have a reliable, noninvasive, and safe diagnostic method for coronary vasospasm. Regional left ventricular (LV) diastolic dysfunction may persist without systolic dysfunction after an episode of coronary vasospasm. Color kinesis (CK) has been recently developed to facilitate the echocardiographic evaluation of regional wall motion. HYPOTHESIS: Color kinesis may be useful for diagnosis of coronary vasospasm by detection of postischemic regional LV diastolic wall motion abnormality. METHODS: Fifty-one consecutive patients with the last chest symptom within 2 weeks (4 +/- 3 days) were studied echocardiographically. Regional fractional area change during the first 30% of LV filling time in percentage of the segmental end-diastolic area change (CK diastolic index) was used to identify diastolic endocardial motion asynchrony. RESULTS: After diagnostic coronary arteriography with spasm provocation, 26 patients were diagnosed with coronary spastic angina (CSA) and the other 25 with chest pain syndrome (CPS). Regional delayed relaxation (CK-diastolic index < or = 50%) or diastolic asynchrony had been observed in at least one region in 25 (96%) patients with CSA, whereas it had been noted in 2 (8%) patients with CPS. In 17 (65%) patients with CSA, it had been detected in multiple vascular territories, suggesting multivessel spasm. The diastolic asynchrony disappeared in CSA after a month of angina-free period. CONCLUSION: Analysis of CK images allows identification of regional LV delayed relaxation or diastolic asynchrony in patients with coronary vasospasm, differentiating them from patients with chest pain syndrome (sensitivity 96%, specificity 92%).     

Elevated Fibroblast Growth Factor 23 Exerts Its Effects on Placenta and Regulates Vitamin D Metabolism in Pregnancy of Hyp Mice

Fibroblast growth factor 23 (FGF23) functions in an endocrine fashion and requires α‐Klotho to exert its effects on the target organs. We have recently demonstrated that the human placenta also expresses α‐Klotho, which led us to hypothesize that FGF23 may exert effects on the placenta. Immunohistochemical analysis demonstrated the expression of FGF receptor 1 (FGFR1) as well as that of α‐Klotho in the feto‐maternal interface of both mouse and human normal‐term placentas, which suggested that these areas might be receptive to FGF23. Therefore, we next investigated whether FGF23 has some roles in the placenta using Hyp mice with high levels of circulating FGF23. Hyp and wild‐type (WT) females were mated with WT males, and the mothers and their male fetuses were analyzed. FGF23 levels in Hyp mothers were elevated. FGF23 levels were about 20‐fold higher in Hyp fetuses than in Hyp mothers, whereas WT fetuses from Hyp mothers exhibited low levels of FGF23, as did fetuses from WT mothers. We analyzed the placental gene expression and found that the expression of Cyp24a1 encoding 25OHD‐24‐hydroxylase, a target gene for FGF23 in the kidney, was increased in the placentas of fetuses from Hyp mothers compared with fetuses from WT mothers. In an organ culture of WT placentas, treatment with plasma from Hyp mothers markedly increased the expression of Cyp24a1, which was abolished by the simultaneous addition of anti‐FGF23 neutralizing antibody. The direct injection of recombinant FGF23 into WT placentas induced the expression of Cyp24a1. The increase in the placental expression of Cyp24a1 in fetuses from Hyp mothers resulted in decreased plasma 25‐hydroxyvitamin D levels. These results suggest that increased levels of circulating FGF23 in pathological conditions such as Hyp mice exerts direct effects on the placenta and affects fetal vitamin D metabolism via the regulation of Cyp24a1 expression. © 2014 American Society for Bone and Mineral Research.     

Enhanced heat shock protein 25 immunoreactivity in cranial nerve motoneurons and their related fiber tracts in rats prenatally‐exposed to X‐irradiation

Alterations in histoarchitecture of the brainstem were examined immunohistochemically in 4‐week‐old rats with a single whole body X‐irradiation at a dose of 0.5, 1.0, or 1.5 Gy on embryonic day (ED) 15 using anti‐heat shock protein 25 (HSP25). HSP25 immunostaining was seen in the neuronal perikarya of cranial nerve motoneurons, that is, the motor and mesencephalic nuclei of the trigeminal nerve, facial nucleus, abducens nucleus and accessory facial nucleus in the pons, and the ambiguous nucleus, dorsal nucleus of vagus nerve and hypoglossus nucleus in the medulla oblongata of intact controls. In 0.5 to 1.5 Gy‐irradiated rats, HSP25 immunostaining in those neurons was more intense than in controls, while the most intense immunostaining was marked in 1.5 Gy‐irradiated rats. HSP25 immunostaining was also apparent in the spinal tract of the trigeminal nerve and facial nerve tracts in 0.5 to 1.5 Gy‐irradiated rats, but was faint in controls. Interestingly, HSP25 immunostaining was aberrantly enhanced in dendritic arbors in the magnocellular region of medial vestibular nucleus of 0.5–1.5 Gy‐irradiated rats. Those arbors were identified as excitatory secondary vestibulo‐ocular neurons by double immunofluorescence for HSP25 and SMI‐32. The results suggest an increase of HSP25 expression in cranial nerve motoneurons and their related fiber tracts from prenatal exposure to ionizing irradiation. This may be an adaptive response to chronic hypoxia due to malformed brain arteries caused by prenatal ionizing irradiation.     

Leadless cardiac pacemaker implantations after infected pacemaker system removals in octogenarians

BackgroundManagement of pacemaker (PM) infections among advanced aged patients possesses particular clinical challenges due to higher rates of concurrent cardiovascular disease and medical comorbidities. Novel leadless cardiac pacemakers (LCPs) may provide new opportunities for better management options in this population, however, there is limited data especially in Asian populations to guide the decision making.MethodsWe reviewed 11 octogenarians (median age: 86 [minimum 82–maximum 90] years; male: 73%; median body mass index (BMI): 20.1 kg/m²) who received Micra Transcatheter Pacing System (Medtronic Inc, Minneapolis, MN) implantations following transvenous lead extractions (TLEs) for PM infections. ResultsAll patients had more than two medical comorbidities (average 3.7 comorbidities). The indications for LCP implantations were atrioventricular block in four patients, atrial fibrillation bradycardia in five, and sinus node dysfunction in two. Eight patients (73%) were bridged with temporary pacing using active fixation leads (median interval of 14.0 days), while one with severe dementia underwent a concomitant LCP implantation and TLE during the same procedure. Successful TLEs and LCP implantations were successfully accomplished in all without any complications. The median time from the TLE procedure to discharge was 22 days (minimum 7–maximum 136). All patients remained free of infections during a mean follow-up period of 17.2 ± 6.5 months.ConclusionsLCP implantations were safe and effective after removing the entire infectious PM system in all octogenarians. The novel LCP technology may offer an alternative option for considering a re-implantation strategy after transvenous PM infections in elderly patients, particularly those with severe frailty and PM dependency.

The incidence of cardiac pacemaker (PM) infections among patients with an advanced age has been increasing owing to the continually widening indications and growing number of generator replacements.^[1–3] In current clinical practice, there is a class l indication for removing all hardware in the case of a proven or suspected device infection, and after a recovery window, a new conventional PM is implanted in PM dependent patients.^[1,4,5] However, this management for the elderly population is one of the most sensitive issues, since they possess particular clinical challenges due to higher rates of concurrent cardiovascular disease and medical comorbidities.^[6–10]Recently, the implantation of a Micra Transcatheter Pacing System (Medtronic Inc, Minneapolis, MN) has emerged as a new option for PM re-implantations after the removal of infectious PMs.^[11–17] Without the use of leads and a device pocket, this leadless cardiac pacemaker (LCP) potentially reduces the risk of pocket infections and lead associated endocarditis.^[16,17] However, there have not been enough data supporting the feasibility of leadless PM implantations following the removal of infectious PMs in people with an older age, particularly in octogenarians. Furthermore, there has been no data regarding those therapeutic strategies in Asian populations who have a low body mass index (BMI) and are at a higher risk of a transvenous lead extraction (TLE) procedure. Therefore, in this case series, we sought to characterize the procedure for LCP implantations following TLEs of infected PMs in octogenarians at 2 Japanese high-volume centers.     

Delayed DNA Synthesis Induced by 3-Aminobenzamide in Partially Hepatectomized Liver of Rats

The possibility of poly(ADP-ribosyl)ation playing a role during liver regeneration induced by partial hepatectomy (PH) in vivo was examined. When rats were given an i.p. injection of 3-antinobenzamide (ABA) at a dose of 600 mg/kg body weight 12 h after PH, the levels of DNA synthesis at 20 h after PH were significantly reduced. The time course of DNA synthesis in regenerating liver was significantly delayed in the ABA-treated group. Enzymatic assay revealed the activity of poly-(ADP-ribose)polymerase (PADPRP) in controls to be increased in parallel with the increase of DNA synthesis induced by PH. This increase in PADPRP activity was delayed and very much weaker after ABA treatment. The results thus suggested that poly (AUP-ribosyl)ation might play an important role in DNA synthesis during liver regeneration in vivo.     

Longitudinal Analysis of Neutralizing Potency against SARS-CoV-2 in the Recovered Patients after Treatment with or without Favipiravir

The effect of treatment with favipiravir, an antiviral purine nucleoside analog, for coronavirus disease 2019 (COVID-19) on the production and duration of neutralizing antibodies for SARS-CoV-2 was explored. There were 17 age-, gender-, and body mass index-matched pairs of favipiravir treated versus control selected from a total of 99 patients recovered from moderate COVID-19. These subjects participated in the longitudinal (>6 months) analysis of (i) SARS-CoV-2 spike protein’s receptor-binding domain IgG, (ii) virus neutralization assay using authentic virus, and (iii) neutralization potency against original (WT) SARS-CoV-2 and cross-neutralization against B.1.351 (beta) variant carrying triple mutations of K417N, E484K, and N501Y. The results demonstrate that the use of favipiravir: (1) significantly accelerated the elimination of SARS-CoV-2 in the case vs. control groups (p = 0.027), (2) preserved the generation and persistence of neutralizing antibodies in the host, and (3) did not interfere the maturation of neutralizing potency of anti-SARS-CoV-2 and neutralizing breadth against SARS-CoV-2 variants. In conclusion, treatment of COVID-19 with favipiravir accelerates viral clearance and does not interfere the generation or maturation of neutralizing potency against both WT SARS-CoV-2 and its variants.