Predicting the Readmission and Mortality in Older Patients Hospitalized with Pneumonia with Preadmission Frailty

BACKGROUND

In older people, frailty has been recognized as an important prognostic factor. However, only a few studies have focused on multidimensional frailty as a predictor of mortality and readmission among inpatients with pneumonia.

OBJECTIVE

The present study aimed to assess the association between preadmission frailty and clinical outcomes after the hospitalization of older patients with pneumonia.

DESIGN

Single-center, retrospective case-control study.

SETTING

Acute phase hospital at Kobe, Japan.

PARTICIPANTS

The present study included 654 consecutive older inpatients with pneumonia.

MEASUREMENTS

Frailty status before admission was assessed using total Kihon Checklist (KCL) score, which has been used as a self-administered questionnaire to assess comprehensive frailty, including physical, social, and cognitive status. The primary outcome was a composited 6-month mortality and readmission after discharge.

RESULTS

In total, 330 patients were analyzed (median age: 79 years, male: 70.4%, median total KCL score: 10 points), of which 68 were readmitted and 10 died within 6 months. After multivariate analysis, total KCL score was associated with a composited 6-month mortality and readmission (adjusted hazard ratio, 1.07; 95% confidence interval, 1.02-1.12; p = 0.006). The cutoff value for total KCL score determined by receiver operating characteristic curve analysis was 15 points (area under the curve = 0.610). The group with a total KCL score ≥ 15 points had significantly higher readmission or mortality rates than the groups with a total KCL score < 15 points (p < 0.001).

CONCLUSIONS

Preadmission frailty status in older patients with pneumonia was an independent risk factor for readmission and survival after hospitalization.

Alleviative effects of glutamate against chemotherapeutic agent-induced intestinal mucositis

5-Fluorouracil (5-FU) is one of the most widely used chemotherapeutic agents; however, it often causes intestinal mucositis with severe diarrhea. An efficient treatment strategy to reduce this side effect is lacking. Glutamate (Glu), a nonessential amino acid, is the most important energy source in the small intestine and has been shown to maintain intestinal morphology, barrier function, and antioxidative capacity. However, the effects of Glu on intestinal mucositis induced by chemotherapeutic agents have not been explored. This study aimed to demonstrate the alleviative effects of Glu on 5-FU-induced intestinal mucositis. Mucositis was induced in C57B/6N mice by intraperitoneal injection of 5-FU (50 mg/kg) for 6 days and assessed by histological and physiological analyses. Glu (500 or 1000 mg/kg) was orally administered as a pretreatment twice daily for 7 days before the initial treatment of 5-FU. Cellular proliferation and apoptosis were assessed using Ki-67 immunostaining and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, respectively. Furthermore, fluorescein isothiocyanate-dextran infiltration was assessed to measure intestinal permeability. In vitro experiments using rat intestinal epithelial cells (IEC-6 cells) were performed to clarify the effect of Glu on 5-FU-induced barrier dysfunction. Glu alleviated 5-FU-induced intestinal mucositis by reducing villi shortening, enhancing cell proliferation, and suppressing apoptosis. It also alleviated the 5-FU-induced increased intestinal permeability. In vitro studies revealed significantly increased trans-epithelial electrical resistance (TEER) in Glu-pretreated IEC-6 cells compared to that in 5-FU-treated and control cells. In conclusion, the findings of this study provide evidence for the potential of Glu to protect against 5-FU-induced intestinal mucositis in patients with cancer.

Prognostic significance of 2019 Asian Working Group for Sarcopenia update on definition of sarcopenia

Background/Introduction

Sarcopenia plays a major role in the pathophysiology of frailty and is associated with worse outcome in the elderly population including patients with heart failure. A recent update of the most common definition of sarcopenia in Asia, Asian Working Group for Sarcopenia (AWGS2019), included significant changes in the diagnostic algorithm with newly dividing sarcopenia into severe and “non-severe” sarcopenia.

Purpose

The objective of this study was to evaluate the differences between AWGS2014 and AWGS2019 in patients with heart failure.

Methods

In the multicenter prospective FRAGILE-HF registry, which included elderly (≥65 years old) patients who were hospitalized with heart failure, we studied 865 patients (80±8 years old, 42% female). All-cause death in 1-year follow-up was tracked.

Results

Based on the original version of AWGS (AWGS2014), 183 patients (21%) were diagnosed with sarcopenia, which was associated with higher age, lower physical performance, less muscle mass, and greater heart failure risk (all p&lt;0.001) as well as higher rate of all-cause death (HR 1.90, p=0.004 after adjustment by multivariable regression). Those patients with sarcopenia by AWGS2014 were reclassified mainly to severe sarcopenia (155, 84.7%) by AWGS2019, and 25 (13.7%) and 2 (1.1%) were classified into sarcopenia and non-sarcopenia. Meanwhile, 24 (3.5%) and 4 (0.6%) of patients without sarcopenia by AWGS2014 were reclassified into sarcopenia and severe sarcopenia, respectively. Although severe sarcopenia by AWGS2019 was associated with higher age, lower physical performance, less muscle mass, and greater heart failure risk (all p&lt;0.001), patients with “non-severe” sarcopenia was rather younger (p&lt;0.001) and had better physical performance (p=0.021) despite less muscle mass (p&lt;0.001) than those without sarcopenia. Multivariate Cox analysis demonstrated severe sarcopenia by AWGS2019 was an independent prognostic factor (HR 1.77, p=0.014), but “non-severe” sarcopenia was not (HR 1.52, p=0.37). The prognosis of patients who were reclassified from non-sarcopenia to sarcopenia or severe sarcopenia were comparable to those remained non-sarcopenia. When added to other risk factors, the prognostic predictability of AWGS2019 was significantly lower than AWGS2014 (net reclassification improvement −0.26, p=0.025).

Conclusions

About a half of “non-severe” sarcopenia in AWGS2019 were patients without sarcopenia in AWGS2014. The prognosis of such patients who were newly diagnosed as sarcopenia was good, resulting in low overall prognostic predictability of AWGS2019. A further consideration for diagnostic algorithms of sarcopenia may be warranted in patients with heart failure.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Japan Heart Foundation

Social frailty provides additive prognostic impact on one-year outcome in aged patients with congestive heart failure

Background

Frailty is associated with multisystem declines in physiologic reserve and increased vulnerability to stressors, resulting in increased risks of adverse clinical outcomes in patients with heart failure (HF). Although frailty is conceptualized as an accumulation of deficits in multiple areas, most of the studies have focused mainly on physical frailty, and the social domains is one of the least investigated area.

Objectives

We prospectively evaluated the incidence and prognostic implication of social frailty (SF) in older patients with HF.

Methods

The FRAGILE-HF is a multicenter, prospective cohort study including patients hospitalized for HF and aged ≥65 years old. We defined SF by Makizako's 5 items, which are 5 questions proposed and validated to be associated with future disability. The primary endpoint of this study was a composite of death from any cause and rehospitalization due to HF. The impact of SF on all-cause mortality alone was also evaluated.

Results

Among 1,240 hospitalized HF patients, 5 simple questions revealed that 825 (66.5%) were in SF. During 1-year observation period after the discharge, the combined endpoint was observed in 399 (32.2%) patients, and 145 (11.7%) patients died. Kaplan-Meier analysis showed that SF patients had significantly higher rates of both the combined endpoint and all-cause mortality than those without SF (Log-rank test: p&lt;0.05 for both, Figures). Moreover, SF remained independently associated with higher event rate of the combined endpoint (hazard ratio: 1.30; 95% confidence interval: 1.02 to 1.66; p=0.038) and all-cause mortality (hazard ratio: 1.53; 95% confidence interval: 1.01 to 2.30; p=0.044), even after adjusting for other covariates. Significant incremental prognostic value was shown when information on social frailty was added to known risk factors for combined endpoint (NRI: 0.189, 95% confidence interval: 0.063–0.316, p=0.003) and all-cause mortality (NRI: 0.234, 95% confidence interval: 0.073–0.395, p=0.004).

Conclusions

Among older hospitalized patients with heart failure, two-thirds of the population was with SF. Evaluating SF provides additive prognostic information in elderly patients with heart failure.

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Novartis Pharma Research Grants, Japan Heart Foundation Research Grant

Intrinsic reconstruction of ice-I surfaces

Understanding the precise atomic structure of ice surfaces is critical for revealing the mechanisms of physical and chemical phenomena at the surfaces, such as ice growth, melting, and chemical reactions. Nevertheless, no conclusive structure has been established. In this study, noncontact atomic force microscopy was used to address the characterization of the atomic structures of ice Ih(0001) and Ic(111) surfaces. The topmost hydrogen atoms are arranged with a short-range (2 × 2) order, independent of the ice thickness and growth substrates used. The electrostatic repulsion between non-hydrogen-bonded water molecules at the surface causes a reduction in the number of the topmost hydrogen atoms together with a distortion of the ideal honeycomb arrangement of water molecules, leading to a short-range-ordered surface reconstruction.

The Evolution of Neuroscience as a Research Field Relevant to Dentistry

The field of neuroscience did not exist as such when the Journal of Dental Research was founded 100 y ago. It has emerged as an important scientific field relevant to dentistry in view of the many neurally based functions manifested in the orofacial area (e.g., pain, taste, chewing, swallowing, salivation). This article reviews many of the novel insights that have been gained through neuroscience research into the neural basis of these functions and their clinical relevance to the diagnosis and management of pain and sensorimotor disorders. These include the neural pathways and brain circuitry underlying each of these functions and the role of nonneural as well as neural processes and their "plasticity" in modulating these functions and allowing for adaptation to tissue injury and pain and for learning or rehabilitation of orofacial functions.

Involvement of transient receptor potential vanilloid 2 in intra-oral incisional pain

OBJECTIVE

To examine whether transient receptor potential vanilloid 2 (TRPV2) contributes to the changes in intra-oral thermal and mechanical sensitivity following the incision of buccal mucosa.

MATERIALS AND METHODS

Buccal mucosal pain threshold was measured after the incision. Changes in the number of TRPV2-immunoreactive (IR) trigeminal ganglion (TG) neurons which innervate the whisker pad skin and buccal mucosa, changes in the number of isolectin B4-negative/isolectin B4-positive TRPV2-IR TG neurons which innervate the whisker pad skin and the buccal mucosa, and the effect of peripheral TRPV2 antagonism on the pain threshold of incisional whisker pad skin and buccal mucosa were examined after these injuries.

RESULTS

Buccal mucosal pain hypersensitivities were induced on day 3 following the incision. The total number of TRPV2-IR TG neurons and the number of isolectin B4-negative TRPV2-IR TG neurons which innervate the whisker pad skin and buccal mucosa were increased. Buccal mucosal TRPV2 antagonism completely suppressed the heat and mechanical hypersensitivities, but not cold hypersensitivity. TRPV2 antagonist administration to the incisional whisker pad skin only partially suppressed pain hypersensitivities.

CONCLUSION

The increased expression of TRPV2 in peptidergic TG neurons innervating the incisional buccal mucosa is predominantly involved in buccal mucosal heat hyperalgesia and mechanical allodynia following buccal mucosal incision.

Shorter duration of antibiotic treatment for acute bacteraemic cholangitis with successful biliary drainage: a retrospective cohort study

OBJECTIVES

To assess the effectiveness of short duration antimicrobial therapy for acute cholangitis with bacteraemia.

METHODS

We conducted a retrospective cohort study of patients with acute bacteraemic cholangitis with successful biliary duct drainage at a single centre in Japan. We compared short-course antimicrobial therapy (SCT, ≤7 days) and long-course therapy (LCT, ≥8 days), with a primary outcome of 30-day mortality. We constructed logistic regression models for mortality and a composite outcome, including mortality, recurrence, recrudescence, new bacteraemia, liver abscess or other complications related to cholangitis. We also developed a propensity score for SCT with inverse probability weighting for both the primary outcome and the composite outcome.

RESULTS

We identified 263 patients in our cohort; 86 (32.7%) patients received SCT and the remaining 177 (67.3%) received LCT. The median durations of SCT and LCT were 6 days (range 2-7 days) and 12 days (range 8-46 days), respectively. The 30-day mortalities of SCT and LCT were 4.7% (4/85) and 5.7% (10/176), respectively (p 1.00). Logistic regression analysis showed that the odds ratio of SCT for 30-day mortality and the composite outcome were 1.07 (95% CI 0.25-4.52, p 0.93) and 1.08 (95% CI 0.48-2.45, p 0.85), respectively. Propensity score analyses for both 30-day mortality and the composite outcome did not demonstrate a difference between SCT and LCT (p 0.65 and p 0.95, respectively).

CONCLUSIONS

SCT with a median duration of 6 days did not have worse outcomes than LCT with a median duration of 12 days. Shortening the duration of antimicrobial therapy may be a reasonable option when treating acute bacteraemic cholangitis following successful biliary drainage.

Differentiation of Physiological States under Sensory Deprivation

We attempt to differentiate the physiological state during sensory deprivation (SD) from normal sleep and wakefulness in terms of electroencephalogram (EEG) and heart rate variability (HRV) dynamics. KullbackLeibler (K-L) divergence is employed to quantify differences between their state-dependent dynamics. As a result, the dynamics of EEG and HRV during SD are found to be far distant from any representative dynamics of natural states of sleep and wakefulness. However, relatively speaking, the findings in SD can be categorized into two patterns. (a) The dynamics of HRV during SD is similar to that of rapid eye movement (REM) sleep, and the dynamics of EEG during SD is similar to that of wakefulness. (b) The dynamics of both HRV and EEG during SD are similar to that of REM. Such dissociation between states classified by EEG and HRV dynamics frequently takes place during SD. These findings suggest the peculiarity of the physiological state during the SD distinct from sleep and wakefulness.

The effect of regioisomerism on the photophysical properties of alkylated-naphthalene liquids

Novel alkylated naphthalene liquids with a correlation among the 1- and 2-regioisomeric chemical structures and their photophysical, calorimetric and rheological properties are presented.

Role of Neuron-Glial Interaction Mediated by IL-1β in Ectopic Tooth Pain

Although many reports have demonstrated that ectopic pain develops in the orofacial region following tooth pulp inflammation, which often causes misdiagnosis and inappropriate treatment for patients with pulpitis, the precise mechanism remains unknown. In the present study, we hypothesized that the functional interaction between satellite glial cells and neurons mediated by interleukin 1β (IL-1β) in the trigeminal ganglion (TG) is involved in ectopic orofacial pain associated with tooth pulp inflammation. The digastric muscle electromyogram (D-EMG) activity elicited by capsaicin administration into the maxillary second molar tooth pulp was analyzed to evaluate the noxious reflex and was significantly increased in rats with inflammation of the maxillary first molar (M1) versus rats injected with saline. A significant increase in the expression of connexin43 (Cx43), a gap junction containing protein, was observed in activated satellite glial cells surrounding second molar-innervating neurons in the TG after M1 pulpitis. Daily administration of Gap26, a Cx43 mimetic peptide and inhibitor, in the TG significantly suppressed the enhancement of capsaicin-induced D-EMG activity and the percentage of Fluoro-Gold (FG)-labeled cells encircled by glial fibrillary acid protein-immunoreactive (IR) + Cx43-IR cells after M1 pulp inflammation ( P < 0.01). The percentage of FG-labeled cells encircled by glial fibrillary acid protein-IR + IL-1β-IR cells, IL-1 type I receptor-IR cells labeled with FG, and TRPV1-IR cells labeled with FG significantly increased after M1 pulp inflammation ( P < 0.01). Daily administration of IL-1ra, an IL-1 receptor antagonist, into the TG significantly reduced the enhancement of capsaicin-induced D-EMG activity and the percentage of TRPV1-IR neurons labeled with FG after M1 pulp inflammation ( P < 0.01). The present findings suggest that satellite glial cell is activated in the TG via activated gap junctions composed of Cx43 following tooth pulp inflammation, which leads to the hyperactivation of remote neurons via IL-1β mechanisms and results in ectopic tooth pulp pain in the adjacent tooth.

Maternal Separation Induces Orofacial Mechanical Allodynia in Adulthood

It is well known that exposure to maternal separation (MS) in early life causes plastic changes in the nervous system in adulthood, occasionally resulting in ubiquitous chronic pain. However, the pathogenic mechanisms of pain hypersensitivity remain unclear. Here, the authors examined the involvement of corticosterone in orofacial mechanical hypersensitivity induced by MS. To establish a rat model of MS, pups were placed in isolated cages 180 min/d and kept in a temperature-controlled environment at 22 ± 2 °C for 14 d. Mechanical allodynia in the whisker pad skin in adulthood was induced by MS and was significantly suppressed by successive postnatal subcutaneous administration of the glucocorticoid receptor antagonist mifepristone. Corticosterone levels were increased in the serum of MS rats, and successive postnatal administration of subcutaneous corticosterone to naive rats induced mechanical allodynia in the whisker pad skin. The number of P2X3 receptor-immunoreactive (P2X3R-IR) trigeminal ganglion (TG) neurons innervating the whisker pad skin was significantly increased in MS rats and decreased following subcutaneous administration of mifepristone. The number of P2X3R-IR TG neurons innervating the whisker pad skin was also significantly increased following successive postnatal administration of subcutaneous corticosterone in naive rats. Moreover, the mechanical allodynia was suppressed 30 min after administration of the P2X3R antagonist A317491 to the whisker pad skin in MS rats. These findings suggest that the increase in P2X3R-IR TG neurons innervating the whisker pad skin via enhanced neonatal corticosterone signaling by MS plays an important role in orofacial mechanical allodynia in adulthood.

Pathology of spinal cord lesions caused by ossification of the posterior longitudinal ligament, with special reference to reversibility of the spinal cord lesion

This report describes pathological findings of the spinal cord damage, with ossification of the posterior longitudinal ligament (OPLL), with special reference to reversibility of such lesions. Twenty-five autopsy cases associated with OPLL were examined, and the spinal cord damage was pathologically classified into four categories based on degree of destruction (stage 0-3). In stage 0 and stage 1, major pathological changes in the gray matter and the degree of compression on the spinal cord were well correlated to deformity of the anterior horn. In stage 2 and stage 3, neurons were almost completely obliterated and necrosis with cavitation were frequently observed. Destruction of the spinal cord in stage 2 and stage 3 is considered to be irreversible; therefore, surgical treatment is recommended at stage 0 or stage 1.

Involvement of Microglial P2Y12 Signaling in Tongue Cancer Pain

To elucidate if microglial P2Y12 receptor (P2Y12R) mechanisms are involved in the trigeminal spinal subnucleus caudalis (Vc; also known as the medullary dorsal horn) in intraoral cancer pain, we developed a rat model of tongue cancer pain. Squamous cell carcinoma (SCC) cells were inoculated into the tongue of rats; sham control rats received the vehicle instead. Nociceptive behavior was measured as the head-withdrawal reflex threshold (HWRT) to mechanical or heat stimulation applied to the tongue under light anesthesia. On day 14 after the SCC inoculation, activated microglia and P2Y12R expression were examined immunohistochemically in the Vc. The HWRT was also studied in SCC-inoculated rats with successive intra-cisterna magna (i.c.m.) administration of specific P2Y12R antagonist (MRS2395) or intraperitoneal administration of minocycline, a microglial activation inhibitor. Tongue cancer was histologically verified in SCC-inoculated rats, within which the HWRT to mechanical stimulation of the tongue was significantly decreased, as compared with that of vehicle-inoculated rats, although the HWRT to heat stimulation was not. Microglia was strongly activated on day 14, and the administration of MRS2395 or minocycline reversed associated nocifensive behavior and microglial activation in SCC-inoculated rats for 14 d. The activity of Vc wide dynamic range nociceptive neurons was also recorded electrophysiologically in SCC-inoculated and sham rats. Background activity and noxious mechanically evoked responses of wide dynamic range neurons were significantly increased in SCC-inoculated rats versus sham rats, and background activity and mechanically evoked responses were significantly suppressed following i.c.m. administration of MRS2395 in SCC-inoculated rats as compared with sham. The present findings suggest that SCC inoculation that produces tongue cancer results in strong activation of microglia via P2Y12 signaling in the Vc, in association with increased excitability of Vc nociceptive neurons, reflecting central sensitization and resulting in tongue mechanical allodynia.

The validity of three sputum smears taken in one day for discontinuing isolation of tuberculosis patients

We conducted a retrospective comparative study of acid-fast bacilli (AFB) smear sensitivity according to time of specimen collection to assess whether three consecutive AFB smears collected in 1 day are useful when deciding to discontinue respiratory isolation of patients with pulmonary tuberculosis (TB). A total of 236 sputum specimens from 119 patients with pulmonary TB were used for the analysis. There was no statistical difference in AFB smear sensitivity of early-morning sputum and those collected later (P = 0.186). This may allow us to collect all specimens in a single day and discontinue respiratory isolation of TB patients earlier.

Involvement of TRPV1 and TRPA1 in incisional intraoral and extraoral pain

Thermal and mechanical hypersensitivity in the injured region is a common complication. Although it is well known clinically that thermal and mechanical sensitivity of the oral mucosa is different from that of the skin, the mechanisms underlying injured pain of the oral mucosa remain poorly understood. The transient receptor potential (TRP) vanilloid 1 (TRPV1) and TRP ankyrin 1 (TRPA1) in primary afferent neurons are known to contribute to pathological pain. Therefore, we investigated whether TRPV1 and/or TRPA1 contribute to thermal and mechanical hypersensitivity following oral mucosa or whisker pad skin incision. Strong heat and mechanical and cold hypersensitivity was caused in the buccal mucosa and whisker pad skin following incisions. On day 3 after the incisions, the number of TRPV1-immunoreactive (IR) and TRPA1-IR trigeminal ganglion (TG) neurons innervating the buccal mucosa and whisker pad skin was significantly increased, and the number of TRPV1/TRPA1-IR TG neurons innervating whisker pad skin, but not the buccal mucosa, was significantly increased. Administration of the TRPV1 antagonist, SB366791, to the incised site produced a significant suppression of heat hyperalgesia in both the buccal mucosa and whisker pad skin, as well as mechanical allodynia in the whisker pad skin. Administration of the TRPA1 antagonist, HC-030031, to the incised site suppressed mechanical allodynia and cold hyperalgesia in both the buccal mucosa and whisker pad skin, as well as heat hyperalgesia in the whisker pad skin. These findings indicate that altered expressions of TRPV1 and TRPA1 in TG neurons are involved in thermal and mechanical hypersensitivity following the buccal mucosa and whisker pad skin incision. Moreover, diverse changes in the number of TRPV1 and TRPA1 coexpressed TG neurons in whisker pad skin-incised rats may contribute to the intracellular interactions of TRPV1 and TRPA1 associated with whisker pad skin incision, whereas TRPV1 and TRPA1 expression in individual TG neurons is involved in buccal mucosa-incised pain.

Morphological and functional changes in regenerated primary afferent fibres following mental and inferior alveolar nerve transection

BACKGROUND

It is important to know the mechanisms underlying pain abnormalities associated with inferior alveolar nerve (IAN) regeneration in order to develop the appropriate treatment for orofacial neuropathic pain patients. However, peripheral mechanisms underlying orofacial pain abnormalities following IAN regeneration are not fully understood.

METHODS

Head withdrawal threshold (HWT), jaw opening reflex (JOR) thresholds, single-fibre recordings of the regenerated mental nerve (MN) fibres, calcitonin gene-related peptide (CGRP), isolectin B4 (IB4), peripherin, neurofilament-200 (NF-200) and transient receptor potential vanilloid 1 (TRPV1) expression in trigeminal ganglion (TG) cells, and electron microscopic (EM) observations of the regenerated MN fibres were studied in MN- and IAN-transected (M-IANX) rats.

RESULTS

HWT to mechanical or heat stimulation of the mental skin was significantly lower in M-IANX rats compared with sham rats. Mean conduction velocity of action potentials recorded from MN fibres (n = 124) was significantly slower in M-IANX rats compared with sham rats. The percentage of Fluoro-Gold (FG)-labelled CGRP-, peripherin- or TRPV1-immunoreactive (IR) cells was significantly larger in M-IANX rats compared with that of sham rats, whereas that of FG-labelled IB4- and NF-200-IR cells was significantly smaller in M-IANX rats compared with sham rats. Large-sized myelinated nerve fibres were rarely observed in M-IANX rats, whereas large-sized unmyelinated nerve fibres were frequently observed and were aggregated in the bundles at the distal portion of regenerated axons.

CONCLUSIONS

These findings suggest that the demyelination of MN fibres following regeneration may be involved in peripheral sensitization, resulting in the orofacial neuropathic pain associated with trigeminal nerve injury.

Early and late outcomes after reoperation for prosthetic valve endocarditis

OBJECTIVE

Prosthetic valve endocarditis remains a challenging complication after heart valve replacement. To identify predictive risk factors, we have reviewed 30 patients who underwent surgery for prosthetic valve endocarditis between March 1986 and May 1999.

METHODS

There were 15 men and 15 women (mean age 51 years). Prosthetic valve endocarditis was classified as early (< or = 1 year after operation) in 10 cases, and as late in the other 20 cases. The most common indication for surgery was moderate to severe congestive heart failure due to prosthetic valve dysfunction in 21 (70%) patients. The average follow-up period was 6.5 years, with a range of 0.3 to 14.1 years.

RESULTS

The most common microorganism was Staphylococcus epidermidis in both patients with early (50%) and late prosthetic valve endocarditis (25%). The in-hospital mortality was 13.3% (4/30). There were six late deaths. The actuarial survival at 5 years was 78% and 66% at 10 years. An early onset of prosthetic valve endocarditis was the only significant determinant of both in-hospital mortality (p = 0.005) and overall mortality (p = 0.021). Emergency surgery had a statistically significant relationship with in-hospital mortality (p = 0.045). No significant influence on mortality after reoperation for prosthetic valve endocarditis was found in age, sex, valve position, antecedent native valve endocarditis, or in the type of pathological findings (ring abscess, valve dehiscence, and vegetation).

CONCLUSION

Early onset of prosthetic valve endocarditis and emergency surgery were important risk factors for mortality due to prosthetic valve endocarditis.

Hardening and termination of long-duration γ rays detected prior to lightning

We report the first observation of 3-30 MeV prolonged gamma-ray emission that was abruptly terminated by lightning. The gamma-ray detection was made during winter thunderstorms on December 30, 2010, by the Gamma-Ray Observation of Winter Thunderclouds experiment carried out in a coastal area along the Sea of Japan. The gamma-ray flux lasted for less than 3 min, continuously hardening closer to the lightning occurrence. The hardening at energies of 3-10 MeV energies was most prominent. The gamma-ray flux abruptly ceased less than 800 ms before the lightning flash that occurred over 5 km away from the experimental site. In addition, we observed a clear difference in the duration of the 3-10 MeV gamma rays and those >10 MeV, suggesting that the area of >10 MeV gamma-ray emission is considerably smaller than that of the lower-energy gamma rays. This work may give a manifestation that a local region emitting prolonged gamma rays connects with a distant region to initiate lightning.

Interaction of IL-1β and P2X(3) receptor in pathologic masseter muscle pain

The exact mechanism underlying chronic masseter muscle pain, a conspicuous symptom in temporomandibular disorder, remains unclear. We investigated whether expression of P2X3 receptor (P2X3R) is involved in mechanical hyperalgesia after contraction of masseter muscle (CMM). As compared with sham rats, the head-withdrawal threshold (HWT) to mechanical pressure stimulation of masseter muscle (MM) (but not after similar stimulation of facial skin) was significantly lower, and IL-1β level was significantly higher, in CMM rats on day 7 after CMM. The mean percentage of FG-labeled P2X3R-positive neurons was significantly increased in TG following successive IL-1β injections into the MM for 7 days. Successive administration of an IL-1β receptor-antagonist into the MM attenuated the increase of P2X3-IR cells in the TG. ATP release from MM after 300-g pressure stimulation of MM was also significantly enhanced after CMM. Administration into MM of the selective P2X3,2/3 receptor antagonist A-317491 attenuated the decrement of HWT in CMM rats. A significant increase in HWT was also observed at 30 min after A-317491 (60 µg) injection in IL-1β-injected rats. These findings suggest that P2X3R expression associated with enhanced IL-1β expression and ATP release in MM has a possible important role in MM mechanical hyperalgesia after excessive muscular contraction.

Levels of the oxidative stress marker γ-glutamyltranspeptidase at different stages of nonalcoholic fatty liver disease

OBJECTIVES

This study investigated oxidative stress in the liver, by determining hepatic expression and serum levels of γ-glutamyltranspeptidase (GGT) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in different stages of nonalcoholic fatty liver disease (NAFLD), and assessed whether GGT can differentiate between the various stages of NAFLD.

METHODS

Expression of GGT and 8-OHdG was examined in biopsy specimens by immunohistochemistry, and serum GGT and 8-OHdG levels were measured by enzyme-linked immuno sorbent assays in patients with simple fatty liver (n = 10), nonalcoholic steatohepatitis (NASH; n = 10) and, as a control, in alcoholic liver disease (ALD; n = 10).

RESULTS

Hepatic tissue expression of GGT and 8-OHdG was seen in ALD, NASH and fatty liver patients. The percentage of hepatocytes positive for 8-OHdG expression and serum 8-OHdG levels was significantly higher in patients with NASH than simple fatty liver. Serum GGT levels were increased in all cases with ALD, NASH and fatty liver, and correlated significantly with serum levels of 8-OHdG in ALD and NASH, but not in simple fatty liver.

CONCLUSIONS

Levels of GGT in fatty liver patients may compensate for mild oxidative stress by repressing 8-OHdG levels and preventing progression to NASH; however further oxidative stress leads to increased levels of 8-OHdG and the development of NASH.

ERK is Involved in Tooth-pressure-induced Fos Expression in Vc Neurons

Discomfort and pain encountered during orthodontic treatment are major problems for patients, but the details of the underlying neural processes and molecular mechanisms are not well-understood. Here we show that noxious tooth mechanical pressure induced by orthodontic elastics resulted in a rapid and transient activation of extracellular signal-regulated protein kinase (ERK) in the trigeminal spinal subnucleus interpolaris and caudalis transition zone (Vi/Vc), trigeminal spinal subnucleus caudalis (Vc), and upper cervical spinal cord (Vc/C2). The phosphorylated ERK (pERK) was observed in neurons but not in astroglia and microglia. Single-plane scanning analysis indicated that the pERK was localized to the nucleus of Vc neurons. In addition, the tooth mechanical pressure led to Fos expression in the pERK-positive Vc neurons that would be suppressed by intrathecal administration of an MEK1/2 inhibitor (PD98059). Taken together, these findings suggest that activation of the ERK signaling cascade following noxious mechanical pressure on the teeth regulates Fos expression in Vc neurons and may thereby contribute to pain associated with orthodontic treatment.

Oestrogen-dependent suppression of pulsatile luteinising hormone secretion and kiss1 mRNA expression in the arcuate nucleus during late lactation in rats

Follicular development and ovulation are strongly suppressed during lactation in mammals via a profound suppression of gonadotrophin secretion. The present study aimed to examine the role of oestrogen feedback action in suppressing luteinising hormone (LH) secretion and hypothalamic kisspeptin expression during the latter half of lactation. Plasma LH concentrations kept at low levels throughout the lactating period in intact and oestrogen-replaced ovariectomised (OVX) lactating rats, whereas plasma LH concentrations gradually elevated from day 10 postpartum in lactating OVX rats. OVX lactating rats showed frequent LH pulses at late lactation, although the LH pulses were significantly inhibited by an oestrogen replacement, which is much less effective on LH release in nonlactating rats. Oestrogen replacement in lactating OVX rats significantly reduced the number of Kiss1 mRNA-expressing cells in the arcuate nucleus (ARC) at late lactation, although the same oestrogen treatment did not affect the number of Kiss1-expressing cells in nonlactating controls. Exogenous kisspeptin challenge (0.2 nmol) into the third cerebroventricle significantly increased LH secretion in lactating OVX, lactating OVX + subcutaneous 17β-oestradiol and intact lactating rats at day 16 postpartum. These results suggest that LH pulse suppression during late lactation could be a result of the enhanced oestrogen-dependent suppression of ARC kisspeptin expression.

Thermodynamic and kinetic processes during the unfolding of BSA in the presence of the mycotoxin patulin

The effects of the mycotoxin patulin on the thermodynamics and kinetics of the transition of bovine serum albumin (BSA) in aqueous solution were studied by Differential Scanning Calorimetry and Photoluminescence methods. Results show that in the presence of patulin, the free enthalpy change during the transition of BSA was decreased by an average of ∼ 46 kJ/mol, the free energy change was decreased by ∼ 4 kJ/mol, and the activation energy fell from ∼ 1546 to ∼ 840 kJ/mol. These results indicate that the bioactivity of patulin is based on the kinetic rather than on the thermodynamic properties of the transition. This is the first evidence of the direct interaction of patulin with the free thiol-containing BSA, a process which could contribute to the adverse cyto- and genotoxic effects induced by patulin.