Evidence for Enhanced Cytoprotective Function of HSP90-Overexpressing Small Intestinal Epithelial Cells

Background  

In the clinical field, increasing incidence of small intestinal ulcers associated with nonsteroidal anti-inflammatory drugs (NSAIDs) has become a topic with the advances of capsule endoscopy and balloon enteroscopy technology for the detection of small intestinal lesions. However, the pathogenesis of NSAID-induced mucosal damage, defensive mechanism of intestinal epithelial cells, and therapy for small intestinal mucosal lesion have not been fully understood. Heat shock proteins (HSPs) are involved in cytoprotection mediated by their function as a molecular chaperone. Since the function of HSP90 in the intestinal epithelial cells has not been well investigated, we examined the cytoprotective ability of HSP90-overexpressing small intestinal epithelial cells against hydrogen peroxide-induced or indomethacin-induced cell damage.     

White matter hyperintensities in patients with multiple system atrophy

IntroductionAlthough white matter hyperintensities (WMHs) are prevalent in the elderly, the clinical significance and the underlying pathophysiological mechanisms of WMHs in neurodegenerative disorders have not been fully clarified.ObjectiveThe present study aimed to determine the degree of WMHs in patients with multiple system atrophy (MSA), and analyze the predisposing factors for WMHs.MethodsTwo raters blinded to clinical information assessed cerebrovascular lesions in brain MRIs from patients with MSA and age-matched controls. Patients with Parkinson’s disease (PD) were similarly studied as a disease control. The results obtained were compared with the clinical characteristics of the patients and statistically analyzed.ResultsWMHs in patients with MSA were statistically greater compared with PD patients or controls. There were no significant differences in either lacunar or territorial infarcts. Multiple linear regression analysis demonstrated that age, supine systolic blood pressure, and a drop in orthostatic blood pressure were significantly and independently correlated with WMH scores in MSA.ConclusionsThe present study suggests that white matter is differentially involved in MSA. In addition to aging, cerebral hypoperfusions caused by fluctuations of blood pressure may be a significant contributing factor to WMHs in MSA, although the possibility that degenerative processes occurring in oligodendrocytes may be associated with WMHs should not be excluded.     

Weak association between sleep bruxism and obstructive sleep apnea. A sleep laboratory study

Purpose

No definitive associations or causal relationships have been determined between obstructive sleep apnea-hypopnea (OSAH) and sleep bruxism (SB). The purpose of this study was to investigate, in a population reporting awareness of both OSAH and SB, the associations between each specific breathing and jaw muscle event.

Methods

Polysomnography and audio–video data of 59 patients reporting concomitant OSAH and SB history were analyzed. Masseteric bursts after sleep onset were scored and classified into three categories: (1) sleep rhythmic masticatory muscle activity with SB (RMMA/SB), (2) sleep oromotor activity other than RMMA/SB (Sleep-OMA), and (3) wake oromotor activity after sleep onset (Wake-OMA).

Spearman’s rank correlation coefficient analyses were performed. Dependent variables were the number of RMMA/SB episodes, RMMA/SB bursts, Sleep-OMA, and Wake-OMA; independent variables were apnea-hypopnea index (AHI), arousal index(AI), body mass index(BMI), gender, and age.

Results

Although all subjects had a history of both SB and OSAH, sleep laboratory results confirmed that these conditions were concomitant in only 50.8 % of subjects. Moderate correlations were found in the following combinations (p?<?0.05); RMMA/SB episode with AI, RMMA/SB burst with AI and age, Sleep-OMA burst with AHI, and Wake-OMA burst with BMI.

Conclusions

The results suggest that (1) sleep arousals in patients with concomitant SB and OSAH are not strongly associated with onset of RMMA/SB and (2) apnea-hypopnea events appear to be related to higher occurrence of other types of sleep oromotor activity, and not SB activity. SB genesis and OSAH activity during sleep are probably influenced by different mechanisms.

     

Association of 72-kDa Heat Shock Protein Expression with Adaptation to Aspirin in Rat Gastric Mucosa

It is well documented that gastric mucosa canincrease its resistance to mucosal damage caused byaspirin during repeated long-term administration ofaspirin. However, the underlying mechanism of thisadaptation is not well established. In the present study,we investigated the effect of long-term (chronic)administration of aspirin on expression of heat shockproteins (HSPs), which are known as endogenouscytoprotectants, in rat gastric mucosa. Rats were administeredaspirin (100 mg/kg) daily for up to 20 days. Aftervarious periods of aspirin administration, a high doseof aspirin (250 mg/kg) was administered, and the mucosal damage was assessed. Expression of heat shockproteins (HSPs) in gastric mucosa was evaluated byWestern blot. Intracellular localization of each HSP wasstudied immunohistochemically. ProstaglandinE₂ (PGE₂) and leukotriene B₄(LTB₄) levels were also investigated.Long-term aspirin administration resulted in developmentof resistance to aspirin-induced mucosal damage, and theincrease of HSP72 expression correlated with mucosal resistance to aspirin.No significant increase was observed in HSP60 and HSP90levels. Immunohistochemical study showed an increase ofHSP72 in the cytoplasm of mucosal surface cells. The PGE₂ level was suppressed and nochange in the level of LTB₄ was observed. Itis possible that HSP72 could play important roles ingastric mucosal adaptation when the PGE₂level is suppressed by NSAIDs.     

Stride length of elderly patients with lumbar spinal stenosis: Multi-center study using the Two-Step test

BackgroundShort stride length is one of clinical symptoms associated with lumbar spinal stenosis (LSS). Short stride is a risk factor for falls; therefore, identification of factors associated with short stride is critical for fall prevention in LSS patients. Although the Two-Step test can conveniently assess maximal stride length, it has not become widely used; therefore, its data are limited. We identified the potential factors associated with short stride of elderly LSS patients using Two-Step test.MethodsClinical data of patients aged >65 years who planned to undergo surgery for LSS were prospectively collected at multiple institutions. Patients were assessed with the Two-Step test and Timed Up-and-Go Test prior to surgery; 357 consecutive patients were enrolled. We determined the cut-off value of the Two-Step test score for short stride, referring to the Timed Up-and-Go Test score of 13.5 s, used to indicate high risk of falls in elderly individuals. Logistic regression model was constructed to identify factors associated with short stride.ResultsThe Two-Step test score showed moderate-to-strong inverse correlation with that of Timed Up-and-Go Test (r = ?0.65, p < 0.001). Using the tentative Two-Step test cut-off value (0.93) for short stride, multivariable analysis showed that age ≥80 years (OR = 2.3, 95% CI:1.1–4.8), a score of <60 for lumbar function in Japanese Orthopedic Association Back Pain Evaluation Questionnaire (OR = 2.7, 95% CI:1.5–4.7), motor deficit (OR = 2.7, 95% CI:1.2–6.1), and sagittal vertical axis ≥50 mm (OR = 2.1, 95% CI:1.2–3.5) were factors significantly associated with short stride in elderly patients with LSS.ConclusionsUsing the Two-Step test, we found that 80 years old and over, lumbar dysfunction, motor deficit of the lower extremities, and forward-bent posture were associated with short stride in LSS patients. Therefore, elderly LSS patients with these conditions may have a higher risk for falls.     

Erratum to: Short-Segment Coil Embolization Using a Double-Balloon Technique in an Experimental Vascular Model

CardioVascular and Interventional Radiology -     

Short-Segment Coil Embolization Using a Double-Balloon Technique in an Experimental Vascular Model

CardioVascular and Interventional Radiology - To evaluate the feasibility of short-segment coil embolization between 2 balloons for tight packing in an experimental vascular model. Three coil...