Effect of low-level clenching and subsequent muscle pain on exteroceptive suppression and resting muscle activity in human jaw muscles.

OBJECTIVE: To investigate the effects of muscle fatigue induced by low-level isometric jaw-clenching and subsequent glutamate-evoked muscle pain on the exteroceptive suppression (ES) response and resting electromyographic (EMG) activities in human jaw muscles. METHODS: The resting EMG activity and the ESs were recorded before (baseline), after low-level jaw-clenching (Post1), after subsequent glutamate or isotonic saline injections into the left masseter (Post2), and 60 min after the clenching (Post3) in 23 healthy volunteers. RESULTS: The late ES (ES2) showed more inhibition at Post1 compared with baseline (P<0.05). It was less inhibited after both types of injections (Post2), and increased at Post3 again (P<0.05) with no significant difference between the glutamate and isotonic saline sessions. The resting EMG activity increased at Post1 and Post2 (P<0.05). The glutamate injection further increased the resting EMG activity in the injected muscle (P<0.01). CONCLUSIONS: Muscle fatigue influences inhibitory reflex pathways in jaw-closing muscles and subsequent acute muscle pain potentiates the local increase in the resting EMG activity of the painful muscle. SIGNIFICANCE: Muscle fatigue which can be observed in patients with oral dysfunctions may interact with nociceptive regulation and influence the clinical presentation of jaw symptoms and function.     

Influence of sperm immobilization on onset of Ca(2+) oscillations after ICSI

Sperm immobilization prior to intracytoplasmic sperm injection (ICSI) is thought to be necessary for efficient fertilization. A variety of methods of sperm immobilization (pipetting, squeezing and piezo application) are currently employed in ICSI. The effect of differences in immobilization method on the timing of initial Ca(2+) oscillations of oocytes in ICSI was investigated. Motile spermatozoa were immobilized in eosin Y solution using pipetting, squeezing and piezo application. Complete staining of the sperm head was achieved after 220.7, 42.2 and 5.0 s respectively. Oscillations after ICSI were measured fluorometrically for each method. The onset of Ca(2+) oscillations was observed at 4.8 to 80.4 min after ICSI. Ca(2+) oscillations developed earlier with the piezo method (14.4 +/- 6.4 min) than other methods (pipetting, 43.1 +/- 20.2 min, P < 0.01; squeezing, 18.4 +/- 3.8 min, P = NS). The piezo method produced the earliest staining of the sperm head and may have caused the most damage to the sperm membrane. A more rapid onset of Ca(2+) oscillations was also observed with the piezo method. The method of sperm immobilization may be important for the rapid release of sperm factors that initiate oocyte activation. This study also showed that Ca(2+) oscillations develop earlier in human oocytes treated by ICSI than indicated in previous reports.     

Prognostic predictive values of serum cytochrome c, cytokines, and other laboratory measurements in acute encephalopathy with multiple organ failure.

AIMS: To evaluate the prognostic predictive values of cytochrome c, cytokines, and other laboratory measurements in serum collected during neurological onset in acute encephalopathy with multiple organ failure. METHODS: In addition to general laboratory examinations, the concentrations of cytochrome c (apoptosis marker) and cytokines (inflammatory markers) were measured in serum samples collected at the initial phase in 29 patients with acute encephalopathy. The obtained values were evaluated as predictors for the development of severe encephalopathy. RESULTS: Cytochrome c, tumour necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), soluble TNF-receptor 1 (sTNF-R1), and aspartate aminotransferase (AST) concentrations at the initial phase were high and correlated well with patient outcome. High concentrations of serum cytochrome c (>45 ng/ml), sTNF-R1 (>2000 pg/ml), AST (>58 IU/dl), IL-6 (>60 pg/ml), and TNF-alpha (>15 pg/ml) predicted an unfavourable prognosis (sequelae and death) at 93%, 79%, 82%, 77%, and 60%, respectively. The specificity of those markers was 100%, 89%, 83%, 100%, and 100%, respectively. CONCLUSIONS: Serum cytochrome c is the most sensitive and specific predictor for the development of severe encephalopathy at the initial phase. Results suggest that this marker might be used to guide decisions regarding the start of the initial treatment and further intensive care.     

Evaluation of beam hardening and photon scatter by brass compensator for IMRT

When a brass compensator is set in a treatment beam, beam hardening may take place. This variation of the energy spectrum may affect the accuracy of dose calculation by a treatment planning system and the results of dose measurement of brass compensator intensity modulated radiation therapy (IMRT). In addition, when X-rays pass the compensator, scattered photons are generated within the compensator. Scattered photons may affect the monitor unit (MU) calculation. In this study, to evaluate the variation of dose distribution by the compensator, dose distribution was measured and energy spectrum was simulated using the Monte Carlo method. To investigate the influence of beam hardening for dose measurement using an ionization chamber, the beam quality correction factor was determined. Moreover, to clarify the effect of scattered photons generated within the compensator for the MU calculation, the head scatter factor was measured and energy spectrum analyses were performed. As a result, when X-rays passed the brass compensator, beam hardening occurred and dose distribution was varied. The variation of dose distribution and energy spectrum was larger with decreasing field size. This means that energy spectrum should be reproduced correctly to obtain high accuracy of dose calculation for the compensator IMRT. On the other hand, the influence of beam hardening on k_Q was insignificant. Furthermore, scattered photons were generated within the compensator, and scattered photons affect the head scatter factor. These results show that scattered photons must be taken into account for MU calculation for brass compensator IMRT.     

Decreased plasma adiponectin concentrations in women with low-grade C-reactive protein elevation

OBJECTIVE: Inflammation has been suggested as a risk factor for the development of atherosclerosis, while some components of metabolic syndrome X have been related to inflammatory markers. We hypothesized that adipocyte secreting protein, adiponectin and leptin, for which have been demonstrated an association with metabolic syndrome X and coronary artery disease, may be associated with inflammatory markers in nondiabetic humans. DESIGN AND METHODS: We measured high-sensitivity C-reactive protein (hs-CRP), as an inflammatory marker, and adiponectin and leptin concentrations in 384 nondiabetic Japanese women (mean+/-s.e.m. age 53.6+/-0.8 Years, body mass index (BMI) 23.0+/-0.2 kg/m(2)) undergoing measurement of markers of metabolic syndrome X. RESULTS: The women who had a low-grade hs-CRP elevation (>2.0 mg/l) were significantly older and had higher BMI, body fat mass (BFM), total cholesterol (TC), triglyceride (TG), atherogenic index (AI=(TC-HDLC)/HDLC), where HDLC is high-density lipoproten-cholesterol), fasting blood glucose and leptin concentrations before and after adjustment for BMI or BFM, while lower HDLC and adiponectin concentrations before and after adjustment compared with women with normal CRP levels (<0.5 mg/l). BMI, BFM, TG, AI and leptin before and after adjustment were found to be correlated with hs-CRP levels, while HDLC and adiponectin before and after adjustment were inversely correlated (all P<0.0001). hs-CRP was independently associated with white blood cell count, blood urea nitrogen and AI and inversely with adiponectin/BFM in the stepwise regression analysis model. CONCLUSIONS: These data demonstrate a significant decrease in plasma adiponectin in low-grade chronic inflammation, and suggest that there is an important linkage between inflammation/adipose tIssue/atherosclerosis.     

The efficacy of oral vitamin A supplementation for measles and respiratory syncytial virus (RSV) infection

Recently, the efficacy of oral vitamin A supplementation for measles and respiratory syncytial (RSV) infection has been evaluated in developing countries. However, in developed countries where vitamin A deficiency is little worth consideration, few studies have been conducted on the effect of vitamin A supplementation. The effect of oral vitamin A (100,000 IU) supplementation was evaluated in 105 children with measles (age 5 months to 4 years) and in 96 children with RSV infection (ages a month to 2.5 years) in Fukushima, Japan. Comparisons were made of clinical signs, duration of hospitalization and complications between treated groups and non-treated groups. Treated group (measles n = 47, RSV n = 54) and non-treated groups (measles n = 58, RSV n = 42) had similar baseline characteristics. Patients with measles given a vitamin A supplementation had a shorter duration of cough (7.2 +/- 1.6 vs 9.2 +/- 1.8 days, p < 0.05) and patients with severe RSV infection given a vitamin A supplementation had a shorter duration of retraction (3.6 +/- 1.4 vs 5.3 +/- 0.8 days, p < 0.05) and wheezing (4.4 +/- 1.7 vs 6.3 +/- 1.5 days, p < 0.05). Toxicities, including excess vomiting and bulging fontanel were not observed. Our findings may suggest the efficacy of oral vitamin A supplementation for measles and severe RSV infection, in children who have no malnutrition.     

Elevated serum leptin concentrations in women with hyperuricemia

The serum uric acid level has been said to be an independent predictor of cardiovascular disease death, mainly for women, and to be linked with the metabolic Syndrome X of insulin resistance, obesity, hypertension, and dyslipidemia. Recently, it has been suggested that the elevation of serum leptin, the ob gene product, may have a role in metabolic Syndrome X. Therefore, we studied the relationship of uric acid to leptin in 822 Japanese women in a cross-sectional manner. To estimate the effect of uric acid on the variables of metabolic Syndrome X, we calculated mean values of various components of the syndrome according to tertiles of uric acid (UA < 4.0 mg/dl, 4.0 < or = UA < 5.5, 5.5 < or = UA). Age, systolic and diastolic blood pressure (BP), body mass index (BMI), percent body fat mass (BFM), serum total cholesterol, triglyceride, atherogenic index, leptin, fasting immunoreactive insulin and homeostasis model assessment-ratio (HOMA-R: calculated insulin resistance) were significantly different across the uric acid tertiles with higher levels in the highest tertile in comparison to the first (ANOVA, p < 0.001, 0.001, 0.002, 0.001, 0.001, 0.025, 0.001, 0.001, 0.001, 0.001, 0.001, respectively), while high density lipoprotein cholesterol showed lower levels (p < 0.001). Serum leptin concentrations were also elevated in hyperuricemic women after adjusting for BMI or BFM (both p < 0.001), and were weakly correlated with serum uric acid concentrations (r = 0.22, p < 0.0001). BMI, HOMA-R, serum triglyceride, diastolic BP and age-adjusted serum leptin concentrations were calculated for each tertile of serum uric acid. Compared with the lowest tertile of uric acid level, BMI, HOMA-R, serum triglyceride, diastolic BP and age-adjusted leptin concentrations were higher in the highest tertile. In the stepwise regression analysis, serum leptin was the significant independent variable for uric acid values. These results indicate an independent relationship between leptin and uric acid, further supporting the involvement of leptin in metabolic Syndrome X.     

Relationship between shear elastic modulus and passive force of the human rectus femoris at multiple sites: a Thiel soft-embalmed cadaver study

Journal of Medical Ultrasonics - Estimation of muscle passive force from elasticity using shear wave elastography (SWE) has been reported. However, the relationship between the elasticity and...     

Acute decrease in the stiffness of resting muscle belly due to static stretching

The purpose of the study was to examine the acute effect of static stretching exercise on the resting stiffness of gastrocnemius muscle belly. Ten healthy young adults performed standing wall stretching in dorsiflexion for 1 min at a time and repeated five times. Before and after stretching, the shear modulus was measured in medial and lateral heads of the resting gastrocnemius muscle with ultrasound shear‐wave elastography. After the stretching, dorsiflexion range of motion (ROM) of the ankle joint increased (P < 0.01) by 3.9° and returned in 20 min. Immediately after stretching, shear modulus decreased (P < 0.01) by 14%, compared with before stretching across muscle heads. The decrease in shear modulus returned in 20 min after stretching. In the comparison group of 10 additional subjects, the standing intervention without stretching had no influence on these measures. There was a negative correlation between dorsiflexion ROM and shear modulus in either head before and after stretching. The results demonstrate the transient decreases in the stiffness of the resting gastrocnemius muscle belly and indicate that joint flexibility is greater in individuals with lower resting stiffness of the muscle belly.     

Cholestatic Liver Injury After Biliary Reconstruction Impairs Transplanted Islet Viability and Function

Islet autotransplantation following total pancreatectomy differs from allograft transplantation with respect to the requirement of biliary reconstruction. Although it is known that careful consideration should be given to postoperative cholestatic liver injury after biliary reconstruction, its direct effects on transplanted islets have not been completely elucidated. In this study, we developed a murine model of postoperative cholestatic liver injury after biliary reconstruction with islet autotransplantation that involved syngeneic intraportal islet transplantation into chemically induced diabetic mice and common bile duct ligation. We assessed the viability and function of the transplanted islets. The impaired viability of transplanted islets and increased blood glucose levels indicated restoration of the diabetic state after common bile duct ligation in this murine model. Furthermore, impaired islet viability and function occurred earlier in the transplanted islets than in the surrounding liver tissues, which was consistent with the faster and higher expression of oxidative stress markers in the transplanted islets. Transplanted islets may be more vulnerable to oxidative stress caused by cholestatic liver injury than the surrounding liver tissue. Therefore, patients should be intensively managed after total pancreatectomy with islet autotransplantation to preserve viability and function of the transplanted islets.