Improved Reliability of Electromyography-Based Neuromuscular Monitoring During Laparoscopic Surgery Achieved by the Modified Attachment Method for Nihon-Kohden NM-345Y™ Stimulating Electrodes: A Case Report

Neuromuscular monitoring is crucial during the administration of neuromuscular blocking agents owing to individual variations in their effects. In electromyography (EMG)-based neuromuscular monitoring using the EMG electrodes (NM-345Y™, Nihon-Kohden Corporation, Tokyo, Japan) following the manufacturer-recommended attachment method, the accuracy of neuromuscular monitoring may be reduced when forearm limb position is changed. We previously devised a novel attachment method for NM-345Y™ stimulating electrodes in adult volunteers to maintain stable monitoring accuracy despite changes in forearm position. Its effectiveness in clinical practice was evaluated by conducting a descriptive study on a 52-year-old woman undergoing laparoscopic uterine surgery. NM-345Y™ electrodes were attached to each forearm following the manufacturer's recommendations (Pattern N) and our novel method (Pattern C). In Pattern C, NM-345Y™ was attached without ultrasound guidance so that the ulnar nerve crossed the line connecting the centers of the anode and cathode of the stimulating electrode. Pattern C exhibited consistent EMG-based monitoring accuracy even with changes in forearm position despite a smaller stimulus current value at calibration. Additionally, Pattern C displayed reliable recovery of the train-of-four (TOF) response after sugammadex administration in the original forearm position, with no observed adverse events. In contrast, Pattern N showed unstable monitoring accuracy after forearm position changes, highlighting the danger of imprecise EMG-based neuromuscular monitoring during the administration of neuromuscular blocking agents. The study's strength lies in identifying Pattern C, where the ulnar nerve crosses the line connecting the anode and cathode, significantly enhancing monitoring accuracy. This novel attachment method holds promise to improve EMG-based neuromuscular monitoring precision in surgery involving forearm limb position changes, although further research is required to assess its utility comprehensively.

Effects of the attachment method of the stimulating electrodes Nihon-Kohden NM-345Y™ and changes in forearm position on stimulus current values during calibration in electromyography-based neuromuscular monitoring: a single-center experimental study

PURPOSE

The traditionally recommended method for attaching electromyography (EMG) electrodes (NM-345Y™) during EMG-based neuromuscular monitoring developed by Nihon-Kohden may decrease the monitoring accuracy when forearm limb position changes. This study investigated methods for attaching stimulating electrodes that maintained stable EMG-based neuromuscular monitoring accuracy, regardless of forearm limb position changes.

METHODS

This single-center experimental study recruited 28 healthy adults from October 2022 to December 2022. The NM-345Y™ was attached to the forearm using three patterns: Pattern N, electrodes attached according to the attachment pattern recommended by Nihon-Kohden; Pattern U, electrodes attached along the ulnar nerve identified using an ultrasound device; Pattern C, electrodes attached where the ulnar nerve crosses the line connecting the centers of the anode and cathode of the stimulating electrodes. The stimulus current values during calibration were measured at three forearm positions for each attachment pattern: supination 90 degrees; pronation 0 degrees; pronation 90 degrees. The differences in stimulus current values caused by forearm position changes were calculated as the difference between values at supination 90 degrees and pronation 0 degrees and between values at supination 90 degrees and pronation 90 degrees.

RESULTS

Pattern C showed significantly smaller differences than Pattern N between the stimulus current values at supination 90 degrees and pronation 0 degrees (p = 0.018) and between the stimulus current values at supination 90 degrees and pronation 90 degrees (p = 0.008).

CONCLUSION

Crossing the ulnar nerve with the line connecting the anode and cathode of the stimulating electrodes may stabilize EMG-based neuromuscular monitoring accuracy.

Analgesic effects of the novel α₂δ ligand mirogabalin in a rat model of spinal cord injury

Mirogabalin, which is a novel ligand for the α₂δ subunit of voltage-gated calcium channels, is under development for the treatment of pain associated with diabetic peripheral neuropathy and postherpetic neuralgia. Mirogabalin possesses unique binding characteristics to α₂δ subunits and potent and long-lasting analgesic effects in peripheral neuropathic pain models. In the present study, we investigated the analgesic effects of mirogabalin in a rat model of spinal cord injury as an experimental animal model for central neuropathic pain. The spinal cord injury model was established by acute compression of the spinal cord at the T6/7 level with a microvascular clip in male rats. Twenty-eight days after spinal cord injury, the animals received the test compound orally, and the paw withdrawal threshold to mechanical stimulation was determined using the von Frey test at 0 (before administration), 2, 4, 6, 8, and 24 h after administration. The area under the curve of the paw withdrawal threshold (paw withdrawal threshold AUC) was also calculated. In rats subjected to spinal cord injury, mechanical allodynia was demonstrated by a decreased paw withdrawal threshold. A single oral administration of mirogabalin (2.5, 5, or 10 mg/kg) significantly increased the paw withdrawal threshold. The effects of mirogabalin were still significant 6 or 8 h after administration. The paw withdrawal threshold AUC was significantly higher in the treated animals than in the control group. In conclusion, mirogabalin showed potent and long-lasting analgesic effects in a rat model of spinal cord injury and may therefore provide effective pain relief for patients with central neuropathic pain.

Factors associated with a positive willingness to practise oral health care in the future amongst oral healthcare and nursing students

OBJECTIVES

The purpose of this study was to identify the weak points in the knowledge and attitudes of first-year oral health care and nursing students towards oral health care and to identify the factors associated with their positive willingness to practise oral health care after becoming a health professional in order to develop oral healthcare curricula.

MATERIALS AND METHODS

The subjects were 88 first-year dental students (DSs), 64 dental hygiene students (DHSs) and 119 nursing students (NSs) enrolled in schools in Japan, as of April 2017. A questionnaire was distributed to subjects in each school to assess their knowledge and attitudes towards oral health care.

RESULTS

Less than half knew that oral health care was also provided in cancer hospitals, hospices, acute care hospitals, maternity wards and psychiatric wards. Only 46.2% knew that oral health care was effective in the prevention of aspiration pneumonia. The level of knowledge and attitudes in NSs regarding oral health care were likely to be lowest amongst the student groups. Only NSs' high interest towards oral health care was associated with their positive willingness to practise oral health care in the future although oral health students' high perceptions and interest regarding oral health care were associated with the willingness.

CONCLUSION

This study showed oral healthcare and nursing students' weak points regarding their attitudes and knowledge of oral health care at early stages. Oral health academic staff and professionals should develop effective oral healthcare curricula for oral healthcare students and help nursing staff develop a collaborative nursing oral healthcare curriculum to motivate nursing students.

Postcomparison of [(18) F]-fluorodeoxyglucose uptake in the brain after short-term bright light exposure and no intervention

OBJECTIVE

Bright light therapy is widely used as the treatment of choice for seasonal affective disorder. Nonetheless, our understanding of the mechanisms of bright light is limited and it is important to investigate the mechanisms. The purpose of this study is to examine the hypothesis that bright light exposure may increase [(18) F]-fluorodeoxyglucose (FDG) uptake in olfactory bulb and/or hippocampus which may be associated neurogenesis in the human brain.

METHOD

A randomized controlled trial comparing 5-day bright light exposure + environmental light (bright light exposure group) with environmental light alone (no intervention group) was performed for 55 participants in a university hospital. The uptake of [(18) F]FDG in olfactory bulb and hippocampus using FDG positron emission tomography was compared between two groups.

RESULTS

There was a significant increase of uptake in both right and left olfactory bulb for bright light exposure group vs. no intervention group. After adjustment of log-transformed illuminance, there remained a significant increase of uptake in the right olfactory bulb.

CONCLUSION

The present findings suggest a possibility that 5-day bright light exposure may increase [(18) F]FDG in the right olfactory bulb of the human brain, suggesting a possibility of neurogenesis. Further studies are warranted to directly confirm this possibility.

Management of sleep-time masticatory muscle activity using stabilisation splints affects psychological stress

To treat sleep bruxism (SB), symptomatic therapy using stabilisation splints (SS) is frequently used. However, their effects on psychological stress and sleep quality have not yet been examined fully. The objective of this study was to clarify the effects of SS use on psychological stress and sleep quality. The subjects (11 men, 12 women) were healthy volunteers. A crossover design was used. Sleep measurements were performed for three consecutive days or longer without (baseline) or with an SS or palatal splint (PS), and data for the final day were evaluated. We measured masseter muscle activity during sleep using portable electromyography to evaluate SB. Furthermore, to compare psychological stress before and after sleep, assessments were made based on STAI-JYZ and the measurement of salivary chromogranin A. To compare each parameter among the three groups (baseline, SS and PS), Friedman's and Dunn's tests were used. From the results of the baseline measurements, eight subjects were identified as high group and 15 as low group. Among the high group, a marked decrease in the number of bruxism events per hour and an increase in the difference in the total STAI Y-1 scores were observed in the SS group compared with those at baseline (P < 0·05). No significant difference was observed in sleep stages. SS use may be effective in reducing the number of SB events, while it may increase psychological stress levels, and SS use did not apparently influence sleep stages.

Degradation of PEP-19, a calmodulin-binding protein, by calpain is implicated in neuronal cell death induced by intracellular Ca2+ overload

Excessive elevation of intracellular Ca2+ levels and, subsequently, hyperactivation of Ca2+/calmodulin-dependent processes might play an important role in the pathologic events following cerebral ischemia. PEP-19 is a neuronally expressed polypeptide that acts as an endogenous negative regulator of calmodulin by inhibiting the association of calmodulin with enzymes and other proteins. The aims of the present study were to investigate the effect of PEP-19 overexpression on cell death triggered by Ca2+ overload and how the polypeptide levels are affected by glutamate-induced excitotoxicity and cerebral ischemia. Expression of PEP-19 in HEK293T cells suppressed calmodulin-dependent signaling and protected against cell death elicited by Ca2+ ionophore. Likewise, primary cortical neurons overexpressing PEP-19 became resistant to glutamate-induced cell death. In immunoprecipitation assay, wild type PEP-19 associated with calmodulin, whereas mutated PEP-19, which contains mutations within the calmodulin binding site of PEP-19, failed to associate with calmodulin. We found that the mutation abrogates both the ability to suppress calmodulin-dependent signaling and to protect cells from death. Additionally, the endogenous PEP-19 levels in neurons were significantly reduced following glutamate exposure, this reduction precedes neuronal cell death and can be blocked by treatment with calpain inhibitors. These data suggest that PEP-19 is a substrate for calpain, and that the decreased PEP-19 levels result from its degradation by calpain. A similar reduction of PEP-19 also occurred in the hippocampus of gerbils subjected to transient global ischemia. In contrast to the reduction in PEP-19, no changes in calmodulin occurred following excitotoxicity, suggesting the loss of negative regulation of calmodulin by PEP-19. Taken together, these results provide evidence that PEP-19 overexpression enhances resistance to Ca2+-mediated cytotoxicity, which might be mediated through calmodulin inhibition, and also raises the possibility that PEP-19 degradation by calpain might produce an aberrant activation of calmodulin functions, which in turn causes neuronal cell death.

Comparative study of attitudes to eating between male and female students in the People's Republic of China

OBJECTIVE

This study was conducted to compare eating attitudes and lifestyles of male and female college students in China (Beijing).

SUBJECTS AND METHODS

The subjects of this study consisted of 217 male and 177 female college students. They were asked to fill out the Eating Attitudes Test-26 (EAT-26) and a lifestyle questionnaire.

RESULTS

The percentages of those above the cutoff point on the EAT-26 for abnormal eating attitudes were 4.7% of male and 6.2% of female students. Body perception of being fat (distorted body image) was the factor most associated with abnormal eating attitudes.

DISCUSSION

Weight related concern was prevalent amongst the Chinese students. This suggests that the culture of the beauty of thinness is common among young students in Beijing, particularly female students.

Factors associated with abnormal eating attitudes among female college students in Japan

OBJECTIVES

To determine the prevalence rates of abnormal eating attitudes and associated risk factors among female Japanese college students.

SUBJECTS AND METHODS

The study population was 7812 female college students in Tokyo. They were asked to fill out the Japanese version of EAT-26 and lifestyle questionnaires.

RESULTS

5.1% of the subjects had a total EAT-26 score above the cutoff point (>20). Multiple regression analysis found the most important factors associated with abnormal eating attitudes were distorted body image, fewer sleeping hours, irregular meal habits, cigarette smoking and more exercise.

DISCUSSION

The prevalence of abnormal eating attitudes among female college students in this study was lower than that of Japanese female high school students and lower than that reported for college students of both western and non-western countries. Our results suggest that body image dissatisfaction may be the most important factor associated with abnormal eating behavior.

Upregulation of T-cell-stimulating activity of mycobacteria-infected macrophages

Macrophages are one of the most abundant host cells to come in contact with mycobacteria. However, the infected macrophages less efficiently stimulate autologous T cells in vitro. We investigated the effect of the induction of phenotypic change of macrophages on the host cell activities by using Mycobacterium leprae as a pathogen. The treatment of macrophages with interferon-gamma (IFN-gamma), GM-CSF and interleukin-4 deprived macrophages of CD14 antigen expression but instead provided them with CD1a, CD83 and enhanced CD86 antigen expression. These phenotypic features resembled those of monocyte-derived dendritic cells (DC). These macrophage-derived DC-like cells (MACDC) stimulated autologous CD4+ and CD8+ T cells when infected with M. leprae. Further enhancement of the antigen-presenting function and CD1a expression of macrophages was observed when treated with IFN-gamma. The M. leprae-infected and -treated macrophages expressed bacterial cell membrane-derived antigens on the surface and were efficiently cytolysed by the cell membrane antigen-specific CD8+ cytotoxic T lymphocytes (CTL). These results suggest that the induction of phenotypic changes in macrophages can lead to the upregulation of host defence activity against M. leprae.

Acetazolamide vasoreactivity in persistent vegetative state and vascular dementia evaluated by transcranial harmonic perfusion imaging and Doppler sonography

To clarify the pathophysiological differences of the cerebrovascular reserve capacity in relation to cerebral cognitive impairments between persistent vegetative state (PVS) and vascular dementia (VD), we evaluated acetazolamide (ACZ) vasoreactivity testing by transcranial harmonic perfusion imaging (HPI) and Doppler sonography (TCD).

METHODS

The subjects were 11 adult patients with severe cognitive impairments (4 PVS, 7 VD). TCD mean velocity (Vm) in the middle and posterior cerebral artery (MCA, PCA) and peak intensity (PI), area under curve (AUC), and mean transit time (MTT) analyzed by HPI time-intensity curves in the bilateral temporal lobe (TL), basal ganglia (BG), and thalamus (Th) were evaluated before and after ACZ administration. Resting values and relative changes (%delta) of TCD and HPI parameters were compared between PVS and VD.

RESULTS

a) Resting values: There were no significant differences between the two groups. b) Vasoreactivity: 1) PVS: %delta Vm decreased in the left PCA and MCA. %delta PI/AUC/MTT decreased in the left TL and bilateral BG. 2) VD: %delta PI/AUC decreased in the right TL. %delta MTT tended to decrease in the right side.

CONCLUSION

ACZ vasoreactivity tests by transcranial HPI and TCD allowed bedside, non-invasive, quantitative evaluation of the pathophysiology of cognitive function impairment and treatments, in relation to cerebrovascular reserve capacity in PVS and VD.

Acetazolamide vasoreactivity evaluated by transcranial harmonic perfusion imaging: relationship with transcranial Doppler sonography and dynamic CT

To establish the reliability and clinical significance of transcranial ultrasonic harmonic perfusion imaging (HPI), we evaluated HPI's relationships with transcranial Doppler (TCD) and with dynamic CT (DCT), during acetazolamide (ACZ) vasoreactivity tests.

METHODS

The subjects were 12 neurological patients. Time-averaged maximum velocity (TAVMX) in the middle (MCA) and posterior cerebral arteries was measured by TCD. Time-intensity (-density) curves of HPI (DCT) after bolus intravenous contrast injections were created in 3 regions of interest (ROI) on the axial plane involving the temporal lobe, basal ganglia, and thalamus on both sides. Assessments of vasoreactivity were based on comparisons conducted before and after ACZ administration in terms of: a) relative changes (%delta) of the TCD TAVMX, b) HPI contrast area enlargement, c) %delta of calculated cerebral blood volume and flow of the HPI and DCT.

RESULTS

1) TCD vasoreactivity decrease in the left MCA tended to correlate with lower frequency of HPI contrast area enlargement on the left side. 2) HPI and DCT vasoreactivity tended to be disturbed in the same side ROIs.

CONCLUSIONS

Transcranial HPI achieves repeatable non-invasive bedside evaluation of cerebrovascular reserve capacity through qualitative and quantitative measurements of brain tissue perfusion, and will have clinical value in pathophysiological follow-up and therapeutic effectiveness determination of neurointensive care patients.

Acetazolamide vasoreactivity in vascular dementia and persistent vegetative state evaluated by transcranial harmonic perfusion imaging and Doppler sonography

To clarify the pathophysiological differences of the cerebrovascular reserve capacity in relation to cerebral cognitive impairments between vascular dementia (VaD) and persistent vegetative state (PVS), we evaluated acetazolamide (ACZ) vasoreactivity testing by transcranial harmonic perfusion imaging (HPI) and Doppler sonography (TCD). Sixteen patients (age: 29-85 years; mean: 62) were divided into three groups: 7 VaD, 4 PVS, and 5 nondementia patients. Mean velocity (Vm) in the middle and posterior cerebral artery (MCA, PCA) was measured, and time-intensity curves of the HPI were evaluated at three regions of interest-the bilateral temporal lobe (TL), basal ganglia (BG), and thalamus (Th). TCD and HPI were evaluated before (resting state) and after ACZ administration, and vasoreactivity was compared among the three groups in terms of resting values and relative changes (%Delta) of Vm, peak intensity (PI), area under curve (AUC), and mean transit time (MTT). Results of the resting state: Decreased Vm, PI, and AUC of the VaD and PVS groups were more obvious in the right side. Results of vasoreactivity: In the PVS group, %DeltaVm decreased in the left PCA and MCA; %DeltaPI and %DeltaAUC decreased in the left TL and bilateral BG. In the VaD group, %DeltaPI and %DeltaAUC decreased in the right TL; %DeltaMTT tended to increase in the left side. ACZ vasoreactivity tests by transcranial HPI and TCD allowed bedside, noninvasive quantitative evaluation of the pathophysiology of cognitive function impairment in relation to cerebrovascular reserve capacity in VaD and PVS.

Reduced Fhit expression is associated with mismatch repair deficiency in human advanced colorectal carcinoma

The Fragile Histidine Triad gene, encompassing the FRA3B fragile site at chromosome 3p14.2, is a candidate tumour suppressor gene involved in multiple tumour types including colorectal carcinomas. Recently, it has been reported that the Fragile Histidine Triad gene may be a target of damage in a fraction of mismatch deficient tumours. To explore this hypothesis, we analysed both Fragile histidine triad and mismatch repair protein (Msh2 and Mlh1) expression using immumohistochemical methods in 52 advanced colorectal carcinomas (19 well-, 17 moderately-, and 16 poorly-differentiated). In addition, we examined whether the Fragile histidine triad and mismatch repair protein expression correlated with p53 expression and clinicopathological findings. Significant loss or reduction of Fragile histidine triad expression was noted in 18 of the 52 (34.6%) advanced colorectal carcinomas: 2 (10.5%) well-differentiated, 3 (17.6%) moderately-differentiated, 13 (81.3%) poorly-differentiated carcinomas, the frequency being significantly higher in the latter than that in the former two (P<0.0001). Loss of mismatch repair protein (mainly, Mlh1) expression was detected in 21 of the 52 (40.4%) colorectal carcinomas. Moreover, reduced Fragile histidine triad expression was significantly associated with absence of mismatch repair protein expression in the advanced colorectal carcinomas (P<0.0001). However, the Fragile histidine triad and mismatch repair protein expression was not significantly associated with p53 expression. These results suggested that reduced Fragile histidine triad expression might be correlated with mismatch repair expression, but not with p53 expression.

Alteration of endothelin-1 concentration in STZ-induced diabetic rat nephropathy. Effects of a PGI(2) derivative

BACKGROUND

Recently, an endothelin (ET-1) with a potent vasoconstrictive activity and stimulative activity of vascular muscular cell growth was discovered and blood ET-1 levels were higher in diabetic patients than in healthy subjects, suggesting that high ET-1 levels assist development and progression of diabetic microangiography.

METHODS

We examined renal function, and serum and tissue ET-1 levels in streptozotocin (STZ)-induced diabetic rats treated with a prostaglandin (PG) I(2) derivative to investigate the effect of PGI(2) in diabetic vascular disturbance.

RESULTS

Renal weight, urinary albumin, urinary N-acetyl-beta,D-glucosaminidase (NAG) and serum ET-1 levels increased in STZ-induced diabetic rats, and a tendency to increase in renal tissue ET-1 levels was observed. Furthermore, electron-microscopic findings in the kidneys showed mesangial cell proliferation and mesangial matrix expansion which might be caused by diabetic nephropathy. The PGI(2) derivative reduced urinary albumin and NAG levels in STZ-induced rats. It was considered, therefore, that the PGI(2) derivative is effective in diabetic nephropathy. As the PGI(2) derivative also reduced renal tissue ET-1 levels, improvement of diabetic nephropathy partially was considered to result from the reduction of renal tissue ET-1 levels.

CONCLUSION

In STZ-induced rats, increased serum ET-1 levels and a tendency to increase in renal tissue ET-1 levels were associated with increases in urinary albumin and NAG levels, and these levels were decreased by a PGI(2) derivative. These findings suggested that increased ET-1 concentrations assist development and progression of diabetic nephropathy, especially diabetic microangiopathy, and the PGI(2) derivative may be effective for inhibition of diabetic microangiopathy mediated by reduction of ET-1 concentrations.

The effects of CD40- and interleukin (IL-4)-activated CD23+ cells on the production of IL-10 by mononuclear cells in Graves' disease: the role of CD8+ cells

The possible roles of CD8+ cells in the abnormal T cell-dependent B-cell activation in Graves' disease were investigated by analysing lymphocyte subsets in peripheral blood mononuclear cells (PBMC) and their production of soluble factors and cytokines such as IL-10 in patients with Graves' disease, Hashimoto's thyroiditis and normal controls. The PBMC were separated into CD8+ and CD8-depleted cells by magnetic separation columns, and cultured for 7 days with or without anti-CD40 monoclonal antibodies and IL-4. The culture supernatant was assayed for sCD23 and IL-10 using EIA, and the remaining cells were analysed by flow cytometry. Stimulation with anti-CD40 antibody together with IL-4 increased sCD23 levels and the number of CD23+ cells. The latter was further augmented by depletion of CD8+ cells. This combination of B cell stimulants increased production of IL-10 by PBMC from patients with Graves' disease. The CD40- and IL-4-activated production of IL-10 was decreased by CD8+ cell depletion. In contrast, constitutive production of IL-10 was increased after CD8+ cell depletion in a group of patients with low basal secretion levels (<35 ng/ml). It was, however, decreased in a group with higher basal production levels, but such a relationship was not found in the normal control group. Thus, T cell-dependent B-cell activation via a CD40 pathway activates CD23+ cells, leading to over-production of IL-10 and a shift of the Th1/Th2 balance to Th2 dominance, while CD8+ cells may suppress this activation to counteract the Th2 deviation in Graves' disease.

Association of CD40 ligand expression on HTLV-I-infected T cells and maturation of dendritic cells

Human T lymphotropic virus type I (HTLV-I) induces HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and adult T-cell leukemia (ATL). The development of HAM/TSP is associated with rapid maturation of dendritic cells (DCs), while ATL is accomplished with their maturation defect. The DC maturation is induced by cell-to-cell contact with CD4+ T cells expressing CD40 ligand (L). We determined the influence of CD40L expressed on various HTLV-I-infected T cells on the DC maturation. Around 60% of CD4+ T cells infected with HTLV-I for 1 week, expressed CD40L molecules involved in DC maturation. DCs matured by the CD40L+ T cells activated autologous CD4+ and CD8+ T cells. HTLV-I-immortalized T-cell lines established from healthy donors consistently expressed CD40L molecules for 3 months, however, some lines lost the expression soon thereafter. Interleukin (IL)-2-independent and transformed lines lacked that expression. Furthermore, T cells obtained from HAM/TSP patients expressed CD40L molecules for at least 3 weeks, whereas T cells from ATL patients did not express that. The CD40L T cells did not induce DC maturation, and required exogenous CD40L molecules for maturation. The CD40L+ T-cell-induced maturation was blocked by anti-CD40L antibody. Therefore, the lack of CD40L expression on HTLV-I-infected T cells may be associated with the development of ATL.

Effect of eicosapentaenoic acid ethyl ester on hypothyroid function

Thyroid hormones affect reactions in almost all pathways of lipid metabolism. It has been reported that plasma free fatty acid (FFA) concentration in hypothyroidism is generally within the normal range. In this study, however, we show that plasma FFA concentration in some hypothyroid patients is higher than the normal range. Symptoms of thyroid dysfunction in these individuals were less severe than those of patients with lower plasma FFA concentrations. From these findings we hypothesized that the change in FFA concentration must correlate with thyroid function. Using an animal model, we then examined the effect of highly purified eicosapentaenoic acid ethyl ester (EPA-E), a n-3 polyunsaturated fatty acid derived from fish oil, on thyroid function in 1-methyl-2-imidazolethiol (MMI)-induced hypothyroid rats. Oral administration of EPA-E inhibited reduction of thyroid hormone levels and the change of thyroid follicles in MMI-induced hypothyroid rats. These findings suggest that FFA may affect thyroid functions and EPA-E may prevent MMI-induced hypothyroidism.

Comparative study between daily and 5-days-a-week administration of oral 5-fluorouracil chemotherapy in mice: determining the superior regimen

BACKGROUND

Oral administration of derivatives of 5-fluorouracil (5-FU) is currently used to treat colorectal cancer in the United States. Oral chemotherapy possesses certain advantages: it is simple, easy to administer, and has few side effects. We compared conventional daily oral administration of 5-FU (daily schedule) with administration on 5 consecutive days followed by 2 drug-free days (5-days-a-week schedule) in a mouse tumor model.

METHODS

The maximal tolerated dose (MTD) in the 5-days-a-week schedule and in the daily schedule were determined in 6-week-old non-tumor-bearing CDF1 male mice. In antitumor experiments, CDF1 mice were inoculated subcutaneously with Colon26 cells (1x10(6) per mouse). Antitumor efficacy was evaluated in terms of the ratio of tumor size in treated to control mice (T/C ratio).

RESULTS

The MTD of 5-FU in the 5-days-a-week schedule was 42 mg/kg, and in the daily schedule was 29 mg/kg. In the 5-days-a-week schedule dose escalation nearly 1.4 times that in the daily schedule was possible, although the total dose over 7 days was similar between the two schedules (203 mg/kg and 210 mg/kg, respectively). When the doses of 5-FU were compared under the condition of no body weight loss, the 5-days-a-week schedule produced a comparative dose escalation of 2.1 times per day (from 20 to 42 mg/kg), and 1.5 times per total weekly amount (from 140 to 210 mg/kg) compared to the daily schedule. With regard to the antitumor effect as indicated by the T/C ratio, the 5-days-a-week schedule produced over 70% tumor suppression, whereas the daily schedule produced only 50% suppression at the MTD. Therapeutic efficacy was calculated in terms of the ratio of body weight change to antitumor effect (T/C ratio), and revealed that the MTD of 42 mg/kg 5-FU in the 5-days-a-week schedule produced a therapeutic efficacy almost three times that of the MTD of 29 mg/kg 5-FU in the daily schedule (P<0.001).

CONCLUSIONS

Using oral administration of 5-FU, we confirmed that the 5-days-a-week schedule allowed dose intensity escalation and was superior to the daily schedule in both enhancement of antitumor effect and protection against adverse effects.

The therapeutic effect of lipo PGE1 on diabetic neuropathy-changes in endothelin and various angiopathic factors

A high blood concentration of endothelin (ET)-1 may participate in the onset and progress of diabetic microangiopathy, resulting in neuropathy. We examined the therapeutic effects of prostaglandin E1 (PGE1), which possesses both a peripheral vasodilating action and inhibition of platelet aggregation, on diabetic microangiopathy. Increases in both skin temperature and peripheral never conduction velocity in diabetic patients were recorded four weeks after Lipo PGE1 administration. A quantitative decrease in urinary albumin concentration was also observed, suggesting its efficacy of action was on diabetic nephropathy. Lipo PGE1 administration reduced the elevated circulating plasma ET-1 levels in the diabetic patients. As an increase in ET-1 concentrations is thought to correlate with the onset and progress of diabetic microangiopathy, the reduction of plasma ET-1 concentration by Lipo PGE1 administration may be one reason for the improvement in diabetic neuropathy and nephropathy.

Dependence of GC-RRTs on the electrical charge at substituents of chlorinated dioxins and related compounds

The correlation between gas chromatograph relative retention times (GC-RRTs) of polychlorinated dioxins and related compounds (PCBs, PCDDs, PCDFs, and PCNs) and descriptors calculated from the electrical charges at substituents, such as the sums of the charges at hydrogen atoms (QH), and chlorine atoms (QCl), and the sum of QH and QCl (Qall), was analyzed for their congeners and isomers. The dependence of GC-RRTs on these descriptors varied dramatically. For the congeners, there was an approximately linear relationship between GC-RRTs and all the descriptors. For the isomers, although there was little significant relationships, by classifying GC-RRTs based on Nad-Cl or Nad-H defined from the number of adjacent chlorine and hydrogen substituents, a linear relationship between GC-RRTs and QH was found for CBs, CDDs, and CDFs, and GC-RRTs for CNs could be classified. From an analysis of the electrical charges at hydrogen substitutents bonded to adjacent and non-adjacent positions, the average-charge of such substituents bonded to adjacent positions decreased with an increase in Nad-H, and this tendency was similar to that for bonding to ortho-, meta-, para-, alpha-, and beta-positions.

A comparative study of characteristics of current-type and conventional-type cationic bactericides

We have synthesized new polycationic bactericides, polyloxyethylene(dimethyliminio)trimethylene(dimethyliminio)ethylene dichloridel (OXD) and poly(hexamethyleneguanidine phosphate) (HEP), in order to develop more active but less skin-irritative bactericides. The effects of these bactericides on Pseudomonas aeruginosa, Escherichia coli, Serratia marcescens, Klebsiella pneumoniae, methicillin resistant Staphylococcus aureus (MRSA) and the degree of their irritations on skin were compared with those of a widely used low molecular-weight cationic bactericide, benzalkonium chloride (BAC), and a polycationic bactericide, poly[2-hydroxyethylene(dimethyliminio)methylene chloride] (2HYC). The minimum bactericidal concentration (MBC) of OXD for 10 min contact incubation was 16 microg/ml against P. aeruginosa, E. coli, S. marcescens and K. pneumoniae, and >1000 microg/ml against MRSA. The MBC of HEP for 10 min contact incubation was 16 microg/ml against P. aeruginosa, 32 microg/ml against E. coli and K. pneumoniae, and 64 microg/ml against S. marcescens and MRSA. Itch, edema, erythema, heat, injury, desquamation and keratinization caused by skin irritation were examined in 21 subjects by patch tests. Only one subject treated with OXD experienced edema, and one subject with HEP experienced keratinization. However, BAC caused itch in 3 subjects, edema in 1, erythema in 10 and desquamation in 2, indicating that the incidence of skin irritation of BAC was higher than that of OXD or HEP. OXD and HEP had sterilization ability similar to BAC, however, they were less skin-irritative than BAC. This indicates that OXD and HEP can be used as safe bactericides.

Dependence of GC-RRTs on the solvent-accessible surface area of dioxins and related compounds

The correlation between gas chromatograph relative retention times (GC-RRTs) of dioxins and related compounds, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated naphthalenes (PCNs), and their solvent-accessible surface area (SAS) was analyzed for congeners and isomers. GC-RRTs were linearly dependent on SAS for congeners while there was little dependence for isomers. However, by using classification parameters, Nad-Cl, Nad-H, N1,9Cl, and NalphaCl, based on the substitution positions and patterns of chlorine and/or hydrogen atoms bound to the molecular skeleton, a linear relationship was found among isomers. Furthermore, the GC-RRTs of CDD, CDF, and CN isomers, which are planar, decreased despite increasing SAS, and this tendency was enhanced with the above classification. The retention behavior was explained in terms of the effective enhancement of molecular hydrophobicity caused by an increase in the number of adjacent chlorine pairs.

IL-12 and IL-18 synergistically induce the bactericidal activity of murine peritoneal cells against M. leprae

We examined the effect of IL-12 and IL-18 on bactericidal activities of mouse peritoneal cell (PC) against Mycobacterium leprae (M. leprae). We demonstrated that IL-12 and IL-18 synergistically induced the NO-dependent bactericidal activity of PC by stimulating Natural Killer (NK) cells and T-cells through IFN-gamma production. IL-12 and IL-18 induced host cell death through NK-cells and T-cells. Therefore. IL-12 and IL-18 play an important role on direct killing of intracellular M. leprae and on indirect killing of them through inducing host cell death.

[Evaluation of efficiency of a multi-crystal scintillation camera Digirad 2020tc Imager using a solid-state detectors]

Digirad 2020tc Imager is the movable scintillation camera, consisting of combining multi-crystal scintillators (CsI(Tl)) and photo-diodes. Total numbers of element are 4096, which are further divided into 16 x 16 modules. Each module contains 4 x 4 elements. We have examined Digirad 2020tc according to NEMA (National Electrical Manufactures Association), and the following results are obtained; the maximum count rate; 221 kcps, total system uniformity; 1.3% (integral uniformity), 0.9% (differential uniformity), system spatial resolution; 6.97 +/- 0.72 mm (the LEHR collimator to 99mTc source at 10 cm), intrinsic energy resolution; 12.8%, total system sensitivity; 3270.8 cpm/MBq (with LEHR collimator using 99mTc source at 10 cm). Further more, we determined the contrast of an imaging using the pin-hole (100 microns phi) 99mTc source in order to know the signal per noise (S/N) ratio among the pixels (S/N; 93.4 +/- 46.2 (first pixels)). Although the physical dimension of the camera has a smaller field of view, comparing with the standard camera, Digirad 2020tc has the equivalent characteristics as well as that of the standard camera and its field view is enough to measure the adult lung perfusion using a diverging collimator. We will further examine Digirad 2020tc with its movable portability and expect applications in nuclear medicine.

Clinical significance of E-cadherin-catenin complex expression in metastatic foci of colorectal carcinoma

BACKGROUND AND OBJECTIVES

Reduced expressions of cell adhesion molecules (E-cadherin, alpha-catenin, and beta-catenin) has been reported to be associated with tumor metastasis. However, the clinical significance of such adhesion molecules in the metastatic foci remains unclear. In this study, we evaluated the prognostic significance of E-cadherin, alpha-catenin, and beta-catenin expressions in the metastatic foci of patients with colorectal carcinoma.

METHODS

The expressions of E-cadherin, alpha-catenin, and beta-catenin were detected immunohistochemically in 105 primary tumors, in 30 metastatic lymph nodes, and 13 metastatic liver tumors from consecutive patients with colorectal carcinoma.

RESULTS

Reduced normal expression of E-cadherin, alpha-catenin, and beta-catenin in comparison with normal epithelium was detected in 78 primary tumors, respectively. Patients who had tumors with reduced expression of adhesion molecules showed unfavorable prognosis and the reduced expression of adhesion molecules was detected as one of the independent prognostic factors for patients with colorectal carcinoma. In 30 patients with lymph node metastasis, the increased expression of adhesion molecules in metastatic lymph nodes compared with primary tumors was detected in 13 patients. The prognosis of these 13 patients was poorer than that of remaining 17 patients (P = 0.0296). Also, in 13 patients with liver metastasis, even no significant difference was observed, the mean survival time of 6 patients who had metastatic liver tumors with increased expression of adhesion molecules (10 months) was shorter than that of the remaining 7 patients (16 months; P = 0.1718).

CONCLUSIONS

These results suggest that increased expression of the cadherin-catenin cell-cell adhesion system in metastatic foci may play an important role in progression of metastatic colorectal carcinomas.

Substrate-bound fibronectin enhances scavenger receptor activity of macrophages by calcium signaling

We have previously found that ability of mouse macrophages to bind and take up oxidized low-density lipoprotein (oxLDL) through scavenger receptors is significantly enhanced when the cells are plated on fibronectin (FN)-coated culture substrates. Here, the mechanisms of the enhancement of the scavenger receptor activity by the substrate-bound FN was investigated using thioglycollate-induced mouse peritoneal macrophages. A Ca(2+) channel blocker diltiazem and a calmodulin inhibitor W-7 reduced the scavenger receptor activity of the macrophages plated on FN-coated substrate to the level of the cells plated on uncoated substrate, as assessed by oxLDL binding, while the scavenger receptor activity of the macrophages on uncoated substrate was little affected. Similarly, FN-induced enhancement of the scavenger receptor activity assessed by oxLDL uptake was selectively inhibited by Ca(2+) channel blockers (diltiazem, nifedipine, verapamil) and calmodulin inhibitors (W-7, trifluoperazine). Intracellular free Ca(2+) level of the macrophages was increased, depending on extracellular Ca(2+), when plated on FN-coated substrate. This increase in the Ca(2+) level was inhibited by diltiazem and RGD-containing peptides present in cell adhesive region of FN. Like the substrate-bound FN, Ca(2+) ionophore A23187 enhanced the scavenger receptor activity of binding and taking up of oxLDL. These results indicate that substrate-bound FN enhances scavenger receptor activity of macrophages by increasing channel-dependent Ca(2+) influx. A microtubule disruptor, colchicine, and an actin filament disruptor, cytochalasin B, inhibited the FN-induced enhancement of the scavenger receptor activity, suggesting that these cytoskeletal structures are required for transmission of the adhesion signal of FN. The number of the scavenger receptors was found to increase by 1.4-fold upon adhesion signal of FN. We suggest that substrate-bound FN increases the number of the macrophage scavenger receptors as a result of induction of Ca(2+) influx and causes increased accumulation of oxLDL within the cells, rendering the cells more susceptible to conversion into foam cells.

Polymorphisms of the insulin gene among Japanese subjects

We have sequenced the insulin gene in 72 unrelated Japanese subjects (52 with type 2 diabetes mellitus and 20 with normal glucose tolerance). We identified 6 mutations and all were found at a low frequency (1% to 4%). Three mutations were new. These included a C-to-G substitution in the promoter region, a G-to-A substitution in codon-2 resulting in an Ala-to-Thr replacement in amino acid -2 of the signal peptide, and a G-to-A substitution in intron 2. We have no evidence that any of the mutations that we found are the cause of diabetes. Thus, mutations in the insulin gene do not appear to be an important genetic factor contributing to the development of diabetes in this population.

Pharmacological Properties of Fidarestat, a Potent Aldose Reductase Inhibitor, Clarified by Using Sorbitol in Human and Rat Erythrocytes

We examined the effect of fidarestat on the increase in sorbitol content in erythrocytes from healthy volunteers in vitro. Fidarestat inhibited the increase with an IC50 value of 18 nmol/l. A subsequent experiment showed that fidarestat had a similar inhibitory effect on the increase in sorbitol content in erythrocytes from diabetic patients. On the other hand, epalrestat, the only aldose reductase inhibitor used clinically, inhibited increase in sorbitol content at a concentration over 500-fold higher than fidarestat. Although the IC50 value of fidarestat was not affected by fasting plasma glucose, HbA1C, age, aldose reductase content or gender, there was a significant positive relationship between the IC50 value of epalrestat and fasting plasma glucose. In addition, in fidarestat (0.25-2 mg/kg)-treated diabetic rats, the inhibitory rate for erythrocyte sorbitol accumulation was well correlated with that for nerve sorbitol accumulation, which indicates that erythrocyte sorbitol is available for assessing the state of sorbitol pathway flux in target tissue after fidarestat administration. These results suggest that fidarestat potently inhibits the increase in sorbitol pathway flux in diabetic patients independent of various factors and that erythrocyte sorbitol is useful for its estimation.

Dihydropyrimidine dehydrogenase activity of cancerous and non-cancerous tissues in liver and large intestine

5-fluorouracil (5-FU) is a widely used chemotherapeutic agent for various carcinomas. However, the therapeutic effect of 5-FU differs among patients. The differences in the effectiveness of 5-FU are thought to be based on the different enzymatic activity which inactivates 5-FU of the host tissue. 5-FU is catabolized to 2-fluoro-beta-alanine by dihydropyrimidine dehydrogenase (DPD) in liver and tumors. In this study, we investigated the clinical significance of detecting DPD activity in patients with hepatocellular and colorectal carcinomas. DPD activity in 63 hepatocellular carcinomas (HCCs), 3 cholangiocellular carcinomas (CCCs), 63 non-cancerous liver tissues adjacent to HCCs (N-HCCs), 6 normal livers (NLs), 189 colorectal carcinomas (CRCs), and 189 non-cancerous colorectal mucosas (N-CRCs) was analyzed by enzyme-linked immunosorbent assay (ELISA). The mean DPD activities of these tissues were 209 +/- 187 Unit (U)/mg protein (HCC), 140 +/- 34 (CCC), 105 +/- 50 (N-HCC), 93 +/- 24 (NL), 58 +/- 45 (CRC), and 83 +/- 92 (N-CRC). DPD activity of HCC was higher than that of CRC (p < 0.0001). DPD activity of N-HCC was higher than that of N-CRC (p < 0.0001). DPD activity of HCC was higher than that of N-HCC (p = 0.0014), on the other hand, DPD activity of CRC was lower than that of N-CRC (p < 0.0001). Tumor DPD activity in HCC and CRC did not correlate with tumor differentiation or progression nor with patient survival. In 20 CRC patients with synchronous liver metastasis, who underwent post-operative 5-FU chemotherapy through the hepatic artery, the mean survival time (29 months) of 9 patients with high DPD was not significantly different from that of 11 patients with low DPD (18 months, p = 0.3412). These findings could provide an explanation for the relative 5-FU resistance of HCC compared with CRC. However, the DPD activities of tumors may not reveal tumor differentiation or progression in HCCs or in CRCs. Moreover, the DPD activity of primary CRC may not be a good indicator of the 5-FU chemosensitivity of synchronous liver metastasis.

Studies on the constituents of the leaves of Morus alba L

Two novel prenylflavanes (1, 2) and a glycoside (3) of 1 were isolated along with six known compounds, isoquercitrin (4), astragalin (5), scopolin (6), skimmin (7), roseoside II (8) and benzyl D-glucopyranoside (9), from the leaves of Morus alba. The inhibitory activities of compounds 1, 2 and 3 on the oxidation of human low density lipoprotein (LDL) were investigated.

Impaired IL-15 production associated with susceptibility of murine AIDS to mycobacterial infection

LP-BM5 murine leukemia virus (MuLV) injection causes murine AIDS (MAIDS), a disease characterized by many functional abnormalities of immunocompetent cells. We show that MAIDS mice are susceptible to Mycobacterium bovis Bacille Calmette-Guérin (BCG) infection as assessed by survival rate and bacterial counts. The peritoneal exudate macrophages from MAIDS mice produced a significant level of interleukin (IL)-12 soon after inoculation with BCG, whereas IL-15 and tumor necrosis factor (TNF) production were severely impaired in BCG-infected MAIDS mice. The appearance of natural killer (NK) and CD4+ T helper type 1 (Th1) cells specific for mycobacterial antigen were depressed in MAIDS mice after BCG infection. Thus, it appeared that impaired production of IL-15, besides other inflammatory cytokines, in MAIDS mice may be involved in the poor responses of the NK and Th1 cells, resulting in an increased susceptibility to BCG.

N-acetyl cysteine inhibits cell cycle progression in pancreatic carcinoma cells

The antioxidant N-acetyl cysteine (NAC) is a precursor of intracellular glutathione (GSH) and is also a well known as one of the chemopreventive agents which act through a variety of cellular mechanisms. We examined the effects of NAC on cell cycle progression in the pancreatic carcinoma cell lines, SW1990 and JHP1. Cells were incubated with or without NAC. Cell cycle distribution was analyzed by flow cytometry and immunoblotting. NAC suppressed cell proliferation in a concentration-dependent manner, whereas NAC increased intracellular glutathione content significantly in a dose-dependent manner. The percentage of cells in the G1 phase after treatment with NAC was significantly higher than the percentage seen for control cells. Cyclin D1 expression of carcinoma cells treated with NAC decreased remarkably compared with cells without NAC treatment. Thus, the antiproliferative effect of NAC by prolongation of the G1 phase in human pancreatic carcinoma cells shows its possible utility as an antitumor agent.

[A patient of infantile polymyositis triggered by respiratory syncytium virus infection]

An 11-month-old boy developed acute polymyositis about 1 week after respiratory syncytium virus (RSV) pneumonia. He was admitted to our hospital because of interstitial pneumonia. RSV infection was confirmed by the presence of its antigen in his nasal discharge. Two weeks later, his chest X-ray findings improved and RSV antigen became negative, but severe generalized muscle weakness developed, causing respiratory failure. Muscle biopsy demonstrated inflammatory cellular infiltration with occasional fiber necrosis. Intravenous steroid pulse therapy was remarkably effective resulting in complete recovery of his muscle power. In this patient polymyositis was preceded with RSV infection, suggesting a close relationship between polymyositis and RSV infection. Although many patients of viral myositis have been reported to be associated with coxsackie B, HCV and HTLV-1 viruses, our patient is the first infantile polymyositis secondary to RSV infection.

A novel bisnorditerpenelactone from Mikania hirsutissima

A novel bisnorkaurenic acid-type diterpenelactone, named mikanialactone (1), was isolated along with five known kaurenic acid-type diterpenes (2-6) from the aerial parts of Mikania hirsutissima DC (Compositae). The structure of the new bisnorditerpene was determined by spectroscopic means.