Measurements of neutrino oscillation parameters from the T2K experiment using 3.6×1021 protons on target

The T2K experiment presents new measurements of neutrino oscillation parameters using 19.7 ( 16.3 ) × 10 20 protons on target (POT) in (anti-)neutrino mode at the far detector (FD). Compared to the previous analysis, an additional 4.7 × 10 20 POT neutrino data was collected at the FD. Significant improvements were made to the analysis methodology, with the near-detector analysis introducing new selections and using more than double the data. Additionally, this is the first T2K oscillation analysis to use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux model, and the neutrino interaction model was improved to include new nuclear effects and calculations. Frequentist and Bayesian analyses are presented, including results on sin 2 θ 13 and the impact of priors on the δ CP measurement. Both analyses prefer the normal mass ordering and upper octant of sin 2 θ 23 with a nearly maximally CP-violating phase. Assuming the normal ordering and using the constraint on sin 2 θ 13 from reactors, sin 2 θ 23 = 0 . 561 - 0.032 + 0.021 using Feldman-Cousins corrected intervals, and Δ m 32 2 = 2 . 494 - 0.058 + 0.041 × 10 - 3 eV 2 using constant Δ χ 2 intervals. The CP-violating phase is constrained to δ CP = - 1 . 97 - 0.70 + 0.97 using Feldman-Cousins corrected intervals, and δ CP = 0 , π is excluded at more than 90% confidence level. A Jarlskog invariant of zero is excluded at more than 2 σ credible level using a flat prior in δ CP , and just below 2 σ using a flat prior in sin δ CP . When the external constraint on sin 2 θ 13 is removed, sin 2 θ 13 = 28 . 0 - 6.5 + 2.8 × 10 - 3 , in agreement with measurements from reactor experiments. These results are consistent with previous T2K analyses.

Changes in cerebrovascular disease-related deaths and their location during the COVID-19 pandemic in Japan

Objective

The COVID-19 pandemic placed an enormous strain on healthcare systems and raised concerns for delays in the management of patients with acute cerebrovascular events. In this study, we investigated cerebrovascular excess deaths in Japan.

Study design

Vital mortality statistics from January 2012 to May 2022 were obtained from the Japanese Ministry of Health, Labour and Welfare.

Methods

Using quasi-Poisson regression models, we estimated the expected weekly number of cerebrovascular deaths in Japan from January 2020 through May 2022 by place of death. Estimates were calculated for deaths in all locations, as well as for deaths in hospitals, in geriatric health service facilities, and at home. The age subgroups of ≥75 and <75 years were also considered. Weeks with a statistically significant excess of cerebrovascular deaths were determined when the weekly number of observed deaths exceeded the upper bound of 97.5% prediction interval.

Results

Excess deaths were noted in June 2021 and became more pronounced from February 2022 onwards. The trend was notable among those aged ≥75 years and for those who died in hospitals. With respect to the location of deaths, the excess was significant in geriatric health services facilities from April 2020 to June 2021, while no evidence of excess hospital deaths was observed during the same period.

Conclusions

Beginning in late 2021, excess cerebrovascular deaths coincided with the spread of the Omicron variant and may be associated with increased healthcare burden. In 2020, COVID-19 altered the geography of cerebrovascular deaths, with fewer people dying in hospitals and more dying in geriatric health service facilities and at home.

Excess deaths from COVID-19 in Japan and 47 prefectures from January through June 2021

Objectives

In Japan, several studies have reported no excess all-cause deaths (the difference between the observed and expected number of deaths) during the coronavirus disease 2019 (COVID-19) pandemic in 2020. This study aimed to estimate the weekly excess deaths in Japan's 47 prefectures for 2021 until June 27.

Study design

Vital statistical data on deaths were obtained from the Ministry of Health, Labour and Welfare of Japan. For this analysis, we used data from January 2012 to June 2021.

Methods

A quasi-Poisson regression was used to estimate the expected weekly number of deaths. Excess deaths were expressed as the range of differences between the observed and expected number of all-cause deaths and the 95% upper bound of the one-sided prediction interval.

Results

Since January 2021, excess deaths were observed for the first time in the week corresponding to April 12–18 and have continued through mid-June, with the highest excess percentage occurring in the week corresponding to May 31–June 6 (excess deaths: 1431–2587; excess percentage: 5.95–10.77%). Similarly, excess deaths were observed in consecutive weeks from April to June 2021 in 18 of 47 prefectures.

Conclusions

For the first time since February 2020, when the first COVID-19 death was reported in Japan, excess deaths possibly related to COVID-19 were observed in April 2021 in Japan, during the fourth wave. This may reflect the deaths of non-infected people owing to the disruption that the pandemic has caused.

A peptide of the N terminus of GRK5 attenuates pressure-overload hypertrophy and heart failure

Aberrant changes in gene expression underlie the pathogenesis and progression of pressure-overload heart failure, leading to maladaptive cardiac hypertrophy, ventricular remodeling, and contractile dysfunction. Signaling through the G protein G_q triggers maladaptation and heart failure, in part through the activation of G protein-coupled receptor kinase 5 (GRK5). Hypertrophic stimuli induce the accumulation of GRK5 in the nuclei of cardiomyocytes, where it regulates pathological gene expression through multiple transcription factors including NFAT. The nuclear targeting of GRK5 is mediated by an amino-terminal (NT) domain that binds to calmodulin (CaM). Here, we sought to prevent GRK5-mediated pathology in pressure-overload maladaptation and heart failure by expressing in cardiomyocytes a peptide encoding the GRK5 NT (GRK5nt) that encompasses the CaM binding domain. In cultured cardiomyocytes, GRK5nt expression abrogated G_q-coupled receptor-mediated hypertrophy, including attenuation of pathological gene expression and the transcriptional activity of NFAT and NF-κB. We confirmed that GRK5nt bound to and blocked Ca²⁺-CaM from associating with endogenous GRK5, thereby preventing GRK5 nuclear accumulation after pressure overload. We generated mice that expressed GRKnt in a cardiac-specific fashion (TgGRK5nt mice), which exhibited reduced cardiac hypertrophy, ventricular dysfunction, pulmonary congestion, and cardiac fibrosis after chronic transverse aortic constriction. Together, our data support a role for GRK5nt as an inhibitor of pathological GRK5 signaling that prevents heart failure.

GRK5 is a regulator of fibroblast activation and cardiac fibrosis

Pathological remodeling of the heart is a hallmark of chronic heart failure (HF) and these structural changes further perpetuate the disease. Cardiac fibroblasts are the critical cell type that is responsible for maintaining the structural integrity of the heart. Stress conditions, such as a myocardial infarction (MI), can activate quiescent fibroblasts into synthetic and contractile myofibroblasts. G protein-coupled receptor kinase 5 (GRK5) is an important mediator of cardiovascular homeostasis through dampening of GPCR signaling, and is expressed in the heart and up-regulated in human HF. Of note, GRK5 has been demonstrated to translocate to the nucleus in cardiomyocytes in a calcium-calmodulin (Ca2+-CAM)-dependent manner, promoting hypertrophic gene transcription through activation of nuclear factor of activated T cells (NFAT). Interestingly, NFAT is also involved in fibroblast activation. GRK5 is highly expressed and active in cardiac fibroblasts; however, its pathophysiological role in these crucial cardiac cells is unknown. We demonstrate using adult cardiac fibroblasts that genetic deletion of GRK5 inhibits angiotensin II (AngII)-mediated fibroblast activation. Fibroblast-specific deletion of GRK5 in mice led to decreased fibrosis and cardiac hypertrophy after chronic AngII infusion or after ischemic injury compared to nontransgenic littermate controls (NLCs). Mechanistically, we show that nuclear translocation of GRK5 is involved in fibroblast activation. These data demonstrate that GRK5 is a regulator of fibroblast activation in vitro and cardiac fibrosis in vivo. This adds to previously published data which demonstrate the potential beneficial effects of GRK5 inhibition in the context of cardiac disease.

Trend change of the transmission route of COVID-19-related symptoms in Japan

OBJECTIVES

The Japanese prime minister declared a state of emergency on April 7 2020 to combat the outbreak of coronavirus disease 2019 (COVID-19). This declaration was unique in the sense that it was essentially driven by the voluntary restraint of the residents. We examined the change of the infection route by investigating contact experiences with COVID-19-positive cases.

STUDY DESIGN

This study is a population-level questionnaire-based study using a social networking service (SNS).

METHODS

To assess the impact of the declaration, this study used population-level questionnaire data collected from an SNS with 121,375 respondents (between March 27 and May 5) to assess the change in transmission routes over the study period, which was measured by investigating the association between COVID-19-related symptoms and (self-reported) contact with COVID-19-infected individuals.

RESULTS

The results of this study show that the declaration prevented infections in the workplace, but increased domestic infections as people stayed at home. However, after April 24, workplace infections started to increase again, driven by the increase in community-acquired infections.

CONCLUSIONS

While careful interpretation is necessary because our data are self-reported from voluntary SNS users, these findings indicate the impact of the declaration on the change in transmission routes of COVID-19 over time in Japan.

The relationship between fever rate and telework implementation as a social distancing measure against the COVID-19 pandemic in Japan

Objectives

On March 28, the Japanese government decided on the “Basic Policies for Novel Coronavirus Disease Control” and called on the public to thoroughly implement social distancing measures (i.e., behavioral restrictions to limit the frequency and intensity of human contact), especially telework.

Methods

We used population-level questionnaire data from a social networking service (SNS), with 275,560 respondents from March 5 to April 6, to evaluate the relationship between telework implementation and the presence of a fever (body temperature higher than 37.5 °C) within 1 month as a surrogate indicator of COVID-19 infection, by occupation type and age-group.

Results

Among company employees, statistical significance was identified in the 15- to 29-year and 30- to 59-year age-groups, showing higher fever rates in the non-teleworker group (for the 15- to 29-year age-group, non-teleworkers: 7.64%; teleworkers: 6.45%; P = 0.02; for the 30- to 59-year age-group, non-teleworkers: 3.46%; teleworkers: 3.14%; P = 0.02).

Conclusions

Telework remains a controversial topic in Japan as the government called for emergency measures. Although caution is warranted in interpreting our findings because our data are limited to the voluntary SNS users, they will be essential to push forward with more measures to promote social distancing measures in the midst of Japan's current tense political climate.

Abstract 516: GRK5 Regulates Cardiac Fibroblast Differentiation and Fibrosis

Pathological remodeling of the heart is a hallmark of heart failure (HF) and these structural changes further perpetuate the disease. Cardiac fibroblasts are the critical cell type that is responsible for maintaining the structural integrity of the heart. Stress conditions, such as a myocardial infarction (MI), can activate and induce the transdifferentiation of quiescent fibroblasts into synthetic and contractile myofibroblasts. G protein-coupled receptor (GPCR) kinases (GRKs) are important mediators of cardiovascular homeostasis through dampening of GPCR signaling. GRK5 is one isoform of these kinases that is expressed in the heart and has been shown to be up-regulated in human HF. Of note, GRK5 has been demonstrated to translocate to the nucleus in cardiomyocytes in a calcium-calmodulin (Ca 2+ -CAM)-dependent manner, promoting hypertrophic gene transcription through activation of NFAT and NFκB. Interestingly, these transcription factors are also involved in fibroblast activation. GRK5 is highly expressed and active in cardiac fibroblasts (CFs), however its pathophysiological role in these crucial cardiac cells is unknown. Utilizing adult mouse CFs in vitro , our preliminary data suggests a relevant role for GRK5 in the activation of fibroblasts. We observed that genetic deletion of GRK5 (GRK5KO) in CFs attenuated α-smooth muscle actin (α-SMA) expression, a myofibroblast marker, after stimulation with Angiotensin II (AngII). In addition, deletion of GRK5 diminished the expression of myofibroblast genes and proteins such as Collagen I and III after AngII stimulation. GRK5KO CF’s were also refractory to AngII mediated collagen gel contraction and protein translation. In vivo , mice with fibroblast-specific deletion of GRK5 were protected against cardiac fibrosis and hypertrophy after AngII infusion and post-MI compared to wild type mice. Mechanistically, GRK5 translocates to the nucleus after AngII stimulation and pharmacological inhibition of this event (via inhibition of Ca 2+ -CAM) prevented AngII mediated fibroblast transdifferentiation. These data support the hypothesis that GRK5 is an essential regulator of fibroblast activation and could be a novel therapeutic target to decrease adverse myocardial remodeling after injury.

New Insights in Cardiac β-Adrenergic Signaling During Heart Failure and Aging

Heart failure (HF) has become increasingly common within the elderly population, decreasing their survival and overall quality of life. In fact, despite the improvements in treatment, many elderly people suffer from cardiac dysfunction (HF, valvular diseases, arrhythmias or hypertension-induced cardiac hypertrophy) that are much more common in an older fragile heart. Since β-adrenergic receptor (β-AR) signaling is abnormal in failing as well as aged hearts, this pathway is an effective diagnostic and therapeutic target. Both HF and aging are characterized by activation/hyperactivity of various neurohormonal pathways, the most important of which is the sympathetic nervous system (SNS). SNS hyperactivity is initially a compensatory mechanism to stimulate contractility and maintain cardiac output. Unfortunately, this chronic stimulation becomes detrimental and causes decreased cardiac function as well as reduced inotropic reserve due to a decrease in cardiac β-ARs responsiveness. Therapies which (e.g., β-blockers and physical activity) restore β-ARs responsiveness can ameliorate cardiac performance and outcomes during HF, particularly in older patients. In this review, we will discuss physiological β-adrenergic signaling and its alterations in both HF and aging as well as the potential clinical application of targeting β-adrenergic signaling in these disease processes.

New Insights in Cardiac β-Adrenergic Signaling During Heart Failure and Aging

Heart failure (HF) has become increasingly common within the elderly population, decreasing their survival and overall quality of life. In fact, despite the improvements in treatment, many elderly people suffer from cardiac dysfunction (HF, valvular diseases, arrhythmias or hypertension-induced cardiac hypertrophy) that are much more common in an older fragile heart. Since β-adrenergic receptor (β-AR) signaling is abnormal in failing as well as aged hearts, this pathway is an effective diagnostic and therapeutic target. Both HF and aging are characterized by activation/hyperactivity of various neurohormonal pathways, the most important of which is the sympathetic nervous system (SNS). SNS hyperactivity is initially a compensatory mechanism to stimulate contractility and maintain cardiac output. Unfortunately, this chronic stimulation becomes detrimental and causes decreased cardiac function as well as reduced inotropic reserve due to a decrease in cardiac β-ARs responsiveness. Therapies which (e.g., β-blockers and physical activity) restore β-ARs responsiveness can ameliorate cardiac performance and outcomes during HF, particularly in older patients. In this review, we will discuss physiological β-adrenergic signaling and its alterations in both HF and aging as well as the potential clinical application of targeting β-adrenergic signaling in these disease processes.

Abstract 262: GRK5 is a Novel Regulator of Fibroblast Activation

Pathological remodeling of the heart is a hallmark of heart failure (HF) and these structural changes of the heart further perpetuates the disease. Cardiac fibroblasts are the critical cell type that is responsible for maintaining the structural integrity of the heart. Stress conditions, such as a myocardial infarction, can activate and induce the transdifferentiation of quiescent fibroblasts into synthetic and contractile myofibroblasts. G protein-coupled receptor (GPCR) kinases (GRKs) are important mediators of cardiovascular homeostasis through dampening of GPCR signaling. Recently, non-canonical activities of these GRKs have been elucidated. GRK5 is one isoform of these kinases that is expressed in the heart and has been shown to be up-regulated in human HF. Of note, GRK5 has been demonstrated to translocate to the nucleus in cardiomyocytes, promoting hypertrophic gene transcription through activation of nuclear factor of activated T-cells (NFAT) and nuclear factor κB (NFκB). Interestingly, these transcription factors are also involved in fibroblast activation and transdifferentiation. GRK5 is highly expressed and active in cardiac fibroblasts, however its physiological and pathological role in these crucial cardiac cells is unknown. Utilizing adult mouse cardiac fibroblasts in vitro , our preliminary data suggests a relevant role for GRK5 in the activation and function of fibroblasts. We observed that genetic deletion of GRK5 in cardiac fibroblasts attenuated α smooth muscle actin (α-SMA) expression, a classical myofibroblast marker, after stimulation with Transforming Growth Factor β (TGFβ) and Angiotensin II (AngII). In addition, deletion of GRK5 diminished the expression of myofibroblast specific genes and proteins such as Collagen I and II after AngII stimulation and were refractory to TGFβ and AngII mediated collagen gel contraction. Conversely, GRK5 overexpression led to an increase in differentiation markers such as α-SMA. These data support the hypothesis that GRK5 is an essential regulator of fibroblast activation. GRK5 fibroblast knockout mice are currently being examined to determine if GRK5 regulates fibroblast transdifferentiation in vivo .

Myocardial pathology induced by aldosterone is dependent on non-canonical activities of G protein-coupled receptor kinases

Hyper-aldosteronism is associated with myocardial dysfunction including induction of cardiac fibrosis and maladaptive hypertrophy. Mechanisms of these cardiotoxicities are not fully understood. Here we show that mineralocorticoid receptor (MR) activation by aldosterone leads to pathological myocardial signalling mediated by mitochondrial G protein-coupled receptor kinase 2 (GRK2) pro-death activity and GRK5 pro-hypertrophic action. Moreover, these MR-dependent GRK2 and GRK5 non-canonical activities appear to involve cross-talk with the angiotensin II type-1 receptor (AT1R). Most importantly, we show that ventricular dysfunction caused by chronic hyper-aldosteronism in vivo is completely prevented in cardiac Grk2 knockout mice (KO) and to a lesser extent in Grk5 KO mice. However, aldosterone-induced cardiac hypertrophy is totally prevented in Grk5 KO mice. We also show human data consistent with MR activation status in heart failure influencing GRK2 levels. Therefore, our study uncovers GRKs as targets for ameliorating pathological cardiac effects associated with high-aldosterone levels.

SPG7 Is an Essential and Conserved Component of the Mitochondrial Permeability Transition Pore

Mitochondrial permeability transition is a phenomenon in which the mitochondrial permeability transition pore (PTP) abruptly opens, resulting in mitochondrial membrane potential (ΔΨm) dissipation, loss of ATP production, and cell death. Several genetic candidates have been proposed to form the PTP complex, however, the core component is unknown. We identified a necessary and conserved role for spastic paraplegia 7 (SPG7) in Ca(2+)- and ROS-induced PTP opening using RNAi-based screening. Loss of SPG7 resulted in higher mitochondrial Ca(2+) retention, similar to cyclophilin D (CypD, PPIF) knockdown with sustained ΔΨm during both Ca(2+) and ROS stress. Biochemical analyses revealed that the PTP is a heterooligomeric complex composed of VDAC, SPG7, and CypD. Silencing or disruption of SPG7-CypD binding prevented Ca(2+)- and ROS-induced ΔΨm depolarization and cell death. This study identifies an ubiquitously expressed IMM integral protein, SPG7, as a core component of the PTP at the OMM and IMM contact site.

Serial magnetic resonance imaging study of posterior cruciate ligament reconstruction or augmentation using hamstring tendons

PURPOSE

The purpose of this study was to analyze serial changes in the magnetic resonance imaging (MRI) signals of autograft hamstrings single bundle posterior cruciate ligament (PCL) reconstruction and the effects of remnant preservation (augmentation).

MATERIAL AND METHODS

Twenty-two isolated PCL injuries were arthroscopically reconstructed or augmented with hamstring tendons. MRI scans were obtained at 3, 6, and 12 months, and prior to the second-look arthroscopy (average 20.7 months). The patients were divided into 2 groups by remnant preservation: five PCL reconstructions after PCL remnant resection (Group Rec) (23%), and 17 reconstructions preserving the remnant (Group Aug) (77%). The 22 patients were also divided in two groups depending on the location of the PCL tear. There were 9 knees with proximal tear (Type P) (41%) and 13 knees with distal tear (Type D) (59%). The signal intensity and fiber continuity of 4 zones (proximal, middle, distal intra-articular and tibial tunnel zones) were evaluated by the Mariani score.

RESULTS

The average MRI evaluation score gradually increased from 6 months through the final MRI. The intra-articular part of the graft exhibited slower maturation (12 months - final scan) as compared with the tibial tunnel (6-12 months). The distal zone underwent better maturation than the proximal or middle zones at all points. In the proximal zone, the score for Group Aug was significantly higher than Group Rec. In the proximal zone, the Type D score with a proximally-preserved remnant was significantly higher than Type P without a proximal remnant.

CONCLUSIONS

The hamstring tendons require more than 1 year to achieve low-signal intensity. PCL remnant has a beneficial effect on the maturation of the hamstring graft.

LEVEL OF EVIDENCE IV

therapeutic case series.

Proprioceptive function after isolated single-bundle posterior cruciate ligament reconstruction with remnant preservation for chronic posterior cruciate ligament injuries

INTRODUCTION

Posterior cruciate ligament (PCL) reconstruction using the remnant preserving technique may contribute to improved postoperative posterior stability, graft healing, and proprioception recovery. Although there have been several reports on remnant preserving PCL reconstruction, no study has yet evaluated the proprioceptive functions before and after PCL reconstruction with remnant preservation. The purpose of this study is to retrospectively evaluate the clinical outcomes and proprioceptive function after isolated single-bundle PCL reconstruction with remnant preservation for chronic PCL injuries.

HYPOTHESIS

Isolated single-bundle PCL reconstruction with remnant preservation surgery for chronic PCL injuries provides satisfactory clinical outcomes and good recovery of the proprioceptive function.

METHODS

Nineteen patients who had undergone isolated single-bundle PCL reconstruction with remnant preservation for chronic PCL injuries were followed up for more than 2 years. The posterior laxity was measured by the gravity sag view, stress radiography and the KT-2000 knee arthrometer. The proprioceptive function was defined as the threshold to detect passive motion (TTDPM).

RESULTS

The average Lysholm score significantly improved from 63.7±13.2 preoperatively to 94.4±4.6 at final follow-up. The postoperative posterior laxity significantly improved. Regarding TTDPM, there were no significant differences between the preoperative score and the score at every given time point, regardless of the starting angles and the moving directions of the knees.

CONCLUSIONS

The proprioceptive function, defined as TTDPM, is maintained after single-bundle PCL reconstruction with remnant preservation, and the postoperative clinical scores and posterior laxity significantly improve.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Influence of trunk muscle co-contraction on spinal curvature during sitting cross-legged

In Asia, many activities of daily living (ADL) are performed while sitting cross-legged on the floor. This sitting posture rotates the pelvis in a more dorsal direction and lumbar lordosis is more flattened than while sitting on a chair. Sitting cross-legged induces a greater load on the intervertebral discs and spine, especially when in a slumped position that is known to increase disc pressure even more and to aggravate chronic low back pain (CLBP). Therefore, it is very important to instruct Asian people about the correct sitting posture. In addition, it is known that co-contraction of the deep spine-stabilizing muscles enhances lumbar segmental stability and the sacroiliac joint. However, little is known about the influence of co-contraction of the trunk deep muscles on spinal curvature while sitting cross-legged on the floor. The purpose of this study was to compare EMG (electromyographic) activity of the trunk muscles while slump cross-legged sitting with that during co-contraction of the trunk muscles and to investigate how this co-contraction influences spinal curvature. Ten healthy male volunteers (21.7 +/- 2.5 years old) without CLBP participated in the study. Bipolar surface electrodes were attached to the rectus abdominis, the obliquus externus abdominis, the obliquus internus abdominis, the lower back extensor muscles (L3) and the multifidus on the right side. EMG signals were continuously recorded while slump sitting cross-legged and during co-contraction of the trunk muscles. They were amplified, band-pass filtered, digitized and stored by a data acquisition system. The average muscle activity values over the five-second sample for each sitting posture were normalized to maximal voluntary contractions (%MVC). While the subjects performed both sitting postures, the curvature of the spine was measured using a skin-surface and hand-held device, the "Spinal Mouse". More significant activities of the trunk muscles, with the exception of the rectus abdominis, were observed during co-contraction of the trunk muscles than while slump sitting cross-legged. The co-contraction of the trunk muscles resulted in significantly less thoracic and lumbar curvature and more sacral angle than while slump sitting cross-legged. The results of this study indicated that co-contraction of the trunk muscles while sitting cross-legged could bring about the correct thoracic and lumbar curvature, and effectively stabilize the lumbopelvic region, and decrease focal stress on passive structures.

Adaptive changes in control of the head while lifting ten times

We often observe when workers lift objects, they tend to move their heads upward and back. Their movement may be an efficient habit, but little is known about control of the head while lifting. Our primary aim was to investigate the hypothesis that several repetitive liftings would lead to an increase in neck extension. Fifteen healthy male volunteers (20.9 +/- 0.8 years old) were asked to lift a case 10 times without instructions about the starting posture or lifting technique. Motion data and electromyography (EMG) signals were continuously recorded. The lifting time, angles of joints, and distance between the case and the malleolus lateralis at the moment of lifting were calculated from the motion data. EMG signals of the initial 1/10 phase of each lifting time were averaged and normalized to maximal voluntary contractions(% AEMG), and the mean frequencies were calculated by wavelet transform analysis. One-way analysis of variance and post hoc analysis were performed with Dunnett's test (p < 0.05). The cervical extension angle significantly increased, and the distance between the case and the malleolus lateralis significantly decreased for the later lifting times. The % AEMG of the gluteus maximus and the biceps femoris significantly increased for the later lifting times. A moving upward and back of the weight of the head, a decrease in the distance between the body and the case, and increases in tension of the hip extensor muscles could facilitate a righting movement to maintain balance. Therefore, paying attention to head control may be efficient while lifting.

Influence of trunk muscle co-contraction on spinal curvature during sitting reclining against the backrest of a chair

Today, many office workers frequently adopt a relaxed or slumped sitting posture for many hours, and often people tend to spend their leisure time reclining against the backrest of a chair while sitting for a long time, as when watching television. While sitting, the pelvis rotates backwardly, and lumbar lordosis is flattened. Simultaneously, the load on the intervertebral discs and spine increases. Sitting in a slumped position is known to increase disc pressure even more, and to aggravate chronic low back pain (CLBP). Therefore, it is very important to teach workers and often people about the correct sitting posture. In addition, it has been recognized that co-contraction of the deep spine-stabilizing muscles enhances lumbar segmental stability and the sacro-iliac joint. However, little is known about the influence of co-contraction of the trunk deep muscles on spinal curvature during sitting reclining against the backrest of a chair. The purpose of this study was to compare the EMG (electromyographic) activity of the trunk muscles during slump sitting with that during co-contraction and to investigate how this cocontraction influences spinal curvature. Ten healthy male volunteers (20.8 +/- 0.8 years old) without CLBP participated in the study. Bipolar surface electrodes were attached to the rectus abdominis, the obliquus externus abdominis, the obliquus internus abdominis, the lower back extensor muscles (L3) and the multifidus on the right side. The EMG signals were continuously recorded during slump sitting and co-contraction of the trunk muscles, reclining against the backrest of chair. They were amplified, band-pass filtered, digitized and stored by a data acquisition system. The average muscle activity values over the five-second sample for each sitting posture were normalized to maximal voluntary contractions (%MVC). While the subjects performed both sitting postures, the curvature of the spine was measured using a new skin-surface and hand-held device, the "Spinal Mouse". More significant activities of the trunk muscles, with the exception of the rectus abdominis and the lower back extensor muscles (L3), were observed during co-contraction of the trunk muscles than during slump sitting. The co-contraction of the trunk muscles resulted in significantly less lumbar curvature and more sacral angle than during slump sitting. The thoracic curvature showed no significant change during either sitting posture. The results of this study indicated that co-contraction of the trunk muscles during sitting reclining against the backrest of a chair could bring about the correct lumbar curvature, effectively stabilize the lumbopelvic region, and decrease focal stress on passive structures.

Influences of the position of the head on posture while lifting

In clinical training of some lower back pain patients, teaching them to control their lumbar lordosis during lifting may be difficult. Therefore, another effective method for lifting technique is required. In standing, head cannot move without some compensating postural adjustment. The purpose of this study was to examine the influence of head position on lifting posture. Fourteen healthy male volunteers (22.6 +/- 4.4 years old) lifted a case while maintaining two different head positions; a downward position and an upright position. In the upright position, activities of the latissimus dorsi and vastus lateralis significantly increased, and these of the biceps femoris significantly decreased during the initial 100 msec phase of lifting. There were no differences in the activities of the upper trapezius, lumbar extensor muscles (L3, L5), and obliquus abdominis under the two conditions. There were also no differences in the lumbar angle when the case was lifted. The flexion angles of the hip, knee, and ankle significantly increased, and the lumbar spine moved closer to the case. Lifting posture was influenced by the head position. Advantages included being able to shift loads on the body from the lower back to the legs, to move the lumbar spine closer to the case, and to relatively increase the moment of lumbar extension. The weight of the head as it moved upward and back, and the weight of the rear part of the body as it moved downward and forward helped to maintain balance.

Influence of trunk muscle co-contraction on spinal curvature during sitting for desk work

Nowadays, a lot of office workers are forced to sit at a desk for many hours while doing their jobs. While sitting, the pelvis rotates backwardly, and lumbar lordosis is flattened. At the same time, the load on the intervertebral discs and spine increases. Sitting in a slumped position is known to increase disc pressure even more, and to aggravate chronic low back pain (CLBP). Therefore, it is very important to teach workers about the correct sitting posture. In addition, it has been recognized that co-contraction of the deep spine-stabilizing muscles enhances lumbar segmental stability and the sacro-iliac joint. However, little is known about the influence of co-contraction of the trunk deep muscles on spinal curvature during sitting for while doing desk work. The purpose of this study was to compare EMG (electromyographic) activity of the trunk muscles during slump sitting with that during co-contraction of the trunk muscles and to investigate how this co-contraction influences spinal curvature. Ten healthy male volunteers (21.7 +/- 2.5 years old) without CLBP participated in the study. Bipolar surface electrodes were attached to the rectus abdominis, the obliquus externus abdominis, the obliquus internus abdominis, the lower back extensor muscles (L3) and the multifidus on the right side. EMG signals were continuously recorded during slump sitting and co-contraction of the trunk muscles, simulating a desk work sitting posture; i.e., slightly inclined forward. They were amplified, band-pass filtered, digitized and stored by a data acquisition system. The average muscle activity values over the five-second sample for each sitting posture were normalized to maximal voluntary contractions (%MVC). While the subjects performed both sitting postures, the curvature of the spine was measured using a new skin-surface and hand-held device, the "Spinal Mouse". More significant activities of the trunk muscles, with the exception of the rectus abdominis, were observed during co-contraction of the trunk muscles than during slump sitting The co-contraction of the trunk muscles resulted in significantly less lumbar curvature and more sacral angle than during slump sitting. The thoracic curvature showed no significant change during either sitting posture. The results of this study indicated that co-contraction of the trunk muscles during sitting while doing desk work could bring about the correct lumbar curvature, and effectively stabilize the lumbopelvic region, and decrease focal stress on passive structures.

Electromyographic activity of selected trunk muscles during bicycle ergometer exercise and walking

Recently, active treatment such as exercise has been increasingly advocated for CLBP (chronic low back pain). Specially, exercise to improve fitness has been recommended for the prevention of back injuries. The bicycle ergometer or walking have often been used to improve the fitness of CLBP patients. However, little is known about the activity levels of the trunk muscles during such exercise. In this study, the electromyographic (EMG) activities of the trunk muscles during bicycle ergometer exercises and walking were compared and the load level on these muscles during such exercises was investigated. The present study provides basic information concerning fitness exercise in CLBP patients. Eleven healthy male volunteers (21.7 +/- 2.5 years old) without low back pain participated in the study. Bipolar surface electrodes were attached to the right side of the rectus abdominis, the obliquus externus abdominis and lower back extensor muscles (L3). EMG signals were continuously recorded while walking and during gradual loading exercises and normalized to maximal voluntary contractions (% MVC). One way analysis of variance (ANOVA) was performed on the % MVC from each exercise and walking for each of the three trunk muscle sites (p < 0.05). The rectus abdominis muscle showed activity of about 6% MVC during any grade of exercise and walking and no significant differences were found between these forms of exercise. The obliquus externus abdominis muscle showed about 30% MVC during any grade of exercise and walking, but no significant difference was found between them. The low back muscles showed activity of about 12% MVC while walking, whereas activity level increased as the exercise load using the bicycle ergometer increased. More significant low back muscles activity was observed while walking than during exercises of 25 w and 50 w. The results of this study indicated that exercise using the bicycle ergometer should be useful for maintaining or improving fitness in CLBP patients, because it results in less load on the trunk muscles and relatively more oxygen uptake than walking.

Effect of static stretch on fatigue of lumbar muscles induced by prolonged contraction

Low back pain (LBP) is believed to be the result of fatigue of the back extensor muscles induced by prolonged contraction. Although static stretch has been considered to promote recovery from such muscle fatigue by relaxation, little is known about the effect of stretch on muscle fatigue, especially in the back extensor muscles. The purpose of this study was to investigate the effect of static stretch on prolonged contraction-inducedfatigue of the back extensor muscles using electromyographic (EMG) spectral analysis in ten healthy volunteers. Bipolar surface electrodes were placed on the longissimus and the multifidus muscles. EMG signals were collected during two trials of a Sorensen trunk-holding test for two minutes, with a five-minute rest period between the two trials (control test). All subjects were asked to perform the same trials, with one-minute of static stretch and a four-minute rest period (stretch test). Maintaining the knees toward the chest in supine position resulted in static stretch. The median frequency (MF) was calculated using a spectrum analysis program, and the MF slope over time was computed by linear regression analysis, and normalized with the y-intercept. The decreasing rate of the normalized MF slope between two trials in two tests was compared. The decreasing rate of the normalized MF slope of the second trial was larger than that of the first trial in the control test (p < 0.05), but no significant difference was observed in the stretch test. The results indicated that static stretch had a significant effect on the recovery from fatigue of the back extensor muscles, since it influenced the decreasing rate of the normalized MF slope.

Protein transduction domain of HIV-1 Tat protein promotes efficient delivery of DNA into mammalian cells

The plasma membrane of mammalian cells is one of the tight barriers against gene transfer by synthetic delivery systems. Various agents have been used to facilitate gene transfer by destabilizing the endosomal membrane under acidic conditions, but their utility is limited, especially for gene transfer in vivo. In this article, we report that the protein transduction domain of human immunodeficiency virus type 1 Tat protein (Tat peptide) greatly facilitates gene transfer via membrane destabilization. We constructed recombinant lambda phage particles displaying Tat peptide on their surfaces and carrying mammalian marker genes as part of their genomes (Tat-phage). We demonstrate that, when animal cells are briefly exposed to Tat-phage, significant expression of phage marker genes is induced with no harmful effects to the cells. In contrast, recombinant phage displaying other functional peptides, such as the integrin-binding domain or a nuclear localization signal, could not induce detectable marker gene expression. The expression of marker genes induced by Tat-phage is not affected by endosomotropic agents but is partially impaired by inhibitors of caveolae formation. These data suggest that Tat peptide will become a useful component of synthetic delivery vehicles that promote gene transfer independently of the classical endocytic pathway.

Nuclear targeting of DNA

The nuclear membrane is a tight barrier for cytoplasmic proteins, but nuclear proteins have the intrinsic ability to overcome this barrier by an active signal-mediated process. Specific cytoplasmic carrier proteins have the responsibility to escort these proteins into the nucleus through the nuclear pore. The nuclear membrane is also a tight barrier for exogenous DNA delivered by synthetic vehicles, while many of the karyophilic viruses have a mechanism to actively deliver their genome through the nuclear pore. Virus DNA and RNA cannot move into the nucleus by themselves and require the viral structural proteins for efficient nuclear transport. In this article, we review the recent progress in understanding the mechanism of the nuclear transport of proteins and the virus genome, and discuss the possibility of developing synthetic gene-delivery systems based on these outcomes.

TRF1 is a critical trans-acting factor required for de novo telomere formation in human cells

The duplex telomere repeat (TTAGGG)(n) is an essential cis-acting element of the mammalian telomere, and an exogenous telomere repeat can induce chromosome breakage and de novo telomere formation at the site of a break (telomere seeding). Telomere seeding requires the telomere repeat (TTAGGG)(n) more stringently than does an in vitro telomerase assay, suggesting that it reflects the activity of a critical trans-acting element of the functional telomere, in addition to telomerase. Furthermore, telomere seeding is induced at a frequency fluctuating widely among human cell lines, suggesting variation in the activity of this hypothetical factor among cells. In this study, we investigated the cellular factor(s) required for telomere formation using the frequency of telomere seeding as an index and identified TRF1, one of the telomere repeat binding proteins, as an essential trans-acting factor. The exogenous telomere repeat induces telomere formation at a frequency determined by the availability of TRF1, even in telomerase-negative cells. Our study shows clearly that TRF1 has a novel physiological significance distinct from its role as a regulator of telomere length in the endogenous chromosome. The possible role of TRF1 in cell aging and immortalization is discussed.

A novel strategy for cancer therapy by mutated mammalian degenerin gene transfer

Mammalian degenerin (MDEG) is a member of the amiloride-sensitive sodium ion channel family, and its site-directed active mutant (MDEG-G430F) induces massive Na+ influx into cells, leading to cell ballooning and cell bursting. We attempted a novel therapeutic approach for gastric cancers by transferring MDEG-G430F into cancer cells using tumor-specific promoters. In carcinoembryonic antigen (CEA)-producing gastric cancer cells, the level of cell death observed when MDEG-G430F was used with a CEA promoter was similar to that observed when using a potent nonspecific promoter such as the cytomegalovirus promoter. In an in vivo study, fusogenic liposome complexes containing MDEG-G430F driven by the CEA promoter were injected intraperitoneally into CEA-producing gastric cancer cells in a mouse peritoneal dissemination model. Although all 15 of the control mice were dead by 50 days postinoculation, 13 of the 15 mice treated with MDEG-G430F survived. These results indicate that transferring MDEG-G430F into cancer tissues using tumor-specific promoters can achieve striking and selective cancer cell death irrespective of the transcriptional efficiency of the promoters used in vivo, and suggest that this approach is a promising new strategy for cancer gene therapy.

Effect of toluene inhalation on astrocytes and neurotrophic factor in rat brain

Toluene, an abused substance in Japan, is a neurotoxic chemical that has been shown to have neurobehavioral and electrophysiological effects. In previous work, both acute and chronic effects of toluene on cells have been studied extensively. However, although glial cells are thought to play an important role in the survival of neurons in the brain, the effect of toluene on glial cell function has not yet been characterized. To elucidate this, the effect of toluene inhalation on astrocytes in rat brain was examined. Toluene exposure (1500 ppm for 4 h on 4-10 days) augmented glial fibrillary acidic protein (GFAP) immunoreactivity, particularly in the hippocampus and cerebellum. Quantitative analysis showed that toluene inhalation markedly enhanced GFAP expression in the hippocampus and cerebellum. In both regions, proliferating cell nuclear antigen (PCNA) showed no obvious changes, but glutamine synthetase (GS)-immunoreactive cells were markedly increased by toluene exposure. Thus, the elevation of GFAP expression was induced by astrocyte activation rather than by cell proliferation. If toluene exposure activates astrocytes, astrocytes may play a role in the neurophysiological changes observed in toluene intoxication. A neurotrophic factor, basic fibroblast growth factor (b-FGF) was observed immunohistochemically in the capillary vessel walls in the hippocampus and the cerebellum of toluene-intoxicated rats. Basic-FGF may have induced GFAP expression both in the hippocampus and the cerebellum. So, other neurotrophic factors may affect the difference of GFAP elevation between the hippocampus and the cerebellum. These differences may relate to neurobehavioral function of each brain part after toluene exposure.

Identification and characterization of cell lines with a defect in a post-adsorption stage of Sendai virus-mediated membrane fusion

In the early stage of infection, Sendai virus delivers its genome into the cytoplasm by fusing the viral envelope with the cell membrane. Although the adsorption of virus particles to cell surface receptors has been characterized in detail, the ensuing complex process that leads to the fusion between the lipid bilayers remains mostly obscure. In the present study, we identified and characterized cell lines with a defect in the Sendai virus-mediated membrane fusion, using fusion-mediated delivery of fragment A of diphtheria toxin as an index. These cells, persistently infected with the temperature-sensitive variant Sendai virus, had primary viral receptors indistinguishable in number and affinity from those of parental susceptible cells. However, they proved to be thoroughly defective in the Sendai virus-mediated membrane fusion. We also found that viral HN protein expressed in the defective cells was responsible for the interference with membrane fusion. These results suggested the presence of a previously uncharacterized, HN-dependent intermediate stage in the Sendai virus-mediated membrane fusion.

HSP70 and c-Fos expression of brain stem hypoglossal nucleus in drowning

The brain stem hypoglossal nucleus (HN) is the center of nerves innervating the upper respiratory tract and is related to control of mastication, deglutition, speech and respiration. To elucidate the relationship between asphyxia and the HN, we investigated the change of hypoglossal neurons in cases of hanging, strangulation, smothering, choking, drowning and respiratory failure. Using immunohistochemical techniques, we observed the brain stem HN with antibodies against microtubule-associated protein 2 (MAP2), muscarinic acetylcholine receptor (mAChR), c-fos gene product (c-Fos) and 72 kD heat-shock protein (HSP70). MAP2, a cytoskeletal protein of the neuron, is a marker of neuronal damage. Muscarinic AChR was used as a marker of neuronal membrane and ACh signaling. We employed both HSP70 and c-Fos as markers of stress- or damage-related events. We measured the percentage of immunopositive neurons in total neurons of HN. Drowning produced higher expression of HSP70 and c-Fos than other causes of asphyxia, suggesting that drowning induces more severe damage in HN neurons. Furthermore, it was suspected that neuronal changes in drowning might relate to functions of the HN. These observations indicate that immunohistochemical examination of the brain stem HN could provide useful information for determining the cause of asphyxia.

Target-cell specificity of fusogenic liposomes: membrane fusion-mediated macromolecule delivery into human blood mononuclear cells

Fusogenic liposome, a unique vector prepared by fusing ultraviolet-inactivated Sendai virus and liposome, is known to efficiently deliver content into various animal cells through membrane fusion. In this study, we examined the target-cell specificity of fusogenic liposome (FL)-mediated macromolecule delivery into human blood cells using diphtheria toxin fragment A (DTA) as a probe. Among the peripheral blood mononuclear cells (PBMC), FL was able to deliver its encapsulates into CD14+ monocytes and CD4-/CD8- T-cells, but not into CD19+ B-lymphocytes, CD4+ T-cells or CD8+ T-cells. The susceptibility of human leukemia cell lines to FL was similar to that of PBMC; the order of the reactivity was U937 (monoblastic leukemia)>MOLT4, Jurkat (T-lymphoma)>Daudi, BALL1 (B-lymphoma)>K562 (erythroblastic leukemia). Interestingly, FL showed similar binding activity to all of these leukemia cell lines. These findings indicate that, among blood cells, monocytes, monoblastic leukemia cells, CD4-/CD8- T-cells and T-lymphoma cells are preferable targets for FL-mediated macromolecule delivery. This is the first demonstration of the existence of non-permissive cells against FL. Our results also suggest that some molecules on target-cells other than the binding targets of SV-derived protein may participate in fusion between FL and cells.

Gene delivery systems using the Sendai virus

Fusogenic liposome (FL) is a delivery system that can transfer encapsulated materials into living cells directly through membrane fusion. FL is a promising approach for gene therapy because it can deliver various genetic materials much more efficiently than other non-viral vectors without damaging the cell. FL-mediated gene transfer consists of two independent membrane fusion phenomena; generation of a FL by fusing a Sendai virus (SV) particle with a simple liposome encapsulating DNA, and successive fusion of the FL with cell membrane. The former requires viral F protein but no other special molecule on the liposomal membrane, whereas the latter may require the receptor (sialic acid) and unidentified assistant molecule(s) on the cell membrane. Further analysis suggests that these assistant molecule(s), not the receptor, may control the fusion and govern the cell specificity of FL-mediated delivery. This review has described a detailed analysis of these fusion phenomena and discussed possible applications of FL-mediated gene delivery to human gene therapy.

Gene transfer vectors based on Sendai virus

A gene delivery system is a fundamental technology used in human gene therapy. In order to treat patients suffering from incurable metabolic diseases, we must be able to deliver genes efficiently in situ and induce stable gene expression in non-dividing tissue cells. However, none of the current gene transfer systems (both viral and non-viral) satisfies this goal. In order to develop a novel gene delivery system that is free from the defects of existing gene transfer vectors, we analyzed natural biological phenomena that involve gene transfer and expression, and made artificial components that mimic the functioning of these systems. Our recent results shed light on three major aspects of gene transfer and expression: (1) the direct delivery of DNA into cytoplasm using fusogenic liposomes, (2) the transfer of DNA from cytoplasm to nucleus with a nuclear localization signal, and (3) the stabilization of DNA in the nucleus as an independent replicon. The possible development of a hybrid vector by combining these components is discussed.

Increase in the peripheral lymphocyte populations expressing CD54 (ICAM-1) after hyperthermic isolated limb perfusion in patients with malignant melanoma: an analysis of four cases

The lymphocytes isolated from perfused or non-perfused circulations before, during, and after hyperthermic isolated limb perfusion (HILP) in the four patients with malignant melanoma were analysed for the expression of CD54 (ICAM-1), CD58 (LFA-3), CD4, CD8, HLA class I and class II in order to investigate the mechanism(s) of the activation of such immunocompetent cells as natural killer (NK)-cells or T-lymphocytes by HILP. It was thus found that the lymphocyte populations expressing CD54 increased significantly 1 day after HILP in the four patients examined. The lymphocyte populations expressing CD58 apparently increased. It was also found that the NK-cell and T-lymphocyte activities increased during or after HILP in the present four cases as observed previously in the other melanoma patients. These results indicate that our HILP system may augment the immunological activities through the mechanisms of the induction of CD54 or CD58 expression in the peripheral lymphocytes of the melanoma patients who receive HILP.

[Clinical activity of native valve endocarditis]

We reviewed clinical course and surgical outcome of 31 patients with native valve endocarditis who underwent an operation between 1980 and 1994. In the present study, 15 patients who manifested a neurologic complication associated with endocarditis and/or those who had a periannular abscess were assigned as 'clinical active'. Comparing with non-active group (n = 16), clinical active group included more patients with increased C-reactive protein level and those with histological acute inflammatory reaction on excised valvular tissue. Optimal timing of the operation and surgical procedures for aortic root reconstruction were significant problems in the active group. Actuarial probability of survival at 5 postoperative year was 50.8 and 87.5% in the active and non-active group, respectively. The results suggest our 'clinical activity' is a useful predictor in patients with native valve endocarditis.

Synchronous multicentric development of hepatocellular carcinoma

Recently, the multicentric origin of hepatocellular carcinoma (HCC) has been recognized, but its clinical importance has still not yet been clarified. The histological characteristics of small hyperechoic HCCs coexisting in 44 consecutively resected Japanese patients whose main HCCs were < 5.0 cm in size were studied. Twelve small hyperechoic HCCs were found and classified into the following two groups: eight nodules in seven patients (15.9%) were early-stage HCC, and four nodules in four patients (9.1%) were more advanced HCC. Thus, early-stage HCC comprised 66.7% of the small echogenic HCCs. Eight HCCs detected as small hyperechoic lesions (found in 15.9% of the patients) showed varying degrees of fatty change yet proved to be well differentiated and retained the preexisting liver structure of either associated liver cirrhosis or chronic hepatitis. Moreover, the histologic characteristics of the eight early-stage HCCs were different from those of the main HCCs. In conclusion, approximately 15% of HCCs in Japanese patients may have a synchronous multicentric origin, and small hyperechoic lesions should be carefully evaluated. However, in the United States or other areas where the occurrence of fatty liver is common, that advice for small hyperechoic lesions may be overly cautious.

A valid new approach in treating solitary new lesions after resection of hepatocellular carcinoma

Recent studies have suggested that the appearance of solitary new lesions after a curative resection of hepatocellular carcinoma (HCC) may be closely related to the metachronous multicentric development of HCC. It is therefore extremely important to investigate the histological characteristics of solitary new nodular lesions confirmed to be HCC by an ultrasound (US)-guided needle biopsy. Thirty-five patients with small HCC, < or = 3 cm in diameter, who underwent a curative hepatic resection between 1987 and 1992, were observed for possible recurrence over a period of > or = 1 year. Solitary new lesions confirmed to be HCC were noted in 7 (20.0%) out of 35 cases 10-65 months after operation. All solitary new lesions underwent US-guided needle biopsy, and a histological examination of the biopsy specimen was performed. All seven solitary new lesions were then classified into the following two groups according to the histologic differentiation of biopsy specimens and were found to consist of five well-differentiated HCCs (71.4%) and two moderately differentiated HCCs (28.6%). Three of the five well-differentiated HCCs were accompanied by varying degrees of fatty changes. These morphologic observations suggest that approximately 70% of the solitary new lesions confirmed to be HCC after a curative resection of small HCC may thus be related to the metachronous multicentric origin of HCC. However, it is difficult to estimate the exact incidence of such cases. As a result, curative treatment may sometimes be feasible, even when treating solitary new lesions after resection of HCC. Therefore, we can better evaluate such solitary new nodular lesions after a resection of HCC by means of a histologic evaluation using US-guided needle biopsy.

Early stage hepatocellular carcinoma detected during intraoperative ultrasonography

OBJECTIVES

Recently, it has been recognized that there are increasing incidences of hepatocellular carcinoma (HCC) multicentricity. Thus, intraoperatively detected hepatic lesions that were once thought to be metastatic lesions now need to be carefully reexamined to determine whether they are true metastatic lesions or the multicentric development of HCC.

METHODS

We investigated the histological characteristics of small nodular lesions detected during intraoperative ultrasonography in 33 consecutive patients with small HCC who underwent laparotomy at our institution.

RESULTS

Fourteen nodular lesions were found incidentally in 10 of 33 patients (30.3%), and were classified into the following three groups: 11 nodules in nine patients (27.3%) were HCC, two nodules in two patients (6.1%) were hemangioma, and one nodule in one patient (3.0%) was a large regenerative nodule. HCC therefore comprised 78.6% of the intraoperatively detected nodular lesions. Of the 11 HCCs, six were hyperechoic, four were hypoechoic, and one was isoechoic. Five (83.3%) of six small hyperechoic HCCs and two (50.0%) of four hypoechoic HCCs were well differentiated and retained their preexisting liver structure. These findings closely coincide with the characteristics of early stage HCC. Thus, early stage HCC comprised 63.6% of the intraoperatively detected HCC cases.

CONCLUSIONS

A certain proportion of small satellite HCCs detected during intraoperative ultrasonography in patients with small HCC, which were previously thought to be metastatic lesions from the main HCC, may instead be early stage HCCs. Such findings would also support the concept of the multicentric development of HCC. Approximately 60% of all small HCC cases detected intraoperatively may be early stage HCC. As a result, it is predicted that the emergence of HCC is either multicentric or unicentric, with early intrahepatic spread, although the former seems to be more common.

[A case of early gastric cancer with Virchow's node metastasis, effectively treated by high dose of UFT]

We report a case of early gastric cancer with Virchow's node metastasis. The patient underwent partial gastrectomy and postoperative immunochemotherapy using MMC, 5'-DFUR and PSK, which reduced the Virchow's node. Three years after surgery, we found metastases to the left subclavicular and axillary nodes other than the Virchow's node. Then UFT was administered orally at 600 mg/day, and the metastatic nodes diminished, then vanished. The patient is alive nearly five years after surgery.

Multistep, multicentric, and simultaneous development of hepatocellular carcinoma

We resected a multiple hepatocellular carcinoma (HCC) which contained portal tracts, showed evidence of an early multistep condition, and a multicentric development of HCC which progressed simultaneously. A preoperative working examination revealed a tumor in S5 of the liver, which was 2.5 cm in diameter. In addition, a "nodule-in-nodule" appearance was seen on the ultrasonographic imaging. At intraoperative ultrasonography, an additional two HCCs were detected. At histologic examination of the resected specimen, the main nodule showed a nodule-in-nodule appearance. In the outer nodule, there was a well-differentiated HCC, while the portal tracts remained. The less-differentiated HCC grew in the inner nodule and was replacing the well-differentiated HCC in the outer nodule. These findings suggests morphological transition in the early stages of the multistep development of HCC. Two additional tumors (1.1 cm and 1.0 cm in diameter) detected at intraoperative ultrasonography proved to be HCCs (grade I) with marked fatty change, and with portal tracts remaining within both the HCCs. Furthermore, both of the HCCs retained their preexisting liver structure. These histologic findings coincided with the characteristics of the early stage HCC, whereas the coexistence of early stage HCCs suggests the multicentric development of HCC. Distortion, compression, and invasion of the portal tracts may appear as the tumor grows, thereby evoking an increasing risk of metastasis via the portal tracts. Therefore, the early diagnosis and treatment of HCC before the portal tracts disappear, when 1.5 cm in size or less, may be very important for surgeons and diagnosticians, as an effective curative resection may be feasible.

Pathomorphologic study of pale bodies in hepatocellular carcinoma

Pathomorphological and immunohistochemical studies were conducted on cases of hepatocellular carcinoma (HCC) with pale bodies (PB). HCC containing PBs was seen in 6 (5.7%) of 106 consecutively resected HCC cases. It was of interest that varying degrees of sclerotic change were found in 4 of the 6 cases and a certain correlation between PBs and sclerotic change of HCC tissue was suggested. Histologically, PBs were identified as a pale amorphous substance with a distinct margin and most of PBs occupied the entire cytoplasm of the cancer cells. PBs were practically negative for periodic-acid Schiff, and were also negative for phosphotungstic acid hematoxylin and orcein stains. Ultrastructurally, PBs were found to be a mass of granular or fibrillar materials having a single-layered limiting membrane, and dilated rough endoplasmic reticular (rER) were also found in the vicinity of PBs, suggesting the presence of a close relationship between rough endoplasmic reticula and PBs. Most PBs were found to be strongly positive for anti-fibrinogen antibody and some of them were weakly positive for anti-albumin, but were solely negative for other antibodies such as anti-HBs antigen, anti-alpha-1-antitrypsin, and anti-ferritin. According to those findings, PBs were thought to be fibrinogens accumulating in cystic rER due to a defective intracellular transport or an excretion disturbance.

Adenomatous hyperplasia in the vicinity of small hepatocellular carcinoma

The nodular lesions seen in the noncancerous areas of the 80 consecutively resected small hepatocellular carcinoma associated with cirrhosis were pathomorphologically studied. A total of 51 nodular lesions were found, and they were classified into the following four groups: large regenerative nodule (30 nodules), adenomatous hyperplasia (12 nodules), atypical adenomatous hyperplasia (4 nodules) and adenomatous hyperplasia containing cancerous foci (5 nodules). Grossly, all large regenerative nodules were well demarcated, but some of the adenomatous hyperplasia group were vaguely nodular. Atypical adenomatous hyperplasia and adenomatous hyperplasia containing cancerous foci accounted for 43% of the adenomatous hyperplasia group found in the vicinity of the 16 resected hepatocellular carcinoma (20%) out of 80 cases. The mean size (+/- S.D.) of the adenomatous hyperplasias containing cancerous foci, 15.8 +/- 2.2 mm, was significantly larger than 10.1 +/- 2.6 mm of the adenomatous hyperplasias p less than 0.01). All adenomatous hyperplasias containing cancerous foci and 75% of the atypical adenomatous hyperplasias demonstrated a marked fatty change, but none of the large regenerative nodules were accompanied by any fatty changes. This study demonstrated the morphological transition from adenomatous hyperplasia to hepatocellular carcinoma that was suggestive of multistep hepatocarcinogenesis. As a result, it is predicted that approximately 20% of all hepatocellular carcinomas may have the potential for being of multicentric origin and that approximately 40% of adenomatous hyperplasias may undergo malignant transformation, but it is difficult to estimate the exact number of incidences. The presence of varying degrees of fatty change may be one of the significant morphological markers for a malignant transformation from adenomatous hyperplasia to hepatocellular carcinoma.(ABSTRACT TRUNCATED AT 250 WORDS)

High rate of portal thrombosis after splenectomy in patients with esophageal varices and idiopathic portal hypertension

Data on 126 consecutive patients who were admitted to our clinics from January 1979 to May 1989 were scrutinized to assess changes in portal hemodynamics following splenectomy. Two groups were classified: (1) a group of 106 patients with cirrhosis of the liver and (2) a group of 20 patients with idiopathic portal hypertension (IPH). Portal thrombosis was present in five (25.0%) of the 20 patients with IPH and in two (1.8%) of the 106 patients with cirrhosis of the liver. As seen on celiac arteriography, the mean (+/- SD) diameter of the trunk of the splenic artery and vein was 8.99 +/- 1.55 and 16.2 +/- 3.6 mm, respectively, in patients with IPH, while it was 7.94 +/- 1.28 and 14.2 +/- 3.1 mm, respectively, in patients with cirrhosis of the liver. Changes in portal venous pressure were 78.4 +/- 59.4 mm H2O in patients with IPH and 43.5 +/- 38.7 mm H2O in patients with cirrhosis of the liver. There were no significant differences in the maximum level of thrombocytes in patients with IPH or in those patients with cirrhosis of the liver. These events suggest that portal thrombosis can occur with a significantly higher incidence in patients with IPH than in those patients with cirrhosis of the liver after splenectomy, and a decrease in blood flow in the portal vein may be closely linked to the formation of portal thrombosis after splenectomy in patients with IPH. Preoperative examination of portal hemodynamics must be thorough.

Health concerns of parents of school-aged children in Japan

"The study described in this paper was one of the first systematic attempts to identify the verbalized health concerns of parents of school-age children in Japan and provided some viable data for initiating the development of relevant health curriculum".