A loop extrusion-independent mechanism contributes to condensin I-mediated chromosome shaping

Condensin I is a five-subunit protein complex that is central to mitotic chromosome assembly in eukaryotic cells. Despite recent progress, its molecular mechanisms of action remain to be fully elucidated. By using Xenopus egg extracts as a functional assay, we find that condensin I complexes harboring mutations in its kleisin subunit CAP-H produce chromosomes with confined axes in the presence of topoisomerase IIα (topo IIα) and highly compact structures (termed “beans”) with condensin-positive central cores in its absence. The bean phenotype depends on the SMC ATPase cycle and can be reversed by subsequent addition of topo IIα. The HEAT repeat subunit CAP-D2, but not CAP-G, is essential for the bean formation. Notably, loop extrusion activities of the mutant complexes cannot explain the chromosomal defects they exhibit in Xenopus egg extracts, implying that a loop extrusion–independent mechanism contributes to condensin I–mediated chromosome assembly and shaping. We provide evidence that condensin–condensin interactions underlie these processes.

Comparison of All Solid Cancer Mortality and Incidence Dose-Response in the Life Span Study of Atomic Bomb Survivors, 1958-2009

Recent analysis of all solid cancer incidence (1958-2009) in the Life Span Study (LSS) revealed evidence of upward curvature in the radiation dose response among males but not females. Upward curvature in sex-averaged excess relative risk (ERR) for all solid cancer mortality (1950-2003) was also observed in the 0-2 Gy dose range. As reasons for non-linearity in the LSS are not completely understood, we conducted dose-response analyses for all solid cancer mortality and incidence applying similar methods [1958-2009 follow-up, DS02R1 doses, including subjects not-in-city (NIC) at the time of the bombing] and statistical models. Incident cancers were ascertained from Hiroshima and Nagasaki cancer registries, while cause of death was ascertained from death certificates throughout Japan. The study included 105,444 LSS subjects who were alive and not known to have cancer before January 1, 1958 (80,205 with dose estimates and 25,239 NIC subjects). Between 1958 and 2009, there were 3.1 million person-years (PY) and 22,538 solid cancers for incidence analysis and 3.8 million PY and 15,419 solid cancer deaths for mortality analysis. We fitted sex-specific ERR models adjusted for smoking to both types of data. Over the entire range of doses, solid cancer mortality dose-response exhibited a borderline significant upward curvature among males (P = 0.062) and significant upward curvature among females (P = 0.010); for solid cancer incidence, as before, we found a significant upward curvature among males (P = 0.001) but not among females (P = 0.624). The sex difference in magnitude of dose-response curvature was statistically significant for cancer incidence (P = 0.017) but not for cancer mortality (P = 0.781). The results of analyses in the 0-2 Gy range and restricted lower dose ranges generally supported inferences made about the sex-specific dose-response shape over the entire range of doses for each outcome. Patterns of sex-specific curvature by calendar period (1958-1987 vs. 1988-2009) and age at exposure (0-19 vs. 20-83) varied between mortality and incidence data, particularly among females, although for each outcome there was an indication of curvature among 0-19-year-old male survivors in both calendar periods and among 0-19-year-old female survivors in the recent period. Collectively, our findings indicate that the upward curvature in all solid cancer dose response in the LSS is neither specific to males nor to incidence data; its evidence appears to depend on the composition of sites comprising all solid cancer group and age at exposure or time. Further follow up and site-specific analyses of cancer mortality and incidence will be important to confirm the emerging trend in dose-response curvature among young survivors and unveil the contributing factors and sites.

Opening of cohesin's SMC ring is essential for timely DNA replication and DNA loop formation

The ring-shaped cohesin complex topologically binds to DNA to establish sister chromatid cohesion. This topological binding creates a structural obstacle to genome-wide chromosomal events, such as replication. Here, we examine how conformational changes in cohesin circumvent being an obstacle in human cells. We show that ATP hydrolysis-driven head disengagement, leading to the structural maintenance of chromosome (SMC) ring opening, is essential for the progression of DNA replication. Closure of the SMC ring stalls replication in a checkpoint-independent manner. The SMC ring opening also facilitates sister chromatid resolution and chromosome segregation in mitosis. Single-molecule analyses reveal that forced closure of the SMC ring suppresses the translocation of cohesin on DNA as well as the formation of stable DNA loops. Our results suggest that the ATP hydrolysis-driven SMC ring opening makes topologically bound cohesin dynamic on DNA to achieve replication-dependent cohesion in the S phase and to resolve cohesion in mitosis. Thus, the SMC ring opening could be a fundamental mechanism to modulate both cohesion and higher-order genome structure.

Individual response of humans to ionising radiation: governing factors and importance for radiological protection

Tissue reactions and stochastic effects after exposure to ionising radiation are variable between individuals but the factors and mechanisms governing individual responses are not well understood. Individual responses can be measured at different levels of biological organization and using different endpoints following varying doses of radiation, including: cancers, non-cancer diseases and mortality in the whole organism; normal tissue reactions after exposures; and, cellular endpoints such as chromosomal damage and molecular alterations. There is no doubt that many factors influence the responses of people to radiation to different degrees. In addition to the obvious general factors of radiation quality, dose, dose rate and the tissue (sub)volume irradiated, recognized and potential determining factors include age, sex, life style (e.g., smoking, diet, possibly body mass index), environmental factors, genetics and epigenetics, stochastic distribution of cellular events, and systemic comorbidities such as diabetes or viral infections. Genetic factors are commonly thought to be a substantial contributor to individual response to radiation. Apart from a small number of rare monogenic diseases such as ataxia telangiectasia, the inheritance of an abnormally responsive phenotype among a population of healthy individuals does not follow a classical Mendelian inheritance pattern. Rather it is considered to be a multi-factorial, complex trait.

The effects of high glucose condition on rat tenocytes in vitro and rat Achilles tendon in vivo

Objectives

The aim of this study was to investigate the effect of hyperglycaemia on oxidative stress markers and inflammatory and matrix gene expression within tendons of normal and diabetic rats and to give insights into the processes involved in tendinopathy.

Methods

Using tenocytes from normal Sprague-Dawley rats, cultured both in control and high glucose conditions, reactive oxygen species (ROS) production, cell proliferation, messenger RNA (mRNA) expression of NADPH oxidase (NOX) 1 and 4, interleukin-6 (IL-6), matrix metalloproteinase (MMP)-2, tissue inhibitors of matrix metalloproteinase (TIMP)-1 and -2 and type I and III collagens were determined after 48 and 72 hours in vitro. In an in vivo study, using diabetic rats and controls, NOX1 and 4 expressions in Achilles tendon were also determined.

Results

In tenocyte cultures grown under high glucose conditions, gene expressions of NOX1, MMP-2, TIMP-1 and -2 after 48 and 72 hours, NOX4 after 48 hours and IL-6, type III collagen and TIMP-2 after 72 hours were significantly higher than those in control cultures grown under control glucose conditions. Type I collagen expression was significantly lower after 72 hours. ROS accumulation was significantly higher after 48 hours, and cell proliferation after 48 and 72 hours was significantly lower in high glucose than in control glucose conditions. In the diabetic rat model, NOX1 expression within the Achilles tendon was also significantly increased.

Conclusion

This study suggests that high glucose conditions upregulate the expression of mRNA for NOX1 and IL-6 and the production of ROS. Moreover, high glucose conditions induce an abnormal tendon matrix expression pattern of type I collagen and a decrease in the proliferation of rat tenocytes.

Cite this article: Y. Ueda, A. Inui, Y. Mifune, R. Sakata, T. Muto, Y. Harada, F. Takase, T. Kataoka, T. Kokubu, R. Kuroda. The effects of high glucose condition on rat tenocytes in vitro and rat Achilles tendon in vivo. Bone Joint Res 2018;7:362–372. DOI: 10.1302/2046-3758.75.BJR-2017-0126.R2

Efficacy of protocol-based pharmacotherapy management on anticoagulation with warfarin for patients with cardiovascular surgery

WHAT IS KNOWN AND OBJECTIVE

Anticoagulation therapy with warfarin requires periodic monitoring of prothrombin time-international normalized ratio (PT-INR) and adequate dose adjustments based on the data to minimize the risk of bleeding and thromboembolic events. In our hospital, we have developed protocol-based pharmaceutical care, which we called protocol-based pharmacotherapy management (PBPM), for warfarin therapy. The protocol requires pharmacists to manage timing of blood sampling for measuring PT-INR and warfarin dosage determination based on an algorithm. This study evaluated the efficacy of PBPM in warfarin therapy by comparing to conventional pharmaceutical care.

METHODS

From October 2013 to June 2015, a total of 134 hospitalized patients who underwent cardiovascular surgeries received post-operative warfarin therapy. The early series of patients received warfarin therapy as the conventional care (control group, n=77), whereas the latter received warfarin therapy based on the PBPM (PBPM group, n=68). These patients formed the cohort of the present study and were retrospectively analysed.

RESULTS

The indications for warfarin included aortic valve replacement (n=56), mitral valve replacement (n=4), mitral valve plasty (n=22) and atrial fibrillation (n=29). There were no differences in patients' characteristics between both groups. The percentage time in therapeutic range in the first 10 days was significantly higher in the PBPM group (47.1%) than that in the control group (34.4%, P<.005). The average time to reach the steady state was significantly (P<.005) shorter in the PBPM group compared to the control group (7.3 vs 8.6 days).

WHAT IS NEW AND CONCLUSION

Warfarin therapy based on our novel PBPM was clinically safe and resulted in significantly better anticoagulation control compared to conventional care.

DS02R1: Improvements to Atomic Bomb Survivors' Input Data and Implementation of Dosimetry System 2002 (DS02) and Resulting Changes in Estimated Doses

Individual dose estimates calculated by Dosimetry System 2002 (DS02) for the Life Span Study (LSS) of atomic bomb survivors are based on input data that specify location and shielding at the time of the bombing (ATB). A multi-year effort to improve information on survivors' locations ATB has recently been completed, along with comprehensive improvements in their terrain shielding input data and several improvements to computational algorithms used in combination with DS02 at RERF. Improvements began with a thorough review and prioritization of original questionnaire data on location and shielding that were taken from survivors or their proxies in the period 1949-1963. Related source documents varied in level of detail, from relatively simple lists to carefully-constructed technical drawings of structural and other shielding and surrounding neighborhoods. Systematic errors were reduced in this work by restoring the original precision of map coordinates that had been truncated due to limitations in early data processing equipment and by correcting distortions in the old (WWII-era) maps originally used to specify survivors' positions, among other improvements. Distortion errors were corrected by aligning the old maps and neighborhood drawings to orthophotographic mosaics of the cities that were newly constructed from pre-bombing aerial photographs. Random errors that were reduced included simple transcription errors and mistakes in identifying survivors' locations on the old maps. Terrain shielding input data that had been originally estimated for limited groups of survivors using older methods and data sources were completely re-estimated for all survivors using new digital terrain elevation data. Improvements to algorithms included a fix to an error in the DS02 code for coupling house and terrain shielding, a correction for elevation at the survivor's location in calculating angles to the horizon used for terrain shielding input, an improved method for truncating high dose estimates to 4 Gy to reduce the effect of dose error, and improved methods for calculating averaged shielding transmission factors that are used to calculate doses for survivors without detailed shielding input data. Input data changes are summarized and described here in some detail, along with the resulting changes in dose estimates and a simple description of changes in risk estimates for solid cancer mortality. This and future RERF publications will refer to the new dose estimates described herein as "DS02R1 doses."

Effects of platelet-rich plasma and triamcinolone acetonide on interleukin-1ß-stimulated human rotator cuff-derived cells

Objectives

Triamcinolone acetonide (TA) is widely used for the treatment of rotator cuff injury because of its anti-inflammatory properties. However, TA can also produce deleterious effects such as tendon degeneration or rupture. These harmful effects could be prevented by the addition of platelet-rich plasma (PRP), however, the anti-inflammatory and anti-degenerative effects of the combined use of TA and PRP have not yet been made clear. The objective of this study was to determine how the combination of TA and PRP might influence the inflammation and degeneration of the rotator cuff by examining rotator cuff-derived cells induced by interleukin (IL)-1ß.

Methods

Rotator cuff-derived cells were seeded under inflammatory stimulation conditions (with serum-free medium with 1 ng/ml IL-1ß for three hours), and then cultured in different media: serum-free (control group), serum-free + TA (0.1mg/ml) (TA group), serum-free + 10% PRP (PRP group), and serum-free + TA (0.1mg/ml) + 10% PRP (TA+PRP group). Cell morphology, cell viability, and expression of inflammatory and degenerative mediators were assessed.

Results

Exposure to TA significantly decreased cell viability and changed the cell morphology; these effects were prevented by the simultaneous administration of PRP. Compared with the control group, expression levels of inflammatory genes and reactive oxygen species production were reduced in the TA, PRP, and TA+PRP groups. PRP significantly decreased the expression levels of degenerative marker genes.

Conclusions

The combination of TA plus PRP exerts anti-inflammatory and anti-degenerative effects on rotator cuff-derived cells stimulated by IL-1ß. This combination has the potential to relieve the symptoms of rotator cuff injury.

Cite this article: T. Muto, T. Kokubu, Y. Mifune, A. Inui, R. Sakata, Y. Harada, F. Takase, M. Kurosaka. Effects of platelet-rich plasma and triamcinolone acetonide on interleukin-1ß-stimulated human rotator cuff-derived cells. Bone Joint Res 2016;5:602–609. DOI: 10.1302/2046-3758.512.2000582.

Association of Acute Radiation Syndrome and Rain after the Bombings in Atomic Bomb Survivors

Acute radiation-induced symptoms reported in survivors after the atomic bombings in Hiroshima and Nagasaki have been suspected to be associated with rain that fell after the explosions, but this association has not been evaluated in an epidemiological study that considers the effects of the direct dose from the atomic bombs and other factors. The aim of this study was to evaluate this association using information from a fixed cohort, comprised of 93,741 members of the Life Span Study who were in the city at the time of the bombing. Information on acute symptoms and exposure to rain was collected in surveys conducted by interviewers, primarily in the 1950s. The proportion of survivors developing severe epilation was around 60% at levels of direct radiation doses of 3 Gy or higher and less than 0.2% at levels <0.005 Gy regardless of reported rain exposure status. The low prevalence of acute symptoms at low direct doses indicates that the reported fallout rain was not homogeneously radioactive at a level sufficient to cause a substantial probability of acute symptoms. We observed that the proportion of reported acute symptoms was slightly higher among those who reported rain exposure in some subgroups, however, suggestions that rain was the cause of these reported symptoms are not supported by analyses specific to the known areas of radioactive fallout. Misclassification of exposure and outcome, including symptoms due to other causes and recall bias, appears to be a more plausible explanation. However, the insufficient and retrospective nature of the available data limited our ability to quantify the attribution to those possible causes.

Initial Report for the Radiation Effects Research Foundation F1 Mail Survey

To study the full health effects of parental radiation exposure on the children of the atomic bomb survivors, the Radiation Effects Research Foundation developed a cohort of 76,814 children born to atomic bomb survivors (F1 generation) to assess cancer incidence and mortality from common adult diseases. In analyzing radiationassociated health information, it is important to be able to adjust for sociodemographic and lifestyle variations that may affect health. In order to gain this and other background information on the F1 cohort and to determine willingness to participate in a related clinical study, the F1 Mail Survey Questionnaire was designed with questions corresponding to relevant health, sociodemographic, and lifestyle indicators. Between the years 2000 and 2006, the survey was sent to a subset of the F1 Mortality Cohort. A total of 16,183 surveys were completed and returned: 10,980 surveys from Hiroshima residents and 5,203 from Nagasaki residents. The response rate was 65.6%, varying somewhat across parental exposure category, city, gender, and year of birth. Differences in health and lifestyle were noted in several variables on comparison across city and gender. No major differences in health, lifestyle, sociodemographics, or disease were seen across parental exposure categories, though statistically significant tests for heterogeneity and linear trend revealed some possible changes with dose. The data described herein provide a foundation for studies in the future.

A report from the 2013 international symposium: the evaluation of the effects of low-dose radiation exposure in the life span study of atomic bomb survivors and other similar studies

The RERF International Low-Dose Symposium was held on 5-6 December 2013 at the RERF campus in Hiroshima, Japan, to discuss the issues facing the Life Span Study (LSS) and other low-dose studies. Topics included the current status of low-dose risk detection, strategies for low-dose epidemiological and statistical research, methods to improve communication between epidemiologists and biologists, and the current status of radiological studies and tools. Key points made by the participants included the necessity of pooling materials over multiple studies to gain greater insight where data from single studies are insufficient; generating models that reflect epidemiological, statistical, and biological principles simultaneously; understanding confounders and effect modifiers in the current data; and taking into consideration less studied factors such as the impact of dose rate. It is the hope of all participants that this symposium be used as a trigger for further studies, especially those using pooled data, in order to reach a greater understanding of the health effects of low-dose radiation.

Dose- and time-dependent effects of triamcinolone acetonide on human rotator cuff-derived cells

Objectives

To investigate the appropriate dose and interval for the administration of triamcinolone acetonide (TA) in treating tendinopathy to avoid adverse effects such as tendon degeneration and rupture.

Methods

Human rotator cuff-derived cells were cultured using three media: regular medium (control), regular medium with 0.1 mg/mL of TA (low TA group), and with 1.0 mg/mL of TA (high TA group). The cell morphology, apoptosis, and viability were assessed at designated time points.

Results

In the low TA group, the cells became flattened and polygonal at seven days then returned to normal at 21 days. The cell apoptosis ratio and messenger ribonucleic acid expression of caspase-3, 7, 8, and 9 increased, and viability was reduced in the low and high groups at seven days. In the low TA group, apoptosis and viability returned to normal at 21 days, however, in the high TA group, the cell morphology, apoptosis ratio, caspase-3, 7, 8, and 9 and viability did not return by day 21. Re-administration was performed in the low TA group at 7-, 14-, and 21-day intervals, and cell viability did not return to the control level at the 7- and 14-day intervals.

Conclusion

A 0.1 mg/mL dose of TA temporarily decreased cell viability and increased cell apoptosis, which was recovered at 21 days, however, 1 mg/mL of TA caused irreversible damage to cell morphology and viability. An interval > three weeks was needed to safely re-administer TA. These findings may help determine the appropriate dose and interval for TA injection therapy.

Cite this article: Bone Joint Res 2014;3:328–34.

Impact of smoking on mortality and life expectancy in Japanese smokers: a prospective cohort study

OBJECTIVE

To investigate the impact of smoking on overall mortality and life expectancy in a large Japanese population, including some who smoked throughout adult life.

DESIGN

The Life Span Study, a population-based prospective study, initiated in 1950.

SETTING

Hiroshima and Nagasaki, Japan.

PARTICIPANTS

Smoking status for 27,311 men and 40,662 women was obtained during 1963-92. Mortality from one year after first ascertainment of smoking status until 1 January 2008 has been analysed.

MAIN OUTCOME MEASURES

Mortality from all causes in current, former, and never smokers.

RESULTS

Smokers born in later decades tended to smoke more cigarettes per day than those born earlier, and to have started smoking at a younger age. Among those born during 1920-45 (median 1933) and who started smoking before age 20 years, men smoked on average 23 cigarettes/day, while women smoked 17 cigarettes/day, and, for those who continued smoking, overall mortality was more than doubled in both sexes (rate ratios versus never smokers: men 2.21 (95% confidence interval 1.97 to 2.48), women 2.61 (1.98 to 3.44)) and life expectancy was reduced by almost a decade (8 years for men, 10 years for women). Those who stopped smoking before age 35 avoided almost all of the excess risk among continuing smokers, while those who stopped smoking before age 45 avoided most of it.

CONCLUSIONS

The lower smoking related hazards reported previously in Japan may have been due to earlier birth cohorts starting to smoke when older and smoking fewer cigarettes per day. In Japan, as elsewhere, those who start smoking in early adult life and continue smoking lose on average about a decade of life. Much of the risk can, however, be avoided by giving up smoking before age 35, and preferably well before age 35.

[Cardiovascular surgery for patient with pulmonary dysfunction]

Pulmonary dysfunction is one of the major factors for postoperative pulmonary complication. Preoperative pulmonary function test reveals possible operative risk. Particularly, in the patient with stage Ⅲ and Ⅳ chronic obstructive pulmonary disease (COPD), open heart surgery with cardiopulmonary bypass is at higher risk of complication. In these patients, safe and reliable surgical procedures are required. Preoperatively, quitting smoking and incentive spirometry can reduce the risk of pulmonary complications. Furthermore, noninvasive positive pressure ventilation (NPPV) on the appropriate indication can help to improve the outcome in the patients with pulmonary dysfunction.

Simultaneous genotyping of alcohol dehydrogenase 2 and aldehyde dehydrogenase 2 by single‐strand conformation polymorphism analysis

Alcohol dehydrogenase (ADH; EC 1.1.1.1) and aldehyde dehydrogenase (ALDH; EC 1.2.1.3) have important roles in the elimination of ingested ethanol. These enzymes have polymorphisms resulting from single-point mutations that cause kinetic differences in their respective enzyme activities. Simultaneous observation of these enzymes would be useful in investigating the association between these enzyme polymorphisms and alcohol-related problems. In this study amplified genomic DNA was amplified from nail clippings with two sets of primers for ADH2 and ALDH2 genes, respectively, in a micro test tube and the accuracy of the amplification was verified by direct sequencing. The PCR products were separated into four distinct bands by single-strand conformation polymorphism analysis. This genotyping method is fast, accurate. reliable and inexpensive, and requires the same amount of template DNA as non-simultaneous methods. In other words, the required amount of template DNA for this method is only half that required for the separate genotyping of ADH2 and ALDH2.

[New technology of intraaortic balloon pumping device]

Intraaortic balloon pumping (IABP) is the most popular circulatory assist device in cardiac surgery. In the development of IABP several modifications have been made. First, reduction in the caliber to 6 Fr is the most important modification of the IABP catheter to relatively small Japanese patients. Second, direct pressure measurement through the tip of the catheter enabled more accurate and real-time assist. Third, a novel balloon pump automatically selects the trigger source, arranges the timing of the IABP inflation/deflation, and detects the arrhythmias. Further development of IABP will bring safer and more reliable hemodynamic management in cardiac surgery.

Sensorless control for a sophisticated artificial myocardial contraction by using shape memory alloy fibre

The authors have been developing an artificial myocardium, which is capable of supporting natural contractile function from the outside of the ventricle. The system was originally designed by using sophisticated covalent shape memory alloy fibres, and the surface did not implicate blood compatibility. The purpose of our study on the development of artificial myocardium was to achieve the assistance of myocardial functional reproduction by the integrative small mechanical elements without sensors, so that the effective circulatory support could be accomplished. In this study, the authors fabricated the prototype artificial myocardial assist unit composed of the sophisticated shape memory alloy fibre (Biometal), the diameter of which was 100 microns, and examined the mechanical response by using pulse width modulation (PWM) control method in each unit. Prior to the evaluation of dynamic characteristics, the relationship between strain and electric resistance and also the initial response of each unit were obtained. The component for the PWM control was designed in order to regulate the myocardial contractile function, which consisted of an originally-designed RISC microcomputer with the input of displacement, and its output signal was controlled by pulse wave modulation method. As a result, the optimal PWM parameters were confirmed and the fibrous displacement was successfully regulated under the different heat transfer conditions simulating internal body temperature as well as bias tensile loading. Then it was indicated that this control theory might be applied for more sophisticated ventricular passive or active restraint by the artificial myocardium on physiological demand.

Acquired left ventricular-right atrial communication and severe aortic valve regurgitation caused by infective endocarditis

We report here on a surgical case of acquired left ventricular right atrial communication (LV-RA communication) and aortic regurgitation (AR) caused by infective endocarditis (IE). We successfully treated the patient with composite patches made from polytetrafluoroethylene (PTFE) and autologous pericardium. In general, LV-RA communication is a rare congenital cardiac anomaly (Gerbode-type shunt). However, acquired LV-RA communications secondary to IE are occasionally reported.When repairing an acquired condition due to IE, particular care should be taken to avoid recurrence, persistent infection and iatrogenic atrioventricular block.

[The use of 19 Fr silicone drains in chest surgery]

We evaluated a single 19 Fr Blake drain after chest surgery retrospectively. 50 patients underwent drainage of their pleural cavity using Blake drains. Blake drain was found to be effective in drainage of both air and fluid. In addition, this soft silicone drain seemed to improve the comfort of the patients. One single Blake drain is considered to be an option for chest drainage in most of general thoracic surgery.

[Cardiac surgery in patients with liver dysfunction; preoperative assessment, determinants, and consequences]

The population of patients with liver cirrhosis and congestive liver who are referred for cardiac operation is not large and definitive indications for surgical interventions remain unknown. We reviewed the literature on its clinical features and outcomes after cardiac surgery that would help cardiac surgeons to decide cardiac modality. According to our experiences, in cirrhotic patients, cardiac surgery can be performed safely in Child-Pugh class A and selected patients with class B. In addition, liver cirrhosis causes postoperative deterioration of liver function, especially when the indocyanine green (ICG)-R15 value exceeds 40%. Technetium-99m galactosyl human serum albumin liver scintigraphy is also useful for preoperative assessment. In patients with congestive liver, preoperative serum total bilirubin and technetium-99m galactosyl human serum albumin liver scintigraphy may become the determinant of indications. Careful patient selection and intensive perioperative care are required to improve the clinical outcome in patients with liver dysfunction undergoing cardiac surgery.

Acceleration of primary liver tumor growth rate in embolized hepatic lobe after portal vein embolization

BACKGROUND

Portal vein embolization (PVE) is now widely accepted as a useful preoperative procedure in selected patients undergoing extended hepatectomy. However, the effect of PVE on the growth of liver tumors has not been fully elucidated.

PURPOSE

To retrospectively evaluate the effects of PVE on the growth of liver tumors in the embolized lobes.

MATERIAL AND METHODS

Eight patients with a primary liver tumor, six hepatocellular carcinomas (HCC) and two cholangiocellular carcinomas (CCC), were studied. The growth rates of the tumors in the embolized lobes and non-embolized liver parenchyma were calculated using the computed tomography (CT) volume values at the time of tumor identification, and before and after PVE.

RESULT

The median tumor growth rate was 0.59 cm(3)/day (range 0.22-6.01 cm(3)/day) before PVE and 2.37 cm(3)/day (range 0.29-13.97 cm(3)/day) after PVE (P = 0.018). The tumor growth acceleration ratios ranged from 1.50 to 7.46 (median 2.65) in the six HCCs, and were 1.00 and 1.32 in the two CCCs. There was no apparent correlation between the tumor growth rate after PVE and the growth rate of non-embolized liver parenchyma (median 6.00 cm(3)/day, range 1.24-11.0 cm(3)/day).

CONCLUSION

Liver tumor growth in an embolized lobe accelerates after PVE, in patients with HCC.

Expression of immature and mature retinal cell markers in retinoblastoma

AIM

To clarify the expression of immature and mature retinal cell makers in retinoblastoma cells and to give insights into the cell origin of the retinoblastoma.

MATERIALS AND METHODS

Five samples from five eyes diagnosed with retinoblastomas were analysed by a standard immunohistochemistry using antibodies against Nestin and the hairy and enhancer of split mammalian homologue-1 (HES-1), both as markers for undifferentiated cells, and against Chx10, as a marker for both undifferentiated retinal cells and mature bipolar cells. Photoreceptor-specific nuclear receptor (PNR) was used as a postmitotic rod photoreceptor cell-specific marker, glial fibrillary acidic protein (GFAP) as a mature glia cell marker, and microtubule-associated protein (MAP) 2 as a mature neuronal cell marker.

RESULTS

Nestin was detected in what were possibly Müller cells, but not in the tumour stroma. HES-1 was not detected in the retinoblastoma tissue. Chx10 was detected in one of the five samples. In this one sample, Chx10 expression was confined in a minor portion of the retinoblastoma cells. PNR was not detected in the retinoblastoma tissue. Expression of GFAP was detected only in the stromal cells of the tumour, which presumably represents reactive stromal astrocytes. In contrast, in all the samples, MAP2 was expressed in most of the retinoblastoma cells.

CONCLUSIONS

The results of the current study support that retinoblastomas are derived from mature neural cells but do not originate from tumour stem cell(s).

The effect of interaction between hepatitis C virus and cigarette smoking on the risk of hepatocellular carcinoma

We evaluated the interaction between hepatitis C virus (HCV) and cigarette smoking on death from hepatocellular cancer in The Japan Collaborative Cohort Study. The odds ratio of death from HCC for smoking was 9.60 (1.50–61.35) and 1.71(0.58–5.08) among anti-HCV positive and negative individuals, respectively.

Coffee and risk of death from hepatocellular carcinoma in a large cohort study in Japan

We examined the relation between coffee drinking and hepatocellular carcinoma (HCC) mortality in the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC Study). In total, 110 688 cohort members (46 399 male and 64 289 female subjects) aged 40–79 years were grouped by coffee intake into three categories: one or more cups per day, less than one cup per day and non-coffee drinkers. Cox proportional hazards model by SAS was used to obtain hazard ratio of HCC mortality for each coffee consumption categories. The hazard ratios were adjusted for age, gender, educational status, history of diabetes and liver diseases, smoking habits and alcohol. The hazard ratio of death due to HCC for drinkers of one and more cups of coffee per day, compared with non-coffee drinkers, was 0.50 (95% confidence interval 0.31–0.79), and the ratio for drinkers of less than one cup per day was 0.83 (95% confidence interval 0.54–1.25). Our data confirmed an inverse association between coffee consumption and HCC mortality.

Improvement of portal hypertension and hepatic blood flow in cirrhotic rats by oestrogen

BACKGROUND

In this study, we investigated the effects of oestrogen on nitric oxide synthase activity and nitric oxide production using the cirrhotic rat liver.

MATERIAL AND METHODS

Cirrhosis was induced by dimethylnitrosamine. Estradiol valerate was subcutaneously injected twice at week 4 after dimethylnitrosamine treatment. Furthermore, subcutaneous injection of an oestrogen receptor antagonist, ICI-182.780, was performed 2 days before administration of estradiol valerate. Portal pressure and hepatic blood flow were measured. Nitric oxide synthase activity was assessed by l-citrulline generation. Sinusoidal endothelial cells were isolated from the cirrhotic rat liver and cultured. The cells were incubated with estradiol and/or ICI-182.780 for 24 h. Images for nitric oxide in sinusoidal endothelial cells were obtained using diaminofluorescein-2 diacetate.

RESULTS

Cirrhotic rats treated with estradiol valerate showed a significant decrease in portal pressure and a significant increase in hepatic blood flow compared with those of control cirrhosis rats. However, in cirrhotic rats treated with ICI-182.780, the reduction of portal pressure and elevation of hepatic blood flow were completely inhibited. In cirrhotic rats treated with estradiol valerate, nitric oxide synthase activity was increased compared with that in control cirrhotic rats. The fluorescent level of intracellular nitric oxide in estradiol-stimulated, cultured, sinusoidal endothelial cells was higher than that in nontreated sinusoidal endothelial cells.

CONCLUSIONS

The present study indicated that oestrogen plays an important role in the enhancement of nitric oxide production in sinusoidal endothelial cells of cirrhotic liver and reduces the portal pressure in cirrhotic rats.

Sustained effects of plasma norepinephrine levels on femoral-radial pressure gradient after cardiopulmonary bypass

In order to determine the influence of the sympathetic nervous system upon the femoral-radial artery pressure gradient after cardiopulmonary bypass (CPB), we examined plasma norepinephrine levels in 34 adult male patients undergoing coronary artery bypass grafting. Cardiovascular parameters, including systolic arterial pressure, mean arterial pressure, cardiac index (CI), systemic vascular resistance index (SVRI), pulmonary artery pressure (PAP), hemoglobin (Hb) and peak dP/dt of radial and femoral artery pressures were measured after sternotomy, and immediately after the discontinuation of CPB and 90 min after CPB. Plasma norepinephrine levels were measured after sternotomy, after aortic declamping and 90 min after CPB. The patients were divided into two groups. Group A consisted of 17 patients whose femoral minus radial systolic pressure difference was 15 mmHg or more at 90 min after CPB, while Group B consisted of 17 patients with the difference less than 15 mmHg. Group A patients had significantly longer time values in the duration of both CPB (Group A 175 +/- 10 min; Group B 115 +/- 12 min, P < 0.001) and aortic cross clamping (Group A 116 +/- 7 min, Group B 71 +/- 9 min, P < 0.001). Although there was no significant difference in Hb or PAP of 90 min after CPB in Groups A and B, the following values, listed in the order of A to B, were obtained; CI, 2.79 +/- 0.10 versus 3.46 +/- 0.16 l.min(-1).m(-2) (P < 0.01); mean radial artery pressure (MRP), 58.7 +/- 2.4 versus 65.1 +/- 1.8 mmHg (P < 0.05); peak dP/dt of radial artery pressure, 568 +/- 64 versus 1026 +/- 61 mmHg.sec(-1) (P < 0.001); and plasma norepinephrine concentration, 1.81 +/- 0.25 versus 0.98 +/- 0.10 ng.ml(-1) (P < 0.01), which were statistically significant. The higher femoral-radial artery pressure gradient after CPB was observed in patients with both a longer CPB time and a higher plasma norepinephrine concentration. These results suggest that a marked constriction of peripheral arteries might have produced a damped transmission of the pressure pulse to the radial artery.

Bilateral video-assisted thoracoscopic surgery in the supine position for primary spontaneous pneumothorax

On the basis of the bilateral nature of bullous lesions of the lung, the authors have performed single-stage bilateral video-assisted thoracoscopic surgery (VATS) in the supine position for primary spontaneous pneumothorax in five patients since October 1999. All five patients were males with a mean age of 23 years (range 19 to 29 years). The presenting pneumothorax was ipsilateral (right-sided) in four patients and simultaneous bilateral in the one remaining patient. Apart from the one case of simultaneous bilateral spontaneous pneumothorax (SBSP), all patients had a history of at least one pneumothorax episode requiring tube thoracotomy. Bilateral bullae were confirmed in all patients on preoperative chest computed tomography (CT). Bilateral bullectomy was performed by endo-stapler with no difficulties. Mean operating time was 111 minutes (range 85 to 140 minutes). All patients were returned to the surgical ward in good condition from the operating room immediately after extubation. No complications were observed, and duration of postoperative hospital stay was two to four days. All patients were alive without recurrence of pneumothorax after a mean follow-up period of 25 months (range, 9 to 43 months). Single-stage bilateral VATS in the supine position has shown itself to be an excellent approach for the treatment of bilateral bullous lesions, combining both efficacy and low morbidity.

Supraclavicular Approach Without Thoracotomy for Posterior Mediastinal Tumor

Using a right-sided supraclavicular approach, we operated on a 15-year-old girl with a posterior mediastinal neurogenic tumor and von Recklinghausen's disease. The encapsulated 95 x 65 x 40 mm neurofibroma was removed safely and completely without thoracotomy. No peripheral neurologic defect such as Horner's syndrome, paralysis of accessory nerve, or palsy of the right upper extremity was observed after operation. The postoperative course was uneventful and the patient was discharged on the third postoperative day with no symptoms. Today, various adaptations of video-assisted thoracic surgery are frequently utilized for many lesions. However, more direct, safer, and less invasive approaches should be selected based on local anatomy, such as the supraclavicular approach without thoracotomy that we utilized.

The Figure-L Unilateral Mini-Sternotomy for Anterior Mediastinal Tumor

We performed a figure-L unilateral mini-sternotomy for anterior mediastinal tumor resection in ten patients. Pathological diagnosis among the ten included six thymomas, three mature teratomas including one with a seminoma component, and one thymic cyst. Mean tumor length was 7 x 5 x 4 cm. The required skin incision was 8 cm in mean length. The third intercostal space was transected in six cases, the fourth intercostal space in four cases. Bilateral internal thoracic arteries were preserved in all cases. All tumors were completely resected without complications during the procedure. Mean operating time was 106 minutes (range 85 to 120 minutes). Postoperative hospital stay ranged from three to seven days without any complications. All patients were alive at the end of a mean follow-up period of 39 months (range 3 to 60 months). The figure-L unilateral mini-sternotomy is considered an effective and useful minimally invasive approach for anterior mediastinal tumors.

Mechanical stretch induces TGF-beta synthesis in hepatic stellate cells

BACKGROUND

It is known that mechanical stress induces extracellular matrix via transforming growth factor-beta (TGF-beta) synthesis in vascular smooth muscle cells. Activated hepatic stellate cells (HSCs) are an important source of TGF-beta in the liver. However, it remains unclear whether mechanical stress induces TGF-beta in HSCs. The Rho small GTP-binding protein (Rho) has recently emerged as an important regulator of actin and cytoskeleton. We examined whether TGF-beta is expressed in stretched HSCs and whether Rho is involved in stretch-induced TGF-beta synthesis.

MATERIALS AND METHODS

A cultured human HSC cell line, LI90, was used for this study. Hepatic stellate cells were cyclically stretched using the Flexercell(R) strain unit. Concentration of TGF-beta in the conditioned medium was estimated by a bioassay using mink lung epithelial cells transfected with a plasminogen activator inhibitor-1 promoter-luciferase construct. Transforming growth factor-beta mRNA expression of HSCs was estimated by a reverse-transcription polymerase chain reaction. Replication-defective adenoviral vectors expressing a dominant negative type of Rho was utilized to suppress its effect on HSCs.

RESULTS

Transforming growth factor-beta concentration of the conditioned media of stretched HSCs showed time-dependent increases as compared to nonstretched HSCs from 2 h to 24 h. Transforming growth factor-beta mRNA expression in stretched HSCs was increased compared with that in nonstretched HSCs. Transfection of dominant negative Rho inhibited the stretch-induced TGF-beta synthesis.

CONCLUSIONS

Mechanical stretch enhanced TGF-beta expression on mRNA and protein level in HSCs. Rho was closely related to stretch-induced TGF-beta synthesis in HSCs.

Placement of the Dumon Stent Using a Flexible Bronchofiberscope via Tracheostomy

In this paper, we report on a new technique of Dumon stent placement using a flexible bronchofiberscope. This procedure was used to insert Dumon stents in two bronchial obstruction and two bronchofistula cases. The stenting technique described here can be used through either a tracheostoma or the oral cavity; it presents a very straightforward and safe procedure that does not require the use of a rigid bronchoscope.

A single-stage video-assisted thoracoscopic surgery procedure for simultaneous bilateral spontaneous pneumothorax in a supine position

We report on the case of a 23-year-old man with simultaneous bilateral spontaneous pneumothorax (SBSP), treated with bilateral video-assisted thoracoscopic surgery (VATS) in a supine position. SBSP is a very rare condition that can be life-threatening when therapeutic techniques fail. We performed a unique operative procedure for SBSP using one-stage bilateral VATS in a supine position. This procedure is less invasive, more effective, and safer for the treatment of SBSP.

[Aortic root replacement using cryopreserved allograft for an infected aorta patient associated with mediastinitis]

We herein report a case of aortic root replacement using cryopreserved allograft. A 52-year-old man received aortic valve replacement using a mechanical prosthesis for aortic stenosis. He was complicated by postoperative methicillin-resistant staphylococcus aureus mediastinitis involving the ascending aorta. Surgical therapy including debridement, omental transposition, patch closure using pericardium had not achieved satisfied result. Aortic root replacement using cryopreserved allograft was mandatory for refractory aortic infection. He had an uneventful postoperative course. The cryopreserved allograft was effective for a patient with refractory aortic root infection due to postoperative mediastinitis.

Primary chylopericardium treated with video-assisted thoracoscopic surgery

Here, we report on a 30-year-old female with primary chylopericardium who successfully underwent thoracic duct clipping and partial pericardiectomy using video-assisted thoracoscopic surgery (VATS). Recently, a few cases of this disease have been treated utilizing VATS. This is a fully detailed description of the treatment of primary chylopericardium including a description of intraoperative findings and photographs obtained during the course of VATS.

A new combined surgical procedure for severe descending necrotizing mediastinitis with bilateral empyema

In this report, we will describe the treatment of a 38-year-old man with severe descending necrotizing mediastinitis (DNM) with bilateral empyema. DNM is a rare disease with a high mortality rate, and when accompanied by bilateral empyema, this is particularly serious and potentially fatal. To improve the prognosis of such patients, the establishment of an adequate surgical procedure for satisfactory debridement and drainage is essential. This is the first report on a new combined surgical procedure consisting of right standard posterolateral thoracotomy and left video-assisted thoracoscopic surgery (VATS) for severe DNM with bilateral empyema.

[Combined surgery for cardiovascular disease and general thoracic lesions]

Surgical management of patients with concomitant critical cardiovascular disease and resectable general thoracic lesions is controversial. During a 16-year period (1985 to 2001), 15 patients underwent combined cardiovascular and general thoracic operations, of the 2,459 patients who underwent a cardiovascular operation requiring cardiopulmonary bypass at our institution. Patients had cardiovascular symptoms only and the general thoracic lesions were incidentally found by preoperative chest roentgenograms and/or computed tomography. Because of the cardiovascular disease, a pathological diagnosis was precluded before surgery. All except one descending thoracic aortic operation underwent concurrent pulmonary resection after neutralization of protamine following cardiovascular surgery requiring extracorporeal circulation. Lung pathology consisted of pulmonary bullae (n = 7), primary lung cancer (n = 4), benign lung tumor (n = 2), metastatic lung cancer (n = 1), and thymic cyst (n = 1). The pulmonary operations include bullectomy (n = 7), wedge resection (n = 6), lobectomy (n = 3), and removal of a thymic cyst (n = 1) including 2 staged procedures. The final diagnoses in 4 lung cancer cases were T1. N0M0, stage IA (n = 3) and T2N2M0, stage IIIA (n = 1). All malignancies including metastatic lung cancer, were able to be completely resected. The mean intraoperative bleeding volume for the cases was 997 +/- 221 ml, while mean duration of surgery was 382 +/- 31 minutes. Except for 2 cases required long term ventilatory support, the mean durations of tracheal intubation and ICU stay were 2.2 +/- 0.2 and 3.8 +/- 1.0 days respectively. Except for 1 surgical death, mean survival duration and 5-year survival rate were 59.7 +/- 12.5 (5-177) months and 66.3% respectively. These findings suggest that combined pulmonary resection with cardiovascular surgery is safe and offers a favorable prognosis to a selected group of patients.

Antiplatelet therapy for a pregnant woman with a mechanical aortic valve: report of a case

A 24-year-old woman, who had undergone an aortic valve replacement with a 21-mm St. Jude Medical mechanical aortic valve, wished to have a child. She visited our department because she was aware of the risks associated with pregnancy while undergoing anticoagulant therapy using warfarin potassium. The patient opted to undergo the recommended alternative method involving the use of antiplatelet agents (dipyridamole, ticlopidine, and aspirin) in place of warfarin potassium. Antiplatelet agents were administered while regularly monitoring the platelet aggregability along with the coagulation and fibrinolytic activity. At the 36th week of gestation, antiplatelet agents were discontinued and instead were followed by continuous heparin infusion. A healthy baby was delivered by cesarean section without any complications at the 38th week. Antithrombotic therapy using antiplatelet agents appears to be an effective option for preventing serious problems for pregnant women with a mechanical heart valve.

Dynamic expression and essential functions of Hes7 in somite segmentation

The basic helix-loop-helix (bHLH) gene Hes7, a putative Notch effector, encodes a transcriptional repressor. Here, we found that Hes7 expression oscillates in 2-h cycles in the presomitic mesoderm (PSM). In Hes7-null mice, somites are not properly segmented and their anterior-posterior polarity is disrupted. As a result, the somite derivatives such as vertebrae and ribs are severely disorganized. Although expression of Notch and its ligands is not affected significantly, the oscillator and Notch modulator lunatic fringe is expressed continuously throughout the mutant PSM. These results indicate that Hes7 controls the cyclic expression of lunatic fringe and is essential for coordinated somite segmentation.