Latent Dirichlet allocation topic modeling of free-text responses exploring the negative impact of the early COVID-19 pandemic on research in nursing

AIM

To derive latent topics from free-text responses on the negative impact of the pandemic on research activities and determine similarities and differences in the resulting themes between academic-based and clinical-based researchers.

METHODS

We performed a secondary analysis of free-text responses from a cross-sectional online survey conducted by the Japan Academy of Nursing Science of its members in early 2020. The participants were categorized into two groups by workplace (academic-based and clinical-based researchers). Latent Dirichlet allocation (LDA) topic modeling was used to extract latent topics statistically and list important keywords/text associated with the topics. After organizing similar topics by principal component analysis (PCA), we finally derived topic-associated themes by reading the keywords/texts and determining the similarity and differences of the themes between the two groups.

RESULTS

A total of 201 respondents (163 academic-based and 38 clinical-based researchers) provided free-text responses. LDA identified eight and three latent topics for the academic-based and clinical-based researchers, respectively. While PCA re-grouped the eight topics derived from the former group into four themes, no merging of the topics from the latter group was performed resulting in three themes. The only theme common to the two groups was "barriers to conducting research," with the remaining themes differing between the groups.

CONCLUSIONS

Using LDA topic modeling with PCA, we identified similarities and differences in the themes described in free-text responses about the negative impact of the pandemic between academic-based and clinical-based researchers. Measures to mitigate the negative impact of pandemics on nursing research may need to be tailored separately.

A neck-preserving short stem better reconstructs the centre of rotation than straight stems: a computed tomography-based cadaver study

INTRODUCTION

Short femoral hip stems with a metaphyseal anchoring concept have been designed to treat younger patients with good bone quality. The aim of this study was to reconstruct the centre of rotation and soft tissue balancing and preserve bone in the long-term perspective.

MATERIALS AND METHODS

Eighteen human femurs were randomised into three groups: (1) metaphyseal anchoring short stem, (2) shortened straight stem, (3) straight stem). Prior to the implantation of the hip stems, a computed tomography (CT) of the bones was performed and the femoral ante-torsion and ante-tilt was measured and compared to the results of the post-implantation CT. This could be calculated based on the 3D coordinates taken from the pre- and post-op CT scans, which were transformed into the same coordinate systems.

RESULTS

The mean preoperative caput-collum-diaphyseal (CCD) angle for the three groups was 126.87° ± 3.50° (Group 3: 129.64° ± 3.53°, Group 1: 123.76° ± 5.56°, Group 2: 127.53° ± 1.42°) and was consistent with published reports. The postoperative CCD angles with 126.85° ± 3.43° were within a very good reconstruction range for all three groups. The anterior offset comparison among these three groups showed significant difference in reconstruction. The smallest difference between the anatomical (preoperative) and postoperative condition was seen in Group 1 (1.47° ± 0.60°), followed by Group 2 (3.60° ± 0.23°) and Group 3 (8.00° ± 0.70°) groups. The horizontal offset showed no significant difference among the groups and was within the window of ± 5 mm.

CONCLUSION

In this cadaver study, we found that the metaphyseal anchoring, partially neck-preserving short hip stem best reconstructs the ante-torsion and the ante-tilt of the femoral neck. Therefore, it can be a useful stem in younger or active middle-aged patients.

The factors related to recovery time of diaper dermatitis in infants: A prospective observational study

AIM

Prolonged diaper dermatitis may increase the risk of atopic dermatitis or infections. This prospective observational study aimed to investigate the prevalence, symptoms, areas, and recovery time of diaper dermatitis in infants aged 1 month and identify the factors related to recovery time.

METHODS

Diaper dermatitis was defined as the presence of erythema, papules, dryness, erosion, or ulceration in the diapered area. Recovery time was days between infant's 1-month medical check-up and disappearance of symptoms. Survival analysis was performed using the Kaplan-Meier method, and the log-rank test was used to identify the factors related to recovery time.

RESULTS

Among 113 infants, 66 (58.4%) had diaper dermatitis, with erythema at the perianal area being the most common symptom. The median recovery time was 10 days. Four infants (6.1%) had diaper dermatitis for >5 weeks. Severity was not related to recovery time.

CONCLUSIONS

A frequency of diaper changing of ≤10 times per day was a risk factor for recovery time. Our data showed recovery in approximately 10 days, regardless of severity at study enrollment. Health care professionals could inform parents of recovery time and recommended diaper changing frequency.

Propensity-matched comparisons of factors negatively affecting research activities during the COVID-19 pandemic between nursing researchers working in academic and clinical settings in Japan

Aim

To determine the factors associated with reduced research activities during the COVID‐19 pandemic in 2020 by comparing nursing researchers working in academic and clinical settings.

Methods

This was a secondary analysis of data collected by the Japan Academy of Nursing Sciences, which conducted a cross‐sectional online survey when the pandemic began. We included respondents who worked in either academic or clinical settings and responded that the pandemic negatively affected their research activities. First, we computed a propensity score (PS) using a logistic regression model. Then we performed a one‐to‐one ratio matching between the groups based on the PS to control imbalances between the groups. We identified the factors negatively affecting research activities and who to consult about research concerns by comparing the groups using Chi‐square or Fisher's exact tests.

Results

There were 1,532 participants, with a response rate of 16.1%. After PS matching, 214 participants (107 for each group) were included. We identified three significant factors associated with reduced research activities: (i) time required for learning new information and communication technology (ICT) skills; (ii) time required for supporting colleagues with ICT issues; and (iii) time required for preparing and evaluating teaching materials. Approximately 20% of our participants in both settings had nobody to consult regarding research concerns.

Conclusion

We found that the time spent on ICT‐related issues negatively affected the research activities of nursing researchers when the pandemic began in Japan. In such an emergency, nursing researchers needed an opportunity to share their difficulties as a part of a support service.

Dissemination of atopic dermatitis and food allergy information to pregnant women in an online childbirth preparation class

Background

Evidence-based allergy prevention strategies have been reported, but strategies for dissemination have not been evaluated. Improving health literacy and awareness of allergies in pregnant mothers is 1 example of dissemination and implementation science that could help prevent allergic diseases and promote early detection of allergic diseases in children.

Objective

We evaluated the usefulness of an online childbirth preparation class about prevention and early detection of allergic diseases in offspring.

Methods

From January 2021 to August 2021, an online allergy class for pregnant mothers was provided at the hospital in Tokyo. We conducted an online survey about allergy topics before and after the online childbirth preparation class.

Results

A total of 106 pregnant women attended the online allergy class, and 92 (86.8%) responded to the online survey. Of the respondents, 90 (97.8%) were worried about the development of allergies in their children. The topic that attracted the most attention in the lecture was the prevention of atopic dermatitis by means of skin care. The percentages of correct responses regarding allergy prevention strategies increased after the class. All mothers believed that the class was useful, the information should be disseminated to the public, and the practices should be implemented.

Conclusion

In online childbirth preparation classes, information about allergy based on dissemination and implementation science could strengthen allergy literacy among pregnant women.

Certified Reference Material for Analytical Quality Assurance of Minor and Trace Elements in Food and Related Matrixes Based on a Typical Japanese Diet: Interlaboratory Study

A Certified Reference Material (CRM) was prepared at the National Institute for Environmental Studies (NIES), Japan, in collaboration with the National Institute of Radiological Sciences (NIRS), Japan, for the analytical quality assurance of minor and trace elements in food and related matrixes. The starting material for the CRM was all food served in 29 households in Japan over two 3-day periods in 1997–1998, and thus the CRM represented a typical Japanese diet. All foods (meals, snacks, and beverages) were homogenized, freeze-dried, pulverized, blended, dispensed into 1100 bottles, and sterilized. The within- and between-bottle homogeneity of the prepared CRM was satisfactory for most of the elements. The concentrations of 14 elements (Na, Mg, K, Ca, Mn, Cu, Zn, As, Se, Sr, Cd, Sn, Ba, and U) were certified based on a collaborative analysis involving NIES, NIRS, and 20 other laboratories. Reference values were given for the concentrations of 12 additional elements (P, Cl, Fe, Co, Ni, Br, Rb, Mo, I, Cs, Pb, and Th). The elements certified and those given reference values include minerals, essential trace elements, contaminant elements, and long-lived radionuclides. Thus, this CRM is of practical value in the quality assurance of element analysis of foods and diets in nutritional, environmental, and radiological research.

P2540Sex-specific differences in the clinical presentation, surgical complications, and course of chronic thromboembolic pulmonary hypertension

Background

Women are more susceptible to develop several forms of pulmonary hypertension, but they may have better survival rates than men. Sparse data are available concerning sex-specific differences in chronic thromboembolic pulmonary hypertension (CTEPH).

Purpose and methods

We investigated sex-specific differences in the clinical presentation of CTEPH, functional parameters, exposure to pulmonary endarterectomy (PEA), and survival.

Results

Women constituted half of the study population (N=679 treatment-naïve patients from the European CTEPH registry) and were characterized by a lower prevalence of some cardiovascular risk factors (e.g. prior acute coronary syndrome, smoking habit, chronic obstructive pulmonary disease), but more prevalent obesity, cancer, and thyroid diseases. Median age was 62 (IQR 50–73) years in women and 63 (IQR 53–70) in men. Women underwent PEA less often than men (54% vs 65%; Figure 1, Panel A) and were exposed to fewer additional cardiac procedures, notably coronary artery bypass graft surgery (0.5% vs. 9.5%). The prevalence of specific reasons for not being operated, including the patient's refusal and the proportion of proximal vs. distal lesions, did not differ between sexes. A total of 57 (17.0%) deaths in women and 70 (20.7%) in men were recorded over long-term follow-up. Female sex was positively associated with long-term survival (adjusted Hazard Ratio 0.66; 95% Confidence Interval 0.46–0.94). Short-term mortality was identical in the two groups (Figure 1, Panel B).

Conclusions

Women with CTEPH had a lower prevalence of cardiovascular risk factors and underwent PEA less frequently than men, who, in turn, were more often exposed to additional major cardiac surgery procedures. Women had more favorable long-term survival.

Acknowledgement/Funding

The CTEPH registry is supported by a research grant from Actelion Pharmaceuticals Ltd.

Molecular alterations of newly formed mandibular bone caused by zoledronate

Bone quality is defined by structural and material characteristics. Most studies on the mandible have focused on the analysis of structural characteristics, with insufficient investigation of material characteristics. This study tested whether zoledronate affects the material characteristics of newly formed mandibular bone. Thirty-six female Wistar rats were assigned to three groups: sham-ovariectomized rats (SHAM, n=12), ovariectomized rats (OVX, n=12), and ovariectomized rats treated with zoledronate (ZOL, n=12). The left side of the mandibular ramus of all rats was drilled bicortically. Twenty-eight days after surgery, all surviving rats were euthanized and all mandibles were removed. Raman microspectroscopy was performed, and five spectra per specimen of newly formed mandibular bone were analysed. Compared with OVX rats, the mineral/matrix ratio in ZOL rats was significantly increased (5.43±1.88 vs. 7.86±2.05), while crystallinity (0.055±0.002 vs. 0.050±0.002), relative proteoglycan content (0.43±0.10 vs. 0.31±0.05), and collagen structural integrity (1.16±0.21 vs. 0.72±0.06) were significantly decreased. These changes in material characteristics may explain why rats that received zoledronate exhibited peculiar biological phenomena such as bisphosphonate-related osteonecrosis of the jaw.

A new evaluation of masticatory ability in patients with dysphagia: The Saku-Saku Test

OBJECTIVE

In the elderly and patients with dysphagia, masticatory problems often cause aspiration or choking. Although simple methods to predict aspiration and silent aspiration exist, methods for evaluating the masticatory function of patients with dysphagia are lacking. Accordingly, we developed a simple test to assess the chewing and swallowing ability of patients with dysphagia.

METHODS

One hundred and five patients with dysphagia were included. We used the Saku-Saku Test (SST), in which patients were asked to eat a rice cracker, and evaluated the quality of mandibular rotation during mastication. We studied the participants' ability to grind, aggregate, and swallow using videoendoscopic evaluation (VE) and investigated its association with mandibular rotation.

RESULTS

The SST showed good reliability between two examiners, with a kappa coefficient of 0.80. 92.4% of the patients ate the rice cracker without aspiration. The SST showed a high sensitivity of 73.3% and specificity of 93.3% for the degree of grinding. The degree of food bolus aggregation had a sensitivity of 45.0% and specificity of 90.6%, and aspiration had a sensitivity of 25.0% and specificity of 84.5%, both of which showed high specificity.

CONCLUSIONS

The results of this study suggested that the SST might be simple and useful for identifying patients with dysphagia who are able to masticate, even if they do not eat foods that need chewing and could be used before starting these patients on foods that need chewing.

Fine Needle Aspiration Cytology for Soft Tissue Tumours of the Hand

The purpose of this study was to evaluate the usefulness of fine needle aspiration cytology for the preoperative diagnosis of soft tissue tumours of the hand. Fine needle aspiration cytology was performed on 93 soft tissue tumours of the hand which were classified as malignant, benign or unclassified based on cytological findings. We also attempted to make specific diagnosis by cytology. The cytological diagnosis was then compared with the postoperative histopathological diagnosis. The cytological differentiation between benign and malignant tumours showed neither false-positive nor false-negative results. Of the 47 lesions with sufficient material for cytology and that were postoperatively diagnosed histologically, 35 (including one recurrent lesion) were correctly diagnosed by fine needle aspiration cytology. No complications were encountered. Fine needle aspiration cytology has a high degree of diagnostic accuracy and safety for soft tissue tumours of the hand.

Pleomorphic lobular carcinoma of the breast: a comparison of cytopathological features with other lobular carcinoma variants

OBJECTIVE

Pleomorphic lobular carcinoma (PLC) is a subtype of breast cancer with unique morphological features, but it remains controversial whether PLC should be considered an independent disease entity. The aim of this study was to illustrate cytopathological characteristics of PLC in comparison with other lobular carcinoma variants.

METHODS

We investigated clinicopathological features of PLC (n = 11) compared with those of other variants of invasive lobular carcinoma (ILC, non-PLC) (n = 32). Histological variants of the non-PLC group consisted of classic (n = 25), solid (n = 2), alveolar (n = 1) and a tubulolobular type (n = 4). A review of cytological reports and fine needle aspiration (FNA) smear samples was performed for the PLC (n = 9) and non-PLC (n = 27) groups.

RESULTS

Patients with PLC were older, and had a higher nuclear grade and a higher incidence of axillary lymph node metastasis and triple negative phenotype than non-PLC patients (P = 0.007, P < 0.001, P = 0.02 and P < 0.001, respectively). Cytological findings in PLC included medium- to large-sized nuclei, prominent nucleoli, a moderate-to-severe degree of pleomorphism, apocrine change and background necrosis, none of which were evident in the smears of the non-PLC group (P < 0.001, P = 0.002, P < 0.001, P < 0.001, and P = 0.03, respectively). Despite these differences, patients with PLC and non-PLC showed similar clinical outcomes in our follow-up period.

CONCLUSIONS

Based on our results, a cytological diagnosis of PLC should be proposed if there are moderate- to large-sized nuclei, prominent nucleoli, a moderate-to severe degree of nuclear pleomorphism, apocrine change and necrosis in the background in FNA biopsy samples.

Mucinous carcinoma of the breast: a comparative study on cytohistological findings associated with neuroendocrine differentiation

OBJECTIVE

Mucinous carcinoma (MCA) may show neuroendocrine differentiation (ND), but the cytological features characteristic of ND remains elusive. We compared fine needle aspiration (FNA) findings of MCA between cases with high and low degrees of ND.

METHODS

Histological sections of 37 MCA cases were immunohistochemically evaluated for expression of chromogranin A and synaptophysin, and were graded as 0 to 3+ degrees of ND. They were divided into low ND (grade 0 and 1+) and high ND (grade 2+ and 3+) groups. Pre-operative FNA samples of each group were assessed for cytological features.

RESULTS

The mean age of the high ND group (n = 18) was higher than the low ND group (n = 19, P = 0.01). In FNA samples of the high ND group, 17 cases showed moderate to severe degrees of discohesiveness, but low ND cases mainly showed no or only mild discohesiveness (P < 0.001). Nine of the low ND cases displayed overlapped, cohesive cell clusters, whereas, in the high ND cases, the cells were arranged in a loose, flat and monolayered pattern (P = 0.045). Fourteen of the high ND cases had round nuclei, but oval nuclei were predominant in the low ND cases (P = 0.027). The nuclei were eccentrically located in 12 of the high ND cases but were centrally located in 14 of the low ND cases (P = 0.01).

CONCLUSIONS

Mucinous carcinoma with high ND may be diagnosed by the presence of discohesiveness, a flat, monolayered pattern, and round or eccentrically located nuclei. Features of ND in carcinomas in other organs, such as intracytoplasmic granules and coarse chromatin, may not be reliable cytological features of ND in MCA.

Infant feeding practices and breastfeeding duration in Japan: A review

The Japanese health system places great emphasis on healthy development. However, the prevalence of Exclusive Breastfeeding at one month postpartum between 1980 and 2005 has remained unchanged, fluctuating between 42% and 49%. At the same time, the Any Breastfeeding prevalence has gradually increased from about 80% to 95%. In 2010, the latest national breastfeeding report showed that 'exclusive' and 'any' breastfeeding rates have improved. However, as the World Health Organization (WHO) definition of breastfeeding practices was not used in this study or in other national surveys, it is difficult to interpret these latest results. While the Japanese government has launched several promotion projects, there have been few studies and reviews of risk factors that influence breastfeeding duration. The objectives of this review were to summarise the factors that have influenced the duration of breastfeeding in Japan to provide information relevant to breastfeeding promotion programs. A search of electronic databases in Japanese and English was undertaken up to 2011. The inclusion criteria for this review were studies that focused on infant feeding practices and targeted Japanese mothers, fathers, or health professionals, but excluded mothers' friends and peer groups. In total, 12 articles were selected for the final analysis. Smoking status, low birth weight of infants and maternal perceptions of insufficient breast milk supply were negative influences on breastfeeding duration, while support from husbands/partners is associated with continued breastfeeding. Some factors that have been found to be associated with breastfeeding in other countries, including maternal age, family income, maternal educational levels, and living with grandparents of infants have not been confirmed in Japan. While the national breastfeeding rates were higher than other countries of similar health status, inconsistent knowledge of breastfeeding benefits and inappropriate hospital practices remain in Japan may be associated with increased the use of infant formula and reduced breastfeeding duration. Most of the studies reviewed were cross-sectional in design, with only a limited number of cohort studies. Also many published studies used small sample sizes. Cohort studies of infant feeding practices with larger sample sizes are required to monitor trends in rates and risk factors for breastfeeding outcomes.

P1-12-19: Phase I Study of Single Agent Trastuzumab Emtansine in Japanese Patients with Human Epidermal Growth Factor Receptor2 (HER2)-Positive Metastatic Breast Cancer (JO22591)

Background Trastuzumab emtansine (T-DM1), first-in-class anti-HER2 antibody-drug conjugate (ADC) is under development for the treatment of HER2−postive recurrent locally advanced or metastatic breast cancer (MBC). T-DM1 is composed of: trastuzumab; DM1, an inhibitor of tubulin polymerization derived from maytansine; and the stable MCC linker that conjugates DM1 and trastuzumab. T-DM1 has been evaluated at multiple dose levels in a phase I trial (TDM3569g): every 3 weeks (q3w) (0.3−1.8 mg/kg) and weekly (1.2−2.9 mg/kg), and in two subsequent phase II trials (TDM4258g and TDM4374g) for patients with heavily pretreated HER2−positive MBC. T-DM1 monotherapy (3.6 mg/kg q3w) has demonstrated robust clinical efficacy in these two phase II clinical studies. Dose escalation data from the TDM3569g provided the basis for this phase I study (JO22591) study, to investigate the maximal tolerated dose (MTD) in Japanese patients.

Methods This Japanese Phase I study was a single-arm, dose-escalation study in patients with HER2−positive MBC who had received prior therapies that included trastuzumab. The objective of the study was to determine the MTD of T-DM1 during Cycle 1, using the continual reassessment method, among three dose cohorts when administered as a single agent and to investigate safety, tolerability and pharmacokinetics of T-DM1 in patients with HER2−positive MBC. Eligibility criteria were standard for this type of study. T-DM1 was administered every 3 weeks at a dose level of 1.8 mg/kg, 2.4 mg/kg or 3.6 mg/kg. Outcomes were assessed by standard solid-tumor phase I methods. Adverse events were reported using CTCAE version 3.0, and tumor response was assessed according to RECIST version 1.0.

Results Ten patients were recruited: (1.8 mg/kg [n=1], 2.4 mg/kg [n=4], or 3.6 mg/kg [n=5]. One patient in the 2.4 mg/kg group experienced DLTs (Grade 3 AST increase and ALT increase). No other adverse events corresponding to a DLT were observed in any other patients during the DLT observation period. As a result, the MTD in Japanese MBC patients was determined to be 3.6 mg/kg q3w.

The most frequently reported adverse events, regardless of whether they were related to the study drug, were nausea, fatigue, arthralgia and pyrexia. The main changes in laboratory test values recorded were platelet count decrease, AST increase and ALT increase. Efficacy was preliminarily assessed with tumor responses, a partial response was observed in two patients. Most of the AEs were mild and manageable. There were no marked differences in any pharmacokinetic parameters for T-DM1, DM1 or total trastuzumab following administration of T-DM1 between the JO22591 study and the two Western studies (TDM3569g and TDM4258g), and no data obtained suggested any ethnic differences.

Conclusions T-DM1 monotherapy (3.6 mg/kg every 3 weeks) was well-tolerated in Japanese patients. PK and safety in Japanese patients were comparable to PK and safety in the Western population. These results support further clinical studies with T-DM1 in Japanese patients.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-12-19.

Comparison of actual tidal volume in neonatal lung model volume control ventilation using three ventilators

In neonates, small changes in tidal volumes (V(T)) may lead to complications. Previous studies have shown a significant difference between ventilator-measured tidal volume and tidal volume delivered (actual V(T)). We evaluated the accuracy of three different ventilators to deliver small V(T) during volume-controlled ventilation. We tested Servo 300, 840 ventilator and Evita 4 Neoflow ventilators with lung models simulating normal and injured neonatal lung compliance models. Gas volume delivered from the ventilator into the test circuit (V(TV)) and actual V(T) to the test lung were measured using Ventrak respiration monitors at set V(T) (30 ml). The gas volume increase of the breathing circuit was then calculated. Tidal volumes of the SV300 and PB840 in both lung models were similar to the set V(T) and the actual tidal volumes in the injured model (20.7 ml and 19.8 ml, respectively) were significantly less than that in the normal model (27.4 ml and 23.4 ml). PB840 with circuit compliance compensation could not improve the actual V(T). V(TV) of the EV4N in the normal and the injured models (37.8 ml and 46.6 ml) were markedly increased compared with set V(T), and actual V(T) were similar to set V(T) in the normal and injured model (30.2 ml and 31.9 ml, respectively). EV4N measuring V(T) close to the lung could match actual V(T) to almost the same value as the set V(T) however the gas volume of the breathing circuit was increased. If an accurate value for the patient's actual V(T) is needed, this V(T) must be measured by a sensor located between the Y-piece and the tracheal tube.

Is routine chemical thromboprophylaxis after total hip replacement really necessary in a Japanese population?

Prophylaxis against venous thromboembolism after elective total hip replacement is routinely recommended. Our preference has been to use mechanical prophylaxis without anticoagulant drugs. A randomised controlled trial was performed to evaluate whether the incidence of post-operative venous thromboembolism was reduced by using pharmacological anticoagulation with either fondaparinux or enoxaparin in addition to our prophylactic mechanical regimen. A total of 255 Japanese patients who underwent primary unilateral cementless total hip replacement were randomly assigned to one of three postoperative regimens, namely injection of placebo (saline), fondaparinux or enoxaparin. There were 85 patients in each group. All also received the same mechanical prophylaxis during and after the operation, regardless of their assigned group. The primary measurement of efficacy was the presence of a venous thromboembolic event by day 11, defined as deep-vein thrombosis detected by ultrasonography, documented symptomatic deep-vein thrombosis or documented symptomatic pulmonary embolism. The duration of follow-up was 12 weeks.

The rate of venous thromboembolism was 7.2% with the placebo, 7.1% with fondaparinux and 6.0% with enoxaparin (p = 0.95 for the comparison of all three groups). Our study confirmed the effectiveness and safety of mechanical thromboprophylaxis without the use of anticoagulant drugs after total hip replacement in Japanese patients.

Suppressive effects of 1,4-dihydroxy-2-naphthoic acid administration on bone resorption

SUMMARY

The main component of the metabolic by-products of fermentation by Propionibacterium freudenreichii ET-3 is 1,4-dihydroxy-2-naphthoic acid (DHNA), which has a naphthoquinone skeleton, as in vitamin K2. This study showed that DHNA improved bone mass reduction with osteoporosis model mice caused by FK506.

INTRODUCTION

Growth of the intestinal bacterium Lactobacillus bifidus is specifically facilitated by DHNA. The present study used osteoporosis model mice to investigate the effects of DHNA on bone remodeling.

METHODS

FK506, an immunosuppressant, was used to prepare osteoporosis model mice. Thirty mice were divided into three groups: FK group, FK+DHNA group, and control group. In the FK group, FK506 was administered to induce bone mass reduction. In the FK-DHNA group, FK506 and DHNA were administered concurrently to observe improvements in bone mass reduction. To ascertain systemic and local effects of DHNA, we investigated systemic pathological changes in colon, kidney function and cytokine dynamics, and morphological and organic changes in bone and osteoclast dynamics as assessed by culture experiments.

RESULTS

Compared to the FK group without DHNA, colon damage and kidney dysfunction were milder for FK+DHNA group, and production of inflammatory cytokines (interleukin (IL)-1beta, IL-6 and tumor necrosis factor (TNF)-alpha) was more suppressed. Furthermore, compared to the group without DHNA, histological analyses and radiography showed that bone resorption was suppressed for the DHNA group. Culture experiments using osteoclasts from murine bone marrow showed osteoclast suppression for the DHNA group compared to the group without DHNA.

CONCLUSION

These results show that DHNA has some effects for improving bone mass reduction caused by FK506.

Comparison of Actual Tidal Volume in Neonatal Lung Model Volume Control Ventilation using Three Ventilators

In neonates, small changes in tidal volumes (VT) may lead to complications. Previous studies have shown a significant difference between ventilator-measured tidal volume and tidal volume delivered (actual VT). We evaluated the accuracy of three different ventilators to deliver small VT during volume-controlled ventilation.

We tested Servo 300, 840 ventilator and Evita 4 Neoflow ventilators with lung models simulating normal and injured neonatal lung compliance models. Gas volume delivered from the ventilator into the test circuit (VTV) and actual VT to the test lung were measured using Ventrak respiration monitors at set VT (30 ml). The gas volume increase of the breathing circuit was then calculated.

Tidal volumes of the SV300 and PB840 in both lung models were similar to the set VT and the actual tidal volumes in the injured model (20.7 ml and 19.8 ml, respectively) were significantly less than that in the normal model (27.4 ml and 23.4 ml). PB840 with circuit compliance compensation could not improve the actual VT. VTV of the EV4N in the normal and the injured models (37.8 ml and 46.6 ml) were markedly increased compared with set VT, and actual VT were similar to set VT in the normal and injured model (30.2 ml and 31.9 ml, respectively). EV4N measuring VT close to the lung could match actual VT to almost the same value as the set VT, however the gas volume of the breathing circuit was increased.

If an accurate value for the patient's actual VT is needed, this VT must be measured by a sensor located between the Y-piece and the tracheal tube.

Investigation of the interaction between hydrogen and screw dislocation in silicon by first-principles calculations

The stability of atomic and molecular hydrogen in the vicinity of a screw dislocation in silicon has been investigated using first-principles calculations. The lowest energy configurations are obtained for H atoms located in the dislocation core, suggesting that the segregation of hydrogen is favoured in the dislocation core. It is found that a spontaneous dissociation of H(2) could occur in the dislocation core. Finally, the variation of the interaction energy between hydrogen and the dislocation core as a function of the separation distance has been calculated. There is no sizeable interaction variation for H(2). However, in the case of a single H, an inverse law has been obtained, which can be explained by the anisotropic stress field generated by the insertion of H in the silicon lattice.

Collagenolytic/gelatinolytic enzymes in corneal wound healing

We have documented changes in expression of collagenolytic/gelatinolytic enzymes of the matrix metalloproteinase family (MMP) in healing or ulcerating corneal wounds of rat or rabbit. Correlation of our findings with specific changes in the extracellular matrix of the repair tissue suggests two different roles for the enzymes, MMP-2 and MMP-9. MMP-2 is expressed in undamaged corneal stroma where it may degrade the occasional collagen molecule that becomes damaged. After corneal wounding, expression of this enzyme is increased and much of it appears in the active form. These changes persist for at least seven months, suggesting that MMP-2 is involved in the prolonged process of collagen remodelling in the stromal repair tissue. MMP-9 is expressed in the epithelial layer of repair tissue with a timing suggesting it might participate in controlling resynthesis of the basement membrane. MMP-9 also appears to be involved in degradation of the epithelial basement membrane that precedes corneal ulceration.

Cesarean section and primary pulmonary hypertension: the role of intravenous dexmedetomidine

Primary pulmonary hypertension is a fatal disease that frequently becomes evident in pregnancy. The management of pregnant women with primary pulmonary hypertension poses a number of difficult problems, especially where regional anesthesia is considered to be contraindicated. A 30-year-old woman who developed primary pulmonary hypertension at 23 weeks of pregnancy was transferred to our hospital. Systolic pulmonary artery pressure and plasma brain natriuretic peptide levels were markedly elevated. Nitric oxide inhalation and prostacyclin prevented the progression of cardiac failure and reduced both plasma brain natriuretic peptide and pulmonary artery pressure. Cesarean section was performed at 32 weeks under general anesthesia. A combination of nitric oxide, prostacyclin, nitroglycerin, and dobutamine were administered during surgery. Intravenous dexmedetomidine was specifically used during emergence and recovery from anesthesia. This provided effective pain relief and hemodynamic stability. Throughout the clinical course, brain natriuretic peptide levels was monitored and used as an indicator of cardiac failure.

First case of bacteremia due to chromosome-encoded CfxA3-beta-lactamase-producing Capnocytophaga sputigena in a pediatric patient with acute erythroblastic leukemia

Bacteremia due to Capnocytophaga sputigena occurred in a 4-year and 9-month-old Japanese girl patient with acute erythroblastic leukemia in Shinshu University Hospital, Japan. On her admission to the hospital, she had a temperature of 38.2 degrees C with canker sore. Prior to the commencement of chemotherapy, peripheral blood culture was carried out with the BacT/Alert 3D System ver. 4.00D (bioMerieux Japan Ltd., Tokyo, Japan) using both the PF and the SN bottles. At 48 hrs of incubation, the System showed the positive sign only in the anaerobic SN bottle for bacterial growth. The strain isolated from the SN bottle was morphologically, biochemically, and genetically characterized, and finally identified as Capnocytophaga sputigena. The causative Capnocytophaga sputigena isolate was found to be a beta-lactamase-producer demonstrating to possess cfxA3 gene. The gene responsible for the production of CfxA3-beta-lactamase was proved to be chromosome-encoded, by means of southern hybridization analysis. This was the first case of bacteremia caused by chromosome-encoded CfxA3-beta-lactamase-producing Capnocytophaga sputigena.

Ultrafast photoinduced insulator-ferromagnet transition in the perovskite manganite Gd0.55Sr0.45MnO3

We have investigated the ultrafast spin and charge dynamics in the course of a photoinduced phase transition from an insulator with short-range charge order and orbital order (OO) to a ferromagnetic metal in perovskite-type Gd0.55Sr0.45MnO3. Transient reflectivity changes suggest that the metallic state is formed just after the photoirradiation and decays within approximately 1 ps. The magnetization, however, increases with the time constant of 0.5 ps and decays in approximately 10 ps. The relatively slow increase of the magnetization is attributable to the magnetic-field-induced alignment of ferromagnetic domains in the initially produced metallic state and its slow decay to the partial recovery of the OO.

Extraction of weak transition strengths via the (3He, t) reaction at 420 MeV

Differential cross sections for transitions of known weak strength were measured with the (3He, t) reaction at 420 MeV on targets of 12C, 13C, 18O, 26Mg, 58Ni, 60Ni, 90Zr, 118Sn, 120Sn, and 208Pb. Using these data, it is shown that the proportionalities between strengths and cross sections for this probe follow simple trends as a function of mass number. These trends can be used to confidently determine Gamow-Teller strength distributions in nuclei for which the proportionality cannot be calibrated via beta-decay strengths. Although theoretical calculations in the distorted-wave Born approximation overestimate the data, they allow one to understand the main experimental features and to predict deviations from the simple trends observed in some of the transitions.

Intramedullary hemorrhage caused by arteriovenous malformation: a case of mixed lateral and medial medullary syndrome

A 48-year-old man with no known risk factor for cerebrovascular disease, other than cigarette smoking, experienced the sudden onset of a mixed lateral and medial medullary syndrome. Computed tomography scan failed to show any definite abnormality. Magnetic resonance imaging scans revealed hemorrhage restricted to the left dorsolateral medulla. Angiography showed abnormal arteries originating from the left vertebral artery with small niduses located on the surface of the medulla and contralateral cerebellum. Small brain-stem hemorrhages are a contraindication to thrombolytic or anticoagulant therapy, and therefore must be recognized in the acute stage.

Cementless total hip replacement after previous intertrochanteric valgus osteotomy for advanced osteoarthritis

We present a series of 30 uncemented total hip replacements performed between June 1985 and January 2002 with a mean follow-up of seven years (5 to 20) in 27 patients who had previously undergone a valgus intertrochanteric osteotomy. No further osteotomy was undertaken to enable hip replacement. We used a number of uncemented modular or monoblock femoral components, acetabular components and bearings. The patients were followed up clinically and radiologically. We report 100% survival of the femoral component. One acetabular component was revised at five years post-implantation for aseptic loosening. We noted cortical hypertrophy around the tip of the monoblock stems in six patients. We believe that modular femoral components should be used when undertaking total hip replacement in patients who have previously undergone valgus femoral osteotomy.

Optical control of the magnetic anisotropy of ferromagnetic bilayered manganites

Optical manipulation of the magnetic anisotropy is demonstrated for bilayered manganites, La2-2xSr1+2xMn2O7, by means of femtosecond Kerr-rotation measurements. Upon the photoexcitation on the x=0.32 crystal, the magnetization exhibits the precessional motion for about 1 ns, revealing the directional change of the magnetocrystalline anisotropy from the c axis to the ab plane. This change of the anisotropy induces the nonthermal decrease of the c-axis magnetization component for about 1 ns.

Heart rate variability during high-intensity field exercise in female distance runners

The purposes of this study were to demonstrate the transition of heart rate variability (HRV) during trials in the field and to examine the relationship between peak frequency of high-frequency band (HF) and stride frequency. Ten healthy long-distance college female runners (age 19-21 years) performed a 3000 m realistic time trial. The time-series power spectrum analysis by maximum entropy method was used to evaluate cardiac autonomic nervous activity during the race. Cross-correlation coefficients were calculated to estimate the degree of linear co-ordination between the central peak frequency of HF and stride frequency. Just after starting, the decrease in HF (0.15-1.00 Hz) and a transient increase of low-frequency band (LF)/HF were found. After that, the HF remained at a low level and LF/HF decreased sharply. These findings suggested that the parasympathetic activity was suppressed and sympathetic activity increased just after starting, and the sympathetic activity reached the saturated level according to continuation of high-intensity exercise. In spite of the significant decrease of HRV during trials, peak frequency of HF could be differentiated clearly. The cross-correlation coefficient of peak frequency of HF and stride frequency was from 0.703 to 0.868. This finding indicated that exercise rhythm reflected HRV during high-intensity running in the field.

Enhanced optical magnetoelectric effect in a patterned polar ferrimagnet

A simple method to dramatically enhance the optical magnetoelectric (ME) effect, i.e., nonreciprocal directional birefringence, is proposed and demonstrated for a polar ferrimagnet GaFeO3 as a typical example. We patterned a simple grating with a period of 4 microm on a surface of GaFeO3 crystal and used the diffracted light as a probe. The optical ME modulation signal for the Bragg spot of the order n=1 becomes gigantic in the photon energy 1-4 eV and reaches 1-2% of the bare diffracted light intensity in a magnetic field of 500 Oe. This is amplified by more than 3 orders of magnitude compared to that for the reflection of bulk GaFeO3. Fabricating a photonic crystal will make it possible to lead the way for the practical use of the optical ME effect.