Growth suppression and mitotic defect induced by JNJ-7706621, an inhibitor of cyclin-dependent kinases and aurora kinases

Aurora kinases and cyclin-dependent kinases, which play critical roles in the cell cycle and are frequently overexpressed in a variety of tumors, have been suggested as attractive targets for cancer therapy. JNJ-7706621, a recently identified dual inhibitor of these kinases, is reported to induce cell cycle arrest, endoreduplication, and apoptosis. In the present study, we further investigated the molecular mechanisms underlying these effects. The inhibitor arrested various cells at G2 phase at low concentration, and at both G1 and G2 phases at high concentration. JNJ-7706621 did not prevent localization of Aurora A to the spindle poles, but did inhibit other centrosomal proteins such as TOG, Nek2, and TACC3 in early mitotic phase. Similarly, the drug did not prevent localization of Aurora B to the kinetochore, but did inhibit other chromosomal passenger proteins such as Survivin and INCENP. In the cells exposed to JNJ-7706621 after nocodazole release, Aurora B, INCENP, and Survivin became relocated to the peripheral region of chromosomes, but Plk1 and Prc1 were localized on microtubules in later mitotic phase. Treatment of nocodazole-synchronized cells with JNJ-7706621 was able to override mitotic arrest by preventing spindle checkpoint signaling, resulting in failure of chromosome alignment and segregation. Injection of the drug significantly inhibited the growth of TC135 Ewing's sarcoma cells transplanted into athymic mice by cell cycle arrest and apoptosis. JNJ-7706621 is a unique inhibitor regulating cell cycle progression at multiple points, suggesting that it could be useful for cell cycle analysis and therapy of various cancers, including Ewing's sarcoma.

A study on how a 6-month aerobic exercise program can modify coronary risk factors depending on their severity in middle-aged sedentary women

It is well known that physical exercise can reduce coronary risk factors. But how an aerobic exercise modifies coronary risk factors in relation to severity and physical fitness is still controversial.Fifty-four middle-aged women (mean age, 55 years) completed a 6-month on-site and home-based anaerobic threshold-level exercise program. The changes in coronary risk factor profiles were observed during the pre-intervention and intervention periods. Before the intervention (during control period), most coronary risk factors showed a rather unfavorable trend. After the program, their mean body weight decreased from 56.7 to 55.7 kg (p>0.05) and the proportion of body fat from 30.9 to 27.9% (p>0.05) without any reduction in lean body mass. Systolic blood pressure (SBP) decreased from 129.0 to 125.0 mm Hg (p>0.05) and diastolic blood pressure from 79.5 to 76.6 mm Hg (p>0.05). Fasting plasma glucose (FPG) declined from 109.6 to 103.4 mg/dl (p>0.05). Changes in SBP and FPG were most remarkable in their respective worst tertile. Serum lipids improved only modestly. Maximum oxygen uptake increased from 23.6 to 26.1 ml/kg/min (p>0.01). However, no significant correlations were found between changes in coronary risk factors and those in physical fitness. We conclude that the 6-month aerobic exercise program would modify women's coronary risk factors depending on their initial values, probably independently of the changes in physical fitness.

Gas mediators involved in modulating duodenal HCO3(-) secretion

The secretion of HCO3(-) in the duodenum is increased by mucosal acidification, and this process is modulated by gas mediators such as nitric oxide (NO), hydrogen sulfide (H2S), and carbon monoxide (CO), in addition to prostaglandins (PGs). The secretion is increased by NOR3 (NO donor), NaHS (H2S donor), and CORM-2 (CO donor). The HCO3(-) responses to NOR3 and CORM-2 are attenuated by indomethacin, while that to NaHS is mitigated by indomethacin and L-NAME as well as sensory deafferentation. NOR3 and CORM-2 increase mucosal PGE2 production, while H2S increases mucosal PGE2 content and luminal NO release. The HCO3(-) response to mucosal acidification is attenuated by indomethacin, propargylglycine, and SnPP, each inhibiting PG, H2S and CO production, respectively. The acid-induced duodenal damage is worsened when either PG, H2S or CO is lacking. These findings suggest that 1) NO, H2S, and CO, generated endogenously or exogenously, stimulate HCO3(-) secretion in the duodenum; 2) the stimulatory action of NO and CO is mediated, at least partly, by endogenous PGs, while that of H2S is mediated by PGs and NO as well as sensory neurons; 3) these gas mediators are involved in the local regulation of acid-induced HCO3(-) secretion, in addition to endogenous PGs; 4) the acid-induced duodenal damage is worsened by agents inhibiting the endogenous production of NO, H2S or CO. It is assumed that these gas mediators play a role in maintaining the integrity of the duodenal mucosa by modulating the secretion of HCO3(-).

Risk factors affecting third molar autotransplantation in males: a retrospective survey in dental clinics

The aim of this study was to investigate the risk factors affecting long-term prognosis of autotransplantation of third molars with complete root formation in males at dental clinics. Participating dentists were requested to provide information on transplantations they had undertaken from 1 January 1990 to 31 December 2010. Data on a total of 708 teeth from 637 patients were collected. After data screening and elimination, participants of this study consisted of 183 teeth of 171 males ranging from 20 to 72 years of age (mean age, 44·8 years). The cumulative survival rate was 86·0% at the 5-year mark, 59·1% at 10 years and 28·0% at 15 years. The mean survival time was 134·5 months, as calculated by the Kaplan-Meier method. Single factor analysis using the log-rank test showed that the following factors had significant influence (P < 0·05) on survival of transplanted teeth: periodontal disease as the reason for recipient site tooth extraction, fewer than 25 present teeth and Eichner index Groups B1 to C. Cox regression analysis examined five factors: age, smoking habit, recipient site extraction caused by periodontal disease, fewer than 25 present teeth and Eichner index. This analysis showed that two of these factors were significant: fewer than 25 present teeth was 2·63 (95% CI, 1·03-6·69) and recipient site extraction caused by periodontal disease was 3·80 (95% CI, 1·61-9·01). The results of this study suggest that long-term survival of transplanted teeth in males is influenced not only by oral bacterium but also by occlusal status.

A surveillance of high-level gentamicin-resistant enterococcal bacteremia

Enterococci have recently been recognized as a causative organism of intractable infections, including severe sepsis and infective endocarditis, in immunocompromised patients. This study investigated the epidemiological, microbiological, and prognostic characteristics of high-level gentamicin-resistant (HLGR) enterococcal bacteremia, including severe cases of infective endocarditis, in Japan. A total of 155 enterococcal bacteremia episodes were identified between July 2007 and December 2009. HLGR strains accounted for 28% of all enterococcal strains: HLGR Enterococcus faecalis/Enterococcus faecium strains accounted for 32%/24%. The 30-day mortality rate was 31%. There was no significant difference in the 30-day mortality rates between HLGR and non-HLGR enterococcal bacteremia. There were two cases of HLGR enterococcal endocarditis, which were successfully treated with ampicillin plus ceftriaxone. We consider it important to examine the presence or absence of HLGR strains in all cases of intractable enterococcal infection, especially infective endocarditis.

Rapidly progressive fatal hemorrhagic pneumonia caused by Stenotrophomonas maltophilia in hematologic malignancy

BACKGROUND

Pneumonia caused by Stenotrophomonas maltophilia is rare, but can be lethal in severely immunocompromised patients. However, its clinical course remains unclear.

PATIENTS AND METHODS

Patients with pneumonia caused by S. maltophilia in Toranomon Hospital (890 beds, Tokyo, Japan) were reviewed retrospectively between April 2006 and March 2010.

RESULTS

During the study period, 10 cases of S. maltophilia pneumonia were identified. Seven patients had acute myeloid leukemia, 2 had myelodysplastic syndrome, and 1 had malignant lymphoma. All patients developed symptoms after allogeneic hematopoietic stem cell transplantation (HSCT). Five patients received first cord blood transplantation (CBT), 4 patients received second CBT, and 1 patient received first peripheral blood stem cell transplantation (PBSCT). The overall incidence of S. maltophilia pneumonia among 508 patients who received HSCT during the period was 2.0%. The incidence was 0% (0/95) in patients after bone marrow transplantation, 0.8% (1/133) after PBSCT, and 3.2% (9/279) after CBT. Pneumonia developed a median of 13.5 days (range, 6-40) after transplantation. At onset, the median white blood cell count was 10/μL (range, 10-1900), and the median neutrophil count was 0/μL (range, 0-1720). In all patients, S. maltophilia bacteremia developed with bloody sputum or hemoptysis. The 28-day mortality rate was 100%; the median survival after onset of pneumonia was 2 days (range, 1-10).

CONCLUSIONS

Hemorrhagic S. maltophilia pneumonia rapidly progresses and is fatal in patients with hematologic malignancy. Attention should be particularly paid to the neutropenic phase early after HSCT or prolonged neutropenia due to engraftment failure. A prompt trimethoprim-sulfamethoxazole-based multidrug combination regimen should be considered to rescue suspected cases of S. maltophilia pneumonia in these severely immunosuppressed patients.

MRI of the anatomical structures of the knee: the proton density-weighted fast spin-echo sequence vs the proton density-weighted fast-recovery fast spin-echo sequence

OBJECTIVE

The purpose of this study was to compare the proton-density (PD)-weighted fast spin-echo (FSE) and fast-recovery FSE (FRFSE) sequences for the evaluation of the anatomical structures of the knee.

METHOD

24 healthy volunteers who underwent MRI by both sagittal PD-weighted FSE and FRFSE sequences were evaluated. The signal-to-noise ratio, contrast-to-noise ratio (CNR) and anatomical detail visualisation were compared for the two techniques.

RESULTS

The mean CNRs and reader ratings for both readers were significantly higher for the PD-weighted FRFSE images than for the PD-weighted FSE images in the cartilages/the femorotibial joint effusion and the cruciate ligaments/the effusion around the cruciate ligaments; however, the mean CNRs and reader ratings for both readers were significantly higher for the PD-weighted FSE sequences than for the PD-weighted FRFSE sequences in the cartilages/the menisci and the cruciate ligaments.

CONCLUSIONS

The main advantages of the PD-weighted FRFSE sequence are the increase in contrast between fluid and non-fluid tissues and the time saved by using the procedure. However, in the absence of joint effusion, the PD-weighted FRFSE sequence generates a poorer contrast between the cartilage and meniscus, the cruciate ligaments and fat of the intercondylar fossa.

P5-13-23: Individualized Treatment Strategies for HER2−Negative Breast Cancer Subtypes

Background Human epidermal growth factor receptor (HER2)-negative breast cancers are more heterogeneous than HER2−positive cancers, and tailored treatment is therefore required for luminal A and triple-negative breast cancer subtypes (LABC and TNBC). We therefore examined predictive factors for the efficacy of standard chemotherapy in LABC and TNBC subtypes.

Methods A total of 109 LABC and 61 TNBC patients were treated with standard neoadjuvant chemotherapy (NAC) consisting of an anthracycline and/or taxane. The pathological treatment response and prognosis were examined for each subtype. Expression levels of the following factors were examined in association with quasi-pathological complete response (QpCR): estrogen- and progesterone-receptor (ER and PgR) status, HER2, nuclear grade, MIB-1, p53, topoisomerase IIα (topoIIα), cytokeratin (CK) 5/6 and epidermal growth factor (EGFR).

Results QpCR rates in LABC and TNBC were 9.1% (10/109) and 54.1% (33/61), respectively. In LABC, the expression of PgR tended to be inversely associated with pathological response (p=0.087), while in TNBC, increased expression of topoIIa (p=0.006) and MIB-1 (p=0.018) were identified as predictors of QpCR. TopoIIα expression was also significantly associated with pathological response in multivariate analysis (p=0.014). The QpCR rate was higher in TNBC lacking CK5/6 and/or EGFR expression, defined as non-basal subtype (p=0.053).

Conclusions Low expression of PgR may be a possible predictor of the efficacy of chemotherapy in LABC, while a high level of proliferative activity, indicated by topoIIa and MIB-1, is associated with chemosensitivity in TNBC. Further subclassification into basaland non basal-subtypes may also be helpful for the development of individualized treatments.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-13-23.

Cunninghamella bertholletiae pneumonia showing a reversed halo sign on chest computed tomography scan following cord blood transplantation

This is the first reported case of a patient who developed fungal pneumonia caused by Cunninghamella bertholletiae (= C. elegans) following cord blood transplantation and who showed a reversed halo sign on a chest computed tomography scan (CT). In addition, the pathological findings related to the reversed halo sign are described in detail for the first time. The patient died due to respiratory failure and at autopsy, a consolidation corresponding to the reversed halo sign noted on CT was found histologically to be composed of a central infarct with some retained air spaces surrounded by a peripheral ring-like hemorrhagic band. Pulmonary vasculatures were occluded by thrombi containing numerous Zygomycetes hyphae within the central infarct and less frequently along the surrounding hemorrhagic band. A reversed halo sign may be an early marker to initiate preemptive therapy against Zygomycetes including C. bertholletiae.

Accumulation of sub-100 nm polymeric micelles in poorly permeable tumours depends on size

A major goal in cancer research is to develop carriers that can deliver drugs effectively and without side effects. Liposomal and particulate carriers with diameters of ∼100 nm have been widely used to improve the distribution and tumour accumulation of cancer drugs, but so far they have only been effective for treating highly permeable tumours. Here, we compare the accumulation and effectiveness of different sizes of long-circulating, drug-loaded polymeric micelles (with diameters of 30, 50, 70 and 100 nm) in both highly and poorly permeable tumours. All the polymer micelles penetrated highly permeable tumours in mice, but only the 30 nm micelles could penetrate poorly permeable pancreatic tumours to achieve an antitumour effect. We also showed that the penetration and efficacy of the larger micelles could be enhanced by using a transforming growth factor-β inhibitor to increase the permeability of the tumours.

Survey on medical records and EHR in Asia-Pacific region: languages, purposes, IDs and regulations

OBJECTIVES

To clarify health record background information in the Asia-Pacific region, for planning and evaluation of medical information systems.

METHODS

The survey was carried out in the summer of 2009. Of the 14 APAMI (Asia-Pacific Association for Medical Informatics) delegates 12 responded which were Australia, China, Hong Kong, India, Indonesia, Japan, Korea, New Zealand, the Philippines, Singapore, Thailand, and Taiwan.

RESULTS

English is used for records and education in Australia, Hong Kong, India, New Zealand, the Philippines, Singapore and Taiwan. Most of the countries/regions are British Commonwealth. Nine out of 12 delegates responded that the second purpose of medical records was for the billing of medical services. Seven out of nine responders to this question answered that the second purpose of EHR (Electronic Health Records) was healthcare cost cutting. In Singapore, a versatile resident ID is used which can be applied to a variety of uses. Seven other regions have resident IDs which are used for a varying range of purposes. Regarding healthcare ID, resident ID is simply used as healthcare ID in Hong Kong, Singapore and Thailand. In most cases, disclosure of medical data with patient's name identified is allowed only for the purpose of disease control within a legal framework and for disclosure to the patient and referred doctors. Secondary use of medical information with the patient's identification anonymized is usually allowed in particular cases for specific purposes.

CONCLUSION

This survey on the health record background information has yielded the above mentioned results. This information contributes to the planning and evaluation of medical information systems in the Asia-Pacific region.

NFKBIL1 confers resistance to experimental autoimmune arthritis through the regulation of dendritic cell functions

We and others have reported that human NF-κB inhibitor-like-1 (NFKBIL1) was a putative susceptible gene for autoimmune diseases such as rheumatoid arthritis (RA). However, its precise role in the pathogenesis of RA is still largely unknown. In this study, we generated transgenic mice expressing human NFKBIL1 (NFKBIL1-Tg) and examined whether NFKBIL1 plays some role(s) in the development of autoimmune arthritis. In both a collagen-induced arthritis model and a collagen antibody-induced arthritis model, NFKBIL1-Tg mice showed resistance to arthritis compared to control mice, indicating that the gene product of NFKBIL1 was involved in the control of thusly induced arthritis. Total spleen cells of NFKBIL1-Tg mouse showed decreased proliferation to mitogenic stimuli, consistent with its resistance to arthritis. Unexpectedly, purified T cells of NFKBIL1-Tg mouse showed increased proliferation and cytokine production. This apparent discrepancy was accounted for by the impaired functions of antigen-presenting cells of NFKBIL1-Tg mouse; both T/B cell-depleted spleen cells and bone marrow-derived dendritic cells of the Tg mouse induced less prominent proliferation and IL-2 production of T cells. Furthermore, dendritic cells (DCs) derived from NFKBIL1-Tg mouse showed lower expression of co-stimulatory molecules and decreased production of inflammatory cytokines when they were activated by lipopolysaccharide. Taken together, these results indicated that NFKBIL1 affected the pathogenesis of RA at least in part through the regulation of DC functions.

[Importance of JSLM2009 guideline and a message regarding the next set of guideline]

The Japanese Society of Laboratory Medicine has established the JSLM2009 guideline. This guideline is very useful for performing laboratory examinations precisely. However, further improvements in this guideline are desirable for the future. I think that JSLM2009 guideline has the following advantages and disadvantages for clinicians.

ADVANTAGES

(1) JSLM 2009 guideline has referred to many guidelines from other medical societies in order to maintain comparability among guidelines. (2) Many figures have been to help clinician understand the strategy of laboratory medicine. (3) There are also many recommendations indicating when clinicians should consult an expert. (4) JSLM2009 guideline indicates whether or not each laboratory examination is covered by Japanese health insurance.

DISADVANTAGES

(1) There are some ambiguities that may lead to mistakes. (2) Descriptions of the sensitivity and specificity of laboratory medicine are insufficient. (3) The evidence level supporting various aspects of laboratory medicine has not been described. (4) There are certain areas that are based on insufficient evidence. In this context, I consider that the next set of guideline should be based on evidence that adequately supports laboratory medicine, while maintaining the current advantages of JSLM2009 guideline.

Longitudinal versus cross-sectional evaluations of leukocyte telomere length dynamics: age-dependent telomere shortening is the rule

BACKGROUND

Leukocyte telomere length (LTL) is considered a biomarker of human aging and based on cross-sectional studies it shortens with age. However, longitudinal studies reported that many adults display LTL lengthening.

METHODS

Using Southern blots, we compared cross-sectional rates of age-related LTL change across a ∼20 year age range with those based on longitudinal evaluations in three surveys (S1, S2, and S3) with three time intervals: S1-S2 (5.8 years), S2-S3 (6.6 years), and S1-S3 (12.4 years). Hierarchical linear modeling was used to explore LTL dynamics using LTL data from S1, S2, and S3.

RESULTS

Cross-sectionally, mean LTL shortenings were 24.6, 25.4, and 23.6 bp/y at S1, S2, and S3, respectively. Longitudinally, more variation was observed in the rate of LTL change during the shorter than longer follow-up periods. Furthermore, using simple differences in LTL, 14.4% and 10.7% of individuals displayed LTL lengthening during S1-S2 and S2-S3, respectively, but only 1.5% during S1-S3 (p < 0.001). The estimated mean rate of LTL shortening based on averaging empirical Bayes' estimates of LTL from a parsimonious hierarchical linear modeling model was 31 bp/y with a range from 23 to 47 bp/y with none of the participants showing LTL lengthening over the average 12.4 years of follow-up.

CONCLUSIONS

As aging displays a unidirectional progression, it is unlikely that LTL elongates with age. LTL elongation in longitudinal studies primarily reflects measurement errors of LTL in relation to the duration of follow-up periods.

Health IT in Asia-Pacific region

APAMI 2009 was held in Hiroshima, Japan, on November 22-24, 2009. This issue includes two selected papers recommended by the programming committee co-chairs. They are "Lessons Learned from Data Mining of WHO Mortality Database" and "Survey on Medical Records and EHR in Asia-Pacific Region - Languages, Purposes, IDs and Regulations". The theme of APAMI 2009 was "What are the medical records for?" A Hiroshima episode; Medical Records at Dr. Ban's Clinic, 9 km from the Epicenter of A-Bomb, is included, which lets us think of the fundamental purpose of medical records.

Abstract P1-01-16: Evaluation of Sentinel Node Biopsy Using a Combined Dye and Fluorescence Method for Breast Cancer

Background: Sentinel lymph node (SLN) dissection is now widely accepted for staging the axilla in patients with breast cancer. At present, several methods are used to detect SLN. A combination of blue dye and radioactive colloid has been described previously as a superior method for detecting SLN in breast cancer patients. However, use of radioactive colloids is not generally available for various reasons in Japan. SLN detection guided by indocyanine green (ICG) fluorescence could emerge as a new method for SLN biopsy. The aim of this study was to evaluate sentinel node biopsy using a combined dye and fluorescence method for breast cancer.

Methods: Fifty-eight patients with clinically node-negative breast cancer were examined between April 2008 and March 2009 at Yokohama City University Hospital. Intradermal injections of 20 mg/5 ml of indigo carmine and 0.5 mg/0.1 ml of ICG were made into the upper-lateral region of the periareolar area. Subcutaneus lymphatic channels draining from the areola to the axilla were visible under fluorescence within a few minutes. SLNs were then dissected under direct vision supported by fluorescence navigation. Palpable lymph nodes were also dissected. All SLNs were histologically evaluated by 2-mm serial section and staining with hematoxylin and eosin. Patients with positive SLNs underwent axillary lymph node dissection (ALND), while patients with negative SLN did not.

Results: SLNs were identified in 58 patients (100%). ICG fluorescence imaging was compared with indigo carmine dye, and SLNs were identified in 57 and 52 patients, respectively (detection rate: ICG, 98.3%; dye, 89.7%). The mean number of excised SLNs was 2.72. Mean numbers of lymph nodes showing fluorescence and blue stain from injected dye were 2.31 and 1.41, respectively. Eight of 58 patients (13.8%) had metastases detected in the SLN, so ALND were subsequently performed. Five of these cases were without metastases at non-SLN that were dissected. One patient showed metastasis in a SLN that was positive for fluorescence, but negative for blue dye. Among all cases, 1 patient (1.7%) showed an SLN without fluorescence or blue staining, and this case was detected by palpation only.

Conclusion: Combined use of dye and fluorescence method identified SLNs effectively.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-01-16.

Abstract P6-11-13: Phase I Study of Combined S-1 Plus Weekly Paclitaxel Therapy in Patients with Metastatic Breast Cancer

Introduction: S-1, a novel anticancer compound, contains tegafur, a prodrug of fluorouracil (FU), 5-chloro-2.4-dihydroxypyridine, which prevents FU degradation, and potassium oxonate, which prevents drug-induced diarrhea, has a broad spectrum of activity against gastric, colorectal, head & neck, and breast cancers. While combined S-1 with cisplatin or paclitaxel (PAC) therapy is feasible and highly active against gastrointestinal cancer, the feasibility in breast cancer patients has not yet been clarified. We conducted a phase I study of combined S-1 plus weekly PAC therapy (S-1/PAC) to determine the maximum tolerated dose (MTD), recommended dose (RD) and dose-limiting toxicities (DLT) in patients (pts) with HER2-negative, taxane-naïve metastatic breast cancer (MBC).

Methods: S-1 was administered orally from day 1 through day 14 and PAC was administered intravenously on days 1, 8 and 15 of each 28-day cycle. Since S-1 is prescribed at the dose of 80mg/m2 in monotherapy, the primary dose levels (level 1) were set at 65 and 70mg/m2, respectively. The final dose (level 3) was set at 80mg/m2 for each drugs. DLT was defined over 2 cycles.

Results: Ten MBC pts were enrolled in the study. No DLTs were documented. Although grade 1 or 2 adverse events were seen in all pts, no cases of febrile neutropenia or Gr 4 neutropenia were observed. Of the 8 evaluable pts, 3 pts achieved partial response and 4 pts had stable disease.

Conclusion: Based on the results of this study, RD was determined to be 80mg/m2 for either drugs. We conclude that S-1/PAC was well-tolerated and highly active against HER2-negative MBC.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-11-13.

[Experience with surgical resections of metachronous liver and bilateral pulmonary metastases from gastric cancer]

A 75-year-old female patient underwent distal gastrectomy with lymph node dissection for gastric cancer. Six months later, computed tomography (CT) and magnetic resonance imaging (MRI) revealed liver metastasis and radio frequency ablation (RFA) was performed. Ten months later, she underwent a partial hepatectomy for recurrent hepatic metastasis. Then, pulmonary nodules were revealed 1 year later, and segmentectomy (S4 + S5) for left pulmonary metastasis and wedge resection for right middle lobe pulmonary metastasis were sequentially performed after 9 months and 10 months observation by CT, respectively. Two years have passed since the last surgery, and the patient has survived more than 5 years since initial gastrectomy.

High resolution, low hν photoelectron spectroscopy with the use of a microwave excited rare gas lamp and ionic crystal filters

The need for not only bulk sensitive but also extremely high resolution photoelectron spectroscopy for studying detailed electronic structures of strongly correlated electron systems is growing rapidly. Moreover, easy access to such a capability in one's own laboratory is desirable. Demonstrated here is the performance of a microwave excited rare gas (Xe, Kr, and Ar) lamp combined with ionic crystal filters (sapphire, CaF(2), and LiF), which can supply three strong lines near the photon energy of hnyu hν=8.4, 10.0, and 11.6 eV, with the hν resolution of better than 600 μeV for photoelectron spectroscopy. Its performance is demonstrated on some materials by means of both angle-integrated and angle-resolved measurements.

Mapping of susceptibility locus for endometriosis within the HLA region using microsatellite markers in Japanese women

Endometriosis is a female disorder characterized by the presence of uterine endometrial tissue in ectopic loci. Previous studies reported a higher prevalence of particular human leukocyte antigen (HLA) in endometriosis. In order to confirm the association between endometriosis and the HLA region, 15 polymorphic microsatellite markers distributed in the HLA class II to class III region were subjected to association analysis by polymerase chain reaction (PCR)-based DNA typing of 89 patients and 136 healthy controls. Statistical analysis of the allelic frequency at each microsatellite locus showed that there were no statistically significant differences in the allele frequency distributions between the cases and controls. This finding suggests that the etiology of endometriosis does not involve the HLA class II genomic region and a portion of class III genomic region in the Japanese population.

Multilayer white light-emitting organic electroluminescent device

Organic electroluminescent devices are light-emitting diodes in which the active materials consist entirely of organic materials. Here, the fabrication of a white light-emitting organic electroluminescent device made from vacuum-deposited organic thin films is reported. In this device, three emitter layers with different carrier transport properties, each emitting blue, green, or red light, are used to generate white light. Bright white light, over 2000 candelas per square meter, nearly as bright as a fluorescent lamp, was successfully obtained at low drive voltages such as 15 to 16 volts. The applications of such a device include paper-thin light sources, which are particularly useful for places that require lightweight illumination devices, such as in aircraft and space shuttles. Other uses are a backlight for liquid crystal display as well as full color displays, achieved by combining the emitters with micropatterned color filters.

Diffusion model of intergroup selection, with special reference to evolution of an altruistic character

Assume a diploid species consisting of an infinite number of competing demes, each having N(e) reproducing members and in which mating is at random. Then consider a locus at which a pair of alleles A and A' are segregating, where A' is the "altruistic allele," which has selective disadvantage s' relative to A with respect to individual selection, but which is beneficial for a deme in competition with other demes; namely, a deme having A' with frequency x has the advantage c(x - x) relative to the average deme, where c is a positive constant and x is the average of x over the species. Let varphi = varphi(x;t) be the distribution function of x among demes in the species at time t. Then, we have partial differentialvarphi/ partial differentialt = L(varphi) + c(x - x)varphi, where L is the Kolmogorov forward differential operator commonly used in population genetics [i.e., L = (1/2) ( partial differential(2)/ partial differentialx(2))V(deltax) - ( partial differential/ partial differentialx)M(deltax)], and M(deltax) and V(deltax) stand for the mean and variance of the change in x per generation within demes. As to migration, assume Wright's island model and denote by m the migration rate per deme per generation. By investigating the steady state, in which mutation, migration, random drift, and intra- and interdeme selection balance each other, it is shown that the index D = c/m - 4N(e)s' serves as a good indicator for predicting which of the two forces (i.e., group selection or individual selection) prevails; if D > 0, the altruistic allele predominates, but if D < 0, it becomes rare and cannot be established in the species.

Genetic variability and effective population size when local extinction and recolonization of subpopulations are frequent

If a population (species) consists of n haploid lines (subpopulations) which reproduce asexually and each of which is subject to random extinction and subsequent replacement, it is shown that, at equilibrium in which mutational production of new alleles and their random extinction balance each other, the genetic diversity (1 minus the sum of squares of allelic frequencies) is given by 2N(e)v/(1 + 2N(e)v), where [Formula: see text] in which N is the harmonic mean of the population size per line, n is the number of lines (assumed to be large), lambda is the rate of line extinction, and v is the mutation rate (assuming the infinite neutral allele model). In a diploid population (species) consisting of n colonies, if migration takes place between colonies at the rate m (the island model) in addition to extinction and recolonization of colonies, it is shown that effective population size is [Formula: see text] If the rate of colony extinction (lambda) is much larger than the migration rate of individuals, the effective population size is greatly reduced compared with the case in which no colony extinctions occur (in which case N(e) = nN). The stepping-stone type of recolonization scheme is also considered. Bearing of these results on the interpretation of the level of genetic variability at the enzyme level observed in natural populations is discussed from the standpoint of the neutral mutation-random drift hypothesis.

Purification, primary structure, and homology relationships of a chloroplast ribosomal protein

A chloroplast ribosomal protein that showed immunological homology to Escherichia coli ribosomal protein L12 was purified from spinach (Spinacia oleracea) leaves and its primary structure was determined by manual micro Edman degradation. The protein is composed of 130 amino acid residues and has M(r) 13,576. It shows structural features characteristic of the L12 proteins of eubacterial 70S ribosomes (e.g., identical amino acid residues in about 50% of the sequence) but no apparent homology to the L12-type proteins of eukaryotic cytoplasmic 80S ribosomes. The homology to eubacterial proteins is highest in the COOH-terminal region (70%) and low in the NH(2)-terminal region (<20%).

Genetic variability maintained in a finite population under mutation and autocorrelated random fluctuation of selection intensity

By using the diffusion equation method, the level of genetic variability maintained under mutation pressure in a finite population is investigated, assuming autocorrelated random fluctuation of selection intensity. An appropriate mathematical model was formulated to treat the change of gene frequencies, incorporating mutation pressure and fluctuating selection. Extensive Monte Carlo simulation experiments were also performed to supplement the theoretical treatments. Excellent agreement between the two results suggests the validity of the present diffusion model for the autocorrelated selection. One of the most important findings from the simulation studies is that mutations and random sampling drift largely determine the level of genetic variability, and that the presence of autocorrelated selection can significantly lower genetic variability only when its strength, as measured by the cumulative variance of selection intensity, is larger than about 10(3) times the mutation rate. It is pointed out that the effects of both mutations and random sampling drift have to be incorporated in order to assess the role of various factors for the maintenance of genetic variability in natural populations.

Average time until fixation of a mutant allele in a finite population under continued mutation pressure: Studies by analytical, numerical, and pseudo-sampling methods

We consider a single locus, and denote by A the wild-type allele and by A' the mutant allele that is produced irreversibly in each generation from A at the rate v. Let 1 + s, 1 + h, and 1 be, respectively, the relative fitnesses of mutant homozygote A'A', mutant heterozygote A'A, and wild-type homozygote AA. Then, it is shown, on the basis of the diffusion equation method, that the average time until fixation of the mutant allele (A') in a randomly mating population of effective size N(e), given that the initial frequency is p, is [Formula: see text] in which B(x) = (S/2)x(2) + Hx(1 - x), S = 4N(e)s, H = 4N(e)h, and V = 4N(e)v. Of particular interest are the cases in which the mutant allele is deleterious (s = -s', s' > 0). Three cases are considered; the mutant is: (i) completely dominant s = h = -s', (ii) completely recessive s = -s', h = 0, and (iii) semidominant s = -s', h = -s'/2, in which s' is the selection coefficient against the mutant homozygote. It is shown that the average time until fixation is shorter when the deleterious mutant allele is dominant than when it is recessive if 4N(e)v is larger than 1. On the other hand, the situation is reversed if 4N(e)v is smaller than 1. It is also shown that for a mutant allele for which N(e)s' > 10, it takes such a long time until fixation that we can practically ignore the occurrence of random fixation of a deleterious allele under continued mutation pressure. To supplement the analytical treatment, extensive simulation experiments were performed by using a device called the pseudo-sampling variable, which can enormously accelerate the process of simulation by a computer. This method simulates the diffusion process itself rather than the binominal sampling process (in population genetics the diffusion model is usually regarded as an approximation of the discrete binomial sampling process).

Model of effectively neutral mutations in which selective constraint is incorporated

Based on the idea that selective neutrality is the limit when the selective disadvantage becomes indefinitely small, a model of neutral (and nearly neutral) mutations is proposed that assumes that the selection coefficient (s') against the mutant at various sites within a cistron (gene) follows a Gamma distribution; f(s') = alpha(beta)e(-alphas')s'(beta-1)/Gamma(beta), in which alpha = beta/ s' and s' is the mean selection coefficient against the mutants ( s' > 0; 1 [unk] beta > 0). The mutation rate for alleles whose selection coefficients s' lie in the range between 0 and 1/(2N(e)), in which N(e) is the effective population size, is termed the effectively neutral mutation rate (denoted by v(e)). Using the model of "infinite sites" in population genetics, formulas are derived giving the average heterozygosity ( h(e)) and evolutionary rate per generation (k(g)) in terms of mutant substitutions. It is shown that, with parameter values such as beta = 0.5 and s' = 0.001, the average heterozygosity increases much more slowly as N(e) increases, compared with the case in which a constant fraction of mutations are neutral. Furthermore, the rate of evolution per year (k(1)) becomes constant among various organisms, if the generation span (g) in years is inversely proportional to radicalN(e) among them and if the mutation rate per generation is constant. Also, it is shown that we have roughly k(g) = v(e). The situation becomes quite different if slightly advantageous mutations occur at a constant rate independent of environmental conditions. In this case, the evolutionary rate can become enormously higher in a species with a very large population size than in a species with a small population size, contrary to the observed pattern of evolution at the molecular level.

Efficiency of truncation selection

Truncation selection is known to be the most efficient form of directional selection. When this is modified so that the fitness increases linearly over a range of one or two standard deviations of the value of the selected character, the efficiency is reduced, but not greatly. When truncation selection is compared to a system in which fitness is strictly proportional to the character value, the relative efficiency of truncation selection is given by f(c)/sigma, in which f(c) is the ordinate of the frequency distribution at the truncation point and sigma is the standard deviation of the character. It is shown, for mutations affecting viability in Drosophila, that truncation selection or reasonable departures therefrom can reduce the mutation load greatly. This may be one way to reconcile the very high mutation rate of such genes with a small mutation load. The truncation model with directional selection is appropriate for this situation because of the approximate additivity of these mutations. On the other hand, it is doubtful that this simple model can be applied to all genes affecting fitness, for which there are intermediate optima and antagonistic selection among components with negative correlations. Whether nature ranks and truncates, or approximates this behavior, is an empirical question, yet to be answered.

Avian malaria parasites share congeneric mosquito vectors

Assessing parasite specificity to vector is crucial to understanding the emergence of vector-borne diseases and the evolution of parasite diversity. Avian malaria parasites have a cosmopolitan distribution and broad avian host range, which together predict they are vector generalists, but little is known about parasite-vector associations in the wild. We tested this prediction by asking if 5 different mosquito species, known to feed on birds and abundant in the northeastern United States, were naturally infected in the field with identical avian Plasmodium spp. lineages. Mosquitoes were not pooled but rather analyzed individually, and, possibly as a result, lineage diversity was higher than reported in previous avian malaria vector studies. Plasmodium spp. lineages were rare in Aedes canadensis and absent in Aedes aurifer and Culiseta melanura. We sequenced a standard Plasmodium cytochrome b marker from Culex pipiens pipiens, Culex restuans, and Ae. canadensis. Most Plasmodium clades were shared by Cx. pipiens and Cx. restuans. In addition, 4 individual lineages were shared by both mosquito species, including the most common lineage. One Plasmodium clade, however, was only found in Cx. restuans. We therefore found limited support for our prediction that avian Plasmodium spp. vector breadth accompanies host breadth. The association of both Culex species with most Plasmodium clades, and the presence of a single parasite lineage in 3 mosquito species representing 2 genera, suggests that avian Plasmodium species are not tightly coevolved with vector species.