Sphingomyelin metabolism underlies Ras excitability for efficient cell migration and chemotaxis.

In eukaryotic motile cells, the active Ras (Ras-GTP)-enriched domain is generated in an asymmetric manner on the cell membrane through the excitable dynamics of an intracellular signaling network. This asymmetric Ras signaling regulates pseudopod formation for both spontaneous random migration and chemoattractant-induced directional migration. While membrane lipids, such as sphingomyelin and phosphatidylserine, contribute to Ras signaling in various cell types, whether they are involved in the Ras excitability for cell motility is unknown. Here we report that functional Ras excitability requires the normal metabolism of sphingomyelin for efficient cell motility and chemotaxis. The pharmacological blockade of sphingomyelin metabolism by an acid-sphingomyelinase inhibitor, fendiline, and other inhibitors suppressed the excitable generation of the stable Ras-GTP-enriched domain. The suppressed excitability failed to invoke enough basal motility to achieve directed migration under shallow chemoattractant gradients. The fendiline-induced defects in Ras excitability, motility and stimulation-elicited directionality were due to an accumulation of sphingomyelin on the membrane, which could be recovered by exogenous sphingomyelinase or phosphatidylserine without changing the expression of Ras. These results indicate a novel regulatory mechanism of the excitable system by membrane lipids, in which sphingomyelin metabolism provides a membrane environment to ensure Ras excitation for efficient cellular motility and chemotaxis.Key words: cell polarity, cell migration, Ras, excitability, sphingomyelin.

The prevalence of VAIN, CIN, and related HPV genotypes in Japanese women with abnormal cytology.

Vaginal intraepithelial neoplasia (VAIN) is often found by chance. We investigated the prevalence of VAIN and related human papillomavirus (HPV) types in comparison with cervical intraepithelial neoplasia (CIN). This study enrolled 648 women who were referred to the outpatient clinic of Kanazawa Medical University Hospital for abnormal cytology from January 2009 to January 2019. HPV genotypes were determined using Genosearch-31 + 4, which can detect 35 different HPV types. Colposcopy was performed at the first visit by an experienced gynecological oncologist. Among 611 subjects with squamous cell lesions, 107 (17.5%) VAIN cases were identified, and 67 (11.0%) women had both VAIN and CIN. Ultimately, 72 VAIN1, 15 VAIN2/3, 203 CIN1, 249 CIN2/3, 32 cervical squamous cell carcinomas (SCC), and one vaginal SCC (Vag-SCC) were identified. The prevalences of VAIN1, VAIN2/3, and Vag-SCC were 35.5%, 6.0%, and 3.1% of equivalent cervical lesions, respectively. The VAIN patients were older than the CIN patients (P = .002). About half of the VAIN cases were diagnosed during the follow-up. Multiple HPV infections were found in 42.9% of the VAIN and CIN patients. HPV52, 16, 51, 53, and 56 were the most common types in VAIN, whereas HPV16, 52, 58, 51, and 31 predominated in CIN. HPV18 was rare in VAIN, HPV58 was more common in CIN than in VAIN, and HPV53 and HPV73 were more common in VAIN. In conclusion, VAIN1 was identified more frequently than we expected. Various HPV types were identified in the vagina, which is likely a reservoir for HPV.

Unique Directional Motility of Influenza C Virus Controlled by Its Filamentous Morphology and Short-Range Motions.

Influenza virus motility is based on cooperation between two viral spike proteins, hemagglutinin (HA) and neuraminidase (NA), and is a major determinant of virus infectivity. To translocate a virus particle on the cell surface, HA molecules exchange viral receptors and NA molecules accelerate the receptor exchange of HA. This type of virus motility was recently identified in influenza A virus (IAV). To determine if other influenza virus types have a similar receptor exchange mechanism-driven motility, we investigated influenza C virus (ICV) motility on a receptor-fixed glass surface. This system excludes receptor mobility, which makes it more desirable than a cell surface for demonstrating virus motility by receptor exchange. Like IAV, ICV was observed to move across the receptor-fixed surface. However, in contrast to the random movement of IAV, a filamentous ICV strain, Ann Arbor/1/50 (AA), moved in a straight line, in a directed manner, and at a constant rate, whereas a spherical ICV strain, Taylor/1233/47 (Taylor), moved randomly, similar to IAV. The AA and Taylor viruses each moved with a combination of gradual (crawling) and rapid (gliding) motions, but the distances of crawling and gliding for the AA virus were shorter than those of the Taylor virus. Our findings indicate that like IAV, ICV also has a motility that is driven by the receptor exchange mechanism. However, compared with IAV movement, filamentous ICV movement is highly regulated in both direction and speed. Control of ICV movement is based on its specific motility employing short crawling and gliding motions as well as its own filamentous morphology.IMPORTANCE Influenza virus enters into a host cell for infection via cellular endocytosis. Human influenza virus infects epithelial cells of the respiratory tract, the surfaces of which are hidden by abundant cilia that are inactive in endocytosis. An open question is the manner by which the virus migrates to endocytosis-active domains. In analyzing individual virus behaviors through single-virus tracking, we identified a novel function of the hemagglutinin and esterase of influenza C virus (ICV) as the motility machinery. Hemagglutinin iteratively exchanges a viral receptor, causing virus movement. Esterase degrades the receptors along the trajectory traveled by the virus and prevents the virus from moving backward, causing directional movement. We propose that ICV has a unique motile machinery directionally controlled via hemagglutinin sensing the receptor density manipulated by esterase.

Comparison of the digene hybrid capture 2 and Roche cobas 4800 HPV tests for detection of CIN2+ in a referral population in Japan.

To examine validity of the hybrid capture-2 and cobas 4800 HPV tests, 396 women including 188 women visiting for cancer screening, and 208 referral cases were examined with both HPV tests and the liquid-based cervical Pap test. Concordant results between the HPV assays were observed in 333 cases (coincident rates; 84.1%, kappa value; 0.682). The sensitivity for CIN2+ was 98.6% (69/70) and 82.9% (58/70) for HC2 and cobas 4800 (McNemar's test; P = 0.0026). The sensitivity for CIN3+ was 97.2% (35/36) and 83.3% (30/36) (Not significant, P = 0.0736). The specificities for CIN2+ or CIN3+ did not differ between the tests. The HPV16, 52, 18, 31, and 58 were the most common types in CIN2+ cases. Reasonable sensitivity for HPV52, and cross-hybridization with some probable high-risk HPV type such as HPV82 explain the higher sensitivity of HC2 than cobas 4800 in detection of CIN2+ in a referral population in Japan.

[A Case of Advanced Gastric Cancer with Severe Jaundice from Multiple Liver Metastases That Was Significantly Improved after Capecitabine plus Oxaliplatin Treatment].

A 74-year-old man with advanced gastric cancer was admitted to our hospital. His liver function was impaired(total bilirubin 1.6mg/dL)with multiple liver metastases. He was treated with chemotherapy of S-1 plus cisplatin but it was discon- tinued due to severe diarrhea(CTCAE Grade 3)on day 6 and his liver dysfunction progressed(total bilirubin 10.3mg/dL). After his diarrhea improved, he was treated with capecitabine plus oxaliplatin(capecitabine 3,600mg/day on day 1-14, oxaliplatin 130mg/m2 on day 1, q3 weeks). His severe jaundice and general condition improved without severe non-hematological toxicity, and he was ultimately discharged. He achieved a partial response(RECIST v1.1)after capecitabine plus oxaliplatin treatment, and this therapy has been continued for 15 months. This case suggests that capecitabine plus oxaliplatin may be beneficial even in advanced gastric cancer patients with impaired liver function from multiple liver metastases.

[A case of postoperative recurrent hilar cholangiocarcinoma in the lower bile duct treated with pancreatoduodenectomy].

When surgery is selected to treat postoperative recurrent hilar cholangiocarcinoma in the intrapancreatic bile duct, attention should be paid to the following: 1 ) technical resectability of the lesion, 2) reconstruction, and 3) high risk of complications. Eight cases, including the present case, of pancreatoduodenectomy (PD) for postoperative recurrent hilar cholangiocarcinoma in the intrapancreatic bile duct have been reported thus far. In October 2009, a 73-year-old man noticed that his stools were gray and visited a physician. He was diagnosed with cholangiocarcinoma on close examination and underwent left hepatic and caudate lobectomy in January 2010. After the surgery, he was treated with TS-1 (80 mg) and followed up at the outpatient clinic of our hospital. In July 2013, he was diagnosed with cancer of the lower bile duct and was admitted for surgery. The first and second pathological findings were carcinoma of the bile duct and papillary adenocarcinoma, respectively. The findings from the immunostaining were also inconsistent. The histopathological examination result suggested multicentric recurrence. The surgery was highly invasive, increasing the patient's risk of complications, in addition to the presence of postoperative adhesion. Therefore, surgery may be an important option for cases of localized recurrence but not for multicentric recurrence.

The Efficacy and Safety of Nivolumab Plus mFOLFOX6 in Gastric Cancer with Severe Peritoneal Metastasis.

(1) Background: Nivolumab plus chemotherapy is established as a first-line treatment for advanced gastric cancer (AGC). While mFOLFOX6 is commonly used for AGC with severe peritoneal metastasis, the efficacy of nivolumab combined with it remains uncertain. We evaluated the outcomes of nivolumab plus mFOLFOX6 for AGC with severe peritoneal metastasis in clinical practice. (2) Methods: This multicenter retrospective study was conducted between December 2021 and June 2023. We investigated AGC patients with massive ascites or inadequate oral intake due to severe peritoneal metastasis and who received nivolumab plus mFOLFOX6. (3) Results: Among 106 patients treated with nivolumab plus chemotherapy, 21 (19.8%) had severe peritoneal metastasis, with 14 receiving nivolumab plus mFOLFOX6. The median progression-free survival was 7.4 months (95%CI 1.9-10.1), and the median overall survival was 10.7 months (95%CI 5.3-NA), with four patients (28.5%) surviving more than 12 months. Improved ascites and oral intake were observed in 6/14 patients (42.8%) and 10/11 patients (90.9%), respectively. The major grade 3 or more adverse events included leukopenia (28.5%) and neutropenia (21.4%), with no severe immune-related adverse events reported. (4) Conclusions: The safety and moderate efficacy of nivolumab plus mFOLFOX6 were suggested even in AGC patients with severe peritoneal metastasis.

Non-Markovian properties and multiscale hidden Markovian network buried in single molecule time series.

We present a novel scheme to extract a multiscale state space network (SSN) from single-molecule time series. The multiscale SSN is a type of hidden Markov model that takes into account both multiple states buried in the measurement and memory effects in the process of the observable whenever they exist. Most biological systems function in a nonstationary manner across multiple timescales. Combined with a recently established nonlinear time series analysis based on information theory, a simple scheme is proposed to deal with the properties of multiscale and nonstationarity for a discrete time series. We derived an explicit analytical expression of the autocorrelation function in terms of the SSN. To demonstrate the potential of our scheme, we investigated single-molecule time series of dissociation and association kinetics between epidermal growth factor receptor (EGFR) on the plasma membrane and its adaptor protein Ash/Grb2 (Grb2) in an in vitro reconstituted system. We found that our formula successfully reproduces their autocorrelation function for a wide range of timescales (up to 3 s), and the underlying SSNs change their topographical structure as a function of the timescale; while the corresponding SSN is simple at the short timescale (0.033-0.1 s), the SSN at the longer timescales (0.1 s to ~3 s) becomes rather complex in order to capture multiscale nonstationary kinetics emerging at longer timescales. It is also found that visiting the unbound form of the EGFR-Grb2 system approximately resets all information of history or memory of the process.

[Evaluation of usability of an anticancer drug after changing it to liquid formulation].

Although the advantages of a liquid formulation over a lyophilized one have been mentioned, few studies have quantified the differences between the two. For the purpose of clarifying the advantages of a liquid formulation, we carried out a comparison of ELPLAT I. V. INFUSION SOLUTION, which is a liquid formulation of oxaliplatin, and ELPLAT FOR INJECTION, which is a lyophilized formulation of oxaliplatin. Since multiple factors(such as skill in drug preparation and the dosage)as well as the formulation influenced the preparation time, each factor was assessed by a Latin square design. The mean preparation time was 62. 39 seconds for the liquid formulation and 171. 22 seconds for the lyophilized formulation, and a decrease of approximately two minutes(p<0. 0001)was observed with the liquid formulation. Furthermore, after linear regression analysis of multiple factors, shortening of the preparation time was found to be related to the liquid formulation. The preparation time was significantly shortened according to the level of skill in drug preparation with the liquid formulation, but not the lyophilized formulation. This was because the total preparation time was relatively long for the lyophilized formulation. Superior usability of liquid formulation was shown by our quantification of the advantages of liquid oxaliplatin.

Risk factors of heavy uterine bleeding in patients with endometriosis and adenomyosis treated with dienogest.

OBJECTIVE: Dienogest (DNG), a fourth-generation progestin, reduces pain associated with endometriosis and uterine adenomyosis; however, it is associated with irregular uterine bleeding that can cause anemia and poor quality of life. We investigated risk factors for heavy bleeding following DNG administration. MATERIALS AND METHODS: We retrospectively investigated patients who received DNG for risk factors of heavy uterine bleeding, including clinical diagnosis, use of pretreatment gonadotropin-releasing hormone agonist, smoking, cancer antigen 125, and blood hormone levels. We additionally assessed the uterine area in patients with uterine adenomyosis, the major axis of the uterine body, the major axis of myometrial thickness, the site of tumor development, and the site of myoma development in patients with uterine fibroids. RESULTS: Eighty Japanese patients were administered DNG. The median age was 41 (range: 24-51) years. The odds ratio (OR) for moderate-to-severe bleeding according to clinical diagnosis were 0.33 (P = 0.011) for endometrioma and 9.00 (P = 0.049) for uterine adenomyosis. Receiver operating characteristic curve analysis of the uterine area associated with uterine adenomyosis showed an area under the curve (AUC) of 0.909 between those with major and minor bleeding, with an optimal cut-off value of 7388.2 mm2. The uterine body major axis had an AUC of 0.946, with an optimal cut-off value of 78.3 mm. The major axis of myometrial thickness had an AUC of 0.855, with an optimal cut-off value of 46.8 mm. CONCLUSION: Patients with endometrioma treated with DNG were less likely to experience heavy uterine bleeding. Uterine bleeding in patients with uterine adenomyosis and adenomyosis associated with uterine fibroids should be closely monitored while administering DNG.

Chemical Peeling Therapy Using Phenol for the Cervico-Vaginal Intraepithelial Neoplasia.

Objective: This study aimed to validate the use of liquid phenol-based chemical peeling therapy for cervical and vaginal intraepithelial neoplasia (CIN and VaIN, respectively), with the goal of circumventing obstetric complications associated with surgical treatment and to determine the factors associated with treatment resistance. Methods: A total of 483 eligible women diagnosed with CIN, VaIN, or both, participated in this study. Participants underwent phenol-based chemical peeling therapy every 4 weeks until disease clearance. Disease clearance was determined by negative Pap tests for four consecutive weeks or by colposcopy. HPV genotyping was conducted at the onset of the study and after disease clearance in select cases. Our preliminary analysis compared the recurrence and persistence rates between 294 individuals who received phenol-based chemical peeling therapy and 189 untreated patients. Results: At 2 years following diagnosis, persistent disease was observed in 18%, 60%, and 88% of untreated patients with CIN1-3, respectively, and <2% of patients with CIN who received phenol-based chemical peeling therapy. Among 483 participants, 10 immune-suppressed patients required multiple treatments to achieve disease clearance, and 7 were diagnosed with cervical cancer. Of the 466 participants, except those with cancer or immune suppression, the number of treatment sessions until CIN/VaIN clearance ranged from 2 to 42 (average: 9.2 sessions). In total, 43 participants (9.2%) underwent surgical treatment. Six patients (1.3%) experienced recurrence of CIN2 or worse, suggesting that treatment failed in 46 patients (9.9%). No obstetrical complications were noted among the 98 pregnancies following this therapy. Factors associated with resistance to this therapy include immune suppression, ages 35-39 years, higher-grade lesions, and multiple HPV-type infections. Conclusions: Phenol-based therapy is safe and effective for CINs and VaINs. Women aged < 35 years and with persistent CIN1 or CIN2 with a single HPV-type infection are suitable candidates for phenol-based chemical peeling therapy. However, this therapy requires multiple lengthy sessions.

[Associations between Maternal Postpartum Depression and Psychosocial Factors Including Marital Relationship and Social Support].

OBJECTIVES: We aimed to investigate the psychosocial factors for postpartum depression as indicated by a high score of the Edinburgh Postnatal Depression Scale (EPDS), including marital relationship and social support. Relevant factors for antenatal depression were also analyzed. METHODS: Thirty-five wife-and-husband pairs who visited University Hospital A for the wife's antenatal health check-up participated in a questionnaire survey using the Japanese version of the EPDS. Social support from the wife's husband, kins, and others including friends at the third trimester of pregnancy and 1 month after birth was assessed. The Marital Love Scale (MLS) was also used, and two marital relationship questions were asked regarding the husband's and wife's considerate actions toward each other during pregnancy. Binary logistic regression analysis was conducted to determine adjusted associations between higher EPDS scores (≥5 for postpartum depression and ≥7 for antenatal depression) and indicators for social support and marital relationships. RESULTS: The most relevant factor for higher postpartum EPDS scores was a higher antenatal EPDS score, followed by the couple's poor communication skills (the wife did not feel any appreciation from her husband) during pregnancy and no support from the wife's husband during the postpartum period. The wife's poor marital communication skills and the husband's low MLS scores during pregnancy were associated (borderline significance) with the wife's higher antenatal EPDS scores. CONCLUSIONS: A good marital relationship before birth and support by the husband after birth may be important for preventing postpartum depression.

Immune responses against human papillomavirus (HPV) infection and evasion of host defense in cervical cancer.

Human papillomavirus (HPV) is the most important etiological factor for cervical cancer. A recent study demonstrated that more than 20 HPV types were thought to be oncogenic for uterine cervical cancer. Notably, more than one-half of women show cervical HPV infections soon after their sexual debut, and about 90 % of such infections are cleared within 3 years. Immunity against HPV might be important for elimination of the virus. The innate immune responses involving macrophages, natural killer cells, and natural killer T cells may play a role in the first line of defense against HPV infection. In the second line of defense, adaptive immunity via cytotoxic T lymphocytes (CTLs) targeting HPV16 E2 and E6 proteins appears to eliminate cells infected with HPV16. However, HPV can evade host immune responses. First, HPV does not kill host cells during viral replication and therefore neither presents viral antigen nor induces inflammation. HPV16 E6 and E7 proteins downregulate the expression of type-1 interferons (IFNs) in host cells. The lack of co-stimulatory signals by inflammatory cytokines including IFNs during antigen recognition may induce immune tolerance rather than the appropriate responses. Moreover, HPV16 E5 protein downregulates the expression of HLA-class 1, and it facilitates evasion of CTL attack. These mechanisms of immune evasion may eventually support the establishment of persistent HPV infection, leading to the induction of cervical cancer. Considering such immunological events, prophylactic HPV16 and 18 vaccine appears to be the best way to prevent cervical cancer in women who are immunized in adolescence.

Switching direction in electric-signal-induced cell migration by cyclic guanosine monophosphate and phosphatidylinositol signaling.

Switching between attractive and repulsive migration in cell movement in response to extracellular guidance cues has been found in various cell types and is an important cellular function for translocation during cellular and developmental processes. Here we show that the preferential direction of migration during electrotaxis in Dictyostelium cells can be reversed by genetically modulating both guanylyl cyclases (GCases) and the cyclic guanosine monophosphate (cGMP)-binding protein C (GbpC) in combination with the inhibition of phosphatidylinositol-3-OH kinases (PI3Ks). The PI3K-dependent pathway is involved in cathode-directed migration under a direct-current electric field. The catalytic domains of soluble GCase (sGC) and GbpC also mediate cathode-directed signaling via cGMP, whereas the N-terminal domain of sGC mediates anode-directed signaling in conjunction with both the inhibition of PI3Ks and cGMP production. These observations provide an identification of the genes required for directional switching in electrotaxis and suggest that a parallel processing of electric signals, in which multiple-signaling pathways act to bias cell movement toward the cathode or anode, is used to determine the direction of migration.

Determination of human papillomavirus type in archival tissue specimens of invasive cervical cancer using molecular mapping and E6/E7-based polymerase chain reaction.

In our previous study, an L1-based human papillomavirus (HPV) test using liquid-based cytology revealed that some invasive cervical cancers (ICC) exhibited multiple HPV types or harbored no HPV DNA. Here, molecular mapping of formalin-fixed paraffin-embedded cancer tissue specimens from the same patients were conducted to confirm these observations. Among 377 ICC cases, 73 eligible specimens (9 positive for multiple HPV types, 16 negative for HPV, and 48 positive for a single HPV type from the previous study) were reexamined by manual microdissection of cancer lesions, then subjected to HPV genotyping using the uniplex E6/E7 polymerase-chain-reaction method to detect all high-risk and potentially high-risk HPV types. The HPV typing results were confirmed in 52 of 73 cancer cases; among the 21 remaining cases, 15 were discordant and 6 were partially concordant. In total, 8 of 16 (50%) HPV-negative samples became positive; 6 were positive for HPV16 and 2 were positive for HPV67. Moreover, two samples previously positive for HPV6 and HPV53 were negative for HPV. All nine cancers with multiple HPV types were found to harbor only a single HPV type. In total, 63 cancer tissues exhibited a single HPV type. HPV16 and HPV18 were detected in squamous cell carcinoma (SCC) and adenocarcinoma (ADC). Alpha-5 (HPV82), -6 (HPV56), and -9 (HPV31/52/67) HPV types were detected in SCC, whereas Alpha-7 (HPV59/68) types were detected in ADC and adenosquamous carcinoma (ADSCC). These findings suggested that the different HPV types induced different histological cancers. Furthermore, all SCCs and 10 of 11 usual-type ADCs were positive for high-risk HPV types, supporting the use of HPV screening for the detection of these cancers and associated premalignant lesions. HPV16 is likely to remain undetected in some cervical cancer tissues because of low viral-copy-numbers. Putative high-risk HPV types (e.g., HPV67 and HPV82) might be high risk in Japan.

"Quenchbodies": quench-based antibody probes that show antigen-dependent fluorescence.

Here, we describe a novel reagentless fluorescent biosensor strategy based on the antigen-dependent removal of a quenching effect on a fluorophore attached to antibody domains. Using a cell-free translation-mediated position-specific protein labeling system, we found that an antibody single chain variable region (scFv) that had been fluorolabeled at the N-terminal region showed a significant antigen-dependent fluorescence enhancement. Investigation of the enhancement mechanism by mutagenesis of the carboxytetramethylrhodamine (TAMRA)-labeled anti-osteocalcin scFv showed that antigen-dependency was dependent on semiconserved tryptophan residues near the V(H)/V(L) interface. This suggested that the binding of the antigen led to the interruption of a quenching effect caused by the proximity of tryptophan residues to the linker-tagged fluorophore. Using TAMRA-scFv, many targets including peptides, proteins, and haptens including morphine-related drugs could be quantified. Similar or higher sensitivities to those observed in competitive ELISA were obtained, even in human plasma. Because of its versatility, this "quenchbody" is expected to have a range of applications, from in vitro diagnostics, to imaging of various targets in situ.

Multiple-state reactions between the epidermal growth factor receptor and Grb2 as observed by using single-molecule analysis.

Phosphorylation of the cytoplasmic tyrosine residues of the epidermal growth factor receptor (EGFR) upon binding of EGF induces recognition of various intracellular signaling molecules, including Grb2. Here, the reaction kinetics between EGFR and Grb2 was analyzed by visualizing single molecules of Grb2 conjugated to the fluorophore Cy3 (Cy3-Grb2). The plasma membrane fraction was purified from human epithelial carcinoma A431 cells after stimulation with EGF and attached to coverslips. Unitary events of association and dissociation of Cy3-Grb2 on the EGFR in the membrane fraction were observed at different concentrations of Grb2 (0.1-100 nM). The dissociation kinetics could be explained by using a multiple-exponential function with a major (>90%) dissociation rate of 8 s(-1) and a few minor components, suggesting the presence of multiple bound states. In contrast, the association kinetics could be described by a stretched exponential function, suggesting the presence of multiple reaction channels from many unbound substates. Transitions between the unbound substates were also suggested. Unexpectedly, the rate of association was not proportional to the Grb2 concentration: an increase in Cy3-Grb2 concentration by a factor of 10 induced an increase in the reaction frequency approximately by a factor of three. This effect can compensate for fluctuation of the signal transduction from EGFR to Grb2 caused by variations in the expression level of Grb2 in living cells.

C. elegans episodic swimming is driven by multifractal kinetics.

Fractal scaling is a common property of temporal change in various modes of animal behavior. The molecular mechanisms of fractal scaling in animal behaviors remain largely unexplored. The nematode C. elegans alternates between swimming and resting states in a liquid solution. Here, we report that C. elegans episodic swimming is characterized by scale-free kinetics with long-range temporal correlation and local temporal clusterization, namely consistent with multifractal kinetics. Residence times in actively-moving and inactive states were distributed in a power law-based scale-free manner. Multifractal analysis showed that temporal correlation and temporal clusterization were distinct between the actively-moving state and the inactive state. These results indicate that C. elegans episodic swimming is driven by transition between two behavioral states, in which each of two transition kinetics follows distinct multifractal kinetics. We found that a conserved behavioral modulator, cyclic GMP dependent kinase (PKG) may regulate the multifractal kinetics underlying an animal behavior. Our combinatorial analysis approach involving molecular genetics and kinetics provides a platform for the molecular dissection of the fractal nature of physiological and behavioral phenomena.

[The actual conditions and problems of terminal home nursing care at our hospital].

In 2006, we reconfirmed Suwachuo hospital slogan as "When there is a need of community, we will do our best to meet it" and the department of home nursing care is officially established in our hospital next spring. A death rate at home is generally used to evaluate a home nursing care, and this rate at our department was 60.8% in 2008. However, community needs various options in addition to death at home. Keeping an eye on community opinions is of great importance.

Quantitative Studies for Cell-Division Cycle Control.

The cell-division cycle (CDC) is driven by cyclin-dependent kinases (CDKs). Mathematical models based on molecular networks, as revealed by molecular and genetic studies, have reproduced the oscillatory behavior of CDK activity. Thus, one basic system for representing the CDC is a biochemical oscillator (CDK oscillator). However, genetically clonal cells divide with marked variability in their total duration of a single CDC round, exhibiting non-Gaussian statistical distributions. Therefore, the CDK oscillator model does not account for the statistical nature of cell-cycle control. Herein, we review quantitative studies of the statistical properties of the CDC. Over the past 70 years, studies have shown that the CDC is driven by a cluster of molecular oscillators. The CDK oscillator is coupled to transcriptional and mitochondrial metabolic oscillators, which cause deterministic chaotic dynamics for the CDC. Recent studies in animal embryos have raised the possibility that the dynamics of molecular oscillators underlying CDC control are affected by allometric volume scaling among the cellular compartments. Considering these studies, we discuss the idea that a cluster of molecular oscillators embedded in different cellular compartments coordinates cellular physiology and geometry for successful cell divisions.