Higher oxytocin concentrations occur in subjects who build affiliative relationships with companion robots

Building affiliative relationships with others is important for mental health. Recently, robots have been expected to play a role in improving mental health, but there is little scientific evidence as to whether they can build affiliative relationships with humans. To investigate that, we conducted studies combining behavior, physiology and questionnaires for companion robot Owners and Non-Owners. The results reveal that the steady-state concentration of oxytocin, a hormone related to affiliative relationships, was significantly higher in Owners than in Non-Owners. In addition, the Owners showed more behaviors indicative of intimacy than the Non-Owners. These results suggest that humans can build affiliative relationships with robots. Fifteen minutes of contact with the robot decreased the concentration of cortisol in both groups, suggesting that even a brief contact can contribute to improving mental health. Therefore, relationships between humans and robots may be one option to improve mental health and enhance well-being.

Inhibitory effect of polysulfide, an endogenous sulfur compound, on oxidative stress-induced TRPA1 activation

Polysulfide (PS), an endogenous sulfur compound, generated by oxidation of hydrogen sulfide, has a stimulatory action on the nociceptive TRPA1 channel. TRPA1 is also activated by reactive oxygen species such as hydrogen peroxide (H₂O₂) produced during inflammation. Here, we examined the effect of PS on H₂O₂-induced responses in native and heterologously expressed TRPA1 using a cell-based calcium assay. We also carried out behavioral experiments in vivo. In mouse sensory neurons, H₂O₂ elicited early TRPA1-dependent and late TRPA1-independent increases of [Ca²⁺]_i. The former was suppressed by the pretreatment with PS. In cells heterologously expressed TRPA1, PS suppressed [Ca²⁺]_i responses to H₂O₂. Simultaneous measurement of [Ca²⁺]_i and the intracellular PS level revealed that scavenging effect of PS was not related to the inhibitory effect. Removal of extracellular Ca²⁺, a calmodulin inhibitor and dithiothreitol attenuated the inhibitory effect of PS. Pretreatment with PS diminished nociceptive behaviors induced by H₂O₂. The present data suggest that PS suppresses oxidative stress-induced TRPA1 activation due to cysteine modification and Ca²⁺/calmodulin signaling. Thus, endogenous sulfurs may have regulatory roles in nociception via functional changes in TRPA1 under inflammatory conditions.

Post-weaning stroking stimuli induce affiliative behavior toward humans and influence brain activity in female rats

Gentle touch contributes to affiliative interactions. We investigated the effects of gentle stroking in female rats on the development of affiliative behaviors toward humans and we exploratively examined brain regions in which activity was influenced by stroking. Rats that had received stroking stimuli repeatedly after weaning emitted 50-kHz calls, an index of positive emotion, and showed affiliative behaviors toward the experimenter. Hypothalamic paraventricular oxytocin neurons were activated in the rats after stroking. The septohypothalamic nucleus (SHy) in the post-weaningly stroked rats showed decreased activity in response to stroking stimuli compared with that in the non-stroked control group. There were negative correlations of neural activity in hypothalamic regions including the SHy with the number of 50-kHz calls. These findings revealed that post-weaning stroking induces an affiliative relationship between female rats and humans, possibly via activation of oxytocin neurons and suppression of the activity of hypothalamic neurons.

Gentle stroking stimuli induce affiliative responsiveness to humans in male rats

Gentle tactile stimuli have been shown to play an important role in the establishment and maintenance of affiliative social interactions. Oxytocin has also been shown to have similar actions. We investigated the effects of gentle stroking on affiliative relationships between humans and rats and the effects of gentle stroking on activation of oxytocin neurons. Male rats received 5-min stroking stimuli from an experimenter every other day for 4 weeks between 3 and 6 weeks of age (S3–6 group), for 4 weeks between 7 and 10 weeks of age (S7–10 group), or for 8 weeks between 3 and 10 weeks of age (S3–10 group). Control rats did not receive stroking stimuli. Rats in the S7–10 and S3–10 groups emitted 50-kHz calls, an index of positive emotion, more frequently during stroking stimuli. Rats in the S3–6, S7–10, and S3–10 groups showed affiliative behaviors toward the experimenter. Oxytocin neurons in the hypothalamic paraventricular nucleus of rats in the S3–6, S7–10, and S3–10 groups were activated following stroking stimuli. These findings revealed that post-weaning repeated stroking stimuli induce an affiliative relationship between rats and humans and activation of oxytocin neurons.

USVSEG: A robust method for segmentation of ultrasonic vocalizations in rodents

Rodents' ultrasonic vocalizations (USVs) provide useful information for assessing their social behaviors. Despite previous efforts in classifying subcategories of time-frequency patterns of USV syllables to study their functional relevance, methods for detecting vocal elements from continuously recorded data have remained sub-optimal. Here, we propose a novel procedure for detecting USV segments in continuous sound data containing background noise recorded during the observation of social behavior. The proposed procedure utilizes a stable version of the sound spectrogram and additional signal processing for better separation of vocal signals by reducing the variation of the background noise. Our procedure also provides precise time tracking of spectral peaks within each syllable. We demonstrated that this procedure can be applied to a variety of USVs obtained from several rodent species. Performance tests showed this method had greater accuracy in detecting USV syllables than conventional detection methods.

Selection of cellular genetic markers for the detection of infectious poliovirus

AIMS

Cellular responses of an established cell line from human intestinal epithelial cells (INT-407 cells) against poliovirus (PV) infections were investigated in order to find cellular genetic markers for infectious PV detection.

METHODS AND RESULTS

Gene expression profile of INT-407 cells was analysed by DNA microarray technique when cells were infected with poliovirus 1 (PV1) (sabin) at multiplicity of infection of 10^-3 and incubated for 12 h. Poliovirus infection significantly altered the gene expressions of two ion channels, KCNJ4 and SCN7A. The expression profile of KCNJ4 gene was further investigated by real-time RT-qPCR, and it was found that KCNJ4 gene was significantly regulated at 24 h postinfection of PV1.

CONCLUSIONS

KCNJ4 gene, coding a potassium channel protein, is proposed as a cellular genetic marker for infectious PV detection.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first study to show the availability of cellular responses to detect infectious PV. The selection of cellular genetic markers for infectious viruses using DNA microarray and RT-qPCR can be applicable for the other enteric viruses.

Pup exposure facilitates retrieving behavior via the oxytocin neural system in female mice

Parental behavior in mammals is innate, but it is also facilitated by social experience, specifically social interactions between the parent and infant. Social interactions with infants also induce the alloparental behavior of virgin animals. Oxytocin (OT) plays an important role in mediating alloparental behavior. Although parental behavior is modulated by the medial preoptic area (MPOA) and adjacent regions, it is unclear how OT acts in these regions as a control mechanism of alloparental behavior promoted by adult-pup interaction. The aim of this study was to investigate the role of OT for facilitating effects of adult-pup interactions on alloparental behavior via neural activity of preoptic area (POA), including MPOA and adjacent area. For this purpose, we conducted behavioral tests and examined the neural activity of the OT system in POA. Virgin female mice that were repeatedly exposed to pups showed shorter retrieving latencies and higher number of c-Fos expressing neurons in POA, particular in lateral preoptic area (LPO) compared to control animals that were exposed to pups only one time. In addition, repeated pup exposure increased the proportion of OT neurons and OTR neurons expressing c-Fos in POA. The concentration of OT also significantly increased in the POA. Finally, infusion of an OT antagonist into the POA area blocked the facilitating effects of repeated pup exposure on retrieving behavior. These results demonstrated that the facilitating effects of repeated pup exposure on alloparental behavior occurred via an organizational role of the OT system.

Structure and function of neonatal social communication in a genetic mouse model of autism

A critical step toward understanding autism spectrum disorder (ASD) is to identify both genetic and environmental risk factors. A number of rare copy number variants (CNVs) have emerged as robust genetic risk factors for ASD, but not all CNV carriers exhibit ASD and the severity of ASD symptoms varies among CNV carriers. Although evidence exists that various environmental factors modulate symptomatic severity, the precise mechanisms by which these factors determine the ultimate severity of ASD are still poorly understood. Here, using a mouse heterozygous for Tbx1 (a gene encoded in 22q11.2 CNV), we demonstrate that a genetically triggered neonatal phenotype in vocalization generates a negative environmental loop in pup-mother social communication. Wild-type pups used individually diverse sequences of simple and complicated call types, but heterozygous pups used individually invariable call sequences with less complicated call types. When played back, representative wild-type call sequences elicited maternal approach, but heterozygous call sequences were ineffective. When the representative wild-type call sequences were randomized, they were ineffective in eliciting vigorous maternal approach behavior. These data demonstrate that an ASD risk gene alters the neonatal call sequence of its carriers and this pup phenotype in turn diminishes maternal care through atypical social communication. Thus, an ASD risk gene induces, through atypical neonatal call sequences, less than optimal maternal care as a negative neonatal environmental factor.

Bayesian modeling of virus removal efficiency in wastewater treatment processes

Left-censored datasets of virus density in wastewater samples make it difficult to evaluate the virus removal efficiency in wastewater treatment processes. In the present study, we modeled the probabilistic distribution of virus removal efficiency in a wastewater treatment process with a Bayesian approach, and investigated how many detect samples in influent and effluent are necessary for accurate estimation. One hundred left-censored data of virus density in wastewater (influent and effluent) were artificially generated based on assumed log-normal distributions and the posterior predictive distribution of virus density, and the log-ratio distribution were estimated. The estimation accuracy of distributions was quantified by Bhattacharyya coefficient. When it is assumed that the accurate estimation of posterior predictive distributions is possible when a 100% positive rate is obtained for 12 pairs of influent and effluent, 11 out of 144, 60 out of 324, and 201 out of 576 combinations of detect samples gave an accurate estimation at the significant level of 0.01 in a Kruskal-Wallis test when the total sample number was 12, 18, and 24, respectively. The combinations with the minimum number of detect samples were (12, 9), (16, 10), and (21, 8) when the total sample number was 12, 18, and 24, respectively.

Developmental social environment imprints female preference for male song in mice

Background

Sexual imprinting is important for kin recognition and for promoting outbreeding, and has been a driving force for evolution; however, little is known about sexual imprinting by auditory cues in mammals. Male mice emit song-like ultrasonic vocalizations that possess strain-specific characteristics.

Objectives

In this study, we asked whether female mice imprint and prefer specific characteristics in male songs.

Methods and Findings

We used the two-choice test to determine the song preference of female C57BL/6 and BALB/c mice. By assessing the time engaged in searching behavior towards songs played back to females, we found that female mice displayed an innate preference for the songs of males from different strains. Moreover, this song preference was regulated by female reproductive status and by male sexual cues such as the pheromone ESP1. Finally, we revealed that this preference was reversed by cross-fostering and disappeared under fatherless conditions, indicating that the behavior was learned by exposure to the father's song.

Conclusions

Our results suggest that female mice can discriminate among male song characteristics and prefer songs of mice from strains that are different from their parents, and that these preferences are based on their early social experiences. This is the first study in mammals to demonstrate that male songs contribute to kin recognition and mate choice by females, thus helping to avoid inbreeding and to facilitate offspring heterozygosity.

Source identification of nitrous oxide on autotrophic partial nitrification in a granular sludge reactor

Emission of nitrous oxide (N2O) during biological wastewater treatment is of growing concern since N2O is a major stratospheric ozone-depleting substance and an important greenhouse gas. The emission of N2O from a lab-scale granular sequencing batch reactor (SBR) for partial nitrification (PN) treating synthetic wastewater without organic carbon was therefore determined in this study, because PN process is known to produce more N2O than conventional nitrification processes. The average N2O emission rate from the SBR was 0.32 ± 0.17 mg-N L(-1) h(-1), corresponding to the average emission of N2O of 0.8 ± 0.4% of the incoming nitrogen load (1.5 ± 0.8% of the converted NH4(+)). Analysis of dynamic concentration profiles during one cycle of the SBR operation demonstrated that N2O concentration in off-gas was the highest just after starting aeration whereas N2O concentration in effluent was gradually increased in the initial 40 min of the aeration period and was decreased thereafter. Isotopomer analysis was conducted to identify the main N2O production pathway in the reactor during one cycle. The hydroxylamine (NH2OH) oxidation pathway accounted for 65% of the total N2O production in the initial phase during one cycle, whereas contribution of the NO2(-) reduction pathway to N2O production was comparable with that of the NH2OH oxidation pathway in the latter phase. In addition, spatial distributions of bacteria and their activities in single microbial granules taken from the reactor were determined with microsensors and by in situ hybridization. Partial nitrification occurred mainly in the oxic surface layer of the granules and ammonia-oxidizing bacteria were abundant in this layer. N2O production was also found mainly in the oxic surface layer. Based on these results, although N2O was produced mainly via NH2OH oxidation pathway in the autotrophic partial nitrification reactor, N2O production mechanisms were complex and could involve multiple N2O production pathways.

Transport Response is a filial-specific behavioral response to maternal carrying in C57BL/6 mice

Background

A mother carries her young in many altricial mammals, such as cats, lions, rats and mice. During maternal carrying, the transported young assume a compact posture. We have recently shown that, in both humans and mice, the carried infants immediately calmed down and showed reductions in heart rate, distress vocalizations, and voluntary movement. The loss of the calming response in mouse pups hindered maternal retrieval efficacy. These findings suggested that the infant calming response functioned to reduce the maternal burden of carrying and was therefore conserved in a variety of mammalian species. However, it remains unclear how and when each component of this calming response develops and whether it is a filial-specific behavior.

Results

We dissected various components of the carrying-induced responses in mouse pups, collectively called the “Transport Response” herein. We showed that during the second postnatal week, pups exhibited characteristic compact posture with limb ventroflexion. The body trunk remained paradoxically pliable, suggesting complex neural regulation throughout the body. Pups also showed an increased pain tolerance to a tail pinch during the Transport Response. Analyses of the developmental courses of distinct components of the Transport Response revealed the independent regulation of each component: in the first postnatal week, the cessation of ultrasonic vocalizations was exhibited prominently; in the second postnatal week, immobilization reached its peak; and toward the third postnatal week, the postural component became fully matured. At the end of the third postnatal week, when the pups are able to transport by themselves, the pups no longer exhibited the Transport Response.

Conclusions

This study has revealed the mouse Transport Response as a complex set of behavioral and physiological components, each of which has a specific postnatal time window but is orchestrated in a well-matched manner with the maturation of ambulatory ability in the pups. These findings collectively indicate that the Transport Response is a filial-specific, innate behavioral reaction and is distinct from a simple reflex or defensive freezing response. The Transport Response could be a novel index of primitive filial attachment behaviors, acting to smooth mother-infant interaction.

Introduction of a degassing membrane technology into anaerobic wastewater treatment

The effectiveness of degasification using a degassing membrane to improve chemical oxygen demand (COD) removal efficiency was investigated using a bench-scale upflow anaerobic sludge blanket (UASB) reactor. Vacuum degasification was able to transfer dissolved gas in the bulk liquid of the UASB reactor inside the membrane. Such a process might provide thermodynamically favorable conditions for the degradation of organic compounds. The COD-removal efficiency improved from 83% during normal operation to 90% during the degassing operation.

Mandibular reconstruction using a poly(L-lactide) mesh combined with autogenous particulate cancellous bone and marrow: a prospective clinical study

The purpose of this study was to evaluate the stability and viability of mandibular bone regeneration using a poly(L-lactide) (PLLA) mesh and autogenous particulate cancellous bone and marrow (PCBM). Sixty-two procedures were undertaken at eight hospitals (22 malignant tumours, 30 benign tumours, five cysts, two osteomyelitis, two trauma, and one atrophy of the alveolar ridge); the success rate was 84%. The follow-up period was between 9 and 200 months (mean 88.2 months). Consequently, bone regeneration at 6 months postoperation was excellent in 35 cases (57%), good in 17 cases (27%), and poor in 10 cases (16%). In six of the 'poor' cases, the PLLA mesh was removed due to local infection early after surgery. Bone resorption>20% was observed in only one of 46 cases with a follow-up term of >1 year. There were no signs of any other adverse effects except in one case where a section of the tray broke off late in the follow-up period. It is concluded that this method is stable and effective due to favourable morphological and functional recovery and low invasiveness. It may thus be a useful alternative procedure for mandibular reconstruction.

Importance of mother-infant communication for social bond formation in mammals

Mother-infant bonding is a universal relationship of all mammalian species. Here, we describe the role of reciprocal communication between mother and infant in the formation of bonding for several mammalian species. Mother-infant bond formation is reinforced by various social cues or stimuli, including communicative signals, such as odor and vocalizations, or tactile stimuli. The mother also develops cross-modal sensory recognition of the infant, during bond formation. Many studies have indicated that the oxytocin neural system plays a pivotal role in bond formation by the mother; however, the underlying neural mechanisms for infants have not yet been clarified. The comparative understanding of cognitive functions of mother and infants may help us understand the biological significance of mother-infant communication in mammalian species.

Oxytocin and mutual communication in mother-infant bonding

Mother-infant bonding is universal to all mammalian species. In this review, we describe the manner in which reciprocal communication between the mother and infant leads to mother-infant bonding in rodents. In rats and mice, mother-infant bond formation is reinforced by various social stimuli, such as tactile stimuli and ultrasonic vocalizations (USVs) from the pups to the mother, and feeding and tactile stimulation from the mother to the pups. Some evidence suggests that mother and infant can develop a cross-modal sensory recognition of their counterpart during this bonding process. Neurochemically, oxytocin in the neural system plays a pivotal role in each side of the mother-infant bonding process, although the mechanisms underlying bond formation in the brains of infants has not yet been clarified. Impairment of mother-infant bonding, that is, deprivation of social stimuli from the mother, strongly influences offspring sociality, including maternal behavior toward their own offspring in their adulthood, implying a "non-genomic transmission of maternal environment," even in rodents. The comparative understanding of cognitive functions between mother and infants, and the biological mechanisms involved in mother-infant bonding may help us understand psychiatric disorders associated with mother-infant relationships.

Characterization of microbial community structures and their activities in single anaerobic granules by beta imaging, microsensors and fluorescence in situ hybridization

The spatial distribution of microorganisms and their in situ activities in anaerobic granules were investigated by fluorescence in situ hybridization (FISH), beta imaging and microsensors. FISH results revealed a layered structure of microorganisms in the granule, where Chloroflexi was present in the outermost layer, Smithella spp. and Syntrophobacter spp. were found in a depth of ca. 100 μm, and Archaea was restricted to the inner layer (below ca. 300 μm from the surface). Substrate uptake patterns elucidated by beta imaging demonstrated that glucose uptake was highest at 50 μm depth, whereas propionate uptake had a peak at 200 μm depth. In addition, microsensor measurements revealed that acid was produced mainly at 100 μm depth and H(2) production was detected at a depth from 100 to 200 μm. H(2) consumption and corresponding CH(4) production were found below 200 μm from the surface. Direct comparison of these results implied sequential degradation of complex organic compounds in anaerobic granules; Chloroflexi contributed to fermentation of organic compounds and acid production in the outermost layer, volatile fatty acids were oxidized and H(2) was produced mainly by Smithella spp. and Syntrophobacter spp. at a depth from 100 to 200 μm, and Archaea produced CH(4) below ca. 300 μm from the surface.

Aspirin's ability to induce intestinal injury in rats is dependent on bile and can be reversed if pre-associated with phosphatidylcholine

Clinical evidence suggests that aspirin and particularly enteric-coated aspirin induce significant injury to the lower gut. We have reported that NSAID injury to the small bowel is exacerbated by bile acids and that phosphatidylcholine (PC) can protect against this damage. Using a recently described method, we intra-duodenally administered either: saline, aspirin or aspirin pre-associated with PC. The rats were euthanized 90 minutes later at which time we assessed: tissue injury morphologically, vascular permeability with i.v. administered Evan's blue and intestinal bleeding by measuring luminal hemoglobin. In a separate experiment, aspirin-induced injury was studied in rats whose bile duct was ligated either alone or in the presence of rat bile (collected from donor animals). Intra-duodenal administration of aspirin induced mucosal injury (observed histologically), an increase in vascular permeability and blood loss into the intestinal lumen, all of which could be attenuated if the NSAID was pre-associated with PC. Furthermore, using 100 mg/kg dose of aspirin it was determined that bile duct ligation (BDL) significantly reduced aspirin-induced intestinal bleeding which was not different from control rats. Lastly, it was determined that intestinal bleeding was significantly increased in rats with BDL if the aspirin was administered in rodent bile. Aspirin-induced intestinal injury and bleeding in the rat is dependent on the presence of luminal bile, which is likely attributable to it's constituent bile acids. Pre-association of aspirin with PC provides a novel therapeutic approach to significantly reduce aspirin-induced small intestinal injury and bleeding, as may occur with enteric-coated aspirin.

A role for strain differences in waveforms of ultrasonic vocalizations during male-female interaction

Male mice emit ultrasonic vocalizations (USVs) towards females during male-female interaction. It has been reported that USVs of adult male mice have the capability of attracting females. Although the waveform pattern of USVs is affected by genetic background, differences among strains with respect to USV and the effects of these differences on courtship behavior have not been analyzed fully. We analyzed USV patterns, as well as actual social behavior during USV recording, in 13 inbred mouse strains, which included laboratory and wild-derived strains. Significant effects of strain were observed for the frequency of USV emission, duration, and frequency of the waveform category. Principal component (PC) analysis showed that PC1 was related to frequency and duration, and PC2-4 were related to each waveform. In the comparison of USV patterns and behaviors among strains, wild-derived KJR mice displayed the highest scores for PC2-4, and female mice paired with KJR males did not emit rejection-related click sounds. It is assumed that the waveforms emitted by KJR males have a positive effect in male-female interaction. Therefore, we extracted waveforms in PC2-4 from the USV recordings of KJR mice to produce a sound file, "HIGH2-4". As a negative control, another sound file ("LOW2-4") was created by extracting waveforms in PC2-4 from strains with low scores for these components. In the playback experiments using these sound files, female mice were attracted to the speaker that played HIGH2-4 but not the speaker that played LOW2-4. These results highlight the role of strain differences in the waveforms of male USVs during male-female interaction. The results indicated that female mice use male USVs as information when selecting a suitable mate.

Triad stimulation frequency for cortical facilitation in cortical myoclonus

BACKGROUND

Abnormally enhanced cortical rhythmic activities have been reported in patients with cortical myoclonus. We recently reported a new triad-conditioning transcranial magnetic stimulation (TMS) method to detect the intrinsic rhythms of the primary motor cortex (M1). Triad-conditioning TMS revealed a 40-Hz intrinsic rhythm of M1 in normal subjects. In this investigation, we study the motor cortical facilitation induced by rhythmic triple TMS pulses (triad-conditioning TMS) in patients with cortical myoclonus.

METHODS

Subjects were 7 patients with cortical myoclonus (28-74 years old) and 13 healthy volunteers (30-71 years old). Three conditioning stimuli over M1 at the intensity of 110% active motor threshold preceded the test TMS at various interstimulus intervals corresponding to 10-200 Hz. The resulting amplitudes of conditioned motor evoked potentials recorded from the contralateral hand muscle were compared with those evoked by the test stimulus alone.

RESULTS

The facilitation at 25 ms (40 Hz) observed in normal subjects was absent in patients with cortical myoclonus. Instead, triad-conditioning TMS induced facilitation at a 40 ms interval (25 Hz) in cortical myoclonus.

DISCUSSIONS

This change in the timing of facilitation may be explained by a shift of the most preferential intrinsic rhythm of M1, or by some dysfunction in the interneuronal network in cortical myoclonus.

The effects of social experience and gonadal hormones on retrieving behavior of mice and their responses to pup ultrasonic vocalizations

Pup ultrasonic vocalizations (USVs) are emitted from maternally separated pups and are thought to be a trigger for eliciting maternal behavior in mice. We investigated the effects of social experience and gonadectomy on the retrieving behavior of mice and their responses to pup USVs produced by a nanocrystalline silicon thermo-acoustic emitter. In each experiment, virgin, gonadectomized, sham-operated, sexually experienced, and parenting mice of both sexes were used, and the effects of these manipulations were compared in each sex. The retrieving behavior of both sexes increased with social experience or gonadectomy. In particular, mothers showed the highest retrieving activity among female groups, while castrated male mice showed the highest retrieving activity among male groups. All groups of female mice responded to pup USVs, with the responsiveness of sexually experienced female mice being the most enhanced. Unlike the females, virgin male mice did not respond to pup USVs, although socially experienced or castrated males showed this response; fathers exhibited the highest responsiveness. These results suggest that not only parenting experience, but also mating experience, may enhance retrieving activity and response to pup USVs in mice of both sexes. Nevertheless, the degree to which parenting experience contributed to the enhancement of both activities differed between the sexes. Furthermore, gonadectomy enhanced both activities in both sexes, although its effect was more prominent in males. Overall, our findings suggest that alteration in responsiveness of mice to pup USVs might be one of the changes in parental behavior caused by social experiences or gonadal hormones.

Qualitative and quantitative estimation of host-specific fecal pollution using Bacteroides-Prevotella 16S rRNA genetic markers by T-RFLP and real-time PCR analyses

Rapid and reliable determination of the non-point sources of fecal pollution is a critical issue for the environmental microbiologists all over the world. In this work we evaluated the use of anaerobic bacterial group Bacteroides-Prevotella as an alternative fecal pollution indicator. Terminal restriction fragment length polymorphism (T-RFLP) and real-time polymerase chain reaction (RT-PCR) analyses were used to monitor and quantify human-, cow- and pig-specific fecal contamination in natural river waters. We also included DNA sequence analysis of the identified fecal markers revealed by T-RFLP in order to clarify the specificity of each marker. It was suggested that the most influent peaks for each fecal source could be used to identify the source of fecal pollution. Development of specific probes based on these markers permit to quantify source of contamination by quantitative RT-PCR. Therefore, we combined the T-RFLP results and RT-PCR assay to quantify fecal contamination by certain host. We can conclude that T-RFLP and RT-PCR analyses showed high reproducibility and sensitivity during analyzing real water samples and can be used to identify, track and quantify host-specific bacterial genetic markers in complex natural water environments.

Differentiation of embryonic stem cells

Embryonic stem (ES) cells are pluripotent cells whose developmental state is equivalent to cells of the inner cell mass in the blastocyst-stage embryo. This unit presents a method of producing differentiated ES cells in which the cells are first aggregated on a less adhesive surface to form embryoid bodies (EBs). EBs are allowed to attach to a permissive substrate and then differentiate into neural cells in a serum-free medium. The resulting cell population can be maintained for several passages in serum-free medium in the presence of basic fibroblast growth factor (bFGF) or allowed to differentiate into postmitotic neurons by plating onto a glial monolayer followed by culture with serum. Also included in the unit are procedures for preparing feeder cells from embryonic fibroblasts and for preparing glial monolayer cultures, both for use in the main ES production protocol.

Bacterial community dynamics and conversion of inorganic nitrogen under aerobic and micro-aerobic conditions

To investigate the inorganic nitrogen conversion in reactors that were operated under aerobic and micro-aerobic conditions and to identify populations that became acclimated in the reactors under those oxygen conditions, we operated two reactors with 72 h of hydraulic retention time and an artificial medium containing ammonium- and nitrite-nitrogen without any organic compound. We determined the concentration of inorganic nitrogen in samples from the reactors and the microbial community structure in the reactors by using PCR-DGGE of the partial 16S rRNA gene. The results showed that nitrification to nitrate fully progressed in the aerobic reactor within 24 h, but we could not find any obvious reaction in the micro-aerobic reactor. In a view of microbial community structure, the total number of microorganisms composing the communities in the reactors was dramatically decreased compared to those of the initial inoculated sludge that originated from the Jang-lim sewage treatment plant in Busan, Republic of Korea because of the limited nutrients present. One Nitrospira sp. was clearly detected under both aerobic (as DO > 2 mg l(-1)) and micro-aerobic (as DO < 0.7 mg l(-1)) conditions while no AOB-like bacterium was exactly matched among main bands. By the results, nitrite-oxidizing bacteria may be more tolerant to variations in oxygen, or the occupation of ammonia-oxidizing bacteria as dominant groups may have been inhibited by substrate starvation and high concentrations of nitrite-N in influent.

Tracheostomy can fatally exacerbate sleep-disordered breathing in multiple system atrophy

Tracheostomy has been employed to release the airway obstruction at the glottic level and to prevent sudden death in patients with multiple system atrophy (MSA). However, sudden death is possible even after tracheostomy. Nocturnal polysomnography showed that the apnea-hypopnea index became higher after tracheostomy, and all tracheostomized patients had frequent central sleep apneas.

Functional evaluations of the parotid and submandibular glands using dynamic magnetic resonance sialography

PURPOSE

To evaluate the functional differences between the parotid and submandibular glands using dynamic MR sialography.

METHODS

In 30 volunteers, the time-dependent changes (dynamic changes) in the maximum area of the detectable parotid and submandibular gland ducts on dynamic MR sialographic images were analysed.

RESULTS

Dynamic changes in the parotid gland ducts were detectable on MR sialographic images in all volunteers, but images of the submandibular gland ducts were detectable in only 23 volunteers. In addition, the dynamic changes in the submandibular gland ducts in these 23 subjects were less than those seen in the parotid gland ducts. A relationship was found between the changing ratio of parotid (Pearson r=0.448, P=0.013) or submandibular gland ducts (Pearson r=0.418, P=0.047) and the salivary flow rate during the stimulation period.

CONCLUSIONS

Dynamic MR sialography allows evaluation of rest and stimulated functioning and morphological evaluation of the parotid and submandibular glands. This technique appears to have many possible applications in the dental, medical and biological fields.

Identification and functional signature of genes regulated by structurally different ABL kinase inhibitors

Dasatinib is an ATP-competitive, multi-targeted SRC and ABL kinase inhibitor that can bind BCR-ABL in both the active and inactive conformations. From a clinical standpoint, dasatinib is particularly attractive because it has been shown to induce hematologic and cytogenetic responses in imatinib-resistant chronic myeloid leukemia patients. The fact because the combination of imatinib and dasatinib shows the additive/synergistic growth inhibition on wild-type p210 BCR-ABL-expressing cells, we reasoned that these ABL kinase inhibitors might induce the different molecular pathways. To address this question, we used DNA microarrays to identify genes whose transcription was altered by imatinib and dasatinib. K562 cells were cultured with imatinib or dasatinib for 16 h, and gene expression data were obtained from three independent microarray hybridizations. Almost all of the imatinib- and dasatinib-responsive genes appeared to be similarly increased or decreased in K562 cells; however, small subsets of genes were identified as selectively altered expression by either imatinib or dasatinib. The distinct genes that are selectively modulated by dasatinib are cyclin-dependent kinase 2 (CDK2) and CDK8, which had a maximal reduction of <5-fold in microarray screen. To assess the functional importance of dasatinib regulated genes, we used RNA interference to determine whether reduction of CDK2 and CDK8 affected the growth inhibition. K562 and TF-1BCR-ABL cells, pretreated with CDK2 or CDK8 small interfering RNA, showed additive growth inhibition with imatinib, but not with dasatinib. These findings demonstrate that the additive/synergistic growth inhibition by imatinib and dasatinib may be mediated in part by CDK2 and CDK8.

Dynamic magnetic resonance sialography as a new diagnostic technique for patients with Sjogren's syndrome

OBJECTIVE

To evaluate the clinical utility of dynamic magnetic resonance (MR) sialographic images as a diagnostic tool for patients with Sjögren's syndrome.

METHODS

The morphological findings and various kinds of functional parameters in volunteers on dynamic MR sialographic images were compared with those in five patients with definite Sjögren's syndrome.

RESULTS

On the MR sialographs of all five patients with Sjögren's syndrome, the so-called 'apple-tree appearance' was seen. The difference in two functional parameters using the dynamic MR sialographic data was elucidated between the two groups. The maximum area of the detectable ducts in the group of patients was significantly smaller (P < 0.001) than that in the group of volunteers. The ratio of change in the detectable ducts in the group of patients was significantly lower (P = 0.011) than that in the group of volunteers.

CONCLUSIONS

Our study suggests that dynamic MR sialographic data in addition to MR sialographic images might be useful for the diagnosis of Sjögren's syndrome.

Clinical significance and variation of the advanced calcified stylohyoid complex detected by panoramic radiographs among 80-year-old subjects

OBJECTIVES

To evaluate the clinical significance and variation of a calcified stylohyoid complex associated with advanced calcification as detected on panoramic radiographs among 80-year-old subjects.

METHODS

Panoramic radiographs of 659 patients (262 men and 397 women) and data of their general and dental health conditions were used for the evaluation of the relationship between a calcified stylohyoid complex and general health among 80-year-olds. This study was part of the 8020 Data Bank Survey, which was designed to collect the baseline data of general and dental health conditions in 80-year-old subjects. The morphology of the calcified stylohyoid complexes was allocated to one of 12 patterns. The lengths of the calcified stylohyoid complex were measured directly on the radiographs from the caudal margin of the tympanic plate to the tip of the styloid process.

RESULTS

All of the stylohyoid complexes from the 659 panoramic radiographs could be allocated to one of 12 morphological patterns, and some of their radiographic findings suggested calcification of the carotid artery and lymph nodes. In 80-year-old subjects, the average length of the calcified stylohyoid complexes was 36.7 mm, and ranged from 0.0 mm to 153.0 mm. There appeared to be correlations between the length of the calcified stylohyoid complex and serum calcium concentration and heel bone density, but not with the Community Periodontal Index (CPI).

CONCLUSIONS

Dentists should recognize the existence of morphological variation in calcified stylohyoid complexes, especially in length, apparent on panoramic radiographs of 80-year-old patients. In addition, the longer length of the calcified stylohyoid complexes in 80-year-old patients may be a predictor of bone density and high serum calcium concentration level. The findings from the present study may provide potentially life-saving information about elderly people.

Telomerase inhibition with a novel G-quadruplex-interactive agent, telomestatin: in vitro and in vivo studies in acute leukemia

The telomerase complex is responsible for telomere maintenance and represents a promising neoplasia therapeutic target. Recently, we have demonstrated that treatment with a G-quadruplex-interactive agent, telomestatin reproducibly inhibited telomerase activity in the BCR-ABL-positive leukemic cell lines. In the present study, we investigated the mechanisms of apoptosis induced by telomerase inhibition in acute leukemia. We have found the activation of caspase-3 and poly-(ADP-ribose) polymerase in telomestatin-treated U937 cells (PD20) and dominant-negative DN-hTERT-expressing U937 cells (PD25). Activation of p38 mitogen-activated protein (MAP) kinase and MKK3/6 was also found in telomestatin-treated U937 cells (PD20) and dominant-negative DN-hTERT-expressing U937 cells (PD25); however, activation of JNK and ASK1 was not detected in these cells. To examine the effect of p38 MAP kinase inhibition on growth properties and apoptosis in telomerase-inhibited cells, we cultured DN-hTERT-expressing U937 cells with or without SB203580. Dominant-negative-hTERT-expressing U937 cells stopped proliferation on PD25; however, a significant increase in growth rate was observed in the presence of SB203580. Treatment of SB203580 also reduced the induction of apoptosis in DN-hTERT-expressing U937 cells (PD25). These results suggest that p38 MAP kinase has a critical role for the induction of apoptosis in telomerase-inhibited leukemia cells. Further, we evaluated the effect of telomestatin on the growth of U937 cells in xenograft mouse model. Systemic intraperitoneal administration of telomestatin in U937 xenografts decreased tumor telomerase levels and reduced tumor volumes. Tumor tissue from telomestatin-treated animals exhibited marked apoptosis. None of the mice treated with telomestatin displayed any signs of toxicity. Taken together, these results lay the foundations for a program of drug development to achieve the dual aims of efficacy and selectivity in vivo.

Correlation between the incidence of central nodal necrosis in cervical lymph node metastasis and the extent of differentiation in oral squamous cell carcinoma

OBJECTIVES

To investigate the incidence of central nodal necrosis (CNN) in the cervical lymph nodes of patients with oral squamous cell carcinoma (SCC) and the factors that influence the formation of CNN.

METHODS

Lymph nodes shown as CNN on computed tomography (CT) films in 107 lymph nodes from 27 patients with oral SCC were selected. Lymph nodes with CNN on CT films were compared with the pathological findings of lymph nodes on specimens. We compared many kinds of factors influencing the formation of CNN, including the differentiated type, with the incidence of CNN.

RESULTS

Significant relationships were found between the incidence of CNN in metastatic lymph nodes and the presence of well-differentiated SCC and the presence of keratinization in tumour cells.

CONCLUSIONS

The results indicated that if a patient had SCC with low-grade differentiation, CNN in small lymph nodes would be difficult to detect on CT scan. Therefore, noting changes in lymph node density in the absence of CNN on CT scans is necessary in case the primary tumour is low-grade SCC.