Abstract P3-10-14: Breast cancer provider delay after the 2011 triple disaster in Fukushima, Japan

Introduction

Timely diagnosis and treatment is an indispensable part of breast cancer management. Delay of this process, also known as provider delay, can result in a deteriorated prognosis of affected patients. Although it has been suggested that disasters can impact cancer care and extend provider delay, there is little information available on long-term trends of breast cancer provider delay in post-disaster settings.

So-so district of Fukushima prefecture, Japan, experienced an earthquake, tsunami and the Fukushima Daiichi Nuclear Power Plant Accident in 2011. So-so district has areas falling within the mandatory, voluntary and non-evacuation ordered zones. Due to a long-term shortage of medical staff and closure of medical institutions post-disaster, patients with breast cancer may have experienced longer provider delay in this area.

Objectives

To compare provider delay of breast cancer patients and elucidate contributing factors to delay pre- and post-disaster, in an area severely affected by Japan's 2011 triple disaster.

Methods

We retrospectively investigated data of newly diagnosed breast cancer patients who undertook first medical consultation at the two main cancer centers in the non-evacuation ordered zone of So-so district from 2005 to 2016. Sociodemographic and clinical information was collected from medical records. The main outcome measure was median (days) from first medical consultation to start of breast cancer-specific treatment, pre- and post-disaster, using Mann-Whitney U test. Multivariate linear regression was then conducted to identify any factors which contributed to extended provider delay before and after the disaster.

Results

A total of 157 pre-disaster patients and 121 post-disaster patients were included in the study. There was no significant difference in the interval of median days of first medical consultation to start of first treatment pre- and post-disaster (40 vs. 39, p=0.82). Although diagnosis was made in a shorter interval post-disaster compared to pre-disaster (11 vs. 14, p=0.01) with significantly smaller median number of biopsies (1 vs. 1, p=0.001), this post-disaster improvement in diagnostic process was offset by deferred start of treatment after diagnosis (26 vs. 22, p=0.008). Among the pre-disaster patients, cancer detection by breast cancer screening program (p<0.001), being engaged in full-time job (p<0.042), and number of biopsies before diagnosis (p=0.005) contributed to longer provider delay in multivariate regression. However, consultation from other medical providers (p=0.03) was the only factor which significantly contributed to extended delay post-disaster, after controlling for multiple variables.

Conclusion

There was no significant increase in provider delay among breast cancer patients post-disaster. However, a median interval of 39 days from first medical consultation to start of treatment is much longer than other high-income countries, and shows much room for improvement in future.Introduction

Timely diagnosis and treatment is an indispensable part of breast cancer management. Delay of this process, also known as provider delay, can result in a deteriorated prognosis of affected patients. Although it has been suggested that disasters can impact cancer care and extend provider delay, there is little information available on long-term trends of breast cancer provider delay in post-disaster settings.

So-so district of Fukushima prefecture, Japan, experienced an earthquake, tsunami and the Fukushima Daiichi Nuclear Power Plant Accident in 2011. So-so district has areas falling within the mandatory, voluntary and non-evacuation ordered zones. Due to a long-term shortage of medical staff and closure of medical institutions post-disaster, patients with breast cancer may have experienced longer provider delay in this area.

Objectives

To compare provider delay of breast cancer patients and elucidate contributing factors to delay pre- and post-disaster, in an area severely affected by Japan's 2011 triple disaster.

Methods

We retrospectively investigated data of newly diagnosed breast cancer patients who undertook first medical consultation at the two main cancer centers in the non-evacuation ordered zone of So-so district from 2005 to 2016. Sociodemographic and clinical information was collected from medical records. The main outcome measure was median (days) from first medical consultation to start of breast cancer-specific treatment, pre- and post-disaster, using Mann-Whitney U test. Multivariate linear regression was then conducted to identify any factors which contributed to extended provider delay before and after the disaster.

Results

A total of 157 pre-disaster patients and 121 post-disaster patients were included in the study. There was no significant difference in the interval of median days of first medical consultation to start of first treatment pre- and post-disaster (40 vs. 39, p=0.82). Although diagnosis was made in a shorter interval post-disaster compared to pre-disaster (11 vs. 14, p=0.01) with significantly smaller median number of biopsies (1 vs. 1, p=0.001), this post-disaster improvement in diagnostic process was offset by deferred start of treatment after diagnosis (26 vs. 22, p=0.008). Among the pre-disaster patients, cancer detection by breast cancer screening program (p<0.001), being engaged in full-time job (p<0.042), and number of biopsies before diagnosis (p=0.005) contributed to longer provider delay in multivariate regression. However, consultation from other medical providers (p=0.03) was the only factor which significantly contributed to extended delay post-disaster, after controlling for multiple variables.

Conclusion

There was no significant increase in provider delay among breast cancer patients post-disaster. However, a median interval of 39 days from first medical consultation to start of treatment is much longer than other high-income countries, and shows much room for improvement in future.

Citation Format: Ozaki A, Leppold C, Tsubokura M, Sawano T, Tsukada M, Ohira H. Breast cancer provider delay after the 2011 triple disaster in Fukushima, Japan [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-10-14.

Abstract P6-12-04: Delayed hospital visits in patients with breast cancer after the great East Japan earthquake and the subsequent Fukushima Daiichi nuclear power plant accident: A retrospective comparative analysis

Introduction

In breast cancer, delay in first presentation and self-interruption of continuous treatment are associated with lower survival. It has been suggested that risk factors for such behavioral patterns include poor social support.

Minamisoma City, located within a 30 kilometers radius from Fukushima Daiichi nuclear power plant, has experienced rapid change in social structures following the Great East Japan Earthquake and the subsequent power plant accident. There has been a mass evacuation among young and middle-aged generations for fear of potential irradiation, and this has resulted in the separation of families and friends. These changes may have resulted in a deterioration of social support for residents, which could consequently lead to changed patterns of behavior in diseases such as breast cancer.

Objectives

This study compared the behavioral patterns before and after the disasters in patients with breast cancer in Minamisoma City.

Methods

We retrospectively analyzed data from patients with breast cancer who were diagnosed from January 2008 through March 2015 in the two main cancer centers in Minamisoma City. Demographic and clinical information was extracted from medical records, including age, stage, pathological findings, treatment, and the reason for the first hospital visit. The main outcome was a change of interval from the appearance of initial symptoms to the first hospital visit before and after the disasters. We also assessed whether continuous follow-up was maintained after the disasters. We used an unpaired t-test for numerical variables and a chi-squared test for categorical variables.

Results

A total of 102 and 97 patients were diagnosed with breast cancer before and after the disasters, respectively. There were no statistically significant differences between the 2 groups concerning average age (61 years old vs. 61 years old, p=1), stage 3 or 4 cancer (18% vs. 17%, p=0.81), invasive cancer (92% vs. 93%, p=0.87) and symptomatic patients (75% vs. 74%, p=0.74), respectively. However, after the disasters, there were significant increases in the ratio of patients with more than a one-year delay from the appearance of the initial symptom to the first hospital visit (5.4% vs. 15%, p<0.05). The patients with more than a one-year delay had a significantly higher ratio of advanced stage cancer compared with patients who visited a hospital earlier. Continuous follow-up was maintained in all patients diagnosed after the disasters.

Discussion

The characteristics of patients were not significantly different before and after the disasters, while the ratio of patients with more than a one-year delay of the first hospital visit significantly increased after the disasters. Although information on social capital and other sociodemographic factors was not available, we speculate that poor social support due to changed social structures after the disasters might contribute to delay in first presentation in symptomatic breast cancer patients. Further study is warranted to clarify the factors associated with delayed hospital visits, in order to establish effective health interventions in the aftermath of mass disasters.

Citation Format: Ozaki A, Tsubokura M, Nomura S, Morita T, Ochi S, Kato S, Saji S, Yokota T, Leppold C, Tanimoto T, Kami M, Tsukada M, Ohira H. Delayed hospital visits in patients with breast cancer after the great East Japan earthquake and the subsequent Fukushima Daiichi nuclear power plant accident: A retrospective comparative analysis. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-12-04.

Frequency-dependent signal processing in apical dendrites of hippocampal CA1 pyramidal cells

Depending on an animal's behavioral state, hippocampal CA1 pyramidal cells receive distinct patterns of excitatory and inhibitory synaptic inputs. The time-dependent changes in the frequencies of these inputs and the nonuniform distribution of voltage-gated channels lead to dynamic fluctuations in membrane conductance. In this study, using a whole-cell patch-clamp method, we attempted to record and analyze the frequency dependencies of membrane responsiveness in Wistar rat hippocampal CA1 pyramidal cells following noise current injection directly into dendrites and somata under pharmacological blockade of all synaptic inputs. To estimate the frequency-dependent properties of membrane potential, membrane impedance was determined from the voltage response divided by the input current in the frequency domain. The cell membrane of most neurons showed low-pass filtering properties in all regions. In particular, the properties were strongly expressed in the somata or proximal dendrites. Moreover, the data revealed nonuniform distribution of dendritic impedance, which was high in the intermediate segment of the apical dendritic shaft (∼220-260μm from the soma). The low-pass filtering properties in the apical dendrites were more enhanced by membrane depolarization than those in the somata. Coherence spectral analysis revealed high coherence between the input signal and the output voltage response in the theta-gamma frequency range, and large lags emerged in the distal dendrites in the gamma frequency range. Our results suggest that apical dendrites of hippocampal CA1 pyramidal cells integrate synaptic inputs according to the frequency components of the input signal along the dendritic segments receiving the inputs.

Chemical and physical properties of sulfated silk fabrics

Silk fabrics were treated with chlorosulphonic acid in pyridine for different times. The amount of sulfur bound to silk increased during the first 2 h of reaction and then reached a plateau. The amino acidic pattern of sulfated silk remained essentially unchanged for short reaction times (< or =2 h). Longer reaction times resulted in drastic changes in the concentration of Asp, Glu, and Tyr. Surface morphology and texture of silk fabrics changed upon sulfation. Warp and weft yarns became progressively thinner, and deposits of foreign material appeared on the fiber surface. Changes were more evident at longer reaction times (> or =2 h). Spectroscopic analyses performed by FT-IR and FT-Raman showed the appearance of new bands attributable to various vibrations of sulfated groups. The IR bands at 1049 and 1014 cm-1, due to organic sulfate salts, were particularly intense. Bands assigned to alkyl sulfates and sulfonamides appeared in the 1300-1180 cm-1 range. Organic covalent sulfates displayed a weak but distinct IR band at 1385 cm-1. Both IR and Raman spectra revealed that silk fibroin mainly bound sulfates through the hydroxyl groups of Ser and Tyr, while involvement of amines could not be proved. Changes observed in the amide I and II range indicated an increase of the degree of molecular disorder of sulfated silk. Accordingly, the I850/I830 intensity ratio between the two Tyr bands at 850-830 cm-1 increased from 1.41 to 1.52, indicating a more exposed state of Tyr residues in sulfated silk. TGA, DSC, and TG analyses showed that sulfated silk attained a higher thermal stability. A thermal transition attributable to sulfated silk fibroin fractions appeared at about 260 degrees C in the DSC thermograms.

The relation between spike-timing dependent plasticity and Ca2+ dynamics in the hippocampal CA1 network

In our previous study, spike timing dependent synaptic plasticity (STDP) was investigated in the CA1 area of rat hippocampal slices using optical imaging. It was revealed that the profiles of STDP could be classified into two types depending upon layer specific location along the dendrite. The first was characterized by a symmetric time window observed in the proximal region of the stratum radiatum (SR), and the second by an asymmetric time window in the distal region of the SR. Our methods involved the bath-application of bicuculline (GABA(A) receptor antagonist) to hippocampal slices, which revealed that GABAergic interneuron projections were responsible for the symmetry of a time window. In this study, the intracellular Ca2+ increase of hippocampal CA1 neurons, induced by the protocol of timing between pre- and post-synaptic excitation (i.e. STDP protocol), was measured spatially by using optical imaging to investigate how the triggering of STDP is dependent on intracellular calcium concentration. We found that the magnitude of STDP was closely related to the rate of Ca2+ increase ("velocity") of calcium transient during application of induction stimuli. Location dependency was also analyzed in terms of Ca2+ influx. Furthermore, it was shown that decay time constant of Ca2+ dynamics during the application of STDP-inducing stimuli was also significantly correlated with STDP.

Fine mapping of the clubroot resistance gene, Crr3, in Brassica rapa

A linkage map of Chinese cabbage (Brassica rapa) was constructed to localize the clubroot resistance (CR) gene, Crr3. Quantitative trait loci analysis using an F(3) population revealed a sharp peak in the logarithm of odds score around the sequence-tagged site (STS) marker, OPC11-2S. Therefore, this region contained Crr3. Nucleotide sequences of OPC11-2S and its proximal markers showed homology to sequences in the top arm of Arabidopsis chromosome 3, suggesting a synteny between the two species. For fine mapping of Crr3, a number of STS markers were developed based on genomic information from Arabidopsis. We obtained polymorphisms in 23 Arabidopsis-derived STS markers, 11 of which were closely linked to Crr3. The precise position of Crr3 was determined using a population of 888 F(2) plants. Eighty plants showing recombination around Crr3 locus were selected and used for the mapping. A fine map of 4.74 cM was obtained, in which two markers (BrSTS-41 and BrSTS-44) and three markers (OPC11-2S, BrSTS-54 and BrSTS-61) were cosegregated. Marker genotypes of the 21 selected F(2) families and CR tests of their progenies strongly suggested that the Crr3 gene is located in a 0.35 cM segment between the two markers, BrSTS-33 and BrSTS-78.

Fine mapping of the clubroot resistance gene, Crr3, in Brassica rapa

A linkage map of Chinese cabbage (Brassica rapa) was constructed to localize the clubroot resistance (CR) gene, Crr3. Quantitative trait loci analysis using an F(3) population revealed a sharp peak in the logarithm of odds score around the sequence-tagged site (STS) marker, OPC11-2S. Therefore, this region contained Crr3. Nucleotide sequences of OPC11-2S and its proximal markers showed homology to sequences in the top arm of Arabidopsis chromosome 3, suggesting a synteny between the two species. For fine mapping of Crr3, a number of STS markers were developed based on genomic information from Arabidopsis. We obtained polymorphisms in 23 Arabidopsis-derived STS markers, 11 of which were closely linked to Crr3. The precise position of Crr3 was determined using a population of 888 F(2) plants. Eighty plants showing recombination around Crr3 locus were selected and used for the mapping. A fine map of 4.74 cM was obtained, in which two markers (BrSTS-41 and BrSTS-44) and three markers (OPC11-2S, BrSTS-54 and BrSTS-61) were cosegregated. Marker genotypes of the 21 selected F(2) families and CR tests of their progenies strongly suggested that the Crr3 gene is located in a 0.35 cM segment between the two markers, BrSTS-33 and BrSTS-78.

Phase shift of subthreshold theta oscillation in hippocampal CA1 pyramidal cell membrane by excitatory synaptic inputs

Hippocampal CA1 neurons receive multiple rhythmical inputs with relatively independent phases during theta activity. It, however, remains to be determined how these multiple rhythmical inputs affect oscillation properties in membrane potential of the CA1 pyramidal cell. In order to investigate oscillation properties in the subthreshold membrane potential, we generated oscillations in the membrane potential of the CA1 pyramidal cells in rat hippocampal slices in vitro with a sinusoidal current injection into the pyramidal soma at theta band frequencies (4-7 Hz), and analyzed effect of rhythmically excitatory synaptic inputs. The Schaffer collaterals were stimulated with a cyclic Gaussian stimulation method, whose pulse intervals were distributed at 10 pulses/cycle (5 cycles/s). We found that the cyclic Gaussian stimulations induced membrane potential oscillations and their phase delays from the mean of the pulse distribution were dependent on membrane potential oscillation amplitude. We applied four pairs of cyclic Gaussian stimulations and somatic sinusoidal current stimulations at the same frequency (5 Hz) with varying phase differences (-pi/2, 0, pi/2, pi rad). The paired stimulations induced phase distributions of the oscillation in the membrane potential, which showed a dependency on an increasing membrane potential oscillation amplitude response to cyclic Gaussian stimulation. This membrane potential dynamic was exhibited by the mixture of the membrane potential oscillation-amplitude-dependent phase delay and the linear summation of the two sinusoidal waves. These suggest that phases of the membrane potential oscillation are modulated by excitatory synaptic inputs. This phase-modulation by excitatory synaptic inputs may play a crucial role for memory operation in the hippocampus.

STS observations of Landau levels at graphite surfaces

Scanning tunneling spectroscopy (STS) measurements were made on surfaces of two different kinds of graphite samples, Kish graphite and highly oriented pyrolytic graphite (HOPG), at very low temperatures and in high magnetic fields. We observed a series of peaks in the tunnel spectra associated with Landau quantization of the quasi-two-dimensional electrons and holes. A comparison with the calculated local density of states at the surface layers allows us to identify Kish graphite as bulk graphite and HOPG as graphite with a finite thickness of 40 layers. This explains the qualitative difference between the two graphites reported in the recent transport measurements which suggested the quantum-Hall effect in HOPG. This work demonstrates how powerful the combined approach between the high quality STS measurement and the first-principles calculation is in material science.

The spatiotemporal learning rule and its efficiency in separating spatiotemporal patterns

The hippocampus plays an important role in the course of establishing long-term memory, i.e., to make short-term memory of spatially and temporally associated input information. In 1996 (Tsukada et al. 1996), the spatiotemporal learning rule was proposed based on differences observed in hippocampal long-term potentiation (LTP) induced by various spatiotemporal pattern stimuli. One essential point of this learning rule is that the change of synaptic weight depends on both spatial coincidence and the temporal summation of input pulses. We applied this rule to a single-layered neural network and compared its ability to separate spatiotemporal patterns with that of other rules, including the Hebbian learning rule and its extended rules. The simulated results showed that the spatiotemporal learning rule had the highest efficiency in discriminating spatiotemporal pattern sequences, while the Hebbian learning rule (including its extended rules) was sensitive to differences in spatial patterns.

Induction of hepatic metallothionein synthesis by endoplasmic reticulum stress in mice

Metallothionein (MT) is a small sulfhydryl-rich protein whose levels are elevated by various inducers of organelle stresses, such as nuclear stress (cisplatin), mitochondrial stress (antimycin A, 2,4-dinitrophenol) and lysosomal stress (paraquat). Although abnormal folding of protein in the endoplasmic reticulum (ER) causes ER stress, induction of MT synthesis by ER stress has never been investigated. In this study, we examined the induction of MT by an inducer of ER stress, tunicamycin (Tun), which induces ER stress by inhibiting N-linked glycosylation of protein in the ER. Administration of Tun (0.5-1.5 mg/kg, sc) increased hepatic MT levels in C57BL/6J mice (3.1-fold). The maximal increase in hepatic MT was observed 48-96 h after the administration of Tun (1.0 mg/kg). Expressions of MT-I, II and glucose-regulated protein 78 (Bip/GRP78), which is a molecular chaperone induced by ER stress, mRNA were also detected by administration of Tun. Thapsigargin (Thap), a generator of ER stress by inhibiting ER Ca(2+)-ATPase, also increased both hepatic MT levels and expression of MT-I and -II mRNA. The level of expression of Bip/GRP78 mRNA induced by Tun administration in MT-null mice was greater than that in wild-type mice. Taken together, these findings suggest that inhibitors of ER are potent inducers of MT.

A novel locus for clubroot resistance in Brassica rapa and its linkage markers

An inbred turnip ( Brassica rapa syn. campestris) line, N-WMR-3, which carries the trait of clubroot resistance (CR) from a European turnip, Milan White, was crossed with a clubroot-susceptible doubled haploid line, A9709. A segregating F(3) population was obtained by single-seed descent of F(2) plants and used for a genetic analysis. Segregation of CR in the F(3) population suggested that CR is controlled by a major gene. Two RAPD markers, OPC11-1 and OPC11-2, were obtained as candidates of linkage markers by bulked segregant analysis. These were converted to sequence-tagged site markers, by cloning and sequencing of the polymorphic bands, and named OPC11-1S and OPC11-2S, respectively. The specific primer pairs for OPC11-1S amplified a clear dominant band, while the primer pairs for OPC11-2S resulted in co-dominant bands. Frequency distributions and statistical analyses indicate the presence of a major dominant CR gene linked to these two markers. The present marker for CR was independent of the previously found CR loci, Crr1 and Crr2. Genotypic distribution and statistical analyses did not show any evidence of CR alleles on Crr1 and Crr2 loci in N-WMR-3. The present study clearly demonstrates that B. rapa has at least three CR loci. Therefore, the new CR locus was named Crr3. The present locus may be useful in breeding CR Chinese cabbage cultivars to overcome the decay of present CR cultivars.

Tubular osteopontin expression in patients with ANCA-associated glomerulonephritis

OBJECTIVE

To elucidate the role of osteopontin (OPN) in monocyte recruitment in crescentic glomerulonephritis, we investigated immunohistochemical localization of OPN in the kidney and its correlation with clinical and histopathologic parameters in biopsy specimens of patients with myeloperoxidase antineutrophil cytoplasmic autoantibody- (MPO-ANCA) associated glomerulonephritis.

METHODS

Twelve patients with MPO-ANCA-associated glomerulonephritis were enrolled in this study. Clinical parameters such as creatinine clearance and urinary protein excretion of each patient were obtained at the time of biopsy. Paraffin-embedded sections were used for immunohistochemical staining using the LSAB method. Five cortical interstitial fields randomly selected at original magnification x 200 were assessed using a computer-assisted color image analyzer. Tubular OPN expression was assessed as the percentage of positive area in the tubulointerstitium. Double immunofluorescent staining using antibodies against OPN and alpha(v)beta3 was performed.

RESULTS

In all of the cases studied, OPN was occasionally localized within the glomeruli, and expressed slightly in proximal tubular epithelium and significantly in distal tubular epithelium. Tubular OPN expression tended to be promoted in the interstitium infiltrating by numerous monocytes/macrophages. The extent of tubular OPN expression was positively correlated with serum ANCA titers and urinary OPN concentrations. Enhanced alpha(v)beta3 expression appeared in the distal tubular epithelium expressing OPN.

CONCLUSION

These results suggest that inducible expression of OPN and alpha(v)beta3 in the tubular epithelium seems to be associated with interstitial moncyte infiltration and subsequent tubulointerstitial changes in human MPO-ANCA-associated glomerulonephritis.

Quantum loop current in a C(60) molecular bridge

The existence of a quantum loop current in a C(60) molecular bridge is predicted using the Green's function method. The model for the molecular bridge consists of a C(60) molecule attached to one-dimensional conductive electrodes. It is shown that the loop current is related to the degeneracy of the energy levels of the C(60) molecule. Specific to this loop current is its magnitude which is much larger than that of the source-drain current. The associated magnetic moment also shows certain remarkable features such as its inversion with the energy across the molecular levels and the restriction of its direction onto a single plane.

Vascular responses to beta-adrenoceptor subtype-selective agonists with and without endothelium in rat common carotid arteries

1. Using the cannula inserting method, vasodilator responses to beta-adrenoceptor agonists (isoprenaline, denopamine and procaterol) were investigated in isolated and perfused rat common carotid arteries. 2. Each beta-adrenoceptor agonist induced a vasodilation in preparations preconstricted by phenylephrine in a dose-related manner. The potencies were in the order of isoprenaline > procaterol >> denopamine. 3. Denopamine-induced dilations were significantly inhibited by 1 nmol betaxolol (a selective beta1-adrenoceptor antagonist), but it was not influenced by 1 nmol ICI 118,551 (a selective beta2-adrenoceptor antagonist). On the other hand, procaterol-induced vasodilations were significantly inhibited by 1 nmol ICI 118,551 but not modified by 10 nmol betaxolol. 4. ACh-induced vasodilations disappeared after intraluminal saponin injection to remove endothelium, but procaterol- and denopamine-induced dilations were not modified by removal of the endothelium. 5. Pretreatment with L-NG-nitroarginine methyl ester (L-NAME) readily inhibited ACh-induced vasodilations. However, neither procaterol- or denopamine-induced vasodilation was modified by L-NAME treatment. 6. From these results, it is concluded that in the rat common carotid arteries (1) there are abundant beta2- and a few beta1-adrenoceptors, and (2) there is no participation of the endothelium-dependent mechanism in beta-adrenoceptor mediated vasodilations.

Damping mechanism in dynamic force microscopy

A general theory is presented which describes the damping in dynamic force microscopy due to the proximity of the surface, consistently with resonant frequency shift effects. Orders of magnitude for the experimentally measured "dissipation" and image corrugation are reproduced. It is suggested that the damping does not mainly result from energy dissipation, but arises because not all solutions of the microlever equation of motion are accessible. The damping is related to the multivalued nature of the analytical resonance curve, which appears at some critical tip-surface separation.

Effect of temperature on responses of dog isolated lingual and mesenteric arteries to vasoactive substances

1. The effects of temperature on submaximal vasoconstriction to an intraluminal administration of noradrenaline (NA), phenylephrine, tyramine and KCl were investigated in canine isolated and perfused lingual and mesenteric arteries, using the cannula-inserting method. 2. In lingual arteries, cooling (from 37 to 27 degrees C) caused significant depression of vasoconstriction to the four vasoactive substances used. Rewarming (to 37 degrees C) induced a significant augmentation of constriction by NA, phenylephrine and KCl, but not tyramine. 3. In mesenteric arteries, cooling depressed tyramine- and KCl-induced constrictions, but had no effect on NA- and phenylephrine-induced vasoconstriction. Only in the case of KCl-induced constrictions did rewarming induce a potentiation of the vasoconstrictor response. 4. We conclude that: (i) cooling induces a depression of voltage-dependent Ca2+ channels and rewarming may induce a potentiation of Ca2+ channels in both arteries; (ii) alpha1-adrenoceptor-operated Ca2+ channels are depressed by cooling in lingual arteries but not in mesenteric arteries; and (iii) cooling may induce an attenuation of the re-uptake function in sympathetic nerve terminals in both arteries and this attenuation may be not rapidly restored by acute rewarming.

Transganglionic gracile response following limb amputation in man

Gracile neuroaxonal dystrophy (NAD) is an distinctive morphological alteration of central projecting axon terminals of dorsal root ganglion neurons. Experimentally, lower limb amputation has been shown to accelerate the formation of gracile NAD, suggesting that the transganglionic response to peripheral axotomy may play a role in its development. To determine if a similar response occurs in the human sensory nervous system following peripheral nerve injury, we have performed postmortem histopathological examinations of the dorsal column nuclei of three patients (aged 15, 55, and 77 years old); all of whom had undergone accidental or therapeutic unilateral limb amputation (1 year, 38 years, and 1 year 8 months prior to death, respectively). In a 15-year-old man who underwent therapeutic leg amputation, the gracile nuclei on the transected side revealed reactive gliosis and many small axonal spheroids. The spheroids and fine neurites were immunolabelled with antibodies for growth-associated protein-43, ubiquitin and neuropeptide Y (NPY). Neither routine histological nor immunohistochemical methods demonstrated comparable changes in the contralateral gracile nucleus. In a 77-year-old man who underwent leg amputation, the gracile nucleus on the amputated side was gliotic and showed several NPY and ubiquitin-immunoreactive spheroids, which were not seen in the contralateral non-transected side. A 55-year-old man with a history of accidental arm amputation showed well-developed NAD in the cuneate nucleus only on the transected side. This study clearly demonstrates the occurrence of transganglionic response to limb amputation in human dorsal column nuclei. The extent of the regenerative and/or degenerative responses may vary depending on the age of the patient and the time interval following the peripheral axotomy.

Chaotic stimulus dependent long-term potentiation in the hippocampal CA1 area

In our previous report [Tsukada, M., Aihara, T., Saito, H., Kato, H., 1996. Neural Netw. 9, 1357-1365], the temporal pattern sensitivity of long-term potentiation (LTP) in hippocampal CA1 neurons was estimated by using Markov chain stimuli (MS) with different values of the serial correlation coefficient rho1 between successive interstimulus-intervals. In this paper, the effect of chaotic stimuli (CS) on induction of LTP in the hippocampal CA1 area was investigated in comparison with that of MS and periodic pattern stimuli (PS). The CS were produced by a modified Bernoulli map, so that interstimulus sequences with various values of rho1 can be generated by changing the parameter B. These stimuli had an identical first order statistics (mean interstimulus-interval), but their higher order statistics such as the serial correlation coefficients were different. The LTP induced by CS at B = 2 was significantly larger in magnitude than that of PS and MS, and also depended on the initial value of CS at B = 2 and 3. These results suggest that chaotic signals play an important role for memory coding in the hippocampal CA1 network.

Fast and stable method for simulating quantum electron dynamics

A fast and stable method is formulated to compute the time evolution of a wave function by numerically solving the time-dependent Schrodinger equation. This method is a real-space-real-time evolution method implemented by several computational techniques such as Suzuki's exponential product, Cayley's form, the finite differential method, and an operator named adhesive operator. This method conserves the norm of the wave function, manages periodic conditions and adaptive mesh refinement technique, and is suitable for vector- and parallel-type supercomputers. Applying this method to some simple electron dynamics, we confirmed the efficiency and accuracy of the method for simulating fast time-dependent quantum phenomena.

New silk protein: modification of silk protein by gene engineering for production of biomaterials

The interest in silk fibroin morphology and structure have increased due to its attractiveness for bio-related applications. Silk fibers have been used as sutures for a long time in the surgical field, due to the biocompatibility of silk fibroin fibers with human living tissue. In addition, it has been demonstrated that silk can be used as a substrate for enzyme immobilization in biosensors. A more complete understanding of silk structure would provide the possibility to further exploit silk fibroin for a wide range of new uses, such as the production of oxygen-permeable membranes and biocompatible materials. Silk fibroin-based membranes could be utilized as soft tissue compatible polymers. Baculovirus-mediated transgenesis of the silkworm allows specific alterations in a target sequence. Homologous recombination of a foreign gene downstream from a powerful promoter, such as the fibroin promoter, would allow the constitutive production of a useful protein in the silkworm and the modification of the character of silk protein. A chimeric protein consisted of fibroin and green fluorescent protein was expressed under the control of fibroin in the posterior silk gland and the gene product was spun into the cocoon layer. This technique, gene targeting, will lead to the modification and enhancement of physicochemical properties of silk protein.

[Case-control study of risk factors for cedar pollinosis among parents of 3-year-old children]

PURPOSE

To identify risk factors associated with cedar pollinosis among parents of three-year-old children.

METHODS

The subjects were parents whose children underwent health examination at the age of three years in September and October 1997 in Tochigi prefecture. We distributed questionnaires to the examinees beforehand with the request that they be filled in and brought to the examination site. Information on parents' environmental factors (place of residence, type and structure of housing, and distance from roads with heavy traffic), and mothers' past history and family history of allergic diseases was obtained. We defined cedar pollinosis in terms of three symptoms, sneezing, nasal discharge, and nasal obstruction, between February and May. Controls were those who did not have any of the three symptoms. Environmental factors were assessed with univariate and multivariate analyses using unconditional logistic models. Maternal genetic factors were also analyzed with odds ratios and 95% confidence intervals calculated for each. We also compared odds ratios of environmental factors between groups with and without genetic factors.

RESULTS

Of the parents of children taking the health examination, 90.2% took part (2,968 of 3,291 couples). Information was obtained from 2,846 mothers and 2,905 fathers. Mother and father cases were 312 and 229, and controls were 1,857 and 1,934, respectively. For the univariate analysis of environmental factors, place of residence (residential area/agricultural area), type of housing (apartment complex/solitary house), structure (reinforced concrete building/wooden house), and distance from heavy traffic (< 100 m/100 m+) were positively related to cedar pollinosis. For the multivariate analysis using unconditional logistic models, the odds ratio was significantly high for distance from heavy traffic (< 100 m/100 m+) among fathers. Mothers' past history and family history of allergic diseases showed high odds ratios for cedar pollinosis. We classified groups with and without past and family histories of allergic diseases (group with and without genetic factors) for assessment with multivariate analyses. Odds ratios for the group with an allergic history were higher than for those without such a history, but difference for factors such as, distance from heavy traffic type of housing, and structure were not statistically significant.

CONCLUSION

Risk of cedar pollinosis increases with distance from heavy traffic among fathers. Mothers with histories of allergy show slightly elevated odds ratios for environmental factors, but without statistic significance.

13-cis retinoic acid exerts its specific activity on human sebocytes through selective intracellular isomerization to all-trans retinoic acid and binding to retinoid acid receptors

Despite its potent biologic effect on human sebocytes, 13-cis retinoic acid exhibits low binding affinity for cellular retinoic acid binding proteins and nuclear retinoid receptors. Hence, 13-cis retinoic acid may represent a pro-drug possibly acting through all-trans isomerization. In this study, marked isomerization of 13-cis retinoic acid has been confirmed in cultured SZ95 sebocytes showing 2- to 15-fold higher levels of all-trans retinoic acid at 12-72 h, as measured by high performance liquid chromatography. In contrast, only low amounts of all-trans retinoic acid were converted intracellularly to its 13-cis isoform. 9-cis retinoic acid was not detected after either 13-cis retinoic acid or all-trans retinoic acid treatment. The rapid isomerization of 13-cis retinoic acid to high levels of all-trans retinoic acid was a sebocyte-specific event, as no significant isomerization of 13-cis retinoic acid to all-trans retinoic acid occurred in HaCaT keratinocytes. De novo mRNA expression of cytochrome P450 1A1, a major xenobiotic metabolizing enzyme, in SZ95 sebocytes was induced by all-trans retinoic acid, but not by 13-cis retinoic acid. In addition, mRNA levels of cellular retinoic acid-binding protein II, which is supposed to regulate the concentration of intracellular all-trans retinoic acid, rapidly increased under all-trans retinoic acid treatment (30 min-6 h), whereas the 13-cis retinoic acid effect was markedly weaker and delayed. Both 13-cis retinoic acid and all-trans retinoic acid suppressed mRNA expression of cytochrome P450 1A2. In parallel experiments, 13-cis retinoic acid significantly reduced SZ95 sebocyte proliferation at 10-7 M, show- ing 30-40% inhibition after 9 d. All-trans retinoic acid and 9-cis retinoic acid exhibited similar anti-proliferative effects. AGN 193109, a pan-antagonist of the retinoic acid receptors, antagonized the anti-proliferative activity of all retinoic acid isomers tested in a concentration-dependent manner with complete abolishment at ratios of 1:10 13-cis retinoic acid and 1:1 all-trans retinoic acid. Coincubation of SZ95 sebocytes with 13-cis retinoic acid and AGN 193109 did not alter the intracellular concentration of 13-cis retinoic acid and its isomerization profile. In contrast, the retinoid X receptor antagonist CD 3507 did not affect the inhibition of SZ95 sebocyte proliferation induced by retinoic acids. Our findings indicate: (i) a selective 13-cis retinoic acid isomerization to all-trans retinoic acid in the intracellular compartment of SZ95 sebocytes; (ii) a reduced all-trans retinoic acid inactivation process after 13-cis retinoic acid treatment as compared with treatment with all-trans retinoic acid; and (iii) a retinoic acid receptor-mediated inhibition of SZ95 sebocyte proliferation. These data explain the sebocyte-specific activity of 13-cis retinoic acid and support a pro-drug/drug relation between 13-cis retinoic acid and all-trans retinoic acid.

Enhancement of vasoconstrictor responses to 5-HT but no to methoxamine by cooling in isolated dog lingual and mesenteric arteries

The effect of temperature on submaximal vasoconstrictions to an intraluminal injection of serotonin (5-HT) and methoxamine was investigated in isolated and perfused canine lingual and mesenteric arteries, using the cannula insertion method. In both arteries cooling (from 37 degrees C to 27 degrees C) caused a remarkable enhancement of vasoconstriction to 5-HT, but did not to methoxamine. In lingual arteries, methoxamine-induced constrictions were strongly depressed, although those were slightly depressed in mesenteric arteries. It is assumed that 5-HT produces an important role to modulate vascular tonicity in low temperature conditions.

Heparin cofactor II inhibits thrombus formation in a rat thrombosis model

Heparin cofactor II is postulated to be an extravascular thrombin inhibitor that is physiologically stimulated by dermatan sulfate. However, the role of heparin cofactor II has not yet been clearly demonstrated in vivo. In this study, we estimated the antithrombotic effect of heparin cofactor II administered exogenously in a rat model of thrombosis. Thrombus was induced in the rat femoral artery by endothelial damage due to the photochemical reaction between systemically injected rose bengal and transillumination with green light. Pretreatment with heparin cofactor II significantly prolonged the time required to occlude the femoral artery (occlusion time) in a dose-dependent manner. At an effective dose in this thrombosis model, heparin cofactor II did not prolong the activated partial thromboplastin time and the prothrombin time in normal rats. Argatroban, a selective synthetic thrombin inhibitor, significantly prolonged the occlusion time. However, argatroban also prolonged the activated partial thromboplastin time and prothrombin time at an effective dose. These results suggest that the administration of heparin cofactor II in vivo effectively inhibited thrombus formation on the vessel walls whose endothelium is damaged without a prolongation of the coagulation time while heparin cofactor II may also inhibit the thrombin activity in the subendothelial tissue in vivo.

Two dynamic processes for the induction of long-term potentiation in hippocampal CA1 neurons

This work sets out to investigate fast and slow dynamic processes and how they effect the induction of long-term potentiation (LTP). Functionally, the fast process will work as a time window to take a spatial coincidence among various inputs projected to the hippocampus, and the slow process will work as a temporal integrator of a sequence of dynamic events. Firstly, the two factors were studied using a "burst" stimulus and a "long-interval patterns" stimulus. Secondly, we propose that, for the induction of LTP, there are two dynamic processes, fast and slow, which are productively activated by bursts and long-interval patterns. The model parameters, a time constant of short dynamics and one of long dynamics, were determined by fitting the values obtained from model simulation to the experimental data. A molecular factor or cellular factors with these two time constants are likely to be induced in LTP induction.

Bradykinin-induced vascular responses in dog isolated lingual artery

1. Kinin-induced vascular responses were studied and kinin receptor subtypes were characterized in canine isolated and preconstricted lingual arteries. 2. A low dose of bradykinin (BK; < 3 x 10(-14) mol) induced only vasodilation, while a higher dose of BK (> 3 x 10(-13) mol) frequently induced a biphasic response: a transient constriction followed by dilation. 3. The BK-induced vasodilation was mostly endothelium dependent but was also partly endothelium independent because although the dilation response was greatly reduced after removal of the endothelium, it was not completely abolished. 4. The dilation response to BK was significantly inhibited by the B2 kinin receptor antagonist HOE 140 and was partly reduced by indomethacin (10 mumol/L) (P < 0.05). 5. Bradykinin-induced vasoconstriction was enhanced in endothelium-denuded preparations. The constriction was significantly inhibited by HOE 140 (10(-10) mol/L). The BK-induced responses were not affected by the B1 kinin receptor antagonist des-Arg9-[Leu8]-BK (3 x 10(-11) mol/L). 6. The B1 kinin receptor agonist des-Arg9-BK (> 10(-12) mol/L) produced vasodilation in 60% of endothelium-intact preparations. In 20% of the endothelium-intact preparations des-Arg9-BK produced a biphasic response: weak vasoconstriction followed by weak vasodilation. The des-Arg9-BK-induced dilation and constriction were significantly inhibited by des-Arg9-[Leu8]-BK (3 x 10(-11) mol/L), but were not affected by HOE 140 (10(-10) mol/L). 7. In conclusion, it appears that both B1 and B2 kinin receptors are present in the dog lingual artery. Both receptor subtypes mediate either vasodilation or vasoconstriction and BK-induced vasodilation is mostly endothelium dependent, although it may also be partially prostaglandin dependent.

[Relationship between breast milk and atopic dermatitis in children]

OBJECTIVE

To determine whether or not dioxins and furans in breast milk have a role in the prevalence of atopic dermatitis among children.

METHODS

The target population of the study was all children participating in health check-up program for 3-year-old children in Tochigi Prefecture in September and October 1997. Using a questionnaire, information on nutrition in infants (breast milk only, bottled milk only, or mixed), parity, mothers' age at birth, and a history of atopic dermatitis was obtained. Besides, data on potential confounding factors were obtained.

RESULTS

Questionnaires from 2,968 children (85.3% of those who were to participate in the programs, and 90.2% of children who participated them) were analyzed. The risk of atopic dermatitis was higher among children with breast milk (odds ratio [OR] = 1.37 with 95% confidence interval [CI] 1.02-1.83) and those with mixed nutrition (OR = 1.21, 95% CI: 0.94-1.57) in comparison with children with only bottled milk. Mothers' age at birth (OR for those who were more than 30 years or older in comparison with those who were younger than 30 years = 1.27; 95% CI, 1.01-1.62) and those with second or later parity orders (OR = 1.32, 95% CI; 1.04-1.67) were also risk factors of the dermatitis after the adjustment for some potential confounding factors.

CONCLUSION

Breast milk elevates the risk of atopic dermatitis slightly; the risk is, however, higher in children in second or later parity orders. If the PCDDs and PCDFs in breast milk cause the dermatitis, this would contradict the assumed metabolism of these chemicals in human bodies.

Swelling and dissolution of silk fibroin (Bombyx mori) in N-methyl morpholine N-oxide

Bombyx mori silk fibers were dissolved in N-methyl morpholine N-oxide (MMNO), an organic cyclic amine oxide used for the solvent spinning of regenerated cellulosic fibers. The commercial MMNO monohydrate used in this study as a solvent for silk is a hygroscopic compound crystalline at room temperature, which becomes an active solvent after melting at 76 degrees C. The degree of hydration of MMNO was checked by DSC measurements. The solvation power of MMNO towards silk fibroin drastically decreased at a water content > or = 20-21% w/w. Dissolution of silk required both thermal and mechanical energy. The optimum temperature was 100 degrees C. At lower temperatures dissolution proceeded very slowly. At higher temperatures, rapid depolymerization of silk fibroin occurred. The value of the Flory-Huggins interaction parameter chi for the MMNO-H2O-silk fibroin system was -8.5, suggesting that dissolution is a thermodynamically favored process. The extent of degradation of silk fibroin was assessed by measuring the intrinsic viscosity and determining the amino acid composition of silk after regeneration with an aqueous methanol solution, which was effective in removing the solvent and coagulating silk. Regenerated silk fibroin membranes were characterized by infrared spectroscopy, differential scanning calorimetry and scanning electron microscopy. The prevailing molecular conformation of silk fibroin chains was the beta-sheet structure, as shown by the intense amide I-III bands at 1704, 1627, 1515, 1260, and 1230 cm(-1). The value of the I1260/I1230 intensity ratio (crystallinity index) was 0.68, comparable to that of the fibers. The DSC thermogram was characteristic of a silk fibroin material with unoriented beta-sheet crystalline structure, with an intense decomposition endotherm at 294 degrees C. The SEM examination of fractured surfaces showed the presence of a dense microstructure with a very fine texture formed by densely packed roundish particles of about 100-200 nm diameter.

Structural and functional analysis of a novel coiled-coil protein involved in Ypt6 GTPase-regulated protein transport in yeast

The yeast transport GTPase Ypt6p is dispensable for cell growth and secretion, but its lack results in temperature sensitivity and missorting of vacuolar carboxypeptidase Y. We previously identified four yeast genes (SYS1, 2, 3, and 5) that on high expression suppressed these phenotypic alterations. SYS3 encodes a 105-kDa protein with a predicted high alpha-helical content. It is related to a variety of mammalian Golgi-associated proteins and to the yeast Uso1p, an essential protein involved in docking of endoplasmic reticulum-derived vesicles to the cis-Golgi. Like Uso1p, Sys3p is predominatly cytosolic. According to gel chromatographic, two-hybrid, and chemical cross-linking analyses, Sys3p forms dimers and larger protein complexes. Its loss of function results in partial missorting of carboxypeptidase Y. Double disruptions of SYS3 and YPT6 lead to a significant growth inhibition of the mutant cells, to a massive accumulation of 40- to 50-nm vesicles, to an aggravation of vacuolar protein missorting, and to a defect in alpha-pheromone processing apparently attributable to a perturbation of protease Kex2p cycling between the Golgi and a post-Golgi compartment. The results of this study suggest that Sys3p, like Ypt6p, acts in vesicular transport (presumably at a vesicle-docking stage) between an endosomal compartment and the most distal Golgi compartment.

On the occurrence of neuronal sprouting in the frontal cortex of a patient with Down's syndrome

We report on the autopsy of a 52-year-old Down's syndrome patient with a 9-year history of progressive dementia. Histologically, there was a marked neuronal loss in the cerebral cortices with numerous neurofibrillary tangles and senile plaques and congophilic angiopathy. The second cortical layer was spongy in appearance and the frontal and temporal white matter showed marked myelin pallor. Immunohistochemistry for MAP2 of the frontal and temporal cortices revealed great reduction in the number of large pyramidal neurons. On the other hand, a much stronger MAP2 immunoreactivity than that seen in the controls was observed in the second layer, which consisted of many small pyramidal neurons with features of aberrant sprouting. They were recognized in the frontal cortices but not in the temporal cortices, and were not immunolabeled with phosphorylated-tau nor MAP5. On double immunolabeling with MAP2 and beta-amyloid antibodies, these neurons were found to be not directly associated with the formation of senile plaques. Ultrastructurally, MAP2 was immunolocalized in an amorphous granular form in the neuronal somata and processes, and paired helical filaments were not immunolabeled. The observation may indicate the occurrence of a remarkable plastic response of small pyramidal cortical neurons in this patient with Down's syndrome.