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Biomedical subjects

N Wada

Publications and source records attributed to N Wada.

At least 37 records · Page 2Linked to original sources

Effects of Carboxylic Acids on the Crystallization of Calcium Carbonate.

The effects of seven carboxylic acids, i.e., acrylic acid, maleic acid, tartaric acid, malic acid, succinic acid, and citric acid, on CaCO(3) crystallization were studied using the unseeded pH-drift method along with a light-scattering technique. Experiments were started by mixing solutions of CaCl(2) and NaHCO(3) in the presence or absence of additives. The crystallization was studied by recording the decrease in pH resulting from the reaction Ca(2+)+HCO(3)(-)-->CaCO(3)+H(+). A given amount of carboxylic acid was added to the solution of CaCl(2) or NaHCO(3) before mixing the reactants. The pH profiles obtained in the case of the CaCl(2) solution containing an additive were similar to those for the NaHCO(3) solution containing one, and when an additive was added after the onset of crystallization, the growth of CaCO(3) immediately stopped. The light-scattering observations, in all cases, indicated that CaCO(3) nucleation occurred at 10-20 s after mixing of the reactants. The results indicated that the nucleation of CaCO(3) was not influenced by the presence of carboxylic acids, but CaCO(3) crystal growth was reduced by their adsorption to the surface of the CaCO(3) crystals. These phenomena were explained by assuming a stronger affinity of the carboxylic acids for CaCO(3) particles than for the free Ca(2+) ions in solution. The crystallization of CaCO(3) in the presence of additives was divided into three stages: nucleation, growth incubation, and growth periods. Copyright 2001 Academic Press.

Journal Article↗

Differential response of Shh expression between chick forelimb and hindlimb buds by FGF-4.

The interactions of Sonic hedgehog (Shh) and fibroblast growth factor (FGF) play important roles in vertebrate limb pattern formation. In the posterior region of the chick limb bud, Shh and FGF-4 each maintain expression in a positive feedback loop. In the anterior region, Shh can also induce Fgf-4 expression in the anterior apical ectodermal ridge. However, the possibility of Shh induction by FGF protein is unclear. Because many experiments to analyze gene expression have been carried out by using the forelimb bud of the chick embryo, we investigated gene expression of the cells in the anterior region of the chick hindlimb bud after FGF-4 application and compared the results with those for the forelimb bud. When an FGF-4-containing bead was implanted into the anterior region of a stage 20 hindlimb bud, ectopic expression of Shh was induced in the mesenchyme beneath the anterior end of the apical ectodermal ridge at 36 hr after implantation. Subsequent to Shh activation, Hoxd13 was also observed in the anterior-distal region of the limb bud. Furthermore, FGF-4 implantation to the hindlimb bud caused additional digit formation accompanying respecification of positional value in the anterior tissue. Ectopic Shh was induced in cells located distal to the FGF-4 bead, and the cells of the flank region did not contribute to ectopic Shh induction. On the other hand, no ectopic Shh and Hoxd13 expression was detected by grafting an FGF-4 bead into the forelimb bud. Although FGF-4 implantation to the forelimb bud occasionally induced extra digit 2 formation, no embryos had an extra digit 3 or digit 4, and many specimens exhibited normal skeletal pattern. These results demonstrate the difference between the fore- and hindlimb buds in the cell competence of Shh induction in response to FGF-4, suggesting the possibility that the responsiveness of mesenchymal cells in signaling molecules is not the same in the fore- and hindlimb buds.

Animals↗

Evaluation of bone metabolic markers in breast cancer with bone metastasis.

PURPOSE: In the present study, four bone metabolic markers were examined to clarify them meaning and clinical value in the detection of bone metastasis (BM) from breast cancer. METHODS: we examined serum carboxyterminal telopeptide of type I collagen (ICTP), tartrate resistant acid phosphatase (TRACP), total alkaline phosphatase (ALP) and urinary type I collagen cross-linked N-telopeptides (NTx) as potential markers. These bone markers were evaluated simultaneously in 156 breast cancer patients; 114 patients without metastasis (group A), 23 patients with BM (group B) and 19 patients with metastasis at sites other than bone (group C). RESULTS: The mean values of ICTP and TRACP in group B were significantly greater than those in group A. Group B consisted of the patients with varying degrees of BM and variation in their treatments. The patients in group B were divided into BM (+) and BM (++) according to hot spots in bone scan. ICTP and TRACP were elevated in BM (++) patients compared to BM (+) patients (p<0.05). The values of ICTP and TRACP of the twelve patients without treatment in group B were significantly higher than those in group A. In the treated patients of group B, the mean values of ICTP and TRACP were lower in responders and cases of stable disease than those with progression. NTx and ALP were inferior to ICTP and TRACP for clinical evaluation of BM. CONCLUSIONS: We confirmed that ICTP and TRACP might be useful markers for screening and monitoring BM in breast cancer.

Acid Phosphatase↗

Neuronal pathways from group-I and -II muscle afferents innervating hindlimb muscles to motoneurons innervating trunk muscles in low-spinal cats.

Synaptic inputs to motoneurons innervating the back and abdominal muscles in the lumbar part of the body from low-threshold hindlimb muscle afferents were studied in unanesthetized low-spinal cats. At a stimulus intensity of 1.2-1.5x threshold (T), which was sufficient to activate only group-I afferents, the incidence of post-synaptic potentials (PSPs) was higher when stimulating proximal muscle nerves than when stimulating distal muscle nerves (e.g., 52% versus 22% for motoneurons innervating m. iliocostalis lumborum: Ilio MNs; 38% versus 18% for motoneurons innervating m. obliquus externus: OEA MNs). At 2-5 T, at which group-II as well as group-I muscle afferents were presumably stimulated, the PSP incidence increased irrespective of nerves stimulated (e.g., 76% for Ilio MNs; 60% for OEA MNs). The minimal central latencies of EPSPs evoked at 1.2-1.5 T ranged 0.8-16.7 ms for Ilio motoneurons and 1.4 -14.2 ms for OEA motoneurons, indicating that the connection between back and abdominal motoneurons and low-threshold afferents from the hindlimb muscle include a monosynaptic one. The latencies of IPSPs were longer and ranged 1.9-18.8 ms for Ilio motoneurons and 2.4-15.8 ms for OEA motoneurons. Input patterns from various hindlimb muscles varied among individual motoneurons, even though they were within the same motoneuron pool. Such synaptic organization seems to differ from that for the leg motoneuron pool. The overall projection pattern of low-threshold afferents from leg muscles to lumbar back and abdominal motoneurons nevertheless suggests that group-I afferent inputs are related to lateral and vertical movements, and that group-II afferent inputs control the stiffness of the trunk.

Afferent Pathways↗

Occurrence of organo-arsenicals in jellyfishes and their mucus.

Water-soluble arsenic compound fractions were extracted from seven species of jellyfishes and subjected to analysis by high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) for arsenicals. A low content of arsenic was found to be the characteristic of jellyfish. Arsenobetaine (AB) was the major arsenic compound without exception in the tissues of the jellyfish species and mucus-blobs collected from some of them. Although the arsenic content in Beroe cucumis, which preys on Bolinopsis mikado, was more than 13 times that in B. mikado, the chromatograms of these two species were similar in the distribution pattern of arsenicals. The nine species of jellyfishes including two species treated in the previous paper can be classified into arsenocholine (AC)-rich and AC-poor species. Jellyfishes belonging to Semaostamae were classified as AC-rich species.

Animals↗

Periodontal ligament cells secrete the factor that inhibits osteoclastic differentiation and function: the factor is osteoprotegerin/osteoclastogenesis inhibitory factor.

The periodontal ligament, a highly specialized connective tissue situated between the tooth and the alveolar bone of the tooth socket, has been thought to influence the remodeling of the alveolar bone. The effects of two human periodontal ligament fibroblastic cell populations (HPLFs) on osteoclast-like cell (OCL) formation and the function of authentic osteoclasts were examined. The addition of the conditioned media (CM) from both HPLF cultures (HPLF-CMs) to mouse bone marrow culture inhibited OCL formation in spite of the presence of 10(-8)M 1alpha, 25 dihydroxyvitamin D3 (1alpha,25(OH)2D3). This inhibitory effect was most remarkable when both CMs were added during day 6 to day 9 following bone marrow culture, just at the late stage of OCL differentiation. HPLF-CMs also induced a significant decrease in the pit area and the pit number formed by authentic osteoclasts on ivory slices. The administration of neutralizing monoclonal antibody (OI-1) against human osteoprotegerin (OPG)/osteoclastogenesis inhibitory factor (OCIF) with HPLF-CMs to mouse bone marrow culture almost completely blocked the inhibitory effect of these CMs on OCL formation. Immunofluorescent examination of HPLF with OI-1 revealed intense positive reactivity in the cytoplasm. Western blot analysis of HPLF-CM using anti-human OPG/OCIF polyclonal antibody resulted in the detection of bands of 60 kDa and 120 kDa which were consistent with those of OPG/OCIF. These results suggest that HPLF cells produce and secrete OPG/OCIF, and that this factor from HPLF prevents the differentiation of the late preosteoclast and the function of the mature osteoclasts.

Adolescent↗

Effect of medetomidine on electroencephalography and use of a quantitative electroencephalograph for evaluating sedation levels in dogs.

This study was designed to characterize the effect of medetomidine (Med) on canine electroencephalography (EEG), to evaluate the use of quantitative EEG for assessing sedation levels and to explore the correlation between the serum concentration of Med and the quantitative EEG. Four groups of dogs were given Med at doses of 20, 40, 80 and 160 microg/kg (Med-20, Med-40, Med-80 and Med-160 groups). Following Med administration, there was synchrony between each unipolar EEG lead. On EEG power spectrum analysis of the bipolar leads, all groups showed a significant depression of the 14-30 Hz components. The power of the 1-3 Hz component in the Med-80 and Med-160 groups was significantly increased, although there were few changes in the other groups. Similar results were obtained from raw data analysis. As a result of quantitative EEG analysis, spectrum edge frequency 90 analysis (SEP90) showed that the frequency was significantly reduced in all groups after Med administration. A dose-response effect was observed in all groups except for the Med-160 group. Both of these EEG analyses were significantly correlated with the serum concentration of Med. However, the result of the SPF90 analysis sugested a stronger correlation than that for median edge frequency analysis. In conclusion, care must be taken in veterinary clinical diagnoses when Med is used during EEG recording, as Med may cause increased activity in the low frequency band and a decrease in high frequency band activity. In addition, quantitative EEG analysis may be useful in assessing the depth of sedation and in further studies on Med administration.

Anesthesia↗

The citrus flavonoid, nobiletin, inhibits peritoneal dissemination of human gastric carcinoma in SCID mice.

The flavonoid nobiletin (5,6,7,8,3',4'-hexamethoxyflavone), found in Citrus depressa Rutaceae, a popular citrus fruit in Okinawa, Japan, reportedly inhibits the production of pro-matrix metalloproteinase (proMMP)-1, 3, and 9 in rabbit synovial fibroblasts in vitro. In the present study, we demonstrated the inhibitory effects of nobiletin on the proliferation of the cancer cell line, TMK- 1, and its production of MMPs. In the SCID mouse model, we found that nobiletin inhibited the formation of peritoneal dissemination nodules from TMK-1. The enzymatic activity of MMP-9 expressed in culture medium obtained from a co-culture of TMK-1 and mouse fibroblastic cells was inhibited by nobiletin in a concentration-dependent manner. In the SCID mouse model, total weight of dissemination nodules was significantly lower in the treated group compared with the vehicle control group (0.07 g vs. 0.78 g, P = 0.0059). The total number of dissemination nodules was also significantly lower than in the vehicle control group (7.5 vs. 69.3 / body, P = 0.0001). These results suggest that nobiletin may be a candidate anti-metastatic drug for prevention of peritoneal dissemination of gastric cancer.

Animals↗

Evaluation of distal and proximal axonal degeneration in patients with carpal tunnel syndrome.

In patients with carpal tunnel syndrome, varying degrees of demyelination and axonal degeneration occur in the median nerve. Only a few studies have examined axonal degeneration produced at proximal to the lesion. In this study proximal axonal degeneration was evaluated and compared with other parameters. In 40 consecutive CTS patient hands, distal latency (DL), compound muscle action potential amplitude (CMAP) and motor conduction velocity (MCV) were analyzed by conventional motor nerve conduction studies. Intrafascicular compound nerve action potential amplitude (N-CNAP) at the elbow after wrist simulation and its nerve conduction velocity (NCV) between wrist and elbow were also analyzed. The negative correlation of DL with CMAP was statistically significant (r = 0.577, p < 0.001). CMAP was correlated with either MCV (r = 0.537, p < 0.001) or N-CMAP (r = 0.710, p < 0.001). A significant correlation of MCV with NCV (r = 0.517, p < 0.001) was also indicated. There were no any other significant correlation among the parameters. In CTS the degree of demyelination and axonal degeneration influence the prognosis for nerve recovery after decompressive surgery. DL is mainly influenced by demyelination that results in conduction block and slowing at the carpal tunnel. CMAP and N-CNAP indicate the degree of axonal degeneration at distal and proximal to the compression site. As in electrophysiologic evaluation of mononeuropathies, proximal axonal degeneration is best assessed by both stimulation and recording electrode locationing proximal to the lesion. Recording of intrafascicular nerve action potential was a little invasive method, but it provided important informations. The negative correlation between DL and CMAP implies that distal axonal degeneration can occur in proportion to the conduction disturbance. Moreover, N-CNAP had a higher correlation with CMAP. The greater the distal axonal degeneration, the more the proximal axonal degeneration. Conduction velocity represents the velocity of the fastest conduction fiber, not the degree of axonal degeneration.

Action Potentials↗

[Prevalence of Martin-Gruber anastomosis on motor nerve conduction studies].

Prevalence of median to ulnar anastomosis in the forearm(Martin-Gruber anastomosis; MGA) to the first dorsal interosseous(FDI), abductor digiti quinti (ADQ) and adductor pollicis(AP) was investigated. Subjects contained 106 patients with normal nerve conduction or patients with various neuropathies. Recording electrodes were placed on the motor point of FDI, ADQ and AP. Supramaximal stimulations were given to the median and ulnar nerves at the wrist or above the elbow. The diagnosis of MGA was made by the following criteria; amplitude of compound muscle action potential(CMAP) increased after elbow stimulation as compared with the wrist stimulation in median nerve conduction studies. The corresponding decrease in CMAP amplitude was found after above elbow stimulation as compared with the wrist stimulation in ulnar nerve conduction studies. No MGA was found in 80(75%) out of 106 patients. MGA to FDI was found in all 26 patients who had MGA. MGA to ADQ and AP was found in 11% and 10% of the patients, respectively. Only 8 out of 26 patients had MGA to all 3 muscles. In the presence of MGA median motor nerve conduction studies demonstrate larger CMAP, with a small initial positivity, after elbow stimulation than after wrist stimulation. And moreover, ulnar motor nerve conduction studies reveal a conduction block-like finding in the forearm. In this study MGA was found in 25% of the patient to FDI, in 11% to ADQ and in 10% to AP. Although a very small MGA might be overlooked in our method, such a small MGA doesn't mislead us into erroneous interpretation of motor nerve conduction studies.

Aged↗

[Innervation pattern to the extensor digitorum brevis by deep peroneal nerve and accessory deep peroneal nerve].

On the electrophysiological basis, extensor digitorum brevis(EDB) muscle is innervated electrophysiologically not only by deep peroneal nerve(DPN) but also by accessory deep peroneal nerve(ADPN), an anomalous branch of superficial peroneal nerve, with a prevalence of 17-28%. We investigated 23 patients who had both DPN and sufficient ADPN innervation to the EDB on the intramuscular distribution of DPN and ADPN innervation to the medial and lateral side of the EDB. Recording electrodes were placed on the medial and lateral edges of the EDB with a supramaximal stimulation to the anterior or lateral ankle, compound muscle action potential (CMAP) of DPN or ADPN innervation was recorded. In 19 patients (83%) the DPN innervation was larger than or equal to the ADPN innervation. Only in 4 patients (17%) the ADPN innervation obviously exceeded the DPN innervation. DPN enters to the EDB from the medial side, and ADPN from the lateral side of the EDB. In 16 patients(70%) the DPN innervation was relatively large and the ADPN innervation was relatively small at the medial side of the EDB, and vice versa at the lateral side of the EDB. These distributions were almost uniform in 5 patients(22%). This study clarified that a biased larger DPN innervation and smaller ADPN innervation to the medial side of the EDB, and vice versa to the lateral side of the EDB in the majority cases. In some cases diffuse innervation to the EDB was found.

Action Potentials↗

[Study on the latency difference between compound muscle and sensory nerve action potentials].

In motor nerve conduction studies compound muscle action potentials (CMAPs) appear later than sensory nerve action potentials (SNAPs). This time lag originates from the conduction delay at the distal motor axon, neuromuscular transmission time and muscle action potential induction time. To investigate the latency difference between CMAPs and SNAPs we studied 46 healthy individuals, 46 patients with diabetes mellitus and 33 patients with carpal tunnel syndrome, using the lumbrical and interossei recording method. In this method the recording active electrode was placed on the 2nd lumbrical muscle and the reference electrode on the proximal palmar aspect of the index finger. Supramaximal stimulation was given to the median or ulnar nerve trunk at 9-cm proximal to the recording active electrode. The CMAP from the 2nd lumbrical muscle (L) and the SNAP from the digital nerve (N) were recorded after median nerve stimulation, and the CMAP from the 2nd interossei muscles (I) was recorded after ulnar nerve stimulation. The residual latency, which is arbitrary defined as the latency difference (L-N) in this study, was 1.38 +/- 0.15 (mean +/- SD) msec in healthy individuals. About 1 msec of the residual latency is regarded as the time for neuromuscular transmission and the time to evoke muscle activities. Thus, the conduction delay at the distal motor axon was calculated as about 0.4 msec in healthy individuals. The residual latency was relatively constant in 29 diabetic patients without conduction delay across the carpal tunnel, which was defined by the latency difference (L-I) < or = 0.4 msec. Their sensory nerve conduction velocities (calculated from N latency) were always above 40 m/sec. On the other hand in diabetic patients with conduction delay across the carpal tunnel, which was defined by the latency difference (L-I) > 0.4 msec, the residual latency gradually increased as the sensory nerve conduction velocity decreased. Their sensory nerve conduction velocities were mostly less than 40 m/sec. The similar relationship was observed in patients with carpal tunnel syndrome without diabetes mellitus. We consider that the diabetic neuropathy alone doesn't cause the increase of the residual latency. Instead, severe conduction delay across the carpal tunnel decreases the N velocity and increases the residual latency. We can also regard the relationship between the latency difference (L-N) and N velocity as being in inverse proportion. Perhaps the increase of the residual latency was simply caused by the proportional decrease in the conduction velocity at the distal motor axon, not by the special mechanism concerning to the carpal tunnel syndrome. This paper presented the electrophysiological changes seen in the distal segment secondary to the proximal entrapment.

Action Potentials↗

[Comparison between Dyck's criteria and the polyneuropathy index-revised (PNI-R) in the electrophysiologic evaluation of diabetic neuropathy].

In Rochester diabetic neuropathy research by Dyck et al., abnormal value in two or more nerves was introduced into the nerve conduction criteria of diabetic neuropathy. Polyneuropathy index-revised(PNI-R) is calculated as the mean percentage of the normal of 8 parameters on the motor nerve conduction studies. They were motor nerve conduction velocities in the forearm or leg segment and F-wave latencies after wrist or ankle stimulation concerning to the median, ulnar, peroneal and posterior tibial nerves. F-wave latencies were adjusted to 160 cm height and used reciprocals in comparison with normal values. To compare these two indices, first we obtained the normal limit(1st or 99th percentile value) of each parameter from the data of 62 healthy individuals. Then in 78 patients with diabetes mellitus number of abnormal nerves and the PNI-R were investigated. Abnormal values were frequently observed in the categories of motor nerve conduction velocities and F-wave latencies. Amplitude of compound muscle action potential (CMAP) or sensory nerve action potential(SNAP) in each nerve had a large standard deviation. In such parameters abnormal rate was extremely low, because the lower limit of normal being very small. Nevertheless, sigma CMAP which means the summation of amplitudes of 3 CMAPs had as high as 53% of abnormal rate. The coefficient of correlation between number of abnormal nerves and the value of PNI-R mounted up to -0.87. Instead, the coefficient of correlation of sigma CMAP or sigma SNAP, which means the summation of amplitudes of ulnar and sural SNAPs, with PNI-R were 0.65 and 0.79, respectively. In 14 patients PNI-R was normal and the number of abnormal nerves was 0 or 1. In 59 both categories were abnormal, and only in 5 they were not coincide. As to the clinical signs PNI-R had better correlation than number of abnormal nerves with vibration threshold or degree of Achilles tendon reflex. sigma CMAP is a convenient index to detect the existence and the degree of neuropathy. This index expresses the degree of neurogenic muscular atrophy, though it doesn't always advance parallel to the decrease in number of motor nerves. sigma SNAP had higher coefficient of correlation with PNI-R or number of abnormal nerves than sigma CMAP. In conclusion, abnormal PNI-R and abnormal value in two or more nerves are both useful and coincide with each other in the detection of diabetic neuropathy. The PNI-R is an excellent quantitative index, and the PNI-R corresponds well with the number of abnormal nerves. These observations indicate that the number of nerves with abnormal value is also available as a simple and semi-quantitative index of diabetic neuropathy.

Adult↗

Slippage of nonsuperfluid helium films

We measured the mechanical response of 3He and 4He films on an oscillating substrate using an ultrasonic technique. Up to the coverage at which the fluid state appears at absolute zero, a part of the nonsuperfluid 3He and 4He films underwent slipping relative to the substrate at low temperatures. From the temperature dependence of the slippage, it was found that a thermally activated process plays an important role in the frictional force of this system.

Journal Article↗

Immunohistochemical detection of p53 and p21 proteins in canine testicular tumours.

The objective of this study was to detect by immunohistochemical means nuclear accumulations of p53 and p21 proteins in testicular tumours of dogs. Intense p53 protein nuclear labelling was shown by each of seven seminomas and one intermediate collision tumour. Moderate or intense immunoreactivity was shown by three Sertoli cell tumours. All the tumours also showed p21 nuclear reactivity in parallel with the p53 reactivity. In contrast, four Leydig cell tumours showed no detectable immunoreactivity. The results suggested that high levels of p53 accumulation were associated with the expression of wild-type p53, which was able to activate the transcription of the p21 gene. In addition, weak p53- and p21-nuclear reactivities were detectable in primary spermatocytes within normal seminiferous tubules.

Animals↗

Identification of chick frizzled-10 expressed in the developing limb and the central nervous system.

We have identified chick frizzled (Fz)-10, encoding a Wnt receptor, and examined the expression pattern during embryogenesis. Fz-10 is expressed in the region posterior to the Hensen's node at stage 6. Fz-10 expression is detected in the dorsal domain of the neural tube and the central nervous system of the developing embryo. In the developing limb, Fz-10 expression starts at stage 18 in the posterior-dorsal region of the distal mesenchyme, and gradually expands to the anterior-distal region. Fz-10 is also expressed in the feather bud and branchial arch. Implantation of Sonic hedgehog (Shh)-expressing cells into the anterior margin of the limb bud resulted in the induction of Fz-10 expression in anterior-dorsal mesenchyme.

Amino Acid Sequence↗

Fatal hypertrophic cardiomyopathy associated with an A8296G mutation in the mitochondrial tRNA(Lys) gene.

We describe an 8-day-old baby girl presenting a fatal infantile form of hypertrophic obstructive cardiomyopathy, associated with an A8296G mutation in the mitochondrial tRNA(Lys) gene. She was born from a healthy unrelated couple, and was the first infant of dizygotic twins. Soon after birth, she was noted to have tachypnea and generalized hypotonia. She had high levels of lactate and pyruvate, and was diagnosed as having hypertrophic cardiomyopathy using echocardiography. She died by cardiac failure. Mitochondrial DNA analysis was performed by sequencing after PCR-subcloning methods, and the percentage of mutation was measured using PCR-RFLP methods. In various tissues obtained at autopsy, analysis showed a heteroplasmic population of A8296G mutation in the mitochondrial tRNA(Lys) gene in all the tissues examined. Maternal inheritance was demonstrated in the family members. Our data demonstrated that an A8296G mutation in the mitochondrial tRNA(Lys) gene showed clinical heterogeneity from a milder form previously reported as mitochondrial diabetes mellitus, to a more severe form as hypertrophic obstructive cardiomyopathy, according to the spatial distribution of this mutation. Hum Mutat 15:382, 2000.

Cardiomyopathy, Hypertrophic↗