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Biomedical subjects

N Wada

Publications and source records attributed to N Wada.

At least 73 records · Page 4Linked to original sources
PubMed2000

Spinal projections of cat primary afferent fibers innervating caudal facet joints.

The spinal projections of afferent fibers innervating the facet joints between caudal vertebrae were examined by the use of anterograde transport of wheat germ agglutinin-horseradish peroxidase (WGA-HRP). Experiments were performed on 5 adult cats in which spinal dorsal roots below the 2nd sacral segment (S2) on the right side were cut. Injections of WGA-HRP into the caudal facet joints gave rise to extensive cranio-caudal distribution of WGA-HRP positive products along the spinal cord, indicating that many afferent fibers innervating unilateral facet joints terminate bilaterally in laminae I-II, V-VI and X of the thoracic, lumbar, sacral and caudal spinal cord. These afferent fibers may convey a series of sensory information from the caudal facet joints to the spinal cord.

Afferent Pathways↗
PubMed2000

Phosphorylation of 13 kDa nuclear protein in hepatocarcinomas induced by peroxisome proliferators.

Peroxisome proliferators (PPs) are nongenotoxic compounds causing the emergence of hepatocellular carcinoma in rodents, but the mechanisms of the hepatocarcinogenesis have been unclear. The authors examined the changes in phosphorylation of nuclear proteins after treatment with (4-chloro-6-[2,3-xylidino]-2-pyrimidinylthio) acetic acid (Wy-14,643). Wy-14,643 (0.1% w/w in diet) was given orally to male F-344 rats for up to 80 wk. In the hepatocarcinomas induced by Wy-14,643, phosphorylation of 13 kDa nuclear protein (NP 13), which was resistant to alkaline treatment, was significantly increased. NP 13 phosphorylation gradually increased, dependent on treatment period. Furthermore, in the hepatocarcinomas induced by other PP, di(2-ethylhexyl)phthalate, increase in NP13-phosphorylation was also observed. Therefore, NP 13-phosphorylation may relate to development of preneoplastic or neoplastic lesions induced by PPs.

Animals↗
PubMed2000

[Quantitative changes of elastin, fibrillin and collagen in abdominal aortic aneurysms].

To examine quantitative changes of elastin, fibrillin and collagen in abdominal aortic aneurysms, including ruptured abdominal aortic aneurysms (RAAA), inflammatory abdominal aortic aneurysms (IAAA) and abdominal aortic aneurysms (AAA) were measured. Items measured included the desmosine content of the aorta (desmosine 1) or of the elastin fraction (desmosine 2), fibrillin content in the aorta, hydroxyproline in the aorta, collagen percent and elastin percent, and were compared with control samples from the nonaneurysmal aortic segments. The elastin contents (desmosine 2) in RAAA, IAAA and AAA were significantly lower than those of controls. The content of the desmosine 2 from IAAA and AAA did not show a negative association with Ca. The fibrillin contents of the aorta from RAAA, IAAA and AAA were significantly higher than those of controls. The collagen content in the RAAA aorta was significantly higher than that of controls. There was a correlation of the ratio of fibrillin to elastin components (fibrillin/desmosine 1 or fibrillin/desmosine 2 or fibrillin/elastin%) and the ratio of collagen to elastin components (collagen/desmosine 1 or collagen/desmosine 2 or collagen/elastin%). These results indicated that increasing fibrillin and collagen might be a complementary result of decreasing elastin crosslinks in the aorta. This phenomenon was markedly in RAAA.

Aged↗
PubMed2000

[Analysis of segmental motor conduction in the median and the ulnar nerves: comparison between normal and diabetic individuals].

We investigated characteristics of segmental motor conduction in the median and the ulnar nerves. Subjects were 55 individuals with normal conduction of the upper extremity and 71 patients with diabetes mellitus. Mean polyneuropathy index (PNI), which was determined as a mean percentage of the normal for 6 indices concerning to the conduction velocity in the upper limb, was 99.0% in the normal group and 85.6 % in the diabetic group on the mean. In the normal group distal latency was longer in the median nerve than in the ulnar nerve, and the conduction time between Erb's point and the wrist was longer in the ulnar nerve than the median nerve both in men and women. In the diabetic group these differences were accentuated; that means the distal latency was relatively more prolonged in the median nerve and the conduction time between Erb's point and the wrist was much longer in the ulnar nerve. Prolonged distal latency in the median nerve of women and conduction delay between Erb's point and the wrist in the ulnar nerve of men altogether resulted in the gender difference in the median minus ulnar F-wave latency after wrist stimulation in the diabetic group. Carpal tunnel segment of the median nerve and the elbow segment of the ulnar nerve are known to be common entrapment sites. This phenomenon of accentuated conduction delay in these common entrapment sites might be considered as a sort of 'double crush syndrome'.

Diabetes Mellitus↗
PubMed2000

An intracellular study of pudendal afferent inputs onto tail motoneurons in the spinalized cat.

Postsynaptic potentials, elicited by stimulation of the sensory pudendal (SPud) and superficial perineal nerves (SPeri) on both sides, were recorded from motoneurons innervating tail muscles in the non-anaesthetized and spinalized cat. The stimulation of SPud and SPeri on both sides predominantly produced excitatory postsynaptic potentials (EPSPs) in all kinds of tail motoneurons (70-95%). The inhibitory postsynaptic potentials (IPSPs) were often observed in motoneurons innervating ventral tail muscles (30-33%). The means of averaged central latencies of EPSPs and IPSPs ranged from 4.3 to 7.3 ms, and from 4.6 to 8.4 ms, respectively. The findings suggests that polysynaptic neuronal pathways from pudendal nerve to tail motoneurons produce tonic activities of all tail muscles to raise the tail in micturation, defecation and sexual movements which are induced by stimulation of pudendal nerves.

Animals↗
PubMed2000

[Sequential nerve conduction studies in a patient with ulnar neuropathy at the elbow treated by night athletic supporter].

Ulnar nerve can be stretched with the elbow flexed position. To avoid elbow flexed position in patients with ulnar neuropathy at the elbow we used an athletic elbow supporter. We herein demonstrate a 31-year-old man with right ulnar neuropathy at the elbow whose neuropathy was resolved by using this supporter only at night. He had complained of weakness and paraesthesia in the ulnar side of his right hand. Nerve conduction studies of right ulnar nerve revealed decrease in the amplitude of compound nerve action potentials and a severe motor nerve conduction block with apparent conduction delay around the ulnar groove. A diagnosis of ulnar neuropathy at the elbow was done and we recommended him to wear an athletic elbow supporter at night. Paraesthesia of his right hand improved in a few days after starting this therapy. Three months later paraesthesia was resolved. One year later grip power of his right hand increased to 35 kg from 20 kg, and the conduction block at the elbow completely disappeared. Compound nerve action potentials, recorded at the segment of wrist to above elbow and wrist to finger, were improved equally. These observations suggest that the conduction block at the elbow entrapment site and the distal axonal degeneration gradually recovered together.

Elbow↗
PubMed2000

[A case of gastric cancer with multiple liver metastasis responding to combined chemotherapy with low-dose cisplatin and 5-fluorouracil].

A 68-year-old man who had Borrmann type 4 gastric cancer with multiple liver metastases was admitted to our hospital on October 20, 1998. He was considered nonresectable and placed on neoadjuvant chemotherapy consisting of low-dose CDDP and 5-FU. After 9 weeks of administration, the liver metastases had disappeared on abdominal computed tomography, but the primary lesion had progressed. On May 12, 1999, a total gastrectomy with a partial resection of the transverse colon and resectional biopsy of a white nodule of the liver were performed. This was a non-curative operation because of the peritoneal dissemination. A histopathological examination of the liver nodule revealed that the cancer cells had disappeared. The patient had an uneventful postoperative course and 4 weeks of chemotherapy were added. He remains alive with no symptoms or re-growth of the liver metastatic tumor 4 months after the surgery.

Adenocarcinoma↗
PubMed2000

[Randomized comparative study of CMF (cyclophosphamide, methotrexate and 5-fluorouracil) and UFT-tamoxifen regimens as adjuvant chemotherapy after surgery for breast cancer: Tochigi Prefectural Study Group for Post-Breast Cancer Adjuvant Chemotherapy].

This prospective randomized study aimed at establishing the optimal postoperative adjuvant chemotherapy regimen for premenopausal n+ breast cancer patients. The treatments were Regimen A, comprising 6 courses of CMF (cyclophosphamide, 100 mg/body on days 1-14; methotrexate, 40 mg/m2 on days 1 and 8; and 5-fluorouracil, 500 mg/m2 on days 1 and 8), and Regimen B, consisting of UFT (300 mg/day) and tamoxifen (30 mg/day) administered orally each day for 2 years. Telephone registration allocated the patients to the treatment groups by the minimization method in relation to the T category, number of n+ lesions and estrogen receptor status. Forty-five patients were registered, and 44 of them were eligible (22 cases each to Regimen A and Regimen B). The principal background factors showed no biases between the groups. The adverse reaction incidence was significantly higher with Regimen A (90.9% vs 22.7%). The 5-year survival rate was 89.8% with Regimen A and 100% with Regimen B, while the 5-year disease-free rates were 64.5% and 76.3%, showing no statistical significance. Regimen B showed a better QOL rating after 6 months of therapy in relation to nausea-vomiting and hair loss, and after 24 months in relation to appetite, sleep, performance status, happiness, anorexia and hair loss.

Adult↗
PubMed2000

Electromyographic and kinematic studies of tail movements during falling in cats.

When falling from an inverted position, EMG activities of tail muscles (the m. extensor caudae lateralis, m. abductor caudae externus, m. flexor caudae longus) and tail movements were recorded in 7 long-tailed adult cats. After being released from an elevated position, cat rotates the tail in a reverse direction to rotation of other parts of the cat's body then lands on four legs. Rotation of the tail was started by EMG activities of the tail muscles on one side. Both synchronized and alternating groups of discharge occur between its left and right side, while extensor and flexor movements and displacements of its tail appear in the air. After transection of ventral roots from the coccygeal spinal segments innervating tail muscles, cats often fail to land on four legs. These facts suggest that that tail movements control body balance in the air when falling from an inverted position.

Animals↗
PubMed2000

Size-dependent flowering behavior and heat production of a sequential hermaphrodite, Symplocarpus renifolius (Araceae).

We examined the flowering performance in a population of the protogynous perennial herb Symplocarpus renifolius (Araceae), with special consideration of plant size. Flowering of S. renifolius occurred in very early spring, soon after snow melt. The spadices generated heat throughout the pistillate (female) and bisexual phases, but heat production decreased quickly after the beginning of the staminate (male) phase. During the flowering season, the sex ratio within the population dramatically changed from a dominance of females to a dominance of males. The duration of the female phase was negatively correlated with the onset time of flowering, and the duration of the male phase was positively correlated with plant size. Larger plants began blooming earlier, produced more heat, made the transition from female to male phase more rapidly, and lasted longer as males than smaller ones. Such size-dependent flowering performance caused unidirectional pollen flow from large to small plants. The number of seeds produced per spadix was positively correlated with the duration of the female phase, although it was not correlated with plant size. However, the estimated number of seeds sired during the male phase was positively correlated with plant size. Early flowering, rapid gender change, and higher heat production of the spadices by larger plants were factors considered to promote the higher success of the male function without decreasing the success of the female function.

Journal Article↗
PubMed2000

[Sensory nerve action potentials in the evaluation of diabetic polyneuropathy].

In order to clarify the suitability of sensory nerve action potential(SNAP) in the evaluation of diabetic polyneuropathy, we studied measurements of SNAPs in the median, ulnar and sural nerves. Subjects were 253 patients with non-insulin dependent diabetes mellitus; 167 men and 86 women, aged 58.2 +/- 12.8(mean +/- SD) years old. Their diabetic history was 10.2 +/- 8.6 years. SNAPs were recorded antidromically from index finger, little finger and lateral to the Achilles tendon, respectively. Twenty-eight patients, in whom any one of the SNAPs couldn't be obtained, were already excluded from this study. The polyneuropathy index (PNI) was calculated from 12 indices concerning to the velocity or long distance latency in motor nerve conduction studies of 4 nerves. The PNI is known to be an excellent index to express the degree of diabetic polyneuropathy. Amplitude and conduction velocity in each nerve was 28.6 +/- 15.6 microV and 46.2 +/- 7.4 m/sec in the median nerve, 26.7 +/- 15.8 microV and 47.0 +/- 6.5 m/sec in the ulnar nerve, 13.1 +/- 6.5 microV and 43.1 +/- 6.0 m/sec in the sural nerve, respectively. The coefficient of correlation of the measurements between median and ulnar nerves was larger than other assortment of nerves. The coefficient of correlation of each measurement with PNI was around 0.40 in the amplitude and around 0.55 in the conduction velocity. Nevertheless, the mean value of the 3 nerves had a higher coefficient of correlation with PNI; 0.48 in the amplitude and 0.60 in the conduction velocity. SNAP measurements of a single nerve are often largely affected by the inter-individual differences, inter-nerve differences or measuring errors. But the mean value of the 3 nerves will be better in exploring the degree of diabetic polyneuropathy. Evaluation of diabetic polyneuropathy by SNAPs will be best achieved by using the mean value of these 3 nerves.

Action Potentials↗
PubMed2000

[Comparison of nerve conduction studies between conventional and lumbrical/interossei recording methods in diabetics].

Median nerve conduction studies were performed by conventional and lumbrical/interossei recording methods. The former is composed of recordings of compound muscle action potential from abductor pollicis brevis (APB) and sensory nerve action potential from second digit (D) after wrist stimulation. In the latter the recording electrode was placed lateral to the midpoint of the 3rd metacarpal bone, and recorded compound muscle action potential from the 2nd lumbrical (2 L) and sensory nerve action potential from the digital nerve (N) after wrist stimulation. Subjects were 57 healthy individuals and 97 patients with diabetes mellitus. Particularly in diabetic patients values of coefficient of correlation between each measurement were high enough; i.e., r = 0.91 between latencies to 2 L and APB, r = 0.55 between amplitudes of 2 L and APB, r = 0.86 between amplitudes of N and D. Corresponding measurements by conventional method and lumbrical/interossei method were identical in the values of coefficient of correlation between measurements. The characteristics of lumbrical/interossei method are to be able to record compound muscle action potentials and nerve action potential from the same electrode. In this study values obtained by lumbrical/interossei method showed identical correlation between measurements to the corresponding ones by conventional method. In conclusion recordings of APB and D by conventional method can be replaced with the recordings of 2 L and N by lumbrical/interossei method in the evaluation of diabetic neuropathies.

Action Potentials↗
PubMed2000

[Isolated extensor digitorum brevis involvement in the population of normal systemic nerve conduction velocities].

To investigate the characteristics of isolated atrophy in extensor digitorum brevis(EDB), we analysed 262 patients whose polyneuropathy index(PNI) was 90% or more than the normal mean value. The PNI was determined as the mean percentage of the normal in 12 indices concerning to the velocity or long distance latency in motor nerve conduction studies. Latencies were adjusted to 160 cm height. Amplitude of compound muscle action potential (CMAP) in EDB showed no correlation with the patient's age. Similar result was obtained as well when studied in 115 patients whose PNI level was 95% or more than the mean normal value. In 18(7%) out of 262 patients CMAP amplitude in EDB was 1 mV or less; larger prevalence(p < 0.05) in women(10%) than in men(4%). The number of motor units which innervate EDB decreases along with the age, but this age-related change could be compensated by the magnification of each motor unit. In Western reports isolated EDB palsy has a predilection for emaciated men. Instead, our results showed the predominance in women. We may have some factors other than in Western countries, for example customs to sit directly on the mat for a long time, in the occurrence of isolated EDB palsy. In conclusion, amplitude reduction in EDB CMAP may reflect the following two factors; neuropathy-related factor and another factor independent of age or neuropathy.

Action Potentials↗
PubMed1999

Effects of Carboxylic Acids on Calcite Formation in the Presence of Mg2+ Ions.

The effects of seven carboxylic acids on calcite formation in the presence of Mg2+ ions, whose molar concentration ratio Mg2+/Ca2+ = 0.5 exclusively induced aragonite precipitation in the absence of carboxylic acids, were studied using a double diffusion technique. The presence of carboxylic acids, acrylic acid, maleic acid, tartaric acid, malonic acid, malic acid, succinic acid, and citric acid in the gel medium favored the formation of magnesian calcite relative to the amount of the additives. Induction time and the positions of the first precipitation were measured to analyze the behavior of crystallization based on the equivalency rule. The formation of magnesian calcite was also studied with the help of Avrami's equation (solid-state model for transformation). The results of applying this equation suggested that aragonite transformed into calcite through a solid-to-solid process. The formation of magnesian calcite was interpreted as the following process: aragonite nuclei, formed owing to Mg2+ ions at the initial stage of CaCO3 crystallization, transformed into calcite nuclei through a solid-to-solid process while their growth was inhibited by the adsorption of carboxylic acids. The magnesian calcite crystals grew on crystal seeds of calcite formed from aragonite nuclei. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

Postoperative changes in thyrotropin-binding inhibitory immunoglobulin level in patients with Graves' disease: is subtotal thyroidectomy a suitable therapeutic option for patients of childbearing age with Graves' disease?

Thyroid-stimulating hormone (TSH)-binding inhibitory immunoglobulin (TBII) is thought to be one of the essential causes of Graves' disease, and most cases of neonatal hyperthyroidism can be explained by transplacental passage of TBII. Because surgery is often indicated for patients of childbearing age, it is important to elucidate how surgery reduces TBII levels. Between 1988 and 1991 a total of 946 female patients with Graves' disease underwent subtotal thyroidectomy. Follow-up examination was undertaken at 1, 2, 3, and 4 to 5 years after surgery. At 4 to 5 years after surgery, 76.8% of patients without recurrent overt hyperthyroidism had TBII < 20%. In patients with recurrent hyperthyroidism, TBII increased gradually during follow-up, and they had higher TBII levels than nonrecurrence patients. There were a few euthyroid and hypothyroid patients who had TBII > 60%, and the number of such patients decreased annually. In most of the patients, immunologic remission was obtained by subtotal thyroidectomy except for their having recurrent hyperthyroidism. To acquire immunologic remission, hormonal remission, at least, would be necessary. Because no definite factor other than the size of the thyroid remnant related to postoperative thyroid function was elucidated, near-total thyroidectomy rather than subtotal thyroidectomy is expected to be induced not only hormonal remission but also immunologic remission. It should be noted that a few patients achieved hormonal remission but not immunologic remission.

Adult↗
PubMed1999

Neuronal pathways for spinal reflexes activated by group I and group II muscle afferents in the spinal segment (Co1) innervating the tail in the low spinalized cat.

We studied neuronal pathways for spinal reflexes activated by group-I and group-II muscle afferents in the spinal segments innervating the tail in unanesthetized and spinalized (L1) cats. Experiments were performed on 25 adult cats of both sexes. The effects of stimulating nerves innervating six tail muscles on both sides were recorded from tail motoneurons in the first coccygeal spinal segment (Co1) using glass microelectrodes. Stable recordings were obtained from 150 tail motoneurons. Stimulation of group-1 muscle afferents (stimulus intensity <1.8 T) often produced EPSPs (82/150) after stimulating nerves innervating neighboring tail muscles. Motoneurons innervating the long-tendoned muscles, M. extensor caudae lateralis and M. flexor caudae longus (ECL and FCL), received heteronymous monosynaptic connections from group-I muscle afferents innervating the ipsilateral tail muscles. The motoneurons innervating segmental muscles, M. extensor caudae medialis and M. flexor caudae brevis (ECM and FCB), received heteronymous monosynaptic connections from group-I muscle afferents innervating tail muscles on both sides. The motoneurons innervating tail muscles originated from the Ossa coxae, M. abductor caudae externus and M. abductor caudae internus (ACE and ACI), received monosynaptic connection from group-I muscle afferents innervating most of the tail muscles on both sides. Crossed disynaptic inhibitory pathways activated by primary muscle afferent inputs were observed in ECM, ACE, FCL, and FCB motoneurons. The effects of group-II afferent inputs were not dependent on the kind of motoneuron, and alternative excitatory and inhibitory pathways were not clearly observed in the tail motoneuron pool. It is suggested that variability of the neuronal pathways from group-I and -II muscle afferents to tail motoneurons corresponds to functional relationships among tail muscles, depending on the tail movements.

Animals↗
PubMed1999

Neuronal pathways from low-threshold hindlimb cutaneous afferents to motoneurons innervating trunk muscles in low-spinal cats.

Postsynaptic potentials (PSPs) evoked in motoneurons innervating the back and abdominal muscles in the lumbar part of the body by stimulating hindlimb cutaneous afferents were investigated in unanesthetized decerebate and spinal cats. Various types of PSP: pure excitatory postsynaptic potential (EPSP), pure inhibitory postsynaptic potential (IPSP), and mixed PSP (i.e., EPSP followed by IPSP, EPSP/IPSP; and IPSP followed by EPSP, IPSP/EPSP) were observed. The weak stimulation at 2 times threshold (2T) produced predominantly the EPSP, while at 5T the incidence of IPSP or EPSP followed by IPSP was increased. In about 20-50% of the various groups of motoneurons, PSPs evoked by ipsi- and contralateral nerves were qualitatively and quantitatively similar. For the other motoneurons, PSPs evoked by ipsi- and contralateral nerves were markedly different with respect to magnitude and/or polarity. These findings suggest that, within each motoneuron pool, some neurons act to increase stiffness of the trunk or to move vertically in response to an increased activity of cutaneous afferents, while the other motoneurons act to produce lateral bending of the trunk.

Afferent Pathways↗