Search PubMed⌕ Search

Biomedical subjects

K Abe

Publications and source records attributed to K Abe.

At least 1,009 records · Page 56Linked to original sources
PubMed1996

Founder effect in spinal and bulbar muscular atrophy (SBMA).

We analyzed the polymorphic (CAG)n and (GGC)n repeats of the androgen receptor gene in 113 unrelated X-linked spinal and bulbar muscular atrophy (SBMA) X chromosomes and 173 control X chromosomes in Japanese males. The control chromosomes had an average CAG repeat number of 21 +/- 3 with a range from 14-32 repeat units, and SBMA chromosomes had a range from 40-55 with a median of 47 +/- 3 copies. The control chromosomes had seven different alleles of the (GGC)n repeat with the range of 11 to 17; the most frequent size of (GGC)n was 16 (79%), while (GGC)17 was very rare (1%). However, in SBMA chromosomes only two alleles were seen; the most frequent size of (GGC)n was 16 (61%) followed by 17 (39%). (GGC)n size distribution was significantly different between SBMA and control chromosomes (P < 0.0001), indicating the presence of linkage disequilibrium. There was no allelic association between the (CAG)n and (GGC)n microsatellites among control subjects as well as SBMA patients, which suggests that a founder effect makes a more significant contribution to generation of Japanese SBMA chromosomes than new mutations.

Genetic Linkage↗
PubMed1996

Diagnostic utility of endoscopic ultrasonography for preoperative rectal cancer staging estimation.

The preoperative staging accuracy of endoscopic ultrasonography (EUS) was assessed in 38 rectal cancer patients who underwent rectal EUS and curative surgery from July 1992 to September 1994. We used a GF-UM20 instrument with both 12- and 7.5-MHz transducers. Compared with the histological findings, the diagnostic accuracy rate for EUS was 76% (29/38) for the invasion depth and 85% (sensitivity) and 72% (specificity) for level one lymph node metastasis, resulting in an overall preoperative staging accuracy of 74% (28/38). The diagnostic accuracy of invasion depth was poor (only 45%: 5/11) in cases shown histologically to be a1 (tumor invasion through muscularis propria into parietal fat), but ranged from 90 to 100% when the a1 cases were excluded. The diagnostic accuracy for level one lymph node metastasis was proportional to the nodal size. The size of lymph nodes that had been diagnosed as metastatic and non-metastatic (P < 0.05) differed significantly. Eighteen (86%) of the 21 metastatic nodes with histologically massive invasion were detected preoperatively by EUS. Eight of the 11 undetected metastatic nodes were either less than 4 mm in diameter or showed only slight invasion. Most (81%) of the level one metastatic nodes larger than 5 mm were found. The worst preoperative staging diagnostic accuracy was for stage II cases (63%: 5/8), and in four of the 10 misdiagnosed cases, the stage was underestimated due to slight nodal invasion or skip metastasis (2 cases each). Although it was difficult to diagnose nodal metastasis correctly in these cases, preoperative staging using EUS was considered useful for diagnosing almost 80% of our rectal cancer cases.

Humans↗
PubMed1996

Phosphorylation of a protein (pp56) is related to the regeneration of rice cultured suspension cells.

Short-term cultured suspension cells of rice (Oryza sativa L.) are capable of regeneration, but not in long-term culture. For clarification of the mechanism of regeneration, protein phosphorylation in short-term and long-term cultured suspension cells was compared by two dimensional-polyacrylamide gel electrophoresis. A 56 kDa protein having an isoelectric point of 4.5 was phosphorylated in vitro in short-term cultured suspension cells, but was not phosphorylated after regeneration. This protein in long-term cultured suspension cells remained phosphorylated after transfer to the regeneration medium. However, using an antibody raised against this protein from short-term cultured suspension cells, it was always detected in long-term and short-term cultured suspension cells after transfer to the regeneration medium. The partial amino acid sequence of the HPLC-purified protein showed homology to a calcium-binding protein from maize. The phosphorylation of the 56 kDa protein (pp56) appears to be associated with the regeneration of cultured rice cells.

Amino Acid Sequence↗
PubMed1996

Basaloid-squamous carcinoma of the esophagus. A clinicopathologic, DNA ploidy, and immunohistochemical study of seven cases.

Basaloid-squamous carcinoma (BSC) of the esophagus is a rare but interesting neoplasm that occurs primarily in the upper aerodigestive tract. In this study, we reviewed 371 cases of esophageal malignancies and detected seven cases (1.9%) of BSC. The clinicopathologic features, light and electron microscopic findings, and immunohistochemical localization of various differentiation-related antigens, including cytokeratin (CK) subtypes, p53, and epidermal growth factor receptor (EGFR), were examined. DNA ploidy was also determined in an effort to characterize the biologic features of these tumors. The tumors were classified as stage I (n = 1), IIB (n = 3), III (n = 2) or IV (n = 1). Six patients had lymph node metastasis, in four the metastatic carcinoma exhibited basaloid components. Histologically, all the tumors displayed a biphasic pattern of basaloid and squamous components. The former predominated in three cases, the latter in four cases. All the tumors contained solid growth of basaloid cells with microcystic patterns and stromal hyalinosis as well as palisading of cells. Ultrastructurally, markedly replicated basement membrane was observed. Immunohistochemistry revealed staining with only CK 14 and CK 19 antibodies in the periphery of the basaloid tumor nests. These antibodies were also positive in the basal layer of normal esophagus. Diffuse immunoreactivity for EGFR was demonstrated in all the tumors. Five tumors displayed p53 nuclear immunoreactivity. All of the basaloid components demonstrated aneuploidy by DNA image cytometry. We conclude that BSC is a distinct type of esophageal carcinoma that should be differentiated from the usual types of esophageal carcinoma and may be associated with aggressive biologic behavior.

Aged↗
PubMed1996

Effects of benidipine, a calcium antagonist, on urinary kallikrein excretion and renal impairment in experimental diabetes.

OBJECTIVE: To assess the long-term effects of different antihypertensive agents on urinary protein excretion and kallikrein excretion in diabetic rats with renal impairment. METHODS: Uninephrectomized streptozotocin diabetic Wistar-Kyoto rats were randomly assigned to receive vehicle, a calcium antagonist (benidipine) or an angiotensin converting enzyme inhibitor (captopril) for up to 12 weeks. Active kallikrein was determined by its kininogenase activity, and generated kinins were measured by radioimmunoassay. Total kallikrein was also determined by measuring kininogenase activity after inactive kallikrein had been activated with trypsin. RESULTS: Urinary protein excretion increased significantly in diabetic rats compared with non-diabetic rats. Urinary active kallikrein excretion was significantly reduced in diabetic rats, whereas urinary total kallikrein excretion was unchanged, resulting in a reduced percentage of active to total kallikrein compared with that in non-diabetic rats. Benidipine and captopril reduced blood pressure and attenuated the development of diabetic renal impairment in a similar manner. However, only benidipine attenuated the decreases in urinary active kallikrein excretion and the ratio of active to total kallikrein in diabetic rats. CONCLUSIONS: Although pathophysiological relevance of impaired urinary kallikrein activation to the development of diabetic renal impairment remains to be determined, our result might suggest a new mechanism by which calcium antagonists protect the kidney from diabetic renal impairment.

Analysis of Variance↗
PubMed1996

Bilateral sensorineural hearing loss associated with the point mutation in mitochondrial genome.

Mitochondrial DNA (mtDNA) mutation associated with sensorineural hearing loss (SNHL) has previously been described in MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes) and in aminoglycoside-induced deafness. The authors of this study report three cases of SNHL associated with mtDNA mutation (3243A-->G). They examined the clinical features of this type of SNHL by audiologic studies and examined the mtDNA mutation by the polymerase chain reaction technique. In the three cases described, the SNHL had an adult onset and was bilateral and symmetrical. All patients had adult-onset diabetes mellitus. Audiologic studies revealed that the SNHL in all patients derived from the cochlea rather than from retrocochlear sites. It is presumed that mtDNA mutation results in mitochondrial dysfunction in cochlear tissues (i.e., hair cells and stria vascularis) and in neurons of the auditory pathway. Genetic analysis of mtDNA offers new insight into the diagnosis and treatment of SNHL.

Adolescent↗
PubMed1996

Adenosylcobalamin-dependent methylmalonyl-CoA mutase isozymes in the photosynthetic protozoon Euglena gracilis Z.

The photosynthetic protozoon Euglena gracilis Z contains adenosylcobalamin-dependent methylmalonyl-CoA mutase (MCM) involved in propionate metabolism. The specific activity of the Euglena mutase was about 6.5-fold greater in propionate-adapted Euglena cells than in photoautotrophic cells (control). Although the control cells contained only one mutase (apparent M(r) 72,000), the propionate-adapted cells contained two mutases with M(r) values of 72,000 and 17,000; both enzymes were located in the mitochondria. These results provide evidence that propionate-adapted Euglena contains two MCM isozymes. The induced mutase (M(r) 17,000) permits photoassimilation of propionate.

Animals↗
PubMed1996

Significance of IL-1beta and IL-1 receptor antagonist (IL-1Ra) in bronchoalveolar lavage fluid (BALF) in patients with diffuse panbronchiolitis (DPB).

We evaluated the effect of erythromycin therapy on pulmonary function tests and the airway inflammatory response of patients with DPB. The number of neutrophils in BALF obtained from DPB patients was significantly higher than that of healthy volunteers. Treatment with erythromycin (600 mg/day for 12.9+/-9.5 months (mean +/- s.d.)) significantly reduced the total number of cells and neutrophils in the airway, and significantly improved pulmonary function tests. The levels of IL-1beta and IL-8 were significantly higher in DPB compared with healthy volunteers (P<0.05, P<0.05, respectively). IL-1Ra in patients is considered to have a weak inhibitory activity for IL-1beta, with approximately five-fold concentration of IL-1beta compared with that in healthy volunteers (approx. nine-fold concentration of IL-1beta). Erythromycin therapy significantly reduced these cytokines to levels comparable to those of healthy volunteers, and produced a trend toward reduction in the level of IL-1Ra in BALF. The level of IL-1beta correlated significantly with the concentration of neutrophils in BALF (r=0.72, P<0.01), as well as with the level of IL-1Ra (r=0.688, P<0.05) and IL-8 (r=0.653, P<0.05). A nearly significant or significant correlation was observed between the concentration of neutrophils and levels of IL-1Ra or IL-8 in BALF (r=0.526, P=0.053 or r=0.776, P<0.01, respectively). There was also a significant relationship between FEV(1) and the concentration of neutrophils in BALF (r=0.524, P<0.05). Our results suggest that the relative amounts of IL-1beta and IL-1Ra or IL-8 may contribute, at least in part, to the neutrophil-mediated chronic airway inflammation in patients with chronic airway disease, and long-term erythromycin therapy may down-regulate the vigorous cycle between the cytokine network and neutrophil accumulation, with resultant reduction of neutrophil-mediated inflammatory response.

Adult↗
PubMed1996

Mitotic and meiotic stability of the CAG repeat in the X-linked spinal and bulbar muscular atrophy gene.

X-linked spinal and bulbar muscular atrophy (SBMA) occurs due to an expansion of the trinucleotide repeat (CAG)n in the androgen receptor gene. Anticipation is relatively rare in SBMA in contrast to spinocerebellar ataxia type 1 (SCAl), and dentatorubral and pallidoluysian atrophy (DRPLA) which show obvious paternal anticipation. The differences in the CAG repeat number were compared among sperm, leukocytes and skeletal muscles of SBMA patients. In SBMA, the sperm of most patients and the skeletal muscle of all patients showed the same repeat number as their leukocytes, whereas the increase in the repeat number from leukocytes to sperm was evident in SCA1 and DRPLA patients. The higher mosaicism level in sperm compared with leukocytes was common in SBMA, SCA1 and DRPLA, and the level of sperm was lower in SBMA than in SCA1 and DRPLA. Thus, spermatogenesis was suggested to be strongly associated with paternal anticipation. The mosaicism level was smaller in SBMA than in other (CAG)n expanded disorders, and smallest in the SBMA carrier females. These findings demonstrate that the CAG repeat in SBMA is relatively stable in mitotic and meiotic, processes, and there is a possibility that the lower mosaicism level of the carrier females compared with the SBMA patients is associated with X-linked recessive inheritance.

Female↗
PubMed1996

Trisomy 13/trisomy 18 mosaicism in an infant.

Cytogenetic analysis of amniotic fluid cells from a 31-week-old fetus suffering from polyhydramnios revealed that there were two cell lines, each with either trisomy 13 or trisomy 18. We studied the origin and mechanism for formation of this unique mixoploidy by tracing chromosomal heteromorphisms as genetic markers, and showed no discordance of parent-child transmission between the two cell lines in any of the heteromorphisms examined. The result indicated that the mixoploidy is not chimerism but mosaicism and that the mechanism of mosaic development is most likely due to two non-disjunctional events which had occurred independently at the two-cell stage of the zygote. A girl was born at the 38th gestational week and her clinical features were mainly those for trisomy 13. Chromosome analysis of the newborn confirmed +13/+18 mosaicism in fibroblasts from the skin and chorionic plate, while cord blood lymphocytes and chorionic villus cells showed only the +18 cell line.

Abnormalities, Multiple↗
PubMed1996

Reduction of CAG expansions in cerebellar cortex and spinal cord of DRPLA.

Recent studies have identified an unstable expansion of a CAG repeat in a gene located on chromosome 12 as a cause of dentatorubropallidoluysian atrophy (DRPLA). To investigate whether the somatic heterogeneity may relate to the selective neuronal damage caused by the disease, genomic DNA from various tissues of an autopsied patient with DRPLA was examined to compare possible variations of expanded CAG repeats for the disease. Although the size of the expanded CAG repeat from many organs was almost the same as that from peripheral lymphocytes, those from cerebellar cortex and spinal cord were unexpectedly reduced and numbers of peaks within an expanded allele were relatively strict. These results suggest that the CAG repeat is not simply expanded in the genome of the tissues that are most involved in DRPLA, but that another mechanism might be responsible for the specific neuronal death.

Adult↗
PubMed1996

Increase in hepatic tissue blood flow by teprenone.

The major objective of the present study was to evaluate mechanisms by which teprenone, a gastric mucosal protecting agent, increases hepatic mucosal blood flow using male Sprague-Dawley rats. Hepatic and gastric blood flow was measured using a laser blood flow meter after administration of teprenone, dissolved in Tween 80, into the inferior vena cava. Teprenone itself increased hepatic and gastric blood flow. It also increased hepatic and gastric blood flow in rats with acute hepatic disorders due to carbon tetrachloride (CCL4) and improved histological changes, such as inflammatory cell infiltration and fatty changes in the liver. The fact that blood endothelin (ET) concentrations increased after administration of teprenone suggest that teprenone has great affinity for ET beta receptors and shows ET beta-receptor antagonist-like effects. Hepatic blood flow decreased after administration of N-nitro-L-arginine methyl ester, a nitric oxide (NO) synthetase inhibitor, suggesting that teprenone increase NO activity. Teprenone was thought to increase hepatic and gastric blood flow by different mechanisms, because it increased gastric mucosal prostaglandin E2 concentrations.

Animals↗
PubMed1996

Relationship between solvent inhalation and antisocial behavior: special emphasis on two types of violence seen in solvent abusers.

Organic solvent inhalation is a serious problem among youths in Japan. It induces physical and mental disorders, and is related closely to crime and delinquency. The relationship between solvent inhalation and antisocial behavior was investigated in 75 youths. The subjects were divided into three groups according to the level of violent behavior and the time of appearance: a non-violent group, a late-onset group (violence occurred after the start of inhalation) and an early-onset group (violence had occurred before the start of inhalation). Various parameters were compared among the groups. The late-onset group showed the following characteristics; (i) the frequency of inhalation was high, and many subjects experienced hallucinations and mood changes caused by inhalation; (ii) the family environment was characterized by conflict; and (iii) the subjects had strong psychological conflicts and showed dissociative coping with frustration. The violence, psychological conflict and dissociation in this group were found to be related to the inhalation, with familial conflict as a background. The violence in the early-onset group was considered to be the manifestation of a violent personality as the frequency of inhalation and the incidence of mental symptoms were both low. The subjects in this group showed weak psychological conflict and tended to be demanding of others when attempting to cope with frustration. Two types of violent behaviors in the teenagers who inhaled solvents were identified. The violence of solvent inhalers should be managed according to the type.

Administration, Inhalation↗
PubMed1996

The basomedial and basolateral amygdaloid nuclei contribute to the induction of long-term potentiation in the dentate gyrus in vivo.

Recent behavioural studies have provided evidence that the amygdala modulates hippocampal-dependent memory. To test the possibility that the amygdala modulates hippocampal synaptic plasticity, we investigated the effects of surgical lesions of the amygdaloid nuclei on the induction of long-term potentiation (LTP) in the dentate gyrus of anaesthetized rats. Previously we reported that LTP in the dentate gyrus was attenuated by lesion of the basolateral amygdala, but was not affected by lesion of the central amygdala. In the present study, dentate gyrus LTP was significantly attenuated by basomedial amygdala lesion but not by medial amygdala lesion. These results suggest that, among the amygdaloid nuclei, the basomedial and basolateral nuclei are involved in the modulation of hippocampal plasticity. The roles of the basomedial and basolateral amygdala were further supported by experiments examining the effects of electrical stimulation of these nuclei. High-frequency stimulation of the basomedial amygdala alone did not induce dentate gyrus LTP, but when applied at the same time as tetanic stimulation of the perforant path increased the magnitude of the dentate gyrus LTP. Similarly, high-frequency stimulation of the basolateral amygdala enhanced LTP induced by tetanic stimulation of the perforant path. Furthermore, facilitation of dentate gyrus LTP by basomedial or basolateral amygdala stimulation was observed even in rats lesioned in either amygdala, suggesting that neurons in the basomedial and basolateral amygdala can modulate dentate gyrus LTP independently. Activity-dependent facilitation of hippocampal plasticity by the basomedial and basolateral amygdala may underlie memory processing associated with emotion.

Amygdala↗
PubMed1996

Extracting 1/f fluctuation from the arterial blood pressure of an artificial heart.

We have studied the fluctuations of an artificial circulation for the analysis of the physiological aspects; however, the conventionally used fast Fourier transform (FFT) method cannot separate harmonic oscillations, such as respiratory and Mayer waves, from the 1/f fluctuation, which has been though to represent underlying fractal dynamics. Fractal structure was shown in the strange attractor with chaotic dynamics, which is thought to be a flexible and intelligent system. In this study, the coarse-graining spectral analyzing (CGSA) method was utilized to quantitatively evaluate the proportion of the 1/f fluctuation in the total power in the frequency domain and to analyze artificial circulation in the whole system. We implanted two pneumatically actuated ventricular assist devices as biventricular bypasses (BVBs) in chronic animal experiments using 4 healthy adult goats. To compare the natural and prosthetic circulation of each experimental animal, the BVB-type complete prosthetic circulation model with electrically induced ventricular fibrillation was adopted. All hemodynamic parameters of natural and prosthetic circulation were recorded under awake conditions and calculated with the use of a personal computer. With the use of the CGSA method, time-series data of the hemodynamics were analyzed and fractal percentages, extracting the 1/f fluctuation from a given time series, were calculated. Fractal percentages of the arterial blood pressure were 85.8 +/- 10.7% and 82.0 +/- 7.3% with natural and artificial circulation, respectively (not significant [NS]). 1/f fluctuation showed the characteristics of being fractal in a time series. The fractal structure showed robustness and error resistance in nonlinear dynamics. Therefore, our results suggest that the circulatory regulatory system of the artificial heart may have desirable characteristics such as error resistance.

Animals↗
PubMed1996

Irreversible sinus node dysfunction induced by resumption of lithium therapy.

We present the case of a 56-year-old woman with syncope and sinus node dysfunction after long-term lithium therapy. Following lithium discontinuation, sinus node function recovered completely. After resuming low doses of lithium, however, severe sinus node dysfunction recurred. Thereafter, sinus node function did not recover after lithium was discontinued, and a permanent pacemaker was implanted. These findings suggest that irreversible sinus node dysfunction should be recognized as a potentially fatal, albeit rare, risk of lithium therapy, and that previous recovery from sinus node dysfunction after long-term lithium treatment cannot always guarantee the reversible nature of this abnormality after resumption of lithium therapy.

Adult↗
PubMed1996

The effects of 5-hydroxydopamine on salivary flow rates and protein secretion by the submandibular and parotid glands of rats.

The secretory effects of 5-hydroxydopamine (5-OHDA) were tested in Nembutal-anaesthetized adult male Sprague-Dawley rats injected I.V. over a wide range of doses, with and without various autonomic antagonists and Ca2+ channel blockers. Polyacrylamide disc gel (15%) and iso-electric focusing (IEF) electrophoresis by the PhastSystem were used to separate and determine the types of protein in submandibular saliva. Amylase activity of parotid saliva was determined by the blue dextran method. Salivation by the submandibular glands following application of 5-OHDA was completely abolished by both prazosin and propranolol, whereas salivation by the parotid glands was completely abolished by propranolol alone. Following application of 5-OHDA, there was a dose-related increase in flow rates and total output of protein, but not in the protein concentration and amylase activity, from both salivary glands. The effect of 5-OHDA on submandibular saliva was significantly reduced by alpha-adrenoceptor blockers, but not by beta-adrenoceptor and cholinergic blockers, nor by any Ca2+ channel blocker. The effect of 5-OHDA on the parotid gland was not significantly altered by atropine and phentolamine. However, after pretreatment with reserpine, a 95% reduction was observed in the salivation from the submandibular gland. This implies that 5-OHDA is mostly acting indirectly via release of noradrenaline. The proteins in submandibular saliva following treatment with 5-OHDA alone or 5-OHDA in combination with beta-adrenoceptor blockers were mainly of the alpha-type, whereas after treatment with 5-OHDA in combination with alpha-adrenoceptor blockers they were of the beta-type. The alpha-type was found in saliva after treatment with each of three Ca2+ channel blockers.

Adrenergic alpha-Antagonists↗