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Biomedical subjects

K Aoki

Publications and source records attributed to K Aoki.

At least 37 records · Page 2Linked to original sources
PubMed1998

[Obesity as one of the risk factors for urolithiasis].

BACKGROUND: It is well known that many diseases may be associated with obesity resulting from an energy-rich diet, and that a westernized diet may increase the incidence of urinary stone formation. To evaluate degree of obesity, we investigated body mass index (BMI) in patients with calcium containing upper urinary stones and examined their blood with regard to lipid metabolism. METHODS: Between July 1994 and December 1995, we analyzed 332 fresh renal-stone formers (253 males and 79 females) who visited 7 hospitals located in Ehime prefecture. As a control, 949 residents older than 20 years (387 males and 562 females) of the same prefecture were also examined by the annual Ehime prefecture office report of 1994. Body mass index as degree of obesity, stone-recurrence, blood test and other complicated diseases were examined. RESULTS: In male stone formers the rate of obesity was significantly higher than that of control males (p < 0.001). The differences were seen only in their twenties and fifties. Furthermore, among male stone formers the rate of obesity was significantly higher in recurrent stone formers than in single stone formers (p < 0.05). On the other hand, in female, there was no significant difference in the rate of obesity between stone formers and controls. No difference was seen between recurrent stone formers and single stone formers. In the blood test, there was no differences in the level of calcium, phosphate and uric acid between stone formers and controls. The level of cholesterol and triglyceride in male were significantly higher in controls (p < 0.01) and there was no difference in the level of high density lipoprotein (HDL) between stone formers and controls. Among the stone formers, 48 males (20.0%) and 17 females (21.5%) had other diseases. The rate of complicated diseases was similar to that of controls and no specific diseases in the stone formers were identified. CONCLUSION: Our report suggested that obesity in male should be considered as a risk factor for calcium containing stone formation.

Adult↗
PubMed1998

[Treatment of patients with recurrent esophageal carcinoma].

From 1987 to 1997, 211 patients with thoracic esophageal carcinoma underwent radical surgery. The 5 year survival rate was 87% in pTNM stage I, 64% in stage II A, 57% in stage II B, and 31% in stage III. The survival curve was improved by postoperative chemotherapy including CDDP/5-FU as compared with surgery alone. Relapse occurred in 59 of these patients (28%). Lymphatic recurrence was recognized in 32 patients, hematogenic recurrence in 19, mixed type in 4, and intramural or local recurrence in 4 patients. In spite of through lymph node dissection, postoperative lymphatic recurrence was most frequent at the upper mediastinum and neck. Among hematogenic metastases, pulmonary and hepatic metastases were observed at equal incidences. The 1 year survival rate and median survival period of the patients with recurrent carcinoma were 36% and 191 days (26-1,122), respectively. There was no significant difference in prognosis between lymphatic and hematogenic recurrence. The prognosis for patients who underwent active therapy for recurrence (42 cases) was significantly better than for those who underwent only palliative therapy (17 cases). Resection of the site of recurrence was performed in 4 cases. The combination therapy of resection or irradiation and combined chemotherapy with CDDP and 5-FU resulted in a better prognosis (median survival period was 504 days) than irradiation alone or chemotherapy alone. In conclusion, early diagnosis and active multimodality therapy were important to improve the prognosis of recurrent esophageal carcinoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

[Prevertebral abscesses with a protracted insidious clinical course and subsequent lethal, acute pyogenic meningitis and septic shock].

This report concerns a 66-year-old man suffering from prevertebral abscesses with a protracted insidious clinical course and subsequent lethal and acute pyogenic meningitis. The patient had a three-month history of mild neck pain, and died as a result of septic shock due to staphylococcus aureus (methicillin susceptible) infection two days after admission to the hospital. At autopsy, abscesses encapsulated by fibrous connective tissue were found on the ventral surfaces of the cervical and thoracic regions of the spine. The prevertebral abscess on the upper cervical region was organized with dense fibrous tissue and contained a small number of inflammatory cells. On the other hand, the prevertebral abscess on the thoracic region was purulent and contained numerous inflammatory cells, macrophages and gram-positive cocci. Pyogenic spondylitis and discitis accompanying the prevertebral abscesses were multiple and widespread. These features suggested that the abscesses developed initially on the cervical region, extended caudally through the prevertebral space, directly involving the corpus vertebrae and discs, and ultimately caused sepsis. It is important to note that prevertebral abscesses can exhibit a protracted clinical course with only mild symptom such as minor neck pain and then manifest abruptly as acute meningitis and sepsis.

Abscess↗
PubMed1998

Mutations in the human homologue of the Drosophila patched gene in esophageal squamous cell carcinoma.

The human homologue (PTCH) of the Drosophila segment polarity gene patched has recently been identified as a tumor-suppressor gene for nevoid basal cell carcinoma syndrome and for sporadic basal cell carcinomas of the skin. We analyzed 30 esophageal squamous cell carcinomas (ESCC) for intrageneic mutations of the PTCH gene by polymerase chain reaction-single-strand conformation polymorphism analysis followed by DNA sequencing. We identified two somatic PTCH mutations (7%) in 30 ESCC. These were a nonsense mutation (CAG to TAG at codon 361) in exon 8 and a missense mutation (CAG to CTG, Gln to Leu at codon 816) in exon 14. These tumors exhibited loss of heterozygosity at the polymorphic site of the PTCH gene. These results indicate that inactivation of the PTCH gene via a two-hit mechanism occurs in a subset of ESCC.

Amino Acid Substitution↗
PubMed1998

[Functional difference between the left supplementary motor area and the left premotor area in a task of confrontation naming and word fluency].

We assessed the faculty of confrontation naming and word fluency of the 11 patients afflicted with frontal lobe infarction or hemorrhage. All the patients were right-handed and manifested transcortical motor aphasia due to cerebrovascular diseases. We carried out the Western Aphasia Battery, and we adopted V-A; the naming task involved confrontation naming of 20 objects, and V-B; the word fluency task involved the naming as many animals as possible in a one minute period. Six patients who have lesions in the left medial frontal lobe performed excellency in the confrontation naming task but exhibited poor word fluency, and 5 patients who have lesions in the left dorso-lateral frontal lobe performed poorly in both tasks. This results suggests that the left dorso-lateral frontal lobe is important in confrontation naming, while the left medial frontal lobe is important in word fluency. Mushiake et al. (1991) showed that the premotor area was involved in visually guided sequential movements, and the supplementary motor area was involved internally determined sequential movements in primates. Regarding language function as analogous to movement, confrontation naming is analogous to visually guided movements and word fluency is analogous to internally determined movements. Thus, our results suggest that the functional difference between the left medial frontal lobe, which includes the supplementary motor area, and the left dorso-lateral frontal lobe, which includes the premotor area, which was demonstrated in primates for movement is also true of language function in humans.

Aphasia, Broca↗
PubMed1998

[A management for severe acquired stuttering in a case of pure akinesia syndrome].

We reported a 73-year-old man with pure akinesia syndrome who showed severe acquired stuttering and paradoxical kinesia on speech. He was evaluated in another hospital for bradykinesia and frozen gait at age of 67 when his cranial MRI disclosed ischemic changes in bilateral basal ganglia and periventricular deep white matter. The treatment with L-dopa and L-threo DOPS was not effective. His symptoms were slowly progressive and got worse gradually. At age of 72, he began to have difficulty in speech due to severe acquired stuttering, and one year later, he visited our hospital. The diagnosis of pure akinesia syndrome was made because of akinesia, micrographia, marked frozen gait with paradoxical kinesia and disturbance of postural reflex without tremor and rigidity. His speech showed severe acquired stuttering with marked blocking and repetition of initial phonemes at the beginning of speech. But intelligible speech recurred with pointing the characters by his finger or with writing an initial letter of word, although his speech was small and monotonous. Surface EMG findings of muscles participating speech in acquired stuttering showed the similar tonic discharge to those of muscles of lower extremity in frozen gait. These results implied that freezing phenomenon and festination of muscles participating speech in our patient may result in acquired stuttering.

Aged↗
PubMed1998

Evaluation of thrombopoiesis in thrombocytopenic disorders by simultaneous measurement of reticulated platelets of whole blood and serum thrombopoietin concentrations.

To evaluate thrombopoiesis in thrombocytopenic disorders, we simultaneously determined reticulated platelet counts in whole blood by FACScan flow cytometry and serum thrombopoietin (TPO) concentrations by a sensitive sandwich ELISA. The subjects were 40 healthy volunteers and 45 thrombocytopenic patients. In idiopathic thrombocytopenic purpura (ITP), the percentage of reticulated platelets was significantly elevated (5.61 +/- 2.02%: mean +/- SD) relative to normal controls (2.17 +/- 0.90%), but serum TPO concentrations (1.91 +/- 1.27 fmol/l) did not differ significantly from the normal range (1.43 +/- 0.62 fmol/l). The patients with aplastic anemia (AA) had decreased reticulated platelet counts and markedly increased serum TPO concentrations (13.65 +/- 10.64 fmol/l). In thrombocytopenic patients with liver cirrhosis (LC), the absolute number of reticulated platelets (1.65 +/- 1.11 x 10(9)/l) decreased similarly that in AA. However, serum TPO concentrations (1.38 +/- 0.50 fmol/l) did not increase in contrast to AA. Our findings suggested a possible dual mechanism of thrombocytopenia in LC; that is, thrombocytopenia in LC results from the decreased TPO production primarily in the liver adding to an increase in platelet sequestration in the spleen.

Anemia, Aplastic↗
PubMed1998

Mitral valve aneurysm as a sequela of infective endocarditis: review of pathologic findings in Japanese cases.

Mitral valve aneurysm is defined as a localized protrusion of the valve with a different radius from that of the remaining portion of the valve. The medical records and pathological findings of seven patients with mitral valve aneurysm [aged 48-69 years (mean 64), 4 males] and the pathological findings of other 29 Japanese cases were reviewed. All seven patients were diagnosed pathologically as infective endocarditis, but two patients had no documentation of clinical symptoms suggestive of infective endocarditis (latent infective endocarditis). The underlying lesion of the heart was aortic valve disease and/or fibrosal degeneration of the mitral valve. Only 29 of 36 Japanese case reports stated a precise description of the valve pathology. Of these 29 cases, 23 were associated with infective endocarditis, two with rheumatic valvular disease with fusion and/or shrinkage of the chordae tendineae, three with mitral valve prolapse or myxomatous degeneration of the mitral valve, and one with aortitis syndrome. Neovascularization was described in eight cases. Neovascularization with thick wall should be considered as post-inflammatory vascularization. This review indicates that patients with latent infective endocarditis and mitral valve aneurysm should be considered as potential candidates for valve surgery.

Aged↗
PubMed1997

Circadian variation in skin blood flow responses to passive heat stress.

To examine whether there is a circadian variation in skin blood flow response to passive heat stress and maximal skin blood flow, which was measured by local warming to 42 degrees C for 45 min, we studied six men at an ambient temperature of 28 degrees C at four different times of day [0400-0700 (morning), 1000-1300 (daytime), 1600-1900 (evening), and 2200-0100 hours (night)], each time of day being examined on separate days. Heat stress at rest was performed by immersing the legs below the knee in hot water (42 degrees C) for 60 min. The esophageal temperature (Tes) at rest was significantly higher in the evening than in the morning. The maximal skin blood flow (SkBFmax) on both sites, back and forearm, did not show a significant difference among the four times of day. The variation in Tes thresholds for cutaneous vasodilation to heat stress was similar to the circadian rhythm in resting Tes. The relationship of the percentage of SkBFmax (%SkBF) with Tes was significantly lower in the morning than in the evening. The results suggest that the maximal skin blood flow during local warming does not show variation over the day, but the sensitivity of vasodilation to passive heat stress shows a circadian variation.

Adult↗
PubMed1997

Calorimetric observation of a GroEL-protein binding reaction with little contribution of hydrophobic interaction.

Binding of Escherichia coli chaperonin, GroEL, to substrate proteins with non-native structure, reduced alpha-lactalbumin (rLA) and denatured pepsin, were analyzed by isothermal titration calorimetry at various temperatures in the presence of salt (0.2 M KCl). Both proteins bound to GroEL with 1:1 stoichiometry and micromolar affinity at all temperatures tested. However, thermodynamic properties of their binding to GroEL are remarkably different from each other. While heat capacity changes (DeltaCp) of rLA-GroEL binding showed large negative values, -4.19 kJ mol-1 K-1, that of denatured pepsin-GroEL binding was only -0.2 kJ mol-1 K-1. These values strongly indicate that the hydrophobic interaction is a major force of rLA-GroEL binding but not so for denatured pepsin-GroEL binding. When salt was omitted from the solution, the affinity and DeltaCp of the rLA-GroEL binding reaction were not significantly changed whereas denatured pepsin lost affinity to GroEL. Thus, in the non-native protein-GroEL binding reaction, thermodynamic properties, as well as the effect of salt, differ from protein to protein and hydrophobic interaction may not always be a major driving force.

Calorimetry↗
PubMed1997

A gene-culture coevolutionary model for brother-sister mating.

We present a gene-culture coevolutionary model for brother-sister mating in the human. It is shown that cultural--as opposed to innate--determination of mate preference may evolve, provided the inbreeding depression is sufficiently high. At this coevolutionary equilibrium, sib mating is avoided because of cultural pressures.

Biological Evolution↗
PubMed1997

Growth regulation of human prostate cancer cells by bone morphogenetic protein-2.

Bone morphogenetic proteins (BMPs) belong to the transforming growth factor-beta (TGF-beta) family and have been identified as factors that stimulate bone formation in vivo. They turned out to be multifunctional molecules regulating the growth, differentiation, and apoptosis in various target cells. Some BMPs and their receptors (BMPRs) are expressed on prostate cancer cells. We have reported previously that BMPR-IB mRNA expression is highest in the prostate, a characteristic that is not shared by the other BMPRs, BMPR-IA and BMPR-II. However, the amounts of BMPR-IB mRNA were significantly low in prostate tissues after androgen withdrawal therapy. They were also low in prostate cancer cell lines. Semiquantitative RT-PCR showed that BMPR-IB mRNA was induced by androgen in the androgen-sensitive human prostatic cancer cell line LNCaP, whereas the expression of BMPR-IA and BMPR-II mRNAs was not affected by androgen. When the recombinant human BMP-2 was added to the LNCaP cells in the presence of androgen, cell growth was inhibited. In contrast, the growth rate was increased by the addition of the same ligand when the cells were cultured in the absence of androgen; under this condition, the amounts of BMPR-IB mRNA were decreased significantly. These observations showed that the amounts of BMPR-IB, but not those of BMPR-IA, were regulated by androgen and further suggest that BMPR-IA and BMPR-IB differentially modulate prostate cancer cell growth in response to BMP under different hormonal conditions; BMPR-IA elicits growth stimulation, and BMPR-IB conveys a negative regulatory signal in response to BMP-2.

Bone Morphogenetic Protein 2↗
PubMed1997

Cocaine-induced liver injury in mice is mediated by nitric oxide and reactive oxygen species.

The modulating effects of nitric oxide (NO) and reactive oxygen species on cocaine-induced hepatotoxicity were examined by measuring plasma alanine aminotransferase activity and by carrying out histological studies. Liver injury was induced by a single injection of cocaine in adult male ICR mice. Pretreatment with aminoguanidine (an inhibitor of NO synthase), N-methyl-D-glucamine dithiocarbamate complex with iron ion (II) (Fe2+(MGD)2, a trapping reagent of NO) or deferoxamine complex with iron ion (III) (Fe3+-deferoxamine, a scavenger of NO) produced a marked inhibition of the hepatotoxicity induced by cocaine. In addition, pretreatment with allopurinol (an inhibitor of xanthine oxidase) and 1,3-dimethylthiourea (a scavenger of hydroxyl radical) also produced a potent inhibition. These findings suggest that a hydroxyl radical produced by the reaction of NO and superoxide anion (O2-) via peroxynitrite may be involved in the pathogenesis of cocaine hepatotoxicity.

Allopurinol↗
PubMed1997

Specific and amplified current responses to histidine and histamine using immobilized copper-monoamine oxidase membrane electrode, based on novel ascorbate oxidase activity induced by exogenous ligands.

Upon the addition of histidine and histamine, the copper containing monoamine oxidase (MAO) catalyzes the oxidation of L-ascorbic acid (AsA) by dissolved oxygen, in which the consumed oxygen was finally converted to hydrogen peroxide, according to Michaelis-Menten kinetics (Km) = 1.97 mM, upon the addition of 5 x 10(-5) M L-histidine at 35 degrees C and pH 8.5). The amount of oxygen consumption depended on the amount of histidine and histamine added, and specific responses over other amines were observed when the oxygen electrode modified with immobilized MAO membrane was used in the 0.1 M Tris buffer containing AsA. The calibration curves of L-histidine and histamine at 4 mM AsA exhibit linearity in the concentration range from 5 x 10(-7) to 5 x 10(-5) M L-histidine and 5 x 10(-6) to 1 x 10(-8) M histamine, with detection limit of 3 x 10(-7) M L-histidine and 3 x 10(-6) M histamine, respectively. The ESR signal of copper(II) in active site of MAO at 77K was apparently changed upon the addition of L-histidine and histamine indicating that exogenous histidine and histamine bound to the copper site of enzyme and lead to the structural change in active site.

Animals↗