Biomedical subjects

A Hara

Publications and source records attributed to A Hara.

At least 361 records · Page 20Linked to original sources

PubMed1992

Purification and characterization of pig lung carbonyl reductase.

A pyrazole-sensitive carbonyl reductase from pig lung was purified to homogeneity by electrophoretic criteria. Chemical cross-linking study suggested that the native enzyme is a tetramer with a Mr of 103,000, consisting of apparent identical subunits of Mr 24,000. The enzyme reduced aliphatic and aromatic carbonyl compounds with NADPH as a preferable cofactor to NADH and catalyzed the oxidation of secondary alcohols and the aldehyde dismutation in the presence of NAD(P)+. Immunohistochemical study with the antibodies against the enzyme revealed that the enzyme was localized in the ciliated cells, nonciliated bronchiolar cells, Type II alveolar pneumocytes, and the epithelial cells of the ducts of the bronchial glands in the pig lung. In addition to the properties and distribution, the pig lung enzyme was immunochemically similar to the pulmonary enzymes in the guinea pig and mouse. However, the pig enzyme showed the following unusual features. (1) The enzyme exhibited an equatorial specificity in the reduction of 3-ketosteroids; the 4-pro-S hydrogen of NADPH was transferred to the carbonyl carbon atom of 5 alpha- and 5 beta-androstanes, and the respective reduced products were identified as 3 beta- and 3 alpha-hydroxysteroids. (2) Although the NADPH-linked reduction of carbonyl compounds apparently obeyed the Michaelis-Menten kinetics at pH 6.0, the double-reciprocal plots of the velocity vs concentrations of the carbonyl substrates were convex at pH higher than 6.5. The Hill coefficients and [S]0.5 values for the substrates decreased as the pH for reaction increased. The results suggest that the pig enzyme exhibits negative cooperativity with respect to the carbonyl substrates and that the hydrogen ion acts as an allosteric effector abolishing the negative interaction.

Alcohol Dehydrogenase↗

PubMed1992

Activation of carbonyl reductase from pig lung by fatty acids.

The NADPH-linked reductase activity of pig lung carbonyl reductase was activated two- to fivefold by fatty acids with a carbon chain length greater than nine at pH 7.0. cis-Unsaturated fatty acids of C:18 and C:20 were potent activators, showing Ka values of 2-14 microM which were lower than the values of 21-125 microM for saturated fatty acids (C:9 to C:16). Of the fatty acids arachidonic acid (C20:4) gave the highest activation. No significant stimulatory effect was observed with acyl CoAs, fatty alcohols, phospholipids, and nonionic detergents. Anionic detergents (sodium dodecyl sulfate and sarkosyl) stimulated the enzyme activity more than ninefold, but the Ka values for them were much higher than those for the cis-unsaturated fatty acids. Although no change in molecular weight or in subunit composition was observed in the enzyme activated by C20:4, the activation led to a decrease in thermal stability of the enzyme. The binding of C20:4 to the enzyme was instantaneous and reversible, shifted the pH optimum of the activity from 5.8 to 6.5, and changed the inhibitor sensitivity. In addition, C20:4 acted as an allosteric effector abolishing the negative interaction of the enzyme with carbonyl substrates which was seen without the fatty acid, but the activation increased both Vmax and [S]0.5 values for the substrates. Kinetic analysis with respect to NADPH concentration, in which no cooperativity was detected with or without C20:4, indicated that C20:4 was a nonessential activator of mixed type showing a binding constant of 10 microM. These results suggest that cis-unsaturated fatty acids may be potential modulators of pulmonary carbonyl reductase.

Alcohol Oxidoreductases↗

PubMed1992

Proliferative assessment of craniopharyngioma and epidermoid by nucleolar organizer region staining.

The histologic distinction between craniopharyngioma and epidermoid is equivocal. Eight craniopharyngiomas and ten epidermoids (including three dermoids) as well as nine rat (Wistar) abdominal skins that acted as control were investigated by a silver colloid method for nucleolar organizer regions (Ag-NORs). The mean number of Ag-NORs in at least 200 cells of both basal (columnar) epithelial cells and suprabasal (prickle) cells was evaluated. It was found that the mean number of Ag-NORs in basal cells of epidermoid and rat skin was significantly greater than that in suprabasal cells (P < 0.001 in nine of ten epidermoids and in all rat skins). On the other hand, of eight craniopharyngiomas, the mean Ag-NOR number in basal cells was not significantly different from that in suprabasal cells in five cases, and, further, the former was significantly smaller than the latter in the other three cases (P < 0.01 in two and P < 0.05 in one). These findings suggest that a stepwise maturation of the epithelial cells like that in mammalian skin epidermis exists in epidermoids but not in craniopharyngiomas. In craniopharyngiomas, the maturation of the epithelial cells seems to be considerably limited or lost from the aspect of proliferative potential as assessed by Ag-NOR score, which indicates neoplastic growth of craniopharyngiomas. Ag-NOR staining may thus be a useful method to distinguish craniopharyngioma from epidermoid.

Animals↗

PubMed1992

Distribution of cellular carbohydrate moieties in human dysontogenetic brain tumors, especially in craniopharyngioma and epidermoid/dermoid.

Cellular carbohydrate moieties of 65 human dysonotogenetic brain tumors (craniopharyngioma, epidermoid/dermoid, Rathke cleft cyst, germinoma and non-germinomatous germ-cell tumors) and 60 common brain tumors (glioma, meningioma, neurinoma and pituitary adenoma) were investigated histochemically using sections from Ulex europaeus (UEA-1), Dolichos biflorus (DBA), peanut (PNA) and soybean (SBA), and with anti-blood group A and LewisY (LeyY) antibodies. In craniopharyngiomas and epidermoid/dermoids, it was found that PNA and SBA binding sites existed in suprabasal cells of the epithelium, and that antigen of either blood group A or H (demonstrable by UEA-1) existed in more differentiated epithelial cells compared to the results reported in normal human skin epidermis. Rathke cleft cysts were stained with PNA or SBA, and two out of three Rathke cleft cysts also expressed either H or A antigen. In addition, DBA binding sites, as well as LeY antigen, were frequently seen in craniopharyngiomas and Rathke cleft cysts, but they were entirely absent in the epithelium of epidermoid/dermoid. On the other hand, PNA and SBA reactivities was also found in common brain tumors, while blood group A, H and LeY antigens and DBA reactivity were almost absent in these tumors. These findings demonstrate that carbohydrate moieties such as those of blood group antigens reported to be found in human skin epidermis exist in a similar form in craniopharyngioma, epidermoid/dermoid and the Rathke cleft cyst. The identification of blood group A, H and LeY antigens and DBA reactivity in brain tumors seems to be considerably limited and specific.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, Neoplasm↗

PubMed1992

Dolichos biflorus agglutinin binding to intracranial germ-cell tumors: detection of embryonal components in germinomas.

Dolichos biflorus agglutinin (DBA) binding was examined in 32 cases of intracranial human germ-cell tumors. In embryonal carcinomas, intense DBA binding sites were found on the free surface and cytoplasm of embryonal cells. In teratomas, glandular structures often had positive DBA binding sites. Yolk sac carcinomas and choriocarcinomas showed negative DBA affinity. Of 19 cases of germinomas, 10 showed no DBA-positive cells, while sporadically and/or collectively distributed-DBA positive cells were found in the other 9 cases. Common brain tumors such as gliomas, neurinomas and meningiomas were negative for DBA staining. Considering the cellular carbohydrate structure, these findings suggest that DBA-positive cells in germinoma might be evidence of differentiation into embryonal or some somatic components. In addition, because of the absence of DBA binding sites in the common brain tumors, the identification of such binding sites in brain tumors might act as a marker for embryonal or somatic components, especially among germ-cell tumors.

Alkaline Phosphatase↗

PubMed1992

CD45 isoform expression on human neonatal T cells: expression and turnover of CD45 isoforms on neonatal versus adult T cells after activation.

Neonatal T cells are phenotypically similar to "naive" T cells from adult donors in the CD45 isoform expression. Despite the phenotypic similarity, large differences were found between neonatal and adult T cells when T cells were activated. After activation with PHA, adult CD45RA+ T cells began to express CD45RO and no loss of CD45RA expression had yet occurred at Day 3 post-stimulation. Three days after activation, CD45RA+ neonatal T cells also coexpressed CD45RO; however, in contrast to adult T cells, a marked loss of CD45RA was observed. We analyzed the rapid loss of CD45RA found in neonatal T cells. The de novo synthesis of CD45 isoforms in neonatal T cells was essentially the same as that in the adult T cells. Turnover of the CD45RA was very rapid in both resting adult and neonatal T cells. After activation with PHA, the turnover of CD45RA on adult T cells was decreased significantly, while the turnover of CD45RA on neonatal T cells was not changed after activation. Therefore, the regulation of CD45 isoform expression not only involves switches in alternative splicing, but also involves different regulation of turnover of these isoforms from the cell membrane.

Adult↗

PubMed1992

Metallic elements in the perilymph measured with an inductively-coupled plasma atomic emission spectrometer.

Metallic elements in the perilymph of the scala tympani in normal and acoustically overstimulated guinea pigs were measured using a new method, an inductively-coupled plasma atomic emission spectrometry. The concentrations of phosphorus and eight metallic elements, i.e. calcium, copper, iron, potassium, magnesium, sodium, lead and zinc were measured simultaneously in a 2 microliters sample of perilymph. The mean concentration values of calcium, copper, iron, magnesium, phosphorus, lead and zinc were 2.03 mM, 38.5 microM, 69.3 microM, 0.822 mM, 0.851 mM, 43.5 microM and 25.0 microM, respectively. There was no significant effect of acoustic overstimulation on the concentrations of these elements except for magnesium, which decreased significantly after the exposure to a intense sound (2 kHz, 115 dB SPL) for 15 min. This is the first report describing the synchronous determination of metallic poly-elements, including copper, iron, lead and zinc, in the perilymph.

Acoustic Stimulation↗

PubMed1992

Acute toxicity of ozone against morphology of gill and erythrocytes of Japanese charr (Salvelinus leucomaenis).

1. Acute toxicity of ozone exposure to Japanese charr (Salvelinus leucomaenis) was studied histopathologically, and hematologically on gill tissue and red blood cells (RBC) under different ozone concentrations (0-0.7 ppm). 2. Exposure of ozone above 0.7 ppm led to characteristic symptoms and all died of choking in 30 min. 3. Many swollen RBC were seen under the scanning electron microscope. 4. RBC congestion was serious in the gill where degeneration of lamellar epithelium was observed. However, injury to chloride cells was not clear.

Animals↗

PubMed1992

Extra-adrenal pheochromocytoma-ganglioneuroma. A case report.

A case of rare extra-adrenal tumor composed of pheochromocytoma-ganglioneuroma which developed in a 48-year-old Japanese male is reported. Histologically, the tumor contained equal proportion of two distinct patterns, pheochromocytoma and ganglioneuroma. Immunohistochemical examination revealed that pheochromocytoma cells were positive for Leu-7 and ganglion cells in ganglioneuroma were positive for vasoactive intestinal peptide (VIP), respectively. Neuron specific enolase (NSE) was positive in the neoplastic cells of both components, and S-100 protein was also positive in fibers around ganglion cells. Ultrastructural examination revealed that neurosecretory granules were present in the neoplastic cells.

Ganglioneuroma↗

PubMed1992

The hearing of the patients treated with hemodialysis: a long term follow-up study.

Sensorineural hearing loss is frequently found in the patients under the treatment with hemodialysis, but the responsible etiological factor(s) still remains controversial. The purpose of the present study was to determine by a long term follow-up study whether hemodialysis per se or other factors induce sensorineural hearing loss. Thirty-seven patients with the observation periods of 4 years or longer were selected for the analysis. Hearing tests were performed soon after the initiation of hemodialysis and every 3 to 12 months thereafter. Significant hearing loss was found in 16 cases (31 ears) at the first test. Although 3 cases (5 ears) of the initially normal group and one case (2 ears) of the group with already existing hearing loss exhibited significant hearing loss, the change in the hearing level was quite minimal in remaining 67 ears during the observation period. Although the cochlea in patients under the treatment with hemodialysis is susceptible to various insults, we conclude that hemodialysis per se does no harm to the cochlea and the hearing can be maintained at the pre-hemodialysis level in the majority of the cases.

Adult↗

PubMed1992

Modification of pig liver dimeric dihydrodiol dehydrogenase with diethylpyrocarbonate and by rose bengal-sensitized photooxidation: evidence for an active-site histidine residue.

Dihydrodiol dehydrogenase from pig liver was inactivated by diethylpyrocarbonate (DEP) and by rose bengal-sensitized photooxidation. The DEP inactivation was reversed by hydroxylamine and the absorption spectrum of the inactivated enzyme indicated that both histidine and tyrosine residues were carbethoxylated. The rates of inactivation by DEP and by photooxidation were dependent on pH, showing the involvement of a group with a pKa of 6.4. The kinetics of inactivation and spectrophotometric quantification of the modified residues suggested that complete inactivation was caused by modification of one histidine residue per active site. The inactivation by the two modifications was partially prevented by either NADP(H) or the combination of NADP+ and substrate, and completely prevented in the presence of both NADP+ and a competitive inhibitor which binds to the enzyme-NADP+ binary complex. The DEP-modified enzyme caused the same blue shift and enhancement of NADPH fluorescence as did the native enzyme, suggesting that the modified histidine is not in the coenzyme-binding site of the enzyme. The results suggest the presence of essential histidine residues in the catalytic region of the active site of pig liver dihydrodiol dehydrogenase.

Alcohol Oxidoreductases↗

PubMed1992

Inhibition of dimeric dihydrodiol dehydrogenase by 4-hydroxyphenylketone derivatives: aspects of inhibitor structure and binding specificity.

Dimeric dihydrodiol dehydrogenases from pig liver, monkey kidney, and rabbit lens were inhibited more potently by 4-hydroxyphenylketones such as 4-hydroxybenzaldehyde, 4-hydroxyphenylglyoxal, and 4-hydroxyacetophenone than by isoascorbate and ascorbate, known inhibitors of the enzymes. No significant inhibition was observed with 2- or 3-hydroxyphenylketones, phenylketones with a functional group other than a hydroxy group at the 4-position, and 4-hydroxyphenyl derivatives without a carbonyl group. The steady-state kinetic analyses of the inhibition of the pig liver enzyme indicated that the 4-hydroxyphenylketones, similarly to ascorbate and its epimer, bound to an enzyme-NADP+ binary complex as competitive inhibitors with respect to dihydrodiol substrate. The inhibition by the 4-hydroxyphenylketones was uncompetitive with respect to isoascorbate, and the addition of one of the 4-hydroxyphenylketones or isoascorbate with NADP+ afforded a great protective effect against inactivation of the enzyme by diethylpyrocarbonate or by heat treatment, which indicates that 4-hydroxyphenylketones and isoascorbate bind at the same site in or near the active center of the enzyme. The structural comparison of 4-hydroxybenzaldehyde and ascorbate suggests that the hydroxy group at C-5, carbonyl group at C-1 and lactone ring of ascorbate are important for the binding to the enzyme.

Alcohol Oxidoreductases↗

PubMed1992

Extended latissimus dorsi musculocutaneous flaps for extremely wide cervical skin defects involving the cervical esophagus.

Two cases using island distally and anteriorly extended latissimus dorsi musculocutaneous flaps for one-stage reconstruction of pharyngoesophageal defects of the entire front of the neck are reported. The advantage of this flap is its extremely large skin territory, which provides a reliable vascular supply. This flap is suitable for extremely wide cervical defects where the recipient vessels are damaged after severe infection and irradiation.

Aged↗

PubMed1992

Coronary artery vasoreactivity to intracoronary acetylcholine infusion test in patients with chest pain syndrome.

Coronary vasoreactivity of patients with chest pain syndrome (CPS, 18 patients) was examined with intracoronary acetylcholine infusion test (ACh). For comparison, 10 patients with vasospastic angina (VSA) and 17 patients without chest pain (control group) were used. The luminal diameters of coronary arteries were measured before and after ACh, and the maximal value of constriction rate of each segment (MCR) was used as index of vasoreactivity in each patient. By the ACh test, an average MCR of 42 +/- 23% was observed in CPS, 84 +/- 17% in VSA, and 26 +/- 12% in the control group. In CPS, chest pain was induced by ACh in 7 patients (group I), but was not induced in the other 11 patients (group II). The average MCR of group I (66 +/- 18%) was significantly higher than group II (28 +/- 9%, p less than 0.01) and the control group (p less than 0.01), though lower than VSA (p less than 0.05). These findings suggest that increased coronary vasoreactivity may play an important role in the chest pain development in CPS.

Acetylcholine↗

PubMed1992

Lectin cytochemistry combined with silver colloid staining of argyrophilic nucleolar organizer regions in human gliomas.

Investigation of lectin cytochemical staining of inflammatory cells in human gliomas showed that Allomyrina dichotoma (Allo-A) cytochemistry can reliably distinguish inflammatory from neoplastic cells. Allo-A cytochemistry combined with silver colloid staining of argyrophilic nucleolar organizer regions (Ag-NORs) was performed in human gliomas. Inflammatory cells possessed usually one but sometimes two Ag-NORs and macrophages often possessed several Ag-NORs. The mean Ag-NOR number per nucleus of inflammatory cells ranged from 1.81 to 2.34, and that of neoplastic cells ranged from 2.57 to 3.53 and from 2.84 to 4.46 in low- and high-grade gliomas, respectively. The mean Ag-NOR number per nucleus of inflammatory cells was significantly smaller than that of neoplastic cells (p less than 0.001). Combined Allo-A cytochemical and silver colloid Ag-NOR staining can provide a reliable Ag-NOR number in human gliomas by distinguishing inflammatory cells.

Brain Neoplasms↗

PubMed1992

Effect of ozone on the activities of reactive oxygen scavenging enzymes in RBC of ozone exposed Japanese charr (Salvelinus leucomaenis).

The effect of ozone exposure on the activities of reactive oxygen scavenging enzymes (SOD, catalase, GSH-Px) in RBC of Japanese charr (Salvelinus leucomaenis) was examined. Ozone (0, 0.4 and 0.7 ppm as initial concentrations) was exposed to Japanese charr for 30 min, which definitely caused serious membrane damage to RBC of fish. Ozone exposure at 0.4 and 0.7 ppm decreased activities of both catalase and GSH-Px by 80 to 57% of the control. On the other hand, the activities of SOD remained unaffected even by 0.7 ppm ozone exposure. A hypothesis on the RBC membrane damage and participation of SOD and heme-iron was proposed.

Animals↗

PubMed1992

[Clinical studies of recombinant human granulocyte colony-stimulating factor in elderly patients with malignant lymphoma].

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) was given in combination with chemotherapy in elderly patients (greater than or equal to 65 years old) with malignant lymphoma, and the therapeutic efficacy and the incidence of side effects were determined. The subjects consisted of 5 males and 8 females with a median age of 74 years. One patient had Hodgkin's disease and 12 had non-Hodgkin's lymphoma. Regarding lymphoma stage, 2 were in stage II, 3 were in stage III, and 8 were in stage IV. The chemotherapy used was COP-BLAM in 8 patients, COP-BLAM III in 2, IMV-triple P in 2, and ACVP-16 in 1. Treatment with rhG-CSF (1.5 micrograms/kg/day) was commenced during or after the 2nd course of chemotherapy when the neutrophil count dropped to greater than or equal to 1,000/microliters, and was continued until the recovery of either the neutrophil or leukocyte count to 10,000/microliters or 20,000/microliters, respectively. The neutrophil nadir in the non-G-CSF group was 367.3 +/- 231.6/microliters. In the G-CSF group it was 754.6 +/- 116.4/microliters for the second course, with the difference between the 2 groups being significant (p less than or equal to 0.05). Also, the following time periods were significantly shorter in the G-CSF group than the non-G-CSF group: 1) the duration of a neutrophil count less than 1,000/microliters, 2) the duration of fever (greater than or equal to 37.5 degrees C), and 3) the time to recovery from the neutrophil nadir.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1992

[Hodgkin's disease presenting with fever of unknown origin associated with granulomas of the bone marrow].

A 73-year-old man was admitted to our hospital on April 30, 1990, because of fever persisting for 18 months. Bone marrow puncture and biopsy were performed, because examination on admission revealed an elevated leukocyte count and anemia while his superficial lymph nodes, liver and spleen were not palpable. The results of the bone marrow biopsy revealed evidence of granuloma. Around May 10, the patient developed hepatosplenomegaly and enlargement of left cervical lymph nodes. Based on the results lymph node biopsy, a diagnosis of Hodgkin's disease was made, and CHOP therapy was instituted on May 20. However, the patient developed interstitial pneumonia and died on July 3. This patient's disease was manifested by fever of unknown origin. Bone marrow biopsy revealed granuloma with histiocytes predominating, and the patient subsequently developed lymph node enlargement. His disease was then diagnosed as Hodgkin's disease on the basis of a biopsy. Malignant lymphomas associated with granulomas in the bone marrow, liver or spleen are for the most part found in the advanced stage of the disease. It should be borne in mind, however, that some patients may exhibit granuloma formation in their bone marrow prior to lymph node enlargement or hepatosplenomegaly, as in the present case.

Aged↗