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Biomedical subjects

C Uchiyama

Publications and source records attributed to C Uchiyama.

33 records · Page 2Linked to original sources
PubMed1993

Evaluation of two new neuropsychological tests designed to minimize cultural bias in the assessment of HIV-1 seropositive persons: a WHO study.

In the course of the preparatory work for the WHO cross-cultural study on the neuropsychiatric aspects of HIV-I infection, two new neuropsychological tests (the WHO/UCLA Auditory Verbal Learning Test and the Color Trails 1 & 2) were developed. The evaluation of these tests was performed at four sites, two in developed and two in developing countries. The data obtained suggest that the tests are more culture fair than others currently used to assess the same functional domains, that they are sensitive to HIV-1-associated cognitive impairment, and that this sensitivity "holds" across different cultures.

Journal Article↗
PubMed1991

Novel gene sequences expressed by human melanoma cells identified by molecular subtraction.

Despite the variety of approaches used, only a limited number of tumor-associated antigens have been described for each histological type of tumor. In this report, we present a new strategy involving molecular subtraction to identify novel melanoma-associated gene sequences. Toward this end, 156 complementary DNA clones were isolated with a subtracted melanoma complementary DNA probe (melanoma minus lung carcinoma) after screening 2 x 10(4) independent recombinants of a melanoma expression library by in situ plaque hybridization. These clones were then polymerase chain reaction amplified, screened for duplication, and categorized into 53 discrete genes. By applying poissonian distribution to the numbers of duplicate isolates, we found most of the genes to be rare messages, present at less than 1 copy/200 molecules of mRNA in a typical somatic cell. Messages specific for a type of tissue are usually expressed in this range. The expression of the 53 genes was further studied in human tumor cell lines and normal tissues. Partial sequence data obtained for 20 complementary DNA clones revealed 8 novel human genes. The mRNA transcripts for 5 of the novel genes were identified by Northern blot analysis. Thus, molecular subtraction appears to be applicable for the identification of novel tumor-associated sequences. Some of the potential advantages and limitations of this technology are discussed, including its application to the molecular characterization of immunogenic melanoma-associated antigens.

Antigens, Neoplasm↗
PubMed1991

A case of citrullinemia with abnormal messenger RNA for argininosuccinate synthetase.

A male neonate, thus far healthy and fed with breast milk, developed rapidly increasing apathy on the third day of life. Sucking became poor and hyperhidrosis was present. Hyperammonemia (3,305 micrograms/dl) was noted. He became comatose and died on the fourth day. There was a profound derangement of amino acid concentration in the body fluids, with highly elevated citrulline levels (4.70 mumols/ml in serum and 8.47 mumols/ml in urine). Autopsy showed diffuse pulmonary bleeding, as the only noteworthy pathological finding. The liver contained no detectable argininosuccinate synthetase (ASS) activity. The defect of ASS in the present case was not due to a reduced amount of ASSmRNA, but its structure was found to be abnormal; it was approximately 1.57 kb in length due to a defect of about 0.1 kb near the 3' end of the coding region.

Amino Acid Metabolism, Inborn Errors↗
PubMed1991

[Central visual fields in pure alexia "without hemianopsia"--visual dysfunction in the right hemifield, and alexia for "kana" words in the left].

Following a left occipito-temporal subcortical hematoma, a 57-year-old, right-handed man developed pure alexia that was more prominent in kana words, especially in kana nonwords, than in kanji letters. Although a kinetic perimetry with a Goldmann perimeter showed his visual fields to be full, a static perimetry with a Humphrey visual field analyzer disclosed decreased visual sensitivity in the right visual field in its central 30 degrees. In addition, a tachnistoscopic examination with Landolt rings revealed his visual acuity (the ability of two points discrimination) to have decreased in the right half of his central visual filed in its 3 degrees. In the right central vision, he was unable to recognize the letters, pictures or colors presented by the tachistoscope. Concerning the reading, the more letters in kana words or the higher the number of strokes in kanji letters, the more difficulty he experienced in orally reading both kana and kanji. On the contrary, in the left central vision, kanji reading was not so affected by an increased number of strokes as the kana-word reading which became difficult when the number of the letters increased. CT scan showed subcortical hematoma in the left occipitotemporal region. Magnetic resonance imaging 3 months after onset revealed a localized injury in the region between the left postero-inferior temporal lobe and the infero-lateral occipital lobe, including the fusiform gyrus. None of the splenium, the lingual gyrus or the optic area were affected. The spared structures also included the angular gyrus, the Wernicke area and their subcortical white matter.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral Hemorrhage↗
PubMed1990

External validity of the new Devereux Adolescent Behavior Rating scales.

The discriminant and concurrent validity of the five new scales for the Devereux Adolescent Behavior Rating Scale (DAB) was explored using a heterogeneous sample of psychiatric and substance abuse patients. Consistent with predictions, the substance abuse patients scored higher on the Acting Out Behaviors (AOB) and Heterosexual Interests (HI) scales, and psychiatric patients scored higher on the Psychotic Behaviors scale. Gender differences also were found, including boys being rated higher on Acting Out Behaviors, and girls higher on Heterosexual Interests. The new DAB scales demonstrated sufficient concurrent validity using a thorough record review and a patient rating scale (the Child Behavior Checklist [CBCL]). The Neurotic/Dependent Behaviors scale (NDB) showed a consistent relationship with substance abuse and several other measures of more externalizing behaviors, in addition to the predicted relationships with anxious, tense, and dependent behaviors. The Withdrawn/Timid Behaviors scale (WTB) proved to be a purer measure of internalizing behaviors in both sexes.

Acting Out↗
PubMed1989

Assessment of life events during adolescence: the use of self-report inventories.

The assessment of stressful life events during adolescence is important to both research and clinical practice. Stressful events are studied to determine their etiological significance in physical and mental illnesses, and also their relevance in the clinical assessment of individual patients. In recent years, a number of self-report inventories of life events for adolescents have been developed, some very carefully, others as one-time endeavors. This article reviews these measures, with an emphasis on the conceptual and methodological issues which created problems in earlier inventories. These issues need to be considered when choosing an instrument to study or assess stressful life events in adolescents.

Adolescent↗
PubMed1987

Structure of an abnormal messenger RNA for argininosuccinate synthetase in citrullinemia.

The structural abnormality of mRNA for argininosuccinate synthetase (ASS) and the structure of immune cross-reactive material for ASS (ASS-CRM) in the liver of a patient with type III citrullinemia were analyzed using dot and Northern blot hybridization, S1 nuclease analysis, and a sensitive enzyme-linked immunosorbent assay. The patient's liver contained no detectable ASS activity, the ASS-CRM content was about 0.5% of that in the control and the ASS mRNA content was almost normal. The ASS mRNA of the case was found to have an apparent structural abnormality; approximately 1.57 kb in length caused by a defect of about 0.1 kb near the 3' end of the coding region. Furthermore, gel filtration analysis revealed that the ASS-CRM had a molecular weight indistinguishable from the control ASS. These results indicate that the abnormal mRNA of the patient was translated in vivo to an immune-cross-reactive protein that was able to form a quaternary structure.

Amino Acid Metabolism, Inborn Errors↗
PubMed1981

Subcellular localization and properties of N-acetylglutamate synthase in rat small intestinal mucosa.

N-Acetylglutamate synthase [EC 2.3.1], which catalyzes the synthesis of N-acetylglutamate, a key effector of carbamoyl-phosphate synthase (ammonia) [EC 6.3.4.16] in the liver of ureotelic animals, was demonstrated to be present in rat small intestinal mucosa. The activity of the enzyme was estimated to be 0.17 nmol N-acetylglutamate formed X (g mucosa)-1 X min-1 at 25 degrees C. Little activity was found in the muscle layer and serosa of the small intestine. The intestinal villous cells were separated from everted intestine, disrupted by nitrogen cavitation, and fractionated into nuclear, mitochondrial, microsomal, and soluble fractions. The mitochondria isolated by this method retained integrity of respiratory function. The mitochondrial fraction was further subjected to isopycnic centrifugation using Percoll (colloidal silica coated with polyvinylpyrrolidone). The activities of N-acetylglutamate synthase and the first two urea cycle enzymes, carbamoylphosphate synthase (ammonia) and ornithine carbamoyltransferase [EC 2.1.3.3], were cofractionated with mitochondrial marker enzymes during the cell fractionation and the isopycnic centrifugation. N-Acetylglutamate synthase, purified 8-fold from the acetone powder extract of small intestinal mucosa, had a high substrate specificity for L-glutamate and acetyl-CoA. The synthase reaction fitted normal Michaelis-Menten kinetics with respect to both L-glutamate (apparent Km, 2.5 mM) and acetyl-CoA (apparent Km, 0.8 mM). L-Arginine stimulated the enzyme activity by increasing the maximal velocity with no effect on apparent Km values for the substrates. These properties were similar to those of the rat liver enzyme (Shigesada & Tatibana (1978) Eur. J. Biochem. 84, 285-291). These results suggest that a function of the intestinal N-acetylglutamate is to activate carbamoyl-phosphate synthase (ammonia) and to allow citrulline synthesis in the tissue.

Acetyltransferases↗
PubMed1980

Ornithine carbamoyltransferase deficiency: coexistence of active and inactive forms of enzyme.

Kinetic and molecular properties of liver ornithine carbamoyltransferase from a female patient with the enzyme deficiency were studied. The enzyme activity in the patient was 9% of that in controls. Kinetic properties of the enzyme from the patient appeared to be identical to those of the control enzyme; apparent Km values for L-ornithine and carbamoyl-phosphate at pH 7.2 were 1.3 mmol/l and 7.9 mumol/l, respectively. Patient and control livers contained similar amounts of protein cross-reactive with antibody to the bovine enzyme. No difference in the subunit size was observed between the patient enzyme and the control enzyme. When extracts of control liver were analyzed by isoelectric focusing, a major peak of immunoreactive protein with a pI value of 7.3 and a minor peak with a pI value of 6.8 were observed, and both forms were enzymatically active. On the other hand, extracts of the patient's liver gave a major peak of immunoreactive protein with a pI value of 7.0 and a minor one with a pI of 6.8; the minor form was enzymatically active while the major one showed little or no activity. These results indicate that the patient's liver contained an inactive form of ornithine carbamoyltransferase in addition to an active form of the enzyme, and may reflect the X-linkage of the enzyme at the molecular level.

Female↗