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Biomedical subjects

R Nakamura

Publications and source records attributed to R Nakamura.

At least 181 records · Page 10Linked to original sources

The position of symbrachydactyly in the classification of congenital hand anomalies.

The clinical features of 53 cases of intercalated hypoplasia and 113 cases of distal aplasia are reviewed and compared with each other and with 129 cases of syndactyly. Tri-, di- and mono-phalangeal symbrachydactyly, and adactyly with nubbin digits are consecutive anomalies. Transverse deficiency may result if the mesenchyme is damaged severely, and if damage is mild and formation has continued, intercalated transverse deficiency may occur. Webbing in symbrachydactyly may result from failure of the apical ectodermal ridge under the influence of damaged mesenchyme.

Female↗

Ulnar ray deficiency. A report of a family.

We report three cases of ulnar ray deficiency in one family. The father had a left ring finger deficit, and a hypoplastic little finger was amputated at childhood. His first baby had a deep cleft between the ring and little finger in the right hand, and his second baby had complete absence of the left ulna, only one metacarpal, and two digits were present on the hand. All three cases were unilaterally involved and they had no other skeletal abnormalities.

Adult↗

Palmar dermatoglyphics in congenital hand anomalies.

A palmar dermatoglyphic study of 392 hands of patients with congenital hand anomalies was performed to evaluate the number of digital triradii, the position of an axial triradius, the incidence of hypothenar patterns, the pattern intensity, and the main line index. Remarkable variations, which are rare in normal hands, were frequently observed. The results deviated from the normal range in cases of ectrodactyly and syndactyly, but were within the normal range in cases of polydactyly. The dermatoglyphics associated with each type of hand anomaly was characteristic and discriminative. Dermatoglyphics was also helpful in evaluating the function of the hand, and in estimating the time of the damage to the hand in embryogenesis.

Dermatoglyphics↗

Inhibition by lithium of cyclic GMP formation without inhibition of nitric oxide generation in the mouse neuroblastoma cell (N1E-115).

We investigated the effects of lithium ion (Li+) on muscarinic receptor-mediated nitric oxide (NO) generation, and guanylate cyclase (GCase) activation using the mouse neuroblastoma clone, N1E-115. The levels of released NO were determined by measuring the levels of nitrite/nitrate in the incubation medium, and the activity of GCase was measured with an assay for cellular cyclic [3H] GMP levels. We determined that Li+ had no effects on muscarinic receptor-activated elevation of nitrite/nitrate levels, which were significantly inhibited by 100 microM L-NG-monomethylarginine, although it has been reported that Li+ inhibits muscarinic receptor-activated cyclic GMP formation in the cells. In addition, Li+ inhibited the cyclic GMP formation induced by an NO donor, sodium nitroprusside (SNP), in both intact cells and a crude cellular homogenate; thus, the inhibition by Li+ of muscarinic receptor-mediated cyclic GMP synthesis appeared to be at the level of GCase, but not NO synthase.

Animals↗

Scaphoid fracture as a "puncher's fracture".

We investigated 18 scaphoid fractures induced by punching. The wrist position while punching was neutral to slight palmar flexion. We postulated that the mechanism of the fracture was caused by the concentration of the external force to the second metacarpus. The forces are then dispersed to the trapezium and trapezoid, which produces shear stress at the waist of the scaphoid. In spite of the differences in mechanism, the location of the fracture was similar to fractured scaphoids caused by wrist extension injuries. Regardless of the wrist positions, the carpal scaphoid is most vulnerable to fracture due to its characteristic morphology.

Adolescent↗

Spinocerebellar degenerations in Japan: a nationwide epidemiological and clinical study.

A nationwide survey of patients in Japan with spinocerebellar degenerations (SCD), including SDS and SND, was conducted from 1988 to 1989. The survey consisted of two parts. The first revealed that the estimated total number of patients with SCD in Japan was 5,050 (range: 4,100-6,000) with an estimated prevalence of 4.53 per 100,000 in 1987. The second part investigated the neurological and functional status of patients with SCD. The percentages of those belonging to each subtype of SCD were: OPCA; 34.4%, LCCA; 15.2%, MHCA; 12.6%, HHCA; 7.5%, SDS; 7.0%, HSP; 3.9%, DRPLA; 2.5%, FA; 2.4%, MJD; 2.0% and SND; 1.5%. Compared with European epidemiological studies Japan had a higher proportion of non-hereditary types of SCD. Various clinical features of SCD subtypes were compared grouped by pathological lesion and heredity. HHCA and LCCA: cerebellar ataxia predominated in all stages, and neurological signs other than cerebellar ataxia were rare. MHCA, DRPLA and MJD: in the early phase ataxia was the most common symptom in MHCA, the AC form of DRPLA and MJD, but ataxia was less common and chorea or epilepsy were often observed in ME and PH forms of DRPLA. Other frequently observed clinical features were parkinsonian rigidity in MHCA, abnormal movements and posture in DRPLA and MJD, and disturbances of eye movements in MHCA, the AC form of DRPLA and MJD. OPCA, SDS and SND: dominant clinical features were cerebellar ataxia in OPCA, autonomic disturbance in SDS, and parkinsonian rigidity in SND. FA and HSP: both were rare in Japan. Clinical features related to supra-supinal lesions were frequently observed in FA. Functional status of SCD: the severity of illness was significantly associated with the level of independence in each item of ADL. Activities not requiring dynamic balance were performed independently for a longer period than those requiring dynamic balance. Among SCD subtypes, functional prognosis was poorest in non-hereditary, multi-systemic types (OPCA, SDS and SND) followed by hereditary multi-systemic types (MHCA, DRPLA and MJD), and better in spinal types (FA and HSP) and cerebellar types (HHCA and LCCA).

Activities of Daily Living↗

Characterization of subspecies of apolipoprotein A-I-containing lipoprotein in homozygotes for familial lecithin:cholesterol acyltransferase deficiency.

We characterized the two species of lipoproteins containing apolipoprotein A-I (apoA-I), one containing only apoA-I (LpA-I) and the other containing apoA-I and apoA-II (LpA-I/A-II), in four homozygotes for familial lecithin: cholesterol acyltransferase (LCAT) deficiency. Two homozygotes lacked both LCAT mass and activity, whereas the other two had some residual LCAT mass and activity. In these patients, the amount of all apoA-I-containing lipoproteins was one fourth that of normal control subjects, and > 60% was LpA-I. The chemical composition of both LpA-I and LpA-I/A-II is characterized by markedly decreased ratios of neutral to polar lipids compared with those of normals and the sizes of LpA-I and LpA-I/A-II particles are shifted to smaller and larger diameter ranges when compared with those of normal particles. Changes in particle diameter are also reflected in slower electrophoretic mobilities of both LpA-I and LpA-I/A-II particles. All of these abnormalities were more evident in the two homozygotes who lacked LCAT activity. Incubation of LCAT-deficient plasma with LCAT markedly corrected the chemical and physical abnormalities in both LpA-I and LpA-I/A-II particles. These data, taken together, emphasize the importance of LCAT in modifying the chemical composition, size, and shape of LpA-I and LpA-I/A-II particles.

Adult↗

Psychometric equivalence of the Hasegawa Dementia Scale-Revised with the Mini-Mental State Examination in stroke patients.

Responses to the Hasegawa Dementia Scale-Revised and the Mini-Mental State Examination were examined for 49 stroke patients to investigate the psychometric equivalence between the two tests. Pearson product-moment correlation and Spearman rank-order correlation between the two tests were 0.87 and 0.78. Each test's scores significantly correlated with the Full Scale IQs on the Wechsler Adult Intelligence Scale--Revised: 0.61 for Hasegawa's Dementia Scale and 0.69 for the Mini-Mental State Examination. These values indicate that the two tests are judged comparable measures for screening cognitive impairment in stroke patients.

Aged↗

[Toxicity of AMPA, an excitatory amino acid, to rat spinal cord neurons under intrathecal administration].

The neurotoxicity mediated by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), an agonist for glutamate receptors, was investigated by infusing adult rats with this agent intrathecally for either a short term (2 hours) or a long term (7 days) using a mechanical pump or a mini-osmotic pump, respectively. In the short-term infusion group, spasticity of the hindlimbs developed during infusion at 0.5 nmol/h or more of AMPA, tremors at 50 nmol/h or more, and flaccidity at 65 nmol/h or more. One day later, flaccid paralysis of the hindlimbs and urinary incontinence were observed in the rats that received 50 nmol/h (total dose: 100 nmol) or more of AMPA. These symptoms were thought to be permanent. On the other hand, in the long-term infusion group, behavioral changes were apparent only after second postoperative day, when rats displayed hindlimb palsy or urinary incontinence. Behavioral deficits became progressively severe, and rats usually displayed both hindlimb paraplegia and urinary incontinence by the 7th postoperative day. These progressive behavioral deficits were induced in a dose-dependent manner in rats that received AMPA at doses greater than 0.1 nmol/h. Gliosis with neuronal loss involving the partial (lumbar segments) and whole (sacral segments) gray matter of the spinal cord was induced in rats that received AMPA at doses greater than 50 nmol/h in the short-term infusion group and greater than 0.1 nmol/h in the long-term infusion group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Present situation in self-injection therapy with interferon-alpha for patients with renal cell carcinoma].

Interferon-alpha (IFN alpha) is often used for the treatment of renal cell carcinomas. The injections are frequently self-administered at home. To assess how this therapy was accepted by the patient we sent out a questionnaire. For the past 2 years until March 1993, this therapy was performed in our department on 52 patients, of whom 45 were selected for the study. All patients were informed of their disease and consented to the necessity of this treatment. Thirty-eight patients answered this questionnaire. Almost all patients injected this agent mainly by themselves. These findings suggested that they regarded this therapy as a strategy to be executed by themselves for the treatment of carcinoma. The main toxic symptoms in this therapy were asthenia, fever and loss of appetite. Leukocytopenia occurred in about half of the patients, of whom 1 patient required medication because of a rapid decrease in the white blood cell count shortly after inception of this therapy. The treatment was discontinued in 50% of the patients because of these adverse effects. Systemic toxicity disappeared after cessation of IFN alpha administration. Additionally, over 80% of the patients expressed concern about effectiveness, the duration and high cost of this therapy. The patients had to be repeatedly instructed about the method of disposing used needles and syringes. This study revealed that self injection of IFN alpha, which required strict management particularly at the initiation, can be performed at home. However, countermeasures must be taken against the side actions and an optimum regimen of IFN alpha should be established as soon as possible.

Adult↗

[Epidemiological remarks on low serum cholesterol level and cancer risk of all sites].

Epidemiological studies which examine an association between low serum cholesterol level and cancer risk of all sites were reviewed and a summary of major findings are as follows: (1) In most reports, low serum cholesterol level, which associated with cancer of all sites, cancer deaths/incidence occurred within a few years after cholesterol measurement were performed. This short-term association is believed to be a preclinical cancer effect, i.e., preclinical cancer itself reduces serum cholesterol level. (2) A long-term inverse association between serum cholesterol and cancer risk of all sites was observed in some studies. This association cannot be explained by either a preclinical cancer effect or by chance. The epidemiological implications of this association was discussed in depth. (3) A long-term inverse association between serum cholesterol level and cancer mortality/incidence was observed mainly in men, but not in women. In a few studies which reported an inverse association in women, follow-up periods were rather short. (4) A few epidemiological studies conducted in Japan also detected a long-term inverse relationship between serum cholesterol level and cancer risk of all sites in men, but not in women. Since low serum cholesterol level may possibly be a risk factor for cancer of all sites, further investigation involving experimental studies on animals and longitudinal population-based study appear to be necessary for confirmation of this factor.

Adolescent↗

Episodic multiregional cortical coherence at multiple frequencies during visual task performance.

The way in which the brain integrates fragmentary neural events at multiple locations to produce unified perceptual experience and behaviour is called the binding problem. Binding has been proposed to involve correlated activity at different cortical sites during perceptuomotor behaviour, particularly by synchronization of narrow-band oscillations in the gamma-frequency range (30-80 Hz). In the rabbit olfactory system, inhalation induces increased gamma-correlation between sites in olfactory bulb and cortex. In the cat visual system, coherent visual stimuli increase gamma-correlation between sites in both the same and different visual cortical areas. In monkeys, some groups have found that gamma-oscillations transiently synchronize within striate cortex, superior temporal sulcus and somatosensorimotor cortex. Others have reported that visual stimuli produce increased broad-band power, but not gamma-oscillations, in several visual cortical areas. But the absence of narrow-band oscillations in itself does not disprove interregional synchronization, which may be a broad-band phenomenon. We now describe episodes of increased broad-band coherence among local field potentials from sensory, motor and higher-order cortical sites of macaque monkeys performing a visual discrimination task. Widely distributed sites become coherent without involving other intervening sites. Spatially selective multiregional cortical binding, in the form of broad-band synchronization, may thus play a role in primate perceptuomotor behaviour.

Animals↗

A change in soybean agglutinin binding patterns of bovine milk fat globule membrane glycoproteins during early lactation.

Milk fat globule membrane (MFGM) glycoproteins were prepared from bovine milk at different stages of early lactation. Western blot analyses using several lectins revealed that reactivity of MFGM glycoproteins, especially 47K and 80K bands, to soybean agglutinin (SBA) remarkably increased during the lactation, while no change was observed for Ricinus communis agglutinin-I (RCA-I) binding. Sialidase treatment of MFGM glycoproteins revealed that the number of SBA-positive bands and the amount of SBA-positive oligosaccharides in these bands are increased during the lactation. Since SBA binds N-acetylgalactosamine terminated oligosaccharides, the results indicated that N-acetylgalactosaminylation of bovine MFGM glycoproteins is stimulated during the lactation.

Animals↗

Different appearance of gamma delta T cells during salmonellosis between Ityr and Itys mice.

Ity gene, which is believed to be a single gene on proximal mouse chromosome 1, determines susceptibility to Salmonella infection. We have recently demonstrated that the gamma delta T cells specific for purified protein derivative appear at the early stage after infection with Salmonella choleraesuis strain 31N-1 (avirulent strain) in mice. In the present study, we compared the appearance of the gamma delta T cells in Ityr and Itys mice after infection with S. choleraesuis in an attempt to elucidate the role of the gamma delta T cells in the in vivo effect of the Ity locus on murine salmonellosis. The numbers of gamma delta T cells in the peritoneal cavity and liver were significantly larger in DBA/2 (Ityr) mice than those in BALB/c (Itys) mice after infection with a sublethal dose of S. choleraesuis. C.D2 Ityr mice, which are BALB/c mice with Ityr allele, also showed a significant increase in the number of the gamma delta T cells at the early stage after infection. Similar results in different appearances of the gamma delta T cells could be obtained between BALB/c and DBA/2 mice after infection with Mycobacterium bovis, bacillus Calmette-Guérin. The peritoneal adherent cells of DBA/2 mice infected with S. choleraesuis, which expressed a large amount of heat shock/stress protein (hsp) homologous to the mycobacterial 65-kDa hsp, induced significantly higher level of expansion of the peritoneal gamma delta T cells in normal mice in vivo and in vitro than did those of BALB/c mice infected with S. choleraesuis, which expressed a lesser amount of the hsp. These results suggest that the Ity locus may be closely related to the expression of hsp by macrophages after infection with Salmonella, which in turn stimulate the gamma delta T cells in the host during an early phase of salmonellosis.

Animals↗

MR imaging findings of tremors associated with lesions in cerebellar outflow tracts: report of two cases.

Two cases with severe tremors were studied by means of electromyograms using surface electrodes and also by magnetic resonance (MR) imaging. The first case was associated with multiple sclerosis and demonstrated a severe postural cerebellar tremor and an alternate activation of antagonist muscles in the right arm. The second case, with hemorrhage in the brainstem, demonstrated a severe tremor at rest and mixed synchronous and alternating activation of antagonist muscles in the left forearm. MR imaging studies localized lesions possibly responsible for these tremors. In the first case a lesion was located in the superior cerebellar peduncle just under the decussation, and in the second case a lesion was found between the red nucleus and the thalamus, with possible involvement of both the cerebellothalamic and nigrostriatal pathways. The first case accords with the theory that a lesion located in the dentate nucleus and its projection can cause severe postural cerebellar tremor. The lesion demonstrated in the second case may be responsible for "cerebellar tremor at rest" or "static (resting) cerebellar tremor."

Adult↗

Gene structure and expression of rice seed allergenic proteins belonging to the alpha-amylase/trypsin inhibitor family.

Genomic and two novel cDNA clones for rice seed allergenic protein (RA) belonging to the alpha-amylase/trypsin inhibitor family were isolated and their nucleotide sequences determined. Ten cysteine residues deduced from nucleotide sequences were completely conserved among three cDNA clones including a clone, RA17, reported previously. One genomic clone, lambda 4, contained two RA genes, RAG1 and RAG2. Although RAG1 was cloned at the 5' portion only, two RA genes were arranged divergently. Nucleotide sequencing and DNA blotting analyses showed that RA are encoded by a multigene family consisting of at least four members. The transcriptional initiation site of RAG1 was localized at A, 26 bp upstream of the putative translational initiation codon, ATG, by the primer extension assay. The putative TATA box and CAAT box existed about 45 bp and 147 bp upstream of the transcription initiation site, respectively. A conserved sequence (ATGCAAAA) which was similar to the sequence (TGCAAAA) identified in rice glutelin promoters was observed in the 5' region of the two genes. In addition, RNA blotting analyses provided that RA genes specifically expressed in ripening seed and their transcripts accumulated maximally between 15 and 20 days after flowering.

Allergens↗