Biomedical subjects

M Fujioka

Publications and source records attributed to M Fujioka.

At least 127 records · Page 7Linked to original sources

PubMed1996

Magnetic resonance imaging of clival marrow in patients with anorexia nervosa.

Hematological abnormalities, commonly associated with anorexia nervosa (AN) patients, are thought to be the results of serous atrophy in the bone marrow. Magnetic resonance imaging (MRI) has been utilized to ascertain T1 and T2 prolongation of marrow intensity in the lumbar spine, pelvis and proximal femora. The results correlate well with the severity of hematological abnormalities, and body mass index. More importantly, the propensity for peripheral marrow involvement of T2 prolongation contrasts with the axial involvement in other marrow disorders. MRI undertaken in patients with AN to exclude hypothalamic tumor showed that the clival marrow was equivalent to the peripheral marrow. The signal pattern of clival marrow on sagittal T1 weighted MR images was evaluated in four teenage female patients with AN complicated by hematological abnormalities. Although the clival marrow intensity should be uniformly high in teenagers, three patients, two with pancytopenia and one with leukopenia and anemia, exhibited homogeneous low intensity. One patient who had leukopenia only and the highest body mass index, showed inhomogeneous low intensity. The signal changes returned to normal in all patients but one, who died before examination after 6-11 months, at which time the others had almost recovered their original weight and normal hemogram. T1 prolongation in the clival marrow represents bone marrow dysfunction and the inhomogeneity of the signal change may imply relative preservation of hematopoiesis and body fat composition. Lack of knowledge of this phenomenon may lead to diagnostic confusion with other marrow disorders on cranial MRI.

Adolescent↗

PubMed1996

Drosophila Paired regulates late even-skipped expression through a composite binding site for the paired domain and the homeodomain.

The even-skipped (eve) pair-rule gene plays a key role in the establishment of the anterior-posterior segmental pattern of the Drosophila embryo. The continuously changing pattern of eve expression can be resolved into two phases. Early expression consists of seven broad stripes in the blastoderm embryo, while late expression, which occurs after cellularization, consists of narrow stripes with sharp anterior borders that coincide with the odd-numbered parasegment boundaries. Previous studies have shown that these two phases are controlled by separate classes of cis elements in the eve promoter. Early stripes are expressed by multiple stripe-specific elements under the control of maternal-effect genes and gap genes, while late stripes are expressed by a single regulatory element, the 'late element', under the control of pair-rule genes including eve itself. We report here that paired (prd), a pair-rule gene which had been considered to be below eve in the regulatory hierarchy of pair-rule genes, in fact plays a critical role in the regulation of late eve expression. Transgenic analysis shows that this regulation is largely mediated by an evolutionarily conserved sequence within the late element termed PTE (Paired Target Element). In vitro analysis shows that the Prd protein binds strongly to this sequence. Interestingly, PTE contains juxtaposed binding sites for the two DNA-binding domains of the Prd protein, the paired domain and the homeodomain. Mutagenesis of either binding site leads to significant reduction in the activity of the late element, indicating that both DNA-binding domains in the Paired protein are required for regulation.

Animals↗

PubMed1996

Both the paired domain and homeodomain are required for in vivo function of Drosophila Paired.

Drosophila paired, a homolog of mammalian Pax-3, is key to the coordinated regulation of segment-polarity genes during embryogenesis. The paired gene and its homologs are unusual in encoding proteins with two DNA-binding domains, a paired domain and a homeodomain. We are using an in vivo assay to dissect the functions of the domains of this type of molecule. In particular, we are interested in determining whether one or both DNA-binding activities are required for individual in vivo functions of Paired. We constructed point mutants in each domain designed to disrupt DNA binding and tested the mutants with ectopic expression assays in Drosophila embryos. Mutations in either domain abolished the normal regulation of the target genes engrailed, hedgehog, gooseberry and even-skipped, suggesting that these in vivo functions of Paired require DNA binding through both domains rather than either domain alone. However, when the two mutant proteins were placed in the same embryo, Paired function was restored, indicating that the two DNA-binding activities need not be present in the same molecule. Quantitation of this effect shows that the paired domain mutant has a dominant-negative effect consistent with the observations that Paired protein can bind DNA as a dimer.

Animals↗

PubMed1996

[Questionnaire survey of AIDS examination recipients at government-run public health center regarding AIDS awareness promotion and HIV examinations].

An anonymous questionnaire survey was conducted among persons who had undergone screening for AIDS at public health centers under the auspices of 7 local government bodies (Hokkaido, Metropolitan Tokyo, Aichi Prefecture, Osaka Prefecture, Kobe City, Saga Prefecture, Okinawa Prefecture). There were 1,230 replies, for a response rate of 46.8%. Questions in the survey pertained to general knowledge of AIDS, information desired by the recipients, desired ways to foster awareness, and a desirable examination system. A comparison was made in terms of gender, marriage status (married, single) and age (less than 40 years of age, more than 40 years of age), respectively. The survey results were as follows. 1. Concerning the infection route, accurate response rate was low with regard to the mother-child infection, mosquito transmission, and use of contaminated needles. 2. Desired methods to promote AIDS awareness expressed among replies were given in the following order or frequency: "information via radio and TV," "spread of knowledge through telephone consultation," and "holding an AIDS Week or similar kinds of campaigns." 3. Information sought by respondents frequently included AIDS treatment, pathology, and spread. This trend was most obvious among those under 40 years of age. 4. As for the AIDS examination system, replies most often reflected the hope that the examination site would be the Public Health Center, the charge would be gratis, and that one could be examined at night during the week, and on days off. 5. For those undergoing examination where there was no actual concern of possibility of HIV infection, single persons, accounted for around 80% of the overall. 6. More than half of those who had been examined mentioned having experienced concerns about maintaining confidentiality at the time they were examined.

Acquired Immunodeficiency Syndrome↗

PubMed1996

[Environmental factors influencing sensitization and onset of Japanese cedar pollinosis among junior high school students].

Japanese cedar pollinosis has shown large increases especially in city areas, rather than in the rural, with increases being remarkable especially among people of young age. In order to elucidate factors for sensitization and onset of Japanese cedar pollinosis, a questionnaire survey was conducted and serum IgE antibody levels examined in junior high school students living in three different areas, i.e., city, seaside and mountainous areas in Aichi prefecture. Prevalence rate of Japanese cedar pollinosis, estimated from the number of students having both nasal or ocular allergic symptoms and positive RAST, was the 30.1% in the mountainous area with high Japanese cedar pollen count, being greater than the 15.3% in the city area and the 5.8% in the seaside area, both with low pollen counts. Among the students showing high serum mite (Dermatophagoides farinae) antibody levels, greater positive rates for sensitization to Japanese cedar or orchard grass pollens was observed, compared to mite-unsensitized students. This result suggests that sensitization to seasonal antigens may be corresponding to the capability for sensitization to the mites. Besides this finding, the analysis of replies to the questionnaires showed that students living in concrete or steel-frame buildings had greater serum levels of antibody to Japanese cedar pollen than those living in wood buildings, indicating a possible relationship between the pollen sensitization and indoor environments.

Adolescent↗

PubMed1996

[A case of cystic hemangioblastoma of the medulla oblongata].

Cystic hemangioblastoma of the brain stem is an extremely rare clinical entity. Only eight cases have been reported in the literature. This is a report of a case of successful extirpation of a cystic hemangioblastoma of the medulla oblongata. A 47-year-old man was admitted to our clinic with the complaint of progressive numbness on his left upper limb since January 1995. Neurological examination revealed numbness and decreased vibration sensation on his left upper limb. MRI showed a cystic 1.5 x 2.0 cm lesion on the medulla oblongata, and with administration of Gd-DTPA, a small mass lesion on the dorsolateral side of the medulla oblongata. Left vertebral angiogram revealed a tumor fed directly from the left vertebral artery. An operation was performed using a suboccipital approach. The dorsal surface of the medulla was swollen edematously, suggesting the site of a cyst, which emptied by means of opening the wall. The reddish tumor was embedded on the left dorsolateral surface of the medulla oblongate. A total extirpation of the tumor was carried out under microscopic procedure. Histologically, the tumor was diagnosed as a hemangioblastoma. The patient was free from his distressing numbness immediately after the operation, and discharged without neurological deficit.

Brain Neoplasms↗

PubMed1995

Recombinant production and biological properties of rat cytokine-induced neutrophil chemoattractants, GRO/CINC-2 alpha, CINC-2 beta and CINC-3.

Recently we found four cytokine-induced neutrophil chemoattractants, CINC-1, CINC-2 alpha, CINC-2 beta and CINC-3/macrophage inflammatory protein 2 (MIP-2), in conditioned medium of granulation tissue obtained from carrageenin-induced inflammation in rats [Nakagawa, H., Komorita, N., Shibata, F., Ikesue, A., Konishi, K., Fujioka, M. & Kato, H. (1994) Biochem. J. 301, 545-550]. In the present report, we describe recombinant production of CINC-2 alpha, CINC-2 beta and CINC-3 in Escherichia coli, and biological properties of these chemokines. Neutrophil chemotactic activities of CINC-2 alpha and 2 beta in vitro were the same as the activity of CINC-1. CINC-3 had an activity comparable to other CINCs, but showed a decrease at high concentrations. Stimulation of neutrophils with CINCs induced an increase in intracellular [Ca2+] dose-dependently. CINC-3 was more potent than the other CINCs and still induced an increase in intracellular [Ca2+] in rat neutrophils stimulated first with other CINCs. CINC-2 alpha, CINC-2 beta and CINC-3 induced a comparable response to CINC-1 in the release of cathepsin G from rat neutrophils. Injection of CINC-2 alpha, 2 beta and 3 into preformed air-pouch on the back of rat induced infiltration of neutrophils to an extent similar to that caused by the injection of CINC-1. These data indicate CINC-2 alpha, 2 beta and 3 as well as CINC-1 are chemoattractants specific for neutrophil in vivo.

Animals↗

PubMed1995

Early even-skipped stripes act as morphogenetic gradients at the single cell level to establish engrailed expression.

even-skipped (eve) has been proposed to set up parasegment borders at the anterior edge of each of its seven stripes by providing a sharp expression boundary, where engrailed is activated on one side and wingless on the other. By expressing bell-shaped early eve stripes without the sharp boundary provided by narrow, late stripes, we find that the early gradient is sufficient for generating stable parasegment borders. Based on several lines of evidence, we propose that the anterior portion of each early stripe has morphogenic activity, repressing different target genes at different concentrations. These distinct repression thresholds serve to both limit and subdivide a narrow zone of paired expression. Within this zone, single cell rows express either engrailed, where runt and sloppy-paired are repressed, or wingless, where they are not. While the early eve gradient is sufficient to establish parasegmental borders without refined, late expression, late eve expression has a role in augmenting this boundary to provide for strong, continuous stripes or engrailed expression. In addition, we show that the early eve gradient is sufficient, at its posterior edge, for subdividing the ftz domain into engrailed expressing and non-expressing cells.

Animals↗

PubMed1995

Trigeminal neuralgia associated with venous angioma--case report.

A 35-year-old male presented with trigeminal neuralgia associated with venous angioma at the root entry zone. Magnetic resonance imaging and angiography demonstrated a venous angioma with a dilated petrosal draining vein, and displacement of the anterior inferior cerebellar artery (AICA). The AICA and dilated petrosal vein were both decompressed, resulting in complete relief from symptoms of trigeminal neuralgia for 30 months. Microvascular decompression rather than resection of venous angioma is recommended for treatment of such cases. The possibility of a venous anomaly should be considered in younger patients with trigeminal neuralgia.

Adult↗

PubMed1995

[A case of multilocular thymic cyst with myasthenia gravis].

We reported a case of 53-year-old male who was admitted to our hospital for ptosis and difficulty in chewing. Because of positive for Tensilon test and high dose anti-acetylcoline receptor antibody, we established diagnosis for myasthenia gravis. Additionally he was pointed out a cystic lesion at anterior superior mediastinum on CT and MRI. As a result we diagnosed him as thymic cyst with myastenia gravis. The extended thymectomy was performed. Histological examination revealed that the mass was a multilocular thymic cyst which is reported by Suster, who suggested that the multilocular thymic cyst arises from processes of reactions to an acquired inflammatory change. There was no report for cases of multilocular thymic cyst with myastenia gravis. MTC-like changes are sometimes presented in association with thymic Hodgkin's disease or thymic seminoma. Malignant transformation of thymic cyst were also reported. So careful examination and evaluation for cystic lesion within thymus are required.

Humans↗

PubMed1995

[Acute encephalitis and bacterial meningitis in children in Aichi Prefecture (1984-1993)].

A survey was performed of acute encephalitis and bacterial meningitis in infancy and childhood from 1984 to 1993 using a questionnaire directed to departments of pediatrics in large hospitals in Aichi prefecture. The case records for 391 patients with acute encephalitis including related diseases and 328 patients with bacterial meningitis were obtained from 63 hospitals. Of 391 patients with acute encephalitis, 224 were male and 167 were female. Of 328 patients with bacterial meningitis, 200 were male and 128 were female. Sex ratio were 1.3, 1.6 respectively. Of the patients, 52.4% of encephalitis and 84.8% of meningitis were under 4 years of age and 0 year olds made up 53.7% of the latter. The causes of these diseases were confirmed in 38.7% and 82.9% of the encephalitis and meningitis patients, respectively, etiologically. In encephalitis, rubella virus was the most frequent with 29 cases, followed by measles virus (27 cases), herpes simplex virus (24) and varicella-zostervirus (19). In meningitis H. influenzae (95 cases), S. pneumoniae (56), Group B streptococcus (41) and E. coli (27) were frequently diagnosed. These diseases showed respective patterns of age distribution and clinical course, and moreover, the increases in their onset were clearly related to the prevalence of causal infections. Therefore, the results of this study should be utilized in the development of administrative measures for prevention of these diseases.

Acute Disease↗

PubMed1995

[AIDS/HIV related knowledge, attitude and behavior of acupuncture therapists in Aichi Prefecture].

To promote AIDS prevention measures in Japan, the actual state of knowledge, attitudes and behaviors (KAB) of workers at risk for HIV infection requires clarification. In the present study, acupuncture therapists in Aichi Prefecture were evaluated for level of their KAB. By using a self-administered questionnaire, the KAB condition of 500 acupuncture therapists was surveyed from September-November in 1993. Responses from 494 (98.8%) were available for analysis. Results showed that knowledge level on general issues regarding HIV epidemics was good. The main sources for information on AIDS/HIV were TV, general lectures, public reports and magazines. More than 80% of acupuncture therapists sterilize their needles by autoclave or boiling and 60% of them use disposable needles. Furthermore, 97% of the therapists reported utilizing one or the other of these methods. More than a half of them have participated in AIDS education programs. While about 30% of them responded that they are able to accept HIV carriers as clients, 20% of them expressed negative responses. There appears to be a discrepancy between their level of knowledge of HIV transmission routes and their practical attitude towards clients with AIDS and/or HIV carriers. A more appropriate education program based on behavioral science is desirable to lessen discrepancy distance between general knowledge and preferable behavior regarding AIDS/HIV.

Acquired Immunodeficiency Syndrome↗

PubMed1994

Identification of cytokine-induced neutrophil chemoattractants (CINC), rat GRO/CINC-2 alpha and CINC-2 beta, produced by granulation tissue in culture: purification, complete amino acid sequences and characterization.

Four basic neutrophil chemotactic factors (chemokines) have been purified from conditioned medium of granulation tissue obtained from carrageenin-induced inflammation in the rat. On the basis of their N-terminal amino acid sequences, one of the chemokines was identical with rat GRO/cytokine-induced neutrophil chemoattractant (CINC) which we reported previously, and another was identical with rat macrophage inflammatory protein-2 (MIP-2). Two other chemokines were novel chemoattractants related to MIP-2. The novel chemokines are referred to as rat GRO/CINC-2 alpha and CINC-2 beta, and consequently CINC and rat MIP-2 are renamed rat GRO/CINC-1 and CINC-3 respectively. The complete amino acid sequences of purified CINC-2 alpha and CINC-3 were determined by analysis of the fragments isolated from proteinase V8-treated CINCs. The cDNA for CINC-2 beta was cloned by reverse transcription/PCR amplification using specific primers starting with total RNA extracted from lipopolysaccharide-stimulated rat macrophages. A comparison of the amino acid sequence encoded by the cDNA with the N-terminal amino acid sequence of purified CINC-2 beta revealed that mature CINC-2 beta is a 68-residue chemoattractant produced by cleavage of a 32-residue signal peptide. The difference in amino acid sequences between CINC-2 alpha and CINC-2 beta consisted of only three C-terminal residues. Rat GRO/CINC-2 alpha is a major chemokine, and the four purified chemokines have similar chemotactic activity, suggesting that they contribute to neutrophil infiltration into inflammatory sites in rats.

Amino Acid Sequence↗

PubMed1994

Rat guanidinoacetate methyltransferase. Effect of site-directed alteration of an aspartic acid residue that is conserved across most mammalian S-adenosylmethionine-dependent methyltransferases.

Most mammalian S-adenosylmethionine (AdoMet)-dependent methyltransferases have a conserved aspartate residue in a sequence oDso (o denotes a hydrophobic amino acid and s denotes a small neutral amino acid). Rat guanidinoacetate methyltransferase has two aspartate residues (Asp-129 and Asp-134) conforming to the motif in close proximity to Tyr-136 that is photoaffinity-labeled by AdoMet (Takata, Y., and Fujioka, M. (1992) Biochemistry 31, 4369-4374). In order to investigate the role of these residues, we prepared variant forms of the enzyme by oligonucleotide-directed mutagenesis. Conversion of Asp-129 to asparagine or alanine resulted in a functional enzyme. Alteration of Asp-134 to glutamate (D134E) and asparagine (D134N) decreased activity, and replacement with alanine (D134A) led to inactivation. Decreases of 3- and 120-fold were found for kcat values of D134E and D134N, respectively. The Km values of D134E for AdoMet and those for guanidinoacetate were increased about 160- and 80-fold over the respective values of wild type. The corresponding increases in D134N were 800- and 50-fold, respectively. Conservative changes of the residues flanking Asp-134 had little effect on activity. Guanidinoacetate methyltransferase obeys an ordered Bi Bi mechanism in which AdoMet binds first. Thus, the large decreases in kcat/Km values for AdoMet indicate that Asp-134 is crucial for binding AdoMet. Spectroscopic studies indicated that the amino acid substitutions of Asp-134 resulted in no significant changes in the secondary and tertiary structures, and urea denaturation experiments showed that the altered enzymes were not destabilized.

Amino Acid Sequence↗

PubMed1994

The role of cysteine 78 in fluorosulfonylbenzoyladenosine inactivation of rat liver S-adenosylhomocysteine hydrolase.

Inactivation of rat liver S-adenosylhomocysteine hydrolase by the site-directed reagent 5'-p-fluorosulfonylbenzoyladenosine (FSBA) is associated with the formation of a disulfide bond between Cys-78 and Cys-112 (Takata, Y., and Fujioka, M. (1984) Biochemistry 23, 4357-4362; Gomi, T., Ogawa, H., and Fujioka, M. (1986) J. Biol. Chem. 261, 13422-13425). To characterize the inactivation mechanism more precisely, the properties of four hydrolase proteins mutated at Cys-78 or Cys-112 were compared to those of the wild-type enzyme. When Cys-78 was mutated to either a serine or an alanine, proteins with greatly reduced enzymatic activity were obtained, large effects on kinetic constants were observed, and enzymatic activity was not affected by incubation with FSBA. When Cys-112 was mutated to either a serine or an alanine, the activity was similar to the wild-type protein, only small changes in the kinetic constants were observed, and the enzyme was inactivated more rapidly upon incubation with FSBA. FSBA inactivation of the C112A mutant protein was accompanied by the formation of a disulfide between Cys-78 and Cys-52. The data indicate that FSBA initially reacts with Cys-78 and that Cys-78 has an important role in the structure of the enzyme.

Adenosine↗

PubMed1994

Diurnal variation of the serine dehydratase mRNA level in rat liver.

Serine dehydratase mRNA in the livers of rats maintained on laboratory chow (containing 22% protein) under a 12-h light (7:00-19:00)/12-h dark (19:00-7:00) cycle showed a daily oscillation that was maximal at 19:00 and minimal at 7:00 with an amplitude of more than 20-fold. The feeding of high-protein diets (60 and 91% casein) did not affect the oscillation phase. Virtually identical oscillatory phases for the mature serine dehydratase mRNA and its precursor RNAs, and the results of nuclear run-off transcription assays indicated that the oscillation was generated at the level of transcription. Similar oscillation patters were seen in adrenalectomized, starved, or diabetic rats. However, the mRNA oscillation was not precisely reflected in the oscillation of enzyme activity or enzyme protein in both the phase and the amplitude. Rats maintained on laboratory chow under constant light for 2 weeks still showed mRNA oscillation with a peak at 3:00, whereas rats exposed to constant light and fed between 7:00 and 9:00 exhibited an oscillation peak at 3:00-7:00. Under the conditions of a 12-h light/dark cycle and a 2-h restricted feeding between 7:00 and 9:00, a broad peak was seen at 23:00-3:00. These results indicate that the rhythmic expression of serine dehydratase gene is controlled by both meal-responsive and photoresponsive regulators.

Animals↗

PubMed1994

Changes in the basal ganglia and thalamus following reperfusion after complete cerebral ischaemia.

We report specific changes bilaterally in the basal ganglia and thalamus following reperfusion after complete cerebral ischaemia. A 69-year-old man, resuscitated after cardiac arrest, showed symmetrical low-density lesions in the head of the caudate nucleus and lentiform nucleus on CT. MRI revealed methaemoglobin derived from minor haemorrhage in the basal ganglia and thalamus, not evident on CT. We suggest that this haemorrhage results from diapedesis of red blood cells through the damaged capillary endothelium following reperfusion.

Aged↗

PubMed1994

Acylcarnitine profile in tissues and body fluids of biotin-deficient rats with and without L-carnitine supplementation.

Since biotin-deficient (BD) rats are a good animal model for human multiple carboxylase deficiency and have low plasma free carnitine levels, short-chain acylcarnitine profiles in biotin-deficient rats with L-carnitine supplementation (BDC rats) and BD rats were investigated by fast-atom bombardment and tandem mass spectrometry and gas chromatography/mass spectrometry. By the latter method, 3-hydroxyisovalerylcarnitine was identified in BD rats, and showed the greatest accumulation among short-chain acylcarnitines in tissues of BD rats, while the tissue levels of propionic acid were more markedly elevated than those of 3-hydroxyisovaleric acid. The tissue levels of 3-hydroxyisovaleryl-carnitine were significantly lower and those of propionyl-carnitine were somewhat higher in BDC rats than in BD rats, while the tissue levels of propionic acid and 3-hydroxyisovaleric acid in BDC rats were lower than those in BD rats. These changes were more apparent in kidney than in other tissues. The amounts of urinary excretion of acylcarnitines were markedly larger, and those of 3-hydroxyisovaleric acid were somewhat smaller in BDC rats than in BD rats, while those of propionic acid were very low in BD and BDC rats as compared with those of 3-hydroxyisovaleric acid. It seems that the relationship between the concentrations of 3-hydroxyisovalerylcarnitine and those of propionylcarnitine reflects the unique metabolism of the related metabolites in tissues, especially in kidney, which may be influenced by their urinary excretion and the availability of free carnitine. These data in biotin deficiency suggest that carnitine supplementation is possibly beneficial for patients with holocarboxylase synthetase deficiency who respond incompletely to biotin therapy.

Acetylcarnitine↗