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Biomedical subjects

J Ito

Publications and source records attributed to J Ito.

At least 91 records · Page 5Linked to original sources
PubMed1999

Condylar bony change and craniofacial morphology in orthodontic patients with temporomandibular disorders (TMD) symptoms: a pilot study using helical computed tomography and magnetic resonance imaging.

OBJECTIVE: To investigate how condylar bony changes relate to craniofacial morphology using helical CT and MRI. DESIGN: Craniofacial morphology of orthodontic patients with condylar bony changes was compared with Japanese standard. SETTING AND SAMPLE POPULATION: The Department of Orthodontics, Niigata University School of Dentistry, Twenty-nine subjects were selected from orthodontic patients (six males and 23 females, a mean age of 18.8 +/- 6.3 years) who were diagnosed by helical CT as having condylar bony changes. EXPERIMENTAL VARIABLE: Subjects were divided into two groups: a unilateral condylar bony change group (unilateral group) (four males and nine females) and a bilateral condylar bony change group (bilateral group) (two males and 14 females). OUTCOME MEASURE: Condylar bony changes were evaluated on reconstructed coronal and sagittal CT scans. Disk positions were evaluated by MRI scans. Five linear and four angular measurements in lateral and posteroanterior cephalograms were compared with those of an age- and sex-matched 'standard population' from the Japanese standard. RESULTS: In the bilateral group, osteophyte formation and erosion were the common bony changes and were present in adult as well as juvenile subjects. In the unilateral group, flattening was the most common features and erosion was only present in subjects below 19 years. Disk displacement without reduction was seen in 90.6% of the bilateral group, and in 76.9% of the unilateral group. Retrognathic mandibles were shown in the bilateral group. All subjects exhibited a lateral shift of the menton toward the condylar bony changed side in the unilateral group. CONCLUSION: Condylar bony changes might be progressive and unstable in adults of the bilateral group as well as in juveniles of the both groups. It appears that condylar bony changes may be related to a lateral shift of the mandible and a retrognathic mandible in orthodontic patients with TMD symptoms.

Adolescent↗
PubMed1999

[Sepsis due to Salmonella Oranienburg--a case report].

A previously healthy 15-year-old female was admitted to our hospital complaining of nausea and vomiting. She did not complain of diarrhea. A physical examination revealed a lower right quadrant abdominal tenderness without rebound or spontaneous pain and a knocking pain of the costovertebral angle. A high fever, knocking pain of costovertebral angle, and urinary findings including Gram's stain, lead us to suspect a urinary tract infection, cefotiam was administered intravenously. Spiking fever with shaking chills continued for three days, and three sets of blood cultures were positive for Salmonella Oranienburg, but her urine culture was negative. Her history was taken again, revealing an intake of a processed squid product. The product was confirmed by the local public health center to be Salmonella Oranienburg. Finally food poisoning by Salmonella Oranienburg with sepsis was diagnosed. With cefotiam she became better and was discharged from the hospital on the 10th hospital day. During admission to the hospital she did not experience any diarrhea, and her stool culture was negative. Epidemics of Salmonella Oranienburg food poisoning are relatively rare in the literature. In Japan, one has arisen as a result of contamination of a processed squid product in March 1999. However, there have been no cases without so-called gastroenteritic symptoms (abdominal pain and diarrhea) who were previously healthy and developed sepsis caused by Salmonella Oranienburg, reported in Japan. Even in previously healthy patients, with an epidemic situation of non-typhoidal salmonellosis, salmonella sepsis must be ruled out. Among such cases, those who present with spiking fever and shaking chills should be given antibiotic therapy after taking appropriate cultures.

Adolescent↗
PubMed1999

Ability of nucleus cochlear implantees to recognize music.

Eight adults with cochlear implants participated in experiments to test their ability to recognize music. Some subjects showed good ability to recognize songs that were sung with instrumental accompaniment but poor ability to recognize songs played on an electronic keyboard without verbal cues, indicating that they were recognizing the songs by verbal cues rather than by musical qualities such as tones and melodic intervals. This conclusion was strengthened by the finding that subjects were barely able to distinguish between songs with the same rhythm and pitch range, and they showed poor ability to discriminate musical intervals. (The closest discrimination was 4 semitones.) Subjects had good ability to distinguish among the synthesized sounds of various musical instruments played on the electronic keyboard. We speculate that subjects could distinguish the various musical instruments in the same way they distinguish among human voices using spectrographic patterns such as formants or maxima.

Adult↗
PubMed1999

[Analysis of the cases in which Schizophyllum commune was isolated].

Infections caused by Schizophyllum commune have recently been on the increase. We analyzed cases in which this fungus was isolated from clinical samples from 1991 to 1995. Regular morphological methods were first employed in the identification of S. commune, and when necessary, mating was made with a known S. commune isolate. IgG antibodies against S. commune in the patients' serum were determined by the ELISA method. Profiles of the cases were analyzed and the English-language medical literature was reviewed. S. commune was isolated from 12 patients. Eighty three percent of the patients were female, most of which presented with allergy-related pulmonary diseases, i. e. allergic bronchopulmonary mycosis or mucoid impaction of bronchi. IgG antibodies were detectable in nine of eleven patients examined (82%). Fifty eight percent of the isolates were monokaryotic, and therefore, unidentifiable by regular morphological methods. In contrast, analysis of the English literature disclosed that sinusitis is the most common form of infection, and that hyphal invasion into the tissue was seen in 50% of reported cases. Our study shows that S. commune should be regarded as a pathogenic fungus, and is infecting humans much more frequently than previously assumed. Further investigation is warranted.

Adolescent↗
PubMed1999

[Multiple aneurysms of the PICA communicating artery: a case report].

A case with unusual type of aneurysms in the distal posterior inferior cerebellar artery (PICA) is reported here. Though only two cases with a single aneurysm of the PICA communicating artery have been reported previously, the present case is the first one with multiple aneurysms in the PICA communicating artery. A 61-year-old woman with a sudden onset of severe headache, vomiting and unconsciousness was transferred to our hospital. CT scan revealed a hematoma in the fourth, third, and lateral ventricles, and a mild subarachnoid hemorrhage at the posterior fossa. Cerebral angiogram showed the right PICA supplying the hypoplastic left PICA territory through an anastomotic vessel. Two small aneurysms were seen at the tips of hairpin curves of an anastomotic vessel, "the PICA communicating artery". Suboccipital craniotomy was performed, and the ruptured aneurysm was clipped and the unruptured one was wrapped with cotton-sheet. After the operation, her clinical recovery went well and she was discharged on foot.

Aneurysm, Ruptured↗
PubMed1999

Cicatricial fibromatosis mimics metastatic medulloblastoma.

Cicatricial fibromatoses usually occur in the anterior abdominal wall or in the extremities, but rarely in the scalp or the soft tissues of the neck. We report a case of desmoid fibromatosis that developed in a 15-year-old boy 8 months after surgery for cerebellar medulloblastoma.

Adolescent↗
PubMed1998

The hyperthermophilic bacterium Thermotoga maritima has two different classes of family C DNA polymerases: evolutionary implications.

Bacterial DNA polymerase III (family C DNA polymerase), the principal chromosomal replicative enzyme, is known to occur in at least three distinct forms which have provisionally been classified as class I ( Escherichia coli DNA pol C-type), class II ( Bacillus subtilis DNA pol C-type) and class III (cyanobacteria DNA pol C-type). We have identified two family C DNA polymerase sequences in the hyperthermophilic bacterium Thermotoga maritima. One DNA polymerase consisting of 842 amino acid residues and having a molecular weight of 97 213 belongs to class I. The other one, consisting of 1367 amino acid residues and having a molecular weight of 155 361, is a member of class II. Comparative sequence analyses suggest that the class II DNA polymerase is the principal DNA replicative enzyme of the microbe and that the class I DNA polymerase may be functionally inactive. A phylogenetic analysis using the class II enzyme indicates that T.maritima is closely related to the low G+C Gram-positive bacteria, in particular to Clostridium acetobutylicum, and mycoplasmas. These results are in conflict with 16S rRNA-based phylogenies, which placed T.maritima as one of the deepest branches of the bacterial tree.

Amino Acid Sequence↗
PubMed1998

Regeneration of the auditory pathway in adult rats by transplants of fetal brain tissue.

The ventral cochlear tract in the brain stem to pons was transected on one side in two groups of adult rats. In one group simple transection was performed, while in the other group tissue from embryos (E14-E16) was used to cover the lesion site. While rats receiving simple transection without transplantation showed no evidence of regeneration, in 30% of the rats receiving transplants of embryonic tissue the axons regrew beyond the transected site and regenerated into the denervated side and terminated at the normal targets. The present findings contradict the widely held view that the adult mammalian central auditory system cannot be restored following damage.

Animals↗
PubMed1998

Spontaneous regeneration and recovery of hearing function of the central auditory pathway in young rats.

Spontaneous regeneration of the auditory pathway after transection of the ventral cochlear tract of the brain stem to pons was examined in young rats by the anterograde tracing method with wheat germ agglutinin-conjugated horseradish peroxidase. Care was taken to cut the tract as sharply as possible to minimize traumatic injuries. About 59% of the young rats examined showed successful regeneration. Functional recovery of hearing by the regenerated fibers was confirmed by the auditory brain stem response. Thus, the present findings contradict the widely held view that the mammalian central auditory system cannot be restored following damage.

Animals↗
PubMed1998

NPY-induced feeding involves the action of a Y1-like receptor in rodents.

We have reported that the potent peptidic Y1 antagonist, 1229U91, significantly suppressed NPY-induced and spontaneous feeding [32,33]. However, information on the precise selectivity of 1229U91 for NPY receptors is lacking. The Y5 receptor has been considered a key receptor for feeding regulation. In the present study we showed that 1229U91 has high affinities for the human and rat Y1 receptors (Ki = 0.041 nM and 0.16 nM, respectively) and also a high affinity for the human Y4 receptor (Ki = 0.33 nM), whereas it shows moderate affinities for the human Y2, Y5 and rat Y5 receptors (K values of 20-170 nM). Moreover, 1229U91 potently inhibits NPY-induced [Ca2+]i increases in cells expressing human Y1 receptors. In contrast, 1229U91 is an agonist at other NPY receptors like the Y2, Y4 and Y5 receptors. Intracerebroventricular (i.c.v.)-injected 1229U91 (30 microg/head) significantly suppressed human NPY-induced feeding in SD rats, while 1229U91 only moderately inhibited bovine pancreatic polypeptide (bPP; an in vivo Y5 agonist)-induced feeding. These results indicate that the food intake evoked by NPY might be mediated by the Y1 receptor, rather than the Y5 receptor. Thus, the Y1 receptor or possibly a novel Y1-like receptor sensitive to 1229U91 may play a key role in the regulation of NPY-induced feeding.

Animals↗
PubMed1998

Studies on the cyanobacterial family C DNA polymerase.

Our studies showed that family C DNA polymerase (pol III) of the cyanobacterium Synechocystis sp. strain PCC 6803 is phylogenetically close to the Gram-negative dna E group, rather than to the Gram-positive group. However, in contrast to the dna E genes of most of the eubacteria, the cyanobacterial dna E gene has split into two genes, dna E1 and dna E2. The evolutionary origin of the split dna E gene is discussed.

Cyanobacteria↗
PubMed1998

Progressive atrophy of cerebellum and brainstem as a function of age and the size of the expanded CAG repeats in the MJD1 gene in Machado-Joseph disease.

Machado-Joseph disease (MJD) is an autosomal dominant neurodegenerative disease characterized by cerebellar ataxia associated to varying degrees with pyramidal signs, extrapyramidal signs, or peripheral amyotrophy. It is caused by unstable expansion of the CAG repeat in the MJD1 gene on chromosome 14q32.1. To determine how the neurodegenerative process in the central nervous system of patients with MJD correlates with the size of expanded CAG repeats in the MJD1 gene and other factors, we performed detailed quantitative analyses of findings of magnetic resonance imaging of the central nervous system of 21 patients with MJD of various ages and with various sizes of expanded CAG repeats. We found that atrophy of the brainstem and cerebellar vermis in MJD patients is closely correlated not only with the size of expanded CAG repeat in the MJD1 gene but also with patient age, which suggests that the neurodegenerative process in MJD is regulated by the size of expanded CAG repeats as well as by the patient age.

Adult↗
PubMed1998

MRI of enlarged endolymphatic sacs in the large vestibular aqueduct syndrome.

We studied ten inner ears of five patients with a bilateral large vestibular aqueduct syndrome, using CT and MRI. Although the large vestibular aqueduct varied in size, a markedly dilated endolymphatic sac extending to the sigmoid sinus was demonstrated bilaterally on MRI in all patients. The cause of hearing loss in this syndrome is unclear. However, it is suggested that reflux of the protein-rich, hyperosmolar endolymph from the enlarged endolymphatic sac (EES) into the cochlea through a widely patent endolymphatic duct may damage the neuroepithelium. CT density and spin-echo MRI signal intensity of the endolymph in EES were markedly higher than those of CSF in eight inner ears of four patients. Increased density and high signal may indicate protein-rich, hyperosmolar endolymph. In some patients with sensorineural hearing loss and EES, the vestibular aqueduct may not appear dilated on CT. MRI is therefore necessary for correct diagnosis of this syndrome, which should more correctly be termed "large endolymphatic duct and sac syndrome". Prominent EES may predict poor prognosis in this syndrome.

Adolescent↗
PubMed1998

Oncocytic lipoadenoma of the submandibular gland.

We report a case of oncocytic lipoadenoma of the submandibular gland, previously unrecognized benign tumor of the salivary gland. The patient was a 66-year-old Japanese woman with a left submandibular mass, measuring 11 x 7.5 x 5 cm. Microscopically, the mass was completely surrounded by a thin fibrous connective tissue capsule, and was composed of an intimate admixture of mature fat cells and oncocytes. There have been no English reports of such a neoplasm in the salivary gland with the exception of one recent case report of lipoadenoma of the parotid gland without oncocytic features. We propose the diagnostic term "oncocytic lipoadenoma" for this benign tumor.

Adenoma↗
PubMed1998

Axonal regeneration with functional restoration in the vestibulospinal tract in young rats.

The present study examined regeneration and restoration of function of the mammalian central vestibular system in the infant rat. The lateral vestibulospinal tract (LVST) of rats was completely transected unilaterally by a ventral approach. After a postoperative interval of one day to three months, the LVST was examined by anterograde transport of wheat-germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) and retrograde transport of fluorescent dye. Twelve of the 22 LVST-transected rats showed successful regeneration. The regenerated fibers formed a compact fiber bundle, which sent terminals to their normal targets. The contribution of the regenerated fibers to functional recovery was estimated by analyzing the locomotor capacity of the transected rats. The locomotor movements were measured on the surface of a digitizer table by attaching a miniature resonance coil to the abdomen of the rats. Rats which shows normal locomotor movements represented a marked regeneration of LVST fibers. In contrast, rats with poorly-controlled locomotor movements showed unsuccessful regeneration. These results suggest that, contrary to previous thought, regeneration and functional restoration of the central vestibular system in young rats does occur.

Amidines↗
PubMed1998

Postnatal changes in locomotor movements after labyrinthectomy in rats.

The influence of unilateral or bilateral labyrinthectomy on the postnatal development of locomotor movements was studied in newborn rats. Locomotor movements of the rats were measured on the surface of a digitizer table by attaching a miniature resonance coil to the abdomen of the rat. Labyrinthectomy was performed in rats on postnatal day (PND) 11. From PND 10 to PND 14, the total distance and mean velocity of locomotor movements were significantly lower in the labyrinthectomized rats than in the control rats. From PND 17 to PND 20, the total distance and mean velocity of the locomotor movements of the unilateral labyrinthectomized rats gradually recovered to an almost normal level. However, those of the bilateral labyrinthectomized rats remained at insufficient levels even at PND 20.

Animals↗
PubMed1998

Influence of the multichannel cochlear implant on vestibular function.

Vestibular function was examined in 55 adult patients who underwent cochlear implant surgery. The percentages of the patients with normal results on an optokinetic nystagmus test and eye-tracking test before surgery were 85% and 82%, respectively. A caloric stimulation test was performed before surgery, and 67% of patients showed hypofunction or afunction. This same test was performed approximately 1 month after surgery, and 38% of patients showed functional deterioration. After surgery 47% of the patients reported some kind of subjective dizziness. The characteristics of dizziness were divided into three types: early, prolonged, and delayed. Fifty-eight percent of the patients had early type, 34% had prolonged type, and 8% had the delayed type. Eighteen percent of the patients felt dizziness when they used the implant device, indicating that electrical current spread from the implant device to the vestibular nerve. The other 82% of the patients did not report any relationship between the use of their cochlear implants and dizziness.

Adult↗