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Biomedical subjects

T Hamada

Publications and source records attributed to T Hamada.

At least 37 records · Page 2Linked to original sources
PubMed1995

Erdheim-Chester disease and slowly progressive cerebellar dysfunction.

A 59 year old woman developed pronounced thirst, increased water intake, and increased urinary output followed by slowly progressive cerebellar symptoms. Brain MRI showed abnormal hyperintensity on T2 weighted studies in the region of both dentate nuclei without atrophy of the cerebellum or the brainstem. A 99mTC diphosphonate bone scan showed bone lesions in the distal parts of both femurs as well as distal and proximal parts of both tibias. The diagnosis of Erdheim-Chester disease was made by bone biopsy. This is the first case of Erdheim-Chester disease presenting as a slowly progressive cerebellar syndrome and diabetes insipidus, and also showing high signal lesions in deep cerebellar nuclei on MRI. Skeletal surveys are indicated for patients with otherwise unexplained slowly progressive cerebellar symptoms.

Bone Diseases↗
PubMed1995

Subcorneal pustular dermatosis in a patient with hyperthyroidism.

A case of subcorneal pustular dermatosis (SPD) is reported in a 48-year-old man with a 2-year history of hyperthyroidism (Graves' disease). SPD has been reported in association with IgA monoclonal gammopathy, but to our knowledge it has not been associated with hyperthyroidism. The coexistence of hyperthyroidism and SPD suggests that immunologic factors may play a role in the pathogenesis of SPD.

Biopsy↗
PubMed1995

A case of one eye with gelatinous drop-like corneal dystrophy and the other eye with band-shaped spheroidal corneal degeneration.

The first case of gelatinous drop-like corneal dystrophy in one eye and band-shaped spheroidal corneal degeneration in the other eye was reported. She was a member of Japanese family with gelatinous drop-like corneal dystrophy. A close association between gelatinous drop-like corneal dystrophy and band-shaped spheroidal corneal degeneration was suggested.

Adult↗
PubMed1995

The effects of cross-linking agents on some properties of HEMA-based resins.

The use of 2-hydroxyethyl methacrylate (HEMA)-based polymer as a biocompatible material has been well-established. HEMA-based resins containing cross-linking agents have several potential clinical applications. It is hypothesized that the incorporation of cross-linking agent will improve the mechanical properties of HEMA-based polymers while reducing water absorption and solubility. The purpose of the work reported here was to test this hypothesis and to determine the most effective cross-linking agent. A relationship among flexural strength, modulus, water absorption and solubility, and concentration of cross-linking agent was demonstrated. Strength and modulus tend to increase as the cross-linking agent concentration is increased, up to about 50%, after which the values level out or begin to fall. Water absorption drops with increasing cross-linking agent over the whole range of concentrations. Solubility tends to show a small decrease initially (up to 40%), followed by a noticeable increase as cross-linking agent concentration is increased. The trends were similar for all cross-linking agents, although there were differences in the absolute values in all properties depending upon the type of cross-linking agent used.

Absorption↗
PubMed1995

The prozone phenomenon in secondary syphilis.

We describe a 37-year-old woman with secondary syphilis, in whom the prozone phenomenon (false-negative test in undiluted specimens) occurred. The patient had been maintained on cyclosporine and prednisolone after renal transplantation. B-cell dysfunction induced by continuous immunosuppression may lead to higher non-treponemal serological titers. Non-treponemal testing should be repeated using serum dilutions to prevent missing the diagnosis of syphilis.

Adult↗
PubMed1995

Blood flow velocity waveforms of the fetal middle cerebral artery in pregnancies complicated by diabetes mellitus.

Fetal blood flow velocity waveforms of the middle cerebral artery were measured by pulsed Doppler ultrasound in 43 pregnant women with diabetes mellitus (33 class B, 3 class C, 6 class D and 1 class R). The recordings were performed between 24 and 38 weeks of gestation. A total of 122 recordings were analyzed prior to establishing the resistance index (RI = peak systolic velocity minus diastolic velocity/peak systolic velocity). The mean maternal serum glucose was 124.3 mg/dl (range: 72.7 to 281.5 mg/dl), the mean hemoglobin A1c was 6.03% (range: 3.3 to 11.0%) and the mean fructosamine level was 255.97 mumol/L (range: 205 to 397 mumol/L). The resistance index did not differ between the fetuses of the diabetic mothers in our study population. Additionally, no significant correlation was noted between RI values and serum glucose levels (r = 0.03), hemoglobin A1c levels (r = 0.13) or fructosamine levels (r = 0.04) during the period of 26 to 34 gestational weeks. These data indicate that the RI within the fetal cerebral artery is unaffected by the maternal glycemic control when mean serum glucose levels are below 280 mg/dl.

Blood Flow Velocity↗
PubMed1995

[Combination therapy with arbekacin and fosfomycin against postoperative severe mixed-pneumonia of MRSA in primary lung cancer patients].

We experienced successful treatment of postoperative severe pneumonia of Methicillin-resistant Staphylococcus aureus (MRSA) with combination therapy of Arbekacin (ABK) and Fosfomycin (FOM) in three lung cancer patients. Case 1 was a advanced age of seventy-nine man who had had right upper lobectomy. Case 2 was a 61-year-old man who had had left lower lobectomy and extended bilateral mediastinal lymph-node dissection through the median sternotomy. And case 3 was a 59-year-old man who had suffered from pulmonary embolism after right pneumonectomy and partial resection of left atrium and superior vena cava. All cases were immuno-compromised patients and super-infected with Gram-negative rods, and Pseudomonas aeruginosa in case 1 and case 3. Clinical symptoms were improved after the start of administration of ABK and FOM inspite of ineffectiveness of prior treatment with other antibiotics. We added staggered chemotherapy of Sulbactam/Cefoperazone (SBT/CPZ) and Ceftazidime (CAZ) for case 1 and case 3 respectively. Thus, the combination therapy of ABK and FOM might be useful for severe pneumonia of MRSA in the immunocompromised patients, and the combined staggered chemotherapy of beta-lactum agents and above would be the first choice in the treatment for the case involving Pseudomonas aeruginosa.

Aged↗
PubMed1995

[A case of systemic arterial supply to the normal left basal segments with anomalous return of the left inferior pulmonary vein].

A 38-year-old man was admitted to Yatsushiro General Hospital because of an abnormal shadow on chest X-ray film. Chest X-ray film showed a tumorous shadow in the left posterior basal segment (S10). Chest CT scan showed that this shadow was consisted of torutuous vessels and was connected to the descending thoracic aorta. Angiographic examinations showed that there was no normal left basal trunk of the pulmonary artery, and revealed an anomalous arterial supply to the basal segments from the descending thoracic aorta, with an anomalous left inferior pulmonary vein. The left bronchial tree appeared normal during fibroptic bronchoscopy (confirmed by post-operative bronchography). From these findings, we determined that this patient had an systemic arterial supply to the normal basal segments. Furthermore, this patient had an anomalous left inferior pulmonary vein, which took a peculiar route to the left atrium. The left lower lobe and the anomalous systemic artery were resected. In the resected specimen, the bronchi of the left lower lobe had a normal structure and showed a normal pattern of distribution. This anomalous systemic artery had an elastic component.

Adult↗
PubMed1995

Myxoid and globular degeneration of nerves in the shoulder joint.

Characteristic degeneration of the nerves in shoulder joints was recognized in 26 of 35 capsules (74.3%) from 20 cadavers. No left or right or gender differences were found. Histologic features of the nerves were (1) thickening of the perineurium, (2) myxoid degeneration in the endoneurium, and (3) hyaline globular structures with a whorled, oligocellular appearance regarded as Renaut bodies. The results of histochemical and electron microscopic studies showed prominent degenerated collagen fibers in the globular areas. These features resembled those found in the fusiform swelling in the axillary nerve branch to the teres minor muscle, believed to be caused by chronic nerve compression. Sixty percent of the degenerated nerves occurred in the anteroinferior and posteroinferior portions of the capsule, an area that is considered to be innervated by the axillary nerve. No correlation between age and severity of these degenerative nerve changes was noted. Compression of the axillary nerve and inferior joint capsule caused by repetitive shoulder movement such as forward flexion, abduction, and external rotation of the humerus might result in this form of nerve degeneration found histologically over a lifetime without necessarily causing clinical symptoms.

Adolescent↗
PubMed1995

[A case of diffuse malignant mesothelioma diagnosed by thoracoscopic biopsy].

We report a case of diffuse malignant mesothelioma discovered by thoracoscopic examination undertaken while formulating a preoperative diagnosis. A 61-year-old male complained of coughing and sputum production, and was admitted because his chest roentgenogram indicated an abnormal shadow. Chest CT scanning demonstrated right pleural effusion and multiple nodules sited on the diaphragm. Because aspiration biopsy of such nodules was difficult, we performed a thoracoscopic examination. The thoracoscopic findings demonstrated bloody pleural effusion in the right thoracic cavity and multiple nodules on the diaphragm, parietal and pulmonary pleura. They were white and 0.5 to 2 cm in size. By excisional biopsy, these were diagnosed as epithelial-type diffuse malignant mesothelioma. We therefore performed panpleuropneumonectomy. Even though we completely resected the canal of thoracoscope and drainage tube, microscopic findings showed invasion of mesothelioma cells into this thoracoscopic canal. Although we suggest that, in preoperative diagnosis of pleural tumor, thoracoscopy is efficient to perform a pathological examination and confirm the extension of tumor, in the actual operation, we believe that the thoracoscopic canal should be resected.

Biopsy↗
PubMed1995

[A transient sinus arrest after right stellate ganglion block--assessment of autonomic function by heart rate spectral analysis].

We experienced a case of sinus arrest probably induced by right stellate ganglion block (SGB). A healthy medical student volunteered in our study of the cardiac autonomic nervous system and received the SGB. After the Holter ECG had been attached, the SGB was performed with mepivacaine 8 ml. Horner's sign was observed after about 3 minutes. A transient (15 s) sinus arrest occurred suddenly after about 6 minutes of the tilt test probably due to a vasovagal reflex, and the subject lost consciousness. From spectral analysis of the Holter ECG recording, the right SGB may be closely involved in the induction of the sinus arrest. Our present case suggests that sinus arrest may occur if a patient stands up after right SGB.

Adult↗
PubMed1995

[Infection route of MRSA to pregnant women and to newborns].

It has been reported that newborn babies are compromised hosts, and to be MRSA carriers means that the danger of occurrence of MRSA infection is high. Our department has focused on improving the hospital environment to guard against hospital infections. Infection from the hospital environment was prevented by looking for staphylococcus bacteria in the nasal cavity during pregnancy, and isolating pregnant MRSA carriers from others. Such effects as MRSA infection of the body members and organs, the newborn babies, nasal cavities of their family members, and discharging MRSA into hospital environments were investigated. 1. The rate of MRSA carriers among pregnant women was 0.8% (3.7% of pregnant women engaged in medical services, and 0.5% of pregnant women engaged in non-medical services). In the former case it was suspected that their children became MRSA carriers for some reason and they became infected through their children. In the latter case, there are two possibilities; one was that MRSA was picked up at the place of work was not removed by sterilization, so that they became carriers and the other is infection through children similarly to non-medical workers. 2. A healthy carrier was observed to be spreading MRSA in to the environment. 3. In the environment where hospital infections were fully dealt with, MRSA infection of newborn babies was always from puerperal women who were carriers. 4. The rates for both MRSA carrying in the nasal cavities of newborn babies at the time of dehospitalization and 1-month-old babies were distinctly low, when the nasal MRSA of puerperal was removed by sterilization, compared to without sterilization.(ABSTRACT TRUNCATED AT 250 WORDS)

Carrier State↗
PubMed1995

Mapping of the gene for Machado-Joseph disease within a 3.6-cM interval flanked by D14S291/D14S280 and D14S81, on the basis of studies of linkage and linkage disequilibrium in 24 Japanese families.

The gene locus of Machado-Joseph disease (MJD) has recently been mapped within a 29-cM subregion of 14q chromosome. We did a linkage study of 24 multigenerational MJD Japanese pedigrees, in an attempt to narrow the candidate region of this gene. Pairwise and multipoint linkage analysis, together with haplotype segregation analysis, led to the conclusion that the MJD gene is located at the 6.8-cM interval between D14S256 and D14S81 (Zmax = 24.78, multipoint linkage analysis). D14S291 and D14S280, located at the center of this interval, showed no obligate recombination with the MJD gene (Zmax = 5.93 for D14S291 and 9.99 for D14S280). A weak, but significant, linkage disequilibrium of MJD gene was noted with D14S81 (P < .05) but not with D14S291 or D14S280. These results suggest that a 3.6-cM interval flanked by D14S291/D14S280 and D14S81 is the most likely location of the MJD gene and that it is closest to D14S81.

Adult↗
PubMed1994

Cloning of a cDNA encoding tobacco omega-3 fatty acid desaturase.

A cDNA was isolated from a tobacco (Nicotiana tabacum cv. SR1) leaf cDNA library using, as a hybridization probe, a cDNA fragment from the gene (fad7) encoding Arabidopsis thaliana chloroplast omega-3 fatty acid (FA) desaturase. The deduced 379-amino-acid (aa) sequence has 67-71% identity to those deduced from the previously described genes encoding the omega-3 FA desaturases of A. thaliana. The absence of an N-terminal extension transit peptide in the deduced aa sequence of the cDNA clone and the accumulation pattern of the mRNA corresponding to this cDNA in leaf and root tissues indicate that the isolated cDNA encodes a tobacco microsomal omega-3 FA desaturase.

Amino Acid Sequence↗
PubMed1994

Effects of nitric oxide synthase inhibitors on N-methyl-D-aspartate-induced phase delay of circadian rhythm of neuronal activity in the rat suprachiasmatic nucleus in vitro.

Excitatory amino acid (EAA) receptors such as N-methyl-D-aspartate (NMDA) and non-NMDA receptors have been suggested to play an important role in the regulation of photic information from the retina to the suprachiasmatic nucleus (SCN). Therefore, we investigated the role of glutamate as a retinohypothalamic transmitter by analyzing the phase-resetting effects of NMDA and a non-NMDA agonist, (R,S)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA), on the circadian rhythm of SCN firing activity. Nitric oxide (NO) production is believed to be an essential intermediate in NMDA-induced cGMP production in the CNS. Thus, we examined the effects of blockers of NO production on NMDA- or AMPA-induced phase delay of SCN activity rhythm. N-nitro-L-arginine methylester (L-NAME) blocked NMDA- but not AMPA-induced phase shift, indicating the involvement of NO synthesis in NMDA-induced phase changes. L-arginine but not D-arginine caused a phase delay, and L-NAME blocked L-arginine-induced phase delay. In addition, cotreatment with NMDA and L-arginine did not have an additive effect. These results suggest that NO production itself is involved in the phase change of SCN neuron activity, and NMDA-induced phase changes are also mediated via activation of NO synthesis in this nucleus.

Amino Acid Oxidoreductases↗
PubMed1994

Protein-synthesis inhibitor blocks (R,S)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)-or substance P-induced phase shift of the circadian rhythm of neuronal activity in the rat suprachiasmatic nucleus in vitro.

The mammalian suprachiasmatic nucleus (SCN) has been identified as a circadian pacemaker. N-methyl-D-aspartate (NMDA), non-NMDA and substance P receptors have been suggested to be involved in handling of photic information in the SCN. In the Aplysia eyes, in which the circadian clocks are involved, serotonin- or cAMP-induced phase changes of the circadian rhythm were reported to be blocked by protein-synthesis inhibitors. Therefore, we investigated whether protein-synthesis inhibitor can block the non- NMDA receptor agonist (R,S)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid hydrobromide (AMPA)- or substance P (SP)-induced phase changes of SCN activity rhythm. Although application of 10 microM cycloheximide alone during the early part of the subjective night did not cause phase change, it blocked both 10 microM AMPA- and 1 microM SP-induced phase delay. The present result suggests that protein synthesis may be required in the manifestation of AMPA- and SP-induced phase change of circadian clock.

Animals↗