Biomedical subjects

T Hamada

Publications and source records attributed to T Hamada.

At least 415 records · Page 23Linked to original sources

PubMed1993

Myoclonus and seizures in a patient with parkinsonism: induction by levodopa and its confirmation on SEPs.

A 68-year-old woman with parkinsonism showed cortical myoclonus and seizures under antiparkinsonian medication. Myoclonus was induced and enhanced by L-dopa, developing into generalized seizures. EEG was abnormal and somatosensory-evoked potentials (SEPs) showed giant SEPs, transcortical reflex (C reflex) and jerk locked potentials. Myoclonus and seizures disappeared after discontinuation of L-dopa and the introduction of valproate sodium (VPA). We described the occurrence of L-dopa-induced myoclonus and seizures in a case of parkinsonism with its SEPs findings.

Aged↗

PubMed1993

Color and pulsed Doppler ultrasonography of reversed umbilical blood flow in an acardiac twin.

Prenatal diagnosis of an acardiac twin pregnancy was performed. At 30 gestational weeks, pulsed color Doppler ultrasound revealed polyhydramnios, reversed-pulsatile blood flow in the umbilical artery and vein of the acardiac twin, and artery-artery anastomosis on the placental surface. The total cardiac dimension, maximum blood flow velocity of the ascending aorta and the pulmonary artery in the alive twin were in the normal range.

Adult↗

PubMed1993

Presynaptic alpha 2 adrenoceptors inhibit glutamate release from rat spinal cord synaptosomes.

The presynaptic regulation of amino acid release from nerve terminals was investigated using synaptosomes prepared from the rat spinal cord. The basal releases of endogenous glutamate (Glu), aspartate (Asp), and gamma-amino-butyric acid (GABA) were 34.6, 21.5, and 10.0 pmol/min/mg of protein, respectively. Exposure to a depolarizing concentration of KCl (30 mM) evoked 2.7-, 1.5-, and 2.9-fold increases in Glu, Asp, and GABA release, respectively. Clonidine reduced the K(+)-evoked overflow of Glu to 56% of the control overflow with a potency (IC50) of 17 nM, but it did not affect K(+)-evoked overflow of Asp, GABA, and their basal releases. Similarly, noradrenaline inhibited the K(+)-evoked overflow of Glu, although phenylephrine and isoproterenol showed no effect. The inhibitory effect of clonidine was counteracted by alpha 2-adrenoceptor antagonists, rauwolscine, yohimbine, and idazoxan, regardless of the imidazoline structures. Because Glu is considered a neurotransmitter of primary afferents that transmit both nociceptive and nonnociceptive stimuli in the spinal cord, these data suggest that part of Glu release may be regulated by the noradrenergic system through alpha 2 adrenoceptors localized on the primary afferent terminals.

Adrenergic alpha-Agonists↗

PubMed1993

Nevus depigmentosus systematicus with partial yellow scalp hair due to selective suppression of eumelanogenesis.

We report a Japanese patient with congenital hypomelanosis with a segmental pattern on the left abdomen, whorl-like pattern on the back; mosaic pattern on the chest, right abdomen, and proximal extremities; and with yellow hair on a portion of the scalp. Chemical analysis of the yellow hair revealed decreased eumelanin content, whereas the pheomelanin content was normal.

Hair Color↗

PubMed1993

Cerebrospinal fluid IgG profiles and multiple sclerosis in Japan.

We analyzed the cerebrospinal fluid (CSF) IgG profiles of 46 Japanese patients with relapsing and remitting types of multiple sclerosis (MS). There were 12, 13 and 21 patients, with inactive, active and both clinical conditions, respectively. The values for IgG, IgG/Alb ratio, IgG index and IgG synthesis rate were significantly higher during active than during inactive stages, but the patients with high values for these IgG profiles during active stages tend to also have high values during inactive stages. None of 33 (0%) and 2 of 34 patients (5.9%) exhibited abnormal IgG levels, 3 (9.1%) and 8 (23.5%) an abnormal IgG/Alb ratio, 9 (27.3%) and 18 (52.9%) an abnormal IgG index, and 5 (15.2%) and 14 (41.2%) an abnormal IgG synthesis rate, during inactive and active stages, respectively. Some of HLA antigen frequencies were significantly different between the patients with and without abnormal CNS IgG profiles. Increased CSF IgG was of lesser diagnostic value for MS in Japan, and seemed to be a function of immunogenetics rather than clinical activity.

Female↗

PubMed1993

Anticardiolipin antibodies in Japanese patients with multiple sclerosis.

We evaluated circulating anticardiolipin antibodies (aCL) in 38 Japanese patients who fulfilled the criteria of clinically definite multiple sclerosis (MS), using a newly developed EIA system with aCL-cofactor. Two of 38 patients (5.3%) had a aCL-cofactor-dependent positive serology, and differences compared with findings in controls were statistically significant. The 2 aCL-positive patients had similar clinical features with acute transverse myelopathy (ATM), optic neuropathy (OPN), normal cranial MRI and negative oligoclonal IgG bands (OCBs) in the cerebrospinal fluid (CSF). Among the 38 patients, 3 had ATM, OPN, normal cranial MRI and negative OCBs, hence, in a significant number of the patients (2/3; 67%) with these distinctive features, serology for aCL was positive. Therefore, they may have another condition associated with aCL, masquerading as MS. Serological testing for aCL with aCL-cofactor is recommended for the patients with clinical diagnosis of MS, especially for those showing OPN and ATM during the clinical course, and in Asian peoples where the incidence of ATM and OPN is relatively high among the patients with diagnosis of MS.

Adolescent↗

PubMed1993

Contact allergies to topical corticosteroids.

The patient, a 34-year-old Japanese woman who noticed worsening of her rash after using topical corticosteroid preparations on her neck, was patch tested for both commercial preparations and corticosteroids themselves. The patch test results revealed that she had a contact allergy to gold, oxytetracycline, and 2 types of corticosteroid (acetonides and esters) in 7 compounds (betamethasone valerate and dipropionate, hydrocortisone butyrate and hydrocortisone butyrate propionate, amcinonide, budesonide, and fluocinonide).

Administration, Cutaneous↗

PubMed1993

Germ tube formation and proteinase activity of Candida albicans in relation to virulence for mice.

Standard strains and clinically isolated strains of Candida albicans were tested for their virulence for mice. Lethal effects of yeast forms of clinical isolates were stronger than those of germ tube-forming cells in all except one strain. The germ tube of C. albicans JCM1542 killed mice earlier than the yeast form. Proteinase activity of the clinically isolated strains from patients with dental caries and xerostomia was negatively correlated with median survival time (MST) of mice which were injected with 1 x 10(6) yeast form cells. The yeast forms of the standard strains had a weak lethal effect on mice compared with their proteinase activity and the yeast forms of the clinical isolates from patients with acute pseudomembranous candidiasis and denture stomatitis had a highly lethal effect with relatively low proteinase activity. These results indicate that the virulence of C. albicans in partially due to proteinase activity.

Animals↗

PubMed1993

Effect of somatostatin on circadian rhythms of firing and 2-deoxyglucose uptake in rat suprachiasmatic slices.

In mammals, the suprachiasmatic nucleus (SCN) of the hypothalamus appears to act as a circadian clock. The SCN vasoactive intestinal polypeptide-like immunoreactive neurons, which may act to mediate photic information in the SCN, receive input from neurons immunoreactive for somatostatin (SST). Therefore we investigated the role of SST as a transmitter for entrainment by analyzing the phase-resetting effect of SST on the circadian rhythm of SCN firing activity. Perfusion of SST increased 2-deoxyglucose uptake at circadian time (CT) 18, but not at CT6. A 1-h or 15-min treatment with SST produced phase delays when it was administered at CT13-14 and phase advances at CT22-23. Thus SST-induced phase changes are similar to those for light pulses to animals under constant darkness. The present findings suggest that SST is a transmitter for mediating information of entrainment to circadian clocks within the SCN.

Animals↗

PubMed1993

Cell death and regeneration of renal proximal tubular cells in rats with subchronic cadmium intoxication.

Male Sprague-Dawley rats were injected subcutaneously with 0.6 mg cadmium (Cd)/kg/day for 8 wk. The subsequent changes in renal proximal tubules were studied histologically, histochemically, and ultrastructurally. The urinary and tissue Cd concentrations were determined by atomic absorption spectrophotometry. After 4 wk of exposure, apoptosis was observed predominantly in segment S3 along with epithelial regeneration in the affected tubules, and these changes gradually became more pronounced as the experimental period was prolonged. The apoptotic cells were shed into the lumen and were found to contain a large quantity of Cd. Apoptotic cells were counted in paraffin sections after various periods of exposure to Cd. Nuclear bromodeoxyuridine uptake, mitotic count, and nuclear density were used as indicators of tubular regeneration. A correlation was found between the numerical increase of apoptotic cells and the rate of urinary Cd excretion, and the rate of increase in the tissue Cd concentration had a tendency to reduce after 4 wk as the rate of urinary Cd increased. These observations suggest that apoptosis might be helpful for the efficient excretion of Cd into urine. Progressive increases in the preceding indicators of regeneration were observed. From our results, it appears that Cd-induced tubular damage, i.e., cell deletion due to apoptosis, is reversible as a result of marked epithelial regeneration. On the basis of these histological changes, the critical concentration of Cd required to produce renal tubular damage was estimated to be 600 micrograms/g dry tissue.

Animals↗

PubMed1993

Frontal intermittent delta activity in schizophrenic patients receiving antipsychotic drugs.

FIRDA was found in 14 EEGs recorded from 338 schizophrenic patients receiving antipsychotic drugs, although they showed no FIRDA in the baseline EEG. The daily dose of antipsychotic drugs when FIRDA was found was larger than when FIRDA disappeared. FIRDA was assumed to be induced by relatively high doses of antipsychotic drugs. Thus, the effect of antipsychotic drugs should be added to the list of differential diagnoses associated with FIRDA. FIRDA did not correlate with the baseline psychopathology of schizophrenic patients. Patients without FIRDA tended to respond poorly to antipsychotic drugs in terms of negative symptoms. Improvement of positive symptoms in FIRDA patients was not as remarkable as in patients without FIRDA.

Adolescent↗

PubMed1993

Glucagon and ALS.

Explore the source record for details and available documents.

Amyotrophic Lateral Sclerosis↗

PubMed1993

A study of cis-diamminedichloroplatinum(II) suppositories for the treatment of rabbit uterine endometrial carcinoma.

cis-Diamminedichloroplatinum (II) (cisplatin: CDDP) suppositories containing NaCl at different concentrations were prepared as a local chemotherapeutic agent for the treatment of uterine endometrial carcinoma and were administered to rabbits implanted with uterine VX2 tumor. The intrauterine CDDP histological level, as well as the antitumor effects and side effects of the suppositories to the liver and kidney were studied. The results showed high intrauterine tissue CDDP level in all suppository administrations. In particular, the NaCl-added suppositories enhanced the intrauterine CDDP level. As for antitumor effects, while the tumor growth rate of the NaCl-added suppository group was likely to be suppressed, the suppositories could not suppress tumor growth completely. The plasma platinum (Pt) level was 1.5 micrograms/ml or less and that of the liver and kidney was as low as 0.31 to 0.48 micrograms/g. No difference in levels depending on NaCl concentration was observed, nor was any abnormality found in the biochemical analysis including glutamate oxaloacetate transaminase (GOT) and blood urea nitrogen (BUN). Histopathological study revealed the degeneration of tumor cells in the NaCl-added suppository group. Minimal congestion and hemorrhage were observed in the endometria, possibly resulting from CDDP. By adding NaCl to CDDP suppositories, the uterine CDDP level and antitumor effects increased while no serious renal dysfunction was noted. Therefore, we conclude that NaCl-added CDDP suppositories are a useful local chemotherapy for endometrial carcinoma.

Animals↗

PubMed1993

Fatal acute hepatitis B virus infection while receiving immunosuppressants after renal transplantation.

A 47-year-old man with acute hepatitis B virus (HBV) infection who had been receiving immunosuppressants after renal transplantation developed progressive liver failure. During the clinical course (approximately 7 months), anti-HBc IgM antibody and HBV-DNA polymerase levels remained high, but the serum alanine aminotransferase (ALT) level was consistently less than 150 K.U. Histopathologic examination of the liver showed submassive hepatic necrosis without significant inflammation accompanied by marked fibrosis. Most hepatocytes showed strong nuclear expression of HBc antigen by immunohistochemical staining and electron microscopy revealed numerous intranuclear core-like particles. Hepatitis B virus infection in immunosuppressed individuals occasionally insidiously progresses, resulting in liver failure. The clinical course of such patients thus merits close scrutiny.

Acute Disease↗

PubMed1993

Laparoscopic treatment of ectopic pregnancies--reports of two cases.

Two cases with ectopic pregnancy were successfully treated by laparoscopic injection of methotrexate (MTX). Case 1: A 29 year-old housewife was laparoscopically treated with a 15 mg MTX injection to the left Fallopian tube. After the laparoscopy, the human chorionic gonadotropin (HCG) was reduced to the normal range. Case 2: A 34 year-old housewife was also laparoscopically treated with a 35 mg MTX injection to the right Fallopian tube. After the laparoscopy, the HCG was quickly reduced to the normal range. The endoscopic approach can be used as the surgical treatment of choice for ectopic pregnancies.

Adult↗

PubMed1993

[Morphological investigation of external sphincter muscle of the male posterior urethra].

For investigation of function of the male posterior urethra, morphological study was performed in terms of the muscle architecture including sphincter muscle of the posterior urethra. The muscle localization was demonstrated by microdissection in eight male cadavers. Histological examination was also employed with HE staining and immunohistochemical method to detect the nature of these muscles. At the dorsal side, the muscle fibers of the deep trigone were located from the inter-ureteral ridge beyond the bladder neck to the vermontanum surrounding the posterior urethra. They were regarded as the internal urethral sphincter muscles. At the ventral side, the muscle fibers were also found just outside the ventral prostate running from the base to the apex of the prostate. Then, they were circularly located around the membranous urethra. These saddle shaped muscles were proved to be striated muscle by the immunohistochemical examination using anti-Desmin and anti-Myoglobin antibody. Therefore, the external urethral sphincter muscle would consist of the pelvic floor muscles and the urethral sphincter muscles.

Aged↗

PubMed1993

[Studies on the medicinal plant in the "Sambutsu-cho" of Higo Province possessed by the Kumamoto Clas (I): on the medicinal trees].

The Sambutsu-cho, a list of the natural products of the Kumamoto clan in Higo Province was dedicated to the Tokugawa shogunate in 1735. This book had many names of the plants, animals and minerals. In the plant kingdom, there were many names, wild and cultivated, of cereals, vegetables, fruits, trees, bamboos, herbs, seaweeds and mushrooms. In this report, I studied the species of the trees which were listed up by the Chinese names, Japanese standard and local names. I identified them and found 109 species. Among them, 67 species were medicinal plants. For example, the names of the crude drugs such as Gardeniae fructus, forsythiae fructus and phellodendri radix were found. The ratio of the medicinal plants was 61%.

Botany↗

PubMed1993

[Studies on the medicinal plant in the "Sambutsu-cho" of Higo Province possessed by the Kumamoto clan (II): on the medicina herbs].

In the previous report, I studied the medicinal trees contained in the Sambutsu-cho of the Kumamoto clan in Higo Province. In this report, I studied the medicinal herbs contained in the same book. There were 439 names in the herbal part. I identified 214 species and found 129 species as the medicinal plants. The ratio of the medicinal plants was 60%. the famous medicinal plants were as follows: Atractilodes japonica, platycodon grandiflorum, prunella vulgaris var. lilacina, pharbitis nil, cnidium officinale, angelica acutiloba, bplerum falcatum, pueraria lobata, sophora flavescens, sinomenium acutum, akebia quinata, paeonia lactiflora, paeonia suffruticosa, achyranthes fauriei, houttuynia cordata, ophiopogon japonica, pinellia ternata and cyperus rotundus.

Botany↗