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Biomedical subjects

S Nonaka

Publications and source records attributed to S Nonaka.

At least 91 records · Page 5Linked to original sources
PubMed1994

Brain areas essential or non-essential for emesis.

This study was undertaken to better delineate those brain regions that are either essential or non-essential for vomiting. Fictive vomiting, identified by a characteristic pattern of respiratory nerve discharge, was induced by a combination of emetic drugs and electrical stimulation of abdominal vagal afferents in decerebrate, paralyzed cats. Regions non-essential for coordinating vomiting included the entire cerebellum, structures rostral to the medullary retrofacial nucleus, and spinal cord. Fictive coughing was also elicited following cerebellar removal but was not studied after other procedures. The respiratory-related components of fictive vomiting were abolished by large lesions or kainic acid injections in the lateral medulla at the level of the retrofacial nucleus, where respiratory pre-motor and motor neurons are known to exist. Electrical stimulation of this region of the brainstem failed to evoke vomiting. The results of the present study are consistent with our previous electrical stimulation [Brain Res., 270 (1983) 154-158] and c-fos [J. Neurosci., 14 (1994) 871-888] studies and the hypothesis that emesis is coordinated not by a unique, well-defined 'vomiting center' but rather by a distributed control system located in the medulla between the levels of the obex and the retrofacial nucleus.

Abdominal Muscles↗
PubMed1994

Plasticity of emesis to a 5-HT3 agonist: effect of order of visceral nerve cuts.

Serotonin type 3 receptors are critical for vomiting induced by radiation and cancer chemotherapy. To investigate the mechanisms involved, we analyzed the effects of abdominal visceral denervation using cats. Thresholds for vomiting induced by the serotonin-3 receptor agonist phenylbiguanide varied depending on the order of chronic nerve transections. Lower thoracic vagotomy, splanchnicectomy, and their sequential combination increased thresholds. However, when splanchnicectomy, which causes a large increase in threshold, was followed 14-51 days later by vagotomy, thresholds dropped by an average of 40%. These results demonstrate plasticity in, and potential for modulation of, the emetic reflex.

Animals↗
PubMed1994

Coexistence of ochronosis and rheumatoid arthritis.

We describe a 64-year-old female patient with ochronosis and rheumatoid arthritis. Magnetic resonance imaging of the spinal column disclosed the destruction of vertebral disks, and a bony bridging in Th12 to L2. In addition, we observed joint space narrowing in the wrists as well as among the carpal bones, positive rheumatoid factor and the presence of rheumatoid nodules, in which the histological findings were compatible with those of rheumatoid arthritis. The co-existence of these two diseases has not yet been previously reported. Pre-existing ochronotic arthropathy might have masked the manifestation of rheumatoid arthritis and made the diagnosis of rheumatoid arthritis rather difficult.

Arthritis, Rheumatoid↗
PubMed1994

Additive two DMARD therapy of the patients with rheumatoid arthritis.

From the beginning of 1987 to the end of 1989, 72 rheumatoid arthritis patients (RA) whose disease could not be controlled by a single disease modifying antirheumatic drug (DMARD) were selected for the trial treatment. They continued the DMARD treatment used initially at its regular dose, and then started another DMARD regimen at 1/3 to 1/2 of the regular dose as an additive DMARD treatment, which we have designated as Additive Two DMARD Therapy (ATDT). The patients were followed until the end of 1992. In the 3 months of ATDT, the effectiveness of ATDT was obtained in 42 (58.3%) patients who showed more than a 30% decrease in the initial Lansbury's activity index (AI). The rate of side effects at 3 months were 5.6%. Tiopronin, bucillamine or salazopirine added to gold sodium thiomalate or tiopronin were suggested as the recommended DMARD combinations for ATDT. The suppressive effects on AI, ESR, CRP and rheumatoid factor continued for as long as 18 to 24 months. The mean period of ATDT was 21.7 months and that at which ATDT proved useful was 31.9 months. A discontinuation of the first DMARD treatment without any following disease aggravation was obtained in 10 of 15 patients whose disease activity had been sufficiently suppressed for longer than a year. In conclusion, ATDT was suggested to be a useful way of treating RA patients whose disease activity could not be controlled by a single DMARD treatment, as well as a way of evaluating the next DMARD while the ongoing DMARD was observed to gradually lose its initial drug effect.

Adult↗
PubMed1994

Methotrexate for steroid-resistant systemic lupus erythematosus.

We here report two patients with steroid-resistant systemic lupus erythematosus (SLE) who were successfully treated with methotrexate (MTX). In both cases, a steroid resistant high fever, associated with mild myositis and pancytopenia were the main common findings, and all these symptoms were alleviated within a few days either by 7.5 mg or 5 mg MTX per week. The number of CD4+ cells increased along with the clinical improvement, whereas the number of CD20+ cells and HLA-DR expressing cells also decreased. Taking into account the side effects of high dose corticosteroids and cyclophosphamides, treatment with a weekly low dose of MTX is known to contribute to an improvement in the long-term prognosis for patients with refractory SLE.

Adult↗
PubMed1994

Coinfection of hepatitis C virus in patients with chronic hepatitis B infection.

Enzyme-linked immunosorbent assays for detecting antibodies against hepatitis C virus and the polymerase chain reaction were tested in 82 chronic hepatitis B surface antigen carriers for their accuracy in diagnosing patients coinfected with hepatitis B and C viruses. To clarify the role of each virus in chronic hepatitis, serologic assays against hepatitis B virus were also tested. Thirteen (14.9%), 14 (17.1%) and 15 (18.3%) patients were anti-HCV positive using C100 (HCV1), JCC, and a second generation test (HCV2), respectively. HCV RNA was detected by polymerase chain reaction in 9 of 18 anti-HCV-positive cases. Although HCV1 assays were not sufficient, either the JCC or HCV2 assay detected all polymerase chain reaction-positive cases. Fifteen of 18 specimens that were positive in at least one of the three ELISA were seronegative for the hepatitis B e antigen. As judged by HBV DNA polymerase activity, titers of hepatitis B surface antigen and immunoglobulin A antibody against hepatitis B core antigen (IgA anti-HBc), activity of hepatitis B virus replication and immune response against hepatitis B virus in patients with coinfection was decreased to the level of hepatitis B virus asymptomatic carriers. These results show that hepatitis C virus appears to be the primary cause of active hepatitis in most patients with hepatitis B and hepatitis C virus coinfection.

Adolescent↗
PubMed1994

Histopathological and electron microscopical features of skin lesions in a patient with bartonellosis (verruga peruana).

Chronic verruga nodules taken from a patient with Bartonellosis (verruga peruana) were studied. Histologically, specimens of all the verruga nodules had features consistent with granulomatous lesions with extensive infiltration of various types of cells along with the proliferation of capillaries. The sections were predominantly infiltrated with neutrophils and endothelial cells; histiocytes, plasma cells, lymphocytes and mast cells were also visible to some extent. The blood vessels were dilated, and many rounded and swollen endothelial cells were located peripherally; a huge number of neutrophils invaded the vessels. Electron microscopically, large number of organisms were seen in different stages of the life cycle in the stroma. Furthermore, organisms were regularly seen either in close contact or existing inside the cytoplasm of neutrophils, suggesting the phagocytic role of these cells. No organism was found inside any endothelial cells or histiocytes.

Bartonella Infections↗
PubMed1994

A case of acquired lymphangioma due to a suspected old filariasis and a review of literature.

A 65-year-old man presented in 1992 with multiple papular lesions on the scrotum and foreskin. His medical history revealed that, at the age of 25, he was diagnosed as having filariasis and treated conservatively at a hospital in Hawaii. The histologic study of the scrotal skin showed large, dilated vascular spaces in the upper dermis lined with a single layer of endothelial cells that were negative for Factor 8-related antigen. The diagnosis was acquired lymphangioma due to a suspected old filariasis infestation, although serologic tests for filarial antibodies were negative. The paper also presents a review of the literature of acquired lymphangioma in Japan with a brief discussion of etiology and nomenclature.

Adult↗
PubMed1994

Relationship between porphyria cutanea tarda (PCT) and viral hepatitis.

Recent reports have revealed the high prevalence of serological markers of viral hepatitis in porphyria cutanea tarda (PCT). We present two cases of PCT associated with hepatitis C and discuss the relationship between PCT and viral hepatitis. Case 1: A 50-year-old Japanese male noticed blisters, erosions, and fragility on sun-exposed areas of his skin in November of 1990. He had no history of excessive alcohol intake. He had been taking analgesics for eighteen years. Case 2: A 64-year-old Japanese male was referred in October of 1989 because of pigmentation on sun-exposed areas of his skin. He had been drinking alcohol excessively for 43 years. The hepatitis C virus (HCV) antibody was present in each case. Tests for the HCV antibody and hepatitis B serological markers were run in 5 other patients. HCV antibody was present in 3 of them. The two cases negative for the HCV antibody exhibited the hepatitis B antibody. We speculated that viral hepatitis infection may play an important role in precipitating PCT in cases with a history of a long term excessive intake of alcohol or chemicals.

Hepatitis C↗
PubMed1994

The effects of sunscreens on UVB erythema and Langerhans cell depression.

Langerhans cells (LCs) are epidermal antigen-presenting cells capable of initiating a specific T lymphocyte-mediated immune response. It is a well known fact that ultraviolet light B (UVB) suppresses LC number and function. In this study, we confirmed that the sunscreens CITY BLOCK, and TOTAL SUN SHIELD 28 (Clinique Laboratories Tokyo, Japan) protected the epidermis against the depletion of LC number. We also investigated whether or not sunscreens could provide LC protection from ultraviolet ray (UVR) damage other than the prevention of the decrease in the total number of cells. Our data showed that the LC population was depressed after irradiation by 100 mJ/cm2 or 10 mJ/cm2 of UVB, but recovered to within normal levels after 16 days. Both sunscreens provided protection against erythema and LC depression due to UVB irradiation. However, despite the fact that these sunscreens had completely suppressed UVB erythema, shrinkage of LC dendrites was seen. Apparently, sunscreens prevent UVB erythema, but do not protect against functional changes in LC due to UVB. Recently, it has been reported that sunscreens are less effective in protecting against systemic immunosuppression that against inflammation. The shrinkage of LC dendrites despite sunscreen application may help explain this discrepancy.

Animals↗
PubMed1994

A case of double cancer: a squamous cell carcinoma arising from a long pierced site on the left earlobe and a solid tubular carcinoma of the left breast.

A 43-year-old woman presented with a well differentiated squamous cell carcinoma of the left earlobe where a small hole for pierced type earrings had been made about 20 years earlier. A year after the removal of the tumor, a metastasis of a moderately differentiated squamous cell carcinoma to the left cervical lymph nodes was detected. A month later, a solid tubular carcinoma of the left breast was found. A modified radical neck dissection and a quadrantectomy with an axillary lymph node dissection were performed. A total of 5 courses of peplomycine-mitomycine combinated therapy with 26 Gy of radiotherapy was administered for the cervical lesion. A month of postoperative chemotherapy with tegafur-uracil and medroxyprogesterone acetate and a total of 56 Gy of radiotherapy to the mammary lesion were added. She has been well without recurrence for about a year after the operations. This case is not only a rare double cancer, a combination of a squamous cell carcinoma and a solid tubular carcinoma, but may also be the first case of a squamous cell carcinoma arising at a long pierced site on an earlobe for pierced type earrings.

Adenocarcinoma↗
PubMed1994

Trilineage response to rhG-CSF with subsequent clonal hematopoiesis in a patient with severe bone marrow aplasia.

We treated a patient with severe aplastic anemia with long-term administration of recombinant human granulocyte-colony stimulating factor (rhG-CSF). When a trilineage response of hematopoiesis was obtained after the first treatment, a chromosomal change [45XX, -7] was observed in 20 of the 20 metaphases examined. Later, we were able to show a monoclonal X inactivation pattern in the phosphoglycerate kinase (PGK) gene in the peripheral blood polymorphonuclear leukocytes and mononuclear cells, indicating the presence of clonal hematopoiesis regardless of the disappearance of the karyotype abnormality. We suggest that it is important to pay close attention to the appearance of clonal hematopoiesis during the administration of G-CSF to patients with idiopathic severe bone marrow aplasia.

Adult↗
PubMed1994

[Nasal decongestion evaluated by acoustic rhinometry].

Acoustic rhinometry measures the cross-sectional area of the nasal cavity based on changes in acoustic impedance. The volume of the nasal cavity can be calculated by mathematical integration of the cross-sectional areas. One of the advantages of this procedure is that repeated measurements can be quickly performed non-invasively. In this study, we analyzed the mechanisms of nasal mucosal decongestion after applying vasoactive agents. The experiments were performed in normal adult volunteers (17 males, 3 females) who gave their informed consent to participate in this study. Three vasoactive agents (0.1% epinephrine, 0.5% phenylephrine hydrochloride, 0.5% oxymetazoline hydrochloride), two alpha-receptor antagonists (0.2% phenoxybenzamine, 0.4% yohimbine) and a local anesthetic (4% lidocaine) were used. In order to apply the agents precisely and safely, we attached a 6mm diameter disc moistened with 0.1 ml of solution to the anterior portion of the inferior turbinate unilaterally for fifty seconds. After removing the disc, acoustic measurements were performed for an hour. To analyze data we divided the nasal cavity into three portions, i.e., anterior, middle and posterior. Volume changes in each portion are expressed as percentages. Immediately after applying phenylephrine and oxymetazoline, ipsilateral volume in the anterior portion began to increase, and then extended posteriorly. The level of decongestion remained unchanged for an hour. Contralateral volume decreased in all portions. When epinephrine was applied, mucosal decongestion occurred first followed by congestion in all portions of the ipsilateral side after 20 minutes. Mucosal congestion occurred in all portions of the contralateral side. After applying phenoxybenzamine or yohimbine for ten minutes, we administered vasoactive agents topically. Pretreatment with alpha-1 antagonist almost totally suppressed the mucosal decongestion caused by phenylephrine and oxymetazoline. Contralateral congestion was decreased by antagonizing the suppression of ipsilateral decongestion. After application of lidocaine for ten minutes, phenylephrine still caused ipsilateral decongestion only in the anterior portion, but decongestion of the middle and posterior portion and congestion on the contralateral side totally disappeared. These findings suggest the following conclusions: 1) decongestion evoked by adrenergic agents is probably caused by direct activation of alpha-1 receptors, 2) decongestion of the middle and posterior portions is evoked by drug particles conveyed by ciliary movement, and 3) the contralateral response is probably related to the activation of sensory nerves on the ipsilateral side.

Acoustics↗
PubMed1994

[The comparison of clinical features between early rheumatoid arthritis and established rheumatoid arthritis].

Clinical features between 69 early RA patients (within a year duration) and 79 established RA patients (more than 3 years duration) were compared retrospectively. There were no significant differences about frequencies of morning stiffness (68.2% vs 54.4%) and rheumatoid nodules (20.2% vs 15.2%) between early RA and established RA. There were also no significant differences between two groups about elevation of ESR (92.8% vs 97.4%), positivity of CRP (97.1% vs 94.9%) and rheumatoid factor (RF) (82.6% vs 93.7%), and Lansbury activity index (AI) (mean 68.8% vs 78.8%). After hospitalization and treatment, all clinical indices (ESR, CRP, RF, AI) improved significantly in both groups. There, however, were clinically more "marked improvement" (39.1% vs 16.4%) and "remission" (8.7% vs none) in early RA group. We conclude that by hospitalization and treatment, clinical improvement can be expected in both early and established RA, but to secure satisfactory improvement, early detection and intervention of RA would be recommended.

Adult↗
PubMed1993

The primary structure of rat brain (cytoplasmic) dynein heavy chain, a cytoplasmic motor enzyme.

Overlapping cDNA clones encoding the heavy chain of rat brain cytoplasmic dynein have been isolated. The isolated cDNA clones contain an open reading frame of 13,932 bp encoding 4644 aa (M(r), 532,213). The deduced protein sequence of the heavy chain of rat brain dynein shows significant similarity to sea urchin flagellar beta-dynein (27.0% identical) and to Dictyostelium cytoplasmic dynein (53.5% identical) throughout the entire sequence. The heavy chain of rat brain (cytoplasmic) dynein contains four putative nucleotide-binding consensus sequences [GX4GK(T/S)] in the central one-third region that are highly similar to those of sea urchin and Dictyostelium dyneins. The N-terminal one-third of the heavy chain of rat brain (cytoplasmic) dynein shows high similarity (43.8% identical) to that of Dictyostelium cytoplasmic dynein but poor similarity (19.4% identical) to that of sea urchin flagellar dynein. These results suggested that the C-terminal two-thirds of the dynein molecule is conserved and plays an essential role in microtubule-dependent motility activity, whereas the N-terminal regions are different between cytoplasmic and flagellar dyneins.

Amino Acid Sequence↗
PubMed1993

Experimental murine protoporphyria induced by griseofulvin (GF): the relationship between hepatic porphyrin levels and liver function test values in mice treated with GF.

To investigate the hepatic abnormalities accompanying experimental protoporphyria due to griseofulvin (GF), liver function test values and porphyrin levels in mice were assayed at days 2, 4, 8, and 16 after starting the administration of 0.5% GF feed. Furthermore, in an attempt to elucidate the harmful effects of GF on liver functions, the above mentioned assay was also performed after the feed was discontinued in mice given 0.5% GF feed for 16 days. The hepatic protoporphyrin (PP) level had already risen by day 2, but the erythrocytic PP level was within normal limits at that time. Hepatic PP levels increased gradually, followed by an increase in erythrocytic PP levels. The variation in liver function test values roughly paralleled the porphyrin levels. Over the time span of the response to GF, the variations in the serum glutamate oxaloacetate transaminase (S-GOT) levels, serum glutamate pyruvate transaminase (S-GPT) levels, and leucine amino peptidase (LAP) levels resembled those in hepatic PP. On the other hand, the changes in alkaline phosphatase (ALP) levels paralleled those of the erythrocytic PP levels. Erythrocytic and fecal protoporphyrin levels decreased to the normal level one month after the discontinuation of GF administration, but the hepatic protoporphyrin level still was 53.6 times higher than the normal level two months after switching to normal feed. The values of liver function tests had returned to within the normal range after one month. By the fourth day after the administration of GF, a brown pigmented material could be observed around the hepatocytes and the Glisson sheath; the amount of this material increased day by day.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

A case of a giant schwannoma on the extremities.

A 52-year-old Japanese female with a human head sized lump on the medial femoral region of her right thigh is described. The histopathological diagnosis after the excision of the tumor was an ordinary type of schwannoma composed of two types of tissue, Antoni types A and B. The tumor was 20 x 15 x 12 cm in size and 2250 g in weight; this is probably the biggest of all the reported cases of schwannoma on the extremities in Japan.

Female↗