Biomedical subjects

H Yamada

Publications and source records attributed to H Yamada.

At least 199 records · Page 11Linked to original sources

PubMed2001

Is lymphadenectomy needed for all submucosal gastric cancers?

OBJECTIVE: To find out if it is feasible to extend the indication for local resection of submucosal gastric cancer without increasing the risk of lymph node metastases. DESIGN: Retrospective study. SETTING: University hospital, Japan. SUBJECTS: 104 patients with gastric cancer confined to the submucosal layer who underwent conventional gastrectomy with lymphadenectomy. INTERVENTIONS: The risk of nodal metastases was analysed retrospectively depending on the depth of submucosal invasion, size of the tumour, and other clinicopathological findings. MAIN OUTCOME MEASURES: The degree of submucosal invasion, size of the tumour, and incidence of lymph node metastasis. RESULTS: 15/104 patients (14%) had lymph node metastases. No patient in whom submucosal invasion was less than 500 microm or tumour was less than 15 mm in diameter developed lymph node metastases. Fewer patients had lymphatic permeation (37/89) and venous involvement (21/89) in the group without lymph node metastases. CONCLUSION: These data seem to support the hypothesis that early, minimally invasive, gastric cancer measuring < 15 mm in diameter could be treated by endoscopic mucosal or local resection, and gastrectomy with lymphadenectomy might be unnecessary.

Adult↗

PubMed2001

Intravenous chlorhexidine gluconate causing acute respiratory distress syndrome.

CASE REPORT: A 67-year-old man undergoing a colectomy for colon cancer was unintentionally administered 0.8 mg of chlorhexidine gluconate intravenously and subsequently developed acute respiratory distress syndrome. The operation was discontinued immediately. Respiratory failure progressed despite three cycles of plasma exchange beginning on day 1. Extracorporeal membrane oxygenation for 72 h beginning on day 3 was associated with dramatic improvement. The patient showed complete recovery of intellectual function and subsequently underwent a colectomy with lymph node dissection for colon cancer. CONCLUSION: For acute respiratory distress syndrome secondary to chlorhexidine gluconate intoxication, consideration should be given to the treatment of initial respiratory distress and subsequent pneumonia. The benefit of extracorporeal membrane oxygenation and plasma exchange may merit further investigation.

Aged↗

PubMed2001

Odorant-induced hyperpolarization and suppression of cAMP-activated current in newt olfactory receptor neurons.

Although many studies have reported that odorants can elicit inhibitory responses as well as excitatory responses in vertebrate olfactory receptor neurons, the cellular mechanisms that underlie this inhibition are unclear. Here we examine the inhibitory effect of odorants on newt olfactory receptor neurons using whole cell patch clamp recording. At high concentrations, odorant stimulation decreased the membrane conductance and inhibited depolarization. Various odorants (anisole, isoamyl acetate, cineole, limonene and isovaleric acid) suppressed the depolarizing current in a dose-dependent manner. Furthermore, one odorant could suppress the depolarization caused by another odorant. The depolarization caused by isoamyl acetate was inhibited by anisole in cells that were excited by isoamyl acetate but not by anisole. Odorants were able to hyperpolarize cells that were depolarized by cAMP-induced conductance. Given that this inhibitory effect of odorants can affect excitation caused by other odorants, we suggest that it might play a role in coding odorants in olfactory receptor neurons.

1-Methyl-3-isobutylxanthine↗

PubMed2001

Inducible expression of a CC chemokine liver- and activation-regulated chemokine (LARC)/macrophage inflammatory protein (MIP)-3 alpha/CCL20 by epidermal keratinocytes and its role in atopic dermatitis.

Liver-and activation-regulated chemokine (LARC)/macrophage inflammatory protein (MIP)-3alpha/CCL20 is a CC chemokine which is constitutively expressed by follicle-associated epithelial cells in the mucosa, and attracts cells expressing CCR6 such as immature dendritic cells and alpha(4)beta(7)(high) intestine-seeking memory T cells. Here, we examine LARC/CCL20 expression in the skin. LARC/CCL20 mRNA and protein were induced in primary human keratinocytes upon stimulation with proinflammatory cytokines such as IL-1alpha and tumor necrosis factor (TNF)-alpha. In mice, intradermal injection of IL-1alpha and TNF-alpha rapidly induced a local accumulation of transcripts for LARC/CCL20 and its receptor CCR6 with a lag of several hours in the latter. In humans, immunostaining of LARC/CCL20 was weak if any in normal skin tissues but strongly augmented in lesional skin tissues with atopic dermatitis. Furthermore, massive infiltration of cells with markers such as CD1a, CD3 or HLA-DR was present in atopic skin lesions. Many infiltrating cells were also found to be CCR6(+) by a newly generated monoclonal anti-CCR6. However, Langerhans cells residing within the epidermis were hardly stained by anti-CCR6 in normal and atopic skin tissues. Furthermore, plasma levels of LARC/CCL20 were found to be elevated in patients with atopic dermatitis. Collectively, our results suggest that epidermal keratinocytes produce LARC/CCL20 upon stimulation with proinflammatory cytokines such as IL-1alpha and TNF-alpha, and attract CCR6-expressing immature dendritic cells and memory/effector T cells into the dermis of inflamed skin such as atopic dermatitis. LARC/CCL20 may not, however, play a major role in homeostatic migration of Langerhans cells into the skin.

Adult↗

PubMed2001

Cryoprotective effect of the serine-rich repetitive sequence in silk protein sericin.

The silk proteins, fibroin and sericin, are produced in the silk gland of Bombyx mori, and hydrophilic sericin envelops fibroin with successive sticky layers in the formation of a cocoon. To study the biological functions of sericin, we focused on the serine-rich sericin peptide consisting of 38 amino acids, which is a highly conserved and internally repetitive sequence of a sericin protein. The corresponding gene was chemically synthesized, and the PCR-amplified gene was ligated to oligomerize sericin peptide and fused at the amino terminus to a His-tagged and proteolytic cleavage sequence in an inducible expression vector. When the dimers of sericin peptides were overexpressed in Escherichia coli, the transformants showed a prominent increase in cell viability after freezing in medium. Further, the purified dimeric sericin peptide from E. coli was found to be effective in protecting lactate dehydrogenase from denaturation caused by freeze-thaw. Both of these protective effects against freezing stress in cells and proteins were also observed with sericin hydrolysate. These results indicate that this unique sericin peptide, like sericin, has a high cryoprotective activity and will be valuable as a new biomaterial for industrial use.

Amino Acid Sequence↗

PubMed2001

The Arabidopsis sensor His-kinase, AHk4, can respond to cytokinins.

His-to-Asp (His-->Asp) phosphorelay mechanisms are presumably involved in propagation of certain environmental stimuli, including phytohormones, in Arabidopsis thaliana. In addition to the previously characterized His-kinases, namely, the ETR1 family of ethylene receptors, CKI1 cytokinin-sensor, and ATHK1 osomo-sensor, this higher plant has three more His-kinases (named AHK2, AHK3, and AHK4). By employing the well-known His-->Asp phosphorelay systems in both the fission yeast and Escherichia coli, evidence is presented showing that the AHK4 His-kinase has an ability to serve as a cytokinin-responsive environmental sensor. Taking advantage of this AHK4-dependent His-->Asp phosphorelay system in E. coli, a phosphorelay interaction between the Arabidopsis His-kinase and histidine-containing phosphotransmitters (AHPs) was also demonstrated for the first time.

Arabidopsis↗

PubMed2001

The Arabidopsis AHK4 histidine kinase is a cytokinin-binding receptor that transduces cytokinin signals across the membrane.

Common histidine-to-aspartate (His-->Asp) phosphorelay is a paradigm of signal transduction in both prokaryotes and eukaryotes for the propagation of certain environmental stimuli, in which histidine (His)-kinases play central roles as sensors for environmental signals. For the higher plant, Arabidopsis thaliana, it was recently suggested that the His-kinase (AHK4 / CRE1 / WOL) is a sensor for cytokinins, which are a class of plant hormones important for the regulation of cell division and differentiation. Interestingly, AHK4 is capable of functioning as a cytokinin sensor in the eubacterium, Escherichia coli (Suzuki et al. 2001, Plant Cell Physiol. 42: 107). Here we further show that AHK4 is a primary receptor that directly binds a variety of natural and synthetic cytokinins (e.g. not only N(6)-substituted aminopurines such as isopentenyl-adenine, trans-zeatin, benzyl-adenine, but also diphenylurea derivatives such as thidiazuron), in a highly specific manner (K(d) = 4.55+/-0.48x10(-9) M). AHK4 has a presumed extracellular domain, within which a single amino acid substitution (Thr-301 to Ile) was shown to result in loss of its ability to bind cytokinins. This particular mutation corresponds to the previously reported wol allele (wooden leg) that causes a striking phenotype defective in vascular morphogenesis. Collectively, evidence is presented that AHK4 and its homologues (AHK3 and possibly AHK2) are receptor kinases that can transduce cytokinin signals across the plasma membrane of A. thaliana.

Adenine↗

PubMed2001

Hip adductor muscle strength in patients with varus deformed knee.

The isometric muscle strength of the muscles around 49 medial compartmental osteoarthritic knees of 32 women was measured quantitatively using a Musculater GT-50 (osteoarthritis group). The patients pushed up a pad containing an electrical sensor and values were compared with those obtained from the nonaffected knees of subjects (control group). The mean age of the patients in the osteoarthritis group was 62.3 years (range, 43-78 years). The control group consisted of 13 women (13 knees) with a mean age of 60.5 years (range, 49-73 years). In the osteoarthritis group, the medial joint space was preserved in 17 knees (Grade A), 23 knees had narrowing of the joint space (Grade 2), and nine knees showed joint space obliteration (Grade 3). Quadriceps strength was significantly weaker in Grade 2 knees than in Grade 0 knees; however, there was no significant difference in quadriceps to hamstrings ratio between each grade. The hip adductors to hamstrings ratio was significantly greater in Grade 2 knees than in Grade 0 knees, and was greater in Grade 3 knees than in Grade 0, Grade 1, and Grade 2 knees. The findings suggested that in patients with medial compartmental osteoarthritis of the knee, the hip adductor muscles may become strengthened to decrease varus decrease varus deformity of the limb.

Adult↗

PubMed2001

Hemodynamic and metabolic effects of low-dose vasopressin infusions in vasodilatory septic shock.

OBJECTIVE: To investigate the physiologic effects of exogenous vasopressin as a potential alternative to traditional high-dose catecholamine therapy for septic patients with vascular hyporeactivity to catecholamines. DESIGN: Prospective, case-controlled study. SETTING: Intensive care unit of a university hospital. PATIENTS: Vasopressin was infused in 16 critically ill septic patients who remained persistently hypotensive despite infusions of pharmacologic doses of catecholamines. INTERVENTION: Continuous intravenous infusion of vasopressin at 0.04 units/min for 16 hrs, in place of escalating the amount of catecholamines being infused. MEASUREMENTS AND MAIN RESULTS: After administration of vasopressin, systemic vascular resistance and mean arterial pressure were immediately and significantly increased in comparison with the values obtained just before vasopressin. When the vasopressin infusions were discontinued, mean arterial pressure decreased immediately and dramatically. We did not detect any obvious adverse cardiac effects during the vasopressin infusions. Vasopressin had no effect on other hemodynamic parameters or any of the metabolic parameters studied, including measures of oxygenation, plasma glucose, or electrolytes. Urine output increased significantly during the administration of vasopressin, although this effect may be nonspecific. Lactate concentrations decreased, particularly in the survival group, but the decreases were not significant. Overall survival was 56%. CONCLUSIONS: Low-dose vasopressin infusions increased mean arterial pressure, systemic vascular resistance, and urine output in patients with vasodilatory septic shock and hyporesponsiveness to catecholamines. The data indicate that low-dose vasopressin infusions may be useful in treating hypotension in these patients.

Adolescent↗

PubMed2001

Activation of alveolar macrophages in acid-injured lung in rats: different effects of pentoxifylline on tumor necrosis factor-alpha and nitric oxide production.

OBJECTIVE: To determine whether acid instillation augments tumor necrosis factor-alpha and nitric oxide production by alveolar macrophages in rats, and to study the effects of treatment with pentoxifylline before acid instillation on the production of these inflammatory mediators. DESIGN: Controlled laboratory investigation on tumor necrosis factor-alpha and nitric oxide production by alveolar macrophages of rats that had acid-induced lung injury. SETTING: University research laboratory. SUBJECT: Alveolar macrophages of rats. INTERVENTIONS: Alveolar macrophages were recovered by bronchoalveolar lavage at 4, 10, 16, 24, and 72 hrs after unilateral hydrochloric acid (pH, 1.0; volume, 0.1 mL) instillation into the lungs of rats. Alveolar macrophages then were cultured with or without lipopolysaccharide. One group of rats was pretreated with pentoxifylline before acid instillation. MEASUREMENTS AND MAIN RESULTS: Alveolar macrophages from both acid-instilled and contralateral lungs, which had recovered 24 hrs after acid instillation, produced significantly greater tumor necrosis factor-alpha and nitric oxide. Subsequent exposure to lipopolysaccharide, as a surrogate for bacterial infection, further promoted tumor necrosis factor-alpha and nitric oxide release. Alveolar macrophages from rats pretreated with pentoxifylline before acid instillation produced significantly less tumor necrosis factor-alpha and did not overproduce tumor necrosis factor-alpha when exposed to lipopolysaccharide. In contrast, pretreatment with pentoxifylline had no effect on nitric oxide production by alveolar macrophages. CONCLUSIONS: Acid instillation stimulates alveolar macrophages to produce tumor necrosis factor-alpha and nitric oxide. Pentoxifylline preserved innate production of tumor necrosis factor-alpha to lipopolysaccharide and did not inhibit the production of bactericidal nitric oxide. This may partly explain why pentoxifylline reduces acid aspiration-induced lung injury while maintaining the host's ability to combat bacterial infection after acid aspiration.

Animals↗

PubMed2001

Synchronous double cancer of the stomach and rectum with situs inversus totalis and polysplenia syndrome.

Situs solitus refers to the normal arrangement of body organs. Situs inversus totalis is a complete mirror image or reverse isomeric form of the thoracic and abdominal viscera. Any arrangement of organs between these two extremes is designated by heterotaxia. Several patterns of vascular and visceral abnormalities are associated with heterotaxia, and two loosely defined syndromes of splenic anomalies (asplenia and polysplenia) are most common. We present the case of a 71-year-old woman with situs inversus totalis and polysplenia syndrome who developed synchronous double cancer originating from the stomach and rectum. Abdominal manifestations were situs inversus totalis combined with multiple lobulated spleen, azygous continuation of the interrupted inferior vena cava, direct drainage of hepatic vein to left atrium, preduodenal portal vein, short pancreas, incomplete rotation of the colon, and malrotation of the intestine. Histologically, gastric cancer was diagnosed as papillary adenocarcinoma and rectal cancer, as moderately differentiated adenocarcinoma. The patient was successfully treated with total gastrectomy for gastric cancer and low-anterior resection of the rectum for rectal cancer.

Adenocarcinoma↗

PubMed2001

Three-dimensional structure of human RNase 1 delta N7 at 1.9 A resolution.

Human pancreatic ribonuclease 1 (RNase 1) is considered to be the human counterpart of bovine pancreatic RNase A. Truncation of seven amino-acid residues from the amino-terminal sequence resulted in RNase 1 Delta N7, which has a reduced ribonucleolytic activity and a lower affinity for the human placental RNase inhibitor (PRI). This RNase 1 variant has been cloned, heterologously overexpressed, purified and crystallized. Its crystal structure has been determined and refined using data to 1.9 A resolution. The molecule displays the alpha + beta folding topology typical of members of the RNase A superfamily. The main distinct features found in RNase 1 Delta N7 are basically located in three loops affecting the fitting of the enzyme to the active site of subtilisin and the shape of the B2 subsite. These changes, taken with the lack of the catalytically active residue Lys7, may explain the reduced affinity of RNase 1 Delta N7 for PRI and the low ribonucleolytic activity of the protein when compared with the native enzyme.

Amino Acid Sequence↗

PubMed2001

Role of interleukin (IL)-1 type 1 receptor in mycobacterial infection.

It is important to gain a better understanding of IL-1-mediated signaling events in mycobacterial infection. In order to clarify the role of IL-1 receptor type 1 (IL-1 R1) in IL-1 R1, knockout (KO) mice were infected with either Mycobacterium tuberculosis H37Rv or Kurono strain by the respiratory route, and their ability to control mycobacterial growth, pulmonary granuloma formation, and cytokine mRNA expression was investigated. IL-1 R1 KO mice developed significantly larger (P< 0.01) granulomatous lesions with neutrophil infiltration in their lungs than wild-type mice did after infection with the M. tuberculosis Kurono strain. The number of mycobacterial colonies in lungs and spleen increased from five weeks post-infection. Interferon-y production by spleen cells was low in IL-1 R1 KO mice. It is concluded that the IL-1 R1 is essential for IL-1-mediated signaling events in mycobacterial infection.

Animals↗

PubMed2001

Management of pregnancy with congenital antithrombin III deficiency: two case reports and a review of the literature.

Women with antithrombin (AT) III deficiency are prone to pregnancy-associated venous thromboembolism. We report 2 cases with genetically confirmed ATIII deficiency, one with a mutation in exon 3A and the other with an exon 4 deletion, in whom the pregnancies were successfully managed with prophylactic therapies for thrombosis. A 35-year-old pregnant woman was treated with intravenous infusions of ATIII concentrate alone, and the other 22-year-old pregnant woman was mainly treated with subcutaneous injections of heparin and oral low-dose aspirin therapy. Both pregnancies resulted in vaginal deliveries of healthy neonates. The literature concerning prophylactic therapies for thrombosis in ATIII deficiency-complicated pregnancy is reviewed, and the clinical problems, including the adverse effects of the therapies, are discussed.

Adult↗

PubMed2001

Angiosarcoma of vagina successfully treated with interleukin-2 therapy and chemotherapy: a case report.

We report a case of angiosarcoma of the vagina in a 61-year-old woman who had undergone radical hysterectomy and pelvic irradiation for uterine cervical adenocarcinoma 14 years previously. Combination chemotherapy (cyclophosphamide, vincristine, doxorubicin and dacarbazine) and interleukin-2 induced complete remission of the tumor. The patient remained free from disease for 15 months.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2001

Total alpha-fetoprotein and Lens culinaris agglutinin-reactive alpha-fetoprotein in fetal chromosomal abnormalities.

OBJECTIVE: To examine the differences in multiples of the median (MoM) of total alpha-fetoprotein, and the proportion of Lens culinaris agglutinin reactive alpha-fetoprotein (% alpha-fetoprotein-L2 + L3) in the maternal serum and amniotic fluid of pregnant women whose fetuses were diagnosed with autosomal or sex chromosomal abnormalities. DESIGN: Prospective consecutive series. SETTING: University hospital. SAMPLE: Maternal sera and amniotic fluids from 46 pregnant women with trisomy 21 fetuses, 10 pregnant women with trisomy 18 fetuses, one pregnant woman with a trisomy 13 fetus, six pregnant women with fetal sex chromosomal abnormalities, and 100 pregnant women for whom the fetal karyotype was diagnosed as normal following a genetic amniocentesis. RESULTS: The proportion of alpha-fetoprotein-L2 + L3 in maternal serum for trisomy 21 (40.3%. P < 0.0001) and trisomy 18 (39.8%, P < 0.05) showed a significantly higher value compared with normal (32.6%). The proportion of alpha-fetoprotein-L2 + L3 in amniotic fluid was significantly higher (P < 0.0001) for trisomy 21 (46.6%) than for a normal karyotype (41.5%). Only for the trisomy 21 group was there a strong correlation in the % alpha-fetoprotein-L2 + L3 between maternal serum and amniotic fluid (r = 0.840, P < 0.0001). For all groups, there was no correlation between alpha-fetoprotein MoM and % alpha-fetoprotein-L2 + L3 in maternal serum and amniotic fluid. CONCLUSION: The proportion of alpha-fetoprotein-L2 + L3 in maternal serum is an appropriate choice for a trisomy 21 biochemical marker, and it is possible that combining alpha-fetoprotein-L2 + L3 analysis with assays of alpha-fetoprotein in maternal serum could further improve the sensitivity and specificity of multiple marker screening.

Adult↗

PubMed2001

High NK cell activity in early pregnancy correlates with subsequent abortion with normal chromosomes in women with recurrent abortion.

PROBLEM: The aim of this study was to assess the role of natural killer (NK) cells in pregnant women with a history of recurrent spontaneous abortion (RSA). METHOD OF STUDY: Consecutive 66 pregnant women with a history of RSA were prospectively assessed for peripheral NK cell activity, percentage of the NK cell subsets, and subsequent pregnancy outcome. RESULTS: NK cell activity in women with subsequent live birth (group I) at 4-5 gestational weeks (GW) (mean +/- SD, 32.5 +/- 12.31%) significantly decreased at 6-7 GW (28.1 +/- 12.1%) and at 8 9 GW (28.0 +/- 11.8%). NK cell activity in women with subsequent abortion with normal chromosomes (group II) at 6 7 GW (41.2 +/- 19.0%) was significantly higher than that in group I women, while NK cell activity at 6-7 GW in women with subsequent abortion with abnormal chromosomes (group III) was the same as the level in group I women. CONCLUSIONS: High NK cell activity at 6-7 GW correlates with subsequent abortion with normal chromosomes.

Abortion, Habitual↗

PubMed2001

Relative importance of NF-kappaB p50 in mycobacterial infection.

To understand the role of NF-kappaB in the development of murine tuberculosis in vivo, NF-kappaB p50 knockout mice were infected with Mycobacterium tuberculosis by placing them in the exposure chamber of an airborne-infection apparatus. These mice developed multifocal necrotic pulmonary lesions or lobar pneumonia. Compared with the levels in wild-type mice, pulmonary inducible nitric oxide synthase, interleukin-2 (IL-2), gamma interferon, and tumor necrosis factor alpha mRNA levels were significantly low but expression of IL-10 and transforming growth factor beta mRNAs were within the normal ranges. The pulmonary IL-6 mRNA expression level was higher. Therefore, NF-kappaB and its interaction with host cells play an important role in the pathogenesis of tuberculosis.

Animals↗