Biomedical subjects

A Imai

Publications and source records attributed to A Imai.

At least 37 records · Page 2Linked to original sources

PubMed2001

Influence of age on the results of brachytherapy for early tongue cancer.

PURPOSE: To determine the influence of elder age on the results of brachytherapy for early (T1-2 N0 M0) oral tongue cancer and examine the compatibility of low-dose rate (LDR) with high-dose rate (HDR) brachytherapy. METHODS AND MATERIALS: We analyzed 591 patients treated at Osaka University Hospital between 1967 and 1999. We compared the results of radiotherapy for 156 elderly patients (137 LDR and 19 HDR) 65 years of age or older and 435 patients (383 LDR and 52 HDR) less than 65 years of age. RESULTS: HDR brachytherapy showed the same local control rate as LDR brachytherapy (81% at 3 years). Elderly patients showed a poorer local control rate (75% at 3 years) than the younger group (83% at 3 years)(p = 0.002). Multivariate analysis identified age as the only prognostic factor for local control (p = 0.002). CONCLUSIONS: HDR brachytherapy achieved the same result as LDR brachytherapy. However, the elderly patient showed a higher rate of local recurrence after brachytherapy.

Adult↗

PubMed2001

mRNA expression of membrane-fusion-related proteins in rat parotid gland.

The soluble N-ethylmaleimide-sensitive fusion (NSF) attachment protein (SNAP) receptor (SNARE) hypothesis has been applied to exocytosis in salivary glands. The expression of SNARE proteins has not been well investigated in the parotid gland. In this study, the mRNA expression of SNAREs and membrane-fusion-related proteins were investigated in the rat parotid by reverse transcriptase-polymerase chain reaction (RT-PCR). All syntaxins except syntaxin 1, and the vesicle-associated membrane proteins (VAMP) except VAMP-7, NSF, SNAP-23 and alpha-SNAP, were expressed for the SNAREs in rat parotid. Synaptotagmins 3, 4 and 11, Munc18s (1, 2 and 3), syncollin, prenylated Rab acceptor (PRA1), zygin 1, pantophysin and cellugyrin, which are the other membrane-fusion-related proteins, were also detected, but neither Rim nor rabphilin 3A, which have high specificity of binding to Rab 3A, were found. mRNA expressions of many SNAREs and of the membrane-fusion-proteins suggest novel interactions for the regulation of salivary exocytosis.

Animals↗

PubMed2001

Fractionation and characterization of dissolved organic matter in a shallow eutrophic lake, its inflowing rivers, and other organic matter sources.

Dissolved organic matter (DOM) in water from eutrophic Lake Kasumigaura, its inflowing rivers, and several other DOM sources in the lake catchment area was fractionated using resin adsorbents into five classes: aquatic humic substances (AHS), hydrophobic neutrals (HoN), hydrophilic acids (HiA), bases (BaS), and hydrophilic neutrals (HiN). The DOM-fraction distribution pattern and the ultraviolet absorbance to dissolved organic carbon ratio (UV/DOC ratio) were found remarkably effective for evaluating the characteristics of DOM in water. DOM-fraction distribution patterns were significantly different depending on the origin of the sample. AHS and HiA were found to be the dominant fractions in DOM in all samples studied. HiA prevailed over AHS in the lake water, whereas AHS were slightly more abundant than HiA in the river waters. AHS were in the great majority in forest streams and plowed-field percolates. HiA abounded in paddy-field outflow, domestic sewage, and sewage-treatment-plant effluent. Only domestic sewage contained a significant amount of HoN. The UV/DOC ratio also varied depending on the origin of the sample: the ratios in total DOM, AHS, and HiA were greater in river waters than in the lake water. The greatest ratio of AHS was found in paddy-field outflow and the lowest in domestic sewage. The UV/DOC ratios in the sewage-treatment-plant effluent were very similar to those in the lake water.

Absorption↗

PubMed2001

The future demand for and structural problems of Japanese radiotherapy.

BACKGROUND: Recently, as the number of elderly people in Japan is growing, so is the number of new cancer cases. The number of patients treated with radiotherapy is therefore also on the increase, so that it is important to estimate the future demand for radiotherapy and to make preparations for it. METHODS: All the surveys were conducted for 106 facilities selected randomly out of 556 radiotherapy facilities in Japan. To obtain trends in the number of new cancer patients treated with radiotherapy in Japan, we conducted a survey with a self-administered mail questionnaire designed to obtain the number of new patients treated with radiotherapy for each year of the past decade (1990-99). The future number of new patients treated with radiotherapy was estimated from the data thus obtained. To investigate structural problems of Japanese radiotherapy, surveys about the number of treatment machines and full-time equivalent (FTE) radiation oncologists were conducted according to data from the Japanese Society for Therapeutic Radiology and Oncology (JASTRO) structure survey and the Patterns of Care Study (PCS). We also compared the structure of Japanese radiotherapy with that in the USA. RESULTS: The number of patients treated with radiotherapy has increased for every institutional stratum, with an overall increase of 1.4-fold over the past 10 years in Japan. It is estimated that the number of cancer patients treated with radiotherapy will reach 190 000 in 2015. In Japanese non-academic institutions, less than one FTE radiation oncologist has been managing many of these patients. In both equipment and manpower, academic institutions exceed nonacademic institutions. CONCLUSION: The future demand for Japanese radiotherapy will grow substantially, so that it is of vital importance to prepare for it. Specifically, the number of FTE radiation oncologists must be increased.

Cancer Care Facilities↗

PubMed2001

Gynecologic tumors and symptoms in childhood and adolescence.

Although tumors are rarely seen in girls, they should be considered in differential diagnosis because of the high incidence of potential malignancy in genital tumors compared with adults. Ultrasonography can quickly evaluate the underlying cause of genital symptoms or signs and allow timely intervention, while magnetic resonance imaging accurately measures the extent and location of the vaginal lesion. As a result of modern progress in the chemotherapy regimens, the prompt and precise detection of either benign or malignant tumors can lead to both cure and preservation of fertility with conservative surgery whenever possible. With the widespread use of obstetrical ultrasonography, fetal abdominal tumors are being diagnosed with increasing frequency. Most of these tumors will undergo spontaneous resolution within the first few months of life.

Adolescent↗

PubMed2001

Treatment of ischial pressure ulcers with a posteromedial thigh fasciocutaneous flap.

This study describes the use of the posteromedial thigh fasciocutaneous flap for the treatment of ischial pressure sores. The authors prefer this flap because it is the fasciocutaneous flap nearest to the ischial region, it is easy to raise, and it causes no donor-site morbidity. In this study, 11 ischial pressure sores in 10 paraplegic patients were closed using the posteromedial thigh fasciocutaneous flaps. All flaps survived, although two caused distal necrosis; after these same two flaps were readvanced, they survived. After an average follow-up time of 77 months, seven of the 10 patients have had no recurrence of ulcers. This fasciocutaneous flap was previously described by Wang et al. However, this study revealed that the arrangement of the vascular pedicle was different from that described by Wang et al. To reveal the vascular supply of this flap, anatomic dissections were conducted. The source of circulation to this flap was the suprafascial vascular plexus, in addition to the musculocutaneous perforator. The dominant pedicle was the musculocutaneous perforator from either the adductor magnus muscle or the gracilis muscle. The key to safe elevation of this flap was the accurate outlining of the skin island directly over the vascular pedicle and the preservation of the proximal fascial continuity. Of the 11 flaps, two viability problems occurred. These partial flap losses resulted from the failure to properly include the perforator. It is the authors' conclusion that the width of the flap should be greater than 5 cm. In addition, it is safe to make a flap within a 1:3 base-to-length ratio in a fatty, diabetic patient. This posteromedial thigh fasciocutaneous flap was found to be a valuable alternative for reconstruction of primary or recurrent ischial pressure ulcers.

Adult↗

PubMed2001

Markedly increased nasal blockage by intranasal leukotriene D4 in an experimental allergic rhinitis model: contribution of dilated mucosal blood vessels.

We examined whether nasal hyperresponsiveness to leukotriene (LT) D4 is seen in our allergic rhinitis model, which showed sneezing and biphasic nasal blockage by repeated antigen inhalation challenge, and whether a dilatation of mucosal blood vessels contributes to this hyperresponsiveness. Nasal blockage [increase of specific airway resistance (sRaw)] was indexed as nasal (hyper)responsiveness. The sensitized-challenged guinea pig showed a remarkable dose-dependent increase in sRaw by intranasal instillation of LTD4 (10 microl/nostril) at 10(-10) to 10(-6) M 10 h and 2 days but not 7 days after the challenge. The increase in sRaw induced by LTD4 was largely blocked by pranlukast or naphazoline, and this was dose-dependently suppressed by N(omega)-nitro-L-arginine methyl ester. Sodium nitroprusside induced an elevation of sRaw in the sensitized-challenged animal in the hyperresponsiveness state, but the degree did not differ from that in the non-sensitized-non-challenged group. The amount of NO2- and NO3- in nasal cavity lavage fluid after LTD4 instillation in the sensitized-challenged animal in the hyperresponsiveness state was significantly greater than that before the instillation. These results demonstrate that the hyperresponsiveness to LTD4 acquired by repeated antigen challenge is mainly due to dilatation of nasal blood vessels, which can be related to hyperproduction of nitric oxide through cysteinyl LT1-receptor activation.

Airway Resistance↗

PubMed2001

Serum total cholesterol of new students enrolled at Okayama University: trend during 1989-1998.

To clarify the trend of hypercholesterolemia in Japanese adolescents, we investigated the serial changes in body mass index (BMI) and serum total cholesterol (TC) concentrations among 5,700 new students enrolled at Okayama University in 1989, 1993, and 1998. After confirming the stability of the TC assay of serum samples stored at -80 degrees C, we measured serum TC levels in stored serum samples using an automated assay system. Although serum TC levels were higher in females than in males, these levels correlated weakly and positively with BMI (r = 0.21, P < 0. 001) in males but not in females. Serum TC concentrations progressively increased from 1989-1998 in both sexes, irrespective of changes in BMI. In subjects with normal BMI (> or = 19 and < 23 kg/m2), a significant increase in serum TC was noted from 1989-1998 in both males (157.2 +/- 1.0 to 163.6 +/- 0.9 mg/dl) and females (172.0 +/- 1.1 to 175.6 +/- 1.0 mg/dl). Our results indicate on increased incidence of hypercholesterolemia even in nonobese young Japanese adolescents. A concerted effort by health and education officials together with parents is necessary to prevent a further rise in the incidence of hypercholesterolemia among young Japanese.

Adolescent↗

PubMed2000

High-dose-rate interstitial brachytherapy as a monotherapy for localized prostate cancer: treatment description and preliminary results of a phase I/II clinical trial.

PURPOSE: To improve results for localized prostate cancer, a prospective clinical trial of hyperfractionated Iridium-192 high-dose-rate (HDR) brachytherapy as a monotherapy was initiated. METHODS AND MATERIALS: Between May 1995 and September 1998, 22 implants were performed on 22 patients with localized prostate cancer (T1:T2:T3:T4 = 4:6:9:3) at Osaka University Hospital. Nineteen patients, who had T3-T4 tumors or pretreatment PSA >/= 20.0 ng/mL, received hormone therapy. No patient had external beam radiation. Transperineal needle implants using real-time ultrasound guidance were performed, followed by dose optimization program. Patients were irradiated twice a day, with a time interval of more than 6 h. Total dose was 48 Gy/8 fractions/5 days or 54 Gy/9 fractions/5 days. Acute toxicity was scored using the Radiation Therapy Oncology Group (RTOG) radiation morbidity scoring criteria. Median follow-up time was 31 months. RESULTS: HDR brachytherapy as a monotherapy was well-tolerated. No significant intra- or peri-operative complications occurred. No patient experienced acute toxicity of grade 3 or more. PSA levels normalized in 95% of patients within 20 months after irradiation. Four-year clinical and biochemical relapse-free rates were 95% and 55%, respectively. CONCLUSION: Acute toxicity with this method was acceptable. Further patient accrual and longer follow-up will allow comparison to other techniques.

Aged↗

PubMed2000

Testosterone modulates serum leptin concentrations in a male patient with hypothalamic hypogonadism.

Serial measurements of body mass index (BMI), serum concentrations of testosterone (T), estradiol (E) and leptin (L) were performed before and after gonadotropin (Gn) therapy in an 18-year-old male subject (BMI 25.4 kg/m2) with idiopathic hypothalamic hypogonadism (IHH). We also measured the BMI and serum concentrations of L in 99 age-matched healthy subjects. Serum L correlated significantly with BMI in control subjects (r=0.84, p<0.0001). Baseline serum concentrations of L in our case were markedly high and both T and E were very low, but Gn therapy resulted in a gradual decrease in L and improvement in T and E, finally reaching the control levels of BMI-matched subjects. Our results demonstrate that T is a powerful negative modulator of serum L independent of BMI in conditions associated with low T levels, such as IHH.

Adolescent↗

PubMed2000

Expression, characterization, and localization of Rab26, a low molecular weight GTP-binding protein, in the rat parotid gland.

We investigated the expression of the genes encoding Rab proteins, low molecular weight GTP-binding proteins, in the rat parotid gland by the use of reverse transcription-polymerase chain reaction, and detected cDNAs of Rab3D, Rab4, and Rab26. We further examined the characteristics and localization of Rab26 by western blotting and light and electron microscopic immunocytochemistry. Western blotting using an antibody against the Rab26-specific, C-terminal peptide detected the His-tagged Rab26 protein as a single 27-kDa band. This band also displayed binding to [alpha-32P]GTP. The fraction containing secretory granule membranes in an acinar cell homogenate was immunostained with the antibody. Supporting this, the immunocytochemical reaction for Rab26 was localized immediately around secretory granules in the acinar cells. The immunostaining disappeared from the acinar cells after treatment of rats with isoproterenol. These findings suggest that Rab26 participates in the regulated secretion of granules and functionally belongs to the Rab3 group.

Animals↗

PubMed2000

GnRH receptor and apoptotic signaling.

In addition to its hypophysiotropic action, gonadotropin-releasing hormone (GnRH) can modify activity in extrapituitary organs and peripheral tumors. GnRH analogs are the preferred treatment for advanced and even metastatic or recurring carcinomas in vivo and in vitro. Hormone-responsive tumors undergo apoptosis with the appropriate stimulus; GnRH-induced tumor growth arrest may result from stimulated apoptotic cell death. The sensitivity of tumors and normal tissue to GnRH is strongly associated with the possession of receptors for GnRH as well as other hormonal control. Despite the lack of a precise apoptotic signaling cascade through GnRH receptors, biochemical events observed within a plasma membrane appear to constitute the most convincing evidence that the membrane event is primarily stimulated during cell activation by GnRH. GnRH receptors in tumors differ from those in pituitary gonadotrophs in some aspects, in particular with regard to the transmembrane signaling cascade. The intramembranous phenomena that occur independently of the contribution of other organelles upon tumoral GnRH receptor engagement include (i) activation of phosphotyrosine phosphatase and loss of phosphotyrosine from the endogenous membrane protein and (ii) phosphoinositide and perhaps sphingomyelin cleavage producing lipid-originated second messengers. GnRH has also been demonstrated to increase Fas ligand expression within plasma membrane, which is known to promote apoptotic cell death through attack on Fas-positive cells within tumors. The Fas-Fas ligand complex might, at least in part, account for the antiproliferative action of the hormone. An understanding of the relationship between the extracellular (hormonal) stimuli that leads to cell death and the intracellular events regulating growth arrest on GnRH action may fundamentally help clarify the therapeutic approach to all hormone-dependent carcinomas that respond to stimuli that lead to apoptosis. In this chapter, we review the recent literature and the results of our studies on GnRH-induced membrane events and summarize what is currently known about this promising antiproliferative function.

Apoptosis↗

PubMed2000

Postoperative vesicourethral function after ultrasonic surgical aspirator-assisted surgery of gynecologic malignancies.

OBJECTIVE: The most concerned complication of radical hysterectomy includes the vesicourethral dysfunction. The use of Cavitron ultrasonic surgical aspirator (CUSA) may preserve the blood supply to the urinary tract even during the surgical procedure, prompting us to evaluate the advantage of using the CUSA with the complication. STUDY DESIGN: We analyzed medical profiles of a total of 275 patients with pelvic lymphnode dissection (137 subjects with radical hysterectomy and 138 with modified radical hysterectomy). RESULTS: The use of CUSA in radical (formal or extended) hysterectomy reduced the period for the residual urine to become <50 ml in cases of advanced stages equal and over Ib of uterine cervical cancers. CONCLUSION: The CUSA may be more effective in the prevention of radical hysterectomy for its major complication, vesicourethral dysfunction. The CUSA-assisted surgery may be applicable, primarily, for advanced uterine cancer.

Female↗

PubMed2000

Postpartum microangiopathic hemolytic anemia: cases of successful and dismal outcome assisted with plasma therapy.

Microangiopathic thrombosis, thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS), seem to occur with certain stresses, including pregnancy. This report documents the clinical outcome with or without plasma therapy and dismal outcomes of two cases with postpartum microangiopathic thrombosis. One carried a pregnancy to successful cesarean delivery and suffered from postpartum TTP/HUS followed by plasma therapy-assisted recovery. Another developed postpartum TTP/HUS and was complicated with subarachnoid hemorrhage. Submission to plasma therapy should always be considered in a woman with postpartum microangiopathic thrombosis.

Adult↗

PubMed2000

Enhancement of nitric oxide generation by low frequency electromagnetic field.

Oxidative stress is implicated in the intracellular signal transduction pathways for nitric oxide synthase (NOS) induction. The electromagnetic field (EMF) is believed to increase the free radical lifespan [S. Roy, Y. Noda, V. Eckert, M.G. Traber, A. Mori, R. Liburdy, L. Packer, The phorbol 12-myristate 13-acetate (PMA)-induced oxidative burst in rat peritoneal neutrophils is increased by a 0.1 mT (60 Hz) magnetic field, FEBS Lett. 376 (1995) 164-6; F.S. Prato, M. Kavaliers, J.J. Carson, Behavioural evidence that magnetic field effects in the land snail, Cepaea nemoralis, might not depend on magnetite or induced electric currents, Bioelectromagnetics 17 (1996) 123-30; A.L. Hulbert, J. Metcalfe, R. Hesketh, Biological response to electromagnetic fields, FASEB 12 (1998) 395-420]. We tested the effects of EMF on endotoxin induced nitric oxide (NO) generation in vivo. Male BALB/C mice were injected with lipopolysaccharide (LPS) intraperitoneously (i.p.), followed by the exposure to EMF (0.1 mT, 60 Hz). Five hours and 30 min after the LPS administration, mice were administered with a NO spin trap, ferrous N-methyl-D-glucaminedithiocarbamate (MGD-Fe). Thirty minutes later, mice were sacrificed, and their livers were removed. The results were compared to three control groups: group A (LPS (-) EMF(-)); group B (LPS(-) EMF(+)); group C (LPS(+) EMF(-)). The ESR spectra of obtained livers were examined at room temperature. Three-line spectra of NO adducts were observed in the livers of all groups. In groups A and B very weak signals were observed, but in groups C and D strong spectra were observed. The signal intensity of the NO adducts in Group D was also significantly stronger than that in Group C. EMF itself did not induce NO generation, however, it enhanced LPS induced NO generation in vivo.

Journal Article↗

PubMed2000

Regulation of ANP-stimulated guanylate cyclase in the presence of Mn2+ in rat lung membranes.

The catalytic activity of guanylate cyclase (GCase) coupled to atrial natriuretic peptide (ANP) receptor depends on the metal co-factor, Mn2+ or Mg2+. ATP synergistically stimulates the ANP-stimulated GCase in the presence of Mg2+. We have now shown the ATP regulation of the ANP-stimulated GCase in the presence of Mn2+ in rat lung membranes. ANP stimulated the GCase 2.1-fold compared to the control. ATP enhanced both the basal (basal-GCase) and the ANP-stimulated GCase maximally 1.7- and 2.3- fold compared to the control, respectively, at a concentration of 0.1 mM. The stimulation by ATP was smaller in the presence of Mn2+ than in the presence of Mg2+. The addition of inorganic phosphate to the reaction mixture altered the GCase activities in the presence of Mn2+ with or without ANP and/or ATP. In the presence of 10 mM phosphate, ATP dose-dependently stimulated the basal GCase 5-fold compared to the control at a concentration of 1 mM and augmented the ANP-stimulated GCase, which was 4.2-fold compared to the basal-GCase, 5.5-fold compared to the control at a concentration of 0.5 mM. Protein phosphatase inhibitors, okadaic acid (100 nM), H8 (1 microM) and staurosporin (1 microM), did not alter the activity. Orthovanadate (1 mM), an inorganic phosphate analogue, significantly stimulated both the basal-GCase and the ANP-stimulated GCase, which were inhibited by ATP. It was assumed that phosphate and orthovanadate might interact with the GCase to regulate the activity in the opposite manner. This was the first report that inorganic phosphate and orthovanadate affected the ATP-regulation of the ANP-stimulated GCase in the presence of Mn2+.

Adenosine Triphosphate↗

PubMed2000

IgE antibody to fish gelatin (type I collagen) in patients with fish allergy.

BACKGROUND: Most children with anaphylaxis to measles, mumps, and rubella vaccines had shown sensitivity to bovine gelatin that was included in the vaccines. Recently, it was found that bovine type I collagen, which is the main content in the gelatin, is a major allergen in bovine gelatin allergy. Fish meat and skin also contain type I collagen. OBJECTIVE: The present study was designed to investigate IgE antibody to fish gelatin in children with fish allergy. METHODS: Serum samples were taken from patients in 3 groups: (1) 10 patients with fish allergy and specific IgE to fish meat; (2) two patients with allergies to both fish meat and bovine gelatin and specific IgE to fish meat and bovine gelatin; and (3) 15 patients with atopic dermatitis and specific IgE to fish meat. Various fish gelatins (type I collagen) were prepared from fish skin. IgE antibody to fish gelatin was analyzed by using ELISA and immunoblotting. RESULTS: Of 10 patients with fish allergy, 3 had specific IgE to fish gelatin. Of two patients with fish allergy and bovine gelatin allergy, all had specific IgE to fish gelatin. Of 15 patients with atopic dermatitis and specific IgE to fish meat, 5 had specific IgE to fish gelatin. Furthermore, IgE from pooled serum of the patients reacted with both the alpha1 and alpha2 chains of fish type I collagen in immunoblots. There is cross-reactivity among gelatins from various fishes, but there is little cross-reactivity between fish and bovine gelatins. CONCLUSION: Some fish-sensitive patients possessed IgE antibody to fish gelatin. Fish gelatin (type I collagen) might be an allergen in subjects with fish allergy.

Adolescent↗

PubMed2000

Gonadotropin-releasing hormone analog repairs reduced endometrial cell apoptosis in endometriosis in vitro.

OBJECTIVE: Impaired sensitivity of endometrial tissue to spontaneous apoptosis in women with endometriosis contributes to the abnormal implantation and growth of endometrium at ectopic sites. Our purpose was to examine the effect of gonadotropin-releasing hormone analog, widely used in the treatment of endometriosis, on the reduced rate of endometrial apoptosis in endometriosis. STUDY DESIGN: Paired ectopic and eutopic endometrial tissue specimens were obtained from 13 patients with endometriosis, and control samples were taken from 8 patients with uterine myoma. Apoptotic cell death was assessed biochemically and morphologically with an enzyme-linked immunoassay and Hoechst No. 33342 staining of deoxyribonucleic acid fragment, respectively. RESULTS: Spontaneous apoptosis was significantly lower in ectopic and eutopic endometrial tissue from patients with endometriosis (0.22 +/- 0.082 in absorbance) than in endometrial tissue from control subjects (0.52 +/- 0.483)(P < 0.001). Incubation with a gonadotropin-releasing hormone analog (1 micromol/L) increased the apoptotic rate of endometrial cells from patients with endometriosis to 0.56 +/- 0.501 (P <.001). The effect of this gonadotropin-releasing hormone revealed a dose dependency; a half-maximal effect occurred with 10 nmol/L; however, the control endometrium was not affected. CONCLUSION: Exposure to gonadotropin-releasing hormone results in changes of the sensitivity of endometriotic endometrium to spontaneous apoptosis; these changes in sensitivity may, in turn, release endometrial cells from resistance to apoptosis and result in reduced survival and growth. This phenomenon could, at least in part, account for the therapeutic action of gonadotropin-releasing hormone analog on endometriosis.

Apoptosis↗