Biomedical subjects

J Yokoyama

Publications and source records attributed to J Yokoyama.

At least 19 recordsLinked to original sources

PubMed1995

Treatment combined with bone marrow transplantation for advanced neuroblastoma: an analysis of patients who were pretreated intensively with the protocol of the Study Group of Japan.

One hundred and ten patients with advanced neuroblastoma were treated with the protocol of the Study Group of Japan between January 1985 and March 1991. Patients received six cyclic courses of regimen A1, consisting of cyclophosphamide (1,200 mg/m2), vincristine (1.5 mg/m2), tetrahydropyranyl adriamycin (40 mg/m2), and cisplatin (90 mg/m2). Primary tumors and regional lymph node metastases were removed some time during the first six cycles of regimen A1. After six cycles of A1, the patients were divided into three groups. Patients in group 1 received alternating treatment with regimen B (cyclophosphamide and ACNU) and intensified A1, and those in group 2 were treated with alternating administration of regimen C (cyclophosphamide and DTIC) and intensified A1. Patients in group 3 were treated with supralethal therapy and bone marrow transplantation (BMT). Event-free survival rates at five years were 38.8% in the chemotherapy group (groups 1 and 2) and 50.0% in the transplant group (group 3). Because of the study design that was not in truly randomized fashion and because of the small number of patients in each risk group, it is indicated, though not concluded, that the transplant group had a better prognosis than the chemotherapy group in the cases with stage III disease or with amplified N-myc oncogene, based on the statistical calculations. Differences in survival rates for patients who underwent BMT when complete remission (CR) was achieved and for those who achieved CR but who did not undergo marrow transplant were statistically insignificant. BMT-related death occurred in 3 of 31 cases (9.7%) undergoing marrow transplant, and the causes of the death included hemorrhagic pneumonia, myocardial disturbance and hemorrhagic uremia.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1995

Outcomes of ileocolic conduit for biliary drainage in infants with biliary atresia; comparison with Roux-en-Y type reconstruction.

This study was undertaken to define the role of an ileocolic conduit that was devised as anti-reflux procedure in comparative study with Roux-en-Y type reconstruction in infants with biliary atresia treated at a single institution. The ileocolic conduit (IC) consisted of 30 cm of distal ileum anastomosed to the portahepatis and a 10-cm segment of ascending colon vented through the abdominal wall, which was later anastomosed to the second portion of the duodenum. In the Roux-en-Y type reconstruction (RY), 40 to 60 cm of jejunum was used for the hepatic limb. Twenty-three infants in group IC and 16 infants in group RY were entered in this study. Mean ages at definitive surgery were 65.3 +/- 23.1 days for group IC and 65.0 +/- 19.5 days for group RY. The two groups were compared for the postoperative outcomes in terms of bile excretion, incidence of cholangitis, esophageal varices, survival rate, and the effects on physical development. The follow-up ranged from 4 to 15 years. Bile excretion was obtained in all infants in both groups. Twenty infants (87.0%) in group IC and 10 infants (62.5%) in group RY became anicteric. Cholangitis occurred in 60.9% of group IC, compared with 83.3% for group RY, in which 6 infants required revision to complete diversion of Roux-en-Y limb (Suruga II). There was the same occurrence rate of esophageal varices for both groups. However, the varices tended to develop later in group IC (53.0 +/- 18.4 months) than in group RY (12.7 +/- 6.0 months) (P < .02).(ABSTRACT TRUNCATED AT 250 WORDS)

Biliary Atresia↗

PubMed1995

The role of surgery in advanced neuroblastoma.

Recently we performed multi-modal therapy including chemotherapy with bone marrow transplantation (BMT), surgery, and local irradiation in the treatment of advanced neuroblastoma. As a result, all Stage III patients survived, and 4 out of 8 Stage IV patients who underwent our original systemic gross complete resection achieved long-term survival, 4y8m, 5y8m, 5y6m and 5y5m, respectively. Long-term survival patients were treated by local irradiation, brain surgery and intensive induction chemotherapy before primary site operation, and when resolution of distant metastases was obtained, the primary site was resected completely, followed by postoperative supralethal chemotherapy with BMT. The purpose of this report is to elucidate the role of surgery in advanced neuroblastoma based on our clinical results.

Bone Marrow Transplantation↗

PubMed1994

Inhibition of the growth of cariogenic bacteria in vitro by plant flavanones.

Phytoalexins, defensive compounds produced by plants against microbial infections, were purified from Sophora exigua (Leguminosae) and their growth inhibitory effects on oral cariogenic bacteria were determined in vitro. Among three isolated compounds, 5,7,2',4'-tetrahydroxy-8-lavandulylflavanone completely inhibited the growth of oral bacteria including primary cariogenic mutans streptococci, other oral streptococci, actinomycetes, and lactobacilli, at concentrations of 1.56 to 6.25 micrograms/ml.

Actinomyces↗

PubMed1994

Long-term results of surgical treatment in infants with total colonic aganglionosis.

The authors describe the long-term results of the surgical treatment of total colonic aganglionosis (TCA) in nine boys who have been treated since 1975. The principal operative procedure was endorectal pull-through of the ganglionic ileum, with the aganglionic colon as an onlay patch. The procedure was employed in five infants, using the right or left colon. Ileorectostomy with an onlay patch was used in two patients; ileoanostomy without the patch was used in two. The distal end of the pulled-through ileum was, on average, 39 cm from the ileocecal junction. The average follow-up period was 11.0 years. Diarrhea and distension were temporary after the pull-through, and all patients ultimately tolerated normal feeding. Considering the variation in operative techniques, we were unable to demonstrate any advantage of one procedure over another. Z scores for height and weight at the last follow-up examination correlated with the weight gain before the definitive surgery and inversely correlated with the length of resected distal ileum at the time of operation.

Anal Canal↗

PubMed1994

Recto-vagino-vestibuloplasty using a vagino-colonic flap with double colonic implantation for rectocloacal fistula.

This technique was devised to obtain a good cosmetic appearance of the perineum and a functional neovagina, without any need for a dilator, by using a vaginocolonic flap marsupialized to the perineum and by creating a vestibule with noncornifying squamous epithelium. The technique was used to treat a 2 year old girl who had a single small orifice in the upper part of a featureless perineum, with a high-confluence rectocloacal fistula between a short urethra and double vagina, which was separated by a septum. A long inverted U-shaped flap at the posterior wall of the vagina was reversed to become the anterior wall of the distal vagina. The urogenital sinus (UGS) was preserved to serve as the urethra. The colon distal to the colostomy was divided into two loops; a segment of the distal loop was opened and trimmed to form a flap, and served as the posterior wall of the distal vagina. The proximal segment was pulled down to become the rectum. To construct the vestibule, a vertical midline incision was made from the fused labia minora to the perineum, cutting back the UGS. The anterior wall of the vagina, which was pulled through just behind the UGS, was divided vertically and sutured around the opened UGS and the suitably prepared labia minora. The posterior wall, which consisted of the colonic flap, was sutured to the incised perineal skin, creating a posterior commissure. At present, 2 1/2 years after the repair, the patient is dry between completely continent urinations and has little vaginal discharge.(ABSTRACT TRUNCATED AT 250 WORDS)

Child, Preschool↗

PubMed1994

What is the benefit of aggressive chemotherapy for advanced neuroblastoma with N-myc amplification? A report from the Japanese Study Group for the Treatment of Advanced Neuroblastoma.

In 1985, a nationwide single protocol (cyclophosphamide, vincristine, tetrahydropyranyl Adriamycin, and cisplatin) for the treatment of advanced neuroblastoma was begun in Japan and was found to significantly increase the 3-year survival rate--to 70% for stage III, and to 45% for stage IV. In this study, the authors investigated the efficacy of this protocol for advanced neuroblastoma with or without N-myc amplification. In 159 of the 233 patients with advanced neuroblastoma treated with this protocol (between January 1985 and March 1993), genomic amplification of N-myc was determined. These 159 patients were divided into two groups according to the number of N-myc copies, ie, those with fewer than 10 copies (105 patients) and those with 10 or more copies (54 patients). The survival curves for the two groups were significantly different. The 5-year survival rate for patients with 10 or more copies was 43.9%; this is surprisingly high in comparison to results of previous studies in which no survivors were expected in cases of advanced neuroblastoma with highly amplified N-myc. Persistent bone marrow suppression was common, but there were no deaths attributable to drug side effects. Five patients with fewer than copies of N-myc amplification died more than 3 years after initial treatment. Three of the five had tumors with an unfavorable Shimada classification, and two had diploid nuclear DNA content. The authors conclude that the protocol resulted in dramatic improvement in the patients with advanced neuroblastoma, even with high N-myc amplification.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1994

Flavanones with potent antibacterial activity against methicillin-resistant Staphylococcus aureus.

With the therapeutic concept of using the defensive ability of plants against microbial infections, phytoalexin, an antimicrobial phytochemical was studied for its ability to inhibit the growth of methicillin-resistant Staphylococcus aureus (MRSA). Extracts from Sophora exigua (Leguminosae) were fractionated by serial chromatography and the anti-MRSA activity of each fraction was determined by the agar-plate method. Among the active isolates, 5,7,2',6'-tetrahydroxy-6-isoprenyl-8-lavandulyl-4'-methox yflavanone (exiguaflavanone D) completely inhibited the growth of all the MRSA strains examined at the concentration of 1.56-6.25 micrograms mL-1, and 5, 2',6'-trihydroxy-8-lavandulyl-7-methoxy-flavanone (exiguaflavanone B) inhibited at a concentration of 50 micrograms mL-1. This former compound is expected to be a phytotherapeutic agent for MRSA infections as an alternative to conventional antibiotics with unwanted side-effects or the appearance of antibiotic-resistant bacteria.

Anti-Bacterial Agents↗

PubMed1994

Three frequency component waveforms of auditory evoked brainstem response in spinocerebellar degeneration.

Under adequate stimulus intensities, the power spectra of normal auditory evoked brainstem responses (ABRs) are composed of three major components: 0-350 Hz, 350-700 Hz and 700-1200 Hz. By means of a digital filter using fast Fourier transform, three ABR waveforms consisting of each frequency component of the power spectrum were obtained. The significance of these three component waveforms in the analysis of ABR abnormality was estimated in 30 patients with spinocerebellar degeneration (SCD). In conventional wave latency analysis, 9 out of 30 patients (30%) had abnormal ABRs, the main abnormality being prolonged interpeak latencies of waves I-III, I-V and the disappearance of wave V. On the other hand, component waveforms were abnormal in 82.5% of the cases. These results suggest that analysis of ABRs by the use of component waveforms is useful for detecting abnormality in the brainstem auditory pathway in SCD patients.

Audiometry, Evoked Response↗

PubMed1994

Phase spectral analysis of auditory brainstem response in cats.

In order to apply the phase spectral analysis of auditory brainstem response (ABR) to the clinical diagnostic test, the phase spectra of ABRs were investigated under adequate stimulus intensity in normal cats and after the destruction of acoustic nerve and brainstem auditory pathways in cats. The results were as follows; i) In normal ABRs, the phase spectra were mainly composed of three frequency components at 0-300 Hz (component A), 300-900 Hz (component B) and 900-1500 Hz (component C). ii) A greater decrease of the component synchrony measure (CSM) occurred if ipsilateral destruction was performed in a peripheral lesion. Lesions of the auditory pathway were followed by a decrease of the CSM of component C in response to contralateral stimulation. These results suggest that the phase spectral analysis of ABRs has significant clinical value in the detection of brainstem lesions.

Acoustic Stimulation↗

PubMed1994