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Biomedical subjects

K Nakada

Publications and source records attributed to K Nakada.

At least 109 records · Page 6Linked to original sources

Amelioration of intestinal dysmotility and stasis by octreotide early after small-bowel autotransplantation in dogs.

BACKGROUND: Intestinal dysmotility and stasis after intestinal transplantation are considered to promote bacterial overgrowth and translocation. Two prokinetic agents, KW5139 (13-leu-motilin) and the somatostatin analogue octreotide acetate, were studied to determine whether they can ameliorate intestinal dysmotility during the early postoperative period. MATERIALS AND METHODS: Motility was recorded by multiple extraluminal strain-gauge transducers in 6 dogs on postoperative days 1, 3, 7, and 14. A barium meal study was performed with a separate group of 8 dogs on postoperative days 3 and 7. RESULTS: The agent KW5139 induced brief, weak contractions in the graft and had little effect on the dilated bowel; however, octreotide induced motor activity that propelled accumulated intestinal contents into the colon and reduced dilation of the transplanted bowel. CONCLUSION: Octreotide, but not KW5139, ameliorates intestinal dysmotility associated with bowel autotransplantation during the early postoperative period. Short-term administration of octreotide may be useful for the treatment of dysmotility following intestinal transplantation.

Animals↗

Enzyme activities related to glucose metabolism in Babesia microti and Babesia rodhaini.

A comparative study was carried out on the glucose metabolism in Babesia microti (BM) and Babesia rodhaini (BR) by analyzing the enzyme activities. The lactate dehydrogenase (LDH) activity in BM showed significantly lower values than that in BR, whereas citrate synthase (CS) and malate dehydrogenase (MDH) activities were remarkably higher in BM. In addition, pyruvate dehydrogenase (PDH), isocitrate dehydrogenase (ICDH), alpha-ketoglutarate dehydrogenase (KGDH), and succinate dehydrogenase (SDH) activities also tended to be higher in BM. Then, the change of enzyme activities related to the proliferation of parasites was examined. In BM infected mice, the parasitemia increased from day 15 to day 19 after inoculation (a.i.). While BM showed decrease of G6PD and LDH activities at day 19 a.i., it showed remarkably increased activities in CS and MDH (368 and 8,842 nmol/min.mg protein, respectively). In addition, PDH, ICDH, KGDH, and SDH activities also tended to increase from day 15 to 19 a.i. In BR infected mice, parasitemia increased from day 9 to day 12 a.i. LDH activity showed a considerable increase at day 12 a.i. (12,920 IU/mg.protein). Although CS and MDH activities also showed a slight increase at day 12 a.i., the activities of PDH, ICDH, KGDH and SDH didn't change from day 9 to 12 a.i. Since these changes observed in the enzyme activities of BM and BR seemed to be correlated with their proliferation, it was suggested that BM and BR depended on aerobic and anaerobic pathways, respectively, for their glucose metabolism.

Animals↗

A short term in vitro cultivation of Babesia rodhaini and Babesia microti.

In vitro cultivation of Babesia rodhaini (BR) and Babesia microti (BM) was attempted. When RPMI1640 was supplemented with 30 or 40% of non-treated fetal bovine serum (FBS), the gas mixture of 3% CO2-8% O2 best supported the growth of both parasites. Under this optimized condition, the percent parasitized erythrocytes peaked to approximately 4- and 2-times initial values for Br and BM, respectively. The cultivated parasites retained the infectivity to the host mice. BM showed the characteristic feature of division during cultivation. However, the lots of FBS will have to be taken into consideration, since the FBS lots were shown to give large varieties to the results. Selection of the appropriate FBS lot may yield the better growth of these protozoa.

Animals↗

[Effect of gastrectomy on gallbladder motility: an experimental study].

Gallstone formation is frequently seen following gastric surgery. Since dysmotility and bile stasis of the gallbladder is considered as an important factor in the pathogenesis of gallstone formation, altered gallbladder motility due to gastric surgery may have a role in the development of post-gastrectomy gallstone formation. To test this hypothesis, the effect of distal partial gastrectomy on gallbladder motility were studied. Gastroduodenal and gallbladder contractions were recorded by chronically implanted strain gauge transducers under conscious state. Gallbladder volume changes were monitored using chronically indwelling gallbladder catheter. Fasted and fed motility were studied in control (n = 5) and gastrectomized (n = 3) dogs. Plasma concentration of putative hormone CCK was measured. Effect of CCK-OP and motilin on gallbladder emptying were also studied. In fasted state, gallbladder volume was periodically decreased synchronous with phase 3 of interdigestive migrating contractions (IMC) in the gastroduodenum in both group of dogs. The correlation between gastric and gallbladder contractions was preserved even following distal partial gastrectomy, though the frequency of phasic contractions during phase 3 of IMC was decreased in the gastrectomized dogs. Postprandial gallbladder emptying tend to decreased in the gastrectomized dogs, while there were no difference in the postprandial plasma CCK concentrations and CCK-OP induced gallbladder emptying between groups. Digestive period was shortened in the gastrectomized dogs, which resulted in early gallbladder refilling and prolonged interdigestive period. Decreased frequency of gallbladder phasic contractions during IMC and prolonged interdigestive period could cause bile stasis in the gallbladder, which may, in part, explain post-gastrectomy gallbladder formation.

Animals↗

[Chest pain in a patient after median sternotomy].

A 62-year-old woman presented with a 1-year history of painful operative scar following median sternotomy performed for coronary artery bypass grafting at another hospital shortly after myocardial infarction. She had a 5-year history of diabetes mellitus, which had been controlled with diet therapy. There were no abnormalities in electrocardiographic or cardiac function. She complained of burning pain and marked tenderness bilaterally in the parasternal region. There were no abnormal laboratory findings. No fractures were detected in the ribs or sternum radiographically. Her chest pain was not alleviated by analgesics including nonsteroidal anti-inflammatory agents or tricyclic antidepressants. Neither local anesthesia nor thoracic epidural anesthesia was effective in eliminating her pain. Slight relief was obtained by heating with infrared radiation, but the duration of pain relief was very short. This patient's findings indicate that painful operative scar should be considered as a potentially serious complication of surgery requiring median sternotomy.

Chest Pain↗

[Ultrasonography of pediatric right lower abdominal pain: correlation with clinical and pathological results].

Right lower abdominal pain is a common problem in the pediatric population. Ultrasonography (US) is a well-accepted imaging modality in the clinical management of this problem. One hundred and six consecutive pediatric patients with right lower abdominal pain were prospectively evaluated. There were 54 boys and 52 girls, with ages ranging from 3 to 15 years (mean: 9.9 years). Final diagnoses were established based on pathological findings or clinical follow-up. US had sensitivity of 90%, specificity of 98%, and accuracy of 94% in the diagnosis of acute appendicitis. Among all true negative cases (n = 55), there was a variety of US findings other than appendiceal abnormality in 21 cases including intestinal and/or mesenteric (n = 19), gallbladder (n = 1), and ovarian (n = 1) abnormalities. All 21 cases were managed medically without complication. We conclude that US of pediatric right lower abdominal pain is a reliable imaging modality not only for the diagnosis of surgical cases but for eliminating the unexpected surgical intervention.

Abdominal Pain↗

[Quantitative image feature analysis of echographic textures using the normalized first moment of the power spectra: comparison of normal thyroid with chronic thyroiditis].

In order to evaluate the coarseness of echographic textures objectively, ultrasonic B-mode data from the thyroid glands in 10 normal subjects and 10 patients with chronic thyroiditis were digitized. The normalized first moment of the power spectra in the digitized matrix data that were obtained was calculated by computer processing of a Fourier transformation algorithm. On phantom study, when the location of the region to be analyzed or the gray scale level of the images was changed, the normalized first moment of the power spectra in the low frequency region of less than 1.0 cycle/mm varied significantly, and noise components in the high frequency region of more than 2.5 cycles/mm exceeded the signal components. Thus we attempted to calculate the normalized first moment of the power spectra from 1.0 to 2.5 cycles/mm in human thyroid glands. The values of the normalized first moment of the power spectra in the thyroid glands with normal (n = 20) and chronic thyroiditis (n = 20) were 0.989 +/- 0.036 and 1.065 +/- 0.063, respectively. These values were significantly different between the two groups (p < 0.01). It is concluded that the normalized first moment of the power spectra calculated within the limited frequency is useful in characterizing the echographic texture of chronic thyroiditis.

Chronic Disease↗

[Imaging of infectious and inflammatory foci using 111In-DTPA-IgG].

We performed radionuclide scanning after intravenous administration of 80 MBq of 111In-labeled non-specific polyclonal human immunoglobulin G (111In-DTPA-IgG). Serial scintigrams were acquired at 6, 24, 48, and 72 hr after injection in 10 patients suspected of having inflammation and/or infection. In 5 patients, the results of scintigraphy were verified with intraoperative cultures or biopsy. The values were as follow: sensitivity: 100% (4/4); specificity 50% (3/6); accuracy: 70% (7/10); positive predictive value: 57.1% (4/7); and negative predictive value: 100% (3/3). The results indicate that 111In-DTPA-IgG scintigraphy is certainly a promising method for the detection of inflammation and/or infection.

Adult↗

Efficacy of recombinant human granulocyte-macrophage colony-stimulating factor for chemotherapy-induced leukopenia in patients with non-small-cell lung cancer.

To assess the feasibility and efficacy of rhGM-CSF in ameliorating chemotherapy-induced leukopenia in patients with advanced non-small-cell lung cancer, we conducted a double-blind placebo controlled phase III study in a multicenter setting. Patients were eligible if they had cytologically or histologically proven cancer, no prior chemotherapy, stage IIIB or IV disease, an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2, an age of less than 76 years, and no symptomatic brain metastasis, disseminated bone metastasis, or previous vertebral/pelvic irradiation. The chemotherapy regimen consisted of mitomycin given at 8 mg/m2 on day 1, cisplatin given at 100 mg/m2 on day 1, and vindesine given at 3 mg/m2 i.v. on days 1 and 8 (MVP). If the granulocyte nadir count recorded after the first cycle of MVP was less than 1,000/mm3, patients were randomly assigned to receive recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) or placebo during the second cycle of MVP. The dose of rhGM-CSF was 125 micrograms/m2 given daily s.c. for 14 consecutive days starting on day 2. Of the 52 patients enrolled, 45 were evaluable. The nadir of granulocytes was significantly lower in the placebo group (P = 0.007). The period during which the granulocyte count was less than 1,000/mm3 was significantly longer in the placebo group (median, 6 vs 10 days; P = 0.04). The incidence of adverse effects related to rhGM-CSF, such as fever (> or = 38 degrees C) and skin rash, was significantly higher in the rhGM-CSF group (P = 0.011). The rate of response to chemotherapy did not significantly differ between the two groups. In conclusion, rhGM-CSF reduced the duration of chemotherapy-induced granulocytopenia. The clinical usefulness of this agent may be deminished because of the adverse effects encountered when it is used in combination with a moderately myelotoxic chemotherapy regimen.

Adult↗

Autoradiographic analysis of [14C]deoxy-D-glucose in thyroid cancer xenografts: a comparative study with pathologic correlation.

An experimental model of thyroid cancer was prepared for evaluating the accumulation of [14C]deoxy-D-glucose ([14C]DG) in thyroid cancer xenografts (AC2). A continuous cell line established from a biopsy specimen of a metastatic thyroid carcinoma possessed the ability to synthesize the cellular protein without increase in cell division after adding bovine TSH in vitro. The histological sections of the xenografts resected from the 131I treated nude mice mainly consisted of structures showing follicular and trabecular growth. Immunohistochemically the cytoplasm of the tumor cells was positive for human thyroglobulin(hTg). These observations provide strong evidence that the AC2 cell originates in the thyroid follicular epithelium. By comparing autoradiographic accumulation patterns of [14C]DG and histopathological examinations, it was found that the uptake of [14C]DG was higher in the granulation tissues surrounding necrosis than in viable tumor cells of trabeculary growing and follicle forming tissues. It is suggested that the degree of [14C]DG content reflects not only tumor cell viability and proliferation but also the inflammatory and degenerative reaction accompanying tumor cell growth.

Animals↗

Characterization of platelet activity in neuroblastoma.

A study was conducted to characterize the platelet aggregation induced by neuroblastoma tissue to investigate the mechanism of hypercoagulability in patients with neuroblastoma. The patients whose tumor tissues were examined had been shown clinically to have enhanced platelet activity. Platelet aggregation induced by neuroblastoma tissue extract was compared with that of other pediatric tumors. The effects of pretreatment with an antithrombin agent and prostacyclin (PGI2) on the platelet aggregation induced by tumor tissue extracts were also evaluated. Tissue extracts of 12 of 15 neuroblastomas, 3 of 3 Wilms' tumors, and 1 pheochromocytoma were demonstrated to have an activity that potentiated platelet aggregation in vitro. The platelet aggregation induced by tissue extracts of neuroblastomas and other tumor tissues was suppressed almost completely by pretreatment with a PGI2 analogue. The aggregation induced by neuroblastomas and the pheochromocytoma was also suppressed by pretreatment with an antithrombin agent, argatroban, whereas the aggregation induced by Wilms' tumors was not suppressed by this agent. These results suggest that (1) malignant tumors in children also have some chemical substances that sensitize platelet activity, such as those in adult cancers, and (2) thrombin is one of the mediators stimulating platelet aggregation in cases of neuroblastoma, although it is unlikely to be a contributing factor in other pediatric malignancies such as Wilms' tumor.

Antithrombins↗

A study of dose escalation of teniposide (VM-26) plus cisplatin (CDDP) with recombinant human granulocyte colony-stimulating factor (rhG-CSF) in patients with advanced small cell lung cancer.

A dose escalation study of teniposide (VM-26) plus cisplatin (CDDP) was carried out using recombinant human granulocyte colony-stimulating factor (rhG-CSF) in 46 previously untreated patients with advanced small cell lung cancer (SCLC). The dose of CDDP was 80 mg/m2/day intravenously (i.v.) (day 1) and VM-26 was escalated from 60 mg/m2/day to 80, 100 and 120 mg/m2/day i.v. x 5 days for four cycles. The dose of rhG-CSF was 90 micrograms/m2/day subcutaneously for 13 days. The feasibility of the regimen at the starting dose level of VM-26 with or without rhG-CSF was initially examined in 10 patients chosen through random allocation. WHO grade 4 neutropenia was observed in 17% (three out of 18 courses) of patients in the rhG-CSF group and in 63% (12 out of 19 courses) of the control group (P < 0.01). The number of patients with febrile episodes (> 38 degrees C) over the four courses of chemotherapy was 1 in the rhG-CSF group and 4 in the control group. According to these results, all 36 patients received rhG-CSF in the dose escalation stage. The incidence of WHO grade 4 neutropenia at the dose levels of 60, 80, 100 and 120 mg/m2/day of VM-26 was 66, 57, 76 and 85%, respectively (P > 0.1). The incidence of grade 4 thrombocytopenia was 19, 31, 18 and 46%, respectively (P > 0.1). The overall response rate was 100% in patients with limited stage SCLC and 83% in patients with extensive stage SCLC. The actual administered VM-26 dose per week at the dose level of 100 mg/m2/day was 1.6-fold higher than the planned starting dose (60 mg/m2/day) per week. At the dose level of 120 mg/m2/day, 50% of patients developed WHO grade 4 leucopenia, which lasted longer than 1 week and 67% of the patients had WHO grade 3 or 4 diarrhoea. At this same dose, all patients had at least one febrile episode (> 38 degrees C), and 1 patient died of cerebral bleeding with severe thrombocytopenia. The median survival time of all patients was 451 days (411 days, extensive disease; 497 days, limited disease). VM-26 plus CDDP with rhG-CSF was active in previously untreated patients with SCLC. The recommended dose of VM-26 in combination with CDDP for a phase II study is 100 mg/m2/day for 5 days with rhG-CSF support.

Adult↗

Sperm-egg fusion in the sea urchin is blocked in Mg(2+)-free seawater.

Magnesium ions as well as calcium ions are required for successful fertilisation in sea urchins. In the absence of Mg2+ spermatozoa attached to the egg plasma membrane, their acrosomal processes passing through the vitelline envelope, but could not enter the egg cytoplasm (Sano et al., Dev. Growth Differ. 22, 531-41, 1980). Such an individual spermatozoon was observed microscopically to resume entry into the egg immediately after the addition of a sufficient amount of Mg2+ to the surrounding medium. Neither any change in membrane potential nor an increase in intracellular Ca2+ concentration of the egg was observed after insemination in the absence of Mg2+, although both could be observed after the addition of Mg2+. The sperm heads did not show fluorescence when attached to the surface of an egg previously microinjected with mithramycin A in Mg-free seawater, indicating that there was no connection between the sperm and the egg. Therefore, occurrence of fertilisation potential must be a post-fusional event. These results suggest that Mg2+ are indispensable for fusion between the sperm acrosomal membrane and the egg plasma membrane.

Animals↗

[Clinical usefulness of the combined empirical therapy with flomoxef and fosfomycin for intractable respiratory tract infections. With a background of increasing MRSA incidence].

We conducted a multicenter trial to determine the clinical usefulness of the combined therapy with flomoxef (FMOX) and fosfomycin (FOM) (FF therapy) as an empirical therapy in the treatment of intractable respiratory tract infections, because FF therapy has clinically been proved to be very useful for the treatment of severe infections including MRSA infections. The overall efficacy rate of FF therapy was 69.2%. The efficacy rate for "pneumonia/lung abscess," which occupy the largest portions of respiratory tract infections, was 70.0%, showing a statistically significant difference from the efficacy rate for FMOX alone (56.7%) found in a previous study (P = 0.09 by chi-squared test). Although MRSA was eradicated in only 3 cases (37.5%) including superinfection cases, of 8 patients, from whom MRSA had been isolated as causative organisms, none of our patients were superinfected with MRSA. Thus it has been concluded that FF therapy is clinically very useful when used as an empirical therapy in the treatment of respiratory tract infections.

Aged↗