Biomedical subjects
Publications and source records attributed to K Morimoto.
Summaries of first drafts of Environmental Health Criteria (EHC), which were circulated for comments by IPCS in the period of 1991-1992, were presented. EHC drafts on 14 compounds and one methodology were received in this period.
A phase II study of 5'-deoxy-5-fluorouridine (5'-DFUR) tablets for breast cancer was done at 31 institutions in Japan. Forty-five patients were registered and 44 of them were eligible for the study. Of the 40 patients whose results could be evaluated, 11 (28%) responded (four complete responses and seven partial responses). Side effects, such as diarrhea, anorexia, leukocytopenia, and liver dysfunction were observed in 24 of the 44 patients. The side effects were mild and transient. 5'-DFUR is a promising drug for breast cancer treatment, and its tablet form makes chemotherapy easier for the patient.
Pigmented villonodular synovitis (PVNS) is rare in the foot; however, it developed in the subtalar joint extending around the ankle of a 24-year-old man. The diagnosis was made by a combination of clinical findings, most notably the aspiration of the synovial fluid. Magnetic resonance imaging was most useful in showing the extent of the soft-tissue mass before surgery. Low-signal intensity of the mass, featured on both T1- and T2-weighted images, was suggestive of PVNS.
Twin gestations are responsible for a disproportionate amount of perinatal mortality and morbidity. Such gestations may impose greater demands on maternal and child physiologic systems than singleton pregnancies. The most common antenatal complications were preterm labor. The clinical record of myelomeningocele infant presenting with overt hydrocephalus in utero at 27 weeks of twin gestation and operated miniature Ommaya's reservoir placement early after birth and intentional delayed back closure for myelomeningocele was reported. Although perinatal neurosurgical care for one fetal hydrocephalus on twin gestation is clearly advantageous, it alone is relatively ineffective in reducing the incidence of the complication, preterm labor.
Six clinically and patho-histologically proven cases of chondroblastoma were studied with electron microscopic and immunohistochemical methods. The tumor tissues of chondroblastoma exhibited biphasic pattern i.e., chondroid and cellular area. In the chondroid area, small and round tumor cells contained many filaments in the cytoplasm and small processes in the cell wall. Many glycogen granules were present in the tumor cells in some cases. Intercellular matrix was immunohistochemically positive for S-100 protein and showed fine collagen fibers were very similar to those of articular and epiphysial cartilage. Many portions of mitochondria, cell wall and matrix of chondroblastoma tissue clearly exhibited calcification but were not definitely ossification. In the cellular area, tumor cells were composed of small immature mesenchymal and clear large degenerated tumor cells, histiocytes with lysosomes and osteoclast-like multinuclear giant cells. Immunohistochemical studies in the cellular area revealed that there were many tumor cells positive for lysozyme, alpha 1-antitrypsin and alpha 1-antichymotrypsin. In the transitional zone between chondroid and cellular area, degenerated tumor cells were found. The chondroblastoma was composed of chondroid and histiocytic areas which were very similar to those of chondromyxoid fibroma. The present study appears to demonstrate that chondroblastoma originates from a mixture of chondrocytic and histiocytic tumor cells but not from articular and epiphysial cartilage.
The pharmacokinetics and clinical efficacy of levofloxacin (LVFX, DR-3355), an optically pure S(-)-enantiomer of ofloxacin, were studied in patients after surgery. In the pharmacokinetic study, 4 patients undergoing bile drainage were given 2 100-mg tablets by mouth. Peak levels of LVFX were from 2.22 to 4.02 micrograms/ml of plasma at 2-4 hours after the oral administration, and from 7.5 to 11.3 micrograms/ml of bile at 2-6 hours. Forty-three patients with surgical infections, including 16 skin and soft-tissue infections and 12 wound infections, were treated with LVFX. Twenty-eight (70%) of the 40 patients whose results could be evaluated had excellent or good results; 42 (93%) of the 45 causative organisms identified were eradicated. An episode of diarrhea with chills and fever occurred in a 38-year-old man. The results suggested that LVFX has satisfactory antimicrobial effects in surgical infections.
We report a case of intrarenal arteriovenous fistula (AVF) with macroscopic hematuria detected after nephrolithotomy performed 25 years previously. The present case, successfully treated by transcatheter embolization with steel coils, is the eighth case of postnephrolithotomy AVF reported in English and Japanese literatures. The necessity of renal arteriography in patients with postoperative massive hematuria is stressed.
A time-reversed gradient echo pulse sequence (PSIF; Siemens), one of the MR imaging methods based on steady-state free precession of excited spins, makes the bile duct quite bright relative to the surrounding tissue. Using this sequence under breath hold combined with a two or three-dimensional data set and maximum intensity projection method provided fair delineation of the dilated bile duct and the site of its obstruction or stricture. Though the clinical experience is limited, this technique is considered to be of value in the non-invasive evaluation of bile duct system in the patient of obstructive jaundice.
A time-reversed gradient echo pulse sequence, one of the MR imaging methods based on steady-state free procession of the excited spins, makes the cerebrospinal fluid (CSF) quite bright relative to the normal brain tissue. Using this sequence combined with a three-dimensional data set and maximum intensity projection method, which provided clear delineation of the spatial distribution of the CSF space in the brain. Though the clinical experience is limited, this technique is considered to be of value in the evaluation of CSF pathology.
In the present study, comparative studies of the effects of competitive and noncompetitive antagonists of NMDA receptors (CPP, CGS19755 and MK-801) on two models of neuronal plasticity, kindling and long-term potentiation (LTP), were performed in rats. Systemic administration of CPP (5, 10 mg/kg), CGS19755 (5, 10 mg/kg) or MK-801 (1, 2 mg/kg) strongly retarded kindling development from the amygdala (AM), in which the early stage of kindled seizures and the growth of afterdischarges (ADs) recorded from the AM were significantly suppressed. After establishment of kindling, however, these compounds only reduced the previously AM-kindled seizure stage without shortening the AD duration. These NMDA receptor antagonists with the same dose sufficient for suppressing AM kindling almost completely blocked LTP of the synaptic component in the hippocampal dentate gyrus following high-frequency trains of the perforant path in urethane-anesthetized rats. These results further support the hypothesis that neuronal plasticity is induced by activation of the NMDA receptor complex and one of the basic neuronal mechanisms underlying kindling may be a long-lasting increase in synaptic transmission.
The in vivo effects of allogeneic granulocytes on the reconstitution of splenic and bone marrow CFUs and CFUc numbers were investigated using irradiated mice. When allogeneic granulocytes were intraperitoneally injected into irradiated BDF1 mice (260 rads), the reconstitution of CFUs in both spleen and bone marrow as well as the hematocrit were enhanced, while the reconstitution of splenic or bone marrow CFUc numbers was transiently suppressed and then enhanced. The magnitude of enhancement was dose-dependent. These results suggest that granulocytes injected into irradiated mice might act as enhancing effectors on the in vivo reconstitution of hemopoietic cells.
Most chemicals are S-dependent and are potent inducers of SCE, but do not produce chromosome-type aberrations in the first metaphases after exposure. Ionizing radiation, which is an S-independent agent, produces chromosome-type aberrations, especially dicentrics and rings, but inefficiently produces chromatid-type aberrations. A series of experiments has been performed to investigate whether cytogenetic damage induced by ionizing radiation (gamma-rays) might be assessed separately from that induced by the alkylating chemical, mitomycin C (MMC), when human lymphocytes were exposed to these 2 agents in combination. Whole-blood cultures of human lymphocytes in G0 phase were exposed to gamma-rays and MMC in combination or separately. Cytogenetic analyses were done for both chromosome aberrations (CA), analyzed in cultures incubated for 56 h without BrdUrd, and sister-chromatid exchanges (SCEs) in cultures incubated for 72 h with BrdUrd. The frequency of chromosome-type aberrations (dicentrics and rings) increased with increasing doses of gamma-rays from 0.5 to 4.0 Gy. The dose-response relationships were the same with or without concomitant treatment with MMC (10(-6) M). Although the SCE frequency increased with increasing doses of MMC, the increase was nearly the same as when cells were treated with both MMC and gamma-rays (2 Gy). There was no interaction between MMC and gamma-rays concerning these 2 endpoints.
To evaluate a role of education to acquire a healthy lifestyle (health education) in achieving a smokeless society, the relationship between attitudes toward the legal right to be free from involuntary smoking in public places, based on human rights, and personal health practices was determined using answers to a questionnaire from 887 randomly-selected citizens of Osaka. The answers were analyzed within four subgroups of respondents divided by smoking status and sex. Among the respondents, three significant relationships of attitude scores to health practices were identified. Within subgroups of female subjects, questionnaire attitude scores decreased as health practice scores increased. Among male non-smokers, those who had high health practice scores also had high attitude scores. Among male smokers, there was no statistical association between health practice scores and attitude scores. Our results demonstrated that attitudes toward the legal right to be free from involuntary smoking among male-nonsmokers were closely related to personal health practices, and implied the effectiveness of health education among this subgroup for the advancement of their legal right to be free from involuntary smoking.
Proteolytic enzyme inhibitors were examined as absorption enhancers for the nasal delivery of vasopressin (AVP) and desmopressin (1-d-8-DAVP) in rats. Aprotinin, soybean trypsin inhibitor, and camostat mesilate were used as enzyme inhibitors. The nasal absorption of AVP and 1-d-8-DAVP was evaluated by measuring its antidiuretic effect. Nasal administration of AVP (0.005 IU/kg) or 1-d-8-DAVP alone (2.5 ng/kg) produced a small antidiuretic effect. Coadministration with aprotinin (1000 and 10000 KIU/kg) or soybean trypsin inhibitor (1.25 and 6.25 mM) did not change the antidiuretic effect. However, coadministration with camostat mesilate (1 to 50 mM) significantly increased the antidiuretic effect and, thus, the nasal absorption of AVP and 1-d-8-DAVP. The activities of aminopeptidase, cathepsin-B, and trypsin in the nasal mucosal tissue of rats were 7 nmol/min/mg protein, 0.7 nmol/min/mg protein, and 4.6 pmol/min/mg protein, respectively. Aprotinin and soybean trypsin inhibitor inhibited only the trypsin activity, whereas camostat mesilate inhibited aminopeptidase and trypsin activities. Aprotinin (MW 6500) and soybean trypsin inhibitor (MW 8000), with relatively high molecular weights, may not permeate into the nasal mucosal tissue. In contrast, camostat mesilate is slowly absorbed (8%/hr) and could inhibit the proteolytic activity in the nasal mucosa, resulting in enhanced nasal absorption of AVP and 1-d-8-DAVP.
The effects of viscous solutions of hyaluronate-sodium of various average molecular weights (MW) on the nasal absorption of vasopressin (AVP) and its analogue, 1-deamino-8-D-arginine vasopressin (1-d-8-DAVP), were examined in rats. Solutions of hyaluronate with MW greater than 3 x 10(5) daltons enhanced the nasal absorption of AVP; solutions of MW 5.5 x 10(4) daltons were not effective. The enhancing effects on the nasal absorption of AVP and 1-d-8-DAVP were dependent on the concentration in the range of 0-1.5% (w/v) hyaluronate (MW 1.4 x 10(6) daltons). The nasal absorption of AVP was increased with this solution at lower pH. Bioavailabilities after nasal administration of AVP and 1-d-8-DAVP in hyaluronate solutions (MW 1.4 x 10(6) and 2 x 10(6) daltons) increased more than 2-and 1.6-fold as compared to nasal administration of AVP and 1-d-8-DAVP in buffer solutions (pH 7.0), respectively. Hyaluronate solution (MW 1.4 x 10(6) daltons) did not affect the ciliary beat frequency of rabbit nasal mucosal membranes in vitro. Therefore, hyaluronate solution may be useful as a vehicle for nasal delivery of AVP and 1-d-8-DAVP.
DNA damage in the forestomach epithelium of male F344 rats was tested by alkaline elution assay following oral administration of 3-tert-butyl-4-hydroxyanisole (3-BHA) and its free metabolites. Although 1% 3-BHA and 0.001% tert-butylhydroquinone (BHQ) caused no detectable DNA damage, a tert-butylquinone (BQ) treated group showed a significantly higher elution rate than the corn oil and 3-BHA group. Dose-dependent induction of DNA damage in forestomach epithelium by 3-BHA metabolites was compared. BQ showed DNA damaging activity from 0.0001% (1 microgram/ml). On the other hand, BHQ showed the activity at greater than 100 times higher concentration than that of BQ. Six other quinones related to the BQ have been synthesized and examined in vivo for their activity in single strand breaks in forestomach epithelium DNA. The order of the DNA damage was not always correlated with the order of the first reduction potentials of the quinones. 2-Benzylthio-5-tert-butyl-p-benzoquinone (BQSBn-2), 2-phenyl-1,4-benzoquinone and 2,5-di-tert-butyl-p-benzoquinone had higher DNA damaging activity than BQ. The effects of ethylacrylate (EA) pretreatment on the DNA damage by BQ and BQSBn-2 were compared. The DNA damage by BQ was decreased by increasing the EA concentrations. On the other hand, BQSBn-2 had a DNA damaging activity following the EA pretreatment. In order to examine whether 3-BHA is metabolized in forestomach, 3-BHA and BQ levels in the mucosa of forestomach were measured by HPLC with an electrochemical detector. The concentrations of BQ in mucosa correlated with the 3-BHA dose levels from 0.01% to 0.1% 3-BHA. The concentration of BQ in mucosa was approximately 1/4000 of the concentration of 3-BHA in mucosa at the dose level of 1% 3-BHA. The present results indicate that BQ and its thiol conjugates are the active metabolites from 3-BHA in forestomach and may play an important role in inducing carcinogenicity of 3-BHA in F344 rats.
Recent studies have demonstrated an increasing number of cases of allergy in economically developed societies. Many of these allergic reactions are mediated by IgE antibodies whose levels are under genetic control. However, this large increase of allergy prevalence cannot be explained by genetic mutations; comprehensive lifestyles may also play roles in determining total IgE levels. Total IgE levels were determined from serum samples taken from 706 hard metal workers who responded to a questionnaire including 17 items related to physical and mental health practices. Five factors tending to normalize IgE upward and three tending to normalize IgE downward when we keep good lifestyles were extracted using MANOVA analysis. We therefore constructed a Health Practice Index in Allergic reactions (HPIA); eight physical and mental health practices were significantly (P less than 0.05) associated with cumulative elevations or suppressions of total IgE levels when sex, age and environmental factors were controlled for. Multivariate analyses demonstrated a dramatic synergism (Relative Risk greater than 2.0, P less than 0.05) of unhealthy lifestyles determining a bipolar high risk for elevated or suppressed IgE levels which in turn may result in allergic diseases or immuno-suppression. Maintenance of healthy lifestyles may prove beneficial for reducing the prevalence of allergic disorders.
We demonstrated that only membrane-associated protein kinase C (PKC) activity increased in the bilateral hippocampus (HIPP) up to 4 weeks and in the amygdala/pyriform cortex (AM/PC) at 4 weeks after the last kindled seizure. The enhancement of the membrane-associated PKC activity exceeds the increase in the protein concentration, which was observed in part. The overwhelming increase in the PKC activity should be of significance in the long-term maintenance of the kindling phenomenon.