Biomedical subjects
Publications and source records attributed to M Akatsuka.
We examined the effects of the bacterial filter and the type of epidural catheter on the flow rate of a disposable balloon infuser. The presence or absence of bacterial filters, and the material of the catheter did not influence the flow rate. On the other hand, the flow rate becomes smaller, as the diameter of the epidural catheter is reduced.
The Infectious Agents Surveillance Center, the National Institute of Health, Japan, received 17,265 reports from 1982 to 1993 on cases from whom adenovirus was isolated or detected; 85% from 57 public health institutes and the other 15% from two national hospitals and two commercial diagnostic laboratories. The followings were found. Three major diseases caused by adenovirus were upper respiratory tract infection, gastroenteritis, and conjunctivitis. Patients of upper respiratory tract infection numbered 6,837 (40% of all patients due to adenovirus), the identified serotypes being in order of frequency types 3, 2, 1, and 5. Those of gastroenteritis numbered 1,636 (9.5%). From 40% of the gastroenteritis patients, adenovirus was detected by electron microscopy or immunochemical methods without cultivation. From the remaining 60%, virus was isolated in tissue culture; the serotypes of the isolates resembled those causing upper respiratory tract infection. Patients of conjunctivitis numbered 3,437 (20%), the frequency being in order of types 3, 4, 8, 37, and 19. Conjunctivitis due to types 3 and 4 prevailed every summer; type 3 was isolated often from children with pharyngo-conjunctival fever and the other four types were mostly from adults with epidemic keratoconjunctivitis. Type 3 had a unique feature not seen in other types: it was most frequently isolated, causing upper respiratory tract infection, gastroenteritis, conjunctivitis, and pharyngo-conjunctival fever. Reports on isolation of type 7, which has been reported to cause severe pneumonia in many other countries, were as few as 28 (0.2%).
Two rages of epidemic of aseptic meningitis (AM) due to echovirus 30 (E30) in Japan were analyzed with respect to two sources of information, AM incidence and E30 isolation, both gathered through the National Epidemiological Surveillance of Infectious Diseases. The first E30 epidemic spread throughout Japan in 1983 and ceased within the year. The second epidemic, starting in 1989, continued for the three successive years, and in the last year, 1991, the total E30 reports numbered 4,061, the largest number of a single virus type ever reported. Although the epidemic showed temporal and geographical shift and lasted for one or two years in some areas, most laboratories reported the largest number of E30 isolation in 1991. Among E30-yielding cases with clinical information during 1982-1992, the associating frequency with AM was as high as 82.5%. Other central nervous system involvements such as encephalitis, myelitis, encephalomyelitis and/or paralysis were reported in 36 E30-yielding cases and their monthly and age distributions were different from those of AM cases. The proportion of such disease among E30-yielding cases (0.60%) was close to that of other enteroviruses (0.56%). During the epidemics, E30 was isolated more frequently from cerebrospinal fluid than was E4 or E9 which prevailed coincidentally. E30 was most frequently isolated from cases of 4-7 years of age, sharing the common characteristic pattern of age distribution with other enteroviral meningitis. E30-yielding cases, however, involved a large number of older age groups than those of other enterovirus infections, and this tendency was the most pronounced in the first epidemic year, 1983. The contribution of these E30 epidemics on the yearly trend of clinically reported AM incidence and on the shift of its age distribution was also analyzed.
Effects of hyaluronan (HA) on the prostaglandin E2 (PGE2) production induced by recombinant human interleukin-1 beta (rhIL-1 beta) in rabbit articular chondrocytes were studied in vitro. The rhIL-1 beta-induced PGE2 production was dose-dependently inhibited by HA. HA with the highest molecular weight (M(r) = 2.0 x 10(6)) exhibited an inhibitory effect that was statistically more significant than the same polymer of lower molecular weights (M(r) = 1.0 x 10(6), 0.5 x 10(6)). This effect was observed in both young and adult rabbit articular chondrocytes. Since PGE2 has been implicated as a mediator of inflammatory joint diseases, our observations suggest that HA may elicit an anti-inflammatory effect by inhibiting PGE2 production.
Effects of hyaluronic acid on the release of elastase from rat peritoneal leucocytes were studied by measuring the leucocyte elastase activity using a synthetic peptide substrate. Leucocyte elastase release was induced by opsonized zymosan, 12-O-tetradecanoyl phorbol-13-acetate (TPA) and N-formyl-L-methionyl-L-leucyl-L-phenylalanine combined with cytochalasin B. Calcium ionophore A23187 potentiated the action of TPA on leucocyte elastase release, whereas hyaluronic acid inhibited leucocyte elastase release regardless of the method of stimulation. Inhibitory effects of hyaluronic acid were dependent on its concentration and molecular weight. Hyaluronic acid of the highest molecular weight (2.0 x 10(6)) indicated a potent inhibitory effect on elastase release. Our present findings suggest that hyaluronic acid may elicit an anti-inflammatory effect by inhibiting leucocyte elastase-dependent pathological processes.
The effects of hyaluronan on neutrophil-mediated cartilage degradation were studied in an in vitro model. Rat peritoneal neutrophils were incubated for up to 18 h with the neutralized cartilage of bovine nasal septa using N-formyl-L-methionyl-L-leucyl-L-phenylalanine combined with cytochalasin B, or opsonized zymosan, as a stimulation agent of neutrophils. Hyaluronan inhibited the neutrophil-mediated cartilage degradation by reducing the release of sulfated glycosaminoglycans from the cartilage. Inhibitory effects were dependent on concentration and molecular weight of hyaluronan. These results suggest that hyaluronan with a high molecular weight plays an important role in protecting the articular cartilage in inflamed joints from neutrophil injury.
We injected botulinum toxin to treat hemifacial spasm, and investigated the effects and the patient's impression of this treatment. Average duration of improvement lasted about 3.5 months in both the initial treatment group and the recurrent group. However the patients in the recurrent group received fewer units of botulinum toxin than those in the initial treatment group. Except for local paralysis that disappeared within a month, there were very few complications. Most patient were satisfied with this treatment. We conclude that the treatment of hemifacial spasm with botulinum toxin is both simple and useful.
Minimal residual disease (MRD) in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph1 ALL) who received allogeneic (n = 9) or autologous (n = 6) bone marrow transplantation (BMT) was evaluated by the polymerase chain reaction (PCR) for the bcr-abl transcript. Twelve patients received BMT at the time of hematologic and cytogenetic remission. However, MRD was detected in 8 of 10 patients evaluated. Seven patients, including three who had MRD before BMT, continue to have a disease-free survival 5 to 64 months after BMT. Twenty-one specimens obtained from these patients at various times after BMT did not show MRD. In three patients, MRD detected just before BMT seems to be eradicated by BMT protocol. The other eight patients developed cytogenetic or hematologic relapses 2 to 8 months after BMT. Seven of 14 samples from these patients demonstrated MRD, which preceded clinical relapse by 3 to 9 weeks. Thus, this technique for the detection of MRD appears to be useful for the more precise assessment of various antileukemia therapies and for early detection of leukemia recurrence.
An in vitro study on the effects of hyaluronan (HA) on interleukin-1 alpha-induced prostaglandin E2 (PGE2) production in human osteoarthritic synovial cells indicated that PGE2 induction was suppressed by HA in a dose- and molecular weight-dependent manner.
In Japan, aseptic meningitis cases due to enterovirus infections increase every summer in various degrees with an incidence peak usually in July. During the past 11 years from 1981 through 1991, a total of 8,595 enterovirus isolations from aseptic meningitis cases were reported from 54 participating laboratories. Eight enterovirus types caused large epidemics; more than 100 isolations of each type from aseptic meningitis cases were reported for every epidemic year of the respective type. They were coxsackievirus (C) types B3 and B5, echovirus (E) types 4, 6, 7, 9, 18 and 30. Among these, the highest meningitis-associating frequency was reported for E30, representing 82.6% of the total isolations reported for the type during this period, followed by E4, 71.1%. The frequencies of E9, E7, E6 and CB5 were in a range from 54.5% to 44.4%, while that of E18 was 37.7% and that of CB3 21.0%. During the epidemics, enterovirus-associated meningitis was most frequently reported among children of 4-7 years of age. High frequencies were also shown in infants less than 1-year of age in some types. A total of 4,240 enteroviruses were isolated from cerebrospinal fluid of aseptic meningitis cases, representing 49.3% of the cases with enterovirus isolation.
This report presents an overall distribution of poliovirus isolations in Japan, where poliomyelitis has been under control over two decades as a result of legal administration of two doses of the trivalent live oral poliovirus vaccine of the Sabin strains (OPV) to children under 48 months of age. During the past 12 years from 1980 through 1991, a total of 1,126 poliovirus isolations from humans and 268 isolations from sewage/river water were reported by respectively 49 and nine of the participating laboratories. Type 2 was most frequently isolated from children after administration of one dose of OPV, followed by type 1 and type 3. On the contrary, after the second dose of OPV, the rate of isolation of type 3 exceeded those of type 2 and type 1. Seasonal and age distribution of poliovirus isolations from both humans and sewage/river water paralleled the OPV vaccination schedule in Japan. One percent of the isolations were, however, from infants younger than the vaccination-scheduled ages and 5% were from children older than those ages, including one each from 15 and 16 years olds. The data indicate that the poliovirus has silently been disseminated from vaccinated children to others and the community, thus suggesting repeated transmission of the viruses. The fact that some elder children had poliovirus colonization in their alimentary tracts indicates a potential risk of infection of such a population when exposed to a wild virus and of becoming a source of transmission to others.
Twenty-seven patients with aplastic anemia (20 severe: 7 moderate) were treated with combined immunosuppression consisting of antilymphocyte globulin (ALG: Ahlbulin, Green Cross Co., Osaka, Japan) and high-dose methylprednisolone. Danazol or meptiostane was administered concurrently for at least 3 months. Ten of 27 patients had sustained improvement in hematopoiesis within 3 months of treatment. Three patients with hematological response had a recurrence of pancytopenia 12-36 months after the combined immunosuppressive therapy. Six patients died due to fungal pneumonia (2), hepatic failure (2), interstitial pneumonitis (1) and complication following allogeneic bone marrow transplantation (1). By life table analysis, the survival rate for all patients was 76 +/- 8% at 4 years, with 70 +/- 10% survival rate for patients with severe aplastic anemia and 100% for patients with moderate aplastic anemia. The factors predicting the good response to the therapy were a longer interval from diagnosis to the therapy and higher counts of platelet and reticulocyte at admission.
In Japan, herpangina cases increase every summer with an incidence peak in July. During the past eight years from January, 1982 to December, 1989, a total of 3,974 viruses from herpangina cases were reported from 47 participating laboratories, and coxsackie A (CA) viruses accounted for most of them, 3,055 (76.9%). The major types associated with herpangina were, in order of frequency, CA4, 10, 5, 6, 2 and 3, representing 87.2%-80.8% of total isolations reported for each respective type in this period. Eighty-four point four percent of the total virus isolations were from children at four years of age or younger. More than 80% of total CA virus isolations were from nasopharyngeal specimens and nearly 90% of the viruses were isolated in mice.
Laboratory reports of isolation of echovirus serotype 18 (E18) slightly increased in the summer of 1987 followed by a sharp increase with a peak in July, 1988. A total of 1,094 isolations were reported during these two years from 39 laboratories participating in the National Epidemiological Surveillance of Infectious Agents in Japan. When compared with the previous E18 outbreaks, a higher proportion of children at two years of age or under (58.3%) and a much higher incidence of exanthem (46.4%) were remarkable. Meningitis-associated isolations were reported in 30.6%, less than half of the percentage of the previous epidemic.
The optimal dose and adverse effects of midazolam for premedication were evaluated in 45 patients undergoing local anesthesia. The patients were divided into 3 groups and administered midazolam intramuscularly: group-A 0.075 mg.kg-1, group-B 0.1mg.kg-1, group-C 0.125 mg.kg-1. In this study, concerning sedative and hypnotic effects, the administration of midazolam (0.075-0.1mg.kg-1) showed satisfactory results except in conduction anesthesia of upper extremities (brachial plexus block). However, severe decrease in PaO2 was observed in relatively younger patients. Therefore, it is necessary to observe patients carefully during perioperative period.
A case of acoustic neurinoma with multiple intratumoral hemorrhages is reported. A 56-year-old male noted sudden hearing reduction in his left ear in October of 1985. The diagnosis of a local physician was sudden deafness. About 10 months later, he had two episodes of severe headache without nausea or vomiting. The patient was hospitalized in October of 1986. Neurological examination cerebellar ataxia. cerebellar ataxia. Plain and enhanced computed tomography revealed only an unremarkable low-density area at the left cerebellopontine angle. In contrast, magnetic resonance imaging (MRI) clearly demonstrated a large (3 x 4 x 5 cm), multicystic tumor in the site. On exposure of the tumor at surgery, most of the cysts were found to be filled with a dark red or xanthochromic fluid. The tumor was completely removed following numerous cyst punctures to decrease its volume. There was no evidence of subarachnoid hemorrhage. Histological examination showed a typical acoustic neurinoma. The cyst wall contained numerous telangiectasia-like lesions. The initial symptom of this patient was sudden hearing loss, which is an atypical manifestation of acoustic neurinoma. The massive intratumoral hemorrhage was thought to be caused by telangiectatic lesions in the cyst wall. MRI clearly demonstrated the hemorrhagic cysts within the tumor, especially in the posterior fossa.
Effect of bromocriptine on induction of ovulation and occurrence of pregnancy was examined in patients with normoprolactinemic ovulatory disturbances. The patients under study (53 in number) were divided into two groups, A and B, depending on the effect clomiphene had on the ovulatory responses and the occurrence of pregnancy. Of the group A, patients (21 in number), who had failed to show any ovulatory response to clomiphene, 8 patients ovulated on bromocriptine alone. Three out of 13 patients who complained of sterility became pregnant. Three out of 8 patients who had not ovulated on bromocriptine therapy alone ovulated on a combination of bromocriptine and clomiphene, and 2 out of these 3 cases became pregnant. Of the group B patients (31 in number), who had failed to become pregnant in spite of ovulatory responses to previous clomiphene therapies, 7 out of 23 became pregnant, who complained of sterility when on bromocriptine alone. Out of 12 cases who had failed to get pregnant on the bromocriptine alone, 2 patients became pregnant on the combination of bromocriptine and clomiphene. These data may indicate that the bromocriptine or the combined therapy of bromocriptine and clomiphene is useful for the treatment of patients with ovulatory disturbances or sterility who do not respond to the clomiphene therapy.
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