Regulatory mechanism in PHB [poly-(hydroxybutyrate)] accumulation by cyanobacteria, especially by a thermophilic isolate, Synechococcus MA19 was reviewed in comparison with a genetically engineered strain. The strain, MA19 accumulates PHB under nitrogen starved and photoautotrophic conditions (MA19-N). Little PHB synthase activity was detected in crude extracts from the cells grown in nitrogen sufficient conditions (MA19 + N). The activity was detected exclusively in membrane fractions from MA19 + N. The change of the enzyme activity was insensitive to chloramphenicol, which suggests post-translational activation. In vitro, acetyl phosphate activated PHB synthase in membrane fractions from MA19 + N, and the extent of activation depended on the concentration of acetyl phosphate. Phosphotransacetylase which catalyzes the conversion of acetyl-CoA to acetyl phosphate was detected in crude extracts from MA19-N but not in those from MA19 + N. These results suggested that intracellular acetyl phosphate concentration could be controlled, depending on C-N balance and intracellular acetyl-CoA concentration. On the contrary, in genetically-engineered cyanobacterium (transformant with PHB synthesizing genes from Ralstonia eutropha), it did not seem to be PHB synthase but acetyl-CoA flux that limits PHB synthesis. The closer association of PHB granules with thylakoid membranes in MA19 is suggested than that in the genetically-engineered cyanobacterium, which may reflect the difference of distribution of PHB synthase. Transposon-mutagenesis was used to acquire mutants of its altered PHB regulatory mechanism. PHA production by cyanobacteria was considered from the aspects of photobioreactors.

Acyltransferases↗

PubMedDate not supplied

HTLV-I-associated myelopathy (HAM) in Tokushima Prefecture--geographical and clinical studies in an area between endemic and non-endemic areas of HTLV-I infection.

The geographic distribution and clinical features of patients with HTLV-I-associated myelopathy (HAM) in Tokushima prefecture were investigated. Nine patients were found prior to December 1990. The minimal prevalence was estimated as 1.1 per 100,000 in the general population, and 1 per 1,309 in HTLV-I-seropositive persons. Seven patients were found in the southern district facing the Pacific Ocean, but only 1 patient each was found in the northern and western districts. The age at disease onset ranged from 15 to 53 yr (average 33 yr). The ratio of male to female patients was 1:8. Adult T cell leukemia was associated with HAM in 1 patient, and Hashimoto's disease in 2 patients. These cases have not been reported previously. The route of transmission of HTLV-I was concluded to be vertical in 4 patients and horizontal in 4 patients, but was uncertain in 1 patient. No evidence of transmission by blood transfusion was found in these patients.

Adult↗

PubMedDate not supplied

Immunohistological localization of autoantigens detected by serum autoantibodies from mice with experimental autoimmune orchitis without using adjuvants.

Recently, a murine model of testicular autoimmunity was produced in mice by subcutaneous injections with viable syngeneic testicular germ cells alone, without depending on the use of any adjuvants or immunopotentiators. In this article, histological localization of autoantigens detected by circulating autoantibodies was immunohistochemically studied by reacting the immune sera with frozen sections of testes from mice of various ages. The study showed that the reactivity of immune sera was detected in the testis sections of normal mice older than 24 days of age but not in those of mice younger than 20 days of age. The immunostain was detected at proacrosomal, acrosomal, and other cytoplasmic regions of variously shaped developing spermatids but never on pachytene spermatocytes, basal compartment germ cells, or the supporting tissue of the seminiferous tubules.

Adjuvants, Immunologic↗

PubMedDate not supplied

Overview of clinical studies of childhood acute lymphoblastic leukemia for more than ten years by the Japanese Children's Cancer and Leukemia Study Group.

Since 1981, the Children's Cancer and Leukemia Study Group (CCLSG) has developed a series of protocols for treatment of acute lymphoblastic leukemia (ALL) in childhood. In the first randomized controlled study of the 811 protocol (1981-1983) a comparison of conventional daily 6-mercaptopurine and methotrexate with a pulsed regimen of the two drugs was performed. The superiority of the pulsed regimen was shown. In the next 841 protocol (1984-1987) a comparison of two drugs and three drugs during induction therapy was conducted. The three-drug regimen resulted in a significantly higher event-free survival (EFS) rate. In the 874 protocol (1987-1990) two regimens with or without cranial irradiation were randomly compared, and there was no significant difference between the two regimens for the standard-risk group. To further improve the EFS rate a risk group-directed protocol 911 was conducted starting in January 1991. Life-table analysis of serial CCLSG protocols revealed that the outcome of overall ALL has gradually improved with an increase of the EFS rate; 41.4% +/- 3.6% at 14 years for the 811 protocol, 51.3% +/- 3.5% at 11 years for the 841 protocol, 56.7% +/- 3.1% at 8 years for the 874 protocol, and 78.2% +/- 3.1% at 4 years for the more recent 911 protocol.

Antineoplastic Combined Chemotherapy Protocols↗

PubMedDate not supplied

A novel monoclonal antibody, H9, directed against the core protein of MUC1 mucin.

MUC1 mucin is a target protein for many monoclonal antibodies. Human MUC1 detected by a murine anti-KL-6 monoclonal antibody that recognizes a sialylated carbohydrate chain has been designated KL-6/MUC1. Given the heterogeneous antigenicity of KL-6/MUC1, we established a new murine monoclonal antibody, H9, that reacts with epitope DTRP (Asp-Thr-Arg-Pro) peptides within the immunodominant region of the tandem repeat of MUC1 mucin. The reactivity of the H9 antibody differs from that of other previously reported antibodies that recognize the tandem repeat region of MUC1. Immunohistochemical experiments indicate that the reactivity of the H9 antibody is similar to that of other antibodies directed against MUC1 core proteins. A new cancer-associated protein detected by a sandwich assay using the H9 antibody as a catcher and the KL-6 antibody as a tracer is designated HK9. Serum HK9 levels showed a high expression level in lung cancer: 51% (19/37 cases) for adenocarcinoma, 39% (11/28 cases) for squamous cell carcinoma, and 67% (10/15 cases) for small cell carcinoma. The HK9 expression in lung cancer increased with cancer progression. These findings suggest monoclonal antibody H9 to be a novel antibody that reacts with an epitope within the tandem repeat region of MUC1, and that the cancer-associated antigen HK9 may have useful tumor-associated properties.

Animals↗

PubMedDate not supplied

Determination of vertebral bone mineral density with new dual energy X-ray absorptiometry using multiple detectors: fundamental studies.

Fundamental studies on the ability of a newly developed 90-detector dual energy X-ray absorptiometry (DEXA) system with a fan beam, the DCS-3000, to determine bone mineral density (BMD) were performed. This new system not only measured BMD precisely, resulting in a fast scan mode in CV of 0.89% and 1.63% for in vitro and in vivo studies, respectively, but also performed data acquisition in a greatly reduced examination time (24 sec). Furthermore, when a rod phantom was used, the linear regression equation obtained between BMD quantified with the QDR-1000 (x) and that quantified with the DCS-3000 (y) was y = 1.250x-0.242. In both healthy subjects and osteoporotic patients, significant positive correlations were obtained between radial BMD and vertebral BMD measured with the QDR-1000 and with the DCS-3000. The correlation for radial BMD was r = 0.533 (p less than 0.001, N = 76), and that for vertebral BMD was r = 0.985 (p less than 0.001, N = 56). Therefore, in addition to safety of operation, the performance of the DCS-3000 was considered to be equal to that of commercially available DEXA systems, indicating that it should be useful in the detection of vertebral bone loss.

Absorptiometry, Photon↗