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Biomedical subjects

T Tamura

Publications and source records attributed to T Tamura.

At least 1,333 records · Page 74Linked to original sources
PubMed1981

Structure of the baboon endogenous virus genome: nucleotide sequences of the long terminal repeat.

The entire nucleotide sequence of the long terminal repeat (LTR) of baboon endogenous virus (BaEV) M7 was determined, which consisted of 554 base pairs (bp). At both ends of the LTR, 13 bp sequences, AAATGAAAAGTAA and TGATTCTAACATC, were detected to be inverted repeats. The structure with these inverted repeats resembles those of other retroviruses and transposable elements. a Hogness box, TATAAAA, and a putative poly(A)-addition signal, AGTAAA, were present within the right-hand half of the LTR, where the initiation and termination of the viral RNA synthesis seems to occur in the integrated BaEV genome. The primer-binding site of at least 14 bp long was found just outside of the LTR where the strong stop DNA started, and the primer for reverse transcription in BaEV seemed to be tRNAPro. Several structural features are commonly detected in the LTRs of BaEV and other retroviruses. Our studies suggest that BaEV has evolved from a common ancestor with other mammalian type C viruses. Close relationships between BaEV and a feline endogenous virus, RD114, are demonstrated.

Cloning, Molecular↗
PubMed1981

Structure of the baboon endogenous virus genome: cloning of circular virus DNA in bacteriophage lambda.

Linear, small and large circular forms of unintegrated viral DNAs were detected in Hirt supernatant fraction of human cultured cells infected with baboon endogenous virus M7. The circular M7 DNAs were cloned in bacteriophage lambda, Charon 28. Seventeen independent clones were isolated and analyzed by restriction endonuclease mapping. Nine clones were carrying a viral sequence of 8.6 kilobase pairs (kb) with two tandem repeats of 0.6 kb, which correspond to the large circular form of the unintegrated M7 DNA. Eight other clones had the viral insert of 8.0 kb, i. e., the small circular form, and were deleted one of the repeated sequences. The repeated sequences correspond to the long terminal repeats of 0.6 kb, located at both ends of the linear M7 DNA of 8.6 kb. One of the recombinants of the large circular M7 DNA had an inversion of 2.5 kb. One end of the inverted sequence was near the terminus of the long terminal repeats and the other in the gag gene region. The inversion seems to be occurred by integration of a viral DNA within itself during early periods of infection. The mechanism of the processes leading to integration is discussed from the structure of these unintegrated M7 DNAs as the precursors.

Bacteriophage lambda↗
PubMed1981

IgE associated nephropathy in a patient with subcutaneous eosinophilic lymphoid granuloma (Kimura's disease).

A patient with subcutaneous eosinophilic lymphoid granuloma (Kimura's disease) associated with a high serum IgE level and a marked blood eosinophilia, had a glomerulonephritis with electron dense deposits in mesangial, paramesangial, subendothelial, intramembranous and epimembranous areas. By immunofluorescence, all the glomeruli showed predominant depositions of IgE and IgG along the paramesangial areas and capillary walls together with complement components. The germinal centers in the lymph follicles formed in both the subcutaneous granuloma and the kidney interstitium also contained mainly IgE and IgG but no complement components. These features of this disease suggest that the glomerular lesion is one of the systemic manifestations of Kimura's disease.

Adult↗
PubMed1981

13q-/r(13) mosaicism.

A 2-month-old female infant with typical features of the 13q- syndrome was found to be a hitherto unreported mosaic consisting of 46,XX,del (13)(q22)/46,XX,r(13)(p13q22). She has not been able to maintain normal values of serum Na and Cl since the second day of life: this may be induced by cerebral dysgenesis.

Brain↗
PubMed1981

Availability of vitamin B6 and pantothenate in an average American diet in man.

The availability of vitamin B6 and pantothenate in an average American diet was assessed healthy male volunteers. The subjects received two types of diets, both nutritionally equivalent to the average American diet: period 1 (35 days), semipurified formula diet (low in both vitamins) with daily supplements of 1.1 mg pyridoxine and 8.2 mg pantothenate; period 2 (35 days), natural food sources, providing 2.3 mg vitamin B6 and 11.5 mg pantothenate/day; period 3 (21 days), formula diet, providing 2.7 mg pyridoxine and 8.2 mg pantothenate/day. Daily protein intake was 96 g throughout the study. Vitamins in food and urine samples were determined microbiologically and plasma pyridoxal phosphate by a tyrosine apodecarboxylase radioassay method. Compared to the availability of the pure vitamins as 100%, the availability of vitamin B6 ranged from 61 to 81% with a mean of 71% using plasma pyridoxal phosphate data, and ranged from 73 to 92% with a mean of 79% according to urinary vitamin B6 data. Availability of pantothenate ranged from 40 to 61% with a mean of 50%, according to urinary pantothenate data. The average American diet used in our study contained 1.7 and 5.8 mg/day of available vitamin B6 and pantothenate, respectively.

Adult↗
PubMed1981

Effect of immune heterozygous spleen cell transfer on resistance to mouse hepatitis virus infection in nude mice.

The role of cell mediated immune response to mouse hepatitis virus (MHV) infection in mice was studied by transferring spleen cells from immune heterozygous littermates (nu/+). A suppressive effect on viral growth was seen in infected nude (nu/nu) mice, whereas immune nu/+ serum transfer had no effect. The protective effect of immune nu/+ spleen cells was significantly reduced by treatment with anti-theta serum plus complement but not with anti-Ig serum. In infected nu/nu mice which received transfers of immune nu/+ cells, neutralizing antibody appeared although the titer was not high enough to protect nu/nu mice from fatal infection. Histopathologically, lymphocyte infiltration in hepatic lesions was evident in infected nu/nu mice with nu/+ cell transfer, while it was slight without nu/+ cell transfer.

Animals↗
PubMed1981

Echocardiographic study of the Duchenne type of progressive muscular dystrophy.

The present study was undertaken in an attempt to clarify whether or not any relationship exists between the echocardiographic indices of cardiac function and the severity of progressive muscular dystrophy of the Duchenne type (PMD). A total of 75 patients with PMD was used for analysis. Among the echocardiographic parameters measured in the study, the maximal diastolic endocardial velocity (DEVM) and ejection fraction (EF) revealed a gradual decreasing tendency with increasing severity of the disorder. It can be concluded therefore that DEVM and EF may represent useful indices in the assessment of cardiac function in PMD.

Adolescent↗
PubMed1981

Transient changes in ventilation and cardiac output at the start and end of exercise.

In order to clarify the nature of the regulatory mechanism of the hyperventilation observed at the transition from rest to exercise, cardiac output and ventilation changes in response to submaximal bicycle exercise given as a step function were studied in five healthy men. Cardiac output was determined non-inversively by using a type of impedance plethysmography. It was found that (1) both the cardiac output and ventilation started to increase during the first 10 sec after the start of exercise; (2) the rate of increase in the initial response was abrupt in ventilation but rather gradual in cardiac output: (3) the fast response was followed by a slow response with an exponential time course, the half response time of which ranged between 10 and 45 sec in cardiac output and between 5 and 80 sec in ventilation. The half time increased in proportion to an increase in the work rate and (4) end-tidal pressure of carbon dioxide monitored simultaneously showed a slight decrease at 10 to 15 sec after the start of exercise. It was therefore concluded from the above observation that the initial phase of the exercise-induced hyperpnea is probably of a neurogenic origin.

Adult↗