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Biomedical subjects

S Kikuchi

Publications and source records attributed to S Kikuchi.

At least 415 records · Page 23Linked to original sources
PubMed1987

Variable copy number DNA sequences in rice.

We have cloned two types of variable copy number DNA sequences from the rice embryo genome. One of these sequences, which was cloned in pRB301, was amplified about 50-fold during callus formation and diminished in copy number to the embryonic level during regeneration. The other clone, named pRB401, showed the reciprocal pattern. The copy numbers of both sequences were changed even in the early developmental stage and eliminated from nuclear DNA along with growth of the plant. Sequencing analysis of the pRB301 insert revealed some open reading frames and direct repeat structures, but corresponding sequences were not identified in the EMBL and LASL DNA databases. Sequencing of the nuclear genomic fragment cloned in pRB401 revealed the presence of the 3'rps12-rps7 region of rice chloroplast DNA. Our observations suggest that during callus formation (dedifferentiation), regeneration and the growth process the copy numbers of some DNA sequences are variable and that nuclear integrated chloroplast DNA acts as a variable copy number sequence in the rice genome. Based on data showing a common sequence in mitochondria and chloroplast DNA of maize (Stern and Lonsdale 1982) and that the rps12 gene of tobacco chloroplast DNA is a divided gene (Torazawa et al. 1986), it is suggested that the sequence on the inverted repeat structure of chloroplast DNA may have the character of a movable genetic element.

Base Sequence↗
PubMed1987

Cervical flexion myelopathy: a "tight dural canal mechanism". Case report.

The authors describe a case of flexion myelopathy due to specific morphological changes of the cervical cord, termed a "tight dural canal mechanism." The patient was an 18-year-old man with progressive weakness and muscle atrophy of the left arm. Neuroradiological examination revealed that the lower cervical cord was compressed during flexion of the cervical spine, but that there was no disc disease or cervical vertebral instability. The cord compression was attributed to a pinching mechanism by the posterior border of the vertebral body and the posterior component of the dura on flexion.

Adolescent↗
PubMed1987

[The problems of postoperative adjuvant chemotherapy in gastric cancer].

We studied the survival rate and state of recurrence of histologically curatively resected cases in the 1st (Method II) and the 2nd studies of the Cooperative Study Group of Surgical Adjuvant Chemotherapy for Gastric Cancer. The administration of MMC combined with Futraful was most effective, but there was no difference of survival rate between the patients in the 1st study given Futraful for 3 months and those in the 2nd study given the drug for 12 months. Irrespective of the kind of drug and term of administration, cases with stage I showing recurrence within 2 years after surgery accounted for ca. 50% of all stage I cases recurring within 5 years. In spite of histological malignancy, cases with stage II showing recurrence within 2 years after surgery accounted for ca. 65% of all stage II cases recurring within 5 years. As to the recurrent hazard rate for each recurrent type of case with stage III, all types showed a high peak between 0.5 and 1.5 years after surgery. The peritoneal metastatic hazard rate was the highest. The hazard rates for Groups B (MMC + Futraful) and C (Futraful) were lower than those for Group A (MMC). The above findings suggest the importance of postoperative adjuvant chemotherapy, which is performed repeatedly and intensively for 2 years in order to prevent recurrence.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

[Hydronephrosis in pregnancy and its etiology].

Using ultrasonography, the cause and incidence of hydronephrosis were investigated in humans and rabbits and the following results were obtained. The degree of hydronephrosis was classified into grade I (calyceal diameter; up to 5 mm) to grade V (calyceal diameter; 21 mm or more). In normal non-pregnant women, the calyceal diameter was within grade I. The hydronephrosis was found in 45.5-87.0% of pregnant women in the right kidney and in 29.1-51.0% in the left. Throughout pregnancy, the incidence was significantly higher in the right than in the left. On the 6th puerperal day, the incidence of hydronephrosis was lowered, but the diameter did not return to the non-pregnant level. Comparison of women who practised swimming during pregnancy and those who did not reveal the incidence of hydronephrosis was lower in the swimming group than in the non-swimming. In rabbits, calyceal dilatation increased as gestation advanced and hydronephrosis was found in progesterone-treated ovariectomized rabbits. It was concluded that the hydronephrosis in the 1st trimester was due to increased steroid hormones, but also that, in the 2nd trimester, the combined effect of hormones and mechanical obstruction was responsible for its occurrence.

Adult↗