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Biomedical subjects

S Ihara

Publications and source records attributed to S Ihara.

At least 91 records · Page 5Linked to original sources
PubMed1990

Ontogenetic transition of wound healing pattern in rat skin occurring at the fetal stage.

Full-thickness excisional wounds were made in the dorsal skin of rat fetuses at day 16 and day 18 of gestation. A small patch of skin surrounding the open wound was cut out, mounted on a plastic ring and incubated in an organ culture system. In the presence of serum, the open wound in the day-16 fetal skin closed within three days of culture. During the wound-closure process, no new structures were formed in the wound space, and no conspicuous changes were noted in the histological architecture of the surrounding skin during culture, indicating that the wound closure may result from a centripetal movement of the surrounding skin only. In contrast, the size of the open wound in the day-18 fetal skin remained almost unchanged for one week, but a thin acellular network spread over the wound space within one day of culture. The predominant component of the network was cross-linked fibrin, as disclosed by scanning electron microscopy and sodium dodecylsulfate-polyacrylamide gel electrophoresis followed by immunoblotting. The network served as a scaffold for the ingrowth of fibroblast-like cells. These stage-dependent differences in fetal wound healing were consistent with an in vivo study showing that the day-16 wound was covered with the surrounding skin itself, whereas the day-18 wound was covered with newly formed epidermis and invaded by inflammatory cells. The present investigation strongly indicates the prenatal occurrence of a fetal-to-adult transition in the wound-healing pattern of rat skin.

Animals↗
PubMed1990

[Patient's delay and doctor's delay in the primary treatment cases of pulmonary tuberculosis detected by subjective symptoms].

Delays in case finding were studied for the primary tuberculosis patients who were discharged from our hospital in 1987. Of 321 tuberculosis patients who were released from our hospital in 1987, 171 patients received primary treatment. Eighty one of them had been detected by their symptomatic visits. Patient's and doctor's delays tended to be longer in the cases of males than of females. For both males and females patient's delay tended to be longer in younger age group. Total delay until definite diagnosis by 50% and 80% of all diagnosed were 1.6 months, and 3.5 months respectively. Patients with total delay of more than three months were younger in age and were hospitalized longer than patients with total delay of less than 3 months. All cases with total delay of more than three months were smear positive.

Adolescent↗
PubMed1990

[Pulmonary Tuberculosis in foreigners].

We studied the background and social problems of pulmonary tuberculosis in foreigners which we recently encountered at the National Chiba- Higashi Hospital and the Chiba Anti-tuberculosis Association. 1) The number of foreigners with pulmonary tuberculosis has been increasing year by year, one in 1983, none in 1984 and 1985, one in 1986, two in 1987 and four in 1988. 2) Most of these patients had been already infected or had some symptoms before their arrival to Japan. 3) Their background includes some serious social problems such as troubles in daily life coming from linguistic and cultural differences and economic difficulties, legal problems such as illegality of their stay in Japan, etc. 4) Most of the above cases could not be treated sufficiently because they are foreigners or because of their illegal stay.

Adolescent↗
PubMed1989

Requirement of serum factors for wound closure of embryonic skin in vitro.

Forelimb buds of rat embryos at day 13 of gestation were cut and cultured in Dulbecco's modified Eagle medium. In the absence of serum, the epidermis did not cover the wound surface. In the presence of fetal calf serum or ultroser G, a serum substitute, epidermal wound closure appeared in a concentration-dependent manner within 1 day of culture. Cycloheximide, an inhibitor of protein synthesis, reversibly inhibited wound healing, demonstrating that protein synthesis was required for epidermal wound closure. Dialysis and fractionation of ultroser G indicated that high molecular weight factors (greater than 25,000 d) were required for epidermal wound closure.

Animals↗
PubMed1989

[Extraordinary examinations in tuberculous prevalence areas and family contact examinations].

A survey was made on the actual state of performance of extraordinary examinations done in high tuberculosis prevalence areas and those of family contact examinations of the index cases of tuberculosis during the period between April 1986 and November 1987 in Chiba Prefecture. The results are as follows: (1) Forty-eight extraordinary examinations were performed by 19 public health centers. (2) By these extraordinary examinations, 22 additional tuberculous patients were detected and 143 persons were indicated INH prophylaxis. There were 2 cases of mass tuberculosis infection: from which 19 patients and 140 persons for chemoprophylaxis were detected. (3) Out of 18 extraordinary examinations done for contacts of cases from danger groups, one was done actually for unnecessary case. As to tuberculin tests, they were not performed in 2 groups, and in another case, the test subjects were inappropriate. (4) The examination rate of family members of index cases was as high as 95.4%, whereas the performance of tuberculin tests was not satisfactory, especially as regards to the younger populations. The total performance rate of the tests was 29.0%, and the rate in those below 19 years of age was 56.5%, and the rate in those below 29 was 42.9%. (5) There were 6 families with tuberculosis, which included 14 patients. It is considered that in extraordinary examinations, appropriate setting of subjects and tuberculin tests for younger persons are important; in family contacts examination, tuberculin tests for younger persons are indispensable.

Adolescent↗
PubMed1989

[Group infection of tuberculosis in a private extra-school tutoring institute].

1) Two students of different high-schools were found to have pulmonary tuberculosis by school medical examination. These two students learned in the same private extra-school tutoring institute when they were junior high-school students. Assuming this event as a group infection of tuberculosis in the extra-school tutoring institute, we performed an extraordinary examination on the teachers working there. 2) In the extraordinary examination, a patient who could be judged as the source of infection was found. 3) As a result of extraordinary examination on students learning in the institute, a bimodal distribution was noted in the size of tuberculin test, compared with the results of tuberculin test at the first grade of junior high-school, the reaction was amplified. Twenty four students were subjected to chemoprophylaxis. 4) One case of pleurisy occurred from a student recommended chemoprophylaxis by the ad hoc committee on epidemic of tuberculosis, and the recommendation was neglected by an attending physician.

Adolescent↗
PubMed1988

The 28k and 70k dalton polypeptide components of mouse Ra-reactive factor are responsible for bactericidal activity.

Ra-reactive factor is a complement-dependent bactericidal factor that reacts specifically with Ra chemotype strains of Salmonella, and is ubiquitous in sera of a wide variety of vertebrates. Here we prepared an antiserum by immunizing rabbit with mouse Ra-reactive factor. This serum neutralized markedly the bactericidal activity of the factor. This action of the antiserum was inhibited by the factor whose bactericidal activity has been inactivated by heating for 30 min at 55 degrees C. Component polypeptides with apparent molecular weights of 28k and 70k in the factor were separated by SDS-polyacrylamide gel electrophoresis. They were also found to inhibit the antiserum activity. This indicates that these polypeptides carry the active site of the factor.

Animals↗
PubMed1988

Wound healing in fetal limb organ culture.

The in vitro wound healing responses in whole-limb organ culture of fetal rats at day 19 of gestation were compared with the intrauterine wound repair. In vitro, after a skin incision was made in the lower forelimb, the subcutaneous tissue and the dermis regenerated. Reepithelialization appeared within two to five days. Thus, the wound healing was comparable to the intrauterine fetal wound repair. The whole limb organ culture may be a useful and suitable in vitro test system to study the mechanisms involved in fetal wound healing to search for compounds required in fetal skin regeneration and to test factors tht might influence it.

Animals↗
PubMed1988

Expression of human cytomegalovirus immediate early antigens is responsible for a novel chromatin structure of infected human embryonic lung cells.

Whereas human embryonic lung (HEL) cells displayed chromatin fibers composed of a repeat of conventional nucleosomes of 15 nm in diameter, human cytomegalovirus (HCMV) infection induced transient appearance of a novel chromatin structure composed of a repeat of large ellipsoids of 45-65 nm X 15-30 nm with linkers of 50-60 nm long and 6-7 nm thick. Essentially the same change in chromatin structure could be induced when uninfected HEL cell nuclei were incubated in vitro with a 0.4 M NaCl nuclear extract from HCMV-infected HEL cells expressing immediate early antigens (IEA's) or with a similar nuclear extract from NIH/3T3 cells constitutively expressing HCMV IEA's. The latter cell line was established by transformation of the mouse cells with a plasmid carrying the HCMV major immediate early and immediate early 2 genes. These results together with those of control experiments suggest that the expression of IEA's is directly or indirectly responsible for the appearance of the novel chromatin structure in HCMV-infected HEL cells.

Animals↗
PubMed1987

Recovery of polypeptides from polyacrylamide gels by electrophoretic elution in a centrifugation concentrator.

A method for recovery of polypeptides from polyacrylamide gels by electrophoretic elution in a commercially available concentrator, the Amicon-Centricon sample reservoir, has been devised. The recoveries were greater than 90% with four different polypeptides tested (12.5 to 80 kDa). After elution, sample concentration or salt exchange can be carried out without sample transfer. There were no loss of sample during the postelution procedures when the elution buffer was replaced by 0.01 or 0.05% sodium dodecyl sulfate.

Cytochrome c Group↗
PubMed1987

A new human cytomegalovirus isolate has an invertible subsegment within its L component producing eight genome isomers.

A HindIII cleavage map of the genome DNA of a new isolate of human cytomegalovirus (HCMV), strain Tanaka, was constructed by cosmid cloning and Southern blot hybridization of virion DNA. The genome was found to be unique in that its long (L) component was composed of two subsegments, L1 and L2, and subsegment L2 underwent inversion relative to L1 at high frequency. In addition to the normal inversions of the L and short (S) components, this produced eight genome isomers. The novel invertible subsegment was flanked by an inverted sequence distinct from the inversion-specific a sequence present in the terminal and junction regions of the genome.

Cell Line↗
PubMed1987

High-frequency transfection of mouse FM3A mammary carcinoma cells in suspension culture with plasmid DNA.

High-frequency transfection of mouse FM3A cells, grown in suspension, with plasmid pSV2neo DNA was achieved by incubation of the cells with DNA plus polybrene for 6 h followed by an osmotic shock with a hypertonic NaCl solution. When incubated for 20 min at 34 degrees C, FM3A cells showed resistance to the osmolarity change from 0.1 to 9.0% NaCl in the medium. Within this concentration range, 5-7% gave the highest efficiency of transfection. Both linear and circular forms of plasmid DNA produced transformants with equal efficiency. This method was simple, reproducible, and carrier DNA was not required. The efficiency was about 100 times higher than that of the method with DNA-calcium phosphate precipitates. Transformed cells were stable and different numbers of plasmid DNA copies were detected.

Animals↗
PubMed1986

Cleavage maps of human cytomegalovirus genome (strain Towne) determined by the use of cosmid cloning system.

Virion DNA of human cytomegalovirus strain Towne was partially digested with endonuclease Hind III and fragments larger than 29 kbp were ligated to cosmid pHC79. The whole viral DNA sequence has been cloned in large overlapping segments carried by 32 recombinant cosmid clones (a pIT series). A whole set of Hind III fragments has also been cloned (a pHI series). By using these, we have constructed corrected cleavage maps of strain Towne DNA for Hind III, Bam H I, EcoR I and Xba I.

Chromosome Mapping↗