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Biomedical subjects

Y Katoh

Publications and source records attributed to Y Katoh.

At least 253 records · Page 14Linked to original sources
PubMed1986

[A case of posttraumatic vascular abnormality similar to dural arteriovenous malformation].

A case of posttraumatic vascular abnormality similar to dural arteriovenous malformation is reported. A 21-year-old man was injured in the traffic accident and admitted to our hospital with comatose state. Bilateral carotid angiograms revealed no abnormal findings. Then, he was treated conservatively as a diagnosis of cerebral contusion. Nine years after the initial admission, he was fallen into comatose state suddenly and admitted to a local hospital. On the next day, he was transferred to our hospital. Neurological examination disclosed comatose state, right oculomotor palsy, and left hemiparesis. CT scan showed a crescent shaped high density area in the right subdural space, right temporal intracerebral high density area, and left frontal low density area, suggesting right acute subdural hematoma, right temporal intracerebral hematoma, and left frontal old cerebral contusion respectively. Right carotid angiogram revealed an abnormal vascularity in the right middle fossa, which was fed by the middle meningeal artery and drained into the superior sagittal sinus and the transverse sinus. Surgical treatment was performed immediately. Following the evacuation of intracerebral hematoma, the abnormal vascular mass suggesting a nidus of arteriovenous malformation was removed totally, that was attached to the dura mater. Pathological specimen showed large veins and arteries with thrombus, however, no characteristic feature of arteriovenous malformation. Then, this was thought to be an arteriovenous fistula between the branches of middle meningeal artery and the veins of fibroglial scar following by the cerebral contusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Characterization of growth factor(s) produced by chemically transformed hamster dermal fibroblasts.

Cell lysates from transformed hamster dermal fibroblasts (HDF cells) induced colony formation of normal HDF cells in soft agar medium and also stimulated proliferation of normal HDF cells in medium supplemented with plasma-derived serum (PDS). The colony forming activities of cell lysates correlated well with their growth stimulating activities in PDS-supplemented medium. The growth factor(s) were shown to be sensitive to trypsin and dithiothreitol (DTT), but heat stable. However, these transformed HDF cell lines did not all produce tumor nodules when injected into hamsters. This was not due to immunological rejection because similar results were obtained in hamsters treated with anti-hamster thymocyte serum (ATS). Thus it was concluded that production of these growth factor(s) by transformed HDF cell lines is not itself sufficient for acquisition of complete malignancy in vivo.

Animals↗
PubMed1985

In vivo effects of epidermal and fibroblast growth factors on DNA replication in mouse skin.

A method was developed for measuring in vivo DNA synthesis after exposure to epidermal growth factor (EGF) or fibroblast growth factor (FGF) in a local area of mouse skin using ring-shaped forceps in combination with autoradiography. The technique should be useful for analysing the effects of growth factors on individual cells of the skin in vivo. EGF induced semisynchronized DNA synthesis in basal cells of the epidermis dose-dependently, but FGF did not. Time course study showed that EGF-induced DNA synthesis in basal cells increased with time for 24 h, and then decreased rapidly. EGF-induced DNA synthesis in basal cells was proportional to the time exposed to EGF (0-60 min). FGF and EGF both had little effect on dermal fibroblastic cells. The discrepancy between in vivo observations and those with cultured mammalian cells is discussed.

Animals↗
PubMed1985

[Studies on the endocrinological metabolism of the parathyroid. I. The production of renal calcinosis by cyclic AMP injection in rat].

We found that a few patients with urolithiasis had normal parathyroid hormone levels but high cyclic AMP excretion. The purpose of this paper was to study the endocrinological mechanism. Male rats were given intraperitoneally dibutyryl cyclic AMP (DBcAMP), a derivative of cyclic AMP, per 100 gm of body weight for 50 days. Feed and water were supplied ad libitum. Crystal formation or calcification in mainly the dystal tubules and collecting system were found in 3 out of 10 rats, and renal calcium stones in 2 rats. The cyclic AMP of the renal parenchyma, especially the renal medulla, was elevated by more than 100 times after DBcAMP administration. Serum calcium levels, urinary calcium and phosphate excretion, and the adrenaline levels of the renal parenchyma were significantly increased. Serum parathyroid hormone was slightly enhanced, but vitamin D and the noradrenaline levels of the renal parenchyma were not changed. Based on these findings, it is suspected that stone formation in rats injected DBcAMP occurs through the action of DBcAMP on the renal tubules to increase urinary calcium excretion and to make renal stones as a form of primary hyperparathyroidism.

Animals↗
PubMed1985

[Studies on the endocrinological metabolism of the parathyroid. II. Influence of ACTH on parathyroid function and calcium metabolism].

Parathyroid hormone (PTH) is strongly concerned with the pathogenesis of urinary stones. PTH is mainly regulated by the serum calcium concentration and not by other hormones, as is usually the case. We studied whether PTH is also regulated by adrenocorticotrophic hormone (ACTH) or not. ACTH (0.25 mg) was injected intravenously to 17 patients with primary hyperparathyroidism PHP, 7 patients with urolithiasis, 7 patients with malignant hypercalcemia, and 6 control subjects. Serum calcium was significantly increased in only PHP. The serum calcium increase rate showed a significant positive correlation with serum alkaline phosphatase, and a negative correlation with the preinjected serum calcium. PTH was slightly increased in all four groups. Serum cortisol and ACTH concentrations were not significantly different among the groups. PTH concentration in a culture medium of parathyroid tissues increased after ACTH addition. Serum calcium was significantly increased after ACTH injection in an adrenalectomized rat, and decreased in a parathyroidectomized rat. From our data and those of others, it appears that ACTH acts on the adrenal glands to decrease the serum calcium concentration, and might act directly on the parathyroid gland or bones to increase it.

Adrenocorticotropic Hormone↗
PubMed1985

Ankle instability: comparison of primary repair and delayed reconstruction after long-term follow-up study.

Twenty-five consecutive primary ligament repairs and 40 delayed reconstructions for lateral collateral ankle ligament injuries were studied. Response to a questionnaire provided a 94% subjective evaluation at a mean of 9.5 years after surgery; 97% of patients were satisfied with the surgical result. Clinical examination, stress radiography, and biomechanical gait analysis studies were performed on 39 patients at four years or more after surgery (mean, 9.6 years). In 14% of those with ligament repair and 41% of those with reconstructive procedures, mean residual talar tilt with stress testing was 3.2 degrees and 5.2 degrees, respectively. Gait studies did not demonstrate a consistent abnormal gait pattern, even with side slope walking, and did not correlate with the talar tilt values. There was no significant measurable difference between the results of repair and reconstruction. Thus, most severe Grade III sprains can be managed nonoperatively, and if late residual instability occurs, a reconstructive procedure can be offered with confidence that the result will be equivalent subjectively and roughly comparable objectively to that of the immediate repair.

Adolescent↗
PubMed1985

[Fundamental and clinical studies on aspoxicillin in the field of pediatrics].

Fundamental and clinical studies were performed with aspoxicillin (ASPC), a new developed injectable broad penicillin, in pediatric infectious diseases, and the following results were obtained. Pharmacokinetics ASPC was administered to 2 cases at a dose of 20 mg/kg by one shot intravenous injection. The mean half-life (T 1/2) was 1.17 hours. The mean urinary excretion rate was 58.4% during 6 hours after ASPC treatment. In 3 cases of intravenous drip infusion with a period of 1 hour at a dose of 10 mg/kg (2 cases) and 20 mg/kg (1 case), the half-lives (T 1/2) were 1.7 hours, 3.5 hours and 1.0 hour, respectively. The urinary recovery rate during 6 hours after administration was 57.7%, 32.6% and 42.7%, respectively. At only one case treated with 10 mg/kg intravenous drip infusion, the half-life was prolonged and urinary excretion rate was lower than other 2 cases. Clinical study ASPC was administered 50-80 mg/kg/day for 4-8 days to 22 children comprising 6 tonsillitis, 2 bronchitis, 6 pneumonia and 8 urinary tract infections. Clinical efficacy was excellent in 13 cases, good in 8 cases and fair in 1 case, the total cure rate was 95%. As for the clinical response classified by diagnosis, the each efficacy rate of tonsillitis, bronchitis and pneumonia was 100%, and that of urinary tract infection was 87.5%. Clinical side effect and abnormal laboratory findings were not observed in any cases. From the above results, it was concluded that ASPC was one of the useful secure drug for treatment of infections in pediatric field.

Adolescent↗
PubMed1984

Characterization of the major mRNAs from adenovirus 2 early region 4 by cDNA cloning and sequencing.

The sequences at the splice junctions of many early region 4 (E4) mRNAs from adenovirus 2 (Ad2) were determined by analysis of cDNA clones. The cDNAs were synthesized from poly(A)+ mRNA isolated from HeLa cells early during Ad2 infection. A standard library was constructed, in pBR322, from double stranded cDNAs initiated by oligo-dT priming. Approximately 1% of total recombinants contained E4 sequences, however among eighty clones analyzed in detail, only four contained the 5' leader sequence. A second library was prepared using a new method that led to a greatly increased representation of desired clones. This method employed oligo-dT to prime the synthesis of the first strand and an oligonucleotide ligated to pBR322, whose sequence was present in the 5' leader, to prime the synthesis of the second strand. With this method the percentage of recombinants containing E4 sequences ranged between 15 and 50% of the total colonies. Virtually all of these E4 cDNA clones contained the 5' leader sequence and several hundred were analyzed by comparing the results from single channel dideoxy sequencing reactions. Nine unique sequence patterns were identified and representative clones were completely sequenced.

Adenoviruses, Human↗
PubMed1984

Characterization of the growth responses of hamster fibroblasts and chondrogenic cells to fibroblast growth factor.

The effects of fibroblast growth factor (FGF) on hamster dermal fibroblasts and chondrogenic cells, both of mesodermal origin, were compared with special reference to growth stimulation and morphological changes in monolayer cultures, and colony formation in semisolid medium. FGF (10 to 200 ng/ml) caused appreciable cell proliferation of dermal fibroblasts but not of chondrogenic cells, while FGF (50-200 ng/ml) caused very marked dose-dependent morphological changes in monolayer cultures and colony formation in semisolid medium of both fibroblasts and chondrogenic cells. It is suggested that FGF is the same type of growth factor as the transforming growth factor(s) because, like the latter, it induces drastic morphological changes of normal mesodermal cells in monolayer cultures and their colony formation in semisolid medium.

Animals↗
PubMed1984

[Light-microscopic studies of locus coeruleus region of the mouse].

In an attempt to give some contribution to the morphology of locus coeruleus (LC) in the ddY mouse (weighing about 20 g), we made light-microscopic investigations using several staining methods in normal condition. First, we studied the cytoarchitectonics and cell numbers of LC by the Klüver-Barrera method and amine demonstrating wet fluorescent method. LC of the mouse measured 600 +/- 60 micrometers in antero-posterior extent in the dorso-lateral tegmental area. At the rostral part of LC small number of constituent cells were disseminated, the middle part (principal part) showing the triangle-shaped cell accumulation with an apex directing to the IV ventricle. The caudal part forming small accumulation of cells ended directly beneath the IV ventricle. Number of unilateral LC cells amounted to 1250 +/- 92 by Klüver-Barrera method, while 1326 +/- 44 by the wet fluorescent method. The LC was cytoarchitectonically divided into the dorsal and ventral parts. The cell size of the dorsal part averaged (16.2 +/- 2.8) x (25.5 +/- 4.6) micrometers along the longest and shortest axes, while that of ventral part (17.3 +/- 3.1) x (30.2 +/- 5.6) micrometers.

Animals↗