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Biomedical subjects

S Shimoda

Publications and source records attributed to S Shimoda.

At least 109 records · Page 6Linked to original sources
PubMed1987

Stimulation of prostaglandin E2 production by phorbol esters and epidermal growth factor in porcine thyroid cells.

Effects of phorbol esters and epidermal growth factor (EGF) on prostaglandin E2 production by cultured porcine thyroid cells were examined. Both phorbol 12-myristate 13-acetate (PMA) and EGF stimulated prostaglandin E2 production by the cells in dose related fashion. PMA stimulated prostaglandin E2 production over fifty-fold with the dose of 10(-7) M compared with control. EGF (10(-7) M) also stimulated it about ten-fold. The ED50 values of PMA and EGF were respectively around 1 X 10(-9) M and 5 X 10(-10) M. Thyroid stimulating hormone (TSH), however, did not stimulate prostaglandin E2 production from 1 to 24-h incubation. The release of radioactivity from [3H]-arachidonic acid prelabeled cells was also stimulated by PMA and EGF, but not by TSH. These results indicate that both PMA and EGF are potent stimulators of prostaglandin E2 production, associated with the activity to stimulate arachidonic acid release in porcine thyroid cells.

Animals↗
PubMed1987

Presence of epidermal growth factor receptors on human thyroid membranes.

The nature of epidermal growth factor (EGF) receptors in normal and pathological thyroid membranes was studied on a crude membrane fraction (10,000 X g pellet) of tissue homogenate. Optimal binding of 125I-EGF to human thyroid membranes was obtained at 25 degrees C with 1-h incubation at pH 7.4. The study revealed the presence of both high and low affinity receptors in normal and pathological thyroid membranes. The association constants of high affinity receptor (3.2 X 10(-9) mol/l) and of low affinity receptor (1.8 X 10(-8) mol/l) observed in normal thyroid membranes were similar to those of thyroid membranes from neoplastic as well as thyrotoxic thyroid tissues. [3H]thymidine incorporation into DNA of cultured human thyroid cells was stimulated by EGF in a dose-dependent manner. A half-maximal stimulation was found around 1 X 10(-10) mol/l. These results suggest that EGF may have a possible role in the regulation of thyroid growth and function in physiological and pathological situations.

Animals↗
PubMed1986

Pattern of fibronectin distribution in human lung cancer.

The pattern of fibronectin (FN) distribution in human lung cancer was studied by indirect immunofluorescent staining, and by the peroxidase-antiperoxidase method in a total of 60 surgical specimens. They comprised 8 small cell carcinomas, 4 large cell carcinomas, 19 squamous cell carcinomas, 28 adenocarcinomas, and 1 adenoid cystic carcinoma. Of the 60 specimens 13 were FN-positive. They included 4 large cell carcinomas, 4 small cell carcinomas, 3 poorly differentiated squamous cell carcinomas, and 2 poorly differentiated and 1 moderately differentiated adenocarcinomas. On the other hand, none of the well differentiated carcinomas was FN-positive around tumor cells. Our data suggest that undifferentiated, or poorly differentiated carcinomas of the lung tend to be FN-positive.

Adenocarcinoma↗
PubMed1985

Forskolin stimulation of adenylate cyclase in human thyroid membranes.

Forskolin stimulates adenylate cyclase in human thyroid membranes approximately 7-fold with half-maximal stimulation occurring at 5-10 microM. Guanine nucleotides are not required for stimulation of the enzyme by forskolin. Forskolin-stimulation is additive or greater than additive with that of TSH or Gpp(NH)p- (above 1 microM). Different from TSH- or Gpp(NH)p-stimulation of adenylate cyclase, uncoupling of the guanine nucleotide-binding regulatory component by increasing concentrations of MnCl2 did not result in uncoupling of forskolin stimulation. The finding indicates that forskolin may mainly act on the catalytic component of adenylate cyclase. From the present study, it is suggested that the diterpene forskolin stimulates adenylate cyclase in human thyroid membranes by a novel mechanism that differs from TSH- or Gpp(NH)p-stimulation, and that the diterpene may be a useful tool to investigate the metabolism of thyroid and its regulation in normal and pathological situations.

Adenylyl Cyclases↗
PubMed1984

[Thyroid functions in nonthyroidal illness: specific changes in serum levels of thyroid hormones related in illness and the correlation between thyrotropin and free thyroid hormones in patients with nonthyroidal illnesses].

In order to assess the thyroid function of patients with nonthyroidal illness, 292 patients with nonthyroidal illness were employed in the present study. These patients were then subdivided into 6 groups according to their original illness. The groups consisted of patients with malignant illnesses (19 males and 10 females; mean age of 59.7 yr.), with chronic hepatitis (14 males and 8 females; mean age of 55.2 yr.), with liver cirrhosis (5 males and 6 females, mean age of 60.4 yr.), with uremia who had been receiving constant hemodialysis 2 approximately 3 times per week (52 males and 38 females; mean age of 48.1 yr.), with diabetes mellitus (50 males and 43 females; mean age of 52.3 yr.) and with cerebrovascular accident (21 males and 26 females; mean age of 74.9 yr.). In addition, 34 healthy persons (15 males and 19 females; mean age of 41.6 yr.) were also employed as controls. Because the differences between mean ages in these groups were significant, the relationship between age and thyroid function was examined. Significant positive correlations between age and total thyroxine (TT4) (r = 0.19; p less than 0.01), and reverse triiodothyronine (rT3) (r = 0.175; p less than 0.01) were found. A negative correlation was also found between age and total triiodothyronine (TT3) (r = 0.231; p less than 0.01). The serum levels of rT3 were elevated in patients with neoplasma and liver cirrhosis but significantly low in patients with uremia. These characteristic findings were correlated with the severity of each original disease such as % motarity, serum levels of cholinesterase, blood urea nitrogens and the blood sugar control in the diabetics. In these circumstances, multiple correlation analyses were performed in order to assess whether there might exist a negative feedback mechanism between thyrotropin and FT4/FT3. The highest partial correlation coefficient was obtained between thyrotropin and FT4. It might, therefore, be concluded that in patients with a nonthyroidal illness, decreased levels of serum thyroid hormones indicate not only the severity of the illness but also the supposed presence of a hypothyroid state.

Adult↗
PubMed1984

Growth hormone response to thyrotropin releasing hormone in a pellagrin.

An abnormal hyperresponse of GH to intravenous injection of TRH in a 66-year-old female pellagra patient with typical 3'D's was reported. Diagnosis of pellagra was mainly based on her clinical course and manifestations, although serum levels of nicotinic acid and serotonin were within the normal range. Serum vitamin A and B2 levels were low. However, these findings did not exclude the diagnosis. The abnormal GH response to TRH observed in this patient was decreased at 2 months and thoroughly disappeared at 10 months after admission. GH response to arginine showed an exaggerated and sustained response on admission, decreased at 2 months and showed an almost normal pattern at 10 months after admission. TSH and prolactin response to TRH were normal throughout the clinical course. LH and FSH response to LH-RH were exaggerated, suggesting post-menopausal hypogonadism. Cortisol response to ACTH showed slightly sustained reactions at both times of the provocation. Oral glucose tolerance test revealed a slight impairment in this patient. These results suggest that pellagra is one of the disorders which exhibit an abnormal hyperresponse of GH to intravenous administration of TRH.

Aged↗
PubMed1984

Lowering effect of diphenylhydantoin on serum free thyroxine and thyroxine binding globulin (TBG).

To evaluate the effect of anticonvulsants on serum levels of free thyroxine (FT4) and thyroxine-binding globulin (TBG), 32 patients with epilepsy receiving long-term anticonvulsant treatment (mean duration 81.8 +/- 8.9 months) were employed in the present study. The serum levels of total thyroxine (TT4), total triiodothyronine (TT3), T3 resin uptake (T3U) and thyrotrophin (TSH) were also measured. Free thyroxine index (FT4I) was calculated from TT4 and T3U. Mean levels of these thyroid function tests were as follows: 5.52 +/- 1.51 micrograms/dl (TT4), 1.16 +/- 0.32 ng/dl (FT4), 101.5 +/- 16.2 ng/dl (TT3), 27.5 +/- 2.6% (T3U), 19.64 +/- 3.97 micrograms/ml (TBG), 1.50 +/- 0.36 (FT4I) and 2.21 +/- 0.18 microU/ml (TSH). These values except for T3U and TSH were significantly lower than normal values (P less than 0.01). Using correlation analysis, a significant dose-dependency (daily doses) was found between diphenylhydantoin (DPH) and TT4, FT4 and TBG. Other anticonvulsants (barbiturates, carbamazepine, primidone) or duration of treatment were not significantly correlated with thyroid function tests. Therefore serum levels of DPH were also measured in 19 out of 32 patients receiving anticonvulsant treatment. Significant negative correlation was found between serum levels of DPH and FT4 (r = -0.65) and DPH and TBG (r = -0.61).

Adult↗
PubMed1984

[Multiple duodenal carcinomas associated with multiple gastric cancers].

Because of the rarity of primary duodenal cancer, the coexistence of this disease with gastric cancer is very rare. The case presented herein suffered from two carcinomas of the duodenum and six gastric cancers. The patient was 71-year-old man who underwent subtotal gastrectomy and pancreatoduodenectomy. Pathologic studies showed that all of the gastric and one of the duodenal cancers were limited to the mucosal layer and that the other duodenal tumor invaded to the pancreas. Several cases of double cancers in the duodenum and the stomach have been reported in Japan, and this is first of multiple carcinomas of the duodenum associated with multiple gastric cancers.

Adenocarcinoma↗