Biomedical subjects

F Sasaki

Publications and source records attributed to F Sasaki.

At least 73 records · Page 4Linked to original sources

PubMed1998

Immunocytochemical differences in adenohypophyseal cells among adult Mongolian pony mares, stallions, and geldings.

OBJECTIVE: To analyze the sex difference in 6 kinds of adenohypophyseal cells of Mongolian ponies and the effect of prepubertal orchidectomy on adenohypophyseal cells. SAMPLE POPULATION: Pituitary glands collected from 15 adult Mongolian ponies, 5 to 10 years old: 5 stallions, 5 mares, and 5 geldings, orchidectomized between the ages of 1 and 2 years. PROCEDURE: Morphologic comparison of 6 kinds of adenohypophyseal cells among mares, stallions, and geldings was done, using immunocytochemistry and morphometry. RESULTS: A sex difference was evident in the percentage of somatotrophs, gonadotrophs (follicle-stimulating hormone [FSH] and luteinizing hormone [LH] cells), and lactotrophs in adult ponies: somatotrophs were more numerous (P = 0.0003) in stallions (approx 40%) than in mares (approx 25%), whereas FSH and LH cells and lactotrophs were more numerous (P = 0.0116, P = 0.0044, P = 0.0085, respectively) in mares (approx 10, 20, and 24%, respectively) than in stallions (approx 6, 15, and 15%, respectively). Prepubertal orchidectomy markedly reduced the proportion of somatotrophs (approx 28%; P = 0.0016) and increased that of lactotrophs (approx 22%; P = 0.0318) in geldings, compared with stallions. The LH cell area was larger in mares than stallions (P < 0.0001). Prepubertal orchidectomy increased FSH (P = 0.0005) and LH (P < 0.0001) cell areas in adult geldings, compared with stallions. CONCLUSIONS: A sex difference exists in adenohypophyseal cells of adult ponies: somatotrophs are more abundant in stallions; FSH and LH cells and lactotrophs are more abundant in mares. Our data indicate that equine testes during postnatal life may stimulate development of GH cells while suppressing development of FSH and LH cells and lactotrophs. The effects of prepubertal orchidectomy on pony somatotrophs and lactotrophs differ greatly from effects on those cells in mice.

Animals↗

PubMed1998

[Lung abscess resulting from esophageal carcinoma successfully treated with intraesophageal covered self-expandable metallic stent].

An 82-year-old man was admitted to our hospital with high fever and back pain. He already suffered from esophageal carcinoma and expandable metallic stent had been inserted because of esophageal stenosis. A chest x-ray film obtained on admission showed infiltrative shadows in the right lower lung filled. The diagnosis of lung abscess was made on the basis of aspirate findings. Despite closed drainage, antibiotic treatment, and fasting therapy, progressive pulmonary infiltrates developed. Esophagography and esophagoscopy revealed that an esophageal fistula due to an advanced esophageal carcinoma had caused the lung abscess. An additional covered self-expandable metallic stent (EMS) was placed on the surface of the esophageal carcinoma, close to the esophageal fistula. This promptly resolved the lung abscess. Our conclusion was that the covered-EMS can be effective for the palliation of esophagorespiratory fistulas.

Aged↗

PubMed1997

The effect of Cu2+ on rat pulmonary arterial rings.

In the current study, Cu2+ was tested for its ability to relax vessels and to accumulate cyclic GMP (cGMP) in rat pulmonary artery employing rat extrapulmonary arterial rings. Cu(2+)-induced relaxation was endothelium and concentration (in the range from 10(-7) to 10(-4) M) dependent. The content of cGMP in the rings was increased 1.7-fold with 10(-4) M Cu2+. NG-Monomethyl-L-arginine abolished both the copper-induced relaxation and the increase in cGMP of rings. Cu2+ and zaprinast, which inhibits phosphodiesterase activity, caused a synergistic increase in cGMP level in the rings, suggesting that Cu2+ enhanced cGMP level through a mechanism different from that of zaprinast, probably as a consequence of elevated accumulation of nitric oxide (NO). The magnitude of vasorelaxation observed due to simultaneous addition of Cu2+ and acetylcholine was additive, not synergistic. Cu2+ did not augment relaxation induced by exogenously added NO donor. These results suggest that Cu2+ elevates NO level in the rings not by prolonging the half-life of NO, but by activation of endothelial nitric oxide synthase and subsequently potentiating the action of NO on vascular tone.

Acetylcholine↗

PubMed1997

Effects of maternal bilateral ureteral ligation on formation of the glomerular basement membrane in fetal rat kidney.

BACKGROUND: The present study was designed to clarify development of filtration property of fetal renal glomerulus when maternal kidney is dysfunctional. MATERIALS AND METHODS: Maternal bilateral ureteral ligation was performed on days 17, 19, and 21 of pregnancy. One day after each operation, cationized ferritin (CF), native ferritin (NF), and horseradish peroxidase (HRP) were injected, respectively, in the fetuses. Distribution of the tracers in the fetal kidneys was investigated electron microscopically. RESULTS: On fetal day 20, clustered CF particles were present in the laminae rarae interna and externa of the glomerular basement membrane of the fetuses from ureter-ligated mothers, while the clusters were arrayed in three to four layers in that of the fetuses from sham-ligated ones. On fetal day 22, a relatively large amount of CF particles was present in the lamina rara externa in the fetuses from ureter-ligated mothers when compared to that in the age-matched control fetuses. On fetal days 20 and 22, the number of NF particles was decreased, and shortening of the time for filtration of HRP through the glomerular basement membrane was observed in the fetuses from the ligated mothers. CONCLUSIONS: These results suggest that dysfunction of maternal kidneys causes accelerated formation of fetal glomerular basement membrane and stimulates glomerular function in filtration in fetal rat kidney.

Animals↗

PubMed1997

Imaging diagnosis of alveolar echinococcosis in young patients.

We review the imaging findings in seven children with alveolar echinococcosis of the liver. Calcification was seen on plain abdominal films in five of seven patients (66.6 %); the calcifications were small or coarse with irregular margins. Ultrasound was performed in four cases, identifying the lesions in all four as small calcifications with or without cysts. Computed tomography (CT) was performed in four cases and showed small calcifications, calcifications surrounding a cyst, or an aggregate of calcifications. Angiography was performed in all seven patients and showed changes of intrahepatic arterial stretching, overgrowth of small arteries, and a honeycomb pattern in the capillary phase. Venography revealed compression of the inferior vena cava in two patients. Serum screening together with ultrasonography and CT are useful for diagnostic imaging of alveolar echinococcosis.

Adolescent↗

PubMed1997

Growth hormone-releasing hormone (GHRH)-GH-somatic growth and luteinizing hormone (LH)RH-LH-ovarian axes in adult female transgenic mice expressing human GH gene.

We have examined alterations in the hypothalamo-pituitary GH-somatic growth axis and the hypothalamo-pituitary LH-ovarian axis in a line of transgenic ICR mice expressing human GH (hGH) under the influence of the whey acid protein promoter. Transgenic female mice weighed twice as much as control females and were infertile. The size of the anterior pituitary (AP) was 1/3 that of the controls. In transgenic mice, acinar cells in the mammary and mandibular glands displayed hGH-immunoreactivity, and plasma hGH was detected by radioimmunoassay. In the medial basal hypothalamus (MBH) of transgenic females, the immunoreactive-GHRH level was decreased (P<0.01). There was a corresponding reduction in the number of GHRH-immunoreactive neurons in the arcuate nucleus (ARC) and in the immunostaining of GHRH nerve terminals in the median eminence. The level of somatostatin (SRIH) in the MBH was increased (P<0.05), and SRIH-immunoreactive neurons in the periventricular nucleus (PeV) were increased in size and number in transgenic mice. The MBH level of LHRH in transgenic animals was greater (P<0.01) than in controls, although there was no apparent difference in the number of LHRH-immunoreactive neurons or in LHRH level in the preoptic area. There are fewer SRIH- and LHRH-immunoreactive neurons in the ARC in transgenic mice. Cells in the AP for GH, PRL, and LH were fewer in transgenic mice. The ovary suffered disturbance of follicular development and of corpora lutea formation. These results demonstrate that chronic overproduction of hGH may profoundly affect the organization of the GHRH/SRIH-GH-somatic growth axis and the LHRH-LH-ovarian axis due to reduction of GHRH-, SRIH- and LHRH-neurons in the ARC and increase of SRIH-neurons in the PeV.

Animals↗

PubMed1997

Different female reproductive phenotypes determined by human growth hormone (hGH) levels in hGH-transgenic rats.

The effect of continuous human GH (hGH) secretion on female reproduction was studied in adult female transgenic rats expressing the hGH gene with a mouse whey acidic protein (mWAP) promoter. Two lines of transgenic female rats carrying the mWAP/hGH gene were established and used in the study. One was characterized by relatively high levels of serum hGH (high line), and the other had relatively low levels (low line). High-line female rats had recurring, pseudopregnancy-like estrous cycles accompanied by increased serum progesterone levels for 2 wk after ovulation, and they were fertile. In these rats, luteinization occurred spontaneously without cervical stimulation, probably due to high levels of serum hGH, which has prolactin (PRL)-like activity in the rat. Although low-line female rats had recurring, regular 4-day estrous cycles, they were sterile. In these rats, pseudopregnancy could not be induced by mating or by mechanical cervical stimulation. PRL surges following cervical stimulation were not detected, and PRL secretion was not induced by a dopamine antagonist, metoclopramide. The ovarian tissue in this line had a much higher number of corpora lutea and grew much heavier than in normal littermates, suggesting impairment of PRL-induced structural luteolysis. Suppression of PRL secretion in low-line rats was, at least in part, due to a marked decrease in the number of lactotrophs in the pituitary. The present study shows that the serum hGH level plays a crucial role in regulating luteal function in female transgenic rats expressing the hGH gene.

Animals↗

PubMed1997

Hyaluronidase activity in human pus from which Streptococcus intermedius was isolated.

Hyaluronidase (HAase) activity was detected in both a human pus sample and the culture supernatant of the only bacterial isolate from the pus, Streptococcus intermedius, using a zymographic technique. The optimum pH range for HAase activity was similar for both samples. Although the bands showing the strongest HAase activity of these samples differed from each other with respect to molecular size, both samples were equally inhibited by an antiserum raised against HAase of S. intermedius. These results suggest that S. intermedius may produce HAase in vivo as well as in vitro, and that this enzyme and/or its fragments may play an important role in host tissue degradation.

Adult↗

PubMed1997

Two transcription factors, E1AF and N-myc, correlate with the invasiveness of neuroblastoma cell lines.

The ets transcription factor E1AF can activate several matrix-degrading metalloproteinase (MMP) genes and is implicated in enhancement of tumor cell invasion. Here we compared the invasive activity of five human neuroblastoma cell lines (TGW, GOTO, SK-N-BE, SK-N-SH and SK-N-AS), which exhibit distinct levels of N-myc amplification, together with the expression of E1AF. Extracellular matrix-degrading proteases and their inhibitor proteins, which play an important role in local invasion, were also analyzed. The activity to invade through reconstituted basement membrane was high in cells (TGW, GOTO, and SK-N-BE) with N-myc amplification, and these cells produced relatively large amounts of E1AF mRNA, correlating with the invasive activities. Of several matrix metalloproteinases (MMPs) and a tissue inhibitor of MMPs (TIMP), only membrane-bound type 1 MMP (MT1-MMP) was specifically detected in N-myc-amplified cells, suggesting a role of MT1-MMP in neuroblastoma cell invasion. MMP-2 (72 kD type IV collagenase), TIMP-1 and TIMP-2 were expressed in all five cell lines. Urokinase-type plasminogen activator was undetectable. These findings indicate that the transcription factors E1AF and N-myc are related to malignant phenotypes of neuroblastoma.

Adenovirus E1A Proteins↗

PubMed1997

A study of granulated metrial gland cells in the pregnant, alymphoplasia (aly/aly) mice.

During pregnancy, a population of uterine NK cells, commonly called granulated metrial gland (GMG) cells, differentiates in the uterus of both immune competent and various immunodeficient mice. Regulatory mechanisms controlling the differentiation of GMG cells are not fully known. It has been proven that GMG cells are derived from bone marrow, appear under the influences of progesterone and estrogen, do not require the presence of an embryo, and are associated in rodents with decidualization of the uterine stroma. Mice of genotype aly/aly are genetically deficient in lymph nodes and Peyer's patches due to a lymphoid-associated mesenchymal disorder. They are considered to be a useful model for the study of interactions between lymphocytes and stromal components. This immunodeficient animal is completely different from nu/nu and scid/scid mice who differentiate GMG cells during pregnancy. To determine whether the differentiation of GMG cells depends on mesenchymal interactions in the uterus, aly/aly mice were studied histologically between days 10 and 14 of pregnancy for differentiation of GMG cells and development of the metrial gland. Metrial gland tissue was present and appeared normal in aly/aly mice. There were no significant differences in the distribution of GMG cells in comparison to control pregnant aly/+ mice. Fewer GMG cells were present in aly/aly mice than aly/+ mice on days 12 and 14 of pregnancy. The features of individual GMG cells were different on days 10 and 12 of pregnancy. GMG cells in aly/aly mice were small in size and the granules were poorly developed. By day 14, however, GMG cells acquired a mature size and the granules appeared mature. It is likely that GMG cell differentiation was delayed in pregnant aly/aly mice, due to a mesenchymal disorder affecting metrial gland development in this animal.

Animals↗

PubMed1997

A case of a pony with Cushing's disease.

The pars intermedia of the pituitary gland, and plasma ACTH and cortisol levels in the pony, which was first diagnosed in Japan as indicating equine Cushing's disease, were examined by immunohistochemistry and radioimmunoassay, respectively. The pars intermedia was greatly enlarged and most of its cells were immunoreactive for antisera to both adenocorticotropic hormone (ACTH) and beta-endorphin (beta-End). The plasma ACTH level was elevated when clinical symptoms appeared. The present results reveal that equine Cushing's disease in this pony was induced by the hypersecretion of ACTH and beta-End from the enlarged pars intermedia of the pituitary gland.

Adrenal Glands↗

PubMed1997

[Detection of GBV-C RNA among non B non C hepatocellular carcinoma patients].

Recently, an RNA virus member of the flaviviridae, GBVirus C(GBV-C) was isolated from the serum of patient with cryptogenic hepatitis, but clinical significance for this virus has been not known now. To estimate the prevalence of GBV-C, we investigated the presence of GBV-C RNA by reverse transcription-nested polymerase chain reaction in the serum from various liver disease patients. The results were summarized as follows: [Table: see text] Among these, only 5 patients gave positive results, and these 5 cases had the history of blood transfusion before. Especially both non B non C HCC patient and non A non B non C fulminant hepatitis patient were negative for GBV-C on admission, while positive after blood transfusion as treatment. In the non B non C HCC patient, GBV-C RNA persisted over a period of several months after transfusion, while no remarkable elevation of ALT was observed. These results demonstrated that GBV-C/HGV may be transfusion-transmissible, and may not associated with severe chronic liver disease such as liver cirrhosis or HCC.

Biomarkers↗

PubMed1997

Immunocytochemical localization of adrenocorticotropic hormone-immunoreactive cells of the pars intermedia in thoroughbreds.

OBJECTIVE: To analyze and characterize adenoma and hyperplasia of the pars intermedia (PI) of Thoroughbred mares. ANIMALS: 165 Thoroughbred mares, without clinical signs of hyperadrenocorticism that had been euthanatized or had died, of causes such as sudden death, colic, pneumonia, or trauma, and were necropsied. Five of those horses, 17 to 25 years old, had a large pituitary gland at necropsy. Eight mares, 5 to 15 years old with normal-size pituitary gland, were selected at random for comparison. PROCEDURE: A morphologic comparison of the pituitary gland between horses with and without tumors of the PI was conducted by use of immunocytochemistry and morphometry. RESULTS: In horses with normal pituitary gland, the PI was supplied by a vast capillary or sinusoidal plexus, which connected that in the pars distalis (PD) with that in the pars nervosa (PN). Cells of the PI stained slightly with ACTH antiserum, but some cells in the border region, which is contiguous to the PD, were strongly ACTH immunoreactive. At necrospy, horses with an enlarged pituitary gland also had adenoma of the pituitary gland involving the PI. Cells of the border region were hypertrophied and stained strongly with ACTH antiserum. The area and number of individual tumor cells of the border region of the PI of horses with adenoma were significantly increased, compared with those in horses with normal pituitary gland. CONCLUSIONS: Cells of the PI-PD border region may secrete substantial quantities of ACTH, owing to stimulation by corticotropin-releasing factor. Adenoma and hyperplasia of the PI in Thoroughbred mares may be associated with hyperadrenocorticism.

Adenoma↗

PubMed1996

Local Recurrence after Conservative Surgery for Breast Cancer.

The advent of limited operative therapy for breast cancer has produced both good cosmetic results and local recurrence. In our department we treated 38 cases with conservation surgery for early stage breast cancers between February 1988 and October 1994, and local recurrence occurred in 2. PATIENT 1. A 56-year-old-woman had a 1 x 0.8 cm tumor in the C region of the left breast. A quadrantectomy with axillary dissection (level 2) was performed as the margin of the nipple side was negative, followed by entire breast irradiation (50 Gy). Approximately four years after the first operation she developed a local recurrence in the CD region of the breast. A salvage mastectomy with subclavicular lymph node dissection was performed. After the second operation she appears to be healthy. PATINENT 2. A 54-year-old-woman noticed a 1 cm tumor located in the EAC region of the left breast. Excisional biopsy showed solid-tubular carcinoma. The distance between the nipple and the tumor was only 0.7 cm. A wide excision with axillary dissection (level 2) was performed as the margin of the nipple side was negative on the frozen section. Neither irradiation of the entire breast nor the adjuvant chemotherapy could be performed. After a three and a half year follow up local recurrence beneath the operative scar was recognized, and an additional wide excision was performed. A half year has passed since the second operation, there have been no signs of recurrence and she appears to be healthy. In conclusion, we experienced two local recurrences in 38 cases of breast conservation surgery for early breast cancers. One patient had multicentric cancers with histologically different types: mucinous and noninvasive ductal carcinoma, and another had a very short distance between the nipple and the tumor and did not undergo chemotherapy or radiotherapy.

Journal Article↗

PubMed1996

Analysis of the core region of HCV genome isolated from patients with chronic hepatitis C during intervals of normal ALT concentration.

We determined the core region nucleotide and amino acid sequences in specimens from two patients with chronic hepatitis C during intervals of normal and elevated alanine aminotransferase (ALT) concentrations. When the ALT concentrations remained normal, the serum HCR-RNA concentration exceeded that before therapy and most of the clones that could be sequenced had a deletion or an amber mutation. The clones isolated from a HLA B44-positive patient had a mutation at amino acid 91. These results suggest that expression of the wild-type HCV core region genome may be associated with liver cell damage.

Aged↗

PubMed1996

Effect of probucol, an oral hypocholesterolaemic agent, on acute tobacco smoke inhalation in rats.

1. We hypothesized that probucol, an oral hypocholesterolaemic agent, can suppress the oxidant stress induced by acute tobacco smoke inhalation in rats. We determined lung tissue glutathione (reduced and oxidized), lipid peroxide, tocopherol and plasma elastase inhibitory capacity, ferroxidase activity and lipid peroxide in rats after inhalation of tobacco smoke. 2. Rats treated with the probucol diet for 3 days or 4 weeks equally showed no suppression of plasma elastase inhibitory capacity and ferroxidase activity compared with control rats after acute tobacco smoke inhalation, although both animals treated with probucol for 3 days or 4 weeks had pharmacologically effective concentrations of probucol to lower plasma cholesterol but plasma cholesterol in rats treated with probucol for 3 days was still in the normal range. 3. Probucol treatment for 4 weeks lessened tobacco smoke-induced suppression of lung tissue glutathione, attenuated tobacco smoke-induced increases in lung tissue lipid peroxide and did not alter lung tissue tocopherol compared with control (lungs). 4. These findings demonstrate that probucol, via its antioxidant ability, confers a protective effect on lung exposed to acute tobacco smoke inhalation.

Animals↗

PubMed1996

Airway wall dimensions during carbachol-induced bronchoconstriction in rabbits.

Airway wall area is an important determinant of airway narrowing. We hypothesized that in cross-sectioned peripheral airways, the wall area internal to the outer smooth muscle border (inner wall area) would decrease and the airway wall area external to the outer smooth muscle layer (adventitial area) would increase during bronchoconstriction because of the relocation of blood and/or fluid between these compartments. To test this hypothesis, we used anesthetized open-chest rabbits and measured airway wall dimensions and smooth muscle shortening of membranous airways after carbachol-induced bronchoconstriction using morphometric techniques. Acute (3-min) and sustained (40-min) bronchoconstriction was induced by aerosol nebulization of carbachol and compared with saline treatment. After physiological measurements, the heart base was snared, and the lung and heart were excised en bloc and frozen by using liquid nitrogen while a transpulmonary pressure of 2 cmH2O was maintained. The lung was processed for light-microscopic examination by using a freeze substitution technique. Results show that adventitial area was significantly decreased after sustained but not acute bronchonconstriction. The mechanism of this change, which contradicts our hypothesis, is unclear. However, the decrease of adventitial area could increase rather than decrease the effect of lung parenchymal tethering and attenuate airway narrowing.

Administration, Inhalation↗

PubMed1996

Phagocytotic processing of apoptotic bodies of transitional ameloblasts by MHC Class II-expressing macrophages in rat incisor.

We examined the processing of apoptotic ameloblast fragments at the transitional stage by immunocytochemistry and electron microscopy. Both macrophages and epithelial cells in the enamel organ ingested apoptotic bodies. MHC Class II antigen expression and the phagolysosomal nature of the macrophages were further examined by immunoelectron microscopy using OX6 and ED1 antibodies followed by HRP- or gold-conjugated secondary antibodies. The results showed that macrophages in the enamel organ at the transitional stage expressed MHC Class II antigens at their plasma membranes and that the same cells contained apoptotic fragments in ED1-positive vacuoles. We suggest that diverse immunological responses, such as the self-antigen presentation, may be invoked in the process of apoptosis.

Acid Phosphatase↗