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Biomedical subjects

T Nishida

Publications and source records attributed to T Nishida.

At least 577 records · Page 32Linked to original sources
PubMed1987

Three-dimensional structure of the Sertoli cell in the shiba goat.

The three-dimensional structure of the Sertoli cell in the miniature "shiba" goat was examined using scanning electron microscopy. In the basal portion of the seminiferous epithelium, spermatogonia and/or spermatocytes were located in compartments enclosed by adjacent Sertoli cells. From the basal aspect, they were situated in successive recesses. In the middle portion, early round spermatids halfway embedded in the Sertoli cell were recognized. The exposed surfaces of these spermatids were wrapped with ramifying processes which were derived from the Sertoli cell. In the apical portion, only the heads of the maturing spermatids invaded the Sertoli cell. As the spermatid matured, the apical Sertoli process varied in range to finally release the spermatid head. It is probably that the maturing spermatids gradually leave the apical Sertoli process and ultimately segregate themselves from the seminiferous epithelium.

Animals↗
PubMed1987

Expression of vasoactive intestinal polypeptide and amylase in a human parotid gland adenocarcinoma cell line in culture.

A neoplastic epithelial cell line initially established in culture from a human parotid gland adenocarcinoma grown in athymic nude mice with a BALB/c genetic background, which has an ultrastructure similar to that of the intercalated duct cell of the salivary glands, was examined for the expression of amylase and vasoactive intestinal polypeptide (VIP). The cultured cells were found by the peroxidase-antiperoxidase (PAP) method to express amylase and ultrastructurally to have secretory granules showing positive immunoreaction with anti-amylase serum. In addition, the cells were found to secrete amylase into the culture medium. The expression of VIP in the cultured cells was observed by the PAP method, immunofluorescent staining method, or immunoelectron microscopy. Moreover, the presence of the polypeptide reactive to antibodies directed against VIP in the cultured cells was confirmed by immunoblotting and radioimmunoassay. These findings indicate that the cells proliferating in culture express both amylase and VIP.

Adenocarcinoma↗
PubMed1987

Characterization of transplant generations of primary rat adenocarcinoma and some chemotherapeutic observations.

Rats (Wistar) bearing subcutaneous implants of tumor fragment of DMBA-induced tumor were used in this study. Studies have been made of their proliferative characteristics, and their response to Cis-dichlorodiammine platinum (CDDP) has been measured. The transplanted tumor appears to be on homogeneous solid structure throughout all transplant generations, although the primary site is concomitant adenocarcinoma showing both glandular and solid structure. Microangiography showed that the transplanted tumor was more hypervascular than the primary tumor. Compared with the previous reports using the primary autochthonous tumor, the antitumor effect of CDDP is excellent and the histologic effect is observed in all areas of the sectioned surface. The transplanted tumor could provide a useful experimental system for the laboratory study of the chemotherapy of ovarian adenocarcinoma and the possibility of predicting ovarian adenocarcinoma seemed to be great because of the morphological similarity.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1987

[Tricuspid regurgitation evaluated by intraoperative epicardial pulsed Doppler echocardiography: investigation of patients with combined valvular diseases].

To evaluate the grade of tricuspid regurgitation (TR) associated with mitral valve disease and to ascertain the operative procedure for the involved tricuspid valve, epicardial pulsed Doppler echocardiography (PDE) was performed during cardiac surgery. Thirty-two patients with mitral valve disease were studied, 17 of whom had only mitral valve lesion; the remaining 15 had combined mitral and aortic valve disease. The patients' ages ranged from 24 to 63 years and averaged 48.3 years. There were nine men and 23 women. Echocardiographic examinations were performed using a Toshiba SSH-60A for parasternal study and a SSH-11A combined with a SDS-10A with a specially-devised flat transducer for intraoperative use. Intraoperatively, the PDE performed was from the right side of the right atrium (RA), referenced by a four-chamber view and a long-axis view of the right ventricular inflow. The sampling volumes were positioned in the inflow of the right ventricle, immediately above the tricuspid valve, the middle and upper areas of the RA, and adjacent to the interatrial septum. PDE was performed before and immediately after the operative procedure and before chest closure. By severity, TR was classified as non -, mild +/-, moderate +, and severe ++, according to the distances attained by the TR signals from the tricuspid valve orifice, and the velocities and durations of the TR signals during systole. The TR signal was recorded in 23 of 32 patients before surgery, whereas it was determined more adequately in 28 patients by intraoperative epicardial PDE. The gradings of TR via the parasternal approach before surgery were as follows: no TR, in nine cases; mild TR, in three; moderate, in 13; and severe, in seven. Intraoperatively, four patients had none; eight had mild TR; 14, moderate TR; six, severe TR before surgical intervention, respectively. In cases with mild or no TR before surgery, TR was rarely detected by contrast echocardiography using saline solution injected into the right ventricle during surgery. The moderate or severe cases before surgery had moderate or severe TR according to the contrast method during surgery, except for one case not operated on for tricuspid valve disease. Tricuspid valve replacement was performed for two patients, and tricuspid annuloplasty or valvuloplasty for eight.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1987

Fibronectin enhances the phagocytic activity of cultured rabbit keratocytes.

To understand corneal stromal wound healing, we investigated the effect of fibronectin (FN) on the phagocytic activity of rabbit corneal keratocytes. The phagocytic activity was measured under a dark-field microscope using polystyrene latex beads coated with either FN, bovine serum albumin, or both. The percentage of phagocytosing cells increased with incubation time. The phagocytic activity was significantly enhanced in a dose-dependent manner by coating beads with FN. Transmission electron microscopic observation demonstrated that latex beads were internalized into the cytoplasm and were surrounded by limiting membranes. These findings indicate that cultured keratocytes have phagocytic activity and that FN shows opsonic effects on the phagocytic activity, suggesting that FN in the injured corneal stroma may play a role in stromal wound repair by opsonic effects.

Animals↗
PubMed1987

Stimulatory effects of fibronectin and EGF on migration of corneal epithelial cells.

The effects of fibronectin and epidermal growth factor (EGF) on the migration of corneal epithelial cells in situ were investigated. When rabbit corneal blocks were cultured in serum-free medium with fibronectin or EGF, corneal epithelial cells migrated on the cut surface of the stroma. Histological and electron microscopic studies revealed that the leading edge of the fibronectin-treated cornea was thin, single-layered epithelium, whereas the leading edge of the EGF-treated cornea was a hypertrophic, multilayered epithelium. By autoradiography with 3H-thymidine, the authors observed that EGF stimulated corneal epithelial cell proliferation; however, fibronectin had no effect on cell proliferation. These results demonstrate that fibronectin and EGF enhance migration of corneal epithelial cells in different ways: Fibronectin facilitates sliding of epithelium, whereas EGF increases cell proliferation.

Animals↗
PubMed1986

Nature of the enhancement of lecithin-cholesterol acyltransferase reaction by various apolipoproteins.

The effects of human apolipoproteins on the lecithin-cholesterol acyltransferase reaction were studied by using purified human lecithin-cholesterol acyltransferase and phosphatidylcholine-cholesterol vesicles. When the assay mixtures contained an optimal amount or excess of apo-A-I, the addition of apo-A-II, apo-C-II, apo-C-III1, or apo-C-III2 inhibited the enzymatic reaction. However, at suboptimal apo-A-I concentrations, the addition of low concentrations of these apolipoproteins exhibited activating effects. The relative activating effects were greater at lower apo-A-I levels. Under no circumstance did the combined activating effect of apo-A-I and other apolipoproteins exceed the maximum activating effect observed with the optimal level of apo-A-I alone. Since apo-A-II, apo-C-II, and apo-C-III did not show significant activating effects in the absence of apo-A-I, these apolipoproteins apparently did not act as true activator proteins for the enzymatic reaction. The activation of the enzymatic reaction by apo-A-I alone was shown to be due in part to the enhancement of the enzyme transfer between the substrate particles. The replacement of the transfer-enhancing effect of apo-A-I by apo-A-II, apo-C-II, or apo-C-III appears to be responsible for their apparent activating effects in the presence of suboptimal levels of apo-A-I. These apolipoproteins seemed to coexist with both the enzyme and apo-A-I on the substrate particles under the conditions when they showed the activating effect. However, at the concentrations inhibitory to the enzymatic reaction, these apolipoproteins displaced both the enzyme and apo-A-I from the phosphatidylcholine-cholesterol vesicles.

Apolipoprotein A-I↗
PubMed1986

Resolution of saccadic palsy after treatment of brain-stem metastasis.

A 65-year-old man was unable to generate normal horizontal saccadic eye movements. Smooth pursuit of sinusoidal target motion was normal. The saccadic palsy resolved rapidly, twice, after treatment with intravenous corticosteroids. Computed tomography showed a lesion in the pons, and seven months later he was found to have metastatic adenocarcinoma.

Adenocarcinoma↗
PubMed1986

Transformation of chenodeoxycholic acid to ursodeoxycholic acid in patients with Crohn's disease.

In vivo 7 beta-epimerization of chenodeoxycholic acid to ursodeoxycholic acid and the role of 7-ketolithocholic acid as an intermediate in this biotransformation were studied in 11 patients with Crohn's disease and in 5 healthy volunteers. The incorporation of deuterium into biliary ursodeoxycholic acid and 7-ketolithocholic acid was determined by computed gas chromatography-mass fragmentography after ingestion of a dideuterated chenodeoxycholic acid, chenodeoxycholic-11,12-d2 acid. The incorporation of deuterium into ursodeoxycholic acid increased to a peak level at 48 h in the patients with Crohn's disease, but was delayed in healthy volunteers. In 8 patients and 2 healthy controls there were small amounts of 7-ketolithocholic acid in bile. The incorporation of deuterium into 7-ketolithocholic acid was confirmed in only 2 patients and the peak level was noted at 48 h. These observations suggest that 7-ketolithocholic acid is an intermediate of this biotransformation in patients with Crohn's disease.

Adolescent↗
PubMed1986

Immunohistochemical demonstration of carcinoembryonic antigen (CEA) on tissue sections from squamous cell head and neck cancer and plasma CEA levels of the patients.

45 squamous cell head and neck cancers including 36 with carcinoma of the oral cavity and 9 with carcinoma of the maxillary sinus were examined immunohistochemically for the presence of CEA. 12 of 30 carcinomas of the oral cavity and 7 of the 9 carcinomas of the maxillary sinus had tumors containing CEA. This difference in the occurrence of CEA was statistically significant. The mean plasma CEA level of 36 patients with carcinoma of the oral cavity and 7 patients with carcinoma of the maxillary sinus was 1.95 +/- 1.72 ng/ml and 3.70 +/- 3.53 ng/ml, respectively. Significant elevation of plasma CEA levels was found only in the stage-IV group patients with carcinoma of the oral cavity as compared with the stage-I group patients. In the 3 patients having plasma CEA values exceeding 5 ng/ml at the time of pretherapy, plasma CEA levels were decreased to below 2.5 ng/ml with the cancer treatment followed by the complete remission. These findings indicate that plasma CEA as a tumor marker in squamous cell head and neck cancer is meaningful in a small proportion of the cancer patient population.

Aged↗
PubMed1986

Early cancer and related lesions in the bronchial epithelium in former workers of mustard gas factory.

The bronchial epithelium in stepwise transverse sections was examined histologically in 66 male autopsy cases, composed of the groups of 19 mustard gas (MG) ex-workers with lung cancer, 17 MG ex-workers with non-lung cancer, 10 non-MG lung cancer cases, and 20 non-MG non-lung cancer cases. Foci of moderate or severe atypical cellular lesion or dysplasia, or of carcinoma in situ (CIS) in total slides of each group, were counted as 146 in 3,485, 72 in 2,226, 70 in 3,797, and 18 in 4,611, respectively. The relative frequency of moderate or severe dysplasia and CIS in MG exposed non-lung cancer cases resembled that found in lung cancer cases of both MG and non-MG exposed. Seven CIS lesions were detected from among all MG-exposed cases and one CIS was found in a non-MG lung cancer case. Six out of eight CIS examples were adjoined by dysplasia. A multi-variate analysis revealed a significant correlation between the incidence of atypical lesions and MG exposure, though the incidence of atypical lesions was also influenced significantly by age, smoking, and chronic bronchitis. The incidence of atypical lesions was significantly higher in cases of squamous cell lung cancer than those of other histological types, particularly small cell cancer.

Adenocarcinoma↗