Biomedical subjects

T Shibata

Publications and source records attributed to T Shibata.

At least 739 records · Page 41Linked to original sources

PubMed1990

Proliferative potential of murine melanoma cells cultured in or on collagen gel.

As the first step in developing an in vitro model of melanoma cells infiltrating the dermis, B16 murine melanoma cells were cultured on and in type I collagen gels. Under these conditions, the melanoma cell adopted an elongated or dendritic form. Cell proliferation was suppressed in the culture system using the collagen gel as compared with the conventional monolayer culture on plastic. Microcinematographically, this suppression was found to be due to an extension of the cell cycle time of each individual cell. On the other hand, there were no appreciable differences in proliferation pattern between the cells cultured on type I and IV collagen film and those cultured on plastic. These results suggest that there are interactions between type I collagen in the gel form and melanoma cells, especially with respect to cell growth.

Animals↗

PubMed1990

The role of bone fracture at the site of carcinogen exposure on nickel carcinogenesis in the soft tissue.

The influence upon nickel subsulfide (alpha-Ni3S2; Ni-SS)-induced carcinogenesis in the soft tissue of bone fracture at the site of Ni-SS exposure was studied using female Fischer rats. During the one year of the experiment, the group subjected to bone fracture exhibited the shortest tumor induction time and survival time, and a significantly higher metastatic rate. The present study may suggest a model for the metastasis of human soft tissue tumors.

Animals↗

PubMed1990

In vitro IgG rheumatoid factor production by CD5-negative murine B cells in response to immune complexes of lipopolysaccharide.

We studied the in vitro production of rheumatoid factor (RF) by spleen cells of normal adult mice. IgG RF cross-reactive with rabbit IgG was produced in response to immune complexes of TNP-lipopolysaccharide (LPS) with murine IgG anti-TNP antibody in an Fc-specific manner, but not to a mixture of IgG and LPS. Antibody-uncomplexed LPS induced little IgG RF production, but suppressed the subsequent IgG RF response to antibody-complexed LPS, whereas IgM RF was induced by either LPS or antibody-complexed LPS. The IgG RF production followed as rapid a time course as IgM RF production; the rate of IgG RF production reached its maximum soon after a lag period of 1 day and declined after 5 days. Treatment of splenic B cells from BALB/c mice with anti-Ly-1.2 antibody and rabbit complement resulted in a selective reduction of IgM RF production by 90%, with little effect of IgG RF production. These results suggest that IgG RF is derived primarily from CD5- memory B cells which have been developed in normal mice by an unknown mechanism. Unlike the CD5+ precursor cells for IgM RF, these memory cells are unresponsive to polyclonal stimulation by LPS but are activated by simultaneous stimulation by aggregated Fc epitopes and the mitogenic stimulus from LPS.

Animals↗

PubMed1990

IgG isotype and isotype specificity of murine monoclonal IgG rheumatoid factors.

Immune complexes of lipopolysaccharide (LPS) with homologous IgG antibody induces rheumatoid factor (RF) predominantly of the IgG class in normal mice, while LPS alone induces mostly IgM RF directed to homologous IgG1. In this study, IgG monoclonal RFs (mRF) were prepared from hybridomas derived from spleen cells of BALB/c mice which were immunized with complexes of TNP-LPS with anti-TNP mouse IgG and their specificity to mouse IgG subclasses was assessed by analysing dissociation kinetics of the ligands due to RF-specific and non-specific interactions. Of the 19 IgG mRFs (11 IgG1, five IgG2a, one IgG2b and two IgG3 types) tested, 14 were directed to either IgG3 or IgG2b or both, while only one exhibited a significant binding capacity to IgG1. Other mRFs, although reactive to rabbit IgG, exhibited little homophilic activity. None of these mRFs reacted strongly with their own isotypes. The results suggest that the IgG RF producing cells are not direct progenies of the IgG1-directed IgM RF-producing cells but may have developed via a rigorous selection process to eliminate clones that produce self-reactive RF.

Animals↗

PubMed1990

A case of lipoprotein glomerulopathy. Light and electron microscopic observations of the glomerulus.

A 41-year-old Japanese woman with lipoprotein glomerulopathy is reported. The patient presented with nephrotic syndrome, hyperlipoproteinemia and an increased level of plasma Apo E. The damaged glomeruli showed various degrees of capillary dilatation and accumulation of some material-often showing stratification, along with mesangial proliferation and mesangial interposition. The accumulated material was stained positive for beta-lipoprotein by the indirect immunoperoxidase technique. Capillary dilatation resulted from gradual accumulation of the lipoprotein as well as destruction of the mesangium, as if being torn off, due to increased intraluminal pressure. The patient's eldest sister also suffers from the same renal disease, suggesting a hereditary predisposition.

Adult↗

PubMed1990

Gallbladder carcinoma: evaluation with MR imaging.

Magnetic resonance (MR) images of 19 patients with histologically proved gallbladder carcinoma were retrospectively reviewed to determine the appearance of the primary tumor, and to assess the ability of MR imaging to demonstrate the various modes of tumor spread beyond the gallbladder. The primary tumor, as well as tumor spread beyond the gallbladder, was hyperintense on T2-weighted images and hypointense on T1-weighted images when compared with the liver parenchyma. Liver invasion and metastasis could be depicted by MR imaging with both sequences, unless the tumors were small or the extent of invasion was minimal. Duodenal invasion was difficult to evaluate because of motion artifacts, paucity of fat, and partial volume effects. T1-weighted images readily demonstrated extension of the tumor to the hepatoduodenal ligament and para-aortic region with good contrast between tumor and surrounding tissue. The extent of tumor extension to the blood vessels was also easily evaluated because of flow void in the vasculature. MR imaging can help determine the extent of gallbladder carcinoma and can contribute to the staging of this disease.

Adenocarcinoma↗

PubMed1990

Metabolic and functional consequences of barium-induced contracture in rabbit myocardium.

Barium contracture tonically activates myocardium while preserving cellular integrity. We studied the metabolic and mechanical consequences of sustained Ba2+ contracture. We measured the time course of phosphocreatine (PCr), ATP, Pi, total phosphate, and intracellular pH via 31P nuclear magnetic resonance (NMR) in isolated, isovolumic rabbit hearts. For mechanical studies, we measured force transients and dynamic stiffness in excised rabbit right ventricular papillary muscles at different elapsed times in Ba2+ contracture. In the perfused hearts, PCr fell steadily to 20% of control after 60 min. ATP remained constant for approximately 25 min then fell to 25% by 60 min. Pi rose to 200% within 15 min and then remained unchanged, whereas total phosphate dropped steadily to 50% of control by 60 min. Myocardial O2 consumption remained near control for 30 min and then declined to 50% by 60 min. Consistent with ATP and O2 consumption measurements, mechanical responses were unchanged for approximately the first half hour. Because of the elevated Pi, however, myofilament kinetics may have been accelerated compared with the control metabolic state. After the initial period of stable contracture, the gradual alteration of mechanical behavior exhibited a progressive trend toward more rigor-like characteristics. In summary, myocardium in Ba2+ contracture is metabolically and mechanically stable for approximately 30 min but begins to degrade thereafter. When compared with other tonic states of activation, Ba2+ contracture appears to be less demanding energetically.

Animals↗

PubMed1990

Stimulatory effects of bombesin on plasma trypsin release and exocrine pancreatic secretion in dogs.

We examined the effect of bombesin on plasma trypsin release and exocrine pancreatic secretion in dogs. Bombesin significantly increased plasma immunoreactive trypsin (IRT). Atropine significantly inhibited the response of plasma IRT to bombesin. Pancreatic trypsin secretion was also increased by bombesin, as well as bicarbonate and protein outputs. Atropine failed to inhibit pancreatic trypsin secretion. In conclusion, bombesin has a stimulatory effect on plasma trypsin release mediated by a cholinergic mechanism and different from pancreatic secretion.

Amylases↗

PubMed1990

The multi-purpose camera: a new anterior eye segment analysis system.

A new device for the analysis of the anterior eye segment was developed. With this device, a Scheimpflug slit image and a retroillumination image can be taken separately using a CCD camera. The quality of the images obtained was satisfactory enough for analysis. The data obtained were stored and analyzed on an almost real-time level using an on-line computer. The menu for the data analysis provided for this device includes multilinear densitometry, with planimetry, area densitometry, measurement of anterior chamber depth and thickness of lens layers, determination of chamber angle and positioning of implanted intraocular lenses, and measurement of opaque areas in the retroillumination image.

Animals↗

PubMed1990

Classification system for cataracts. Application by the Japanese Cooperative Cataract Epidemiology Study Group.

A cataract classification and grading system for the main purpose of cataract epidemiological studies is proposed by the Japanese Cooperative Cataract Epidemiology Study Group. Cataractous types are classified principally into cortical, nuclear and subcapsular opacities. Stages of cataract advancement are classified into grade I (early stage), grade II (moderate stage) and grade III (advanced stage). Regarding cortical opacities an opacified area obtained from red-reflex images is utilized for grading judgment. Nuclear opacity grading is based on the intensity of scattering at the nucleus. Grading of subcapsular opacities is judged from their extension in the three different pupillary areas. To help grading judgments, standard pictures of cortical and nuclear cataracts are provided. Gradings of lens coloration are divided into pale yellow (grade I), yellow (II), brownish yellow (III) and brown including reddish and black brown (IV). A recording chart is also provided.

Adult↗

PubMed1990

Quantitative chamber angle measurement utilizing image-processing techniques.

An image-processing technique was applied to the measurement of the anterior chamber angle. The anterior eye segment was documented by a new instrument, named anterior eye segment analysis system for biometry of the anterior eye segment. The approximated curve of the corneal posterior curvature and the line tangent to the anterior surface of the iris were calculated as the anterior chamber angle. The mean error of the reproducibility of repeated measurements for the same image was 1.6 +/- 0.81% and that of 3 images of the same eye which were taken at 3 different times was within 5.2%.

Adult↗

PubMed1990

Body surface mapping of high-frequency components in the terminal portion during QRS complex for the prediction of ventricular tachycardia in patients with previous myocardial infarction.

To study the clinical significance of terminal QRS high-frequency components for the prediction of ventricular tachycardia, an 87-lead body surface signal-averaged mapping was performed in 21 healthy subjects (control) and in 41 patients with previous myocardial infarction (anterior, 20; inferior, 21). Mapping data were analyzed and averaged (129.7 +/- 26.5 beats) for 160 seconds, and the signal-averaged beat was filtered with a bidirectional bandwidth (80-250 Hz) digital filter. J-point was determined from the 87-lead RMS voltage of nonfiltered QRS. For each lead, we calculated the sum of the absolute value of filtered QRS from 20 msec ahead of the J-point to the J-point (A-20). The body surface distribution of A-20 was expressed as A-20 map. The maxima in A-20 maps were mainly located on the upper sternal region in healthy subjects, on the left anterior chest in patients with previous anterior myocardial infarction, and on the central anterior chest in patients with previous inferior myocardial infarction. In the patients in both the group with anterior myocardial infarction and the group with inferior myocardial infarction, the value of maximum was significantly greater than in the subjects in the control group (0.181 +/- 0.086 and 0.138 +/- 0.048, respectively, vs. 0.075 +/- 0.031 mV.msec; p less than 0.01). In patients with myocardial infarction (n = 41), the value of maximum was significantly greater with ventricular tachycardia (n = 11) than without ventricular tachycardia (n = 30) (0.240 +/- 0.076 vs. 0.130 +/- 0.043 mV.msec; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

[Work load of nursery teachers in a nursery school. Relationship between age of children and work load].

Time study of six nursery teachers of children aged 0 to 5 was conducted at a public nursery school to ascertain their work load, and the results obtained were examined from the following two viewpoints. First, comparison was made between the results obtained by the following two methods of analysis; 1) An observer recorded the work contents and the working postures of a nursery teacher at place of work in one-minute units. 2) The nursery teacher was recorded on video tape and the analysis of the work contents and the working postures was made in one-second units. Second, comparison was made between the work loads (work content, working posture, walking, lifting children and recess) of nursery teachers of children of different age group. The results could be summarized as follows: 1. The results of analysis made by the two methods of the work contents and the working postures were in good agreement. 2. The higher the age of children in the class, the longer was the cumulative time for "indoor group nurture" and the shorter was the cumulative time for "help and care for feeding", "help and care for afternoon nap" and "help and care for excretion". 3. The higher the age of children in the class, the longer was the cumulative time of "standing" in a nursery teacher and the shorter was the cumulative time of "sitting on the floor". The total time of "bending forward", "squatting" and "rising on the knee" occupied 20% of the working hours on an average and was not related clearly to the age of children. 4. The frequency of walking was not found to be related to the age of children. 5. The nursery teachers of children aged 0 and 1 lifted children much more frequently among all nursery teachers. 6. The recess away from children was rarely observed throughout the day.

Age Factors↗

PubMed1990

Do the cardiac glands exist? 5. The dog.

The authors performed histological and histochemical investigations on the so-called cardiac glands and gastric glands of the dog, and compared the data on these glands. The conclusions were as follows: 1. The so-called cardiac glands have a number of parietal cells and cells distributed in the same glandular base contain fine pepsinogen granules. However, these glandular cells are filled with a PAS-positive substance. Accordingly, the so-called cardiac glands are nothing but undifferentiated gastric glands. 2. Due to the deep gastric pits, the outer layer of the mucous membrane in the clear zone is loose, and a distribution of a smaller number of blood vessels can be expected. These facts may demonstrate a pale or clear appearance of the mucous membrane in the same zone. 3. The gastric pits in the dark zone are extremely shallow. Accordingly, the mucous membrane in this area is dense and a distribution of a large number of blood vessels can be expected. This probably produces a dark color, i.e., reddish brown. 4. The chief cells in the glandular base of the clear zone contain a number of fine and coarse PAS-positive granules. These granules also are a violet color with PAS-AB (pH 2.5) stain. This color resulted from sialomucin. The above mentioned facts mean that the clear zone is an undifferentiated region of the gastric glands. 5. The chief cells distributed in the glandular body and base of the dark zone are PAS-negative and contain no sialomucin. Accordingly, the same zone is the differentiated region of the gastric glands.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Do the cardiac glands exist? 6. The cat.

We performed histological and histochemical investigations on so-called cardiac glands and gastric glands in the cat to clarify the existence of the former. 1. Cardiac glands possess some parietal cells and strongly PAS-positive glandular cells in the base of glands containing a small number of fine pepsinogen granules. Consequently, we consider them to be undifferentiated gastric glands. Therefore, the cardiac glands do not exist in the cat. 2. Glandular cells in the basal part of undifferentiated gastric glands react negatively or very weakly to AB (pH 2.5 and 0.5) and present a red color with PAS-AB (pH 2.5) stain. 3. A large number of strongly PAS-positive and pepsinogen granule containing cells are distributed not only in the glandular body but also in the basal part of the glands. These cells are immature chief cells. 4. The above-mentioned cells react weakly or moderately to AB (pH 2.5 and 0.5) and stain light purple by PAS-AB (pH 2.5). They possess weak and strong acid mucopolysaccharides and sialomucin. 5. Mature chief cells are distributed mainly in the glandular base. They are PAS-negative, react moderately or strongly to AB (pH 2.5 and 0.5), and present a dark color of AB with PAS-AB (pH 2.5) stain. Consequently, it can be concluded that these cells contain weak and strong acid mucopolysaccharides but no sialomucin. 6. Mature chief cells possess no sialomucin. However, they present stronger reactions to AB (pH 2.5 and 0.5) than those in immature chief cells. This characteristic does not appear in man and many other types of mammals studied.

Animals↗

PubMed1990

Fluid-path in the mandible and maxilla.

We examined fluid-paths in the maxilla and mandible of the dog, and compared them with Kihara's extravascular fluid-path-system. Areolar tissue is formed in the walls of the Volkmann's and Haversian canals. This tissue is composed of collagenous and reticular fibers. Kihara confirmed the collagenous fibers were encircled, however we could not ascertain whether they were encircled or not. We have compared the paths in the walls of the Volkmann's and Haversian canals with Kihara's fluid paths, and found the paths in the bone do not belong to the category of Kihara's paths. Namely, the term "extravascular fluid path" should not be applied to the areolar tissue in the bone. We suggest the term "fluid path" for this tissue in the bone. The areolar tissue in the walls of the Volkmann's and Haversian canals and endosteum communicate with one another. We call them collectively endosteum. Yoshikawa called the areolar tissue in the Volkmann's and Haversian canals perivasculäre lymsphräume. However, this designation is inadequate considering the actual characteristics of this tissue.

Animals↗

PubMed1990

Comparative histology and histochemistry of the gastric glands of cats and dogs.

We performed histological and histochemical investigations on the gastric glands of cats and dogs. So-called cardiac glands in the cat and dog have a small number of the parietal cells and the PAS-positive glandular cells in the base of these glands contain fine pepsinogen granules. Consequently, we consider them as undifferentiated gastric glands, and can find no differences between these glands in both animals. The immature chief cells in the cat gastric glands are distributed not only in the glandular body but also in the base of the glands and contain sialomucin, and weak and strong acid mucopolysaccharides. The mature chief cells in cat and dog gastric glands contain weak and strong acid mucopolysaccharides. The gastric gland region of the dog is divided into clear and dark zones, and structural differences between the two zones are recognizable. Namely, the chief cells in the glandular base in the clear zone are somewhat undifferentiated, while the chief cells in the middle and lower parts of the glandular body and those in the glandular base in the dark zone are perfectly differentiated. The structure of the gastric glands in the fundic and greater and lesser curvature regions in the cat is very similar.

Animals↗

PubMed1990

Do the cardiac glands exist? 7. The cow.

The glands distributed in the narrow region of the abomasum contiguous to the omasum of the cow have been described as cardiac glands. We doubted this assertion and therefore performed histological and histochemical investigations of the glands to clarify their characteristics. 1. All glandular cells except the parietal cells in a few glands contiguous to the omasum react strongly to PAS, AB(pH 2.5), and PAS-AB(pH 2.5) staining, and moderately to AB(pH 0.5) staining. 2. Glandular cells at the base of these glands contain fine pepsinogen granules and a few parietal cells are distributed in these glands, indicating that they are undifferentiated gastric glands and that the so-called cardiac glands do not exist in the cow stomach. 3. Glandular cells in undifferentiated gastric glands are filled with PAS, AB(pH 2.5 and 0.5) and PAS-AB(pH 2.5) positive substances. Which gradually decrease and finally disappear with differentiation, remaining only in the neck (mucous neck cells) and the cells in the upper part of the glandular body (immature chief cells), in mature gastric glands. 4. Mature chief cells in differentiated gastric glands are distributed in the middle and lower bodies and base of the glands and contain a number of PAS and PAS-AB(pH 2.5) positive granules and a large number of coarse pepsinogen granules, while pepsinogen granules in the mucous neck cells and immature chief cells are finer. 5. In the cow the region in which undifferentiated gastric glands are located is very narrow. 6. Parietal cells in the cow stomach are numerous.(ABSTRACT TRUNCATED AT 250 WORDS)

Abomasum↗