Search PubMed⌕ Search

Biomedical subjects

N Baba

Publications and source records attributed to N Baba.

At least 145 records · Page 8Linked to original sources
PubMed1986

The structure analysis of Hirano bodies by digital processing on electron micrographs.

To clarify the structure of Hirano bodies, electron micrographs of Hirano bodies taken at various tilting angles have been studied by digital image analysis. On the electron micrographs, the beaded filaments of Hirano bodies were turned into a pattern of lattice-like arrays by changing the tilting angles. Based on computer-processed diffraction patterns and filtered images, it is proposed that the filaments of Hirano bodies are helical strands with a pitch of 185 A. A model for the helical strand drawn by microcomputer at various angles of rotation is in accordance with the filtered images of the tilted filaments. Computer simulation also reveals that the helical strands appear to be lattice-like when they are arranged in parallel.

Dementia↗
PubMed1986

Influence of obstructive jaundice on pancreatic growth and on basal plasma levels of cholecystokinin and gastrin in rats.

Obstructive jaundice was produced in rats by ligation and transection of bile duct outside the liver; the control group underwent laparotomy alone. Pancreatic wet weight, amylase, lipase, protein, DNA, RNA, RNA/DNA ratio, and weight/100 micrograms DNA were significantly increased in jaundiced rats when compared to control rats. Histologic evaluation of pancreatic tissue obtained from jaundiced rats revealed the appearance of large or multiple nuclei in pancreatic acinar cells. Basal plasma levels of immunoreactive CCK were significantly increased in jaundiced rats at two weeks and four weeks but, when compared to the levels obtained in laparotomized controls at those time intervals, CCK levels were not significantly different. In jaundiced rats, plasma immunoreactive gastrin was found to be significantly decreased at two and four weeks. Plasma gastrin levels were also found significantly decreased when the jaundiced group was compared with laparotomized control group. The results suggest that obstructive jaundice induced enlargement of the pancreas, probably due to hyperplasia and hypertrophy of pancreatic cells. Whether or not this phenomenon is related to changes in gastrin and CCK is not known.

Amylases↗
PubMed1986

Evolution of a hereditary cardiac conduction and muscle disorder: a study involving a family with six generations affected.

This study describes six generations of a family with autosomal dominant cardiac conduction system and myocardial disease with recognizable clinical stages. A 20 year follow-up of nine family members, a medical questionnaire of 196, electrocardiographic screening of 91, noninvasive testing of 20, and catheterization with endomyocardial biopsy of six are the basis of this report. The clinical stages are as follows: Stage I occurs in the second and third decades of life and is characterized by an absence of symptoms, normal heart size, sinus bradycardia, and premature atrial contractions. Stage II is marked by first-degree atrioventricular block in the third and fourth decades. Stage III occurs in the fourth and fifth decades and is accompanied by chest pain, fatigue, lightheadedness, and advanced atrioventricular block followed by the development of atrial fibrillation or flutter. Stage IV, in the fifth and sixth decades of life, is characterized by congestive heart failure and recurrent ventricular arrhythmias. Light microscopy of right ventricular endomyocardial biopsy specimens from patients in stage II revealed very mild fibrosis; electron microscopy of the specimens demonstrated mild dilatation of tubules, mitochondrial swelling, and minimal myofibrillar loss. Biopsy specimens from patients with stage III disease were similar to those from patients with stage II disease except for an increase of myofibrillar loss. The stage IV specimens had diffuse fibrosis and more severe tubular dilatation, mitochondrial cristolysis, and myofibrillar loss. At autopsy in the proband, the atrial changes were more severe than the ventricular and were especially marked in the sinoatrial and atrial myocardium. Early recognition of the disease and use of pacemakers and antiarrhythmic agents have proved beneficial for affected family members. Thorough family studies of patients with conduction system disease and/or dilated cardiomyopathy are necessary to better understand the hereditary basis and natural course of this category of disease.

Adolescent↗
PubMed1985

The morphology of L-fucose, D-mannose specific lectin (SFL 100-2) produced by Streptomyces No. 100-2.

The morphology of an L-fucose specific lectin, SEL 100-2, from a Streptomyces sp. was studied. Electron microscopic observation showed that purified SFL 100-2 preparation consisted of particles homogeneous in size. The diameter was 25 nm. The digitized images of these particles had 2-fold rotation symmetry. The sedimentation coefficient (s020,w) was determined to be 20.6S. The particle weight and the Stokes radius were calculated to be 8.0 X 10(5) daltons and 94 A, respectively, by three independent methods, i.e., gel filtration, sedimentation equilibrium and velocity measurements. The frictional ratio (f/fmin) was estimated to be 1.53. These values are quite similar to those of human alpha 2-macroglobulin. 125I-Labeled peptide mapping indicated that these particles were built up of about twelve identical subunits (Mr = 68,000). The size of SFL 100-2 in culture broth was found to be the same as that of the particles in the purified preparations. The shape and other properties of SFL 100-2 are discussed and compared with those of the tail of lambda phage and type 1 pili of Escherichia coli, whose amino acid compositions were quite similar to that of SFL 100-2 and also those of L-fucose specific plant lectins.

Autoradiography↗
PubMed1984

Effects of trypsin inhibitor on the remnant pancreas after 85 percent pancreatectomy in rats.

Major resection of the pancreas leads to disorders of the endocrine and exocrine pancreas. The effect of a trypsin inhibitor on the remnant pancreas was studied in rats after 85 percent pancreatectomy. Impairments of the glucose elimination rate and the integrated insulin response after 85 percent pancreatectomy were improved by means of oral administration of a synthetic trypsin inhibitor for 4 and 12 weeks. The pancreatic insulin content in the animals treated with trypsin inhibitor for 13 weeks increased to about 1.3 times than that obtained in control animals. The exocrine pancreatic function in 85 percent pancreatectomized rats treated with trypsin inhibitor for 4 weeks and 12 weeks showed substantial improvement as shown by the test with N-benzoyl-L-tyrosil-p-aminobenzoic acid (BT-PABA). The pancreatic amylase, lipase, and protein contents in the animals treated with trypsin inhibitor were increased to 1.9, 1.7 and 2.1-fold, respectively, as compared to control animals for 13 weeks. Histologic examination showed a decrease in abnormal islets of Langerhans, and a tendency toward hypertrophy of the acinar cells. These results suggest that oral administration of a trypsin inhibitor to rats is effective in improving pancreatic endocrine and exocrine functions after 85 percent pancreatectomy.

4-Aminobenzoic Acid↗
PubMed1984

Alveolar soft part sarcoma. An elaboration of a three-dimensional configuration of the crystalloids by digital image processing.

As an initial step to elucidate the nature of the unique characteristics of the crystalloids of alveolar soft part sarcoma, a three-dimensional model of the crystalloids was prepared by digital image analysis of electron micrographs by computer. It was revealed that occult periodicities are present at two intervals, 60 A and 380 A, in the filamentous structure of the crystalloid; and it was also revealed by the observation of each cross-section that two globular substances with a diameter of 60 A are arranged in a dumbbell pattern in each filamentous structure. The model prepared based on these data showed the double strands crossing each other at intervals of 380 A, each of which consists of successive arrangement of the globular substances with a diameter of 60 A. This structure is clearly similar to that of actin. The similarities and differences between these results and the well-known studies of the organization of naturally occurring actin bundles are discussed.

Adult↗
PubMed1982

The pattern of myocardial degeneration in nonischemic congestive cardiomyopathy.

The histopathologic features of nonischemic congestive cardiomyopathy (CCM) include diffuse and focal fibrosis, vacuolar degeneration, and myofiber hypertrophy. Eleven patients with CCM and five controls were studied. Fibrosis and degree of vacuolization were quantified by means of stereologic techniques; myocardial cell diameter was measured with an ocular micrometer. Five levels of the left ventricular free wall were examined. Area I was immediately subepicardial, and area 5 was immediately subendocardial. In all areas, fibrosis, vacuolization, and fiber diameter were significantly greater in the experimental group than in the control group (P less than 0.05). In addition, fibrosis and vacuolization had an umbrella distribution, which peaked in area 4, the area adjacent to the subendocardium (P less than 0.01). The distributions of fibrosis and vacuolar degeneration suggest compromised blood flow to the inner myocardial layers, with relative sparing of the immediate subendocardial region owing to its proximity to the left ventricular cavity.

Adult↗
PubMed1982

Enhanced thermogenesis and diminished deposition of fat in response to overfeeding with diet containing medium chain triglyceride.

The mechanism whereby overfeeding with diet containing medium chain triglyceride (MCT) results in diminished body weight and fat was studied. Fifteen male Sprague-Dawley rats were fitted under anesthesia with gastrostomy tubes and divided into two groups. One group was fed MCT diet, the other an isocaloric diet containing long chain triglyceride (LCT) in excess (150%) of spontaneous calorie intake. Both diets, fed for 6 wk, derived 50% of calories from fat. Basal and norepinephrine (25 micrograms/100 g) stimulated 02 consumption and CO2 production, as well as metabolic rate were measured. After the rats were killed, total dissectible fat and fat cell size and number were determined. MCT rats gained 15% less weight than LCT controls (p less than 0.001). Total dissectible fat was significantly lower (p less than 0.001) in MCT group, as was mean adipocyte size (p less than 0.001). Resting and maximal norepinephrine-stimulated 02 consumptions were 39.7 and 22.1% higher in MCT than in LCT group, respectively. Resting and norepinephrine-stimulated metabolic rates were 38.8 and 22.2% higher in MCT than LCT fed rats, respectively. Overfeeding MCT diet results in decreased body fat related to increased metabolic rate and thermogenesis.

Adipose Tissue↗
PubMed1982

Digital processing methods for structural analysis of an electron micrograph.

Digital processing method using the scanning-densitometer with microcomputer provides a useful description system. It draws attention to the usefulness of local lattice averaging in clarifying images of periodic structures in crystals as well as crystalloids and para crystalline arrays in biological specimens. Digital processing of lattice images in crystal structures from the selected diffraction spots is successfully developed to the structural analysis of evaporated gold, graphitized carbon and human tooth enamel of hydroxyapatite. Furthermore, known microbody crystalloids in enzyme and icosahedral capsids in virus are confirmed and clarified by the procedure of selecting diffraction spectra transformed from the information taken with high resolution electron micrographs. The processed results can provide significant improvements in structural analysis of an electron micrograph.

Crystallography↗