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Biomedical subjects

S Homma

Publications and source records attributed to S Homma.

At least 307 records · Page 17Linked to original sources

[Establishment and characterization of human pancreatic adenocarcinoma cell line JHP-1 producing carbohydrate antigen 19-9 and carcinoembryonic antigen].

A new tumor cell line derived from the ascites of a patient with adenocarcinoma of the head of pancreas was established in culture and the nude mouse. The cell line was characterized by the growth with a population doubling time of 22 hr., a high plating efficiency on the plastic surface and a modal chromosome number of 66. The tumorigenicity was proved by the growth in nude mouse and in soft agar. Morphologically the cell line grew as a confluent monolayer with tight adhesion to the plastic surface. Histologically the cell line was epithelial-like in culture and poorly differentiated adenocarcinoma in nude mouse. Ultrastructurally the cell line showed a characteristic pancreatic epithelium. Furthermore, the cell line expressed carbohydrate antigen 19-9 and carcinoembryonic antigen. This cell line, designated JHP-1, has been cultured for at least 100 passages in vitro and maintained for more than 2 years. This cell line would be used as a new model for human pancreatic carcinoma.

Adenocarcinoma↗

[Establishment and characterization of a human gall bladder carcinoma cell line NOZ].

A human gall bladder carcinoma cell line was established from ascites of a patient of peritonitis carcinomatosa. The pathological diagnosis of this patient was adenocarcinoma tubular ++, moderately differentiated. This cell line was composed of polygonal, spindle and round shaped cells. Each cell types were cloned by single cell cloning technique and each cloned cell secreted CEA or Ferritin or none of them. The doubling time of cell number was 48 hours, and plating efficiency was 14-19%. NOZ cell was transplantable to nude mouse. The morphological feature of transplanted tumor was similar to the original one.

Adenocarcinoma↗

Safety of intravenous dipyridamole for stress testing with thallium imaging.

Cardiac and noncardiac side effects were studied in 293 consecutive patients referred for nonexercise stress thallium imaging with intravenous dipyridamole. Six minutes after the initiation of infusion, there was a mean 9-beat/min increase in heart rate and a mean 12-mm Hg decrease in systolic blood pressure. The largest increase in heart rate exceeded 20 beats/min in only 13% of patients and the largest decrease in systolic blood pressure exceeded 20 mm Hg in 31%. Noncardiac side effects were headache (11%), lightheadedness or dizziness (5%) and nausea (4%). Only 9 patients required intravenous aminophylline for relief of noncardiac side effects: severe headache in 7 and nausea in 2. Cardiac side effects included chest pain in 76 patients (26%), of whom 70% were given aminophylline for relief of symptoms. Sixty patients (20%) had ischemic ST-segment depression and 56 (19%) had arrhythmias (ventricular in 50 and atrial in 6). There were no deaths, myocardial infarctions or sustained arrhythmias due to dipyridamole administration. Among 62 patients also undergoing cardiac catheterization, side effects except for arrhythmias were unrelated to the number of vessels with coronary artery disease. Intravenous dipyridamole is safe for nonexercise stress testing and has few serious side effects. However, the possibility of ischemia requires careful selection of patients and monitoring of vital signs and the electrocardiogram during the test.

Aged↗

The terminal distribution pattern of spinocerebellar fibers. An anterograde labelling study in the posthatching chick.

The terminal fields of spinocerebellar fibers from different levels (cervical, thoracic and lumbar) of the spinal cord in the chick were determined by using wheat germ agglutinin conjugated horseradish peroxidase (WGA-HRP), an anterograde labelling technique. More terminals were found in the anterior lobe than in the posterior lobe. Following injections in the lumbar spinal cord, mossy fiber terminals were found mostly in the anterior lobe (lobules I-V). The highest density of labelled terminals was found in lobule I, and labelled terminals were found in all parts of the lobule. However in lobules II-IV, labelled fibers were mediolaterally arranged in three longitudinal strips on both sides of the midline, and formed a distinct zonal distribution pattern. Labelled terminals were distributed evenly from the apical to basal regions of lobules I-V. A large number of mossy fiber terminals originating from the thoracic spinal cord were located in the anterior lobe and lobule VI; some labelled terminals were found in lobule IX. Three less distinct longitudinal strips, compared to those following WGA-HRP injections in the lumbar spinal cord, were recognized on each side of the midline. Labelled mossy terminals were observed in lobules II-IX following WGA-HRP injections in the cervical spinal cord. In transverse sections two longitudinal strips were found at the apical parts of lobules II and III, whereas four thin longitudinal strips were located in lobules IV and V. The present study showed that the terminal fields of spinocerebellar fibers from each level of the spinal cord have different distribution patterns.

Afferent Pathways↗

Human bile duct carcinoma cell line producing abundant mucin in vitro.

A human bile duct carcinoma cell line, designated OZ, was established from ascitic effusion of a patient who suffered from obstructive jaundice due to the clogging of the common bile duct with mucinous substances secreted by the cancer cells. OZ was found to be capable of producing mucin in vitro and pools of mucin were macroscopically identified on the monolayer of the cells. On the electron micrographs, cell coat type mucin and abundant intracytoplasmic desmosomes were observed. The OZ cells secreted carcinoembryonic antigen in culture and had high enzymatic activity of gamma-glutamyl transpeptidase. The tumor heterotransplanted into nude mice also showed mucin production.

Adenocarcinoma, Papillary↗

Dipole-tracing method applied to human brain potentials.

A new computer-aided method was developed to estimate the location of an electric source generator (e.g. a current dipole) in the human brain. Brain activity such as somatosensory evoked potentials was recorded with 21 surface electrodes over the scalp. To solve the inverse problem, it was assumed that only one dipole is elicited at a given time, and that the head is embedded in an infinite and homogeneous conductor. The exact geometry of the human head was measured from 17 slices of CT-images of a real head to arrange a human head model. A dipole with a given moment and location is assumed in the head model. Potential distribution elicited by the dipole is compared with potential distribution which was the actual recorded one. The optimal dipole location was calculated, using the simplex method. Hence, the optimal dipole moment was obtained. The accuracy of estimation as an equivalent dipole was expressed in terms of dipolarity.

Brain↗

Dynamics of NAD in cortical nephron segments: effect of nicotinamide and of dietary phosphate intake.

NAD content and the rate of NAD hydrolysis were determined in proximal convoluted tubules (PCT), proximal straight tubules (PST), and adjacent cortical nephron segments microdissected from kidneys of thyroparathyroidectomized (TPTX) rats. In the basal state, rats fed a normal phosphate diet had an NAD content higher in PCT, PST, and in cortical ascending limb (CAL) than in glomeruli. After intraperitoneal injection of nicotinamide, the NAD content increased significantly in all nephron segments except CAL; the greatest (delta + 277%) increase was found in PCT, with less (delta + 82%) in PST. In experiments conducted on TPTX rats stabilized on a low-phosphorus diet, NAD content increased in response to a nicotinamide injection in PCT (delta + 197%), but did not change significantly in PST. The catabolism of NAD was determined by generation of [3H]adenosine, a major metabolite of [adenine-2,8-3H]NAD. The rate of [3H]adenosine generation from [3H]NAD was significantly (P less than 0.001) higher in PST than in PCT. We conclude that, in response to nicotinamide administration in vivo, the NAD content increases more in PCT than in PST and that this difference may be, at least partly, due to a lower rate of NAD breakdown in PCT. In a state of dietary phosphate deprivation, NAD also increases significantly in response to intraperitoneal nicotinamide in PCT, but it does not increase significantly in PST. The nicotinamide-elicited increase of NAD content in proximal tubules, mainly in PCT, may be related to inhibition of Na+-gradient-dependent inorganic phosphate (Pi) reabsorption across the brush-border membrane of proximal tubules and to the phosphaturic effect of nicotinamide in rats fed normal-Pi diet.

Animals↗

Differential distribution of synaptic terminals on intracellularly marked giant interneurons of the lamprey, Lampetra japonica.

Differential distribution of synaptic terminals on the soma and dendrites of lamprey (Lampetra japonica) giant interneurons were investigated with electron microscope after marking them intracellularly with Procion scarlet. Synaptic terminals were classified by the morphology of their synaptic vesicles as S (spherical) or F (flat). The ratio of F-terminals to S-terminals (F/S) on the somata was 2.62 from 5 neurons (number of terminals observed, n = 527), and that on the dendrites from 3 neurons was 0.71 (n = 348). The physiological meanings of differential distribution of synaptic terminals were discussed.

Animals↗

Cross-correlation analysis of neuronal activities.

Nerve impulses are generally regarded as spike train and analyzed by use of various kinds of so-called time series analyses. Cross-correlation analysis is used to reveal temporal and/or spatial relationships between more than two spike trains in the neuronal circuit, in which two neurons are synaptically connected or two neurons are independent but receive a common input. Three main characteristics of discharge dependency between two neurons become clear from the cross-correlation histogram: 1) the direction of dependency; 2) the latency of interaction; and 3) the type of functional connections between the neurons. We reviewed the cross-correlation analysis from these points of view: 1) what is cross-correlation analysis; 2) what are primary and secondary effects; 3) what kinds of functional information can be obtained from the shape of the primary effect; 4) how sensitively cross-correlation can detect neuronal interaction; 5) how to express quantitatively the primary effect; 6) what kinds of extension technique are available from cross-correlation; and 7) research trends using cross-correlation analysis.

Animals↗

Triacylglycerol composition of winged bean (Psophocarpus tetragonolobus).

Winged beans were extracted with hexane and the extracted lipid was analyzed by HPLC for its triacylglycerol (triglyceride) composition on a Lichrosorb RP-18 column with acetonitrile-tetrahydrofuran-dichloromethane (6:2:1) solvent mixtures. The chromatography yielded more than 21 peaks, and each triacylglycerol was analyzed for fatty acids by GLC. The major triacylglycerols were found to be behenoyl-linoleoyl-oleoylglycerol (21.3%), trioleoylglycerol (10.5%) and behenoyl-dioleoylglycerol (15.6%). Winged bean oil was found to contain triacylglycerols of larger ECN (equivalent carbon number) than soybean oil.

Chromatography, High Pressure Liquid↗

Correlates of lung/heart ratio of thallium-201 in coronary artery disease.

We studied 306 patients with chest pain (262 with coronary artery disease and 44 with no coronary artery disease) to determine which of 23 clinical, exercise, thallium, and angiographic variables best discriminate between patients with increased lung/heart ratios of thallium versus those with normal ratios. Normal lung/heart ratio values were defined using an additional 45 subjects with less than 1% probability of coronary artery disease. The number of diseased vessels was the best discriminator between patients with increased ratios versus those with normal ratios. Double product at peak exercise, number of segments with abnormal wall motion, patient gender, and duration of exercise were also significant discriminators. Using discriminant function analysis these variables could correctly identify 81% of cases with increased lung/heart ratios and 72% of cases with normal ratios. These results indicate that an increased lung/heart ratio of thallium reflects exercise-induced left ventricular dysfunction and affords a better understanding of why this thallium parameter is a powerful prognostic indicator in patients with chest pain.

Adult↗