Biomedical subjects
Publications and source records attributed to T Katoh.
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In 11 patients with chronic pancreatitis without dilation of the main pancreatic duct, 4 had segmental lesions of the pancreas and 7 had diffuse lesions of the pancreas. Patients with the segmental lesion had a relatively good pancreatic function and were relieved from pain by surgical treatment for the segmental lesion. On the other hand, patients with the diffuse lesion had far advanced dysfunction of the pancreas and were not improved by drainage operation of the pancreatic duct. For such cases, total or near total pancreatectomy has been indicated to relieve pain at the price of creating insulin dependent diabetes. To control pain and to reserve pancreatic function as long as possible in these cases, we performed the resection of all the pancreatic nervous plexus for such 3 patients and have obtained good results, although follow-up periods are still short. This new approach may offer a means of relieving pain with preservation of endocrine function in selected patients with chronic pancreatitis, especially in patients who have not dilated pancreatic duct.
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Twenty-eight patients with various types of pituitary adenomas were studied endocrinologically and neuroradiologically. We observed the changes of tumor size during bromocriptine treatment. After various periods of bromocriptine therapy, we operated on these tumors and examined then histologically. One of 5 patients with nonfunctioning adenomas improved remarkably in his visual field and acuity after 7-month bromocriptine therapy. The pathological findings disclosed remarkable changes in tumors composed of shrunken island-like cell nests and acellular spaces. These shrunken island-like cell nests were composed of tumor cells whose cytoplasmic volume decreased and whose nuclear chromatin clumped. In acellular spaces, there were irreversibly destructed tumor cells, hyaline substances, tumor cell debris and collagen fibrils. One of 8 cases of acromegalies showed a remarkably reduced tumor on CT with clinical improvement after treatment with bromocriptine for 10 months. This patient's serum growth hormone titer was raised by an abnormal response to intravenously injected TRH (thyrotropin releasing hormone), and his serum prolactin was abnormally high. Therefore, this tumor was thought to be a mixed adenoma with growth hormone secreting and/or prolactin secreting cells. Histological examinations disclosed cell shrinkage of tumor cells. Interestingly, there were scanty fibrotic changes in this tumor in spite of the long term bromocriptine therapy. In 15 cases of prolactinomas, the larger the tumor size and the longer the period of the bromocriptine therapy, the more fibrosis was seen. Under a period of bromocriptine therapy longer than 3 months, the fibrotic changes of tumor progressed, and this made more difficulty in selective adenomectomy even in the case of intrasellar adenomas. Therefore we thought that transsphenoidal surgery could successfully be done within 3 months during continuation of bromocriptine therapy.
Human T-cell leukemia/lymphoma virus I (HTLV-I) is known to be associated with adult T-cell leukemia/lymphoma (ATL) as an etiological agent. The mechanism of leukemogenesis by HTLV, however, is still obscure. Two hypotheses have been proposed concerning abnormalities in IL-2 production and its receptor (Tac antigen) expression based on the experimental observations of IL-2-dependent ATL cell lines. In this study, we examine these hypotheses by using 3 leukemic T-cell lines from 3 Japanese patients with ATL. These cell lines were cultivated and established without addition of IL-2 to the culture medium. Cell-surface phenotype analysis by immunofluorescence with monoclonal antibodies (MAbs) and IL-2 binding assays revealed that one of the ATL cell lines, HPB-ATL-2, expresses only a minimal amount of IL-2 receptor (IL-2-R) on the cell surface and binds less radiolabelled human recombinant IL-2 than the other highly Tac-positive cell lines. Expression of Tac antigen in all ATL cell lines was not affected by IL-2, anti-Tac MAb or the tumor-promoter phorbol ester in the culture medium. The culture supernatant from these cell lines showed no IL-2 activity toward Con-A-stimulated human peripheral blood lymphocytes, and their growth was not affected by additional IL-2 in cultures. IL-2-independent growth and constitutive expression of its receptors on the cell surface were evident in our ATL cell lines. However, dense expression of IL-2 receptors was not essential for stimulation of leukemic proliferation of T cells by HTLV-I. Trans-activation of the PX40 gene product of HTLV-I for activation of IL-2-R gene might not be coincidentally associated with stimulation for cell proliferation.
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The optimal mode of transesophageal atrial pacing was determined by clinical electrophysiologic studies in 15 healthy adult volunteers. The point at which the unipolar atrial electrogram was biphasic and largest in amplitude (35.4 +/- 1.6 cm from the incisors) was considered the best stimulation site for atrial pacing. The stimulation threshold on bipolar pacing (using the proximal pole as cathode and the distal pole as anode) at this site was 27 +/- 7 mA, which was significantly lower (p less than 0.001, n = 10) than that on unipolar cathodal stimulation (41 +/- 8 mA). Although the stimulation threshold tended to be higher with a No. 10Fr electrode catheter (30 +/- 5 mA) than with a No. 6Fr catheter (27 +/- 7 mA), the difference was statistically insignificant (n = 9). When the interpolar distance in bipolar stimulation was varied in 5 steps from 12 to 80 mm, the threshold was lowest at the distance of 24 mm. Of the 10 pulse durations tested, ranging from 0.25 to 128 ms, 8 ms appeared most desirable in minimizing the total amount of current and chest discomfort accompanying the pacing. With the optimal site, interpolar distance and pulse duration, transesophageal atrial pacing was successfully performed in all patients, without producing significant complications such as chest pain. Transesophageal atrial pacing is noninvasive, technically simple and efficient, and may be valuable in the diagnosis and treatment of various cardiac arrhythmias.
With the aim of pain control in chronic pancreatitis without the morbidity of insulin-dependent diabetes, a new procedure was devised to completely resect the postganglionic pancreatic nerves and to totally free the pancreas from the posterior abdominal wall. This procedure was performed on two patients with follow-up periods of 24 and 10 months. Pain was resolved in both patients, and their blood glucose levels were substantially unchanged. This new approach offers a means of relieving pain with preservation of endocrine function in selected patients with chronic pancreatitis, especially in patients who have a small pancreatic duct.
Human epidermal growth factor (urogastrone; UG) is a 53-amino acid polypeptide hormone. A 192-bp DNA fragment containing the coding sequence for methionyl UG (Met-UG) and the ribosome-binding site (RBS) was chemically synthesized and placed downstream from the promotor for the Escherichia coli outer-membrane lipoprotein gene (lpp) on a plasmid. E. coli cells harboring the plasmid directed the synthesis of Met-UG at 10(2)-10(3) molecules per cell. Next, the coding sequence for Met-UG was inserted in a runaway-replication plasmid and expressed under the control of the lpp promoter and the RBS derived from bacteriophage Mu cII gene. Upon heat induction, the cells harboring the recombinant plasmid synthesized 10(5) molecules of Met-UG per cell.
Elevated urinary trehalase activity was observed in the inhabitants of the Jinzu River basin. Urinary trehalase activity was correlated with other urinalysis components, such as beta 2-microglobulin, glucose, amino nitrogen, and cadmium, of which a high level was observed in cadmium-polluted areas as compared with the reference area. Renal trehalase is specifically localized in tubular brush borders [M. Nakano, J. Histochem. Cytochem., 30 (1982) 1243-1248]. From these results it is inferred that tubular brush-border damage occurs in inhabitants of the Jinzu River basin.
Following the promotion of anti-air pollution measures in steam power stations using crude oil, atmospheric concentrations of sulphur dioxide, nitrogen dioxide and suspended particulates have declined. These changes in atmospheric concentrations were accompanied by a decline in the prevalence of respiratory symptoms among schoolchildren living near the power stations. In analysing the correlation between air pollutant concentrations and the prevalence of respiratory symptoms, those with positive skin reactions to house dust extract (the positive group) showed a more significant correlation coefficient compared to those who had never had a positive skin reaction (the negative group). In addition, schoolchildren more heavily exposed to air pollutants showed the higher prevalence of respiratory symptoms than the others. With regard to the kind of air pollutants, both sulphur dioxide and nitrogen dioxide were more closely associated with the prevalence of respiratory symptoms than suspended particulates. This study has therefore demonstrated that the positive group is a useful population for monitoring the health effects associated with low-degree air pollution of gaseous agents.
Of 683 cases of primary epithelial tumors arising in the parotid gland, 20 cases could be defined as adenocarcinomas, constituting 2.9% of the total number or 10.0% of 201 malignant tumors. These adenocarcinomas were characterized by a marked diversity in the histologic manifestations, presenting tubular, papillary, pseudoadenoid cystic, cribriform, trabecular, sarcomatoid, and other patterns. Basically, however, they could be classified into two major subtypes, i.e., tubular and papillary variants on the basis of their predominant histological patterns. The tumor cells showed a distinctive sign of high grade malignancy such as the occurrence of many mitotic figures and involvements of lymphatic vessels and/or blood vessels. Ultrastructurally, the tumor cells consisted of two basic varieties, resembling myoepithelial cells and duct epithelium. It is thus suggested that immature tumor cells could differentiate into a structure mimicking an intercalated duct. Clinicopathologically, the tumors were seen with a higher frequency in middle-aged males (average 44 years of age).
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