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Biomedical subjects

T Takada

Publications and source records attributed to T Takada.

At least 181 records · Page 10Linked to original sources
PubMed1993

Angioedema likely related to angiotensin converting enzyme inhibitors.

Angioedema associated with angiotensin converting enzyme inhibitors is a rare adverse reaction. It commonly involves the face, oropharyngeal and laryngeal tissues. To our knowledge, angioedema of the abdominal viscera related to angiotensin converting enzyme inhibitors has not been reported previously. We present a rare case of a patient who had episodes angioedema and abdominal pain with ascites probably related to the ACE inhibitor captopril.

Abdominal Pain↗
PubMed1993

Pylorus-preserving pancreatoduodenectomy: technique and indications.

Pylorus-preserving pancreatoduodenectomy is accepted as definitive treatment of some malignancies, such as cancer of the duodenal papilla, and cancer of the lower bile duct. However, its use in cancer of the head of the pancreas is controversial. We have applied pylorus-preserving pancreatoduodenectomy combined with extended lymph node dissection as the major technique in cases of malignant disease. Also, when invasion of the portal vein is confirmed or suspected, portal vein resection has been combined. However, when the duodenal bulb or pyloric ring has been invaded by cancer, the classic Whipple operation has been indicated. Our experience over the last 11 years has demonstrated no statistical difference in the 5-year survival rate between patients with pancreatic head cancer treated with the Whipple procedure (n = 25, 34.8%) and pylorus-preserving pancreatoduodenectomy (n = 16, 33.3%). Also, the postoperative quality of life proved to be better in patients with pylorus-preserving pancreatoduodenectomy. These data support the continued application of pylorus-preserving pancreatoduodenectomy for the treatment of cancer of the head of the pancreas.

Gastrostomy↗
PubMed1993

[Histological study in renal grafts--macrophages population in renal grafts].

We studied about the histological findings of the kidneys including of the infiltrated macrophages in one hour post-transplantation kidney biopsies (one hour biopsies) and re-biopsies on 11 patients. They were transplanted at 4-28 (ave. 15.1 +/- 3.8) years of age. The periods from transplantation to this study were 1.0-7.3 (ave. 3.3 +/- 1.9) years. 6 patients had acute rejections, and their renal function became normal after treatments. At this study, all grafts survived, and the patients had no abnormal findings except two (one had proteinuria, another had proteinuria and mild elevation of serum creatinine level). But histologically, five patients had chronic rejections among the 8 patients who had re-biopsies more than one year after transplantation. And we experienced 6 patients whose kidney had mesangial IgA deposits in one hour biopsies and 3 patients who had de novo type glomerulonephritis in re-biopsies (IgA neuropathy in 2 patients, membranous nephropathy in one). In one hour biopsies, the populations of macrophages in the interstitium were 4.18 +/- 2.84/mm2 in the patients who would have acute rejections (6 patients), 1.38 +/- 1.13/mm2 in the cases who would not have. It was suspected that the increase of the infiltrated macrophages in the interstitium in one hour biopsies could predict acute rejections. In re-biopsies, many macrophages infiltrated in the interstitium (8.34 +/- 4.86/mm2), particularly on patients who had chronic rejections.

Adolescent↗
PubMed1993

[Evaluation of colorectal hepatic metastases with combined modality therapy].

We treated synchronous hepatic metastases in colorectal cancers with combined modality therapy including hepatic resection, selective intra-arterial infusion chemotherapy, and thermocoagulation therapy using a microwave tissue coagulator and compared the value of such therapies. Synchronous hepatic metastases were noted in 563 patients with colorectal cancer who had undergone surgery in our department over the past ten years. Forty-four patients were studied. Six patients underwent hepatic resection only (group A). Another six were subjected to hepatic resection and the residual lesions were treated with selective intra-arterial infusions and thermocoagulation therapy (group B). Fourteen patients were treated with either selective or subselective intra-arterial infusions (group C). The remaining 18 patients were treated in other ways (group D). Cumulative survival, estimated by the Kaplan-Meier method, was compared. One- and three-year cumulative survival rates of patients were 100% and 74% in group A, 100% and 67% in group B, 62% and 0% in group C, and 38% and 5% in group D, respectively. H1 patients accounted for 83% in group A, 33% in group B, 7% in group C, and 22% in group D. The high rate of survival in group A was because of the greater number of H1 patients. One- and three-year survival rated among H2-H3 patients were 100% and 54% in group B, 62% and 0% in group C, and 35% and 14% in group D, respectively. Survival of H2-H3 patients was higher in group B than in group C or D.

Antineoplastic Agents↗
PubMed1993

[Liver metastases from breast cancer: survival and an attempt at cauterization and thermocoagulation therapy combined with selective intra-arterial infusion chemotherapy].

During the past thirteen years, 599 patients with primary breast cancer underwent surgery in our hospital. Nine of them died of liver metastases and the median survival time after detection of liver metastases was five months (range 1-32 months). Four are still alive with liver metastases. Based upon these results, we attempted intraoperative, ultrasound-guided cauterization and thermocoagulation for three patients to improve their prognosis and postoperatively treated them with hepatic arterial infusion chemotherapy. During surgery, a monopolar electrode was inserted with an ultrasonic guide. One round of cauterization lasted for 10 seconds at 100 W, and was repeated until the tissue around the tumor became hyperechoic. The antitumor effect of the therapy was assessed by histological examination of resected liver tissues. Tumor coagulation and necrosis were observed to be consistent with the cauterized area. On CT scanning, treated areas were shown to be of low density and homogeneous. Since this therapeutic approach acts directly on unresectable tumors and is safe, it seems to provide a useful means for intraoperative regional treatment of tumors.

Breast Neoplasms↗
PubMed1993

[Evaluation of subselective intraarterial infusion chemotherapy in far advanced gastric and colorectal cancer].

We investigated the usefulness of subselective intraarterial infusion chemotherapy in far advanced gastric and colorectal cancer. Among gastric and colorectal cancer cases undergoing surgery at our hospital for the past ten years, patients with and without palliative resection were studied. Forty gastric cancer patients and 29 colorectal cancer patients were treated by subselective intraarterial infusion chemotherapy. In gastric cancer cases without resection, a significantly longer survival was noted in patients undergoing this therapy with over 5 g of 5-FU than those treated with conventional chemotherapy. In gastric cancer patients with palliative resection and colorectal cancer patients, survival time was longer by intraarterial infusion with over 5 g of 5-FU, but not significant. Partial response was obtained in 5 cases of gastric cancer and 3 cases of colorectal cancer, and clinical symptoms were improved in 44% of the patients. The main complications of this therapy were myelosuppression and occlusion of the catheter, but none of them were serious. For the improved quality of life of cancer patients, subselective intraarterial infusion chemotherapy is considered a safe and useful form of treatment.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

Duodenum-preserving pancreatoduodenostomy. A new technique for complete excision of the head of the pancreas with preservation of biliary and alimentary integrity.

A new technique for complete excision of the head of the pancreas with preservation of the biliary and digestive tract is described. A series of 11 patients with chronic pancreatitis, pancreatic divisum, or a low-grade malignancy (mucus-producing pancreatic cancer) who underwent the procedure is reported. Previously described techniques for "duodenum-preserving pancreatic resection" differ from ours in two ways. First, other techniques accomplished only a "partial resection", retaining a rim of pancreas along the duodenum, and second, the pancreatoenteric anastomosis utilized a Roux-en-Y jejunal loop. Our procedure permits complete resection of the pancreatic head, which in turn permits a pancreatoduodenal anastomosis. This preserves the normal physiology of pancreatic digestive function. To assure an adequate blood supply to the duodenum, retroperitoneal vessels must be preserved by avoiding Kocher's maneuver, and the posterior superior pancreatoduodenal artery must also be preserved. This operation was successfully performed in 8 consecutive patients when these provisos were adhered to.

Anastomosis, Surgical↗
PubMed1992

[Study on uric acid metabolism in patients with primary aldosteronism].

This study was conducted to elucidate renal uric acid metabolism in patients with primary aldosteronism (PA;16 cases) as compared with normotensive subjects (NT;25 cases) and essential hypertensives (EHT;51 cases). All subjects were hospitalized and received a regular diet(Na;120 mEq,K;75 mEq,daily) for more than two weeks, after which renal clearance tests were performed, and serum uric acid(SUA), fractional excretions of uric acid(FEUA), sodium(FENa), and inorganic phosphorus(FEP) were evaluated. Plasma aldosterone concentration(PAC) was measured in 16 patients with PA before treatment and in 8 patients after adrenalectomy. SUA was lower in PA than in either NT or EHT, and this lowering was more obvious in male subjects. In NT, PA and EHT, FEUA, an index of renal excretion of uric acid, correlated negatively with SUA and positively with FENa and FEP, which reflected sodium reabsorption at the renal total tubules and proximal tubules, respectively. Although FENa was nearly the same in all the three groups, FEUA and FEP were significantly higher in PA than in EHT or NT. However, no significant correlation was found between PAC and SUA or FEUA in PA. In PA a significant increase of SUA, and decreases of FEUA and FEP were observed after the removal of adenoma compared to before the surgery. These results suggest that uric acid transport might be closely related to sodium transport in the renal tubules, particularly at the proximal site, and also lead to the conclusion that the lower SUA in PA resulted from the suppression of reabsorption and/or an enhancement of secretion of uric acid in the proximal tubules, being related to the so-called escape phenomenon.

Adenoma↗
PubMed1992

Quantitative immunogold localization of Na, K-ATPase along rat nephron.

Ultrastructural localization of Na, K-ATPase alpha-subunit along rat nephron segments was investigated quantitatively by immunogold electron microscopy on LR-White ultrathin sections using affinity-purified antibody against alpha-subunit of the enzyme. Ultrathin sections were incubated with the antibody at a saturation level and the number of gold particles bound per micron of the plasma membrane (particle density) of the tubular epithelial cells from the proximal tubule to the collecting duct was determined. In all the tubular epithelial cells, gold particles were located exclusively on the basolateral surface, and no significant binding of gold particles to the apical surface was observed. Distribution of gold particles on the basolateral membranes was quite heterogeneous; lateral membranes and infolded basal membranes were highly labeled, whereas the basal membranes which are in direct contact with the basal lamina were scarcely labeled. The average particle density on the basal surface was highest in the distal straight tubule cells (11.4 units), very high in the distal convoluted tubule cells (9.8 units), intermediate in the proximal tubule cells (3.3 units), in the connecting tubule cells (4.3 units), and in the principal cells of the collecting duct (5.6-3.8 units), low in the thin limb of Henle's loop (1.0 unit), and at the control level in the intercalated cells in the connecting and collecting duct. The relative number of gold particles/mm nephron segment and the relative number of gold particles in the various nephron segments were calculated using quantitative morphological data. The estimated distribution profile of the former was in good agreement with the Na, K-ATPase activity profile in rat nephron, which was determined biochemically with a microenzymatic method.

Animals↗
PubMed1992

An analysis of life history evolution in terms of the density-dependent Lefkovitch matrix model.

The evolution of demographic characteristics is considered in terms of the density-dependent Lefkovitch matrix model, which describes a species' population dynamics with a stage-specific pattern of reproduction and mortality. We obtain the invadability condition of a mutant-type into the wild-type population at the equilibrium state. The condition depends on the left and right eigenvectors at the equilibrium state. The condition depends on the left and right eigenvectors at the equilibrium state and the difference, between wild-type and mutant-type populations, of the values of elements in the Lefkovitch matrix at the equilibrium state. It is also shown that if elements of the density-dependent Lefkovitch matrix are decreasing functions of population density, then the equilibrium population density increases in the process of natural selection; that is, K-selection acts even on the stage-structured population. The evolution of life history in perennial plants is discussed through two models as an application of the above results. The evolution of perennial plants with no vegetative reproduction is analyzed in the first example. It is shown that whether monocarpic perennials (which reproduce once and die) or polycarpic perennial plants (which reproduce more than once) are favored depends on the cost of a produced seed. The second example concerns perennial plants that reproduce vegetatively. It is shown that whether monocarpic or polycarpic perennial plants are favored depends on the cost of a seed and that where vegetative reproduction is common, polycarpic perennials with no seed reproduction are favored.

Mathematics↗
PubMed1992

Slow positive dorsal cord potentials activated by heterosegmental stimuli.

Heterosegmental slow positive waves (HSPs) and segmental spinal cord potentials were recorded from the cord dorsum in ketamine-anesthetized rats. Forepaw stimulation produced HSPs in the lumbo-sacral enlargement (lumbar HSPs), whereas hind paw stimulation evoked HSPs in the cervical cord (cervical HSP). Both the HSP and the secondary component of the slow positive wave (P2s) in the segmental spinal cord potential were highly vulnerable to anesthetics and completely disappeared after spinal cord transection at the C1/2 level, indicating that both the HSP and P2s are produced by a long feedback loop via supraspinal structures. The lumbar HSP evoked by forepaw stimulation was maximal in amplitude at the L5 level and more dominant in the ipsilateral cord dorsum than in the contralateral one, but widely distributed in the lumbo-sacral cord. A variability of onset (7-18 msec for cervical and 5-17 msec for lumbar HSPs) and peak (22-35 msec for cervical and 12-50 msec for lumbar HSPs) suggests the existence of several nuclei to form the feedback loops for descending impulses to produce the HSPs. There were no peak latency differences between the HSPs and P2s. Since there were several similar characteristics between the P2s and HSP such as a high vulnerability to anesthetic, a complete disappearance after high spinal transection and similar response curves to graded intensities of stimulation, there may be a close relationship between their feedback nuclei and the pathways mediating them. All wide dynamic range (WDR) neurons (12/12) in lamina V of Rexed responded to heterosegmental stimulation with inhibition of firing.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Deoxyspergualin, a novel immunosuppressant, markedly inhibits human mixed lymphocyte reaction and cytotoxic T-lymphocyte activity in vitro.

Deoxyspergualin (DSG) has demonstrated potent immunosuppressive activities in vivo. However, because of its lability in culture medium, the mechanism of activity has not yet been identified in vitro. In this study, a more stable analogue, deoxymethylspergualin (MeDSG), was used to investigate the in vitro immunosuppressive activity of DSG. MeDSG suppressed both human mixed lymphocyte reaction (MLR) and cytotoxic T-lymphocyte (CTL) activity at doses greater than 0.1 micrograms/ml in vitro. In kinetics studies, MeDSG was found to suppress a MLR when added on day 3 of a 7 day MLR incubation but cyclosporin A (CYA) suppressed a MLR only when added during the initial stage of a MLR (i.e. on day 1). In studies of cell surface phenotype in the MLR, MeDSG treatment decreased the numbers of CD8+ lymphocytes but those of CD4+ lymphocytes were not affected. In addition, MeDSG had no significant effect on interleukin-2 (IL-2) receptor expression or IL-2 production. These results suggest that MeDSG suppresses the T-cells which are proliferating competent cells such as cytotoxic T-cells (CD8+), but has a different mode of immunosuppressive action compared with CYA.

Cyclosporine↗
PubMed1992

Development of a 2,048 x 2,048-pixel image intensifier-TV digital radiography system. Basic imaging properties and clinical application.

RATIONALE AND OBJECTIVES: A 2,048 x 2,048-pixel matrix image intensifier (II)-TV digital radiography system has been developed. Potential clinical applications of this new II-TV system were investigated. METHODS: Basic imaging properties were assessed with clinical applications to gastrointestinal (GI) tract and chest examinations. RESULTS: Basic imaging properties showed improvement of modulation transfer functions (MTFs) from the 1,024 x 1,024- to the 2,048 x 2,048-pixel matrix and approximated the screen-film system at low spatial frequencies. Receiver operating characteristic (ROC) curves of simulated linear shadows improved similarly. Clinical applications showed that the image quality of the 2,048 x 2,048-pixel matrix was comparable with that of the screen-film system for upper GI and chest radiography, but the image quality of the screen-film system was better for the lower GI tract. CONCLUSIONS: The authors' II-TV digital radiography system is clinically applicable to gastrointestinal and chest examinations.

Digestive System↗
PubMed1992

Somatic mutation during metastasis of a mouse fibrosarcoma line detected by DNA fingerprint analysis.

Metastatic nodules were examined by DNA fingerprint analysis. The probes used, Pc-1 and Pc-2, detect mutations as shifts in bands of the minisatellite loci which are dispersed among chromosomes. Four clonal lines of a fibrosarcoma from an F1 mouse (C57BL/Ka x C3H/He) were selected for various metastatic potentials upon inoculation into syngeneic mice. These four lines exhibited many extra bands resulting from recombination and/or DNA slippage, indicating accumulation of mutations during the successive passages in mice. One of the four, a 505 cell line which had been passaged extensively in vitro and consisted of a heterogenous population, was inoculated into thirteen syngeneic mice, and gave rise to six lung metastatic nodules in two mice. All the nodules showed band-patterns distinct from one another, although nodules within a given mouse tended to show similar patterns. When a genetically tagged 505-05-01 clone was analyzed, three of nine metastatic nodules obtained also revealed new bands. These results strongly suggest that somatic mutations occur at a high frequency during metastasis, providing direct evidence of genetic instability of the tumor cells.

Animals↗
PubMed1992

Telomere elongation frequently observed during tumor metastasis.

Changes in the number of telomere repeat arrays have been examined during metastasis of two mouse tumor cell lines. Telomeres were detected as bands and a smear by pulsed-field gel electrophoresis and gel-hybridization using (TTAGGG)4 as a probe. Very long size variants of telomeres were frequently observed in metastatic nodules. This suggests that at least some of the tumor cells have an ability to elongate telomeres. This elongation may compensate for the continuous loss of telomere repeats due to cell divisions, which would eventually lead to cell death.

Animals↗
PubMed1992

Two children with bromate intoxication due to ingestion of the second preparation for permanent hair waving.

We report two children who suffered from sodium bromate intoxication due to ingestion of the second preparation for permanent hair waving (the second permanent preparation). One child suffered from gastrointestinal symptoms only. The other exhibited slight acute renal insufficiency. Results of the histological examination of the kidney in the sick child with acute renal insufficiency showed sporadic epithelial separation of the proximal tubuli under light microscopy. In addition, we could demonstrate more clearly epithelial separation and unbroken tubular basement membranes under electron microscopy (EM). To our knowledge, this is the first report of EM findings in this disease. The mechanism of epithelial injuries by bromate is not clear.

Acute Kidney Injury↗