Biomedical subjects
Publications and source records attributed to K Takagi.
Ovalbumin (OA) aerosol exposure caused an increase in phospholipase (PLase) activity in guinea pig lung membranes and in leukotriene B4 (LTB4) in lung lavages with subsequent neutrophil influx into lung lavages. These results suggest that activation of PLase after exposure to OA aerosol triggers an increase in LTB4 synthesis resulting in neutrophil influx into the airways.
Explore the source record for details and available documents.
The findings reviewed above demonstrate that cAMP can act at several distinct loci to enhance steroidogenesis. Analogs of cAMP stimulate the accumulation of the mRNAs which encode components of the steroidogenic machinery, such as the receptor for LDL and the system for the cleavage of the cholesterol sidechain. This apparently coordinated accumulation of specific mRNAs results from increased transcription of the relevant genes. Transacting factors modulated by cyclic AMP may influence common enhancer sequences (e.g., TGACGTCA), and such interactions would account for the simultaneous increase in expression of specific genes on several different chromosomes. These actions of cyclic AMP enable ovarian cells to support long-term increases in steroid synthesis by increasing the quantities of proteins involved in steroidogenesis. Such changes would obviously be important during luteinization, when the potential of granulosa cells to secrete progesterone is greatly increased. Although we speak of these effects as "long-term", it is evident that they occur within a relatively short time (hours) after exposure of cells to the tropic agent. Cyclic AMP also acts to stimulate steroidogenesis post-transcriptionally. It may influence events at the translational level via interactions in the formation of "labile" proteins. In addition, the regulation of cholesteryl ester hydrolase, as well as of other enzymes involved the metabolism of cholesterol, seems to involve post-translational modifications (e.g., phosphorylation). The effects of cAMP on the cytoskeleton may be another manifestation of a post-translational response. These actions of cAMP promote acute increases in steroidogenesis (i.e., within minutes). They encompass the transport of cholesterol to the mitochondria and the regulation of access of sterol to the inner mitochondrial membranes. Future research should be directed at elucidating the exact mechanisms which permit cAMP to exert coordinate effects on the genome (Figure 8), as well as its post-transcriptional effects on various proteins and enzymes which play a role in the synthesis of steroid hormones.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Alveolar soft part sarcoma is a rare soft tissue tumor arising in extremities. The universal tendency for late widespread metastasis to lung, bone and brain, make the treatment of this tumor a particular challenge. This time, we performed the intra-arterial infusion of MMC and bronchial arterial embolization by spongel for hemoptysis of this metastatic lung tumor. Rosenbaum has reported the characteristics of angiogram of the metastatic brain tumor. In our case, bronchial arteriography showed the manifest hypervascular pattern "rosary form," "pooling" and "B-P shunt." These findings should yield benefits for the diagnosis and treatment of this metastatic lung tumor.
Explore the source record for details and available documents.
A study of the pharmacokinetic and metabolic interactions between theophylline and enoxacin was carried out under steady-state conditions in seven healthy male volunteers. Sustained-release theophylline formulation (200 mg twice daily) was given as monotherapy and coadministration of enoxacin. The total and free concentrations of theophylline in the plasma and the excreted concentration of theophylline and its metabolites in the urine were measured by a high-performance liquid chromatographic method. The mean steady-state plasma theophylline concentration significantly increased by approximately 3-fold after coadministration of enoxacin. Significant decrease in the total body clearance of theophylline was found (63%) but plasma protein binding of theophylline remained unchanged. There were a significant increase in urinary theophylline and a decrease in urinary 3-methylxanthine after coadministration of enoxacin. A decrease in the total body clearance during coadministration of enoxacin is likely to have resulted from inhibition of the 1-demethylation metabolic pathway. Further studies were needed to determine the relationship between the side effects induced by enoxacin and the theophylline dosage or its plasma concentration since side effects were experienced in all the subjects concomitantly administered enoxacin.
Follow up studies of 96 patients who underwent distal splenorenal shunt (DSRS) were performed and the loss of selectivity of DSRS was evaluated. We have established the indications for DSRS since 1980 and modified the procedures for DSRS--complete or incomplete splenopancreatic disconnection of the splenic vein (SPD)--since 1981. Twenty two of 47 patients operated before 1980 and 9 of 49 patients operated after 1980 were died of liver failure, being statistically significant (p less than 0.05). There were no significant differences in the incidence of development of encephalopathy before and after 1980 (7 patients before 1980 and 6 patients after 1980). Twenty eight of 69 patients without SPD and one of 16 patients with incomplete SPD were died of liver failure, being statistically significant (p less than 0.025). Twelve of 69 patients without SPD developed encephalopathy, while none of 27 patients with complete or incomplete SPD developed encephalopathy (p less than 0.05). It was suggested, therefore, that our established indications and DSRS with complete or incomplete SPD might be suitable for the selective shunt operation for esophageal varices.
Explore the source record for details and available documents.
The use of Bayesian algorithm on theophylline pharmacokinetics was studied in asthmatic patients. Each patient received multiple oral doses of the sustained-release theophylline tablet formulation, Theo-Dur, in an amount of 200-400 mg as maintenance dose. Plasma theophylline concentration was measured by a commercially available substrate-labeled fluorescent immunoassay. The data were analyzed by applying a one-compartment model with both zero-order and first-order absorptions based on a nonlinear least squares method, Bayesian algorithm. The present study indicated that the zero-order absorption model provided better estimated pharmacokinetic parameters than the first-order absorption model. It was also found that prediction by the Bayesian method is dependent on number of sampling trials, but the best sampling time is still unknown. This may be due to the small peak-trough plasma concentration differences. From these findings, we suggest that parameters with larger variances should be chosen by considering the interindividual and intraindividual variabilities in order to improve the accuracy of population pharmacokinetics.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
In the endoscopic treatment of early gastric cancer, it is absolutely necessary to adapt a radical approach. The indication for this technique in 545 surgically resected cases of single gastric cancer was studied and technical evaluation was made of endoscopic resection (ER) in 98 of early gastric cancer lesions. Except for 2 special lesions of early gastric cancer, invasion depth m and sm minute invasion [sm(+)] cancer did not show lymph node metastasis [n(+)], but this was recognized in sm(++) cancer showing more than moderate invasion and which was deeper than pm cancers. The applicable lesions were selected excluding the n(+)-risk group with invasion deeper than sm(++) based on histological type, macroscopic type, size and the presence or absence of ulcers(Ul). These were differentiated type II a less than 2 cm in size, differentiated type Ul(-) II c of less than 1 cm and undifferentiated type Ul(-) II c of less than 5 mm in areas excluding the fundic gland mucosa. Our method of ER is endoscopic double snare polypectomy. II a or II c lesion is artificially squeezed into a pedunculated form. The cutting snare is placed over the peduncle, the grasping forceps are replaced with another snare to grasp the tumor firmly. Then cutting snare is applied to include sufficient normal mucosa surrounding the lesion and coagulating current is passed through to slowly resect the ared. The 1st-ER healing ratio, remnant ratio and recurrence ratio of standard ER in 55 II a and 30 II c lesions were 83.5, 12.9 and 3.5% respectively. The recurrent cases were retrospectively found originals in the remnant. Among remnant and recurrences, the 2nd-ER healing ratio was 43% (6/14) and surgically treated cases were 8 (6 inapplicable cases), the final ER healing ratio being 90.6% and satisfactory. Most of the remnant lesions were II a of more than 2 cm, and II c of more than 1 cm for differentiated type and II c for undifferentiated type. As ER could not be applied to these lesions, its indication was confirmed to be technically satisfactory.
Explore the source record for details and available documents.
Gastric lymphatics in 200 patients of gastric cancer were studied by injection of activated carbon particles (CH44). By observing the carbon flow intraoperatively and examining stained lymph nodes, gastric lymphatics for individual regions (cardia, lesser curvature, left greater curvature and right greater curvature) were evaluated. The cardiac orifice has a main series of lymphatics along the left gastric artery and also has other lymphatics along the splenic artery, left phrenic artery, esophagus, lesser omentum and diaphragm. The left greater curvature depends on the lymph flow along the splenic artery. The lesser curvature has a main lymphatic stream along the left gastric artery. The right greater curvature has convened lymphatics around pancreatic head. Most streams gather around celiac axis, while the flow along right gastro-epiploic vein is also important. We also studied the relationship between the site of gastric cancer and metastasis is to the lymph nodes in 1097 gastrectomized patients. They had received more than R2 lymphatic dissection successfully. In the cases with lesions located in the upper part of the stomach, n4 (positive findings of metastasis to group 4 lymph nodes) is greater than n3 (positive findings of metastasis to group 3 lymph nodes). We concluded that most of gastric lymphatics run along the proper gastric vessels and gathered around celiac axis. For lymph node dissection in gastric cancer, it is important to know the direction of the gastric lymphatics based on tumor sites.