Biomedical subjects

C Konno

Publications and source records attributed to C Konno.

At least 19 recordsLinked to original sources

PubMed2001

Thermo-responsive culture dishes allow the intact harvest of multilayered keratinocyte sheets without dispase by reducing temperature.

To develop new technology for harvesting transplantable cultured epithelium without dispase treatment, human keratinocytes were plated on culture dishes grafted with a thermo-responsive polymer, poly(N-isopropylacrylamide). The grafted dish surfaces are slightly hydrophobic above 32 degrees C, but reversibly change to hydrophilic below this temperature. According to the method of Rheinwald and Green, keratinocytes proliferated and made a multilayer on the grafted surfaces at 37 degrees C, as on the nongrafted culture dishes. The multilayered keratinocyte sheets were detached from the grafted surfaces only by reducing temperature to 20 degrees C without need for dispase. No cell remnants were observed on the dishes. Such cell sheet detachment was not observed on nongrafted dishes. Immunoblotting of harvested keratinocyte sheets revealed that dispase treatment disrupted E-cadherin and laminin 5, while these molecules remained intact in the keratinocyte sheets harvested by only reducing temperature from the grafted dishes. Transmission electron microscopy revealed that desmosomes were destroyed in dispase treatment but retained in low-temperature treatment. Use of thermo-responsive dishes was examined as a new tool for tissue engineering to achieve the preparation of artificial epithelium for cell transplantation as well as for the investigation of intact multilayered keratinocyte sheets.

Cell Culture Techniques↗

PubMed2000

Temperature-responsive culture dishes allow nonenzymatic harvest of differentiated Madin-Darby canine kidney (MDCK) cell sheets.

We have developed a temperature-responsive culture dish grafted with a poly(N-isopropylacrylamide) (PIPAAm). Various types of cells adhere, spread, and proliferate on the grafted dishes in the presence of serum at 37 degrees C. By reducing only temperature, these cells can be harvested noninvasively from the dishes according to rapid hydration of the grafted polymer. Because the harvest does not need enzymatic digestion, differentiated cell phenotypes are retained. In the present study, a renal epithelial cell line, Madin-Darby canine kidney (MDCK) cell, was cultured on the dishes, and cell behavior was examined. MDCK cells showed differentiated phenotypes such as dome formation during long-term culture, similar to on ungrafted dishes. After 1-week culture at 37 degrees C, trypsin digestion disrupted cell-cell junctions but failed to liberate cells from both ungrafted and grafted dishes. However, short-term incubation at 20 degrees C released confluent MDCK cells as a single contiguous cell sheet only from the polymer-grafted dishes because of selective disruption of the cell-surface binding. Immunocytochemistry with anti-beta-catenin antibody revealed that functional cell-cell junctions were organized even in the recovered cell sheets. Intriguingly, incubation time at 20 degrees C required for cell sheet detachment gradually shortened during long-term culture before reducing temperature. The acceleration of cell detachment was correlated to the decrease of a single cell area by means of cell contractile force. These findings suggest that cell sheet detachment from PIPAAm-grafted dishes should be accomplished by both PIPAAm hydration and cellular metabolic activity such as cell contraction.

Acrylic Resins↗

PubMed2000

Release of adsorbed fibronectin from temperature-responsive culture surfaces requires cellular activity.

We have previously developed a temperature-responsive cell culture surface by grafting poly(N-isopropylacrylamide) that changes its surface hydrophobicity in response to temperature. While this surface shows similar hydrophobicity to that of commercial polystyrene cell culture surfaces and facilitates cell adhesion and proliferation at 37 degrees C, grafted polymer becomes hydrophilic below 32 degrees C and releases spread cultured cells without trypsin. Temperature-regulated cell detachment requires cell metabolic activity requiring ATP consumption, signal transduction, and cytoskeleton reorganziation. Precoating these surfaces with fibronectin (FN) improves spreading of less adhesive cultured hepatocytes and reducing culture temperature releases cultured cells from FN-adsorbed grafted surfaces. Immunostaining with anti-FN antibody revealed that only FN located beneath cultured cells is removed from culture surfaces after reducing temperature. FN adsorbed to surface areas lacking direct cell attachment remained surface-bound after reducing temperature. A novel concept of active cell detachment is also discussed.

Acrylic Resins↗

PubMed2000

Role of prostaglandin E2 and leukotriene B4 in skin reaction induced by transdermal application of propranolol.

Dermal application of propranolol (PRL) induced formation of erythema and edema, and pseudoeosinophil infiltration in epidermis and dermis at the application site in guinea pigs. We investigated the production of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) at the application site of PRL and the role of these inflammatory chemical mediators in the occurrence of the skin reactions. PGE2 was found to be produced at the application site slightly after the accumulation of PRL released from the adhesive bandage in the patch test, and the amount of PGE2 increased continuously, with a peak value obtained at 24 h after application. The time-course changes resembled those of delta a* value, the index of erythema formation determined by colorimetric measurement, and edema formation. The production of PGE2 by dermal application of PRL was suppressed by local pretreatment with dexamethasone or indomethacin. However, no notable production of LTB4 was observed at the application site of PRL.

Administration, Cutaneous↗

PubMed1999

Decrease in culture temperature releases monolayer endothelial cell sheets together with deposited fibronectin matrix from temperature-responsive culture surfaces.

Bovine aortic endothelial cells were cultured on surfaces grafted with a temperature-responsive polymer, poly(N-isopropylacrylamide) (PIPAAm), in the presence of serum. Cells adhered, spread, proliferated, and reached confluency as observed on ungrafted tissue culture polystyrene dishes. A decrease in culture temperature released cells only from the grafted surfaces without enzymatic or ethylenediaminetetraacetic acid treatment. Upon lowering temperature, the culture surfaces changed from hydrophobic to hydrophilic owing to the hydration of grafted PIPAAm and thus weakened the cell attachment to the dishes. Released cells maintained cell-cell junctions composing monolayer cell sheets. Immunoblotting and immunofluorescence microscopy revealed that fibronectin (FN) was deposited and accumulated on the grafted surfaces during the culture. Furthermore, the deposited FN matrix adhering to cell sheets was also recovered from temperature-responsive surfaces by low-temperature treatment, while trypsin treatment destroyed the matrix. The recovery of FN by low-temperature treatment was as high as by physical scraping with a rubber blade. Temperature-responsive surfaces can provide a novel method to use cultured confluent cell sheets for tissue engineering, and also to elucidate structure and function of deposited extracellular matrix during cell culture.

Acrylamides↗

PubMed1999

Skin toxicity of propranolol in guinea pigs.

The skin toxicities of propranolol were studied in guinea pigs. In the primary and cumulative skin irritation studies, the skin reactions and the histopathological changes were observed in all animals treated with propranolol, and those tended to increase with the increase of propranolol dosage. The skin reactions increased with the application times of propranolol up to 7 days in the cumulative skin irritation study. In the skin sensitization, the phototoxicity and the skin photosensitization studies, no skin reactions were observed in any animals used in the studies. These results indicate that propranolol caused skin irritation, but was negative for skin sensitization, phototoxicity and skin photosensitization in guinea pigs.

Adrenergic beta-Antagonists↗

PubMed1998

Relationship between the skin permeation movement of propranolol and skin inflammatory reactions.

We studied inflammatory reactions induced by dermal application of the beta-blocker propranolol (PRL) in ethanol to guinea pigs in order to elucidate the relation of the reactions with the cumulative PRL permeating amount through the stratum corneum or the PRL content in the stripped skin, and to investigate the chemical mediators responsible for the reactions. The cumulative PRL permeating amount through the stratum corneum increased rapidly up to 2 h after dermal application, then increased linearly with time up to 24 h after application. Visual observation revealed formation of erythema and edema at the applied site of PRL, and histopathological examination revealed infiltration of pseudoeosinophiles of dermis and epidermis and degeneration/necrosis of epidermis. In general, it was considered that the duration and the extent of these reactions were dependent on the PRL dosage and application time. It was expected that the cumulative PRL permeating amount through the stratum corneum could be used to predict possible inflammatory reactions during development of transdermal drug delivery systems. On the other hand, contact of PRL with guinea pig skin tissues released histamine, and intradermal injection of PRL caused an increase of capillary permeability at the site of application. Also, the inhibitory effects of anti-inflammatory agents (diphenhydramine, dexamethasone, indomethacin, cyproheptadine hydrochloride, CV3988 and AA-861) to PRL-induced erythema formation demonstrated that histamine and prostaglandins were responsible for the inflammatory reactions induced by PRL.

Adrenergic beta-Antagonists↗

PubMed1997

Relationship between amount of beta-blockers permeating through the stratum corneum and skin irritation after application of beta-blocker adhesive patches to guinea pig skin.

We evaluated the relationship between the cumulative amounts of 5 kinds of beta-blockers (alprenolol, oxprenolol, timolol, acebutolol and atenolol) permeating through the stratum corneum and a* values obtained by measuring the formation of erythema, a skin irritation reaction, with a chromameter after transdermal application of adhesive patches containing 2 beta-blocker to the skin of guinea pigs. The cumulative amount of beta-blocker released from each adhesive patch to the skin increased with the increase in application time. The contents of alprenolol, oxprenolol and timolol in the stratum corneum and in the stripped skin increased markedly up to 4 h after application and thereafter were maintained at high levels up to 24 h. The contents of acebutolol and atenolol, on the other hand, increased up to 24 h, but these values were low. a* values of all adhesive patches 24 h after application were higher than those before application. The correlation coefficients between the cumulative amounts of alprenolol, oxprenolol, timolol, acebutolol or atenolol permeating through the stratum corneum and (delta a* -delta a*Placebo) values were 0.739, 0.717, 0.722, 0.551 and 0.633, respectively. The correlation coefficient calculated by averaging the cumulative amounts of 6 kinds of beta-blockers permeating through the stratum corneum [including propranolol which was reported previously (Kobayashi I., et al., Biol. Pharm. Bull., 19, 839-844 (1996))] was 0.731, higher than the correlation coefficient between contents of these beta-blockers in the stripped skin and (delta a* -delta a*Placebo) values (r = 0.552). This suggests that there was a high correlation between the cumulative amounts of beta-blockers permeating through the stratum corneum and (delta a* -delta a*Placebo) values.

Acebutolol↗

PubMed1996

Relationship between the amount of propranolol permeating through the stratum corneum of guinea pig skin after application of propranolol adhesive patches and skin irritation.

In the present study we evaluated the relationship between the cumulative amount of propranolol permeating through the stratum corneum and the formation of erythema, a skin irritation reaction, after transdermal application of adhesive patches containing propranolol to the skin of guinea pigs. The intensity of erythema was expressed in terms of a* values measured with a chromameter. The a* values increased in guinea pigs after application of the adhesive patches containing 0.4 mg/cm2 of propranolol to the skin. Since the adhesive patches showed good adhesion to the skin (propranolol content is less than the saturated concentration in the adhesive base) and the cumulative amount of propranolol permeating through the stratum corneum is small, the development of erythema was considered to be mainly due to physical factors such as peeling. Even in adhesive patches containing 0.8 mg/cm2 or 1.2 mg/cm2 of propranolol, a* values increased, although adhesion to the skin is low because of crystallization of propranolol in the adhesive base. On the other hand, in these two adhesive patches, the cumulative amount of propranolol permeating through the stratum corneum increased up to 24 h after application. These findings suggest that the skin irritation reaction is due to propranolol mainly absorbed transdermally, because there is a high correlation between the cumulative amount of propranolol permeating through the stratum corneum and the a* values (r = 0.928).

Administration, Cutaneous↗

PubMed1993

Metabolic changes in cimetidine treatment for scald injury on the peritoneo-serosal surface in far-advanced gastric cancer patients treated by intraperitoneal hyperthermic perfusion.

Since pretreatment with cimetidine results in the prevention of scald injury on the peritoneo-serosal surface caused by intraperitoneal hyperthermic perfusion (IPHP) for advanced gastric cancer, the diverse influence of IPHP on patients who were either given or not given cimetidine was studied both during and after IPHP treatment. Cimetidine 50 mg/kg was injected intravenously into 12 patients immediately prior to IPHP. There were no statistical background differences between the cimetidine and control groups (those not given cimetidine). The inflow and outflow temperatures of the hyperthermic perfusate in the control and cimetidine groups were 46.1 +/- 0.1 degree C and 44.1 +/- 0.1 degree C and 46.3 +/- 0.1 degree C and 44.2 +/- 0.04 degree C, respectively. Either the pre-IPHP hypothermia or IPHP in the control group resulted in a considerable increase in serum noradrenaline and adrenaline. The intravenous administration of cimetidine led to a stransient but moderate drop in the mean blood pressure as well as a delayed appearance of high concentrations of noradrenaline and adrenaline, induced by high concentrations of circulating histamine released with cimetidine. These results suggest that the sympathetic nervous responses were activated either by hypothermia or hyperthermia. The transient hypotension and delayed increases of both serum catecholamines were attributed to a marked increase in circulating histamine, released with the intravenous cimetidine.

Blood Pressure↗

PubMed1992

Effects on tumour microcirculation in mice of misonidazole and tumour necrosis factor plus hyperthermia.

We examined the effects of misonidazole (MISO) and recombinant human tumour necrosis factor (rh-TNF) on tumour blood flow in mice given hyperthermic treatments. MISO (500 mg kg-1) or rh-TNF (6 x 10(4) unit kg-1) was administered intraperitoneally (i.p.) prior to hyperthermia to nude mice bearing a xenoplanted human gastric cancer and tumour blood flow was measured by a hydrogen diffusion method based on polarographic determinations. MISO plus hyperthermia produced a temperature-dependent decrease in blood flow and, at 43.5 degrees C, the flow decreased to 15-30% of control and remained low for up to 24 h. Blood flow following rh-TNF plus hyperthermia was less than that at the same temperatures following MISO plus hyperthermia, and, at 43.5 degrees C, the flow decreased to 10-20% of control and remained low for up to 48 h. Tumour growth delay was closely related to the duration of the decrease in blood flow. Thus, the profound decrease in tumour blood flow following hyperthermia plus MISO or rh-TNF and the consequential tumour regression may well be of potential clinical significance.

Adenocarcinoma↗

PubMed1992

[The experimental and clinical study of hyperthermia with thermosensitizer for gastric cancer patients with peritoneal seeding].

We examined experimentally and clinically the effect of misonidazole (MISO), a hypoxic cell radiosensitizer, in combination with hyperthermia. First, tissue blood flow and tumor growth of xenoplanted human gastric cancer in nude mice were measured after treatment with MISO 500 mg/kg ip plus hyperthermia at 40.5, 42.0 and 43.5 degrees C. Also clinically, 17 advanced gastric cancer patients with peritoneal seeding underwent intraperitoneal hyperthermic perfusion (IPHP). They were given MISO 1.45 g/m2 po twice (12 hours and 5 hours before IPHP). And plasma MISO levels were measured. MISO plus hyperthermia produced a more prolonged decrease of the tumor blood flow than hyperthermia alone. At 43.5 degrees C, TbF recovered 2 days after the treatment. MISO plus hyperthermia also made tumor growth delay more marked than hyperthermia alone. In gastric cancer patients treated with MISO plus IPHP, T 1/2 of serum MISO was 7.7 hours and the AUC was 1,087 micrograms.hr/ml. There were no side effects observed which were caused by MISO. Thus MISO can be an effective thermosensitizer when used in combination with hyperthermia.

Animals↗

PubMed1991

Stapled or manual suturing in esophagojejunostomy after total gastrectomy: a comparison of outcome in 379 patients.

From January 1983 to December 1989, we performed esophagojejunostomy on 379 patients who underwent total gastrectomy for gastric cancer. A mechanical EEA stapler or conventional manual suturing was used. The clinical outcomes of 199 patients in whom stapling was used (stapler group) and 180 patients in whom manual suturing was done (manual group) were compared. Two of the 199 patients in the stapler group and 3 of the 180 patients in the manual group died of causes directly related to the anastomosis. In the stapler group, 16 stapled anastomoses were formed supradiaphragmatically, and manual suturing was done for 6 patients. The highly placed anastomosis was formed without left thoracotomy or with median sternotomy in 8 of the 16 patients in whom the stapling device was used and in 1 of the 6 patients in whom manual suturing was used. The incidence of anastomotic leakage and stenosis did not differ between the groups. Thus, the mechanical stapler facilitated the construction of a rapid, reliable esophagojejunostomic anastomosis.

Aged↗

PubMed1991

[Effects of tissue cultured ginseng on the function of the stomach and small intestine].

Effects of tissue cultured ginseng on the function of the stomach and small intestine were compared with those of cultivated ginseng. Fifty percent ethanol extracts of the tissue cultured and cultivated ginseng stimulated gastrointestinal propulsion in mice. The tissue cultured ginseng also inhibited ulcer formation induced by water immersion and restraint stress, and ligature of the pylorus. In contrast, the cultivated ginseng showed no such inhibitory action.

Animals↗

PubMed1991

[Effects of tissue cultured ginseng on gastric secretion and pepsin activity].

Effects of the tissue cultured and cultivated ginseng on gastric secretion and pepsin activity were investigated. Fifty percent ethanol extracts of both cultured and cultivated ginsengs reduced gastric secretion and acid output in pylorus-ligated rats. They did not affect pepsin activity. The tissue cultured ginseng inhibited histamine and pentagastrin-induced acid secretion in rats, whereas the cultivated ginseng showed no such effect. They also suppressed acid secretion induced by 2-deoxy-D-glucose and baclofen [beta-(p-chlorophenyl)-gamma-aminobutyric acid], which are known to stimulate gastric acid secretion via the central nervous system. However, they had no effect on acid secretion induced by vagal stimulation. These results suggest that both tissue cultured and cultivated ginsengs may have an inhibitory effect on gastric secretion. The effect seems to be due to the inhibition of acid secretion via the central nervous system.

Animals↗

PubMed1991

[Prevention of scald injury due to intraperitoneal hyperthermic perfusion for far-advanced gastric cancer].

In an attempt to prevent scald injury on the peritoneo-serosal surface due to intraperitoneal hyperthermic perfusion (IPHP) for far-advanced gastric cancer patients, a histamine H2-receptor antagonist, cimetidine, was prescribed for 9 patients. The IPHP treatment was carried out with a closed circuit using a heated perfusate, and intra-abdominal temperature was kept over 44 degrees C throughout IPHP, for 120 minutes. Of 18 patients given IPHP, 9 were administered intravenously cimetidine at a dose of 50 mg/kg just before IPHP (cimetidine group) and the remaining 9 were prescribed IPHP and not given cimetidine (control group). Amounts of exudate and protein from peritoneal cavity and serum histamine were compared between the two groups. The amount of intra-abdominal exudate was 768 +/- 95 ml for 24 hours in the control group, against 408 +/- 75 ml in the cimetidine group. The protein amounts in exudate throughout IPHP were 62.5 +/- 23.5 g in the control group, against 15.9 +/- 5.4 g in teh cimetidine group. Both the exudate and protein amounts were significantly decreased in the cimetidine group, compared with the controls (p = 1.416 x 10(-7), p = 5.358 x 10(-5)). Serum histamine levels in the cimetidine group increased 2.5 to 6.5 fold for over 12 hours after IPHP, compared to those in the control group. These findings suggest that cimetidine suppresses scald injury on the peritoneo-serosal surface by competitive inhibition with histamine. Consequently, histamine originated from the scald region was released into the circulating blood. Thus, cimetidine helped to prevent thermal injury due to the IPHP.

Body Temperature↗

PubMed1991

[Clinical evaluation of intra-peritoneal hyperthermic perfusion under hypothermic general anesthesia for advanced gastric cancer].

Right after surgery, intra-peritoneal hyperthermic perfusion (IPHP) was performed under hypothermic general anesthesia for 41 gastric cancer patients with peritoneal dissemination or serosal invasion. The control group consisted of 40 patients given surgery alone. With respect to the direct antitumor efficacy of IPHP, there were no cancer cells in the peritoneal lavage from Douglas' pouch and, ascitic effusion disappeared in all patients with peritoneal dissemination. The 1- and 3-year survival rates for the IPHP group were 68% and 39%, whereas those of the control group were 30% and 0%, respectively. The survival rates for the IPHP group were better than those for the control group, with a statistically significant difference of p = 8.1 x 10(-7). As to prevention of recurrence, the incidence of peritoneal dissemination for the IPHP group was lower at p = 0.002 than the control group.

Anesthesia, General↗

PubMed1990

Positive results of combined therapy of surgery and intraperitoneal hyperthermic perfusion for far-advanced gastric cancer.

To evaluate the clinical efficacy of intraperitoneal hyperthermic perfusion (IPHP) for far-advanced gastric cancer, particularly with peritoneal seeding, we investigated the survival times of 59 patients who underwent distal subtotal gastrectomy, total gastrectomy, or total gastrectomy combined with concomitant resection of some of the remaining intra-abdominal organs. In all the 30 patients given IPHP, no cancer cells were present posthyperthermically in the lavage from the Douglas pouch. The 30 patients given IPHP lived longer than the 29 patients not given IPHP (p = 0.001), with a 1-year survival rate of 80.4% in the former group compared to 34.2% in the latter. With respect to a comparison of survival time of patients with peritoneal seeding, 7 patients not given IPHP had a 6-month survival rate of 57.1% and did not survive more than 9 months, whereas 20 patients given IPHP had 1- and 2-year survival rates of 78.7% and 45.0%, respectively; here the difference was significant (p = 0.001). The IPHP and control groups without peritoneal metastasis included 10 and 22 patients, respectively, and the 1-year survival rates are 85.4% and 45.3%, respectively. The survival rates of the former exceeded those of the latter, with p = 0.015 by the generalized Wilcoxon test. Thus this combined therapy offers the promise of extended survival for patients with far-advanced gastric cancer.

Combined Modality Therapy↗