[Progress of lung organoids in lung epithelial repair and regenerative medicine]

The mechanical barrier of lung is made up of epithelial cells which participate in gas exchange. Some of these cells have stem cell potential and are known as lung epithelial stem cells. They play an important role in maintaining lung homeostasis and repairing injured epithelial cells. Organoids are derived from pluripotent stem cells or adult stem cells cultured in a three-dimensional manner in vitro. Their structure and function are very similar to original tissues or organs. They can also self-renew, proliferate, and differentiate. Lung organoids can simulate the structure and function of epithelial cells in vitro. They provide an ideal model for the study of lung epithelial stem cells, which repair epithelial cells in vitro. Meanwhile, they provide an ideal graft for regenerative medicine. Around the lung organoids, this review concludes the mechanisms involved in lung epithelial stem cells repairing epithelial cells, summarizes their applications in regenerative medicine, and provides related reference for the therapy of lung diseases.

[Effects and mechanism of annexin A1-overexpressing human adipose-derived mesenchymal stem cells in the treatment of mice with acute respiratory distress syndrome]

Objective: To explore the effects and mechanism of annexin A1 (ANXA1)-overexpressing human adipose-derived mesenchymal stem cells (AMSCs) in the treatment of mice with acute respiratory distress syndrome (ARDS). Methods: The experimental study method was adopted. After the adult AMSCs were identified by flow cytometry, the 3rd passage cells were selected for the follow-up experiments. According to the random number table (the same grouping method below), the cells were divided into ANXA1-overexpressing group transfected with plasmid containing RNA sequences of ANXA1 gene and no-load control group transfected with the corresponding no-load plasmid. The other cells were divided into ANXA1-knockdown group transfected with plasmid containing small interfering RNA sequences of ANXA1 gene and no-load control group transfected with the corresponding no-load plasmid. At post transfection hour (PTH) 72, the fluorescence expression was observed under a fluorescence microscope imaging system, and the protein and mRNA expressions of ANXA1 were detected by Western blotting and real-time fluorescence quantitative reverse transcription polymerase chain reaction respectively (with the sample numbers being 3). Fifty male C57BL/6J mice aged 6-8 weeks were divided into sham injury group, ARDS alone group, normal cell group, ANXA1-overexpressing group, and ANXA1-knockdown group, with 10 mice in each group. Mice in the last 4 groups were treated with endotoxin/lipopolysaccharide to make ARDS lung injury model, and mice in sham injury group were simulated to cause false injury. Immediately after injury, mice in sham injury group and ARDS alone group were injected with normal saline through the tail vein, while mice in normal cell group, ANXA1-overexpressing group, and ANXA1-knockdown group were injected with normal AMSCs, ANXA1-overexpressing AMSCs, and ANXA1-knockdown AMSCs, correspondingly. At post injection hour (PIH) 24, 5 mice in each group were selected, the Evans blue staining was performed to observe the gross staining of the right lung tissue, and the absorbance value of bronchoalveolar lavage fluid (BALF) supernatant of left lung was detected by microplate reader to evaluate the pulmonary vascular permeability. Three days after injection, the remaining 5 mice in each group were taken, the right lung tissue was collected for hematoxylin-eosin staining to observe the pathological changes and immunohistochemical staining to observe the CD11b and F4/80 positive macrophages, and the levels of tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), and IL-1β in BALF supernatant of left lung were determined by enzyme-linked immunosorbent assay. Data were statistically analyzed with paired sample t test, one-way analysis of variance, and least significant difference test. Results: At PTH 72, AMSCs in both ANXA1-overexpressing group and ANXA1-knockdown group expressed higher fluorescence intensity than AMSCs in corresponding no-load control group, respectively. At PTH 72, compared with those in corresponding no-load control group, the protein and mRNA expressions of ANXA1 in ANXA1-overexpressing group were significantly increased (wth t values of 249.80 and 6.56, respectively, P<0.05), while the protein and mRNA expressions of ANXA1 in ANXA1-knockdown group were significantly decreased (wth t values of 176.50 and 18.18, respectively, P<0.05). At PIH 24, compared with those in sham injury group (with the absorbance value of BALF supernatant being 0.041±0.009), the lung tissue of mice in ARDS alone group was obviously blue-stained and the absorbance value of BALF supernatant (0.126±0.022) was significantly increased (P<0.05). Compared with those in ARDS alone group, the degree of blue-staining in lung tissue of mice was significantly reduced in normal cell group or ANXA1-overexpressing group, and the absorbance values of BALF supernatant (0.095±0.020 and 0.069±0.015) were significantly decreased (P<0.05), but the degree of blue-staining in lung tissue and the absorbance value of BALF supernatant (0.109±0.016, P>0.05) of mice in ANXA1-knockdown group had no significant change. Compared with that in normal cell group, the absorbance value of BALF supernatant of mice in ANXA1-overexpressing group was significantly decreased (P<0.05). Three days after injection, the lung tissue structure of mice in ARDS alone group was significantly damaged compared with that in sham injury group. Compared with those in ARDS alone group, hemorrhage, infiltration of inflammatory cells, alveolar collapse, and interstitial widening in the lung tissue of mice were significantly alleviated in normal cell group and ANXA1-overexpressing group, while no significant improvement of above-mentioned lung tissue manifestation was observed in ANXA1-knockdown group. Three days after injection, the numbers of CD11b and F4/80 positive macrophages in the lung tissue of mice in ARDS alone group were significantly increased compared with those in sham injury group. Compared with those in ARDS alone group, the numbers of CD11b and F4/80 positive macrophages in lung tissue of mice in normal cell group, ANXA1-overexpressing group, and ANXA1-knockdown group reduced, with the most significant reduction in ANXA1-overexpressing group. Three days after injection, compared with those in sham injury group, the levels of TNF-α, IL-6, and IL-1β in BALF supernatant of mice in ARDS alone group were significantly increased (P<0.05). Compared with those in ARDS alone group, the levels of TNF-α, IL-6, and IL-1β in BALF supernatant of mice in normal cell group and ANXA1-overexpressing group, as well as the level of IL-1β in BALF supernatant of mice in ANXA1-knockdown group were significantly decreased (P<0.05). Compared with that in normal cell group, the level of TNF-α in BALF supernatant of mice was significantly decreased in ANXA1-overexpressing group (P<0.05) but significantly increased in ANXA1-knockdown group (P<0.05). Conclusions: Overexpression of ANXA1 can optimize the efficacy of AMSCs in treating ARDS and enhance the effects of these cells in inhibiting inflammatory response and improving pulmonary vascular permeability, thereby alleviating lung injury of mice with ARDS.

Docosahexaenoic Acid Reverses Epithelial-Mesenchymal Transition and Drug Resistance by Impairing the PI3K/AKT/ Nrf2/GPX4 Signalling Pathway in Docetaxel-Resistant PC3 Prostate Cancer Cells

Drug resistance is a serious problem in cancer therapy. Growing evidence has shown that docosahexaenoic acid has anti-inflammatory and chemopreventive abilities. Studies have shown that autophagy inhibition and ferroptosis are promising therapeutic strategies for overcoming multidrug resistance. This study was aimed to examine whether docosahexaenoic acid (DHA) could reverse docetaxel resistance in prostate cancer cells. Cell survival was examined by MTT and colony formation. Protein expression was determined by Western blot. Reactive oxygen species (ROS) production was measured by flow cytometry. DHA displayed anti-cancer effects on proliferation, colony formation, migration, apoptosis, autophagy and epithelial mesenchymal transition. Glutathione-S-transferase π is an enzyme that plays an important role in drug resistance. DHA inhibited GSTπ protein expression and induced cytoprotective autophagy by regulating the PI3K/AKT signalling pathway in PC3R cells. DHA combined with PI3K inhibitor (LY294002) enhanced apoptosis by alleviating the expression of LC3B, (pro-) caspase- 3 and (uncleaved) PARP. DHA induced ferroptosis by attenuating the expression of glutathione peroxidase 4 (GPX4) and nuclear erythroid 2-related factor 2 (Nrf2). DHA-treated PC3R cells produced ROS. The ROS and cytotoxicity were reversed by treatment with ferrostatin-1. DHA combined with docetaxel inhibited EMT by regulating the expression of E-cadhein and N-cadherin. In summary, DHA reversed drug resistance and induced cytoprotective autophagy and ferroptosis by regulating the PI3K/AKT/Nrf2/GPX4 signalling pathway in PC3R cells. We propose that DHA could be developed as a chemosensitizer and that the PI3K/AKT /Nrf2/GPX4 signalling pathway might be a promising therapeutic target for overcoming cancer drug resistance.

[Disparity of minnesota multiphasic personality inventory between positions and its relationship with job burnout in a general hospital]

Objective: To explore the difference of personality characteristics of physicians, nurses, medical skills and administrative personnel in a general hospital and its influence on job burnout. Methods: Employee entered the hospital before 2018 were enrolled in the current study and the position was classified as physicians, nurses, medical technician and administrative staff. Minnesota Multiphasic Personality Inventory (MMPI) was completed by the employee at the time of entering the hospital. Status of job burnout was assessed in 2018 using the Maslach Burnout Inventory-General Survey (MBI-GS) . Results: Physicians have a higher rate of paranoia than others (P<0.05) , and administrative staff and medical technician have a slightly higher score than the other two categories of people (P<0.05) , and administrators lie at a higher rate than others (P<0.05) . Further analysis found that personality traits did not have a significant association with job burnout at the time of entry. Conclusion: The administrative and medical staff is slightly more irritable, the administrative staff lying slightly higher score, the staff after the entry of job burnout is not affected by the personality characteristics of the onboarding.

High CpG island methylator phenotype is associated with lymph node metastasis and prognosis in gastric cancer

Several studies have found that the promoter CpG island is frequently methylated in gastric cancer. The CpG island methylator phenotype (CIMP) defines concordant methylation of multiple promoter CpG island loci in a subset of gastric cancer. However, the relationship between CIMP and lymph node metastasis in gastric cancer is unknown. Our study aimed to characterize the role of CIMP in lymph node metastasis. Clinical specimens from 120 patients were analyzed and PCR was used to detect the methylation status of five genes (ALX4, TMEFF2, CHCHD10, IGFBP3, and NPR1). We measured the level of mRNA for the five genes by real-time RT-PCR. Microsatellite instability and Helicobacter pylori infection status were assayed by capillary electrophoresis and real-time PCR, respectively. DNA methylation in the five genes was correlated with low expression of the respective mRNA. With CIMP as the dependent variable, CIMP-high gastric cancer tended to show more distant lymph node metastasis, higher pathologic tumor classification, more pathologic metastasis, and higher pathologic TNM status. Microsatellite instability and H. pylori status were not significant predictors of prognosis. CIMP-high gastric cancer showed significantly worse survival compared with that of CIMP-low/CIMP-negative gastric cancer (P < 0.001). Our results show that there is an association between CIMP status and lymph node metastasis in gastric cancer and CIMP-high was an independent prognostic factor.

(-)-Epigallocatechin-3-gallate inhibits VEGF expression induced by IL-6 via Stat3 in gastric cancer

AIM: To demonstrate that (-)-Epigallocatechin-3-gallate (EGCG) inhibits vascular endothelial growth factor (VEGF) expression and angiogenesis induced by interleukin-6 (IL-6) via suppressing signal transducer and activator of transcription 3 (Stat3) activity in gastric cancer.

METHODS: Human gastric cancer (AGS) cells were treated with IL-6 (50 ng/mL) and EGCG at different concentrations. VEGF, total Stat3 and activated Stat3 protein levels in the cell lyses were examined by Western blotting, VEGF protein level in the conditioned medium was measured by enzyme-linked immunosorbent assay, and the level of VEGF mRNA was evaluated by reverse transcription polymerase chain reaction (RT-PCR). Stat3 nuclear translocation was determined by Western blotting with nuclear extract, and Stat3-DNA binding activity was examined with Chromatin immunoprecipitation (ChIP) assay. IL-6 induced endothelial cell proliferation was measured with 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazoliumbromide assay, in vitro angiogenesis was determined with endothelial cell tube formation assay in Matrigel, and IL-6-induced angiogenesis in vitro was measured with Matrigel plug assay.

RESULTS: There was a basal expression and secretion of VEGF in AGS cells. After stimulation with IL-6, VEGF expression was apparently up-regulated and a 2.4-fold increase was observed. VEGF secretion in the conditioned medium was also increased by 2.8 folds. When treated with EGCG, VEGF expression and secretion were dose-dependently decreased. IL-6 also increased VEGF mRNA expression by 3.1 folds. EGCG treatment suppressed VEGF mRNA expression in a dose-dependent manner. EGCG dose-dependently inhibited Stat3 activation induced by IL-6, but did not change the total Stat3 expression. When treated with EGCG or AG490, VEGF expressions were reduced to the level or an even lower level in the tumor cells not stimulated with IL-6. However, PD98059 and LY294002 did not change VEGF expression induced by IL-6. EGCG inhibited Stat3 nucleus translocation, and Stat3-DNA binding activity was also markedly decreased by EGCG. Furthermore, EGCG inhibited IL-6 induced vascular endothelial cell proliferation and tube formation in vitro and angiogenesis in vitro.

CONCLUSION: EGCG inhibits IL-6-induced VEGF expression and angiogenesis via suppressing Stat3 activity in gastric cancer, which has provided a novel mechanistic insight into the anti-angiogenic activity of EGCG.

[Epigallocatechin-3-gallate inhibits growth and angiogenesis of gastric cancer and its molecular mechanism]

OBJECTIVE

To investigate the inhibitory effect of epigallocatechin-3-gallate (EGCG) on growth and angiogenesis of gastric cancer and to explore its molecular mechanism.

METHODS

Heterotopic tumor was established by subcutaneously injection with SGC-7901 cells in nude mice. Once the tumor was established, the mice were allocated randomly into two groups and received intraperitoneal injection of EGCG or phosphate buffered saline respectively. Tumor growth was measured by caliper in two dimensions, and angiogenesis was determined with tumor microvessel density (MVD) by immunohistochemistry. Protein levels of vascular endothelial growth factor (VEGF) and activation of signal transducer and activator of transcription 3(Stat3) in tumor cells and tumor tissues were examined by Western blot. VEGF release in tumor culture medium was determined by ELISA and VEGF mRNA expression in tumor cells by RT-PCR.

RESULTS

Intraperitoneal injection of EGCG significantly inhibited the growth of gastric cancer[(0.32+/-0.08) g vs(0.81+/-0.12) g, t=7.24, P<0.01], and an average of 60.4% suppression of primary tumor growth was observed. Microvessel density in tumor tissues receiving EGCG treatment was also markedly reduced(15.2+/-4.3 vs 24.6+/-6.6,t=3.41,P<0.01),and an average of 38.2% suppression was observed. EGCG treatment markedly reduced VEGF protein level in vitro and in vivo. Secretion and mRNA expression of VEGF in tumor cells were also suppressed by EGCG in a dose-dependent manner. This inhibitory effect was associated with reduced activation of Stat3. Stat3 activation was dose-dependently suppressed by EGCG in tumor cells, and an average of 53.5% reduction was observed in tumor tissues, but EGCG treatment did not change total Stat3 expression.

CONCLUSION

EGCG reduces expression of VEGF in gastric cancer by inhibiting activation of Stat3, thereby inhibits tumor growth and angiogenesis of gastric cancer.

Expression and prognostic impact of PRL-3 in lymph node metastasis of gastric cancer: its molecular mechanism was investigated using artificial microRNA interference

High PRL-3 expression had been reported to have close association with lymph node metastasis (LNM) of gastric cancer. However, the prognostic significance of highly expressing PRL-3 in LNM of human gastric cancer and the role in the metastasis remain unclear. Our study examined PRL-3 expression both in the LNM (n = 107) and in the primary lesion (n = 137) of gastric cancer, and compared the overall survival rates. RNA interference, induced by recombinant plasmid pcDNA.rPRL3-miR expressing artificial PRL-3 miRNA, was employed to knockdown PRL-3 expression in human SGC7901 gastric cancer cells. Invasion assay and migration assay in vitro were conducted to determine the role of PRL-3 in the metastasis. The role of PRL-3 in the proliferation of SGC7901 cells and tumor growth were also determined. We observed that high PRL-3 expression was more frequently detected in the LNM than in the matched primary lesion (72.9 vs. 47.7%, p < 0.001). Furthermore, the overall survival rate of the patients with high expression of PRL-3 in the LNM was significantly less than those with moderate/low expression (p = 0.003). Importantly, knockdown of PRL-3 can significantly reduce both invasion and migration potencies of SGC7901 cells (p < 0.001), and significantly suppressed the proliferation of SGC7901 cells and slowed down the tumor growth (p < 0.001). It was concluded that high expression of PRL-3 in the LNM had a negative impact on the prognosis of the patients, and plays important roles in LNM of gastric cancer and the tumor growth, which can be a potential therapeutic target and a prognostic factor.

Association of tyrosine PRL-3 phosphatase protein expression with peritoneal metastasis of gastric carcinoma and prognosis

PURPOSE

In gastric carcinoma, high expression of PRL-3, a protein tyrosine phosphatase, is associated with lymph node metastasis. We studied the relationship between PRL-3 expression and peritoneal metastasis in gastric carcinoma.

METHODS

Immunohistochemical analysis using the anti-PRL-3 antibody was done in 639 patients with gastric carcinoma including 89 with peritoneal metastases. We then compared the clinicopathologic characteristics of the PRL-3-positive and PRL-3-negative carcinomas.

RESULTS

PRL-3 was expressed in 70.4% of the primary gastric carcinomas overall; in 80.9% of the cancers with peritoneal metastasis and in 68.7% of those without peritoneal metastasis (P = 0.020). PRL-3 expression was higher in peritoneal metastasis than in the corresponding primary gastric cancers (P = 0.028). PRL-3 expression was correlated with tumor stage (coefficient = 0.343, P = 0.01) and cancer progression, including lymphatic invasion (coefficient = 0.325, P = 0.02), extent of lymph node metastasis (coefficient = 0.322, P = 0.01), and peritoneal metastasis (coefficient = 0.316, P = 0.03). Patients who were PRL-3-negative had a better survival rate than those who were PRL-3-positive at all stages (stage I: log-rank P = 0.046, Wilcoxon P = 0.048; stage II: log-rank P = 0.035, Wilcoxon P = 0.041; stage III: log-rank P = 0.027, Wilcoxon P = 0.033; stage IV: log-rank P = 0.032, Wilcoxon P = 0.030).

CONCLUSIONS

Peritoneal metastasis appears to be correlated with PRL-3 expression, tumor stage, lymphatic invasion, and extent of lymph node metastasis. PRL-3 expression was negatively correlated with prognosis in patients with gastric cancer.

(-)-Epigallocatechin-3-gallate inhibits growth of gastric cancer by reducing VEGF production and angiogenesis

AIM: To investigate the effect of (-)-epigallocatechin-3-gallate (EGCG) on growth of gastric cancer and its possible mechanism.

METHODS: Heterotopic tumors were induced by subcutaneously injection of SGC-7901 cells in nude mice. Tumor growth was measured by calipers in two dimensions. Tumor angiogenesis was determined with tumor microvessel density (MVD) by immunohistology. Vascular endothelial growth factor (VEGF) protein level and activation of signal transducer and activator of transcription 3 (Stat3) were examined by Western blotting. VEGF mRNA expression was determined by RT-PCR and VEGF release in tumor culture medium by ELISA. VEGF-induced cell proliferation was studied by MTT assay, cell migration by gelatin modified Boyden chamber (Transwell) and in vitro angiogenesis by endothelial tube formation in Matrigel.

RESULTS: Intraperitoneal injection of EGCG inhibited the growth of gastric cancer by 60.4%. MVD in tumor tissues treated with EGCG was markedly reduced. EGCG treatment reduced VEGF protein level in vitro and in vivo. Secretion and mRNA expression of VEGF in tumor cells were also suppressed by EGCG in a dose-dependent manner. This inhibitory effect was associated with reduced activation of Stat3, but EGCG treatment did not change the total Stat3 expression. EGCG also inhibited VEGF-induced endothelial cell proliferation, migration and tube formation.

CONCLUSION: EGCG inhibits the growth of gastric cancer by reducing VEGF production and angiogenesis, and is a promising candidate for anti-angiogenic treatment of gastric cancer.

Contractile responses of diabetic rat aorta to phenylephrine at different stages of diabetic duration

AIM

To investigate the time-dependent changes in contractile responses of aorta to phenylephrine (Phe) in diabetic rats and age-matched control, and its possible mechanism.

METHODS

At stages of 2-, 6-, and 12-week diabetic duration, aortic rings were studied for contractile responses to agonists in vitro.

RESULTS

At the stage of 2-week diabetic duration, contractile responses to lower concentrations of phenylephrine were increased (P < 0.05), but the maximal contraction of phenylephrine did not change. At the stage of 6-week diabetic duration, contractile responses to phenylephrine were increased (P < 0.01) at each concentration, and the maximal contraction was increased by approximately 40 %. However, at the stage of 12-week diabetic duration: 1) the maximal contractile response to Phe 10 micromol . L-1 was decreased (P < 0.05), 2) in Ca2+ free edetic acid medium, Phe 10 micromol . L-1-induced transient contraction was also decreased (P < 0.05), 3) in Ca2+ free edetic acid medium, in the presence of nifedipine 10 micromol . L-1 and Phe 10 micromol . L-1, the Ca2+ repletion-caused contraction was not different from control, 4) in normal medium, cyclopiazonic acid (CPA) 10 micromol . L-1-induced contraction was decreased (P < 0.01).

CONCLUSION

The results suggested that contractile responses to phenylephrine in diabetic rat aorta changed with the development of diabetes, and the changes of functional Ca2+ store sizes and Ca2+ entry mainly through voltage-dependent Ca2+ channels were responsible for the alterations of contractile responses to phenylephrine in diabetes.

Effects of aging and blood pressure on the structure of the thoracic aorta in SAM mice: a model of age-associated degenerative vascular changes

The effects of aging and blood pressure on the structural alterations of the thoracic aorta were examined using male, accelerated senescence-prone, short-lived SAMP11 mice or accelerated senescence-resistant, long-lived SAMR1 mice. The aortic wall thickness increased significantly by 34% in SAMR1 and by 62% in SAMP11 with advanced age. We observed branching, breakage and disorganization of the elastic lamellae, an increase in thin collagen fibrils between the medial smooth muscle cells and hypertrophy but a significant decrease in the number of medial smooth muscle cells with aging in both strains. These alterations observed in SAMP11 occurred earlier and were more exaggerated with advanced age than in SAMR1. The aortic lumen dilated gradually in SAMR1, but narrowed significantly in SAMP11 with aging. The systolic blood pressure did not differ significantly among SAMP11s aged 3-9months, or among all ages of SAMR1. However, it was elevated in SAMP11 at the terminal stage of their life. Our results suggest that the aorta in SAMR1 might reflect the physiological process of aging, whereas SAMP11 showed earlier changes due to the senescence acceleration of the vascular cells, which were exaggerated by the elevated blood pressure.

Effects of Scutellarein on diabetic rat aorta

AIM

To study the effect of Scutellarein (Scu) on the diabetic rat aorta.

METHODS

Contractile responses to phenylepherine and endothelium-dependent relaxation responses to acetylcholine (ACh) in rat aorta were investigated after streptozocin-induced 6-wk diabetes, Scu-treated streptozocin-induced diabetes, and in age-matched control in vitro.

RESULTS

1) Endothelium-dependent relaxation to ACh in diabetic rats was decreased (P < 0.01) compared with age-matched control. 2) Contractile responses to phenylepherine were increased (P < 0.01) in diabetic rats. 3) The dietary supplement of 0.5% Scu starting from 1-wk diabetes induction prevented endothelial dysfunction (P < 0.01), but the contractile responses to phenylepherine were further increased.

CONCLUSION

Scu prevented vascular endothelial dysfunction in diabetic rats, and also potentiated the contraction induced by phenylepherine.

Erigeron breviscapus prevents defective endothelium-dependent relaxation in diabetic rat aorta

We examined the endothelium-dependent relaxation response to acetylcholine (Ach) in streptozotocin-induced diabetic rat aorta at the stages of 2- and 6-wks' duration in vitro, and compared with another two groups which were treated with dietary supplement of 0.1% Aminoquanidine (AG) and 0.5% Erigeron breviscapus (EB) from 1-week of diabetes induction. At the stage of 2-wks' duration of diabetes, relaxation responses to lower concentrations of Ach in 0.3 uM phenylepherine-precontracted aortas were diminished significantly (P<0.05) compared with age-matched control, but the maximal relaxation of Ach remained unchanged. At the stage of 6-wks' duration, diabetes caused an approximately 60% (P<0.001) deficit in maximum relaxation, and this was significantly (P<0.001) prevented in AG and EB treated groups. There was an approximately 40% enhancement in the maximum contractile response to phenylepherine with diabetes (P<0.05), which was unaffected significantly by AG and EB treatments. The data suggest that the defective endothelium-dependent relaxation in diabetic rat aorta occurred as early as 2-wks' duration of diabetes, and the treatments of AG and EB could protect vascular endothelium although the deficits in vascular smooth muscle contractile responses were not protected.

Aminoguanidine supplementation delays the onset of senescence in vitro in dermal fibroblast-like cells from senescence-accelerated mice

The effects of aminoguanidine supplementation on senescence acceleration in vitro were examined in fibroblasts from the dorsal dermis of newborn SAMP11 (accelerated senescence-prone mice), and were compared to the effects in cell lines from SAMR1 (accelerated senescence-resistant) mice. Four millimolar aminoguanidine supplementation significantly delayed the senescence/crisis in cell lines from SAMP11 mice, but did not affect the senescence/crisis in cell lines from SAMR1 mice. Flow cytometric analysis of the DNA content of confluent cells revealed that aminoguanidine supplementation significantly decelerated the increase in the number of tetraploid cells until senescence/crisis. Although mean concentrations of lipid peroxides in the primary cultures did not differ significantly, considerably higher lipid peroxidation was observed in some SAMP11 cultures, and aminoguanidine supplementation reduced them to the levels in SAMRI cultures. These results strongly suggest that oxidative stress derived from polyamine catabolism may contribute to the senescence acceleration in vitro in cell lines from SAMP11 mice.

Accelerated aging of dermal fibroblast-like cells from the senescence-accelerated mouse (SAM): acceleration of changes in DNA ploidy associated with in vitro cellular aging

Accelerated changes in the DNA ploidy associated with in vitro aging were examined in fibroblast-like cells isolated from the dorsal dermis of newborn SAMP11 (accelerated senescence-prone, short-lived) mice, and were compared to changes observed in cell lines from SAMR1 (accelerated senescence-resistant, long-lived) mice. Flow cytometric analysis of the DNA content in confluent cells and chromosome analysis in mitoses revealed that the diploid cells were being replaced with tetraploid cells until a growth crisis; thereafter, hypotetraploid cells became predominant, accompanied by immortalization. The number of mitoses decreased as the crisis ensued, then increased. Although these changes were observed in the cell lines from both strains of mice, the changes occurred more rapidly and at earlier population doublings in the cell lines from the SAMP11 mice. These results suggest that the cell lines from SAMP11 mice might have higher susceptibility to factors that cause polyploidization, including oxidative stress.

Inheritance and strain distribution of a persistent hyaloid vascular system in mice

The mode of inheritance of a persistent hyaloid vascular system was investigated in an inbred strain of Senescence-Accelerated Mouse P9 (SAMP9) by conducting crosses between SAMP9 and SAMR1, a strain which shows normal regression of the hyaloid vascular system. We also examined the distribution of this abnormality in 12 inbred SAM strains and in eight commonly used inbred strains of mice. Ophthalmoscopic examination of the eyes of 5-week-old mice, which have transparent lenses, revealed the persistence of a hyaloid vascular system in only one female F1 hybrid out of 66 offspring. The observed segregation ratio of affected to unaffected mice was 25:52 in males and 37:44 in females, following the reciprocal backcross progeny between SAMP9 mice and F1 hybrids. The results of the strain distribution study indicated that 8-97% of the mice among six strains of SAM exhibited the persistence of a hyaloid vascular system, whereas the other inbred strains did not exhibit this abnormality. These observations suggest that at least two major genes may contribute to the persistence of a hyaloid vascular system, and suggest that the SAM strains comprise a group of related inbred strains.

In vitro study of the mechanisms of senescence acceleration

Accelerated senescence can be considered to be an aging process that occurs after development and maturity and is characterized by a higher rate of increase in the degree of senescence than seen in the "normal senescence process." We devised culture methods to determine precise population doublings in cultured fibroblast-like cell lines and subsequently compared the aging process, in vitro, in cell lines established from either accelerated senescence-prone or- resistant strains of mice to obtain evidence of accelerated aging. Fibroblast-like cell lines were established from the dorsal dermis of the newborn accelerated senescence-prone mice of the SAMP11 strain and from accelerated senescence-resistant mice of the SAMR1 strain. All cell lines from both strains showed senescence as evidenced by a crisis in growth; then were immortalized. However, in cell lines from the SAMP11 strain, this growth crisis occurred more rapidly and at earlier population doubling levels than in cell lines from the SAMR1 strain. The methods and materials should aid in the elucidation of mechanisms linked to accelerated senescence in mice.

Alteration of contractile properties to serotonin in gastric fundus smooth muscle isolated from streptozotocin (STZ)-induced diabetic rats

Contractile responses to serotonin (5-HT) of fundic smooth muscle strips isolated from both control and streptozotocin (STZ)-induced diabetic rats were investigated. Contrary to carbachol (CCh) which causes contractile hyperactivity in DM, 5-HT response tended to decrease in DM compared to that of the control. Pindolol (10(-5)M) increased the value of EC50 of the concentration-response to 5-HT about 2.5 times in both the control and DM. After treatment with pindolol, the maximal tension to 5-HT in DM significantly decreased compared to that of the control. Pindolol showed no effect on the contractile response to CCh. Pindolol significantly inhibited the relaxation caused by isoproterenol in DM more than in the control. Mianserin (10(-5) M) increased the EC50 of the response to 5-HT about 2-2.5 times in both groups, but did not cause a significant difference between the control and DM. The Ca(2+)-induced contraction caused hyperreactivity in DM in the presence of 10(-6) M CCh, but that in DM was not significantly different from the control in the presence of 10(-6) M 5-HT. Pretreatment of phorbol 12-myristate 13-acetate (PMA, 10(-5) M) significantly attenuated the response to 5-HT in the control, but not in DM. Results suggest that the contractile response to 5-HT in DM is related to the altered Ca2+ signal transduction system via disturbed protein kinase C (PKC) activity, and that there are alterations of receptor characteristics and of the density in 5-HT receptor subtypes, especially 5-HT1A, during DM development.

[Nd-YAG laser treatment for tracheobronchial benign lesions]

In recent 5 years, 33 cases of tracheobronchial benign lesions have been treated with the method of Nd-YAG laser via bronchoscope. The follow-up survey has shown that the curative ratio reached 66.7 percent and total effective rate came up to 78.8 percent. There was significant relationship between the therapeutic effectiveness and types of lesions (P < 0.01). It had higher cure rate in benign tumour, tuberculous granuloma and foreign body's granuloma than that of inflammatory granuloma and amyloidosis. This method is a new and effective one for treating benign pathologic changes in air passage. The indication and prevention of complications have been discussed.

[Studies of bronchoalveolar lavage cells during the airborne Klebsiella pneumoniae infection in immunocompromised mice]

We compared immunocompromised mice with normal mice during the airborne Klebsiella pneumoniae (KP) infection, to study the course and developing mechanisms of KP pneumonia. There are significant difference in the number and peaking time of PMN, the number of lymphocytes and plasma cells in the bronchoalveolar lavage fluids of different mice groups. These results indicate that the interference of immune specific and nonspecific host responses is an important variable in antibiotic efficacy and the existence of an immunomodulating cytokine network was suggested.

[Klinefelter's syndrome: report of 35 cases]

Thirty-five cases of Klinefelter's syndrome are reported. All patients had special type of chromosome of the disease. The authors deduce that the rate of sex chromosome distortion is concerned with the time of baby and the age of the mother. The special type of chromosome is reliable basis of the diagnosis in addition to the symptoms. After getting treatment with methyltestosterone, the testis of those patients could grow larger but could not produce spermatozoon. The authors found that the traditional Chinese medicine "Sheng Jing San" could not only help make testis larger but also could contribute to producing spermatozoa.

Clinical safety of long-term administration of gossypol in 32 cases

Thirty-two men have taken gossypol acetic acid for long periods (6-10 years). The users had side effects during the entire course. Serum glutamate-pyruvate transaminase (SGPT) was increased in 3 cases and persisted for more than a year. There was a downward trend in plasma potassium level during the loading phase. But, hypokalaemic paralysis did not occur. Results of semen analysis showed that the shorter the duration of gossypol administration, the higher the recovery rate. The positive rate of Et formation of peripheral blood lymphocytes was remarkably decreased. After cessation of gossypol for 6-12 months, Et formation of the group stopping drug showed a recovering trend, but had not recovered to normal. The IgG level in the serum of treatment group was decreased, but was still within normal range.