[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-1ß 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-1ß 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-1ß in BALF supernatant of mice in normal cell group and ANXA1-overexpressing group, as well as the level of IL-1ß 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.

[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.

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.

[Epidemiological characteristics and outcome analysis of 266 patients with inhalation injuries combined with total burn area less than 30% total body surface area].

Objective: To explore the epidemiological characteristics and treatment outcomes of patients with inhalation injuries combined with total burn area less than 30% total body surface area (TBSA). Methods: A retrospective observational study was performed on medical records of 266 patients with inhalation injuries combined with total burn area less than 30%TBSA who were admitted to the First Affiliated Hospital of Naval Medical University from January 2008 to December 2016 and met the inclusion criteria. The following statistical data of the patients were collected, including gender, age, injury site, injurious factors of inhalation injury, degree of inhalation injury, combined total burn area, tracheotomy, time of tracheotomy, mechanical ventilation, whether stayed in intensive care unit (ICU) or not, microbial culture results of bronchoalveolar lavage fluid, length of hospital stay, length of ICU stay, mechanical ventilation days, and respiratory tract infections. Single factor and multivariate linear regression analysis were used to screen out the risk factors impacting the length of hospital stay, length of ICU stay, and mechanical ventilation days of patients. Single factor and multivariate logistic regression analysis were used to screen out the risk factors impacting respiratory tract infections of patients. Results: The 266 patients included 190 males and 76 females, with the majority age of above or equal to 21 years and below 65 years (217 patients). The major injury site was confined space. The major factor causing inhalation injury was hot air. Mild and moderate inhalation injuries were more common in patients. The combined total burn area was 9.00% (3.25%, 18.00%) TBSA. In 111 patients who had tracheotomy, most of them received the procedures before being admitted to the First Affiliated Hospital of Naval Medical University. The length of hospital stay of patients was 27 (10, 55) days. The length of ICU stay of 160 patients who were hospitalized in ICU was 15.5 (6.0, 40.0) days. The mechanical ventilation days of 109 patients who were conducted with mechanical ventilation were 6.0 (1.3, 11.5) days. A total of 119 patients were diagnosed with respiratory tract infections, with 548 strains including 35 types of pathogens isolated, mainly Gram-negative bacteria. Single factor linear regression analysis showed that age, injurious factors of inhalation injury, combined total burn area, degree of inhalation injury (moderate and severe), tracheotomy, mechanical ventilation, and respiratory tract infections were the factors impacting the length of hospital stay of patients (ß=-0.198, -0.224, 0.021, 0.127, 0.164, -0.298, 0.357, 0.447, 95% confidence interval (CI)=-0.397--0.001, -0.395--0.053, 0.015-0.028, 0.009-0.263, 0.008-0.319, -0.419--0.176, 0.242-0.471, 0.340-0.555, P<0.1). Multivariate linear regression analysis showed that with mechanical ventilation and respiratory tract infections were the independent risk factors impacting the length of hospital stay of patients (ß=0.146, 0.383, 95% CI=0.022-0.271, 0.261-0.506, P<0.05 or P<0.01). Single factor linear regression analysis showed that injurious factors of inhalation injury, combined total burn area, degree of inhalation injury (moderate and severe), tracheotomy (no tracheotomy and prophylactic tracheotomy), mechanical ventilation, and respiratory tract infections were the factors impacting the length of ICU stay of patients (ß=0.225, 0.008, 0.237, 0.203, -0.408, -0.334, 0.309, 0.523, 95% CI=0.053-0.502, 0.006-0.010, -0.018-0.457, -0.022-0.428, -0.575--0.241, -0.687--0.018, 0.132-0.486, 0.369-0.678, P<0.1). Multivariate linear regression analysis showed that with respiratory tract infections was the independent risk factor impacting the length of ICU stay of patients (ß=0.440, 95% CI=0.278-0.601, P<0.01). Single factor linear regression analysis showed that injury site, injurious factors of inhalation injury (smoke and chemical gas), combined total burn area, degree of inhalation injury (moderate and severe), tracheotomy (no tracheotomy and prophylactic tracheotomy), and respiratory tract infections were the factors impacting mechanical ventilation days of patients (ß=-0.300, 0.545, 0.163, 0.005, 0.487, 0.799, -0.791, -0.736, 0.300, 95% CI=-0.565--0.034, 0.145-0.946, 0.051-1.188, 0.001-0.009, 0.127-0.847, 0.436-1.162, -1.075--0.508, -1.243--0.229, 0.005-0.605, P<0.1). Multivariate linear regression analysis showed that smoke inhalation, severe inhalation injury, and respiratory tract infections were the independent risk factors impacting mechanical ventilation days of patients (ß=0.210, 0.495, 0.263, 95% CI=0.138-0.560, 0.143-0.848, 0.007-0.519, P<0.05 or P<0.01). Single factor logistic regression analysis showed that age, injury site, combined total burn area (10%-19%TBSA and 20%-29%TBSA), degree of inhalation injury (moderate and severe), tracheotomy (prophylactic tracheotomy and no tracheotomy), and mechanical ventilation were the factors impacting respiratory tract infections of patients (odds ratio=1.079, 0.815, 1.400, 1.331, 1.803, 1.958, 0.990, 0.320, 3.094, 95% CI=0.840-1.362, 0.641-1.044, 1.122-1.526, 1.028-1.661, 1.344-2.405, 1.460-2.612, 0.744-1.320, 0.241-0.424, 2.331-4.090, P<0.1). Multivariate logistic regression analysis showed that with mechanical ventilation was the independent risk factor impacting respiratory tract infections of patients (odds ratio=4.300, 95% CI=2.152-8.624, P<0.01). Conclusions: The patients with inhalation injuries combined with total burn area less than 30%TBSA are mainly young and middle-aged males. Smoke inhalation, degree of inhalation injury, with mechanical ventilation and respiratory tract infections are the factors that affect the outcomes of patients with inhalation injuries combined with total burn area less than 30%TBSA. Additionally, prophylactic tracheotomy shows its potential value in reducing respiratory tract infections in patients with moderate or severe inhalation injuries.

MiRNA-27a-3p promotes osteogenic differentiation of human mesenchymal stem cells through targeting ATF3.

OBJECTIVE: To elucidate whether miRNA-27a-3p can promote osteogenic differentiation of hMSCs by targeting ATF3, thus alleviating osteoporosis symptoms. PATIENTS AND METHODS: The serum levels of miRNA-27a-3p in osteoporosis patients (n=20) and normal controls (n=20) were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Human bone marrow mesenchymal stem cells (hMSCs) were subjected to osteogenic differentiation for 1, 3 and 7 days. Subsequently, mRNA levels of miRNA-27a-3p, ALP, and Bglap in hMSCs were determined by qRT-PCR. The regulatory effects of miRNA-27a-3p levels and the mRNA levels of ALP, Bglap, and Runx2 were detected. After the overexpression or knockdown of miRNA-27a-3p, we evaluated the changes in the osteogenic differentiation by alizarin red staining and ALP staining. Through Dual-Luciferase Reporter Gene Assay, we verified the binding relationship between miRNA-27a-3p and ATF3. Rescue experiments were finally conducted to prove whether miRNA-27a-3p regulated the osteogenic differentiation by targeting ATF3. RESULTS: The serum level of miRNA-27a-3p remained lower in osteoporosis patients relative to controls. With the prolongation of osteogenic differentiation, the mRNA levels of miRNA-27a-3p, ALP, and Bglap gradually increased. The overexpression of miRNA-27a-3p upregulated mRNA and the protein levels of osteogenesis-related genes, increased ALP activity, and enhanced mineralization capacity. The knockdown of miRNA-27a-3p obtained the opposite trends. MiRNA-27a-3p could target ATF3, and the overexpression of ATF3 reversed the promotive effects of miRNA-27a-3p on osteogenic differentiation. CONCLUSIONS: MiRNA-27a-3p promotes the differentiation of hMSCs into osteoblasts by targeting ATF3, thus alleviating osteoporosis symptoms.

[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.

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.