小于胎龄儿大鼠胰岛素抵抗与ghrelin水平的关系

Objective To observe the change of insulin sensitivity index (ISI) and ghrelin level, to examine their correlation and to explore the role and significance of ghrelin in insulin resistance (IR) in small for gestational age (SGA) rats. Methods The SGA models were established by starvation method in pregnant SD rats. Experimental rats were grouped by body length and/or body weight 4 weeks after birth.Experiment grouping: ( 1 )SGA group with growth catch-up (Group S 1, n=26 ); (2)SGA group without growth catch-up (Group S2, n=31 ); (3)Normal control group was composed by male rats whose mothers ate and drank freely during pregnancy (Group C, n=27). Body weight and serum ghrelin level was checked 4 weeks after birth. Body weight, serum ghrelin, fasting blood glucose and fasting insulin were tested when the rats were 12 weeks old, and then ISI was calculated. Correlation of all the indexes was analyzed. Results The ISI of 12-week-old SGA rats was significantly decreased as compared to normal control (Group S1:2.00± 0.58, Group S2:2.23±0.58 vs Group C: 3.17±0.54, both P＜0.05). Serum ghrelin level of SGA rats was decreased compared with Group C, but the disparity was not statistically significant [Group S1: (1.357± 0.548) μg/L, Group S2: (1.428±0.714) μg/L vs Group C: (1.843±0.459) μg/L,both P＞0.05 ]. Ghrelin level in 12-week-old rats presented negative correlation with fasting insulin level in blood(r=-0.836,P＜0.01 ), and positive correlation with ISI (r=0.810, P＜0.01). Conclusion The decrease of serum ghrelin level is correlated with IR in adult SGA rats. Low serum level of ghrelin may be the result of IR.     

不同压力及时间机械通气对大鼠血清白细胞介素8、白细胞介素10水平和肺组织形态学的影响

Objective To investigate the effects of mechanical ventilation with different pressure and duration on plasma IL-8 , IL-10 and lung ultrastructure in rats. Methods Thirty adult male SD rats weighting 200-220 g were randomly divided into 5 groups ( n=6 each ):control group ( group C ) , 2 h low airway pressure group (group L2, ventilated for 2 h at 15 cm H2O ) , 4 h low airway pressure group ( group L4, ventilated for 4 h at 15 cm H2O ) , 2 h high airway pressure group ( group H2, ventilated for 2 h at 25 cm H2O ) and 4 h high airway pressure group ( group H4 , ventilated for 4 h at 25 cm H2O).Mechanical ventilation was given at a rate of 40 tpm, at specified pressures for designed duration. The rats were sacrificed at 2 h or 4 h after ventilation. Blood samples were then collected and tested for levels of IL-8 and IL-10. Changes in lung ultrastructure was observed under light and electronic microscopes respectively. Results Compared with group C,the levels of IL-8 and IL-10 were significantly higher in groups L2, Lt, H2 and H4. Moreover, these levels appeared increasing along with longer duration of ventilation, with higher values in group L4 vs group L2 [IL-8: (71.5±7.6) ng/L vs (38.4±6.3) ng/L,IL-10:(364.5±18.6) ng/Lvs (271.6+21.3) ng/L, P<0.05], and in group H4 vs group H2 [IL-8: (140.7±23.5) ng/L vs (76.4±9.2) ng/L, IL-10: (472.8±22.5) ng/L vs (357.6±20.4) ng/L, P<0.05]. Over the same duration, levels of IL-8 and IL-10 were significantly greater with higher pressure used, namely, higher values in group H2 vs group L2, and in group H4 vs group L4 (P<0.05). Compared with group C, various degrees of inflammatory infiltration, emphysema, mitochondrial edema, dilated endoplama reticulum and expanded perinuclear space of lung ultrastructure existed in the other groups as shown by both light and electronic microscopes, which appeared to deteriorate along with longer ventilation time and higher pressure. Conclusions Higher pressure and longer duration for mechanical ventilation may induce IL-8 and IL-10, and also deteriorate lung tissue injury. Effective control of ventilation pressure and duration may ameliorate inflammation and injury of lung tissue.     

全反式维甲酸对人结肠癌LoVo细胞化疗药物敏感性及Survivin基因表达的影响

Objective To study the effects of all-trans-retinoic acid (ATRA) on chemotherapeutics sensibility and expression of Survivin in human LoVo colon cancer cell line, and to provide a theoretical basis for clinical application of ATRA.Methods Flow cytometer (FCM) was used to detect the cell cycle of LoVo colon cancer cell line after treated with various dose of ATRA (10-5 mol/L, 10-6 mol/L and 10-7 mol/L)for 24 h, 48 h, 72 h, 5 d, 9 d and 15 d respectively.The cells were divided into ATRA group (10-6 mol/L)and control group (cultured in routine medium RPMI1640).Meanwhile, each group were divided into subgroups respectively treated with 0 g/L, 2 g/L, 4 g/L and 6 g/L 5-fluorouracil(5-FU) , or with 0 mg/L, 200 mg/L, 400 mg/L and 600 mg/L mitomycin (MMC).MTT assay was used to detect the viability of cells so as to analyze the change in chemotherapeutics sensibility.Drug interactions were analyzed according to the interaction effects.Staining with acridine orange (AO) and ethidium bromide (EB) was used to study the apoptosis in control group(RPMI1640) , ATRA group (10-6 mol/L), 5-FU group (4 g/L), MMC group (400 mg/L), ATRA (10-6 mol/L) + 5-FU (4 g/L) group and ATRA (10-6 mol/L) + MMC (400 mg/L) group.The expression of Survivin in the LoVo cell line was investigated by immunofluorescence technique.Results Compared with the control group, the percentage of cell in Go-G1 phase increased after interference with various doses of ATRA for 24 hours, peaked at 48 h, and gradually decreased afterwards, while the percentage of cells in stages S and G2-M decreased, reach the trough at 48 h, and then increased gradually.Effects of 10-6 mol/L ATRA were most significant at all time spots.Compared with control group, 10-6 mol/L ATRA reduced cell survival rate (P＜0.05),and the survival rates in control subgroups treated with various doses of 5-FU were significantly higher than those in ATRA group (all P＜0.05).In MMC-treated control group, cell survival rate with 200 mg/L MMC was lower than that in ATRA group (0.72±0.02 vs 1.03±0.13, P＜0.05) , while treatment with 400 mg/L or 600 mg/L MMC did not result in lower cell survival compared with the ATRA group (0.52±0.05 vs 0.39±0.02, 0.36±0.02 vs 0.36±0.01, all P>0.05).Positive interactions of 10-6 mol/L ATRA with 5-FU (2 g/L, 4 g/L, 6 g/L) or MMC (200 mg/L, 400 mg/L) were found.Under fluorescence microscope, cells in ATRA + 5-FU group and ATRA + MMC group showed significantly small size, pyknosis and chromatin condensation and formation of apoptotic bodies when compared with control group, ATRA group, 5-FU group and MMC group.Expression of Survivin was inhibited after 10-6 mol/L ATRA treatment for 48 h compared with control group (33.33% vs 27.96% , P＜0.05).Conclusion ATRA enhances the chemosensibility of LoVo colon cancer cell line to 5-FU and MMC,and induces cell apoptosis, potentially through inhibition of Survivin gene expression.     

肌力训练对脑卒中恢复期偏瘫患者大腿表面肌电的影响

Objective To explore the effect of muscle strength exercise on surface electromyography (sEMG) over thigh in stroke patients with hemiplegia during convalescence so as to gain objective evidence for rehabilitation therapy of stroke patients. Methods Thirty-five stroke patients with hemiplegia during convalescence were enrolled in this study, and were divided into two groups, treatment group (n=19) and control group (n=16). The treatment group underwent muscle strength exercise for 6 weeks. Before and after treatment, sEMG signals over vastus medialis (VM), rectus femoris muscle (RF),vastus lateralis (VL), biceps femoris (BF) and semitendinosus (ST) and semimembranosus (SM) during maximal isometric voluntary contraction (MIVC) of the affected knee extension and flexion were recorded.Torque of knee joint extension and flexion, root mean square (RMS) and co-contraction ratio (CR) were computed. No rehabilitation training was performed in control group. The above mentioned indexes of control group were also recorded. Results After treatment, obvious changes were observed in MIVC torque of the affected knee flexion [ (18.02±6.52) nm vs (13.12±5.79) nm, P＜0.05] and extension [ (45.72±17.21 ) nm vs (34.76± 17.19) nm, all P＜0.05 ]. There were no significant differences in CR of flexion and extension. No statistical difference was observed in MIVC torque and CR of flexion and extension before and after treatment in control group (all P＞0.05). RMS value significantly improved when RF, VL, ST and SM over affected thigh were agonist after treatment [ (146.60±60.85) μV vs (97.02±57.17) μV, (172.65±60.73) μV vs ( 131.46 ± 52.15 ) μV, ( 188.69 ± 89.60) μV vs ( 130.57 ± 73.76) μV, all P＜0.05 ]. There were no significant differences of RMS value in the VM and BF before and after treatment (all P＞0.05), and no RMS changes were noted in control group (all P＞0.05). Conclusions Strength exercise may improve strength of flexion and extension over lower limbs in stroke patients with hemiplegia during convalescence, however, it will not induce abnormal contraction of flexion and extension. sEMG combined with torque measurement may assess functional status of hemiplegic limbs effectively.     

丙泊酚镇静下瑞芬太尼抑制喉罩置管和气管插管心血管反应的半数有效浓度比较

Objective To measure the medium effective concentration (EC50) of remifentanil for blunting cardiovascular response to placement of LMA-Fastrach, LMA-Proseal and tracheal intubation, and to compare the change of brain bispectral index (BIS) during these procedures. Methods Sixty-three patients (ASA I-II) scheduled for cholecystectomy under general anesthesia were enrolled. According to different options of intubation, all the patients were randomly allocated into three groups (n=21 each): group T by laryngoscope and tracheal intubation, group F by LMA-Fastrach and group P by LMA-Proseal.Initially, a target plasma concentration of 4 mg/L propofol was chosen, and was adjusted to maintain BIS between 45 and 55. Then, the effect-site concentration of remifentanil was started at designed concentration according to Minto's pharmacokinetic model. Five minutes later, 0.6 mg/kg (2 ED95) rocuronium was given, and intubation was performed 2 min after rocuronium administration. The pre- and post-induction mean arterial pressure (MAP), heart rate (HR) and BIS were compared among these groups. MAP and HR at 1 and 2 min pre-intubation and at 5 min post-intubation were also recorded to evaluate whether there was a cardiovascular response in these patients. Subsequently, the EC50 of remifentanil for blunting the cardiovascular response to 3 options of intubation was calculated using the Dixon-Mood up- and down- sequence. Results Compared with pre-induction, all the patients in 3 groups experienced significantly lower post-inductive MAP and HR [MAP of pre- and post-induction in T, F, P groups were (87.9±10.5) mm Hg vs (71.6±9.0) mm Hg, (91.8±8.8)mm Hg vs (73.5±9.9) mm Hg, (87.2±10.2) mm Hg vs (70.9±8.6) mm Hg, HR of pre- and post-induction in T, F, P groups were (78.8±11.6) min-1 vs (68.7±8.5) min-1,(74.8±10.3) min-1 vs (64.1±6.7) min-1, (76.7±8.2) min-1 vs (67.3±8.3) min-1,1 mm Hg=0.133 kPa, P<0.05] but BIS unchanged basically (P>0.05). The EC50 of remifentail for blunting cardiovascular response to intubation was 4.47 μg/L for group T, 4.78 μg/L for group F and 2.05 μg/L for group P, respectively. Conclusion EC50 of remifentail for blunting cardiovascular responses to intubation as shown by Minto's model appears slightly higher in LMA-Fastrach than that in tracheal intubation, and the lowest is in LMA-Proseal intubation.     

肝细胞生长因子激活胶原降解途径逆转心肌纤维化

Objective To study the effects of hepatocyte growth factor (HGF) on angiotensin Ⅱ(Ang Ⅱ )-induced synthesis and degradation of cardiac fibroblast collagen in neonatal mice.Methods Cardiac fibroblasts (CFs) of neonatal Sprague-Dawley (SD) rats were isolated by differential adhesion, and were identified by immunocytochemistry.The cells were assigned to normal control group (group C) , 10-6 mol/L Ang Ⅱ group (group A), 10μg/L HGF + 10-6 mol/L Ang Ⅱ group (group H1) and 100μg/L HGF +10-6 mol/L Ang Ⅱ group (group H2).All the groups were treated for 48 h.Hydroxyproline assay was used to determine the collagen protein level.RT-PCR was used to detect the expression of ColⅠ, ColⅢ, matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-l) mRNA, and Western blotting was employed to measure Col I protein.In addition, MMP-1 activity was evaluated by collagenase Ⅰ activity assay kit.Results After intervention for 48 h, the collagen protein levels in groups A and H1 were significantly higher compared with group C [ (39.08±2.71) mg/L vs (37.45±4.22) mg/L vs (23.73 ±±1.62) mg/L, all P＜0.05] and the collagen protein level in group H2 [(26.03±3.04) mg/L] was lower than those of groups A and Hl(P＜0.05), but was not statistically different from group C.The expression levels of Col Ⅰ ,Col M and TIMP-1 showed an order of group A＞group HI＞group H2> group C (all P＜0.05), and for MMP-1 mRNA, group A ＜ group H1 ＜ group H2 ＜ group C (all P＜0.05).The levels of Col I protein expression showed an order of group A＞group HI＞group H2＞group C (89.90±4.29 vs 68.21?1.43 vs 36.08?.8 vs 30.14?.36, all P＜0.05).The expression and activity of MMP-1 mRNA in group A and H1 were obviously lower than those in group C (all P＜0.05), while group H2 were comparable to group C in these data.Conclusion HGF re-regulates MMP-1-TIMP-1 balance and ameliorates myocardiac fibrosis mainly by activating collagen degradation.     

Gene delivery of SOCS3 protects mice from lethal endotoxic shock

Suppressor of cytokine signaling 3 (SOCS3) was reported as a feedback inhibitor of cytokine receptor signaling byinhibiting the JAK-STAT signal transduction pathway.We sought to test the anti-endotoxic septic shock effect ofliposome mediated gene delivery of SOCS3 in a lethal endotoxic shock mouse model.BALB/c mice were injectedintraperitoneally with 200 μg pcDNA3.1-SOCS3 cationic liposomes,while pcDNA3.1-IL-10 and empty vector aspositive and negative control respectively.Forty-eight hours after gene delivery,mice were challenged with 4 μg ofE.coli 0127:B8 LPS and 18 mg D-GaIN administered i.p.90 min later,serum TNF-α level was determined.Survivalover the next 48h was evaluated.Peritoneal macrophages from survival mice were stimulated in vitro with 1 μg/mlLPS for 18h,and the supernatants were harvested for determination of the amount of TNF-α.We found that genedelivery of SOCS3 significantly increase the mouse survival rate from 27.8±9.6% of control group to 61.1±9.6%(p<0.01).In comparison with control group (218±13pg/ml) and sham delivery group (219±22pg/ml),genedelivery of SOCS3 reduced the level of serum TNF-α(68±9pg/ml) significantly(p<0.01).Furthermore,genedelivery of SOCS3 displayed the capacity of prevention of tolerance of peritoneal macrophages to LPS.Thesefindings suggest that gene delivery of SOCS3 mediated by liposome is a promising approach for endotoxic septicshock treatment.Cellular & Molecular Immunology.2005;2(5):373-377.     

酵母多糖在Wistar大鼠真菌性眼内炎中的致病作用

Objective To investigate the histopathologic features, changes of blood-ocular barrier and the expression of tumor necrosis factor-α (TNF-β) and interleukin-1β(IL-1β in vitreous body of Wistar rats with zymosan-induced endophthalmitis.Methods Random number table method was used to assign the Wistar rats into saline control group (SC group,n=168) and endophthalmitis group (EO group,n=168).Rats of EO group received intravitreal injection of zymosan to induce endophthalmitis, while the control rats received injection of equivalent-ose sterile saline.The rat eyes were observed for signs of ocular inflammation and enucleated for histopathological examination at 6 h, 12 h, 1d, 2d, 3d, 5d and 7 d after injection respectively.Furthermore, aqueous humor for determination of protein levels and vitreous body for levels of TNF-α and IL-1βwere collected.Results Severe inflammatory response in the eyes was observed in EO group within 6 h to 3 d after zymosan injection, and was basically resolved after day 7.A peak intraocular leucocyte count was observed in EO group on day 1 [(482.63 ±91.15) cells/eye] that rapidly declined on day 3[(131.25±7.95) cells/eye].The increased levels of TNF-α and IL-1βin EO group peaked at 24 h after injection [TNF-α: (331.17±9.81) ng/L, IL-1β (2 156.09± 440.27) ng/L, respectively], persisted to 48 h after injection, and began to decline rapidly afterwards.On day 7 after injection, levels of TNF-α and IL-1βreturned to baseline[TNF-α: (5.55±2.27)ng/L, IL-1∞ (43.66±8.73) ng/L, respectively].Compared with SC group 6 h after injection, significantly higher protein levels in aqueous humor were detected in the EO group at all the time points (all P＜0.01).Conclusions Acute experimental endophthalmitis was successfully induced in the Wistar rats with intravitreal injection of zymosan.Massive leucocyte intraocular infiltration, blood-ocular barrier breakdown and high levels of TNF-α and IL-1βexpression in vitreous body may be the major pathologic characteristics in this experimental endophthalmitis model.     

Level of functioning of siblings and parents of probands of varying degrees of retardation

A further analysis of already published data supports the position that retardates of low ability level less frequently have retarded siblings, retarded parents, and parents low in occupational level than do retardates higher in ability level. The analysis supports the position that there are two types of retarded individuals, persons retarded as a result of gene or chromosomal anomalies, brain injury, etc., who more frequently occur in the lower-level retardate group, and persons whose retardation represents polygenic segregation, who more frequently occur in the higher-level group.     

Modes of Inheritance of Errors of Refraction

Eighteen families in which both parents had refractions within the range of +4·0 D to −4·0 D and axial lengths seen in emmetropia (22·3-26·0 mm) showed coefficients of correlation of the order 0·5 indicative of polygenic inheritance. Such coefficients were seen for axial length (0·407) and for the cornea (0·487), but not for the lens (which is known to be yoked to the axial length). No such coefficients were seen in 19 families in which one of the parents had axial length outside the emmetropic range (nine families with long axes and 10 with short axes).

The pattern of polygenic inheritance for emmetropia (completely correlated optical components) and errors of refraction up to 4·0 D (inadequately correlated components: correlation ametropia) follows that seen in stature and other measurable characters. In contrast the high refractive errors with their abnormal axial lengths (component ametropia) are—like the extremes in stature—pathological anomalies with monofactorial inheritance.

     

Aspects of the problem of direct introduction of Standards of International Organizations

Editorial note. This article is published as part of a discussion. Particular issues of the article are disputable. First of all, this concerns the so-called “folder” method of introduction of international standards for medical devices to domestic medical practice (i.e., by direct translation of the standards and their publication as standardizing documents). Nevertheless, at least one of the problems, the problem of coordination between domestic state standards for medical devices and international recommendations of ISO and IEC, is undoubtedly of topical importance. Advancement of new health service legislation which is to be approved by law-makers will definitely introduce corrections into the present situation. The Editorial Board of Meditsinskaya Tekhnika believes this article will lessen these problems and to be welcomed by readers.