Adhesion formation in intubated rabbits increases with high insufflation pressure during endoscopic surgery

The aim of the study was to test the hypothesis that the increase in adhesion formation by CO(2) pneumoperitoneum is caused by mesothelial hypoxaemia. Therefore the effect of the intra-abdominal pressure together with the flow rate upon adhesion formation was evaluated in rabbits following laser and bipolar lesions during endoscopic surgery using humidified CO(2) at 35 +/- 1 degrees C. The intra-abdominal pressure and flow rate were 5 mmHg and 1 l/min in group 1 (n = 5), 5 mmHg and 10 l/min in group 2 (n = 4), 20 mmHg and 1 l/min in group 3 (n = 5) and 20 mmHg and 10 l/min in group 4 (n = 4) respectively. A rapid and reliable intubation method for rabbits was developed to permit high insufflation pressure. By two-way analysis of variance, total adhesion scores following a laser lesion increased with flow rate (P = 0.0003) and insufflation pressure (P = 0.002). Total adhesion scores of bipolar lesions increased with pressure (P = 0.02) but not with flow rate (P = 0.1). The total adhesion scores of laser and bipolar lesions together increased with flow rate (P = 0.005) and with insufflation pressure (P = 0.004). There was no statistical interaction between flow rate and insufflation pressure. In conclusion, the insufflation pressure in endoscopic surgery with CO(2) pneumoperitoneum is a co-factor in adhesion formation, together with desiccation.     

Hypoxaemia induced by CO(2) or helium pneumoperitoneum is a co-factor in adhesion formation in rabbits

A prospective randomized trial in a rabbit model was performed to test the hypothesis that the increase in adhesion formation following prolonged pneumoperitoneum is mediated by peritoneal hypoxaemia. Laparoscopic standardized opposing lesions were performed in uterine horns and pelvic sidewalls by bipolar coagulation and CO(2) laser in six groups of eight animals. Pure CO(2) or helium pneumoperitoneum was used for 10 (groups I and IV) or 45 min (groups II and V) to confirm the effect of duration of pneumoperitoneum and 96% of CO(2) or helium with 4% of oxygen (group III and VI) for 45 min to assess the effect of the addition of oxygen. After 7 days, adhesion formation was scored by laparoscopy. By two-way analysis of variance, total, extent, type and tenacity of adhesion scores increased (P = 0.0003, P = 0.0004, P = 0.0004 and P = 0.004) with increasing duration of pneumoperitoneum and decreased (P = 0.02, P = 0.03, P = 0.01 and P = 0.05) with the addition of oxygen. No differences were found between CO(2) and helium. In conclusion these data confirm the effect of pneumoperitoneum upon adhesions and demonstrate its reduction by oxygen, strongly suggesting that the main cause of adhesion formation is the relatively superficial hypoxaemia produced by the pneumoperitoneum.     

The mouse as a model to study adhesion formation following endoscopic surgery: a preliminary report.

Our aim was to investigate the feasibility of a mouse model to study adhesion formation following endoscopic surgery. Following preliminary studies to establish anaesthesia and pneumoperitoneum pressure, a prospective randomized study was carried out to investigate the effect of CO2 pneumoperitoneum on postoperative adhesions. In group I (control group), the duration of pneumoperitoneum was shorter than 5 min. In groups II, III and IV, pneumoperitoneum was maintained for 60 min without flow, with a continuous low flow (1 ml/min) and a continuous high flow (10 ml/min) through the abdominal cavities of the mice using non-humidified CO2, respectively. Adhesions were scored after 7 days by laparotomy. The total adhesion scores were 0.9 +/- 0.8 (n = 15) in control group, 2.4 +/- 0.8 (n = 15) (P < 0.001 versus control group) in group II with no flow, 2.6 +/- 1.3 (n = 15) (P < 0.001 versus control group) in group III with a continuous low flow and 4.3 +/- 0.9 (n = 15) (P < 0.001 versus control group and P < 0.001 versus group II and III) in group IV with a continuous high flow. In conclusion, the mouse can be used as a model to study adhesion formation following endoscopic surgery. Duration of CO2 pneumoperitoneum is a co-factor in adhesion formation.     

Peritoneal tissue-oxygen tension during a carbon dioxide pneumoperitoneum in a mouse laparoscopic model with controlled respiratory support

BACKGROUND: Previous animal studies suggested that the peritoneal environment during a carbon dioxide (CO(2)) pneumoperitoneum is hypoxic and that this may contribute to the formation of intra-abdominal adhesions or the growth of malignant cells. There is no study, however, that investigates the relationship between anaesthesia, ventilation and the laparoscopic peritoneal environment to the development of hypoxia. The objective of this study is to monitor the peritoneal tissue-oxygen tension (PitO(2)) under various conditions including anaesthesia alone, during a CO(2) pneumoperitoneum at both low and high intraperitoneal pressure (IPP), and laparotomy, in animal models with controlled respiratory support (CRS). METHODS: C57BL6 mice were divided into eight groups (n = 5) consisting of anaesthesia alone or with CO(2) pneumoperitoneum at low (2 mmHg) or high (8 mmHg) IPP or undergoing laparotomy. Groups were further subdivided into those with or without CRS with endotracheal intubation and mechanical ventilation. Over the course of the 1 h procedure, PitO(2) was continuously monitored. RESULTS: Protocol 1. The PitO(2) levels (104.2 +/- 7.8 mmHg, mean +/- SEM) in non-injured peritoneum during a CO(2) pneumoperitoneum at a low IPP were elevated approximately 2-fold over the levels during laparotomy (49.8 +/- 15.0 mmHg) in ventilated mice. Protocol 2. After insufflation with CO(2), the PitO(2) was immediately elevated and maintained at a higher level. Following laparotomy, it decreased immediately. This elevation was not seen with air insufflation. CONCLUSION: In mice, a significant elevation in PitO(2) occurs during a CO(2) pneumoperitoneum at low IPP with CRS.     

The effect of intra-abdominal pressure on the generation of 8-iso prostaglandin F2alpha during laparoscopy in rabbits

BACKGROUND: Carbon dioxide pneumoperitoneum induces peritoneal oxidative stress. The aim of this study was to verify the effect of intra-abdominal pressure on oxidative stress in the peritoneum and on post-operative adhesion formation. METHODS: Forty-one rabbits underwent laparoscopic surgery: either gasless, or with CO(2)-pneumoperitoneum at pressures of 5, 10 or 15 mmHg. Serial parietal peritoneal biopsies were taken at various time-points: immediately after reaching the abdominal cavity, 30, 60, 90 and 120 min afterwards, and 15 min after abdominal desufflation. 8-iso prostaglandin F(2alpha) (8-iso PGF(2alpha)), a marker of oxidative stresss, was assayed by enzyme immunoassay and adhesion formation was scored by second-look laparoscopy on day 14. RESULTS: The gasless group showed no significant changes in 8-iso PGF(2alpha). Conversely, significant changes occurred in CO(2)-pneumoperitoneum in a time- and pressure-dependent manner. Adhesions developed only in the CO(2)-pneumoperitoneum groups, and total adhesion score was correlated with the amount of CO(2) insufflated and intra-abdominal pressure, but not with 8-iso PGF(2alpha), which was correlated with intra-abdominal pressure. CONCLUSION: Intra-abdominal pressure increased 8-iso PGF(2alpha) in the parietal peritoneum in a graded fashion, whilst gasless laparoscopy had no impact. It also influenced the frequency and severity of adhesion formation, but no causal link was found between 8-iso PGF(2alpha) and post-operative adhesion formation.     

The persufflator: an insufflation device for laparoscopy and especially for CO2-laser-endoscopic surgery.

A new insufflation device for laparoscopic surgery has been developed which permits the persufflation of the abdominal cavity with humidified CO2 at 37 degrees C, with flow rates of 4 l/min/mm of mercury (3 l/min/cm of water) insufflation pressure, i.e. 60 l/min for an insufflation pressure of 15 mm of mercury (20 cm of water). The device consists essentially of an operative laparoscope with a large side opening of 7 mm internal diameter, and a pressure valve limiting the insufflation pressure. The device is safe, since the intraabdominal pressure can never exceed the insufflation pressure. The device has been extensively tested in greater than 500 CO2-laser-endoscopic procedures and has proven to be safe and useful. Smoke can be constantly removed and the pneumoperitoneum is unaffected even by the removal or leakage of large volumes of CO2 from the pneumoperitoneum.     

Thermoresponsive artificial extracellular matrix: N-isopropylacrylamide-graft-copolymerized gelatin

Poly(N-isopropylacrylamide)-graft-copolymerized gelatin (PNIPAM-gelatin) was prepared by iniferter-based photopolymerization of multiply derivatized dithiocarbamylated gelatin. PNIPAM-gelatins exhibited low critical solution temperature (LCST) immediately below the physiological temperature. PNIPAAm-gelatin-coated dishes induced cell adhesion at 37 degrees C but incomplete detachment at room temperature, whereas dishes coated with PNIPAM or a mixture of PNIPAAm and gelatin showed little cell adhesion. The mixture of PNIPAAm-gelatin and PNIPAAm induced cell adhesion at 37 degrees C and detachment at 20 degrees C: the degrees of cell adhesion and detachment depended on the mixed ratio of PNIPAAm-gelatin and PNIPAAm. Complete thermoresponsive adhesion and detachment were found for the mixture containing a small fraction of PNIPAAm-gelatin (approximately 5 wt% with respect to PNIPAAm; gelatin content in the mixture is 2.7 wt%). Such a mixture may serve as thermoresponsive cell matrix for fabrication of a tissue-engineered device.     

Reactive oxygen species and adhesion formation: clinical implications in adhesion prevention

Postoperative adhesion formation is a major clinical problem.It has been demonstrated that the pneumoperitoneum used duringlaparoscopy is a cofactor in adhesion formation. Reactive oxygenspecies (ROS) are produced in a hyperoxic environment and duringthe ischaemia/reperfusion process. ROS activity is deleteriousfor cells, which protect themselves by an antioxidant systemknown as ROS scavengers. ROS activity can increase by up-regulationof ROS themselves or by down-regulation of ROS scavengers. Recentdata also point to a role for ROS in adhesion formation sincethe administration of ROS scavengers decreases adhesion formationin several animal models. ROS activity increases during bothlaparotomy and laparoscopy. During laparoscopy, the pneumoperitoneumdetermines ischaemia at the time of insuflation and reperfusionat the time of deflation. During laparotomy, the environmenthas a 150 mmHg partial pressure of oxygen (pO₂), which is muchhigher than the intracellular pO₂ (5–40 mmHg). This canexplain the increase in ROS activity. The aim of this debateis to open a discussion about the importance of ROS activity,besides the known players and mechanisms involved, in adhesionformation and in adhesion prevention.     

Physiological responses to prolonged aquatic hypoxia in the Queensland lungfish Neoceratodus forsteri

The effects of moderate and severe hypoxia on air breathing frequency and respiratory properties of the blood of the Queensland (Australian) lungfish Neoceratodus forsteri were measured in fish exposed to these conditions for 14-22 days at 20 degrees C. Haemoglobin oxygen affinity increased after exposure to moderate hypoxia (PW(O(2)) = 60 mmHg), but did not increase further after exposure to severe hypoxia (PW(O(2)) = 40 mmHg). The P(50) of whole blood (20 degrees C, P(CO(2)) = 16.0 mmHg) fell from 22.0 +/- 1.5 mmHg in normoxic conditions to 19.0 +/- 1.0 mmHg in hypoxic conditions. Under both moderate and severe hypoxia, haematocrit, haemoglobin, blood lactate, and erythrocyte phosphate concentrations did not differ from normoxic values. The observed increase in haemoglobin oxygen affinity in response to aquatic hypoxia is typical of compensatory responses seen in obligate water breathers, but smaller. This suggests that the capacity of lungfish to respond to hypoxia by breathing air removes the necessity for further left-shifting of the oxygen equilibrium curve.     

The effect of temperature correction of blood gas values on the accuracy of end-tidal carbon dioxide monitoring in children after cardiac surgery

We evaluated accuracy of end-tidal carbon dioxide tension (PETco2) monitoring and measured the effect of temperature correction of blood gas values in children after cardiac surgery. Data from 49 consecutive mechanically ventilated children after cardiac surgery in the cardiac intensive care unit were prospectively collected. One patient was excluded from the study. Four arterial-end-tidal CO2 pairs in each patient were obtained. Both the arterial carbon dioxide tension (Paco2) values determined at a temperature of 37 degrees C and values corrected to body temperature (Patcco2) were compared with the PETco2 values. After the surgical correction 28 patients had biventricular, acyanotic (mean age 2.7 +/- 4.8 years) and 20 patients had a cyanotic lesion (mean age 1.0 +/- 1.7 years). The body temperature ranged from 35.2 degrees C to 38.9 degrees C. The Pa-PETco2 discrepancy was affected both by the type of cardiac lesion and by the temperature correction of Paco2 values. Correlation slopes of the Pa-PETco2 and Patc-PETco2 discrepancies were significantly different (p = 0.040) when the body temperature was higher or lower than 37 degrees C. In children, after cardiac surgery, end-tidal CO2 monitoring provided a clinically acceptable estimate of arterial CO2 value, which remained stabile in repeated measurements. End-tidal CO2 monitoring more accurately reflects temperature-corrected blood gas values.     

B/T cell ratio of rabbit peripheral blood lymphocytes. Influence of separation technique on results

Spontaneous in vitro T cell rosette formation at room temperature leading to enrichment of B cells has been reported. We tested 10 individual New Zealand White rabbits sequentially, separating the lymphocytes either at room temperature or at 37 degrees C. T cells are lost constantly at room temperature but to a lesser extent at 37 degrees C. The determination of the yield of lymphocytes after Ficoll separation gives the best control for the accuracy of the results. If lymphocytes are separated at 37 degrees C and if the yield of lymphocytes is greater than 45%, the variation in T cells is small and their number is constant between 62 and 74%. These data show that the reported wide range of T cells in rabbit peripheral blood is due to methodological errors and not inherent in the rabbit.     

SARS-CoV的培养和灭活条件的研究

目的　研究SARS CoV的大量培养和灭活方法,为制备马抗SARS免疫球蛋白制剂提供安全的病毒。方法　使用SARS CoV感染Vero、Vero E6和2BS细胞株,筛选对SARS CoV较敏感的细胞株和最佳病毒感染量;在2 5℃、33℃和37℃培养条件下,检测SARS CoV的最适培养温度。在室温下,使用1∶2 0 0 0～1∶2 0 0 0 0的β丙内酯浓度灭活SARS CoV ,观察最佳灭活时间和效果。结果　SARS CoV对Vero和Vero E6细胞株比较敏感。在37℃、5 %CO2 孵箱中培养72h ,细胞病变达75 %以上。1∶4 0 0 0的β丙内酯能够完全灭活SARS CoV。将灭活后的病毒液在2℃～8℃作用16h ,37℃水浴2h能够完全使β丙内酯的毒性水解。结论　用Vero或Vero E6细胞培养SARS CoV ,在37℃、5 %CO2 孵箱中培养72h ,病毒滴度最高。用1∶4 0 0 0的β丙内酯浓度加入病毒液中,作用1h能够完全灭活SARS CoV。     

Effects of supplemental perioperative oxygen on post-operative abdominal wound adhesions in a mouse laparotomy model with controlled respiratory support

BACKGROUND: Post-operative adhesion formation is a major clinical problem. Tissue oxygenation is one of the most important determinants in adhesion formation. The objective of this study was to investigate whether supplemental perioperative oxygen could reduce post-operative adhesion formation through increasing the peritoneal tissue oxygen tension (PitO(2)) in a mouse model. METHODS: Adult C57BJ6 mice were randomly assigned to two groups: Group 1 (n = 20), Fraction of Inspired Oxygen (FiO(2)): 0.21; Group 2 (n = 20), FiO(2): 0.80. On day 0, over the course of the 90 min procedure including the 60 min of laparotomy, PitO(2) was continuously monitored. On day 7, a second laparotomy was performed to assess abdominal wound adhesions. Real-time RT-PCR was performed to measure expression levels of tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) mRNA in peritoneal tissues. RESULTS: The PitO(2) levels in Group 2 were significantly higher compared to Group 1 (P < 0.001) and controls (P < 0.003). There was no significant difference in the incidence of abdominal wound adhesions; however, the severity of adhesions was significantly reduced in Group 2 compared to Group 1 (P < 0.03). A significantly higher tPA/PAI-1 mRNA ratio was detected in Group 2 and the controls compared to Group 1 (P < 0.02 and P < 0.002, respectively). CONCLUSIONS: Supplemental perioperative oxygen may help to reduce post-operative adhesion formation.     

Thermoresponsive artificial extracellular matrix: N-isopropylacrylamide-graft-copolymerized gelatin

Poly(N-isopropylacrylamide)-graft-copolymerized gelatin (PNIPAM-gelatin) was prepared by iniferter-based photopolymerization of multiply derivatized dithiocarbamylated gelatin. PNIPAM-gelatins exhibited low critical solution temperature (LCST) immediately below the physiological temperature. PNIPAAm-gelatin-coated dishes induced cell adhesion at 37°C but incomplete detachment at room temperature, whereas dishes coated with PNIPAM or a mixture of PNIPAAm and gelatin showed little cell adhesion. The mixture of PNIPAAm-gelatin and PNIPAAm induced cell adhesion at 37°C and detachment at 20°C: the degrees of cell adhesion and detachment depended on the mixed ratio of PNIPAAm-gelatin and PNIPAAm. Complete thermoresponsive adhesion and detachment were found for the mixture containing a small fraction of PNIPAAm-gelatin (approximately 5 wt% with respect to PNIPAAm; gelatin content in the mixture is 2.7 wt%). Such a mixture may serve as thermoresponsive cell matrix for fabrication of a tissue-engineered device.     

Oxygen supply of the blood-free perfused guinea-pig brain in normo- and hypothermia measured by the local distribution of oxygen pressure

The O2 supply of the blood-free perfused brain cortex of the guinea pig was investigated by measuring polarographically the local distribution of tissue PO2 at 18 degrees C, 24 degrees C, and 37 degrees C. The perfusion was performed in situ, using a medium equilibrated by a gas mixture of 95% O2 and 5% CO2. Papaverine was added to prevent vasoconstriction during hypothermia. To avoid measuring artefacts thin micro electrodes with a small sharpened tip of ca. 4 microns in diameter were used and a special puncturing technique was applied. The experimental results indicate the presence of a large variation of local tissue PO2. Local mean PO2 increased up to a depth of 1000 microns, reached a plateau, and then decreased towards 3000 microns. This demonstrates that the O2 supply changes in dependence of the distance of the brain surface. This may partly be caused by the special vascularization pattern of the brain cortex. As it follows from the PO2 histograms, at 24 degrees C the tissue layer between 0-2000 microns (layer I) was well supplied with oxygen, whereas at the same time the layer between 2001-3000 microns (layer II) was hypoxic. At 37 degrees C, both layers were hypoxic, but layer III showed the more pronounced tissue hypoxia. To obtain a sufficient oxygen supply the temperature had to be reduced below 24 degrees C to sufficiently decrease tissue O2 consumption: at 18 degrees C, there was no sign of hypoxia any more. In comparison with the PO2 histogram of the tissue the PO2 histogram of the pial surface was shifted to higher PO2 values.(ABSTRACT TRUNCATED AT 250 WORDS)     

A randomized, controlled pilot study of the safety and efficacy of 4% icodextrin solution in the reduction of adhesions following laparoscopic gynaecological surgery

BACKGROUND: Adhesion-related readmissions are frequent sequelae to gynaecological surgery. Attempts to prevent adhesions by separating healing peritoneal surfaces include site-specific barriers and hydroflotation by instilled solutions. Rapid absorption limits the effectiveness of solutions such as Ringer's lactated saline (RLS). This pilot study assessed the safety, tolerability and preliminary effectiveness of a non-viscous, iso-osmolar solution of 4% icodextrin, an alpha-1,4 glucose polymer with prolonged intraperitoneal residence, in reducing adhesions after laparoscopic gynaecological surgery. METHODS: Women aged > or = 18 years, requiring laparoscopic adnexal surgery (n = 62), were entered into a randomized, open-label, assessor-blinded, multicentre study to compare 4% icodextrin with RLS. Treatments were coded in blocks of four with equal randomization to each group, and pre-allocated to consecutively numbered patients. At least 100 ml per 30 min was used for intra-operative lavage, with 1 l instilled post-operatively. Per protocol analysis included all eligible patients (n = 53); reformation analysis required one or more baseline adhesion (n = 42). Incidence, extent and severity of post-operative adhesions were assessed at second-look laparoscopy after 6-12 weeks. Procedures were video-taped for third party, blinded assessment. RESULTS: Safety and tolerability (laboratory variables, adverse events, clinical follow-up) were good with no difference between treatments. A shift analysis of incidence-ranked adhesions (n = 53) showed apparent improvements in more patients with icodextrin than RLS (37 versus 15%; not significant). Adhesion score reduction (n = 42) was more frequent in icodextrin- than RLS-treated patients: incidence (52 versus 32%), extent (52 versus 47%), and severity (65 versus 37%). Despite greater baseline adhesions, median reformation was less after icodextrin (24%) than RLS (60%). The pilot study group sizes were not powered for statistical significance. CONCLUSIONS: In this preliminary study, 4% icodextrin lavage plus instillation was well tolerated and reduced adhesion formation and reformation following laparoscopic gynaecological surgery. A Phase III pivotal study is currently in progress.     

The role of arterial oxygen tension in the respiratory response to localized heating of the hypothalamus and to hyperthermia

1. Rectal temperatures, respiratory rates, arterial blood gas tensions, arterial pH and the percentage of red cells in arterial blood have been measured in the unanaesthetized ox in a cool environment (15/12 degrees C, dry bulb/wet bulb [DB/WB]), in a hot, dry environment (40/21 degrees C, DB/WB), during hyperthermia, during infra-red irradiation, and during localized heating of the anterior hypothalamus. In some experiments the gas tensions and pH of mixed venous blood, and the percentage saturation of the arterial blood with oxygen, were also measured.2. In the cool environment at a mean rectal temperature (T(r)) of 38.8 degrees C and a respiratory rate (f) of 28/min the mean values obtained from six animals were: arterial oxygen tension (P(a, O) (2)), 93 mm Hg; arterial carbon dioxide tension (P(a, CO) (2)) 42 mm Hg; arterial pH 7.49; arterial oxygen saturation (S(a, O) (2)) 94%; arterial oxygen capacity (Cap(a, O) (2)) 13.6 vol.%; arterial packed cell volume (P.C.V.) 29%.3. Exposure to the hot, dry environment resulted in a small increase in the rectal temperature and thermal polypnoea, but there were no statistically significant changes in the blood gas tensions.4. During hyperthermia statistically significant increases occurred in rectal temperature, respiratory rate, P(a, O) (2), pH and arterial haematocrit, while the P(a, CO) (2) decreased. The venous oxygen tension (P(v, O) (2)) decreased also, and the tentative conclusion was made that although the oxygenation of arterial blood remained unimpaired during hyperthermia, tissue hypoxia may supervene. At very high levels of deep body temperature, some evidence for a secondary decrease in P(a, O) (2) was obtained.5. Localized heating of the anterior hypothalamus caused an increase in respiratory rate and in P(a, O) (2). The P(v, O) (2) increased also. These changes were considered to be due to increased cardiac output and diversion of blood to the skin.6. During infra-red irradiation of three animals at an environmental temperature of 40/21 degrees C, the respiratory rate increased, but the P(a, O) (2) decreased.     

Warming Echovist contrast medium for hysterocontrastsonography and the effect on the incidence of pelvic pain. A randomized controlled study

BACKGROUND: Hysterocontrastsonography (HyCoSy) is a simple effective investigation of tubal patency. One common side effect is pelvic pain at the time of the procedure. The temperature of the contrast media used may be a causative agent for pelvic pain. This study was designed to assess the effect of warming the contrast to body temperature compared to room temperature on the incidence of pelvic pain. METHODS: A randomized controlled trial was carried out at the Cardiff Assisted Reproduction Unit. Following ethical approval, all women having HyCoSy for tubal assessment were asked if they would be willing to participate in the study. Computer-generated numbers were placed in opaque sealed envelopes, which were opened by the fertility nurse at the time of procedure. The women were randomized into two arms to receive the contrast medium at either room temperature or at body temperature. Randomization was done according to CONSORT guidelines. The pain experienced was then recorded by the patient on a 10-cm visual analogue scale. RESULTS: The mean pain scores in the room temperature and the body temperature arms were 5.1 and 3.86, respectively. This was statistically significant (P = 0.006). CONCLUSION: Warming of Echovist contrast media to body temperature is a simple and effective intervention in reducing discomfort at the time of HyCoSy.     

不同刺激剂和培养环境对CD4+、CD8+T细胞内细胞因子表达的影响

目的探讨不同的刺激剂和不同的培养条件对CD4 和CD8 T细胞内细胞因子表达的影响。方法分离正常人的外周血单个核细胞(PBMC),分别加入3种不同的刺激剂(PHA,抗CD3和抗CD28mAb,PMA和离子霉素),置于4种不同的培养环境下(室温,37℃水浴,37℃培养箱,37℃50mL/LCO2培养箱)培养4·5~5h。收集细胞,以荧光素-mAb标记后,用流式细胞术分析CD4 、CD8 T细胞内IL-2、IFN-γ和TNF-α的表达。结果CD4 和CD8 T细胞内细胞因子的表达,随着刺激剂的不同而有所差别,且在上述4种培养环境中,PMA的刺激效果最强,抗CD3mAb次之,PHA的刺激效应最弱。以上述3种刺激剂刺激后,不同培养条件对T细胞内细胞因子的表达有一定的影响。室温培养时几乎检测不到细胞因子的表达,而在37℃水浴、37℃培养箱和37℃50mL/LCO2培养箱中培养时,表达细胞因子的CD4 和CD8 T细胞的百分率差异无统计学意义(P>0.05)。结论不同刺激剂体外刺激T细胞表达细胞因子的效应不同,依次为PMA和离子霉素>抗CD3和抗CD28mAb>PHA。体外刺激培养的T细胞活化过程中,温度是重要的条件,CO2无明显影响。     

Transfundal insertion of a Veress needle in laparoscopy of obese subjects: a practical alternative.

Because induction of artificial pneumoperitoneum through the infra-umbilical route is associated with complications in laparoscopic procedures, especially in obese patients, we performed a prospective randomized study comparing the conventional infra-umbilical route with a transfundal route, in which the Veress needle is inserted into the peritoneal cavity through the uterine fundus. One hundred obese subjects (body mass index >/=25 kg/m(2)) scheduled for laparoscopic sterilization were randomized into two groups. In the infra-umbilical group pneumoperitoneum was achieved at a ratio (punctures/pneumoperitoneum) of 56/49 (1.14). There was one failure in this group. In the transfundal group the ratio was 53/51 (1.04). There was no clinically significant bleeding in either of the groups; nor were there any major complications. One subject in whom the infra-umbilical route failed was moved to the transfundal group. This subject also underwent dilatation and curettage at the time of laparoscopy. Postoperatively she contracted chlamydial pelvic inflammatory disease. No other infections were detected postoperatively in either of the groups. In conclusion, the transfundal route of inducing artificial pneumoperitoneum proved to be easy, safe and effective.