Intraperitoneal injection of cultured mesothelial cells decrease CO2 pneumoperitoneum-enhanced adhesions in a laparoscopic mouse model

Mesothelial cells are involved in peritoneal repair, and they modulate adhesion formation. Intraperitoneal injection of cultured mesothelial cells can decrease adhesion formation. The importance of the amount of cells, of the culture methods or of the origin of the cells is still unknown. Female Balb/c mice were used in a CO₂ pneumoperitoneum-enhanced adhesion formation model. Mesothelial cells were obtained from Balb/c mice and cultured over a 3-week period. Following a pilot experiment (n = 10) with injection of 400,000 mesothelial cells a dose–response study was performed with 400,000; 133,000; and 44,000 cells (n = 40). Adhesion formation decreased after the injection of cultured mesothelial cells as evidenced in the first (proportion p < 0.046, total adhesions: NS) and second experiment (p < 0.001 for proportion and total adhesions). The reduction was moreover dose dependent with a half maximal effect with some 100,000 cells. Intraperitoneal injection of cultured mesothelial cells can decrease CO₂ pneumoperitoneum-enhanced adhesion formation in mice and the effect is dose dependent, the half maximum effect being obtained with some 100,000 cells, a number which is surprisingly similar to the number of cells harvested from one mouse.     

Role of CO(2) pneumoperitoneum-induced acidosis in CO(2) pneumoperitoneum-enhanced adhesion formation in mice

The effect of assisted ventilation and CO(2) pneumoperitoneum during laparoscopic surgery upon blood gases and adhesion formation were evaluated in mice. We confirmed that the CO(2) pneumoperitoneum induces acidosis and enhances adhesion formation, and an association between both effects was demonstrated, together with its modulation by the assisted ventilation.     

Pathogenesis of CO(2) pneumoperitoneum-induced metabolic hypoxemia in a rabbit model

STUDY OBJECTIVE: To investigate the effects of carbon dioxide (CO(2)) pneumoperitoneum-induced changes in blood gases, acid-base balance, and oxygen homeostasis in rabbits. DESIGN: Prospective, randomized, controlled study (Canadian Task Force classification I). SETTING: University training and teaching center. SUBJECTS: Twenty-six adult female New Zealand white rabbits. INTERVENTION: Anesthesia and pneumoperitoneum. MEASUREMENTS AND MAIN RESULTS: In anesthetized rabbits arterial blood gases, acid-base balance, oxygenation values, and lactate concentrations were assayed during 2 hours. Spontaneous breathing, superficial and optimal ventilation without pneumoperitoneum, and with pneumoperitoneum at low (6 mm Hg) and higher (10 mm Hg) insufflation pressures were compared. The CO(2) pneumoperitoneum profoundly affected blood gases, acid-base balance, and oxygen homeostasis. Carboxemia with increasing end-tidal CO(2) and partial pressure of CO(2) (p <0.001), acidosis with decreasing pH (p <0.001), and base deficiency with decreasing actual base excess (p <0.001), standard base excess and standard bicarbonate and acid excess with increasing hydrogen bicarbonate (p <0.05 and <0.01) were found. Desaturation (p <0.01) with decreasing oxyhemoglobin p <0.05) and hemoglobin oxygen affinity (p <0.01) were also found. Carboxemia with acidosis was more pronounced with higher (p <0.01) than with lower (p >0.05) intraperitoneal pressures, and also with spontaneous breathing (p <0.05) and superficial ventilation (p <0.001) than with optimal ventilation, resulting in metabolic hypoxemia. CONCLUSION: In superficially ventilated and spontaneously breathing rabbits, CO(2) pneumoperitoneum profoundly affected blood gases, acid-base balance, and oxygen homeostasis, resulting in metabolic hypoxemia. With optimal ventilation and low intraperitoneal pressure carboxemia, respiratory acidosis, and changes in oxygen metabolism were minimal.     

Assessment of intraperitoneal adhesion formation in a rat model: can a procoagulant substance prevent adhesions?

Previous studies have shown oxidized cellulose to decrease adhesion formation in rats. A recent report showed a decrease in adhesions after application of a fibrin sealant containing thrombin, fibrinogen, and aprotinin, raising the question of whether procoagulants block adhesions by something other than a mechanical barrier effect. To assess the value of a procoagulant in preventing adhesion formation, we compared the efficacy of thrombin with that of oxidized cellulose in decreasing postoperative adhesions in rats. Eighty-five Sprague-Dawley rats underwent midline abdominal incisions and subsequent removal of a small area of right anterior abdominal wall peritoneum. Defects were left open or were closed with interrupted sutures and then treated with thrombin, oxidized cellulose, or nothing. Results obtained at postmortem seven days later showed a decrease in adhesion number and severity among animals treated with oxidized cellulose. No such effect was noted in the thrombin group. No treatment increased adhesion formation. We conclude that although oxidized cellulose appears to be of some benefit in decreasing postoperative adhesion formation in the rat, thrombin alone shows no similar effect. Further conclusions regarding adhesion induction, histologic correlates of adhesion formation, and validity of some methods of adhesion analysis are also addressed.     

Efficacy of a strategy to prevent neonatal early-onset group B streptococcal (GBS) sepsis

BACKGROUND: Existing guidelines recommend different strategies to prevent early-onset neonatal GBS sepsis. In 1997, using our own data on incidence and risk factors, we established a new prevention strategy which includes GBS screening at 36 weeks' gestation and intrapartum antibiotic prophylaxis (IAP) in women with positive or unknown GBS colonization with at least one risk factor. The present study evaluates the efficacy of the new prevention strategy. METHODS: Retrospective study of the incidence of early-onset GBS sepsis among all live births at the University Women's Hospital Basel between 1997 and 2002. Additional analysis of delivery and post partum period of all GBS sepsis cases, including GBS screening, risk factors during labor (prematurity, rupture of membranes (ROM) <12 h, intrapartum signs of infection), and IAP. Comparison of this group's characteristics G2 (9,385 live births, using the new strategy) with the previous group, G1 (1984-1993, 16,126 live births, without GBS screening or routine IAP) was performed. RESULTS: The incidence of early-onset GBS sepsis was reduced from 1/1000 (G1) to 0.53/1000 (G2). We observed a significant reduction of overall intrapartum risk factors in cases of GBS sepsis. CONCLUSION: This study suggests that our new prevention strategy is effective in reducing the incidence of early-onset GBS sepsis in neonates. In comparison, implementation of the CDC's prevention strategy might have prevented 2 additional cases in 9385 live births. However, this would have required treating a much larger number of pregnant women with IAP with consequential increasing costs, side effects and complications.     

Expression of hypoxia-inducible 2 (HIG2) protein in uterine cancer

For both cervical cancer (UCC) and endometrial cancer (EMC) there are no effective prognostic markers. In this study, we evaluated HIG2 protein expression in 332 uterine cancers (186 UCCs and 146 EMCs) and examined the relationship between HIG2 protein expression and clinical factors, including prognosis. Totally, HIG2 expression was detected in 58% of UCC and 66% of EMC. However, there was no significant relationship between HIG2 expression and age, clinical stage and histology in either UCC or EMC. In addition, HIG2 protein expression was not related to prognosis of UCC or EMC. The positivity rate of HIG2 protein was 56% and 61% in early-stage UCC and EMC, respectively and 67% in non-squamous cell carcinoma of UCC. The positivity rate of HIG2 protein was high even in early-stage UCC and EMC     

Plasma catecholamine responses during laparoscopic gynecologic surgery with CO(2) insufflation

STUDY OBJECTIVE: To compare adrenergic-sympathetic responses during pelvic laparoscopic surgery with CO(2) insufflation with those during laparotomy. DESIGN. Prospective study (Canadian Task Force classification II-1). SETTING: Tertiary care university hospital. PATIENTS: Twenty-one infertile women with a clinical diagnosis of endometriosis. INTERVENTION: Plasma norepinephrine (NE) and epinephrine (E) levels were measured in patients undergoing laparoscopic or open pelvic surgery. MEASUREMENTS AND MAIN RESULTS: During laparoscopic surgery, increases in NE and E levels were correlated with arterial tension of CO(2) (PaCO(2)) and were greater in patients with a larger increase in PaCO(2) than in those undergoing laparotomy. Hemodynamic changes were also more evident during laparoscopic surgery, with larger PaCO(2) increases. CONCLUSION: The PaCO(2) increases due to CO(2) insufflation are associated with adrenergic-sympathetic activation and hemodynamic changes during laparoscopic pelvic surgery.     

Measurement of CO(2) hypothermia during laparoscopy and pelviscopy: how cold it gets and how to prevent it.

STUDY OBJECTIVE: To evaluate intraabdominal CO(2) temperature during a variety of standard operative laparoscopy procedures with different insufflators (BEI Medical, Snowden & Pencer, Storz Laparoflator, Storz Endoflator, Wolf) and devices to maintain body temperature (Bair Hugger, fluid warmer, Blanketrol blankets). DESIGN: Prospective, nonrandomized study (Canadian Task Force classification II-1). SETTING: Community hospital in rural Alabama. PATIENTS: Sixty-two consecutive patients (53 women, 9 men; average age 56.8 yrs, range 21-94 yrs). INTERVENTIONS: Patients underwent standard laparoscopic and pelviscopic procedures during which intraoperative temperature changes in the insufflation system, abdomen, and rectum were measured. MEASUREMENTS AND MAIN RESULTS: Carbon dioxide was at room temperature in the insufflation hose ( approximately 23 degrees C). During insufflation, intraabdominal gas temperature decreased to as much as 27.7 degrees C (average 32.7 degrees C) depending on length of operation (23 min-5 hrs 8 min), amount of gas used (12.8-801 L), gas flow (up to 20 L/min), and leakage rate. Preoperative and postoperative temperature comparisons showed no decline in rectal temperature (average +0.18 degrees C) because warming equipment was sufficient. CONCLUSION: The decrease in intraoperative intraabdominal gas temperature is remarkable and can potentially harm the patient. It can be limited by restricting gas flow and leakage. In operations longer than 1 hour, substantial core body temperature drop should be prevented with appropriate heating and hydration devices. An insufflator with internal gas heating (Snowden & Pencer) had no significant clinical effect. (J Am Assoc Gynecol Laparosc 6(3):289-295, 1999)     

Adhesion formation and interanimal variability in a laparoscopic mouse model varies with strains

Adhesion formation after laparoscopic surgery was evaluated in mice of different strains. More adhesions were observed in Swiss, NMRI, and BALB/c mice, with less interanimal variability in BALB/c mice. These data point to genetics effects on adhesion formation, which open new insights in its pathogenesis and indicate the importance of a careful strain selection for animal studies.     

The hypogonadal (hpg) mouse as a model to investigate the estrogenic regulation of spermatogenesis

The hypogonadal (hpg) mouse is an excellent animal model in which to investigate the mechanism of action of estrogens on spermatogenesis because it has arrested reproductive development without the need for surgical, endocrine, pharmacological or immunological intervention. Hpg mice are hypogonadotrophic and fail to show normal postnatal testicular development due to the congenital inability to synthesize gonadotropin-releasing hormone in the hypothalamus. The hpg testis remains responsive to gonadotropins and androgens in that fertility can be induced by treatment with these hormones. Surprisingly, chronic treatment with low concentrations of estradiol alone induces qualitatively normal spermatogenesis. The induction of testicular development by estradiol in hpg mice is accompanied by a paradoxical increase in FSH production. The actions of estradiol in hpg mice appear to be via genomic estrogen receptors, as concurrent treatment with estrogen-receptor antagonist ICI182,780 completely blocks these pituitary and testis responses. Concurrent treatment with the androgen receptor antagonist bicalutamide does not affect the estradiol-induced increase in pituitary FSH content, but markedly attenuates the estradiol-induced increase in testicular weight. Western blot analyses and immunohistochemistry provide evidence for estrogen-receptor alpha and beta expression in both pituitary gland and testis of the hpg mouse. Estradiol may therefore exert direct actions within the testes and/or indirect neuroendocrine actions via the release of FSH or other hormones from the pituitary gland, but its actions are dependent upon the availability of low levels of androgen within the testis.     

Comparison of hysterosalpingographic and laparoscopic findings in tubal factor of sterility (author's transl)

Hysterosalpingographic and laparoscopic findings in 116 sterile women with the ovulatory cycle and the fertile spermiogram of their husbands were compared. Laparoscopy was performed in 65 patients in whom hysterosalpingography (HSG) revealed the occlusion of one or both tubes localized at the abdominal orifice, then in 23 women with unobstructed tubes and pertubal adhesions, and in 28 women in whom HSG findings were normal and who did not conceive at least 6 months after HSG. In 69% of cases the results of both methods were similar, whereas in 31% of cases laparoscopic findings, 18 laparoscopic findings showed significant by hysterosalpingography. Out of 28 normal HSG findings, 18 laparoscopic findings showed significant pathologic tubal changes. In unilateral occlusions HSG revealed peritubal adhesions in unobstructed tubes in 4 cases and laparoscopy in 18 out of 24 cases along with the agglutination of the fimbria and periovarian adhesions. In the whole group of the women examined, HSG revealed periadnexal adhesions in 39 (33%) and laparoscopy in 69 cases (59%).