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The degradation of thymic humoral factor-gamma2 (THF-gamma2), an immunoregulatory octapeptide important for T-lymphocyte regulation, by enzymes present in human plasma, was investigated. THF-gamma2 was metabolized through two steps that involved the detaching of N-terminal amino acid leucine followed by hydrolysis of the Lys(6)-Phe(7) bond. The THF-gamma2 cleavages were sensitive to aminopeptidase and metalloproteinase inhibitors. The degradation was completely blocked by amastatin and specific inhibitors of angiotensin converting enzyme (ACE). The cleavages occurred independently, with two different kinetics, faster for the N-terminal hydrolysis than for that of the Lys(6)-Phe(7) bond. Purified human plasma ACE was used to characterize the hydrolysis of Lys(6)-Phe(7) bond. The K(m) and K(cat) values for THF-gamma2 hydrolysis were 0.273 mM and 107 s(-1), respectively. The optimum of chloride concentration was 300 mM, while that of pH was 7.6. The presence of ACE in circulating mononuclear cells raises the possibility that it may play a role in modulating the THF-gamma2 activity.

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The aim of the present study was to purify and characterize angiotensin-converting enzyme (ACE) present in frog ovary (Rana esculenta). Detergent and trypsin-extracted enzymes were purified using a one-step process, consisting of affinity chromatography on lisinopril coupled to Sepharose 6B. The molecular mass was 150 kDa for both detergent-extracted and trypsin-extracted enzyme. The specific activity of detergent-extracted and trypsin-extracted ACE was 294 U mg(-1) and 326 U mg(-1) respectively. The optimum pH range was from 7-8.5 at 37 degrees C and the optimum temperature was 50 degrees C. Optimum chloride concentration was about 200 mM for synthetic substrate FAPGG (N-[3-(2-furyl)acryloyl] L-phenylalanyl glycyl glycine) and angiotensin I, and 10 mM for bradykinin. The Km and Kcat values for FAPGG were 0.608 +/- 0.07 mM and 249 sec(-1) respectively and I50 values for captopril and lisinopril, two specific ACE inhibitors, were 68 +/- 12.55 nM and 6.763 +/- 0.66 nM respectively. Frog ovary tissue from prereproductive period was incubated in vitro in the presence of frog ovary ACE (2.5 mU/ml), captopril (0.1 mM), and lisinopril (0.1 mM). Production of 17beta-estradiol, progesterone, and prostaglandins E2 and F2alpha was determined. The data showed a modulation of 17beta-estradiol, progesterone and prostaglandin E2 production by ovary ACE.

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Angiotensin converting enzyme (ACE) was demonstrated to modulate the production of 17beta-estradiol, progesterone and prostaglandin E2 (PGE2) in frog ovary of Rana esculenta. However, the activity was not mediated by angiotensin II (Ang II). In an attempt to identify the peptide involved in the pathway modulated by ACE, bradykinin, another physiological substrate of ACE, was chosen and incubated in the presence of the membrane suspension purified from the frog ovary homogenate. The hydrolytic products were analysed by reverse-phase high-pressure liquid chromatography (HPLC) analysis and the results showed that bradykinin was metabolized by membrane suspension. The presence of the protease inhibitors in the incubation mixture indicated ACE and neutral endopeptidase as being responsible for the bradykinin hydrolysis. Frog ovary was incubated in vitro in the presence of bradykinin (10 microM), bradykinin receptor antagonist NPC 567 (1 mg mL-1), bradykinin fragment (1-7) (10 microM), ACE (2.5 mU mL-1), captopril (0.1 mM) and lisinopril (0.1 mM). The results showed no modulating activity by bradykinin on ovarian 17beta-estradiol and PGE2 production, thus demonstrating that it was not involved in the ACE-modulated pathway.

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BACKGROUND: The aim of this study was to verify if variations of thyroid hormones related to circumstances of delivery and mode of maternal anaesthesia can contribute to neonatal neutrophil respiratory burst and natural killer cell activity. METHODS: We evaluated 10 infants born by vaginal delivery (group A), 10 infants born by caesarean section after epidural anaesthesia with lidocaine (group B) and 10 infants born by caesarean section after general anaesthesia with sevoflurane (group C). RESULTS: A significant reduction of neutrophil respiratory burst test was found in groups A and C compared with group B. Natural killer cell (NK) activity with an effector : target ratio of 30 : 1 (NK30) and 10 : 1 (NK10) was significantly higher in group A compared with the B and C groups. In addition, thyroid stimulating hormone (TSH) concentration was significantly reduced in group A compared with the B and C groups. A significant negative correlation was found between TSH and NK30 or NK10. CONCLUSIONS: Our results suggest that the mode of delivery and anaesthesia can significantly modify the endocrine-immune system in the newborn. Caesarean section delivery with regional anaesthesia seems to produce fewer modifications of neonatal immune function compared with general anaesthesia.

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A fluorescent analog of epidermal mitosis-inhibiting pentapeptide (pGlu-Glu-Asp-Ser-Gly) was synthesized by reacting tetramethylrhodamine isothiocyanate with ring-opened epidermal mitosis-inhibiting pentapeptide. The ring-opening reaction of the pyrrolidone moiety was performed with mild acidic hydrolysis and the product purified by reversed-phase high-performance liquid chromatography. Tetramethylrhodaminethiocarbamoyl-(Glu(1))-epidermal mitosis-inhibiting pentapeptide was purified by chromatography on Sephadex G-25 and reversed-phase high-performance liquid chromatography. After characterization by amino acid analysis, the analog was incubated in presence of A431 cell line to visualize the cellular localization of the epidermal mitosis-inhibiting pentapeptide. The data gave negative results.

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BACKGROUND: Analysis of haemodynamic problems during single-lung transplantation and of methodologies employed for their treatment. DESIGN OF THE STUDY: clinical retrospective study. SETTING: General University Hospital. PATIENTS: patients with irreversible lung disease, either parenchymal or vascular, undergoing single lung transplantation. INTERVENTIONS: recording of circulatory failure episodes and treatment with pharmacologic support or cardiopulmonary bypass. Modifications occurring during the study period with respect to drugs administered. Evaluation of the consequences of cardiopulmonary bypass on the postoperative outcome, namely on the duration of mechanical ventilation and length of stay in the intensive care unit. RESULTS: During the last 9 years 69 single-lung transplantations have been performed. In 50% of cases a pharmacologic support has been employed; the drug association dobutamine/nitroprusside has been gradually replaced by the association norepinephrine/nitric oxide for the treatment of right ventricular failure. Twenty patients required cardiopulmonary bypass and this caused a significant increase of the duration of mechanical ventilation and length of stay in the intensive care unit. CONCLUSIONS: Hemodynamic changes during lung transplantation are complex and often severe, leading to a clinical status of right ventricular failure, that sometime requires a mechanical circulatory support. The introduction of nitric oxide in clinical practice significantly contributed to the optimization of intraoperative cardiocirculatory profile of patients, leading to a reduction in the use of vasoactive drugs and cardiopulmonary bypass.

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RATIONALE AND OBJECTIVES: Neonatal jaundice is a frequent problem in neonatology and can be influenced by many factors. Our study arose from the clinical observation that among all newborns delivered by caesarean section in our center, some had a more intense physiological jaundice. We began by reviewing clinical anesthesiological case-sheets to ascertain whether this difference was linked to the use of different anesthesiologic strategies. We then performed a prospective study on healthy preterm and term newborns to verify this hypothesis. STUDY DESIGN: We retrospectively considered all healthy term newborns with weight > 2,400 g delivered by caesarean section from January 1998 to May 1999. In the prospective studies we included healthy term and preterm newborns consecutively delivered by caesarean section from May 1999 to December 1999. We excluded preterm newborns with gestational age < 31 weeks and with weight < 1,400 g. RESULTS: Both in retrospective and in prospective studies anesthetic agents employed were isoflurane (A), sevoflurane (B), or bupivacaine (C). The statistical comparison of the three groups in retrospective study confirmed the clinical observation: the total bilirubin levels were significantly higher in the isoflurane group than in the sevoflurane group (p = 0.0000) and bupivacaine group (p = 0.0002). Analysis of data from the prospective study on term newborns confirmed our previous results. In preterm infants total bilirubin is statistically higher in group A starting from 96 h postdelivery. CONCLUSIONS: It is likely that anesthetic technique can be included among factors with possible influence on neonatal jaundice.

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Human lactation is influenced by a variety of interrelated factors. The purpose of the study was to see whether the racial/ethnic factor is predictive of the onset of lactation and of the volume of breast milk. We planned a prospective study enrolling 269 women who were classified into four ethnic groups: Group 1 Arabs, Group 2 Africans, Group 3 Eastern Europeans, Group 4 Italians. Data regarding the women's habits, medical history and pregnancy were collected. After delivery we recorded the onset of lactogenesis and volume of milk output up until the fifth post-delivery day. A Cox model was fitted in order to assess the independent role that ethnicity has on the time to lactation; a general linear model was used to relate ethnicity to the overall amount of milk produced. Mean age was 27 years and was similar in all groups; half of the women were primiparae. All babies were exclusively breast-fed. Median time to lactation was 36 hours (20-36) and the median daily amount of milk produced was 173.5 ml (119-215). The earliest onset of lactation and the highest milk output was registered among Arab and Eastern European women. On Cox regression analysis ethnicity appeared to be an independent predictor of earlier lactogenesis: breast milk output occurred significantly earlier in the immigrant population than it did in the Italian population. No difference was observed among the immigrants. The multiple regression model showed that ethnicity independently predicts the overall amount of milk production: the Immigrant population produced a significantly higher milk output than the Italian population. No differences were observed within the immigrant groups. Ethnicity has been shown to be associated with the characteristics of breast-feeding. Further research is needed to understand the underlying mechanism.

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UNLABELLED: The study objective was to delineate the trend of case reports (the simplest of the descriptive forms of study) in the anesthesiological literature by analyzing the frequency of publication, and citation, and especially of the place of citation of a sample of published case reports. It is our opinion that case report in anesthesia is particularly suitable for this specialty rather than for others and is often the first signal of a complication, an adverse event, an anesthetic problem in rare disease and alerts other anesthesiologists to the possibility of unexpected events. METHODS: We analyzed the case reports published on an Anesthesiological journal placed in the middle in term of Impact Factor, from January 1980 to December 1997. Citations of each case report were obtained using computer searches of the Science Citation Index (SCI). For each of these case reports we collected in a custom-designed data base the following data: year of publication, number of authors, number of citations per year, place of citation, type of article quoting the case report, number of self-citations, year of first citation. MAIN RESULTS: We identified 637 case reports and 1946 citations. The number of case reports increased through the years up to a peak in 1994-95 and the same trend was observed for citations and self-citations, the number of authors per case report was < or = 4 in 90.4%; 74.2% of total case reports cited were first cited within two years of publication, while 34.7% were never cited. The type of article quoting the case reports has been, in the majority of cases, an original article. CONCLUSIONS: The analysed case reports and the number of citations can give us information about the importance of a clinical situation at a particular time.

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Clinical research can be influenced by many factors that are capable of invalidating results, and one of these factors is known as the Hawthorne effect: the mere awareness of being under observation can alter the way in which a person behaves. In experimental research this effect can be the undesired effect of the experiments themselves, and the stronger its presence, the greater it can influence the results. In anesthesia practice, owing to the particular emotional condition of a patient facing a surgical operation, the Hawthorne effect could be especially strong. The aim of our study was to show the impact that the knowledge of being included in a study has (Hawthorne effect), by comparing the postoperative changes in psychological well-being in two groups of patients undergoing knee arthroscopy and receiving different information about the study from the anesthetist during the preoperative interview. Other signs and symptoms such as postoperative knee pain, nausea, vomiting (the most feared occurrences), headache, return of spontaneous diuresis, analgesic request, anesthesia complications, as well as the intensity of anxiety were also assessed as secondary endpoints. Our results show that subjects who were aware that they were part of a study scored significantly better on postoperative measures of psychological well-being and postoperative knee pain, compared to subjects who were unaware. The size of the effect, as measured by the odds ratio, remains unchanged when controlling for potential confounding factors. The study has enabled us to demonstrate the presence of the Hawthorne effect in clinical research. Therefore, the Hawthorne effect should be acknowledged and accounted for in the design of a study and in the interpretation of results.

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The aim of this study was to evaluate the influence of the method of delivery, the level of cord blood lidocaine, and the cortisol concentration on the cord blood natural killer (NK) activity in the full-term healthy newborn. We studied healthy newborns delivered by elective cesarean section without labor under general anesthesia (n = 24), delivered by cesarean section under epidural anesthesia (n = 21), and delivered vaginally with uncomplicated labor (n = 19). The NK cell activity was significantly lower in newborns delivered by cesarean section under epidural anesthesia than it was in the general anesthesia group, while it was similar to the levels found in vaginally delivered newborns. The cortisol concentration was highest in the vaginal delivery group (589.2 +/- 200 mmol/l) and lowest in the general anesthesia group (199.2 +/- 81.9 mmol/l). The mean serum lidocaine concentration was 414.1 +/- 370 microgram/l in the epidural anesthesia group and undetectable in the other groups. In conclusion, our data suggest that the cord blood NK activity was significantly influenced by the method of delivery. This effect could be related to anesthetics given to the mother for general or epidural anesthesia or to the endocrine-metabolic variations observed after different degrees of delivery-related stress. The NK cells being a first-line defense mechanism against viral infections, the results of this study suggest an association with the occurrence of early perinatal infections, especially in preterm infants.

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The aim of the present research was to study the role of angiotensin-converting enzyme (ACE) and ANG II in amphibian (Rana esculenta) testicular steroidogenesis and prostaglandin production. Hormonal effects of ACE, ACE inhibitors, synthetic bullfrog ANG I, and [Val(5)]ANG II were determined in frog testis of prereproductive period. Production of 17beta-estradiol, progesterone, androgens, and PGE(2) and PGF(2alpha) was determined by incubating frog testes with ACE (2.5 mU/ml), captopril (0.1 mM), lisinopril (0.1 mM), [Val(5)]ANG II (1 microM), and synthetic bullfrog ANG I (1 microM). The analysis of the data showed an independent modulation of 17beta-estradiol and androgen production by ACE and ANG II. The ACE pathway caused a decrease of 17beta-estradiol production and an increase of androgen production in frog testes; on the other hand, the ANG II pathway increased 17beta-estradiol production and decreased androgen production. The determination of testicular aromatase activity showed a positive regulation by ANG II and a negative regulation by ACE. As for prostaglandin production, only ANG II influenced PGF(2alpha). These results suggest a new physiological role of ACE and ANG II in modulating steroidogenesis and prostaglandin production.

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BACKGROUND: Sevoflurane is a good halogen agent for bariatric surgery anesthesia because of its physical and chemical characteristics and its repartition coefficient (blood/gas = 0.65). METHOD: From November 1997 to April 1998, 98 bariatric surgery procedures with sevoflurane anesthesia were done: 17 lipectomies, 71 vertical gastroplasties, and 10 biliopancreatic diversions in 71 women and 27 men, average age 30.3+/-8.3 years, with body mass index 43.9+/-5.7. The average operating time was 50+/-15 minutes for vertical gastroplasty, 160+/-20 minutes for biliopancreatic diversion, and 80+/-12 minutes for lipectomy. The technique of anesthesia was as follows: preanesthesia with atropine sulfate 0.01 mg/kg (dosage refers to ideal weight), ranitidine 50 mg, fentanyl 0.1 mg, ketorolac 60 mg; induction with propofol 0.5-1 mg/kg, succinylcholine 1 mg/kg; orotracheal intubation; maintenance with O2-N2O 50%, sevoflurane 1% to 1.5%, actracurium 0.5 mg/kg (dosage refers to ideal weight); awakening and decurarization with atropine sulfate 1 mg and prostigmine 2 mg. RESULTS: This method permitted correct control of the anesthesia, a quick awakening with a low incidence of nausea and vomiting, a prompt regain of physical and psychological functioning, an early discharge from the hospital, and a larger turnover of patients with lower costs. CONCLUSION: Sevoflurane balanced anesthesia seems to be the best anesthesiologic method for bariatric surgery.

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This study was conducted to determine the presence of the angiotensin converting enzyme in commercial sera used in cell culture medium. The aim of the research was to bring the presence of proteinases (angiotensin converting enzyme) to cell culture users' knowledge and to give some data for solving problems about the development of peptides as useful drugs. The enzymes, purified from foetal bovine, adult bovine, foetal equine, adult equine, and human sera, showed molecular weights of about 170 kDa. Captopril and lisinopril inhibited enzyme activities at nanomolar concentrations. The enzymes were able to hydrolyze, with different efficiency, angiotensin I, bradykinin and epidermal mitosis inhibiting pentapeptide. The heat inactivation of commercial sera at 56 degrees C for 30 min showed a reduction of ACE activity of about 35-80%. Therefore, the presence of ACE activity in commercial sera can influence the activity of biological peptides tested on cell lines cultured "in vitro."

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