A comparative study of angiogenic and cytokine responses after laparoscopic cholecystectomy performed with standard- and low-pressure pneumoperitoneum

Background  Surgical procedures enhance production of pro- and anti-inflammatory cytokines and angiogenic factors that play a pivotal role in the immunological response to surgical trauma and take part in the pathogenesis of tumor growth and adhesions formation. The purpose of the study was to access the influence of low-pressure CO₂ pneumoperitoneum on the inflammatory and angiogenic responses during the postoperative period after laparoscopy. Methods  The study group consisted of 40 patients, operated on due to cholelithiasis using standard-pressure (n = 20) and low-pressure (n = 20) CO₂ pneumoperitoneum. Serum concentration of interleukin (IL)-6, IL-8, IL-10, vascular endothelial growth factor (VEGF)-A, and endostatin were measured before and at 6, 24, and 48 h after surgery with commercially available enzyme-linked immunosorbent assay (ELISA). Results  Concentrations of IL-6 increased significantly after the operations in both groups. No differences were observed between the groups in regards to IL-6, IL-8, and IL-10 levels. Concentrations of VEGF-A measured at 6 and 48 h were significantly lower in patients who underwent laparoscopies performed with low-pressure pneumoperitoneum. No significant variations were observed in endostatin serum concentration. Concentrations of the studied parameters were not influenced by duration of surgery or by age, gender, or body mass index (BMI) of the patients. Conclusions  The results obtained in our study do not show any significant differences between studied operative procedures with regards to systemic inflammatory response. Changes in the concentrations of VEGF-A and endostatin observed in the studied population may suggest this technique is more favorable with regards to angiogenesis process intensity, along with all its consequences and implications.     

Application of a vibration measuring technique to evaluate the dynamic stiffness of porcine periodontal ligament.

The performance of a tooth replacement by using a dental implant relies on the mechanical and biological capability of the anatomical substitute to restore lost physiological functions. The design of an implant device able to properly replace the physiological tooth requires the study of the load transfer mechanism at the implant-bone interface and the understanding of the relevance of the periodontal ligament (PDL) in this mechanism. The PDL is a connective soft tissue that provides the fixation of the tooth in its bone-socket and the attenuation of occlusal loads. It also provides the ground cells that are involved in the remodelling process, induced by a change in the stress-strain pattern of the alveolar bone and also in the cementum of the tooth root. The purpose of this study was to determine the PDL effects on the dynamic load transfer mechanism, from the tooth to the alveolar bone, evaluating the equivalent dynamic stiffness of the ligament structure. A porcine fresh mandible with a tooth was used within the study, applying an experimental procedure to identify the dynamic transmissibility of the entire system. The transmissibility function provided information about the stiffness and damping of the PDL, information that can assist the design of an improved dental implant system.     

Determinants of left ventricular systolic function recovery after an acute coronary syndrome.

INTRODUCTION: Ischemic heart disease is a major cause of heart failure in western societies. However, the factors that may influence left ventricular function (LVF) recovery after an acute coronary syndrome (ACS) are still unclear. OBJECTIVE: To identify variables that may influence LVF evolution one year after ACS. METHODS: 104 patients hospitalized with ACS between 7/1/2001 and 12/31/2002 and with systolic dysfunction--defined as an echocardiographic ejection fraction (EF) < or = 45%--were randomly allocated to a planned coronary follow-up program (FUP) or a general cardiology clinic (GC); patients from both groups were also randomly referred to a structured cardiac rehabilitation program (CRP). EF was re-assessed at one year. We compared differences between patients who recovered left ventricular function (EF > 45%; group 1) and those who did not (group 2). RESULTS: One year after discharge, 44.2% of the patients had recovered function. There were no significant differences between the groups in gender (77.7 vs. 76.5% male), age (56 vs. 59 years), hypertension, diabetes, dyslipidemia, smoking habits or family history. A previous history of cardiovascular events was more frequent in group 2 (11.1% vs. 35.3%, p = 0.03). Cardiac catheterization was performed before discharge in 88.8% and 88.2% in groups 1 and 2 respectively (p = NS); no differences were found in coronary anatomy between the two groups. Angioplasty was performed in 54.2% in group 1 and 50% in group 2 (p = NS). There were no differences in the use of angiotensin-converting enzyme inhibitors (83.3% vs. 87.5%), beta-blockers (87.5% vs. 87.5%), nitrates (37.5% vs. 33.3%), aspirin (95.8% vs. 95.8%), statins (79.1% vs. 75%) or diuretics (20.8% vs. 45.8%). There was no significant difference in LVF recovery between patients randomized to FUP or GC (38.5% vs. 54.5%). 87.5% of patients who completed the CRP had normal EF at one year compared to 32.7% of patients not referred to the program (p = 0.009). Although EF improved in both groups, this improvement was greater in patients who completed a CRP (EF 8% vs. 5%, p = 0.003). CONCLUSION: A previous cardiovascular event and completion of a CRP were the only variables that influenced LVF recovery. Thus, enrollment in a CRP, in addition to standard therapy, could be an important therapeutic measure in patients with systolic dysfunction after ACS; our data suggest that these programs should be more widely used.     

Evidence of lowest brain penetration of an antiemetic drug, metopimazine, compared to domperidone, metoclopramide and chlorpromazine, using an in vitro model of the blood-brain barrier.

PURPOSE: The objective of the current study was to determine the ability of some antiemetic compounds to cross the blood-brain barrier (BBB) and thereby to determine possible side effects of compounds for the central nervous system (CNS). METHODS: We compared the brain penetration of some antiemetic compounds using an in vitro BBB model consisting in brain capillary endothelial cells co-cultured with primary rat glial cells. RESULTS: This study clearly demonstrated that the metopimazine metabolite, metopimazine acid, has a very low brain penetration, lower than metopimazine and even less than the other antiemetic compounds tested in this study. CONCLUSIONS: The poor brain penetration of metopimazine acid, metopimazine biodisponible form, seems very likely related to the clinically observed difference in therapeutic and safety profile.     

Novel azapeptide inhibitors of cathepsins B and K. Structural background to increased specificity for cathepsin B

Abstract: We have designed and synthesized a new series of azapeptides which act as potential inhibitors of cathepsin B and/or cathepsin K. Their structures are based upon the inhibitory sites of natural cysteine protease inhibitors, cystatins. For the synthesized azapeptides, the equilibrium constants for dissociation of inhibitor–enzyme complex, K_i, were determined. Comparison of these values indicated that all of the azainhibitors act much stronger toward cathepsin B. Z‐Arg‐Leu‐His‐Agly‐Ile‐Val‐OMe ( 7 ) proved to be approximately 500 times more potent for cathepsin B than for cathepsin K. To be able to explain the obtained experimental values we used the molecular dynamics procedures to analyze the interactions between cathepsin B and compound 7 . We also determined the structure of the most potent and selective cathepsin B azainhibitor by means of NMR studies and theoretical calculations. In this report, we describe SAR studies of azapeptide inhibitors indicating the influence of the conformational flexibility of the examined compounds on inhibition of cathepsins B and K.