COVID-19 lockdown, personal protective equipment, hyper-hygiene and allergy.

Summary: At the beginning of SARS-CoV 2 pandemic, in the absence of "targeted" therapies, the national health authorities have introduced some measures aimed at reducing the spread of infection in the community (lockdown, social distancing, personal protective equipment (PPE), personal hygiene and disinfection of living environments). All the containment measures have led to both positive and negative effects in patients with allergic diseases. We believe that further studies should be undertaken to investigate the possible correlations between SARS-CoV-2 infection and allergy, from a broader perspective. In particular, the risk factors for the development of undesirable effects should be investigated, especially in healthcare professionals forced to use PPE and sanitizing agents for a long time. However, since the COVID-19 pandemic probably will not be short-lived, the use of such protective aids will necessarily be widespread even in the general population. Therefore, further studies on the materials used for the production of PPE and sanitizing agents would be necessary to reduce their sensitizing and, in some cases, toxic potential.

Evaluation of endocrine therapy and patients preferences in early breast cancer: results of Elena study.

PURPOSE: The development of the adjuvant therapy requires that clinicians and patients should discuss the magnitude of benefit of treatment for individual patient, estimating the pros and cons and the personal preferences. The aim of the present study was to determine the preferences of women treated with adjuvant hormonal therapy (HT) for breast cancer. METHODS: The analyses were conducted into three different groups of early breast cancer patients to evaluate the survival benefit needed to make treatment worthwhile before starting HT (A), after a few months from the beginning (B) and after several years of HT (C). The questionnaires, showing hypothetical scenarios based on potential survival times and rates without HT, were used to determine the lowest gains women judged necessary to make the treatment worthwhile. RESULTS: A total of 452 patients were included in the study: 149 in group A, 150 in group B and 153 in group C. In group C, 65% of patients were receiving HT with aromatase inhibitors (with or without a LHRH analogue). In the groups A, B, C 8%, 20% and 26%, respectively, received adjuvant chemotherapy. Overall, 355 women (79%) had children. The responses were quite similar between the three groups. A median gain of 10 years was judged necessary to make adjuvant HT worthwhile based on the hypothetical scenario of untreated mean survival time of 5 and 15 years. Median gain of 20% more women surviving was judged necessary to make adjuvant HT worthwhile based on an untreated 5-year survival rate expectation of 60%. Cognitive dysfunction was considered the side effect least compatible with the continuation of treatment in all three groups. CONCLUSIONS: This is a large study of patient preferences on HT. Compared with other studies with similar design, the patients included in the present study required larger benefits to make adjuvant therapy worthwhile.

Physiological, biochemical and molecular responses to water stress and rehydration in Mediterranean adapted tomato landraces.

Mediterranean tomato landraces adapted to arid environments represent an option to counteract drought, and to address the complexity of responses to water deficit and recovery, which is a crucial component of plant adaptation mechanisms. We investigated physiological, biochemical and molecular responses of two Mediterranean tomato landraces, 'Locale di Salina' (Lc) and 'Pizzutello di Sciacca' (Pz) under two dehydration periods and intermediate rehydration in greenhouse pot experiments. Relationship between CO2 assimilation (A) and stomatal conductance under severe water stress (gs  < 0.05 mol·m-2 ·s-1 ) indicated the occurrence of stomatal and non-stomatal limitations of photosynthesis. Gas exchange promptly recovered within 2-3 days of rehydration. ABA and gs showed a strict exponential relationship. Both leaf ABA and proline peaked under severe water stress. Lc showed higher accumulation of ABA and higher induction of the expression of both NCED and P5CS genes than Pz. Poly(ADP-ribose) polymerase increased during imposition of stress, mainly in Lc, and decreased under severe water stress. The two landraces hardly differed in their physiological performance. Under severe water stress, gs showed low sensitivity to ABA, which instead controlled stomatal closure under moderate water stress (gs  > 0.15 mol·m-2 ·s-1 ). The prompt recovery after rehydration of both landraces confirmed their drought-tolerant behaviour. Differences between the two landraces were instead observed at biochemical and molecular levels.

Carbon dioxide pneumoperitoneum prevents mortality from sepsis.

BACKGROUND: Carbon dioxide (CO2) pneumoperitoneum has been shown to attenuate the inflammatory response after laparoscopy. This study tested the hypothesis that abdominal insufflation with CO2 improves survival in an animal model of sepsis and investigated the associated mechanism. METHODS: The effect of CO2, helium, and air pneumoperitoneum on mortality was studied by inducing sepsis in 143 rats via intravenous injection of lipopolysaccharide (LPS). To test the protective effect of CO2 in the setting of a laparotomy, an additional 65 animals were subjected to CO2 pneumoperitoneum, helium pneumoperitoneum, or the control condition after laparotomy and intraperitoneal LPS injection. The mechanism of CO2 protection was investigated in another 84 animals. Statistical significance was determined via Kaplan-Meier analysis for survival and analysis of variance (ANOVA) for serum cytokines. RESULTS: Among rats with LPS-induced sepsis, CO2 pneumoperitoneum increased survival to 78%, as compared with using helium pneumoperitoneum (52%; p < 0.05), air pneumoperitoneum (55%; p = 0.09), anesthesia control (50%; p < 0.05), and LPS-only control (42%; p < 0.01). Carbon dioxide insufflation also significantly increased survival over the control condition (85% vs 25%; p < 0.05) among laparotomized septic animals, whereas helium insufflation did not (65% survival). Carbon dioxide insufflation increased plasma interleukin-10 (IL-10) levels by 35% compared with helium pneumoperitoneum (p < 0.05), and by 34% compared with anesthesia control (p < 0.05) 90 min after LPS stimulation. Carbon dioxide pneumoperitoneum resulted in a threefold reduction in tumor necrosis factor-alpha (TNF-alpha) compared with helium pneumoperitoneum (p < 0.05), and a sixfold reduction with anesthesia control (p < 0.001). CONCLUSION: Abdominal insufflation with CO2, but not helium or air, significantly reduces mortality among animals with LPS-induced sepsis. Furthermore, CO2 pneumoperitoneum rescues animals from abdominal sepsis after a laparotomy. Because IL-10 is known to downregulate TNF-alpha, the increase in IL-10 and the decrease in TNF-alpha found among the CO2-insufflated animals in our study provide evidence for a mechanism whereby CO2 pneumoperitoneum reduces mortality via IL-10-mediated downregulation of TNF-alpha.

Laparoscopic surgery and the parasympathetic nervous system.

BACKGROUND: Laparoscopic surgery preserves the immune system and has anti-inflammatory properties. CO2 pneumoperitoneum attenuates lipopolysaccharide (LPS)-induced cytokine production and increases survival. We tested the hypothesis that CO2 pneumoperitoneum mediates its immunomodulatory properties via stimulation of the cholinergic pathway. METHODS: In the first experiment, rats (n = 68) received atropine 1 mg/kg or saline injection 10 min prior to LPS injection and were randomization into four 30-min treatment subgroups: LPS only control, anesthesia control, CO2 pneumoperitoneum, and helium pneumoperitoneum. In a second experiment, rats (n = 40) received atropine 2 mg/kg or saline 10 min prior to randomization into the same four subgroups described previously. In a third experiment, rats (n = 96) received atropine 2 mg/kg or saline 10 min prior to randomization into eight 30-min treatment subgroups followed by LPS injection: LPS only control; anesthesia control; and CO2 or helium pneumoperitoneum at 4, 8, and 12 mmHg. In a fourth experiment, rats (n = 58) were subjected to bilateral subdiaphragmatic truncal vagotomy or sham operation. Two weeks postoperatively, animals were randomized into four 30-min treatment subgroups followed by LPS injection: LPS only control, anesthesia control, CO2 pneumoperitoneum, and helium pneumoperitoneum. Blood samples were collected from all animals 1.5 h after LPS injection, and cytokine levels were determined by enzyme-linked immunosorbent assay. RESULTS: Serum tumor necrosis factor-alpha (TNF-alpha) levels were consistently suppressed among the saline-CO2 pneumoperitoneum groups compared to saline-LPS only control groups (p < 0.05 for all four experiments). All chemically vagotomized animals had significantly reduced TNF-alpha levels compared to their saline-treated counterparts (p < 0.05 for all), except among the CO2 pneumoperitoneum-treated animals. Increasing insufflation pressure with helium eliminated differences (p < 0.05) in TNF-alpha production between saline- and atropine-treated groups but had no effect among CO2 pneumoperitoneum-treated animals. Finally, vagotomy (whether chemical or surgical) independently decreased LPS-stimulated TNF-alpha production in all four experiments. CONCLUSION: CO2 pneumoperitoneum modulates the immune system independent of the vagus nerve and the cholinergic pathway.

Mammalian liver contains an activity which mimics bacterial chloramphenicol acetyltransferase.

Rat liver extracts contain an activity which mimics Escherichia coli chloramphenicol acetyltransferase (CAT); the latter is commonly used to report transcriptional activation of chimeric genes transfected into cultured cells. Although the activities are indistinguishable by the standard thin-layer chromatography assay, alternate methods can discriminate between them. The rat CAT-like activity appears to be an integral membrane protein. It was observed in the microsomal fraction of both liver and kidney. Similarly CAT-like activities were detected in mouse, rabbit and pig liver. In addition, liver homogenates which contain the CAT-like activity also contain a heat-labile inhibitor of (authentic) bacterial CAT.

ADP-ribosylation reactions in Sulfolobus solfataricus, a thermoacidophilic archaeon.

An ADP-ribosylating system was detected in a crude homogenate from Sulfolobus solfataricus, a thermophilic archaeon, optimally growing at 87 degrees C. The archaeal ADP-ribosylation reaction was time-, temperature- and NAD-dependent. It proved to be highly thermostable, with about 30% decrease of 14C incorporation from [14C]NAD on incubation at 80 degrees C for up to 24 h. The main reaction product was found to be mono-ADP-ribose. Testing both [adenine-14C(U)]NAD and [adenine-14C(U)]ADPR as substrates, it was found that acceptor proteins were modified by ADP-ribose both enzymatically, via ADP-ribosylating enzymes, and via chemical attachment of free ADP-ribose, likely produced by NAD glycohydrolase activity. The synthesis of ADP-ribose-protein complexes was shown to involve mainly acceptors with molecular masses in the 40-100 kDa range, as determined by electrophoresis on polyacrylamide gel in the presence of sodium dodecyl sulphate.

The role of the spleen in laparoscopy-associated inflammatory response.

BACKGROUND: Carbon dioxide (CO(2)) pneumoperitoneum alters the inflammatory response in animal models of sepsis. The spleen is a key organ in inflammation and its removal was predicted to modify this effect. METHODS: The acute phase inflammatory response to lipopolysaccharide (LPS) challenge in male rats was examined for the effects of splenectomy (spx) and the technique of removal (open or laparpscopic). A series of experiments compared LPS-only controls with LPS injection 2 or 9 days following open spx, lap CO2 spx, open sham, or lap CO2 sham. The method of splenectomy was studied by randomization to control, open spx, lap CO2 spx, lap helium (He) spx, or lap air spx with LPS challenge on postoperative day 2. Serum levels of tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (INF-gamma) and, interleutin (IL) 10 were collected at multiple time points, assayed by commercial enzyme-linked immunosorbent assay, analyzed by analysis of variance. RESULTS: Levels of TNF-alpha at 1.5 were significantly lower following open sham than following lap sham (p < 0.05). Splenectomy drastically reduced INF-gamma and TNF-alpha levels compared to controls (p < 0.05) on postoperative day 2. No method of spx preserved TNF-alpha or INF-gamma responses. Recovery of TNF-alpha response on day 9 was delayed in the spx groups. CONCLUSIONS: Splenectomy dramatically reduces TNF-alpha and INF-gamma responses to LPS challenge, although by different mechanisms. Pneumoperitoneum-mediated modulation of the septic inflammatory response is partially dependent on the spleen.

Identification of glycoproteins that are receptors for peanut agglutinin on immature (cortical) mouse thymocytes.

Binding of peanut agglutinin is being widely used as a marker for immature mouse thymocytes and for the separation of these cells from the mature thymocytes. Two cell surface glycoproteins that bind peanut agglutinin were detected on unfractionated as well as immature thymocytes by lectin overlay and affinity chromatography: one of Mr between 170 000 and 180 000, and the other, a minor component, of Mr 110000, both of which are partially sialylated. No receptors for peanut agglutinin were detected on the mature cells, whereas desialylation experiments revealed the presence of a glycoprotein of Mr 110000. These findings were corroborated by electrophoretic analysis of cell surface glycoproteins of the isolated thymocyte subpopulations labeled in their carbohydrate moieties.

A murine model for evaluating metastatic potential: characterization of a 90-110-kDa metastasis-binding protein.

Reliable discriminatory tests to predict metastatic disease would clearly facilitate the management of cancer in the elderly. We have recently identified a 90-110-kilodalton (kDa) cell surface glycoprotein that is differentially expressed in benign and malignant murine adrenal carcinoma cells. In view of the proteins highly glycosylated nature, we have tested its ability to bind to a panel of agarose-bound lectins. Wheat germ agglutinin (WGA), a lectin specific for terminal sialic acid and N-acetylglucosamine (G1cNAc), had a strong affinity for the metastasis-related protein but failed to detect such a glycoprotein in nonmetastatic cells. Treatment of cells with sialidase to remove terminal sialic acids did not affect the affinity of the protein for the lectin, indicating the presence of terminal G1cNAc. We show by in situ that this metastatic binding protein (MBP) is regionally concentrated on the surface of invasive cells but absent in cells unable to invade. We postulate that MBP plays an active role in cell migration through interactions with beta-1,4 galactosytransferase and basement membrane glycoproteines.

Increase in beta-galactosidase activity in a non-isothermal bioreactor utilizing immobilized cells of Kluyveromyces fragilis: fundamentals and applications.

The beta-galactosidase activity of Kluyveromyces fragilis cells immobilized in a kappa carrageenan gel was studied in a bioreactor functioning under isothermal and non-isothermal conditions. We observed an increase in enzyme activity which was found to be proportional to the intensity of the temperature gradient applied across the biocatalytic membrane, as well as to the average temperature of the bioreactor. The efficiency of such a non-isothermal bioreactor was calculated with respect to the yield of a bioreactor working under comparable isothermal conditions and was evaluated in terms of reduction of processing times in industrial applications. The possibility that enzyme activity in living cells is affected by non-isothermal conditions naturally existing owing to metabolic heat production is also discussed.

Heat shock proteins: facts, thoughts, and dreams.

The most primitive mechanism of cellular protection involves the expression of a polypeptide family named heat shock or stress proteins (hsps). Some of these hsps are present in unstressed cells and play an important role in the folding and translocation of polypeptides across membranes. Thus, they have been termed molecular chaperones. Hsps are expressed in response to an array of stresses, including hyperthermia, oxygen radicals, heavy metals, ethanol, and amino acid analogues. In addition, the heat shock response is induced during clinically relevant situations such as ischemia/reperfusion and circulatory and hemorrhagic shock. All of the above stresses have in common that they disturb the tertiary structure of proteins and have adverse effects on cellular metabolism. Pretreatment of cells with a mild stress, sufficient to induce the expression of hsps, results in protection to subsequent insults. This phenomenon has been coined "stress tolerance" and is apparently caused by the resolubilization of proteins that were denatured during the stress. In addition, cellular structures (microfilaments and centrosomes) and processes (transcription, splicing, and translation) are stabilized or repaired during a second stress in stress tolerant cells and organisms. There is a great body of evidence indicating a direct role of hsps in the stabilization of these events. The intrinsic capacity of hsps to protect cells has potential relevance as a natural mechanism of organ protection during harmful environmental conditions and operative procedures, and in the combat against pathogens.

Expression of HSP70 is impaired at the transcriptional level in stressed murine neuroblastoma cells.

Although the expression of heat shock or stress proteins (hsps) is a well conserved response to stress, the accumulation of these proteins is different between various cell-types. Particularly, cells of neuronal origin show a reduced expression of Hsp70 after stress. The possible mechanism of this reduced Hsp70 expression was studied in thermally stressed murine neuroblastoma cells (N18). These cells showed no detectable levels of Hsp70 or Hsp70 mRNA after heat shock. Hsp70 transcription was not detectable after stress. However, heat shock transcription factor 1 (HSF1) is active in these cells under stress conditions. Cells transiently transfected with the chloramphenicol acetyltransferase (CAT) gene under control of the human heat shock promoter showed a stress-dependent expression of CAT, suggesting that the cells contain the factors necessary for the expression of Hsp70. Integration of the foreign human heat shock promoter into genomic DNA did not affect its transcriptional inducibility. These results suggest that the impairment of Hsp70 expression in N18 cells is due to the environment (chromatin structure, methylation pattern) of the Hsp70 locus.

Expression of the connexin 43 gene is increased in the kidneys and the lungs of rats injected with bacterial lipopolysaccharide.

At the molecular level, the inflammatory response is characterized by changes in gene expression of various organ systems. One gene by which expression has been observed to be altered in the liver during inflammation is connexin (Cx) 32. Cx genes encode the polypeptide subunits of the hemichannels that comprise gap junctions. In the present study, an increase in the expression of a different Cx gene, Cx43, was observed in the kidney and lung of rats injected with a sublethal dose (1 mg/kg) of bacterial lipolysaccharide (LPS). To elucidate the possible mechanism by which the Cx43 expression is increased during inflammation, the 5' flanking region of the gene was cloned and coupled to a reporter gene (human growth hormone). This construct was transfected into cells of renal origin (NRK), which express Cx43 constitutively. The Cx43 promoter activity was indeed found in the cloned region, which contained 725 base pairs upstream of the transcriptional initiation site of the Cx43 gene. The Cx43 promoter activity was found to be increased by incubation of the transfected cells with serum obtained from LPS-treated rats. Moreover, direct incubation of the transfected cells with LPS or interleukin 1beta, but not with other cytokines, was observed to increase the Cx43 promoter activity. These results suggest the expression of Cx43 after administration of LPS is part of the inflammatory response. Moreover, the expression of this gene seems to be mediated by proinflammatory mediators.

Interruption of hepatic gap junctional communication in the rat during inflammation induced by bacterial lipopolysaccharide.

Gap junctional cellular communication is important in the propagation of signals that coordinate hepatic metabolism. Hepatocytes express two different connexin (Cx) genes, Cx32 and Cx26, which encode for the subunit component of gap junction channels. Previous studies have shown that the expression of hepatic Cx32 is reduced during inflammatory conditions. The objective of this study was to evaluate whether this decrease in Cx32 expression results in a decrease in hepatic gap junctional communication. Transfer of the dye Lucifer Yellow between hepatocytes was measured after microinjection of single cells in an isolated perfused liver. Livers were harvested from rats subjected to an inflammatory condition induced by administration of bacterial lipopolysaccharide (LPS). A decrease in gap junctional cellular communication was observed within 6 h of the LPS treatment. This decrease in dye coupling was reversible, because gap junctional communication returned to control levels within 48 h of the LPS injection. The inhibition of hepatic gap junctional communication was associated with the disappearance of Cx32 and Cx26 from the hepatocyte plasma membrane as detected by indirect immunostaining. Cx32 mRNA levels were also reduced during inflammation as previously reported. However, Cx26 mRNA levels were unaffected or even transiently increased after the injection of LPS without significant increase in the polypeptide level. Thus, the down-regulation of Cx32 and Cx26 from the hepatocyte surface is apparently due to a rapid degradation of the polypeptide from the cell surface. We hypothesize that this loss of gap junctional cellular communication within the liver may contribute to the disordered hepatic metabolic that occurs during inflammatory states.

Reciprocal expression of phosphoenolpyruvate carboxykinase and acute phase genes during acute inflammation.

Part of the hepatic response to injury is mediated by the expression of a gene family known as acute phase genes. Expression of acute phase genes is induced by the presence of cytokines in the circulation such as tumor necrosis factor alpha, interferon gamma, and interleukins-1 and -6. Simultaneous with the transcription of acute phase genes, there is a decrease in the expression of other genes such as albumin. In the present study, we report the decrease in transcription of the gene coding for phosphoenolpyruvate carboxykinase (PEPCK), a key regulatory enzyme in the gluconeogenic pathway, in rat liver during an acute inflammatory state induced by bacterial endotoxin. Steady-state mRNA levels of PEPCK decrease 3 h after endotoxin injection, returning to 70% of normal levels after 24 h. This decrease in PEPCK mRNA levels was due to a decline in the rate of transcription of the gene, most likely mediated by an increase in the circulating levels of insulin. However, expression of the PEPCK gene was not induced by an increase in the cellular levels of cAMP during inflammation. Such a lack of response to cAMP may be due to the inactivation of, or decrease in, the levels of the transcriptional factor(s) responsible for PEPCK transcription.

Presence of the stress-inducible form of hsp-70 (hsp-72) in normal rat colon.

The expression of heat shock proteins (hsp) is probably one of the most primitive mechanisms of cellular protection from stress. Pathogens such as viruses and bacteria have recently been found to induce the heat shock gene expression. In the present study hsp-72, the stress-inducible form of hsp-70, was detected by Western blotting in samples from rat distal colon (DC), proximal colon (PC), and terminal ileum (TI), but was not found in proximal small bowel (PSB) or other organs (liver, kidney, spleen, heart, and brain) of unstressed animals. The signal intensity of hsp-72 in colon (DC > PC > TI > PSB) correlates qualitatively with the presence of normal gut microflora. hsp-72 was also observed in DC, to a lesser extent in PC, but not in TI or PSB of bacteria-free or antibiotic-treated rats. Inflammatory states induced by the intravenous administration of endotoxin (1 mg/kg), the subcutaneous injection of zymosan (1 g/kg) or by cecal ligation and puncture (sepsis) failed to increase the hsp-72 levels in rat colon or other organs. These results demonstrate that hsp-72 is expressed in normal rat colon. However, the induction of hsp-72 expression may not be due solely to the presence of resident bacteria in the gut, but instead, may be the result of a more complex process.

Genetic component in the inflammatory response induced by bacterial lipopolysaccharide.

Multiple organ dysfunction syndrome (MODS) appears to be the result of a complex program influenced by multiple factors, including environmental, physiological, and immunological conditions. Thus, an uncontrolled inflammatory response following a stochastic event, the initial injury, is believed to be the cause for the development of this syndrome. Several lines of evidence suggest that a genetic component could contribute to the regulation of the inflammatory response, as well, but no direct evidence demonstrates a heritable predisposition to MODS. In the present study, a genetic contribution was demonstrated for the inflammatory response induced by the administration of bacterial lipopolysaccharide (LPS) in different, genetically distinct strains of inbred mice. A survey of five inbred strains showed that mortality following administration of Escherichia coli LPS (20 mg/kg) was highest in C57BL/6J (B6) mice, while A/J mice were the most resistant. Accordingly, B6 and A/J mice were examined further for differences in the inflammatory response elicited by LPS. B6 mice showed higher levels of circulating interleukin-1beta and interleukin-6, as well as higher mRNA levels of hepatic beta-fibrinogen (an acute-phase gene) and metallothionein. Surprisingly, the circulating levels of tumor necrosis factor-alpha were significantly higher in A/J than in B6 mice after LPS administration. Since B6 and A/J mice were bred and raised in identical environments and received the same LPS challenge, the contrasting inflammatory response that was observed is largely attributable to genetic differences between these two strains. These data illustrate that the response to injury could be modulated by the genetic background of the individual. This information may be pertinent for the care of critically ill patients.

Progesterone bioconversion by microalgal cultures.

Ten different strains of unicellular microalgae have been used in the bioconversion of progesterone. Regio and stereoselective reduction and hydroxylation of the title compound were induced. A 9,10-seco derivative was obtained in high yield by using Scenedesmus quadricauda.

Carbon dioxide pneumoperitoneum alters acute-phase response induced by lipopolysaccharide.

BACKGROUND: As laparoscopic surgery continues to expand in scope, septic patients will be exposed to carbon dioxide (CO2) pneumoperitoneum in increasing numbers. The biologic advantages or disadvantages of laparoscopic surgery in the setting of sepsis/inflammation are not known. In a rat model, we investigated whether CO2 pneumoperitoneum alters the inflammatory response induced by bacterial lipopolysaccharide (LPS). METHODS: Male rats were injected via the penile vein with LPS (1 mg/kg). Five hours later, the animals (n = 5) were subjected to CO2 pneumoperitoneum (group I) for 1h; the animals of group II (n = 5) served as controls (no pneumoperitoneum). At 6 h, all animals were killed and the liver harvested for analysis of hepatic acute-phase gene expression. Total RNA was isolated and analyzed by Northern blot hybridization with probes for alpha-2 macroglobulin (A2M) and detected by autoradiography. The film in the linear range of exposure was quantitated using an imaging system. The signal intensity corresponding to A2M mRNA was normalized by the signal corresponding to 28S rRNA detected by staining with methylene blue. RESULTS: The mRNA levels in group II was 6.5 +/- 0.9 vs 2.8 +/- 0.4 in group I. As compared with rats that received LPS only, those that received a combination of LPS and CO2 showed a reduction in A2M mRNA levels (57.4%, p = 0.006). CONCLUSIONS: These data demonstrate that the presence of CO2 pneumoperitoneum reduces the inflammatory response established by LPS. This finding challenges the generally accepted notion that smaller incisions alone account for the observed benefits of laparoscopic surgery. It further suggests that CO2 pneumoperitoneum - aided laparoscopic surgery impedes the inflammatory response and may therefore offer specific benefits over conventional surgery.