Factors associated with time to defecate and outcomes in critically ill patients: a prospective, multicentre, observational study

Delayed defecation is common in patients on intensive care. We aimed to determine factors associated with time to defecation after admission to intensive care and in turn its association with length of stay and mortality. We studied 396 adults admitted to one of five intensive care units in whom at least 2 days' invasive ventilation was anticipated during an expected stay of at least 3 days. The median (IQR [range]) time to defecate by the 336 out of 396 (84%) patients who did so before intensive care discharge was 6 (4-8 [1-18]) days. Defecation was independently associated with five factors, hazard ratio (95%CI), higher values indicating more rapid defecation: alcoholism, 1.32 (1.05-1.66), p = 0.02; laxatives before admission, 2.35 (1.79-3.07), p < 0.001; non-invasive ventilation, 0.54 (0.36-0.82), p = 0.004; duration of ventilation, 0.78 (0.74-0.82), p < 0.001; laxatives after admission, 1.67 (1.23-2.26), p < 0.001; and enteral nutrition within 48 h of admission, 1.43 (1.07-1.90), p = 0.01. Delayed defecation was associated with prolonged intensive care stay but not mortality.

Vertical and horizontal fall-off of black carbon and NO2 within urban blocks

While exposure to traffic pollutants significantly decreases with distance from the curb, very dense urban architectures hamper such dispersion. Moreover, the building height reduces significantly the dispersion of pollutants. We have investigated the horizontal variability of Black Carbon (BC) and the vertical variability of NO₂ and BC within the urban blocks. Increasing the distance from road BC concentrations decreased following an exponential curve reaching halving distances at 25 m (median), although with a wide variability among sites. Street canyons showed sharper fall-offs than open roads or roads next to a park. Urban background concentrations were achieved at 67 m distance on average, with higher distances found for more trafficked roads. Vertical fall-off of BC was less pronounced than the horizontal one since pollutants homogenize quickly vertically after rush traffic hours. Even shallower vertical fall-offs were found for NO₂. For both pollutants, background concentrations were never reached within the building height. A street canyon effect was also found exacerbating concentrations at the lowest floors of the leeward side of the road. These inputs can be useful for assessing population exposure, air quality policies, urban planning and for models validation.

A combined chemical/size fractionation approach to study winter/summer variations, ageing and source strength of atmospheric particles

We studied the size distribution of ions (Cl^-, NO₃^-, SO₄⁼, Na⁺, NH₄⁺, K⁺, Mg⁺⁺, Ca⁺⁺) and elements (As, Ba, Cd, Co, Cs, Cu, Fe, Li, Mn, Ni, Pb, Rb, Sb, Se, Sn, Sr, Ti, Tl, V, Zn) during the winter and summer seasons of seven consecutive years (2008-2014) in an area of the Po Valley (Northern Italy) characterised by industrial, agricultural and urban settings. The study included the collection and analysis of 41 series of size-segregated samples (MOUDI sampler, 10 stages, cut sizes from 0.18 to 18 μm). Ions were analysed by ion chromatography; elemental analysis was carried out by ICP-MS, by applying a chemical fractionation method able to increase the selectivity of PM source tracers. Our results indicate that important winter/summer variations occurred in both the concentration and size distribution of most PM components. These variations were explained in terms of variations in the strength of the prevailing sources of each component. The contribution of biomass burning for domestic heating was highlighted by the well-known tracer K⁺ but also by the soluble fraction of Rb, Cs and Li. Biomass burning contribution to atmospheric PM was mostly contained in the fine fraction, with a broad size-distribution from 0.18 to 1.8 μm. This source also appreciably increased the concentration of other elements in fine PM (As, Cd, Co, Mn, Pb, Sb, Sn). A few PM components (tracers of sea-spray, brake lining and some industries) did not show marked seasonal variations in concentration and size distribution. However, during winter, for brake lining and industry tracers we observed an upward shift in the dimension of fine particles and a downward shift in the dimension of coarse particles, due to the ageing of the air masses.

[Bilateral breast reduction and obesity: What is the ideal resection enabling significant improvement in back pain according to the body mass index?]

INTRODUCTION

Dorsal pain is the first symptoms about which patients with macromasty complain. Health insurance reimbursement takes place if the resection weight is at least 300grams per breast. However, this weight is not correlated with the body mass index (BMI). In this context, we sought to determine the ideal resection weight leading to significant BMI-based improvement.

MATERIALS AND METHODS

This is a multicentre prospective study of patients operated between November 2016 and July 2017. In the year following the surgical procedure, we studied overall improvement using the INDIC questionnaire. Any INDIC improvement of at least 50% was considered positive. These data were then compared to tissue resection weights and BMI. In order to refine our results, age, bra size, comorbidities and complications were also identified.

RESULTS

Forty-one patients were included in our study. Average age was 41.5±11.4years. Average BMI was 27.9±4.1kg/m². The bra cap chosen after the procedure were C. Average resection weight was 663±352g per breast. The preoperative and postoperative INDIC scores were 734.9±226.6 points and 225.3±319.1 points, respectively (P=0.001). Significant improvement was achieved at 12months in 71.8% of patients. A correlation of 38.7g/kg/m² was found between breast resection weight and BMI.

CONCLUSION

This study clarifies the correlation between the breast resection weight required to relieve optimal back pain and BMI. It defines three categories of patients: patients with standard weights (18<BMI<25), overweight (25<BMI<30) and obese (BMI>30). Overweight and obese patients require greater tissue excretion to be relieved optimally. These findings underline a need to adjust the health insurance threshold for these types of patients.

Ageing and obesity similarly impair antibody responses

Ageing is characterized by increased low-grade chronic inflammation, which is a significant risk factor for morbidity and mortality of elderly individuals. Similar to ageing, obesity is considered to be an inflammatory predisposition associated with chronic activation of immune cells and consequent local and systemic inflammation. Both ageing and obesity are characterized by reduced innate and adaptive immune responses. This review focuses on B cells, how they may contribute, at least locally, to low-grade chronic inflammation in ageing and obesity and on the mechanisms involved.

MULTILAYER GRAPHENE CHLORINE ISOBUTYL ISOPRENE RUBBER NANOCOMPOSITES: INFLUENCE OF THE MULTILAYER GRAPHENE CONCENTRATION ON PHYSICAL AND FLAME-RETARDANT PROPERTIES

In recent years, different nanoparticles have been proposed and successfully introduced as nanofillers in rubber nanocomposites. In this study, multilayer graphene (MLG) is proposed as a nanoparticle that functions efficiently at low concentrations. MLG consists of just 10 or so graphene sheets. Chlorine isobutyl isoprene rubber (CIIR)/MLG nanocomposites with different MLG loadings were prepared using an ultrasonically assisted solution mixing procedure followed by two-roll milling. The incorporation of MLG provides a clear improvement in the rheological, mechanical, curing, and gas barrier properties of the nanocomposites. Adding only 3 phr of MLG to CIIR increased the Young's modulus by more than two times and reduced the permeability of O2 and CO2 by 30%. Higher nanofiller concentrations yielded further improvement in the properties of the nanocomposites. Moreover, CIIR/MLG nanocomposites showed reduced flammability.

Comparison of acoustic and impedance methods with mask capnometry to assess respiration rate in obese patients recovering from general anaesthesia

Respiratory depression, a potentially serious complication after general anaesthesia, can be detected promptly by close monitoring of both oxygen saturation and respiratory rate. Obese patients have morphological changes that may impair the reliability of monitoring devices. In this study, respiration rate was simultaneously recorded every second for up to 60 min using a computer in 30 adult obese patients (body mass index ≥ 35 kg.m(-2)), by three methods: acoustic; thoracic impedance; and capnometry via a facemask (Capnomask, reference method). Of the 99,771 data triplets collected, only 85,520 (86%) were included; 12,021 (84%) were not studied due to failure of capnometry and 2240 (16%) due to failure of the acoustic method. Compared with capnometry, bias was similar using both the acoustic method and impedance (-0.3 bpm vs. -0.6 bpm, respectively, p = 0.09), but limits of agreement were narrower for the acoustic method (±3.5 bpm vs. ±5.3 bpm, respectively, p = 0.0008). The proportion of respiration rate values obtained with the acoustic method and impedance that differed by at least 10% or 20% for more than 15 s were 11% vs. 23% and 2% vs. 6%, respectively (p = 0.0009 for both comparisons). The acoustic sensor was well tolerated, while the facemask was pulled off on several occasions by four (13%) agitated patients. In obese patients requiring close monitoring of respiration rate, the acoustic method may be more precise than thoracic impedance and better tolerated than capnometry with a facemask.

Seasonal variations in the chemical composition of particulate matter: a case study in the Po Valley. Part II: concentration and solubility of micro- and trace-elements

Size distribution (fine and coarse fraction) and solubility distribution (extracted and residual fraction) of 20 elements (As, Ba, Be, Cd, Co, Cu, Fe, Li, Mn, Pb, Ni, Rb, S, Sb, Se, Sn, Sr, Ti, Tl, V) in atmospheric particulate matter (PM) were determined during a 5-year field study carried out in the Po Valley (peri-urban area of Ferrara, in Northern Italy). By studying the contribution of the two size fractions and the two solubility fractions to the atmospheric concentration of each element, it was possible to obtain interesting information about the variability of PM sources, to assess the role played by atmospheric stability in determining pollution episodes, and to obtain an estimate of the bio-accessible fraction. Atmospheric stability is confirmed to be one of the main causes of atmospheric pollution in this area and is to be responsible for the pronounced winter increase in both PM and elemental concentration. Long-range transport of natural and polluted air masses caused temporary increases in PM and elemental concentration, while local industrial emission seemed to play a secondary role. Regulated elements were well below their concentration limit, but many toxic elements were in the form of fine particles and soluble chemical species, more accessible to the environment, and the human body.

Tumor VEGF:VEGFR2 autocrine feed-forward loop triggers angiogenesis in lung cancer

The molecular mechanisms that control the balance between antiangiogenic and proangiogenic factors and initiate the angiogenic switch in tumors remain poorly defined. By combining chemical genetics with multimodal imaging, we have identified an autocrine feed-forward loop in tumor cells in which tumor-derived VEGF stimulates VEGF production via VEGFR2-dependent activation of mTOR, substantially amplifying the initial proangiogenic signal. Disruption of this feed-forward loop by chemical perturbation or knockdown of VEGFR2 in tumor cells dramatically inhibited production of VEGF in vitro and in vivo. This disruption was sufficient to prevent tumor growth in vivo. In patients with lung cancer, we found that this VEGF:VEGFR2 feed-forward loop was active, as the level of VEGF/VEGFR2 binding in tumor cells was highly correlated to tumor angiogenesis. We further demonstrated that inhibition of tumor cell VEGFR2 induces feedback activation of the IRS/MAPK signaling cascade. Most strikingly, combined pharmacological inhibition of VEGFR2 (ZD6474) and MEK (PD0325901) in tumor cells resulted in dramatic tumor shrinkage, whereas monotherapy only modestly slowed tumor growth. Thus, a tumor cell-autonomous VEGF:VEGFR2 feed-forward loop provides signal amplification required for the establishment of fully angiogenic tumors in lung cancer. Interrupting this feed-forward loop switches tumor cells from an angiogenic to a proliferative phenotype that sensitizes tumor cells to MAPK inhibition.

Accuracy of respiratory rate monitoring using a non-invasive acoustic method after general anaesthesia

BACKGROUND

Respiratory rate should be monitored continuously in the post-anaesthesia care unit (PACU) to avoid any delay in the detection of respiratory depression. Capnometry is the standard of care but in extubated patients requires a nasal cannula or a face mask that may be poorly tolerated or can be dislodged, leading to errors in data acquisition and false alarms. The value of a new non-invasive acoustic monitor in this setting has not been fully investigated.

METHODS

Adult patients admitted to the PACU after general anaesthesia were included. After tracheal extubation, an adhesive sensor with an integrated acoustic transducer (RRa™) was placed on the patient's throat and connected to its monitor while the patient breathed through a face mask with a carbon dioxide sampling port (Capnomask™) connected to a capnometer. Both the acoustic monitor and the capnometer were connected to a computer to record one pair of data per second for up to 60 min.

RESULTS

Fifty-two patients, mean (range) age 54 (22-84) yr and BMI 26 (19-39) kg m(-2), were studied. Compared with capnometry, the bias and limits of agreement of the acoustic method were 0 (-1.4-1.4) bpm. The acoustic sensor was well tolerated while the face mask was removed by eight patients, leading to study discontinuation in two patients.

CONCLUSIONS

In extubated patients, continuous assessment of respiration rate with an acoustic monitor correlated well with capnometry.

Accuracy of respiratory rate monitoring by capnometry using the Capnomask(R) in extubated patients receiving supplemental oxygen after surgery

BACKGROUND

Respiratory monitoring is standard after anaesthesia and surgery. Abnormal respiratory rate is a sensitive indicator of respiratory problems, even in patients receiving supplemental oxygen, but the best method for its continuous measurement in spontaneously breathing patients is unclear. This study compared respiratory rate assessment by capnometry using a new oxygen mask with a carbon dioxide sampling port (Capnomask(®)) and thoracic impedance pneumography with clinical measurement (used as a reference method) in extubated patients receiving supplemental oxygen.

METHODS

Adult males admitted to the post-anaesthesia care unit after general anaesthesia were studied. Immediately after extubation, a Capnomask(®) connected to a capnometer was positioned appropriately. Respiratory rate was measured by visual inspection of chest movement for 1 min, by capnometry, and thoracic impedance pneumography. One set of measurements was obtained for every patient receiving supplemental oxygen at different flow rates.

RESULTS

Twenty men, mean (inter-quartile range) age 54 (23-66) yr and BMI 25 (21-31) kg m(-2), were studied. Compared with visual inspection, the bias and limits of agreement were 0.0 (1.0 to -1.0) bpm for the Capnomask(®) and -2.2 (2.0 to -6.5) bpm for the impedance pneumography. The accuracy of respiratory rate assessment using Capnomask(®) was not influenced by the supplemental oxygen flow rate.

CONCLUSIONS

In extubated patients, continuous assessment of respiratory rate with the Capnomask(®) is more accurate than by thoracic impedance pneumography even when supplemental oxygen is delivered at a high flow rate.

Rotational positioning of the tibial tray in total knee arthroplasty: a CT evaluation

INTRODUCTION

Various surgical techniques have been described to set the rotational alignment of the tibial baseplate during total knee arthroplasty. The self-positioning method ("self-adjustment") aligns the tibial implant according to the rotational alignment of the femoral component which is used as a reference after performing repeated knee flexion/extension cycles. Postoperative computed tomography scanning produces accurate measurements of the tibial baseplate rotational alignment with respect to the femoral component.

HYPOTHESIS

The rotational positioning of the tibial baseplate matches the rotation of the femoral component with parallel alignment to the prosthetic posterior bicondylar axis.

PATIENTS AND METHODS

A 3-month follow-up CT scan was carried out after primary total knee arthroplasty implanted in osteoarthritic patients with a mean 7.8° varus deformity of the knee in 50 cases and a mean 8.7° valgus deformity of the knee in 44 cases. The NexGen LPS Flex (Zimmer) fixed-bearing knee prosthesis was used in all cases. An independant examiner (not part of the operating team) measured different variables: the angle between the anatomic transepicondylar axis and the posterior bicondylar axis of the femoral prosthesis (prosthetic posterior condylar angle), the angle between the posterior bicondylar axis and the posterior marginal axis of the tibial prosthesis, the angle between the posterior marginal axis of the tibial prosthesis and the posterior marginal axis of the tibial bone and finally the angle between the anatomic transepicondylar axis and the posterior marginal axis of the tibial prosthesis.

RESULTS

For the genu varum and genu valgum subgroups, the mean posterior condylar axis of the femoral prosthesis was 3.1° (SD: 1.91; extremes 0° to 17.5°) and 4.7° (SD: 2.7; extremes 0° to 11°) respectively. The tibial baseplate was placed in external rotation with respect to the femoral component: 0.7° (SD : 4.45; extremes -9.5° to 9.8°) and 0.9° (SD: 4.53; extremes -10.8° to 9.5°), but also to the native tibia: 6.1° (SD: 5.85; extremes -4.6° to 22.5°) and 12.5° (SD: 8.6; extremes -10° to 28.9°). The tibial component was placed in internal rotation relative to the anatomic transepicondylar axis: 1.9° (SD : 4.93; extremes -13.6° to 7°) and 3° (SD : 4.38; extremes -16.2° to 4.8°).

DISCUSSION

The tibial component is aligned parallel to the femoral component whatever the initial frontal deformity (P≅0.7). However, a difference was observed between the rotational alignment of the tibial baseplate and the native tibia depending on the initial deformity and could be attributed to the morphological variations of the bony tibial plateau in case of genu valgum.

CONCLUSION

The self-positioning method is a reproducible option when using this type of implant since it allows the tibial component to be positioned parallel to the posterior border of the femur.

Reliability of the HemoCue® hemoglobinometer in critically ill patients: a prospective observational study

BACKGROUND

The aim of the study was to assess the reliability of hemoglobin measurements made with HemoCue®, compared with those made with the reference method in critically ill patients.

METHODS

A prospective observational study was conducted in three adult surgical intensive care units of a university hospital. One hundred and ninety-eight consecutive patients were included, and a total of 1166 hemoglobin concentrations were measured using arterial blood samples in the laboratory (HbLAB) and at bedside (HbHC.art) with a portable hemoglobinometer (HemoCue® Hb201+). Simultaneously, a capillary measurement (HbHC.cap) was performed at bedside using the same device.

RESULTS

The mean difference (bias) between HbHC.cap and HbLAB was 0.2 g/dL (95%CI, 0.1;0.3), and limits of agreement were -1.3 g/dL (95%CI, -1.4;-1.2) to 1.7 g/dL (95%CI, 1.6;1.9). The discrepancies between HbHC.cap and HbLAB were greater than 1 g/dL in 30.8% of cases. The bias between HbHC.art and HbLAB was -0.1 g/dL (95% CI, -0.2;0.2), and limits of agreement were slightly better at -1.1 g/dL (95% CI, -1.2;-1.0) and 1.0 g/dL (95% CI, 0.9;1.1). The HemoCue®'s accuracy was not affected by the hospital unit, the puncture site (finger or ear), norepinephrine administration or by hemoglobin levels below 10 g/dL or 8 g/dL.

CONCLUSION

Capillary HemoCue® is not sufficiently accurate to make a therapeutic decision such as whether a blood transfusion should be performed. The method's performance was moderately improved by the use of arterial blood.

[Practice assessment of central venous lines care in surgical ICU of French university hospitals]

INTRODUCTION

Recommendations on insertion and maintenance of central venous catheters (CVC) in intensive care unit (ICU) patients were updated in 2002. The aim of this study was to estimate their knowledge and/or application by physicians in French university hospital ICUs.

METHODS

Two forms were sent to 124 professors of anaesthesia and intensive care encouraging them to participate to the survey. The first one was completed by the physician in charge of each unit and concerned the structure and activity of the unit in 2006. The second one was filled by each junior or senior physician working in the units and asked for experience, CVC insertion modalities and knowledge of CVC care protocols.

RESULTS

Forty-one (75 %) university hospitals with at least one adult surgical ICU took part to the study. A questionnaire was filled by 124 senior (75 % of the staff) and 53 junior (43 % of the staff) physicians inserting an average of 10 CVC per month (range, 1-35). A written protocol for CVC insertion was known by 127 (72 %) of them. CVC insertion was done while wearing sterile gown (97 %), cap (100 %) and surgical mask (100 %) and using large sterile drapes (96 %). The antiseptic solution used for cutaneous antisepsis was povidone iodine in aqueous (36 %) or alcoholic solution (40 %), or an alcoholic solution of chlorhexidine (24 %) applied one (9 %), two (64 %) or three (27 %) times before insertion. A 4-times disinfection sequence (washing, rinsing, drying and disinfection) was performed by 161 (91 %) physicians. Ultrasound-guided insertion was realized by only eight (5 %) operators. CVCs were made of polyurethane (84 %), usually multi-lumens (>96 %) and rarely tunnelised (14 %). Only two physicians (1 %) sometimes use catheters coated with antibiotics or antiseptics. The site for catheter insertion was mostly the sub-clavian (47 %) or internal jugular vein (34 %), and rarely the femoral vein (20 %). CVCs were secured with a thread (99 %) and covered with a semi-permeable dressing (76 %). Concerning CVCs maintenance, 91 % of physicians acknowledged the existence of a written protocol in the unit. Dressings were changed every day (10 %), every two days (49 %), every three days (29 %) or every four days or more (12 %) by using the same antiseptic solution and semi-permeable transparent dressing in 78 % of cases. Venous lines changes were done during dressing maintenance (48 %), every day in case of administration of lipids (32 %) or just after administration of blood products via the catheter (32 %). Routine change of CVC was rarely recommended (11 %).

CONCLUSION

The high number of answers allows setting of a precise state of CVCs insertion practices in adult surgical ICUs. Recommendations for central venous catheter insertion and maintenance are not still known and\or applied.

Gabapentin premedication: assessment of preoperative anxiolysis and postoperative patient satisfaction

BACKGROUND

Gabapentin reduces anxiety in psychiatric patients. In this prospective, randomized, double-blinded, placebo-controlled study, we investigated whether a single dose of gabapentin as a premedicant reduces preoperative anxiety, and improves patient satisfaction.

MATERIALS AND METHODS

After Institutional Review Board approval and written consent, 210 patients were randomly allocated into 3 groups of oral premedication: placebo, hydroxyzine 75 mg, or gabapentin 1200 mg. Anxiety level was assessed 3 times, using a 100-mm visual analogue scale: before premedication, in the preoperative holding area, and just before induction of general anaesthesia. In the postoperative period, patients were asked about their satisfaction with their premedicant. Data were presented as mean +/- SD. VAS scores were analyzed by repeated-measures analysis of variance followed by a Bonferroni test as appropriate. The chi-square test was used to analyze categorical data. All p values less than 0.05 was considered statistically significant.

RESULTS

Baseline anxiety was not statistically different among the 3 groups. Anxiety level in the gabapentin group was significantly lower in the holding area, and before induction of anaesthesia (20 mm +/- 21), than in the hydroxyzine group (33 mm +/- 26 ; p = 0.023) and in the placebo group (36 mm +/- 28; p = 0.004). Anxiety decreased significantly overtime only in the gabapentin group. The gabapentin and hydroxyzine groups had a higher proportion of "satisfied or extremely satisfied" patients (73% and 70% respectively) as compared to the placebo group (48%, p = 0.006).

CONCLUSION

A single dose of gabapentin has proven to be an effective premedication to reduce preoperative anxiety.

[Total spinal anesthesia after interscalenic plexus block]

The interscalenic block prolonged by a catheter allows an optimal analgesia for important surgery of the shoulder. Its realization is easy but exposes to potentially serious complications. We report a case of spinal anaesthesia due to the accidental catheterization of the medullar canal at the time of an interscalenic block. An examination by tomodensitometry showed images of myelography explained by the injection of non ionic contrast media agent in the catheter at the time of X-ray control. The regression of neurological signs was fast and without after-effect. This observation recalls that in spite of all the safety measures, the realization of locoregional anaesthesia can be burdened with accidents. The proscription of a major sedation and the use of short needles are elementary rules to realize the interscalenic block. The improvement of puncture techniques, ultra-sound location or use of stimulative catheters can decrease the risk of this kind of accident.

Interleukin-6 release in the hepatic blood outflow during normothermic liver ischaemia in humans

BACKGROUND

Liver surgery techniques have consistently improved and normothermic ischaemia of the liver is considered to be a safe procedure to reduce intraoperative haemorrhage. Hepatic failure, however, remains a significant complication. In liver ischaemia-reperfusion injury, cytokines play a key proinflammatory role. Cytokines may be part of the intercellular signalling that leads to recovery or to failure after major surgery. Moreover, they could be potential predictors of the outcome. Modulation of the pattern of cytokine response in the early postsurgery period could represent a new approach to minimise the impact of these procedures.

AIMS

The aim of our study was to analyse the cytokine pattern in the hepatic blood outflow in patients undergoing surgical intervention of partial liver resection with clamping of the hepatic pedicle and liver ischaemia, and to correlate the cytokine behaviour with clinical parameters.

PATIENTS

We studied eight patients (mean age 55 years) who underwent surgical intervention of liver resection during vascular exclusion of the hepatic pedicle. Patients were monitored for haemodynamic and haematological parameters during the pre-, infra- and postoperative period.

METHODS

IL-I alpha, IL-6, TNF-alpha and IFN-gamma were assayed from peripheral and central vein blood at different times. Blood samples for cytokine assays were also drawn from the supra-hepatic veins after clamping of the porta hepatis.

RESULTS

We found a significant increase of the IL-6 levels in the supra-hepatic samples during liver ischaemia, while the trend with IL-1alpha was less clear; IFN-gamma and TNF-alpha were undetectable with the methods used. IL-6 levels appeared to correlate positively with bilirubin and gamma-GT levels and negatively with the degree of acidosis.

CONCLUSIONS

Our study confirms that during surgical ischaemic stress there is an increase of IL-6 serum levels more relevant in supra-hepatic vein blood. Cytokines could contribute to modulate the inflammatory response to liver ischaemia.

Expression and DNA binding activity of the Ku heterodimer in bladder carcinoma

BACKGROUND

The Ku protein is a tightly associated heterodimer, comprised of 70-kilodalton (kD) and 86-kD subunits, that forms the DNA-dependent protein kinase (DNA-PK) complex together with the 470-kD DNA-PKcs catalytic subunit, and is involved mainly in DNA double-strand breaks (DSBs) repair. The objective of the current study was to investigate the expression and DNA-binding activity of the Ku protein in fresh tissues from patients with bladder carcinoma and to compare it with that in nontumor tissues obtained from the same organ. Moreover, the DNA-binding activity of Ku was assessed after exposure of the tumor cells to 1 or 2 grays (Gy) of X-rays. Furthermore, the level of phosphorylated Ku was analyzed in both the nuclear and cytoplasmic compartment of normal tissue after exposure to 2 Gy of X-rays.

METHODS

The expression and DNA-binding activity of Ku protein were assessed in tumor samples from patients who all were diagnosed with transitional cell carcinoma (TCC) of the bladder using Western blot analysis and the electrophoretic mobility shift assay, respectively.

RESULTS

Enhanced Ku activity and expression were found in tumor tissue compared with normal tissue for each patient. Moreover, variations in Ku activity were found in a dose-dependent manner after the tumor cells were exposed to 1 or 2 Gy of X-rays. A decrease in phosphorylated Ku in the cytoplasm and a parallel increase in the nucleus of normal tissue cells were observed after exposure to X-rays.

CONCLUSIONS

The results of the current study suggest a possible role of Ku in regulating the DNA-PK activity of DSBs repair in bladder tumors.

Expression and DNA binding activity of the Ku heterodimer in bladder carcinoma

BACKGROUND

The Ku protein is a tightly associated heterodimer, comprised of 70-kilodalton (kD) and 86-kD subunits, that forms the DNA-dependent protein kinase (DNA-PK) complex together with the 470-kD DNA-PKcs catalytic subunit, and is involved mainly in DNA double-strand breaks (DSBs) repair. The objective of the current study was to investigate the expression and DNA-binding activity of the Ku protein in fresh tissues from patients with bladder carcinoma and to compare it with that in nontumor tissues obtained from the same organ. Moreover, the DNA-binding activity of Ku was assessed after exposure of the tumor cells to 1 or 2 grays (Gy) of X-rays. Furthermore, the level of phosphorylated Ku was analyzed in both the nuclear and cytoplasmic compartment of normal tissue after exposure to 2 Gy of X-rays.

METHODS

The expression and DNA-binding activity of Ku protein were assessed in tumor samples from patients who all were diagnosed with transitional cell carcinoma (TCC) of the bladder using Western blot analysis and the electrophoretic mobility shift assay, respectively.

RESULTS

Enhanced Ku activity and expression were found in tumor tissue compared with normal tissue for each patient. Moreover, variations in Ku activity were found in a dose-dependent manner after the tumor cells were exposed to 1 or 2 Gy of X-rays. A decrease in phosphorylated Ku in the cytoplasm and a parallel increase in the nucleus of normal tissue cells were observed after exposure to X-rays.

CONCLUSIONS

The results of the current study suggest a possible role of Ku in regulating the DNA-PK activity of DSBs repair in bladder tumors.

Expression and DNA binding activity of the Ku heterodimer in bladder carcinoma

BACKGROUND

The Ku protein is a tightly associated heterodimer, comprised of 70-kilodalton (kD) and 86-kD subunits, that forms the DNA-dependent protein kinase (DNA-PK) complex together with the 470-kD DNA-PKcs catalytic subunit, and is involved mainly in DNA double-strand breaks (DSBs) repair. The objective of the current study was to investigate the expression and DNA-binding activity of the Ku protein in fresh tissues from patients with bladder carcinoma and to compare it with that in nontumor tissues obtained from the same organ. Moreover, the DNA-binding activity of Ku was assessed after exposure of the tumor cells to 1 or 2 grays (Gy) of X-rays. Furthermore, the level of phosphorylated Ku was analyzed in both the nuclear and cytoplasmic compartment of normal tissue after exposure to 2 Gy of X-rays.

METHODS

The expression and DNA-binding activity of Ku protein were assessed in tumor samples from patients who all were diagnosed with transitional cell carcinoma (TCC) of the bladder using Western blot analysis and the electrophoretic mobility shift assay, respectively.

RESULTS

Enhanced Ku activity and expression were found in tumor tissue compared with normal tissue for each patient. Moreover, variations in Ku activity were found in a dose-dependent manner after the tumor cells were exposed to 1 or 2 Gy of X-rays. A decrease in phosphorylated Ku in the cytoplasm and a parallel increase in the nucleus of normal tissue cells were observed after exposure to X-rays.

CONCLUSIONS

The results of the current study suggest a possible role of Ku in regulating the DNA-PK activity of DSBs repair in bladder tumors.

Role of DNA-dependent protein kinase in recognition of radiation-induced DNA damage in human peripheral blood mononuclear cells

The DNA-dependent protein kinase (DNA-PK) complex plays a crucial role in radiation-induced DNA damage recognition. The complex includes the ku heterodimer, which comprises ku 70 and ku 80 subunits, that binds DNA termini of breaks without sequence specificity, and the catalytic subunit DNA-PKCS: The activation of the DNA-PK complex was studied in X-irradiated peripheral blood mononuclear cells (PBMC) from subjects of different ages. Radiation-induced changes in the DNA-binding activity of the ku heterodimer, and in the concentrations of ku 70, ku 80, DNA-PKcs and phosphorylated ku 80 were determined in nuclear and cytoplasmic extracts. DNA-binding activity was increased by irradiation only in the nuclear extract of PBMC from young, but not from elderly subjects, whereas it was found unchanged in cytoplasmic extracts regardless of age. The radiation-induced activation of the DNA-PK complex may result from the increased concentrations of ku 80 and DNA-PKcs in the cytoplasm of PBMC from young, but not from elderly subjects, leading to a higher concentration of phosphorylated ku 80 which readily migrates to the nucleus where, after dimerization with ku 70, binds to DNA breaks. These findings suggest major steps involved in DNA-PK activation, and the intracellular and molecular changes that may account for the age-dependent impairment of DNA repair capacity in irradiated mammalian cells.

Review and evaluation of anatomy sites on the Internet (updated 1999)

In a preceding study, we had reviewed and evaluated the anatomy sites available on the Internet. The evolution of the available sites, the disappearance of certain sites and the appearance of new sites led us to update this list. In addition, the German-speaking sites were included in the study, which previously included only the Anglophone and French-speaking sites. Forty-eight sites were indexed and their addresses are available on the site of the Laboratory of Anatomy of the Faculty of Medicine Lyon-Nord (http://rockefeller.univ-lyon1.fr/Anatomie-Lyon- Nord). Compared to the scores allotted in 1998, we noted in 1999 a significant increase (p = 0.03) in the total score (12.13 +/- 2.98 vs. 11.23 +/- 2.28/20), which shows that the quality of the anatomic sites available on the Internet has improved.

Modulation of X-ray-induced damage recognition and repair in ageing human peripheral blood mononuclear cells by an interleukin-6-type cytokine

We have investigated the effects of an interleukin (IL)-6-type cytokine on the DNA-binding activity of ku and on unscheduled DNA repair in X-ray-treated peripheral blood mononuclear cells (PBMC) from human subjects of different ages. The cytokine used, called K-7/D-6, is an IL-6 variant with increased in vivo and in vitro biological activity compared to the wild type molecule. Ku is the DNA-binding component of the DNA-dependent protein kinase (DNA-PK). It binds the ends of various types of DNA discontinuity and is involved in the repair of DNA breaks caused by V(D)J recombination, isotype switching, physiological oxidation reactions, ionizing radiation and some chemotherapeutic drugs. The ku-dependent repair process, called non-homologous end joining, is the main DNA double strand break repair mechanism in irradiated mammalian cells. Results show that K-7/D-6 significantly increases DNA-binding activity of ku in irradiated PBMC from young but not from elderly subjects. However, K-7/D-6 is able to induce unscheduled DNA repair in irradiated PBMC from both young and elderly subjects. These effects of K-7/D-6 are relevant to the mechanisms of the cellular response to DNA damage.

Psychoneuroimmunology and aging

BACKGROUND

The senescence of the immune system is a complex phenomenon, characterized by impairment of several lymphocyte activities and generally considered a state of immune dysregulation. Aging is a condition associated with many social changes likely to induce psychological stress, which is often perceived as uncontrollable and can lead, in some cases, to clinically relevant depression. In the recent years a growing interest has been raised for the study of bidirectional interactions between the central nervous system and the immunological network (psychoneuroimmunology).

OBJECTIVE AND METHODS

We analyzed the possibility that chronic psychological distress and depression could worsen some immune functions in the aged. We postulate the neuroendocrine mechanisms of psychoimmune interaction, analyzing both the human and animal studies focused on aging.

RESULTS

The data from the literature reviewed suggest a significant impact of affective disorders on immune functions in the elderly subjects. This psychoimmune imbalance appears particularly important when the studies are carried out in otherwise healthy aged people.

CONCLUSIONS

Here we reviewed the relationships between psychological stress and depression and immunological functions, with particular regard to those aspects pertinent to the aging process. The clinical relevance of these interactions remains to be elucidated, but the high frequency in the aged of autoimmune, infectious, and neoplastic diseases suggests to focus on the psychoneuroimmune interactions in the old age. We also propose some outlines for future studies concerning psychoneuroimmunology and aging.

Genetic factors in immunity and aging

Maximum life span is controlled by genes that regulate molecular mechanisms accounting for the synchrony of structural and functional changes in different cells and tissues of each member of a given species. The role of immune response genes was investigated in aging mice genetically selected for high (H) or low (L) antibody response (Biozzi mice). Results from genetic selection of over 1000 mice showed that genes expressed in the immune system affect life span and diseases. In most cases, the life span is longer in H than in L mice whereas the lymphoma incidence is remarkably higher in L than in H mice. Since DNA repair capacity is a property positively correlated with the maximum life span in several mammalian species, DNA repair was studied by use of hydroxyurea, a cell-synchronizing agent, and found to take place in irradiated human PBMC from young and, to a lesser extent, from adult subjects. Conversely, no repair was detected in irradiated PBMC from elderly subjects. DNA damage recognition and repair pathways involve several nuclear proteins, as double strand breaks are firstly recognized by proteins displaying helicase activity, such as ku 70/80, and then repair is carried out under the control of other proteins. Radiation-induced expression of activated ku(70/80) proteins, in terms of DNA-binding, was found in PBMC from young-adults but not from elderly subjects. Maintenance of DNA integrity is fundamental for normal immune functions, as suggested by the lack of V(D)J recombination in lymphocytes of knock-out mice deficient in ku 70 or ku 80 protein. However, whether the link between genetic factors and life span is mediated by the performance of the immune system remains to be demonstrated.

Hematopoietic reconstitution after lethal irradiation and bone marrow transplantation: effects of different hematopoietic cytokines on the recovery of thymus, spleen and blood cells

Lethally irradiated mice were grafted with syngeneic bone marrow cells or left ungrafted. Mice of each group were injected with different hematopoietic cytokines for 5 consecutive days starting immediately after irradiation or left uninjected. The recovery of lymphoid tissues induced by hematopoietic cytokines 7 days after irradiation and bone marrow cell transplantation was comparable to that observed at days 21-28 in irradiated, bone marrow-grafted, but cytokine-uninjected mice. IL-11 or IL-6, in combination with IL-3, was able to hasten thymus, spleen and blood cell numbers and functions. SCF also displayed a detectable effect when used with IL-3. Conversely, the IL-6 superagonist K-7/D-6 was able, when injected alone, to induce significant recovery of thymus, spleen and blood cells. Thus, K-7/D-6 appears to be a most efficient cytokine for fast reconstitution of lymphoid tissues after irradiation and bone marrow transplantation.

Neuropeptide Y plasma levels and immunological changes during academic stress

Academic stress is a good model of psychological stress in humans for studying psychoneuroimmune correlations. We looked for correlations between psychological scores, immune tests and plasma levels of cortisol and neuropeptide Y (NPY). A group of medical students were evaluated at the beginning of the academic year (Baseline) and the day before an examination (Stress). They underwent evaluation by The Profile of Mood States (POMS), The Malaise Inventory, The Self Efficacy Scale and A Global Assessment of Recent Stress (GARS). The lymphocyte subsets, the lymphocyte proliferative response and the cytokine production were also evaluated. We detected modifications of some psychological test scores between the Baseline and Stress evaluation, a significant reduction of lymphocyte proliferation, IL-2 production and percentage of the lymphocyte CD19, and an increase in plasma cortisol levels during stress. The lymphocyte proliferation negatively correlated with the POMS score as well as the percentage of CD16+ cells with NPY plasma levels. NPY levels were not different from Baseline. The emotional and mood states seem to influence immunity. Copyrightz1999S.KargerAG,Basel

Haemopoietic reconstitution after sublethal irradiation: comparison of the effects of different haemopoietic cytokines on murine lymphocytes and bone marrow cells

Sublethally irradiated mice were injected with recombinant cytokines to stimulate haemopoietic reconstitution. Interleukin (IL)-11 and IL-6 were able to significantly accelerate the recovery of thymus, spleen and bone marrow cells when used in combination with IL-3, but not alone. Stem cell factor (SCF) also displayed detectable effects when used with IL-3. Conversely, the IL-6 superagonist K-7/D-6 was able, even when used alone, to induce recovery of thymus, spleen and bone marrow cells up to the level of unirradiated controls. Together, these results indicate that it is possible to attain complete recovery of lymphoid organs and tissues as early as 7 d after irradiation by use of haemopoietic cytokines.

Effect of age on DNA binding of the ku protein in irradiated human peripheral blood mononuclear cells (PBMC)

DNA binding of the ku protein was investigated in peripheral blood mononuclear cells (PBMC) from 24 subjects of different ages (20-89 years old) displaying age-related changes in DNA repair, mitotic responsiveness, and cytokine production. Ku is an heterodimeric protein composed of two subunits of 70 and 80 kDa, which is involved in the earliest steps of DNA damage recognition. DNA binding of ku 70/80 was found unchanged in normal PBMC from aging subjects but progressively declined in x-ray-irradiated PBMC from young to adult, and elderly subjects. This finding was concomitant with the age-related fall of DNA repair in the whole population.

Characteristics of gastric-vein lymphocytes with regard to the immune response to Helicobacter pylori

BACKGROUND

Between peripheral blood and tissue-infiltrating lymphocytes there is an intermediate compartment, the blood of the organ-draining vessels, which could show unusual features. The aim of the present study was to analyse the characteristics of the lymphocytes from the stomach-draining vessels and the cytokine secretion by these lymphocytes. The CagA-mediated lymphocyte activation in Helicobacter pylori-infected subjects and the humoral response to this antigen were evaluated and correlated with clinical data.

METHODS

We studied lymphocyte proliferation either with mitogens or with the CagA antigen and cytokine production and IgG anti-CagA by means of an enzyme-linked immunosorbent assay in peripheral blood and gastric-vein blood obtained during surgical intervention.

RESULTS

We showed higher proliferative response and cytokine production in lymphocytes from the gastric vein. The mitogenic response to the CagA antigen was highly specific but poorly sensitive for the H. pylori infection in both the compartments. The overall cytokine profile in our patients affected by non-ulcer disease was of the Th0 type.

CONCLUSIONS

Gastric-vein-derived lymphocytes seem to show unusual features, as they behave like peripheral blood lymphocytes but show higher responses to all the tested stimuli. It is possible that the interaction of the lymphocytes with the mucosal environment could activate the synthetic mechanisms, making the cells more 'responsive' to the stimulation. The CagA antigen is able to induce a specific T-lymphocyte response and is therefore a valid candidate antigen for the development of a vaccine.