Two New Species of the Spittlebug Genus Ocoaxo Fennah (Hemiptera: Cercopidae) from Mexico, and Keys for the Groups, Group Three, and First Subgroup.

Insects of the family Cercopidae are known as spittlebugs or froghoppers and are represented by 62 genera in the Neotropical region. One of these genera is Ocoaxo Fennah, 1968 with 30 species. The most recent species to be accepted into this genus, Ocoaxo costaricanus, was described by Nast (Ann Zool 33:93-101, 1975). Herein, two new species of Ocoaxo from Mexico are described. One of these new species forms a complex together with Ocoaxo assimilis (Walker) and Ocoaxo varians (Stål). The complex has economic importance in the mountainous areas of the states of Puebla and Oaxaca because it attacks Pinus spp. and causes a disorder called "pine decline." Additionally, dichotomous keys were designed to identify the Ocoaxo Fennah groups and also the species of the subgroup bivittus.

The economic efficiency and equity of government policies on brucellosis: comparative insights from Albania and the United States of America.

Brucellosis is a zoonotic bacterial disease that causes recurring febrile illness in humans, as well as reproductive failure and reduced milk production in livestock. The cost of brucellosis is equal to the sum of lost productivity of humans and animals, as well as private and public expenditures on brucellosis surveillance, prevention, control and treatment. In Albania, Brucella abortus and B. melitensis affect humans, cattle and small ruminants. In the United States, B. abortus affects cattle and wild ungulates in the Greater Yellowstone Area. These two case studies illustrate the importance of place-specific context in developing sustainable and effective brucellosis mitigation policies. Government regulations and mitigation strategies should be designed with consideration of all costs and benefits, both to public agencies and private stakeholders. Policy-makers should, for example, weigh the benefits of a regulation that increases epidemiological certainty against the costs of compliance for producers and households. The distribution of costs and benefits amongst public agencies and private individuals can have important implications for a policy's economic efficiency and equity quite apart from their total magnitude.

La brucellose est une maladie bactérienne zoonotique responsable d'épisodes fébriles récurrents chez l'être humain ainsi que d'infertilités et d'une baisse de la production de lait chez les animaux d'élevage. Le coût de la brucellose équivaut à la somme des pertes de productivité chez l'homme et chez les animaux et des dépenses privées et publiques engagées dans la surveillance, la prévention, la prophylaxie et le traitement de la brucellose. En Albanie, Brucella abortus et B. melitensis affectent aussi bien l'être humain que les bovins et les petits ruminants. Aux États-Unis d'Amérique, B. abortus affecte les bovins et les ongulés sauvages de la région du Grand Yellowstone. Les deux études de cas présentées dans cet article illustrent l'importance de prendre en compte le contexte spécifique de chaque site particulier lors de la mise en place de politiques durables et efficaces d'atténuation de la brucellose. La réglementation et les stratégies d'atténuation mises en oeuvre par les pouvoirs publics doivent être conçues en considérant l'ensemble des coûts et des bénéfices induits pour les agences gouvernementales et les intervenants privés. Par exemple, les décideurs politiques devraient évaluer les avantages induits par une réglementation basée sur un accroissement des certitudes épidémiologiques, par rapport aux coûts supportés par les producteurs et les ménages se conformant à cette réglementation. La répartition des coûts et des bénéfices entre les agences gouvernementales et les individus privés peut avoir d'importantes répercussions sur l'efficacité économique et l'équité d'une politique sanitaire, indépendamment de leur amplitude totale.

La brucelosis es una enfermedad bacteriana zoonótica que provoca dolencias febriles recurrentes en el ser humano, así como trastornos reproductores y una menor producción lechera en el ganado. Su costo es igual a la suma de las pérdidas de productividad en personas y animales, junto con el gasto público y privado dedicado a tareas de vigilancia, prevención, control y tratamiento de la enfermedad. En Albania, Brucella abortus y B. melitensis afectan a personas, ganado bovino y pequeños rumiantes. En los Estados Unidos, B. abortus afecta al ganado bovino y a ungulados salvajes de la zona del Gran Yellowstone. Los autores presentan dos estudios monográficos que ponen de relieve la importancia del contexto geográfico a la hora de definir políticas duraderas y eficaces para mitigar la brucelosis. Al elaborar tanto reglamentos como estrategias públicas de mitigación es preciso tener en cuenta la totalidad de los costos y beneficios, a la vez para los organismos oficiales y para el sector privado. Los planificadores deben, por ejemplo, sopesar los beneficios derivados de un reglamento que aporte mayor certidumbre epidemiológica en relación con los costos que entrañe su aplicación para productores y familias. La forma en que costos y beneficios se distribuyan entre organismos públicos y personas físicas puede influir sustancialmente en los niveles de eficiencia económica y equidad de una política, con independencia de su magnitud total.

Improving preclinic preparation for patients with chronic conditions in quito, ecuador: a randomized controlled trial.

Objectives. As in many settings, patients in community health centers in Ecuador do not complete previsit forms or receive assistance to identify questions and concerns they would like to address in brief clinic visits with physicians. We examined the comparative effectiveness of providing (1) a previsit form to complete; (2) a previsit form along with assistance in completing the form; and (3) usual care. Methods. Parallel, three-arm randomized controlled trial in two health centers serving indigent to low-income communities in Quito, Ecuador, among 199 adult patients who took medications for at least one chronic condition. Outcome measures were self-reported satisfaction with the visit, confidence in asking questions, and extent to which patients' objectives were met. Results. Patients who received assistance in completing a previsit form were more than twice as likely as participants in usual care to report achieving everything they wanted during their visit (AOR 2.2, P = 0.039). There were no differences in any outcomes between the groups who received the previsit form with no assistance and usual care. Conclusions. For high-quality patient-centered primary care, it is important to develop and test innovative and scalable interventions for patients and physicians to make the best use of limited clinic time.

Early-onset LBSL: how severe does it get?

AIM: Leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation (LBSL) is known as a relatively mild leukoencephalopathy. We investigated the occurrence of severe variants of LBSL with extensive brain magnetic resonance imaging (MRI) abnormalities. METHOD: MRIs of approximately 3,000 patients with an unknown leukoencephalopathy were retrospectively reviewed for extensive signal abnormalities of the cerebral and cerebellar white matter, posterior limb of the internal capsule, cerebellar peduncles, pyramids, and medial lemniscus. Clinical data were retrospectively collected. RESULTS: Eleven patients fulfilled the MRI criteria (six males); six had DARS2 mutations. Clinical and laboratory findings did not distinguish between patients with and without DARS2 mutations, but MRI did. Patients with DARS2 mutations more often had involvement of structures typically affected in LBSL, including decussatio of the medial lemniscus, anterior spinocerebellar tracts, and superior and inferior cerebellar peduncles. Also, involvement of the globus pallidus was associated with DARS2 mutations. Earliest disease onset was neonatal; earliest death at 20 months. INTERPRETATION: This study confirms the occurrence of early infantile, severe LBSL, extending the known phenotypic range of LBSL. Abnormality of specific brainstem tracts and cerebellar peduncles are MRI findings that point to the correct diagnosis.

TU-E-217A-01: Informatics 1: DICOM and the QMP, Assessment of Color Displays.

All Medical Physicists work with the DICOM Standard every day. But the involvement of Medical Physicists in the development of the Standard has been limited. Recently the DICOM Standards Committee (DSC) has established a new Dicom Working Group on Physics (i.e. WG28) and the AAPM has become the secretariat for WG28 and a voting member of the DSC. The structure and processes involved with making the DICOM Standard will be reviewed and the specific role DICOM WG28 has will be summarized. LEARNING OBJECTIVES: 1. Understand the processes involved with development of the DICOM Standard. 2. Learn how any Medical Physicist can become involved in the process of developing the DICOM Standard 3. Learn the charge and structure of WG28 and their current Work Items. Medical color monitors are now widely used for Diagnostic Radiology interpretations. Business class monitors are otherwise used for medical image presentation in clinical departments. Both the AAPM and IEC are now developing recommendations and standards for color monitor performance assessment in medicine. The basic principles of color vision and metrology will be reviewed and current progress with AAPM and IEC working groups will be summarized. LEARNING OBJECTIVES: 1. Understand the tristimulus model for human color vision. 2. Understand the ICC color management framework. 3. Understand the ICC color management framework. 4. Learn how to make color measurements. 5. Learn new recommendations for color white point specification.

Neonicotinoid insecticides disrupt predation on the eggs of turf-infesting scarab beetles.

Turfgrass applications of imidacloprid were previously shown to suppress the abundance of certain soil arthropods. To ascertain whether those impacts harbor functional consequences, the effect of neonicotinoids on Japanese beetle (Popillia japonica Newman) predation was examined in three experiments that measured removal of eggs implanted into non-irrigated field plots. A first experiment confirmed that a single imidacloprid application reduced the abundance of nontarget fauna and the rate of egg removal. A second experiment compared the impacts of imidacloprid with those of three other neonicotinoids, while a third measured the impact of imidacloprid when applied in July, August or September. Egg removal declined 28.3-76.1% in imidacloprid-treated plots across all studies. Effects were detected as early as one week after treatment (WAT) and persisted as long as four WAT. The extent of suppression did not vary across month of application. Clothianidin, dinotefuran and thiamethoxam also suppressed egg removal, and the effects were similar among them and with imidacloprid. There was no discernible association between variation in rainfall and treatment effects, but this was not explicitly tested. Results support the hypotheses that a single neonicotinoid application can suppress predation on pest populations and that the effect does not vary with respect to active ingredient or season of application. Neonicotinoid application at the time of beetle oviposition puts intended effects (mortality of neonates) in conflict with unintended effects (disruption of egg predation). The conservation of predation on early life stages might buffer the reduced efficacy of late season applications that target more advanced instars. As application timing and post-application irrigation affect insecticide performance, they might also be manipulated to reduce nontarget effects.

Clinical, enzymatic and molecular characterization of nine new patients with malonyl-coenzyme A decarboxylase deficiency.

We report nine new patients with malonic aciduria associated with enzyme-confirmed malonyl-CoA decarboxylase (MCD) deficiency in eight. Clinical details were available on eight, and molecular genetic characterization was obtained for nine. As for 15 previously described patients, cardinal clinical manifestations included developmental delay and cardiomyopathy; metabolic perturbations (e.g. acidosis) and seizures, however, were infrequent or not observed in our patients. For all, detection of elevated malonic acid in urine (+/- increased C3DC acylcarnitine by analysis employing tandem mass spectrometry) led to pursuit of enzyme studies. MCD activities (nmol/h PER mg protein) revealed: control (n = 22), 16.2 +/- 1.8 (SEM; range 5.7-46.2); patients (n = 8, assayed in duplicate), 1.7 +/- 0.3 (10% of parallel control; range 0.6-2.8). Molecular characterization by DNA sequence analysis and multiplex ligation-dependent probe amplification revealed nine novel mutations (c.796C>T; p.Gln266X, c.481delC; p.Leu161CysfsX18, c.1367A>C; p.Tyr456Ser, c.1319G>T; p.Ser440Ile, c.1430C>T; p.Ser477Phe, c.899G>T; p.Gly300Val, c.799-1683_949-1293del3128, and two other large genomic deletions comprising exons 1 or the complete gene) and two known mutations in the MLYCD gene. Our findings increase the number of enzyme-confirmed MCD-deficient patients by >50%, and expand our understanding of the phenotypic and molecular heterogeneity of this rare disorder.

Intraperitoneal aerosolization of bupivacaine reduces postoperative pain in laparoscopic surgery: a randomized prospective controlled double-blinded clinical trial.

BACKGROUND: Laparoscopic strategies for managing intraabdominal pathologies offer significant benefits compared with conventional approaches. Of interest are reports of decreased postoperative pain, resulting in shorter hospitalization and earlier return to normal activity. However, many patients still require strong analgesia postoperatively. This study analyzed the use of intraoperatively delivered aerosolized intraperitoneal bupivacaine and its ability to reduce postoperative pain. METHODS: For this study, 80 patients undergoing laparoscopic cholecystectomy were recruited and divided randomly into four groups: control (n = 20), aerosolized bupivacaine (n = 20), aerosolized normal saline (n = 20), and local bupivacaine in the bladder bed (n = 20). All the patients had standard preoperative, intraoperative, and postoperative care. Pain scores were recorded by the nursing staff in recovery, then 6, 12, and 24 h postoperatively using a standard 0 to 10 pain scoring scale. In addition, opiate consumption and oral analgesia were recorded. RESULTS: Aerosolized bupivacaine significantly reduced postoperative pain in comparison with all other treatments (p < 0.05). Injection of bupivacaine into the gallbladder bed did not result in a significant difference from the control condition. CONCLUSION: Aerosolized intraperitoneal local anesthetic is an effective method for controlling postoperative pain. It significantly helped to reduce opiate use and contributed to rapid mobilization, leading to short hospitalization and possible reduction in treatment cost.

A surgically induced hypoxic environment causes changes in the metastatic behaviour of tumours in vitro.

The use of laparoscopic techniques for curative resections of malignant tumours has been under scrutiny. The potential benefits to the patient in the form of earlier recovery and less immune paresis are countered by the reports of increased tumour recurrence. The biological sequelae of the hypoxic laparoscopic environment on tumour cells is unknown. Components of the metastatic cascade were evaluated under in vitro laparoscopic conditions using a human colonic adenocarcinoma cell line (SW1222). Exposure to the laparoscopic gases carbon dioxide and helium for 4 h, comparable to the duration of a laparoscopic colorectal resection, had no effect on cell viability. A cellular hypoxic insult was demonstrated by the induction of hypoxia inducible factor 1alpha (HIF-1alpha). Exposure also resulted in significant reduction in homotypic adhesion as well as to a variety of extracellular matrix components. These effects were recoverable under re-oxygenation. The changes were reflected at the molecular level by significant down regulation of adhesion molecules known to be involved in tumour progression (E-cadherin, CD44 and beta1 sub-unit). Modulation of adherence has significant implications for laparoscopic oncological surgery, demonstrating that tumours become potentially more friable and easier to disseminate in surgeons who are less experienced or where instrumentation is sub-optimal.

Peritoneal nebulizer: a novel technique for delivering intraperitoneal therapeutics in laparoscopic surgery to prevent locoregional recurrence.

BACKGROUND: Peritoneal involvement is a significant issue in the treatment of gastrointestinal malignancies. Current statistics indicate that after surgical intervention, up to 20% of patients will present with locoregional metastasis. The ability to inhibit initial tumor adhesion to the mesothelial lining of the peritoneum may be considered critical in the inhibition of tumor development. This article describes, the use of a novel nebulizer system capable of delivering high-concentration, low-dose therapeutics to the peritoneal cavity. METHODS: For this study, 30 male WAG rats were inoculated with CC531 colorectal tumor cells. The rats were randomized into three groups: control group (n = 10), heparin-treated group (n = 10), and high-molecular-weight hyaluronan-treated group (n = 10). A peritoneal cancer index was used to determine tumor burden at 15 days. Analysis of variance (ANOVA) was used to compare multiple group means. RESULTS: Nebulization therapy was performed without any complication in the cohort. Heparin inhibited macroscopic intraperitoneal tumor growth completely (p = 0.0001) without affecting tumor cell viability. The introduction of hyaluronan attenuated both tumor size and distribution, was compared with the control group (p = 0.002). CONCLUSION: Nebulized heparin and hyaluronic acid using a novel nebulization technique attenuates peritoneal tumor growth after laparoscopic surgery. The technique itself is easy to use and safe.

Laparoscopic environmental changes during surgery enhance the invasive potential of tumours.

OBJECTIVE: The use of laparoscopic techniques in resection of malignant tumours has been proposed to offer potential benefit to the patient in the form of earlier recovery and less immune paresis; however, reported tumour seeding, both peritoneal and at port site, has put this approach into question. The biological effects of the introduction of carbon dioxide or helium to form a pneumoperitoneum on tumour invasion and dissemination are unknown. METHODS: A human colonic adenocarcinoma cell line (SW1222) was exposed to in vitro laparoscopic environment of either carbon dioxide or helium for 4 h, mimicking the duration of a laparoscopic colorectal resection. Alteration in production of matrix metalloproteinase (MMP)-2, MMP-9 and urokinase-type plasminogen activator (uPA) due to exposure to a laparoscopic environment was determined by zymography and correlated to invasive capacity by a standard Matrigel-based invasion assay. Incorporation of specific gelatinase inhibitors or antibodies directed at the uPA receptor was utilized to determine the relative importance of proteases. RESULTS: Exposure to the laparoscopic environment significantly enhanced production of the proteases MMP-2, MMP-9 and uPA. A concomitant enhancement of invasive capacity was also observed, being blocked by specific protease inhibitors. Changes in both protease production and aggression were observable for at least 24 h following the removal of the operative environment, indicating the possible long-term effects of the initial insult. CONCLUSION: Exposure to the laparoscopic environment enhances the invasive capacity of colonic adenocarcinomas via a well-defined protease-determined pathway. It therefore appears likely that tumour cells released into the operative field can be made increasingly aggressive by a laparoscopic operative environment and can thus contribute to disease dissemination.

Variant Creutzfeldt-Jakob disease: a cause for concern. Review of the evidence for risk of transmission through abdominal lymphoreticular tissue surgery.

BACKGROUND: Concern has long existed regarding the possible iatrogenic spread of variant Creutzfeldt-Jakob disease (v-CJD) through surgery. This had been fueled by recent reports of bovine spongiform encephalopathy in U.S. cattle and the first probable case of blood transmission of v-CJD in the UK. METHODS: Systematic review of experimental and nonexperimental studies. Studies identified from searches of Medline, Embase, Cochrane Library, Science Citation Index medical databases, searching bibliographies of retrieved papers, and personal communication with international experts in the field. RESULTS: Six articles satisfied our search criteria. Evidence stems from case reports, case series, and cross-sectional studies. There are no published cases of surgically transmitted v-CJD. CONCLUSION: We found evidence of v-CJD prion agents in the spleen, appendix, rectum, and adrenal glands of affected patients and evidence of v-CJD prion in the appendix of patients in the preclinical stage of the disease. The risk of transmission of v-CJD prion during abdominal surgery is currently unquantifiable.

Craniomaxillofacial injury in sport: a review of prevention research.

Current decision making in prevention of sport related craniomaxillofacial injury is based on available data derived from surveillance and attitude based studies. The literature on this type of injury prevention lacks the high quality scientific design and evidence on which mandatory interventions can be based. Currently available prevention methodology can provide a better understanding of injury mechanisms and produce valid interventions.

Perioperative diagnosis of cystosarcoma phyllodes of the breast may be enhanced by MIB-1 index.

BACKGROUND: The recurring theme in cystosarcoma phyllodes (CSP) is one of underdiagnosis by pathologists and undertreatment by surgeons. Major areas of investigation relating to the diagnosis of CSP center on accurate preoperative diagnosis, elucidating the relevance of histological classification with respect to outcome, and identifying novel markers to reliably differentiate CSP from fibroadenoma (FA). MATERIALS AND METHODS: Fifteen CSP and 7 cellular FA controls (where the preoperative diagnosis was unclear) were retrospectively investigated. Preoperative histological and radiological investigations were reviewed for efficacy. The ability of MIB-1 antibody to differentiate the two fibroepithelial lesions was investigated using immunohistochemical estimation of the MIB-1 index. RESULTS AND DISCUSSION: Preoperative core biopsy had a sensitivity of 75% but was carried out in only 23% of cases. Fine needle aspiration cytology and radiological assessment were not efficacious in preoperative diagnosis. Proliferative activity (MIB-1 indices) was significantly higher in CSP than in a selected population of FA where there was preoperative diagnostic uncertainty (P < 0.0001). Indices were also able to determine CSP subclassification. This suggests MIB-1 as a constructive adjunctive investigation when evaluating histological features to differentiate CSP from FA in difficult cases. CONCLUSIONS: The use of MIB-1 may increase the sensitivity of preoperative core biopsy diagnosis, offering more effective surgical planning and decreasing immediate reoperation rates.

The relationship between plasma MMP-1, -7, -8 and -13 levels and embolic potential during carotid endoluminal intervention.

BACKGROUND: Patients undergoing carotid endoluminal intervention are at risk of embolic stroke even with the use of distal protection devices. Matrix metalloproteinases (MMPs) have been implicated as a causal factor in plaque instability leading to spontaneous embolisation. We investigated whether plasma MMP levels correlated with the embolisation during carotid endoluminal intervention. METHODS: Thirty circumferentially intact carotid endarterectomy specimens were subjected to a standardised angioplasty procedure in a pulsatile ex vivo model. Emboli collected in a series of distal filters were counted and sized. Plasma samples were collected pre-operatively and analysed for MMP-7 and MMP-8 levels using Western immunoblotting. MMP-1 and MMP-13 levels were determined using ELISA. Emboli number and maximum size were correlated with plasma levels of the MMPs using Spearmans rank. RESULTS: Total MMP-8 levels were related to maximum embolus size (r=0.442, p=0.005) but not emboli number (r=0.342, p=0.052). MMP-1, -7 and -13 were not correlated with either emboli number or with maximum embolus size. CONCLUSION: Pre-operative plasma MMP-8 levels are related to the size of emboli from plaques during carotid endovascular intervention. Further in vivo studies need to be performed to assess the importance of this finding. There is potential for development of plasma markers to identify those patients at greater risk of embolic stroke during carotid endoluminal intervention.

Laparoscopic enhancement of tumour cell binding to the peritoneum is inhibited by anti-intercellular adhesion molecule-1 monoclonal antibody.

BACKGROUND: There still remain some concerns over the phenomenon of port-site metastases (PSM) after laparoscopic surgery. The aim of this study was to investigate the effect of the pneumoperitoneum on tumor-mesothelial cell interactions. METHODS: The adhesion of a colon carcinoma cell line to a mesothelial cell monolayer exposed to carbon dioxide, helium, or air was assessed using an in vitro adhesion assay. Changes in adherence were correlated with alterations in cell surface molecule expression by the mesothelial cells using flow cytometry after exposure to the different environments. RESULTS: Exposure of the mesothelial cells to an in vitro pneumoperitoneum significantly enhanced tumor cell binding to the mesothelial cell monolayer. No differences in cell viability were observed between the groups. This was associated with increased expression of mesothelial intercellular adhesion molecule-1 (ICAM-1) mediated by nuclear factor kappa-B. The enhanced adhesion was abolished by ICAM-1 inhibition. CONCLUSIONS: This study demonstrated that the laparoscopic environment increases the susceptibility of the mesothelium to tumor cell adherence, and this may be explained by changes in ICAM-1 expression.

Laparoscopic staging of pancreatic tumors induces increased invasive capacity in vitro.

INTRODUCTION: Laparoscopy and laparoscopic ultrasound have a well-defined role in staging patients with pancreatic malignancy. The effect of the hypoxic pneumoperitoneum induction on tumor biology is unknown. The authors investigated whether an in vitro pneumoperitoneum augments the invasive capacity of pancreatic tumors and elucidate a mechanism by which this may occur. METHODS: A pancreatic (PSN-1) adenocarcinoma cell line was exposed to an in vitro pneumoperitoneum (carbon dioxide (CO2) or helium) for a maximum of 2 h or left in normal growth conditions (control). Cells were nonenzymatically harvested and placed in invasion assays. These were performed over 72 h using Matrigel coated 8-mm Transwell filters and analyzed using MTS colorimetric assay. Gelatin zymography was employed to assess the level of matrix metalloproteases (MMP) 2 and 9 (gelatinase A and B) secretion. Expression of tissue inhibitor of metalloproteases 1 (TIMP-1) was assessed using ELISA (Biotrak). Inhibition of invasion assays was performed using a specific gelatinase inhibitor (MMPI; Calbiochem). RESULTS: The invasive capacity of pancreatic tumour cells is augmented versus control in both helium (p <0.05) and CO2 (p <0.001) groups. Concomitant significant upregulation of the gelatinase activity was demonstrated with both insufflants (p <0.05; 0.001, respectively). Enhanced invasion was attenuated by the addition of a specific gelatinase inhibitor (p <0.05). CONCLUSIONS: These results indicate the invasive capacity of pancreatic tumor cells is augmented by laparoscopic staging in vitro. This is in part mediated by increased gelatinase activity and may be attenuated by the addition of specific inhibitors.

Pneumoperitoneum augmented tumor invasiveness is abolished by matrix metalloproteinase blockade.

BACKGROUND: Certain surgical strategies, including Helium (He) and carbon dioxide (CO2) insufflation in laparoscopy, have been shown to induce a hypoxic environment. This may have a significant effect on the invasive capacity of tumor cells and may be a factor in the incidence of port-site metastases seen in patients following laparoscopic resection for malignancy. METHODS: A colon adenocarcinoma cell line (SW1222) was exposed to an in vitro pneumoperitoneum of CO2 or He at 3 mmHg or left in normal growth conditions (control). After a 4-hour exposure to an in vitro pneumoperitoneum, the ability of the cells to invade through 8.0-microm Transwell filters coated with Matrigel was analyzed by colorimetric MTS assay and by direct staining of the filters. The effect of the addition of a known blocker of matrix metalloproteinases (MMPs), 1,10-phenanthroline (1,10-P), was investigated. RESULTS: Cells exposed to an in vitro pneumoperitoneum demonstrate significantly increased invasive capacity compared to the control set, without loss of viability (He vs control, p <0.001; CO2 vs control, p <0.001). This augmented capacity is abolished by the addition of 1,10-P (p <0.01). CONCLUSION: Exposure of a colonic adenocarcinoma cell line to either a CO2 or He pneumoperitoneum causes an increase in tumor cell invasiveness, which is abolished by the presence of a known inhibitor of MMPs. This suggests that MMPs have an important role in the metastatic potential of tumors exposed to a hypoxic operative environment.

Intraperitoneal hypothermia during surgery enhances postoperative tumor growth.

BACKGROUND: Recent work has shown that intraoperative hypothermia is a significant source of surgical trauma, with wide-ranging physiological and immunological sequelae. The aim of this study was to examine the effects of intraperitoneal hypothermia during laparoscopy on tumor growth in an animal model. METHODS: Thirty WAG rats were randomized to undergo anesthesia alone (n = 10), insufflation with cold carbon dioxide (CO2) (n = 10), or insufflation with warm CO2 (n = 10). During insufflation, 1 x 105/ml CC531s colon cancer cells in suspension were injected into the peritoneal cavity. The control group was anesthetized and tumor cells were injected without insufflation. After 3 weeks, total tumor weight and the extent of tumor spread, as assessed by the modified Peritoneal Cancer Index (PCI), were compared at autopsy. RESULTS: Laparoscopy with cold CO2 resulted in a significant reduction in local and core body temperatures (p <0.05). Tumor growth in both groups that underwent CO2 pneumoperitoneum was significantly increased compared with the group that did not (p <0.0001, control vs warm CO2 and cold CO2). There was significantly more tumor growth in the rats insufflated with unwarmed CO2 than in the normothermic group (mean total tumor 0.01 g +/- 0.03 vs. 0.043 g +/- 0.07; p = 0.025 Mann-Whitney U test). Tumor spread as shown by the PCI scores was less in the warm gas group than it was in the animals insufflated with cold gas (151 vs 266). CONCLUSIONS: These data demonstrate that the peritoneal insufflation of CO2 enhances tumor growth and that the prevention of perioperative hypothermia during laparoscopy attenuates tumor growth. This effect may be partially mediated by the increased peritoneal trauma that results from insufflation with cold gas.

Evaluation of a quality control phantom for digital chest radiography.

RATIONALE AND OBJECTIVES: To examine the effectiveness and suitability of a quality control (QC) phantom for a routine QC program in digital radiography. MATERIALS AND METHODS: The chest phantom consists of copper and aluminum cutouts arranged to resemble the appearance of a chest. Performance of the digital radiography (DR) system is evaluated using high and low contrast resolution objects placed in the "heart," "lung," and "subdiaphragm" areas of the phantom. In addition, the signal levels from these areas were compared to similar areas from clinical chest radiographs. RESULTS: The test objects included within the phantom were effective in assessing image quality except within the subdiaphragm area, where most of the low contrast disks were visible. Spatial resolution for the DR systems evaluated with the phantom ranged from 2.6 lp/mm to 4 lp/mm, falling within the middle of the line pair range provided. The signal levels of the heart and diaphragm regions relative to the lung region of the phantom were significantly higher than in clinical chest radiographs (0.67 versus 0.21 and 0.28 versus 0.10 for the heart and diaphragm regions, respectively). The heart-to-diaphragm signal level ratio, however, was comparable to those in clinical radiographs. CONCLUSION: The findings suggest that the attenuation characteristics of the phantom are somewhat different from actual chests, but this did not appear to affect the post-processing used by the imaging systems and usefulness for QC of these systems. The qualitative and quantitative measurements on the phantom for different systems were similar, suggesting that a single phantom can be used to evaluate system performance in a routine QC program for a wide range of digital radiography systems. This makes the implementation of a uniform QC program easier for institutions with a mixture of different digital radiography systems.