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Individuals with minor ischaemic stroke and intracranial occlusion are at increased risk of poor outcomes. Intravenous thrombolysis with tenecteplase might improve outcomes in this population. We aimed to test the superiority of intravenous tenecteplase over non-thrombolytic standard of care in patients with minor ischaemic stroke and intracranial occlusion or focal perfusion abnormality.

Background: Stroke is a leading cause of death and disability worldwide, including Canada. Treatments for stroke are time dependent and IV tPA for acute ischemic stroke decreases the chance of disability at 90 days if given within 4.5 hours of symptom onset. The onset of the Covid-19 pandemic was initially associated with a decrease in acute stroke treatment with thrombolysis across North America. These decreases seemed transient, with a rebound in numbers seen in other provinces across Canada as widespread lockdown orders were lifted. However, a rebound in thrombolysis was not seen at Royal University Hospital (RUH) in Saskatoon, Saskatchewan during the same period. We will analyze documented reasons why thrombolysis was withheld. Methods: We conducted a retrospective chart review of adult patients with ischemic strokes presenting within 4.5 hours of symptom onset to the RUH from March 2019 –January 2021. We received a waiver of consent from the Research Ethics Board. Results: 128 patients met the inclusion criteria. Statistical analysis is currently ongoing. Conclusions: Initial results suggest that there are similar reasons for withholding tPA before and after the Covid-19 pandemic. The main reasons include rapidly resolving/resolved symptoms and a documented tPA exclusion criterion.

Alternative methods to alleviate coccidiosis in broilers are of interest to producers, including dietary strategies to minimize disruptions in growth rate and efficiency when faced with health challenges. Our objective was to determine optimal combinations of dietary starch, amino acids (AA), and oil to benefit productivity of broilers experiencing Eimeria-induced immune activation. Two trials were conducted using 1,536 male Ross 308 broiler chicks in floor pens randomly assigned to 1 of 17 experimental treatments. All birds received common starter (d 0–10) and finisher (d 24–35) diets, and only differed based on their assigned experimental grower diet (d 10–24). Trial 1 experimental grower diets ranged from 2,700 to 3,300 kcal/kg AME. Trial 2 included 10 experimental grower diets following a simplex lattice design consisting of 3 basal lots formulated to have the highest starch (45.4%), oil (10.2%), or AA density (120, 1.33% digestible Lys) and mixed in 4 equally spaced levels for each component (0, 0.33, 0.67, 1). These mixtures enabled varying densities of AA (80–120% of recommendation), starch:oil (4:1–20:1), and AME (2,940–3,450 kcal/kg). Bird and feeder weights were collected on d 0, 10, 24, and 35, and birds were exposed to an Eimeriachallenge on d 11 or 12. In trial 2, excreta samples were collected for AME determination and carcasses were processed on d 36. Data were analyzed using ANOVA, ttest, or regression. In Trial 1, BW gain and feed conversion were improved (P< 0.05) by increasing dietary AME. In Trial 2, birds receiving diets containing AA at 93 to 107% of recommendations and higher oil exhibited improved (P< 0.05) performance, but increased starch at the expense of oil reduced performance (P< 0.05). Relative breast and fat pad weights were not influenced by diet in Trial 2. We determined that broilers mildly challenged with Eimeriawould exhibit highest BW gain when receiving diets containing 35.8% starch, 8.9% oil, and 101.3% of AA recommendations, which can be utilized by producers to maintain productivity under health-challenged conditions.

Background: While mechanical thrombectomy (MT) has become broadly used, many nuances around its performance are still contentious. In particular, the optimal sedation strategy for MT is not clear in the literature. Methods: This study was a single-center retrospective cohort study of a prospectively collected database. Age, gender, pre-treatment NIH stroke score (NIHSS), Alberta stroke program early score CT (ASPECTS), quality of collateralization, whether the patient underwent thrombectomy, tandem carotid occlusion, and thrombolysis in cerebral infarction (TICI) score were recorded in the database. Results: We identified 228 patients having anterior circulation mechanical thrombectomy (MT). 91 were right-sided, 108 were left-sided. Collaterals were graded as good in 135 (71.4), moderate in 44 (23.2%), and poor in 10 (5.3%). The average pre-MT ASPECTS was 8.1 (range). We found significant differences between all patients, patients with good outcome (mRS 0-2) and death in age, baseline NIHSS, collateralization, and TICI revascularization score. Multivariate analysis was performed with showed significant associations of sidedness, collateralization, TICI score and hemorrhage with neurological outcome. Right-sided stroke, better collaterals, higher TICI score and absence of hemorrhage were associated with better outcomes. Conclusions: We found comparable outcomes to those reported in the literature with use of general anesthetic. We identify several factors that influence outcomes.

Abstract: Introduction: Plasma VEGF levels increase after minimally invasive colorectal resection (MICR) and remain elevated for 2–4 weeks. VEGF induces physiologic and pathologic angiogenesis by binding to endothelial cell (EC) bound VEGF-Receptor-1 (VEGFR1) and VEGFR2. Soluble forms of these receptors sequester plasma VEGF, decreasing the amount available to bind to EC-bound receptors. Ramifications of surgery-related plasma VEGF changes partially depend on plasma levels of sVEGFR1 and sVEGFR2. This study assessed perioperative sVEGFR1 and sVEGFR2 levels after MICR in patients with colorectal cancer. Methods: Forty-five patients were studied; blood samples were taken from all patients preoperatively (preop) and on postoperative days (POD) 1 and 3; in most a fourth sample was drawn between POD 7–30. Late samples were bundled into two time points: POD 7–13 and POD 14–30. sVEGFR1 and sVEGFR2 levels were measured via ELISA. sVEGFR2 data are reported as mean ± SD and were assessed with the paired samples t test. sVEGFR1 data were not normally distributed. They are reported as median and 95% confidence interval (CI) and were assessed with the Wilcoxon signed-Rank test (p < 0.05). Results: Preoperatively, the mean plasma sVEGFR2 level (7583.9 pg/ml) was greater than the sVEGFR1 result (98.3 pg/ml). Compared with preop levels, sVEGFR2 levels were significantly lower on POD 1 (6068.2 pg/ml, ±2034.5) and POD 3 (6227.6 pg/ml, ±2007.0), whereas sVEGFR1 levels were significantly greater on POD 1 (237.5 pg/ml; 95% CI, 89.6–103.5), POD 3 (200.2 pg/ml; 95% CI, 159–253), and POD 7−13 (102.9 pg/ml; 95% CI, 189.7–253). No differences were found on POD 7–13 for sVEGFR2 or POD 14–30 for either protein. Conclusions: sVEGFR2 values decreased and sVEGFR1 levels increased early after MICR; sVEGFR2 changes dominate due to their much larger magnitude. The net result is less plasma VEGF bound by soluble receptors and more plasma VEGF available to bind to ECs early after surgery.

Abstract: Background: Many surgeons rely on the umbilicus when determining the location of ports for laparoscopic procedures and falsely assume that it is located in the vertical midline. The purpose of this study was to assess the degree of variation in umbilical position and abdominal dimensions in the general population. Methods: Torso length, abdominal girth, weight, and height were recorded for 259 patients over a 9-month period. Body mass index (BMI) was calculated and used to classify patients into four groups: underweight, normal, overweight, and obese. Results: Average umbilical position for all BMI groups was below the true vertical midpoint and dropped further caudally as BMI increased. In addition, average abdominal dimensions increased with increasing BMI. There was no statistical difference between males and females in each BMI group regarding umbilical position or abdominal dimensions. Conclusion: There is a clear relationship between increasing BMI and a drop in umbilical position as well as an increase in abdominal dimensions. We recommend determining umbilical position and abdominal dimensions prior to placing ports and shifting port positions toward target quadrants.

Abstract: Introduction: Plasma vascular endothelial growth factor (VEGF) levels are elevated for 2–4 weeks after minimally invasive colorectal resection (MICR). VEGF induces wound and tumor angiogenesis by binding to endothelial cell (EC)-bound VEGF-receptor 1 (VEGFR1) and VEGFR2. Soluble receptors (sVEGFR1, sVEGFR2) sequester VEGF in the blood and decrease VEGF’s proangiogenic effect. The importance of the MICR-related VEGF changes depends on the effect of surgical procedures on sVEGFR1 and sVEGFR2; this study assessed levels of these proteins after MICR for benign indications. Methods: Blood samples were taken (n = 39) preoperatively (preop) and on postoperative days (POD) 1 and 3; in most cases a fourth sample was drawn between POD 7 and 30. sVEGFR1 and sVEGFR2 levels were measured via enzyme-linked immunosorbent assay (ELISA), which detects free and VEGF bound soluble receptor. Late samples were bundled into POD 7–13 and POD 14–30 time points. Results are reported as mean and standard deviation. The data was assessed with paired-samples t-test. Results: Preop, mean plasma sVEGFR2 level (9,203.7 ± 1,934.3 pg/ml) was significantly higher than the sVEGFR1 value (132.5 ± 126.2 pg/ml). sVEGFR2 levels were significantly lower on POD 1 (6,957.8 ± 1,947.7 pg/ml,) and POD 3 (7,085.6 ± 2,000.2 pg/ml), whereas sVEGFR1 levels were significantly higher on POD 1 (220.0 ± 132.8 pg/ml) and POD 3 (182.7 ± 102.1 pg/ml) versus preop results. No differences were found on POD 7–13 or 14–30. Conclusions: sVEGFR2 values decreased and sVEGFR1 levels increased early after MICR; due to its much higher baseline, the sVEGFR2 changes dominate. The net result is less VEGF bound to soluble receptor and more free plasma VEGF.

Abstract: Introduction: Plasma vascular endothelial growth factor (VEGF) levels are increased after surgery and may stimulate tumor growth after cancer resection. Angiopoietin 1 (Ang 1) and Ang 2 are proteins that impact VEGF-related angiogenesis (VRA). Ang 1 stabilizes mature vessels and inhibits VRA, whereas Ang 2 destabilizes vessels and promotes VRA. The ratio of Ang 1 to Ang 2 reflects the net effect; a low ratio promotes VRA. This study’s purpose was to determine the impact of open and minimally invasive (MIS) colorectal resection (CR) for benign indications on plasma Ang 1 and 2 levels. Methods: A total of 30 patients operated by MIS and 26 operated by open procedure were studied. Plasma was obtained preoperatively (PO) and on postoperative days (POD) 1 and 3. Plasma Ang 1 and Ang 2 levels were assessed via enzyme-linked immunosorbent assay (ELISA) in duplicate. Data were compared using Wilcoxon’s matched-pair test and the Mann–Whitney U-test (significance p < 0.05). Results: Indications, types of resection, and morbidity for the groups were similar. The mean MIS incision length was 4.7 ± 1.6 cm while it was 16.8 ± 7.1 cm for the open group (p = 0.0001). For both groups Ang 2 levels were significantly higher and the Ang 1 to Ang 2 ratio was significantly lower on POD 1 and 3 compared with preoperative results. Ang 1 levels were significantly decreased on POD 1 and 3 in the MIS group but only on POD 1 in the open group. For unclear reasons, preoperative Ang 1 levels and Ang 1 to Ang 2 ratios were significantly different between the groups, which precludes comparison of the postoperative results between groups. Conclusion: CR for benign pathology results in higher Ang 2 levels, lower Ang 1 levels, and lower Ang 1 to Ang 2 ratios early after surgery. These alterations are proangiogenic. These results, plus the already noted VEGF increases, suggest that surgery results in proangiogenic plasma protein changes that may stimulate tumor growth early after surgery. The duration of the Ang 1 and 2 changes needs to be determined.

Abstract: Background: Elevations of plasma vascular endothelial growth factor (VEGF) have been noted early after colorectal resection. The duration of this increase is unknown. Because VEGF is a potent promoter of angiogenesis, which is critical to tumor growth, a sustained increase in blood VEGF levels after surgery may stimulate the growth of residual metastases early after surgery. This preliminary study aimed to determine VEGF levels during the first month after colorectal resection. Methods: Patients from three prospective studies that had late postoperative blood samples available comprised the study population. Demographic, perioperative, pathologic, and complication data were collected. Plasma samples were obtained preoperatively for all patients: on postoperative day (POD) 1 for most patients and at varying time points thereafter during the first month after surgery and beyond. Levels of VEGF were determined via enzyme-linked immunoassay (ELISA) and compared using Wilcoxon’s matched pairs test. Because the numbers of specimens beyond POD 5 were limited, samples from 7-day time blocks were bundled and averaged to permit statistical analysis. Results: A total of 49 patients with cancer and 30 patients with benign indications, all of whom underwent minimally invasive colorectal resection, were assessed separately. With regard to the patients with cancer, the median preoperative plasma value was 150 pg/ml, and the peak postoperative median value for the POD 14 to 20 time block was 611.1 pg/ml. Furthermore, compared with the preoperative results, significant VEGF elevations were noted on POD 3 as well as during week 2 (POD 7–13), week 3 (POD 14–20), and week 4 (POD 21–27) (p < 0.05 for each). With regard to the benign patients, the median preoperative VEGF level was 112 pg/ml, and the peak postoperative value, 286 pg/ml, was noted during postoperative week 2. Significant elevations were noted on POD 3, and for weeks 2 and 3 as well as for POD 28 and later. Between 63% and 89% of the patients at each time point beyond POD 5 had elevated VEGF levels. Conclusion: This preliminary study demonstrates that after minimally invasive colorectal resection for cancer, median VEGF levels are significantly elevated on POD 3 and remain increased for as long as 4 weeks. Significant elevations in a similar pattern also were noted for the benign patients. However, the baseline and postoperative median values were lower. The clinical impact from increased blood levels of VEGF is uncertain. It is possible that the growth of residual tumor deposits may be stimulated early after surgery. These results warrant a larger study as well as endothelial cell in vitro assays to determine whether postoperative plasma stimulates proliferation and invasion.

Abstract: Background: Robotically assisted surgery offers the advantages of improved dexterity and elimination of tremor over conventional laparoscopic surgery. There have been few studies to date, however, examining the role of robotics in intestinal surgery. This study was undertaken to determine the feasibility and safety of using a robotic surgical system in the performance of intracorporeal small bowel strictureplasties in dogs. Methods: Using a robotic surgical system, a total of 16 strictureplasties were performed in the small bowel of eight dogs (two strictureplasties per dog). Using only intracorporeal robotic surgery, a 2.5 cm enterotomy was made longitudinally in the small bowel, and then closed in a Heineke-Mikulicz configuration with a one-layer running 3–0 braided absorbable suture (strictureplasty). All animals were allowed to survive for 7 days with prospective monitoring of bowel movements, level of activity, oral intake, and abdominal examination. After 7 days, necropsy was performed, examining all strictureplasty sites for signs of sepsis. The endpoints of the study were recovery of normal intestinal function (bowel movements), intraoperative and postoperative complications, and the appearance of the anastomoses at necropsy. Results: There was no intraoperative morbidity or mortality. All eight dogs survived 7 days and recovered well. All dogs had a bowel movement on the first postoperative day, and appeared healthy throughout the study period. Necropsy revealed that all 16 strictureplasty sites were healing without signs of sepsis. The median time per strictureplasty was 65 min (range, 45–110 min). One dog developed a superficial wound infection at a trocar site. Conclusions: A robotic surgical system can successfully be employed in the performance of intestinal strictureplasties in dogs. This study supports further investigation into the role of robotics in intestinal surgery in humans.

Background: The authors previously demonstrated a significant decrease in plasma levels of intact insulin-like growth factor binding protein-3 (IGFBP-3) after major open but not after laparoscopic-assisted surgery in humans. They postulated that this decrease may have an effect on postoperative tumor growth. It also has been shown that plasma levels of matrix metalloproteinase-9 (MMP-9), a protease capable of degrading IGFBP-3, are transiently increased after open colectomy in humans. The authors aimed to develop an animal model that would allow further study of the effect that surgical trauma has on plasma levels IGFBP-3 and MMP-9. In addition, they set out to assess the concentration of MMP-9 in circulating monocytes before and after surgery. Methods: The 30 mice included in this study were divided into three groups: sham laparotomy, carbon dioxide (CO2) pneumoperitoneum, and anesthesia control. All mice were IGFBP-3 transgenics (overexpressing human IGFBP-3) on a CD1 background. The mice were anesthetized using ketamine and xylazine. Blood was drawn retroorbitally 48 h before the procedure. The duration of the procedure was 30 min. The animals were killed 24 h postoperatively and blood was drawn. Intact IGFBP-3 levels were measured using a combination of Western blot analysis and enzyme-linked immunoassay (ELISA) at the two time points: before and after the operation. Plasma and peripheral blood mononuclear cell levels of MMP-9 were measured at each time point using zymography. Mononuclear cell lysates were used to determine intracellular MMP-9 levels. Results: Plasma levels of intact IGFBP-3 were significantly lower than preoperative levels after sham laparotomy. A mean decrease of 76.6% was noted (p&lt; 0.05). Zymography demonstrated significantly higher plasma MMP-9–related proteolytic activity than observed preoperatively after sham laparotomy (78.5 vs 42.3 Relative Units [RU]; p&lt; 0.05). In the pneumoperitoneum group, no significant decrease was found between the pre- and postoperative levels of intact IGFBP-3. A nonsignificant increase in MMP-9 was noted after CO2pneumoperitoneum (38 RU preoperatively vs. 46.4 RU postoperatively; p> 0.05). The anesthesia control group did not demonstrate a significant change in either circulating intact IGFBP-3 levels or MMP-9 levels. Mononuclear intracellular levels of MMP-9 were significantly lower after laparotomy than the preoperative levels (3 vs 37 RU). The postprocedure intracellular levels of MMP-9 were not significantly decreased in the pneumoperitoneum or anesthesia control group. Conclusion: Plasma levels of intact IGFBP-3, a cell growth regulating factor, were found to be decreased significantly after laparotomy. This decrease was not seen after pneumoperitoneum. Depletion of intact IGFBP-3 after laparotomy correlated with a rapid release of MMP-9 from mononuclear cells and an increase in circulating plasma MMP-9 levels. Matrix metalloproteinase-9 may play an important role in IGFBP-3 proteolysis after surgical trauma. Furthermore, circulating mononuclear cells are one source of MMP-9 after surgery. Finally, the model used reproduces events in humans after surgery, and thus should permit further study on the mechanism of IGFBP-3 proteolysis after surgical trauma.

The authors have previously demonstrated that insulin-like growth factor binding protein-3 (IGFBP-3) is depleted in plasma for 1 to 3 days after major open surgery (OS), but not after laparoscopic surgery (LS). After surgery, IGFP-3 cleavage occurs rapidly and is likely attributable to altered plasma proteolytic activity. This study aimed to assess plasma proteolysis after both open and closed colorectal resection and, if possible, to identify a protease/protease inhibitor system affected by surgery.Plasma from 88 patients with colorectal cancer (stages I–III) who underwent resection was obtained preoperatively (pre-OP) and on postoperative days (POD) 1 to 3. Plasma proteolytic activity was assessed via zymography. On the basis of the results, specific protease and protease inhibitor concentrations were next measured via enzyme-linked immunoassay (ELISA). Statistical analysis was performed using Wilcoxon’s test.Early after surgery, zymography showed a predominant band representing a 92-kDa gelatinase corresponding to a proform of matrix metalloproteinase-9 (MMP-9), a protease known to cleave IGFBP-3. In OS patients, the mean concentration of plasma MMP-9 was significantly higher on POD 1 than at pre-OP (p< 0.003). On POD 2 and 3, no differences were noted. In the LS group, the mean levels of MMP-9 before and after surgery were comparable. The levels of a natural MMP-9 inhibitor, tissue inhibitor of metalloproteinase-1 (TIMP-1), also were measured. In the OS group, the level of TIMP-1 was significantly higher on POD 1 (p< 0.0003) and POD 2 (p< 0.01) and 3 (p< 0.01) than at pre-OP. In the LS group, a smaller but significant increase in TIMP-1 levels was found between the pre-OP sample and the POD 1 (p< 0.01) and POD 2 (p< 0.01) samples. No difference was noted on POD 3 (p= 0.1).Open surgery, but not laparoscopic surgery, is accompanied by a short-lived significant increase in MMP-9 levels, which likely accounts for the decrease in IGFBP-3 levels observed after OS. The transitory nature of MMP-9 imbalance may be attributable to the increase in TIMP-1 levels postoperatively.

Abstract

Abstract

Background The European Association of Endoscopic Surgery (EAES) initiated a consensus development conference on the laparoscopic resection of colon cancer during the annual congress in Lisbon, Portugal, in June 2002. Methods A systematic review of the current literature was combined with the opinions, of experts in the field of colon cancer surgery to formulate evidence-based statements and recommendations on the laparoscopic resection of colon cancer. Results Advanced age, obesity, and previous abdominal operations are not considered absolute contraindications for laparoscopic colon cancer surgery. The most common cause for conversion is the presence of bulky or invasive tumors. Laparoscopic operation takes longer to perform than the open counterpart, but the outcome is similar in terms of specimen size and pathological examination. Immediate postoperative morbidity and mortality are comparable for laparoscopic and open colonic cancer surgery. The laparoscopically operated patients had less postoperative pain, better-preserved pulmonary function, earlier restoration of gastrointestinal function, and an earlier discharge from the hospital. The postoperative stress response is lower after laparoscopic colectomy. The incidence of port site metastases is <1%. Survival after laparoscopic resection of colon cancer appears to be at least equal to survival after open resection. The costs of laparoscopic surgery for colon cancer are higher than those for open surgery. Conclusion Laparoscopic resection of colon cancer is a safe and feasible procedure that improves short-term outcome. Results regarding the long-term survival of patients enrolled in large multicenter trials will determine its role in general surgery.

Background: It has been well established that open abdominal surgery results in systemic immunosuppression postoperatively; in contrast, laparoscopic surgery is associated with significantly better preserved systemic immune function. However, when intraperitoneal (local) immune function is considered, laparoscopic procedures done under a CO 2 pneumoperitoneum (pneumo) have been shown to result in greater immunosuppression compared to that of open surgery. Few studies have simultaneously assessed systemic and local immune function. The purpose of this study was to assess peripheral blood mononuclear cell (PBMC) and peritoneal macrophage tumor necrosis factor-α (TNF-α) levels, H 2O 2 production, and MHC class II antigen expression after open and laparoscopically assisted cecectomy in a rat model. Methods: A total of 75 Sprague Dawley rats were used for three separate experiments. For each study, rats were randomly divided into three groups: anesthesia alone (AC), laparoscopic-assisted cecectomy (LC), and open cecectomy via full laparotomy (OP). A CO 2 pneumo was used for laparoscopic operations. On postoperative day 1 the animals were sacrificed, macrophages were harvested via intraperitoneal lavage, and PBMCs were isolated from whole blood obtained by cardiac puncture. In experiment 1, macrophages and PBMC from each animal were stimulated with lipopolysaccharide, after which TNF-α levels of the supernatant were determined. In experiment 2, after stimulation with PMA, H 2O 2 release was assessed by measuring fluorescence. In experiment 3, via flow cytometry, the number of cells with surface MHC class II proteins were determined. Data from the three groups in each experiment were compared using analysis of variance Tukey-Kramer tests. Results: Macrophages and PBMC from mice in the OP group released significantly more TNF-α than cells from mice in the LC ( p < 0.05) or AC ( p < 0.05) groups. Macrophages from mice in the OP group released significantly less H 2O 2 than cells from the AC ( p < 0.01) and LC ( p < 0.05) groups. There was no difference between the AC and LC results. No significant differences in PBMC H 2O 2 release were noted among any of the groups. OP group macrophages expressed significantly less MHC class II antigen than did AC group macrophages ( p < 0.05). No differences were noted among the LC results and either the OP or AC group’s outcomes. No differences were noted in PBMC MHC class II expression among any of the groups. Conclusions: In all instances, the LC group’s macrophage results were similar to the AC group’s results. OC group macrophages produced significantly more TNF-α and less H 2O 2 than both the AC and LC groups. MHC class II protein expression was less for the OC group than for the AC group. OC group PBMCs produced more TNF-α. No differences in PBMC H 2O 2 release or MHC class II expression were noted. Laparoscopic methods better preserves the baseline values of the parameters studied.

There are few scientific reports documenting the effects of simulation training on learning. Issues of scientific validity challenge investigators who measure such outcomes. We perceived a failure of residents to change their technical management of oesophageal intubation after simulation training and sought clarification of this observation.

Background: We have previously shown that preoperative vaccination with the GA733 protein does not inhibit tumor growth in mice undergoing open surgery or carbon dioxide insufflation. In this study we assessed the antitumor effect of a combined GA733 and interleukin-12 (IL-12) vaccine. Methods: For this study, BALB/c mice were immunized with GA733, IL-12, or GA733 and IL-12, or they received no vaccine. Immediately after surgery (laparotomy or insufflation), GA733-transfected CT26 cells (C26-GA733) were injected subcutaneously into all mice. After 5 weeks, the mice were sacrificed, their tumors measured, GA733-specific antibodies determined by enzyme-linked immunoassay, and GA-733-specific cytotoxicity tested by flow cytometry using labeled C26-GA733 cells. Results: Tumors were significantly ( p < 0.05) smaller in both the insufflation and open groups that received combined GA733 and IL-12 than in their respective control subjects. Vaccination also induced a significant increase in the antibody and cell-mediated tumor-specific immunity. Conclusion: A preoperative vaccine consisting of GA733 and IL-12 inhibited postoperative tumor growth after open and closed surgery and allowed the mice to overcome the immunosuppressive effects of surgery.

Background: Efficient killing of tumor cells depends on T cells that migrate from the circulation to the peripheral tissues; these cells express CD31. This study was undertaken to determine the impact of open (OS) and laparoscopic (LS) colorectal surgery on the percentage of circulating CD3 +CD31 + cells. Methods: Peripheral blood was collected from 27 OS and 24 LS colon cancer patients preoperatively (preOP) and on postoperative days 1 (POD1) and 3 (POD3). CD31 + T cells were assessed by flow cytometry using monoclonal antibodies. Results: In the OS group, the percentage of CD3 +CD31 + cells was significantly lower in POD1 and POD3 samples compared to the preOP results. LS surgery did not result in a significant change in the percentage of these T cells. A significant correlation was found between the decrease in the percentage of CD3 +CD31 + cells and the length of incision in OS patients. Conclusions: The percentage of CD3 +CD31 + cells decreases following OS but not LS and may be related to incision length. This may compromise T cell function in the peripheral tissues in the postoperative period.

The integrins have an ability to interact with extracellular matrix proteins to confer adhesive and motile properties on cells. The means by which these activities operate and the manner in which they are integrated with cell functions is of particular relevance to many biological processes. In the present paper, the developing understanding of the bi-directional relationship between the protein kinase C family of signal transducers and integrins is discussed.

Whole autologous colon cancer vaccines in combination with various adjuvants have been used in both animals and humans. At this writing, vaccine regimens have been initiated in humans 3 to 6 weeks postoperatively. This delay between tumor resection and vaccination gives surviving tumor cells an opportunity to establish themselves. Vaccine administered either preoperatively or immediately after surgery, in theory, should be more effective. However, surgery-related immunosuppression may diminish the effectiveness of preoperative or early postoperative vaccines. This problem may be overcome by limiting postoperative immunosuppression via the use of minimally invasive methods. Alternatively, the impact of the vaccine may be improved by encapsulating the vaccine, plus adjuvant, which in theory, should extend exposure time. Encapsulation of cancer vaccines in polysaccharide particles has not yet been studied. The goal of this study was to determine whether vaccine encapsulation, preoperative vaccination, and early postoperative vaccination affected the tumor burden. In addition, laparotomy and carbon dioxide insufflation were compared. Vaccine was prepared from ultraviolet-irradiated C26 colon cancer cells in combination with monophosphoryl lipid A, either in suspension or entrapped in alginate beads. The C26 cell line and syngeneic BALB/c mice were used for all the studies. Tumor volumes were determined after excision of the tumors 2 weeks after inoculation in these studies. Encapsulated vaccine was more effective than the standard liquid vaccine. Significantly smaller tumors were noted in mice receiving encapsulated vaccine than in either the control group (p<0.01) or the liquid vaccine group (p<0.05). The use of a preoperative encapsulated vaccine was associated with significantly smaller tumors after laparotomy, pneumoperitoneum, or anesthesia alone when the tumors were established immediately after surgery. With an already established tumor, encapsulated vaccine, when given in the early postoperative period to mice that had undergone laparotomy or anesthesia alone was associated with significantly smaller tumors that those found in control animals. The incorporation of a whole-cell vaccine and monophosphoryl lipid A into alginate beads increases the efficacy of pre-operative and early postoperative tumor vaccines in the setting of both laparotomy and Carbon dioxide pneumoperitoneum. The use of perioperative vaccines may prove to be an effective way to immunize patients with cancer undergoing surgery.

Abstract An artificial soil mix made out of industry wastes and sewage sludge has been created for the revegetation of an industrial site. Physico-chemical properties were measured over time to examine soil formation in a chronosequence of 11 gardens aged 3–11 years, and in a 3-year longitudinal study of 8 replicate experimental plots. In the field plots, available nutrient content was initially high but declined quickly in 3 months. Particle weathering occurred, with an increase in the finer soil fractions after 1 year. pH was initially 7.62 and declined to 6.85 by 3 years. Native tree growth was exceptionally good over the 2 years monitored, with average trunk diameter increases of 144 mm for Corymbia maculata, 94 mm for Acacia floribunda, and 39 mm for Callistemon salignus. In the chronosequence study, there was a build- up of nutrients (C, N, and P) in the soil mix over 6–10 years, with a slight decrease by 11 years. This study has shown that soil development has occurred in the short and longer terms, with rapid changes seen in the first 12 months. High levels of N and P remaining after 11 years, and abundant organic C for microbial decomposition, indicate the potential for nutrient cycling soil genesis, particle weathering, carbon, nitrogen.

OBJECTIVE: To test our hypothesis that tumors would be more easily established and grow more aggressively after laparotomy than after laparoscopy. This hypothesis was based on studies that have demonstrated that surgery can suppress immune function and facilitate tumor growth and that have shown preservation of immune function after laparoscopic procedures. DESIGN: Double-blinded, randomized, control trial. SETTING: Research laboratory and animal care facility. ANIMALS: One hundred forty 5- to 6-week-old C3H/He female mice. INTERVENTIONS: Three experiments with three groups each: laparotomy, insufflation, and anesthesia controls. All animals received an intradermal inoculation of tumor cells in the dorsal skin. The anesthesia control cohort underwent no procedure. The laparotomy cohort underwent a midline laparotomy from the xiphoid process to the pubis, which was closed after 30 minutes. The insufflation cohort underwent peritoneal insufflation with carbon dioxide for 30 minutes. MAIN OUTCOME MEASURES: Tumor volume, tumor mass, and incidence of tumor establishment. RESULTS: In the first experiment, the tumor volumes of the anesthesia control and insufflation groups followed a similar pattern of plateau and regression. The tumor volumes of the laparotomy group followed a different pattern and were significantly larger than those of the control and insufflation groups on postoperative days 6 and 12 (P&lt;.05 for all comparisons). In the second experiment, tumors in the laparotomy group were approximately three times larger than those of the control group (P&lt;.01) and almost twice as large as insufflation group tumors (P&lt;.01) by mass. In the third experiment, there was a significantly higher incidence of tumor establishment in the laparotomy group than in the insufflation (P&lt;.04) or control (P&lt;.01) groups. The incidence was not different between the control and insufflation groups. CONCLUSIONS: Tumors were more easily established and grew more aggressively after laparotomy than after insufflation. These results, coupled with those that demonstrate an immune advantage to laparoscopy over laparotomy, suggest that the difference in observed tumor growth may be related to immune function. While much work remains to be done, we believe these data provide evidence of a previously undemonstrated benefit of laparoscopic intervention.(Arch Surg. 1995;130:649-653)

IN response to the low level of non-smoking pro vision in public catering establishments in Greater Nottingham, a campaign was launched to encourage the implementation of no-smoking policies, with an information pack sent by post to 356 establishments. Managers were encouraged to order action packs, which included free no-smoking display materials, and to register their establishments in a public guide to no-smoking restaurants. A certificate was awarded by the Department of Public Health to those making over 50 per cent non-smoking provision. The response rate to the campaign was 10.1 per cent after the first mail-out, rising to 14.8 per cent after the second mail-out, and achieving a total of 25.2 per cent after telephone contact had been made. While the campaign was a valuable initial exercise, this work should be continued by environmental health officers who visit catering establishments in the course of their normal duties.

PURPOSE: This study was undertaken to investigate the ability of a high-pressure CO2 environment to aerosolize tumor cells in bothin vitroandin vivo models. (An aerosol is defined as a stable gaseous suspension of insoluble particles.) Also, this study was designed to determine if rapid desufflation is capable of transporting fluid laden with tumor cells. METHODS: The fourin vitro aerosol experiments were performed in an 18.9-l plastic vessel fitted with two 7-mm ports and a compliant latex balloon affixed to the top. After CO2 insufflation, the vessel was desufflated through a sterile soluset containing 25 ml of culture media that was subsequently emptied into a culture dish, incubated for two weeks, and periodicallyassessed for growth. At the bottom of the vessel, one of the following was placed: Study 1 and 2, a suspension of B16 melanoma or colon 26 tumor cells in liquid culture media; Study 3, colon 26 cells in saline solution; Study 4, several pieces of solid colon 26 tumor. In Studies 1 to 3, cell preparations were subjected to the following high-pressure CO2 conditions (pneumo): 1) static pneumo of 15 and 30 mmHg (10 minute dwell); 2) a continuous flow (CF) of CO2 (10 l) while maintaining a pressure of 15 or 30 mmHg in the vessel. In Study 4, only the 30 mmHg static and CF conditions were tested. Between 6 and 12 determinations were performed for each condition and cell preparation.In vivo aerosol experiments consisted of Spraque Dawley rats that received intraperitoneal injections of 10-5 B16 cells in 0.1 ml of liquid media.Two laparoscopic ports were placed in the abdomen, one each for insufflation and desufflation. Study groups were: 1, static CO2 pneumo of 15 mmHg; 2 and 3, continuous CO2 flow (10 l) at a stable pneumo pressure of 5 and 10 mmHg. Desufflation was performedvia the same collecting device and handled in an identical manner to thein vitroexperiments described above. Thein vitro balloon experiment was designed to investigate the ability of desufflation to transport fluid-containing tumor cells; latex balloon model was used. To prevent complete loss of volume on desufflation, a wire coil was placed inside the balloon. Twenty ml of media containing 20×10−6B16 cells was placed in the bottom of the balloon. The balloon was insufflated with 1 to 21 of gas. There were three study groups that differed in the degree to which the cell suspension was agitated before desufflation. Study conditions were as follows: 1) no agitation; 2) moderate agitation to coat the lower walls and coil; 3) maximum agitation to coat the entire balloon. To verify the viability of tumor cells,at the end of eachin vitroandin vivo study, a sample of tumor cells or peritoneal washing was incubated in sterile media. These samples served as positive controls. RESULTS:In vitro aerosol studies consisted of the following. At the end of two weeks of incubation, no tumor growth was noted in any of the 124 test dishes. The 14 control samples all demonstrated tumor growth.In vivo aerosol studies consisted of the following. Zero of 18 experimental dishes grew tumor. All three peritoneal washing samples demonstrated growth.In vitro balloon studies consisted of the following. Zero of 12 test dishes in Groups 1 and 2 demonstrated growth, whereas five of six dishes did so in Group 3 (maximally agitated before desufflation). Again, positive controls all grew tumor cells. SUMMARY: We were unable to demonstrate aerosol formation in any of thein vitroandin vivo studies performed. In the balloon experiment, desufflation-related transport of tumor cells was demonstrated but only when the entire balloon surface was coated with the tumor cell suspension before desufflation. CONCLUSION: Aerosols of tumor cells are not likely to form. Free intraperitoneal tumor cells are most likely found in liquid suspension. Desufflation is a potential means of transport of cell-laden fluid.

AbstractLong-term canopy storage of seeds in fruits (bradyspory) varies among species and is thought to be related to the fire regime experienced by the plant community. This study sought to quantify intraspecific variation in bradyspory among nine populations of Banksia serrata(Proteaceae) on the south coast of New South Wales. Marked differences were found between populations, ranging from more than 30% of follicles open at two coastal sites, to less than 5% of follicles open at two inland heath sites. Low levels of bradyspory occurred particularly in coastal sites which also had Banksia integrifolia, a non-bradysporous species, present. In addition to spontaneous follicle opening without fire, fall of infructes-cences to the ground after breaking of branches was observed to be a major contributor to seed release. At three sites where fire had not occurred for many years, the amount of seedling establishment since the last fire corresponded well with levels of bradyspory; there were no inter-fire recruits at the site with the strongest bradyspory, while at the site with the weakest bradyspory there were numerous inter-fire plants, some with lignotubers large enough to be able to tolerate the next fire. It is argued that populations of B. serrataexhibit variable patterns of recruitment, depending on the site characteristics, ranging from complete dependence on fire for population maintenance to bet-hedging (spreading potential recruitment between fire events and inter-fire periods). Variations in populations and reproductive characteristics among sites make the application of demographic models to management decisions habitat-specific.

We have used three continuous human neuroblastoma cell lines to establish patterns of in vitro drug sensitivities, as judged by clonogenic assay. We evaluated 12 ‘standard’ antitumor drugs already in clinical usage, and tested four newer analogues, one of cisplatin and three of doxorubicin, and the investigational agent desferrioxamine. A certain heterogeneity of drug sensitivities was noted amongst these three cell lines, but a few general conclusions can be drawn. Responses of all lines tested were similar for actinomycin D, dibromodulcitol, doxorubicin, 5-fluorouracil, melphalan and VM 26. However, line CHP100 proved hypersensitive to amsacrine, bleomycin, methotrexate and vincristine yet refractory to cisplatin, carboplatin and VP-16, compared with the other two lines. This emphasizes the necessity for using a panel of cell lines for this type of drug screening programme. A comparison of IC50 drug concentrations, derived from these in vitro tests, with plasma levels achievable clinically, indicate that VP-16, VM 26, doxorubicin and cisplatin appear to be the most effective agents in this tumor type. This finding is consistent with clinical experience. The newer doxorubicin analogues proved 2–5 fold more cytotoxic than doxorubicin itself. However, these differences also appear to be reflected in the lower dose ranges now being tested in phase I/II clinical trials.

We have used a series of drug resistant continuous tumour cell lines of murine, hamster or human origin, to screen in vitro for new drugs effective at overcoming resistance expressed to clinically useful antitumour drugs. We have established that spirogermanium appears to express a unique lack of cross resistance to a wide range of ‘standard’ antitumour drugs including 5-fluorouracil, cisplatin, methotrexate, vincristine and adriamycin, as judged by its equivalent effectiveness in reducing survival, measured by clonogenic assays, of the parental and drug-resistant sublines following 24 hour in vitro treatments. Spirogermanium was also able to overcome the multidrug resistance exhibited by the colchicine-resistant mutant CHRC5 cells and a subline of vincristine-resistant MCF-7 human breast carcinoma cells, following 1 or 24 hour drug treatments. These preclinical studies suggest that this novel compound may prove a potentially useful agent for inclusion in ‘non-cross-resistant drug combinations’.

Protein kinase C signaling is desensitized through a combination of dephosphorylation and proteolysis in intact cells. The process of dephosphorylation is analyzed here, as well as its relationship to degradation. It is established for protein kinase Calpha that dephosphorylation occurs in a membrane compartment following activation and temporally preceding significant degradation. The phosphatase responsible for the dephosphorylation appears to be a heterotrimeric type 2A phosphatase, which is shown to be in part constitutively membrane associated. Consistent with a role for this activity, okadaic acid is shown to inhibit the phorbol ester-induced dephosphorylation of protein kinase C that occurs in intact cells. Furthermore, phorbol ester-induced down-regulation of protein kinase Calpha is shown not to be dependent on the rate of dephosphorylation, indicating that these desensitizing pathways may operate in parallel.

Stimulation of the murine macrophage RAW 264.7 cell line with phorbol esters fails to promote nitric oxide synthesis as occurs in rat hepatocytes or peritoneal macrophages. Transfection of RAW 264.7 cells with plasmids harboring protein kinase C (PKC) -epsilon isotype but not with PKC-alpha, -beta1, -delta, or constitutively active -alpha and -beta1 isotypes resulted in the expression of nitric oxide synthase type II (iNOS), as reflected by the synthesis of nitric oxide measured in the culture medium of transfected cells. cotransfection of RAW 264.7 cells with the -1592 to +121-base pair promoter region of the murine iNOS gene and PKC isotypes specifically induced the transactivation of this promoter in the case of the plasmids containing the PKC-epsilon isotype. The mechanism by which PKC-epsilon induced iNOS expression involved the activation of nuclear factor binding to kappaB sites (NF-kappaB) as deduced by the suppressive effect of pyrrolidine dithiocarbamate on nitric oxide synthesis, an inhibitor of NF-kappaB activation, and by the activation of kappaB sites in cells transfected with a vector containing a kappaB motif linked to a chloramphenicol acetyltransferase reporter gene. These results suggest that PKC-epsilon can regulate a pathway that promotes iNOS expression in macrophages in response to phorbol ester activation.

Summary: When logarithmically growing neuroblastoma cells were exposed in vitro for 24 hr to a range of concentrations of various antitumour drugs and then cloned in agar to assess colony-forming ability, the dose-response curves obtained were of two types only, namely exponential—plateau or exponential. The former category, included hydroxyurea, 1,1′-propylene bispiperazine-3,5-dione (ICRF-159), vincristine and vindesine, where the plateau was reached before 1 log cell kill, and 4′-demethylepipodophllotoxin thenylidine glucoside (NSC 122819) (VM-26) and 4′-demethyl-epipodophllotoxin-9-(4,6-oethylidine-β-D-glucopyranoside (NSC 141540) (VP-16-213), where the plateau occurred at approximately 5% survival. Exponential survival curves were obtained with actinomycin D, Adriamycin, bleomycin, cis-dichlorodiammine platinum (II) (cis-platinum), dibromodulcitol, 5-fluorouracil, 4′-(9-acridiny-lamino)methanesulfon-m-anisidine (NSC 249992) (mAMSA), melphalan, and peptichemio. A comparison of drug concentrations required to reduce survival in vitro by 70%, with a 24-hr drug exposure, was attempted with those concentrations achievable as plasma levels in man after conventional drug therapy. The results obtained, after many and varied assumptions, allowed the division of the drugs tested into three main groups: (1) most effective agents, including mAMSA, VM-26, and Adriamycin; (2) agents with some activity—vincristine, vindesine, VP-16-213, cis-platinum, melphalan, and peptichemio, although only when the latter three drugs were used at the higher dosage levels; (3) agents with little, if any, activity—actinomycin D, bleomycin, dibromodulcitol, 5-fluorouracil, hydroxyurea, and ICRF-159. In terms of attempting clinical correlations, available data suggest definite value in treating neuroblastoma with VM-26 and Adriamycin [from our group (1)] and also with vincristine, melphalan (high dose), peptichemio, and cis-platinum [from our group (2)]. No significant clinical activity has been reported for actinomycin D nor for bleomycin in previously treated children, and both these drugs proved negative in this model test system. Among the newer agents tested experimentally, our results suggest that although clinical evaluation of mAMSA, VP-16-213, and vindesine might be profitable, dibromodulcitol and ICRF-159 may prove inactive.Speculation: The dismal prognosis for the majority of children with neuroblastoma serves to highlight the need for new and more effective therapies. One approach is to attempt to screen experimentally in vitro for drugs effective in this disease. Our preliminary studies, using only one cell line derived from one portion of a human tumour, have suggested, with many reservations, some correlations between in vitro and clinical data. This work is now being extended to consider other human neuroblastoma cell lines and to monitor retrospectively drug responses in vitro with clinical responses. These studies are essential before any attempts are made to extrapolate any of the in vitro results to humans.

A series of continuous human tumour cell lines, derived from various tumour types, were used to establish whether the combination of spirogermanium (SP) with other ‘standard’ antitumour drugs proved superior to these as single agents in reducing cell survival in vitro. A non-cytotoxic concentration of SP was selected and when combined with a range of concentrations of cisplatin or 5-fluorouracil (5-FU), definite synergistic cell kill was noted in all lines tested. In contrast, the combination of SP with various other antitumor drugs, including adriamycin, methotrexate and the vinca alkaloids and with X-irradiation did not enhance cytotoxicity.

Wildfires are a typical event in many Australian plant communities. Vesicular-arbuscular mycorrhizal (VAM) fungi are important for plant growth in many communities, especially on infertile soils, yet few studies have examined the impact of wildfire on the infectivity of VAM fungi. This study took the opportunity offered by a wildfire to compare the infectivity and abundance of spores of VAM fungi from: (i) pre-fire and post-fire sites, and (ii) post-fire burned and unburned sites. Pre-fire samples had been taken in May 1990 and mid-December 1990 as part of another study. A wildfire of moderate intensity burned the site in late December 1990. Post-fire samples were taken from burned and unburned areas immediately after the fire and 6 months after the fire. A bioassay was used to examine the infectivity of VAM fungi. The post-fire soil produced significantly less VAM infection than the pre-fire soil. However, no difference was observed between colonization of plant roots by VAM fungi in soil taken from post-fire burned and adjacent unburned plots. Soil samples taken 6 months after the fire produced significantly more VAM than corresponding soil samples taken one year earlier. Spore numbers were quantified be wet-sieving and decanting of 100-g, air-dried soil subsamples and microscopic examination. For the most abundant spore type, spore numbers were significantly lower immediately post-fire. However, no significant difference in spore numbers was observed between post-fire burned and unburned plots. Six months after the fire, spore numbers were the same as the corresponding samples taken 1 year earlier. All plants appearing in the burned site resprouted from underground organs. All post-fire plant species recorded to have mycorrhizal associations before the fire had the same associations after the fire, except for species of Conospermum (Proteaceae), which lacked internal vesicles in cortical cells in the post-fire samples.