Treating acute diverticulitis in pre- and post-solid-organ transplant patients: a single-institution cohort study.

AIM: Immunosuppressed patients are more likely to fail nonoperative management of acute diverticulitis and have more postoperative complications than the immunocompetent. Transplant recipients form a subcategory among the immunosuppressed with unique challenges. The aim of this work is to report 30-day postoperative complications after colectomy for acute diverticulitis and success rates of nonoperative management in pre- and post-transplant patients. METHOD: This is a retrospective cohort study at a single-institution tertiary referral centre. Patients with a history of acute diverticulitis were extracted from a database of 6152 recipients of solid-organ abdominal transplant between 2000 and 2015 and stratified by the index episode of diverticulitis: before or after solid-organ transplant surgery. Outcomes included 30-day postoperative complications and failure of nonoperative management. RESULTS: Acute diverticulitis occurred in 93 patients, 69 (74%) posttransplant. Postcolectomy complications were higher posttransplant than pretransplant (43% vs. 13%, p = 0.04). Posttransplant status was not an independent risk factor for complications (odds ratio 3.59, 95% CI 0.79-16.31) when adjusting for sex and surgical acuity. Immediate urgent colectomy (29% vs. 31%, p = 0.84) and failure of nonoperative management (7% vs. 9%, p = 0.82) were similar. Complications occurred equally in those requiring urgent colectomy after nonoperative management and those undergoing immediate urgent colectomy. CONCLUSION: Urgent colectomy rates are similar in solid-organ abdominal transplant recipients pre- and posttransplant. Posttransplant complication rates appear to be increased but transplant status as an independent factor is not significantly associated with an increased risk in this study cohort. These findings should be considered when counselling patients on the relative risks and benefits of surgical intervention for diverticulitis before versus after solid-organ transplantation.

Venous thromboembolism prophylaxis following colorectal surgery: a survey of American Society of Colon and Rectal Surgery (ASCRS) member surgeons.

BACKGROUND: Postoperative venous thromboembolism (VTE) is associated with significant morbidity. Evidence from other surgical specialties demonstrate inadequate use of extended VTE prophylaxis following cancer surgery. While guidelines recommend extended VTE prophylaxis for patients undergoing surgery for colorectal cancer (CRC), it is unknown to what extent colon and rectal surgeons adhere to these recommendations. METHODS: An 18-question online survey was distributed to all surgeon members of the American Society of Colon and Rectal Surgeons (ASCRS). The survey was designed to capture knowledge, attitudes, and practices regarding ASCRS VTE prevention guidelines. Questions were also designed to elucidate barriers to adopting these guidelines. RESULTS: The survey was distributed to 2,316 ASCRS-member surgeons and there were 201 complete responses (8.7% response rate). Most respondents (136/201, 68%) reported that they were familiar with ASCRS VTE prevention guidelines and used them to guide their practice. Extended VTE prophylaxis was reported to be routinely prescribed by the majority of surgeons following CRC resection (109/201, 54%), with an additional 27% reporting selective prescribing (55/201). The most frequently reported reasons for not prescribing extended VTE chemoprophylaxis following CRC resection included patient compliance and insurance/copay issues. CONCLUSION: Most ASCRS-member surgeon respondents reported that they are familiar with ASCRS VTE prevention guidelines, though only 54% surgeons reported routinely prescribing extended VTE prophylaxis following CRC surgery. Patient compliance and insurance issues were identified as the most common barriers. Targeted interventions at the surgeon, patient, and payer level are required to increase the use of extended VTE prophylaxis following CRC resection.

Prolonged thromboprophylaxis with low molecular weight heparin for abdominal or pelvic surgery.

BACKGROUND: This an update of the review first published in 2009.Major abdominal and pelvic surgery carries a high risk of venous thromboembolism (VTE). The efficacy of thromboprophylaxis with low molecular weight heparin (LMWH) administered during the in-hospital period is well-documented, but the optimal duration of prophylaxis after surgery remains controversial. Some studies suggest that patients undergoing major abdominopelvic surgery benefit from prolongation of the prophylaxis up to 28 days after surgery. OBJECTIVES: To evaluate the efficacy and safety of prolonged thromboprophylaxis with LMWH for at least 14 days after abdominal or pelvic surgery compared with thromboprophylaxis administered during the in-hospital period only in preventing late onset VTE. SEARCH METHODS: We performed electronic searches on 28 October 2017 in the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, LILACS and registered trials (Clinicaltrials.gov October 28, 2017 and World Health Organization International Clinical Trials Registry Platform (ICTRP) 28 October 2017). Abstract books from major congresses addressing thromboembolism were handsearched from 1976 to 28 October 2017, as were reference lists from relevant studies. SELECTION CRITERIA: We assessed randomized controlled clinical trials (RCTs) comparing prolonged thromboprophylaxis (≥ fourteen days) with any LMWH agent with placebo, or other methods, or both to thromboprophylaxis during the admission period only. The population consisted of persons undergoing abdominal or pelvic surgery for both benign and malignant pathology. The outcome measures included VTE (deep venous thrombosis (DVT) or pulmonary embolism (PE)) as assessed by objective means (venography, ultrasonography, pulmonary ventilation/perfusion scintigraphy, spiral computed tomography (CT) scan or autopsy). We excluded studies exclusively reporting on clinical diagnosis of VTE without objective confirmation. DATA COLLECTION AND ANALYSIS: Review authors identified studies and extracted data. Outcomes were VTE (DVT or PE) assessed by objective means. Safety outcomes were defined as bleeding complications and mortality within three months after surgery. Sensitivity analyses were also performed with unpublished studies excluded, and with study participants limited to those undergoing solely open and not laparoscopic surgery. We used a fixed-effect model for analysis. MAIN RESULTS: We identified seven RCTs (1728 participants) evaluating prolonged thromboprophylaxis with LMWH compared with control or placebo. The searches resulted in 1632 studies, of which we excluded 1528. One hundred and four abstracts, eligible for inclusion, were assessed of which seven studies met the inclusion criteria.For the primary outcome, the incidence of overall VTE after major abdominal or pelvic surgery was 13.2% in the control group compared to 5.3% in the patients receiving out-of-hospital LMWH (Mantel Haentzel (M-H) odds ratio (OR) 0.38, 95% confidence interval (CI) 0.26 to 0.54; I2 = 28%; moderate-quality evidence).For the secondary outcome of all DVT, seven studies, n = 1728, showed prolonged thromboprophylaxis with LMWH to be associated with a statistically significant reduction in the incidence of all DVT (M-H OR 0.39, 95% CI 0.27 to 0.55; I2 = 28%; moderate-quality evidence).We found a similar reduction when analysis was limited to incidence in proximal DVT (M-H OR 0.22, 95% CI 0.10 to 0.47; I2 = 0%; moderate-quality evidence).The incidence of symptomatic VTE was also reduced from 1.0% in the control group to 0.1% in patients receiving prolonged thromboprophylaxis, which approached significance (M-H OR 0.30, 95% CI 0.08 to 1.11; I2 = 0%; moderate-quality evidence).No difference in the incidence of bleeding between the control and LMWH group was found, 2.8% and 3.4%, respectively (M-H OR 1.10, 95% CI 0.67 to 1.81; I2 = 0%; moderate-quality evidence).No difference in mortality between the control and LMWH group was found, 3.8% and 3.9%, respectively (M-H OR 1.15, 95% CI 0.72 to 1.84; moderate-quality evidence).Estimates of heterogeneity ranged between 0% and 28% depending on the analysis, suggesting low or unimportant heterogeneity. AUTHORS' CONCLUSIONS: Prolonged thromboprophylaxis with LMWH significantly reduces the risk of VTE compared to thromboprophylaxis during hospital admittance only, without increasing bleeding complications or mortality after major abdominal or pelvic surgery. This finding also holds true for DVT alone, and for both proximal and symptomatic DVT. The quality of the evidence is moderate and provides moderate support for routine use of prolonged thromboprophylaxis. Given the low heterogeneity between studies and the consistent and moderate evidence of a decrease in risk for VTE, our findings suggest that additional studies may help refine the degree of risk reduction but would be unlikely to significantly influence these findings. This updated review provides additional evidence and supports the previous results reported in the 2009 review.

Prolonged thromboprophylaxis with low molecular weight heparin for abdominal or pelvic surgery.

BACKGROUND: This an update of the review first published in 2009.Major abdominal and pelvic surgery carries a high risk of venous thromboembolism (VTE). The efficacy of thromboprophylaxis with low molecular weight heparin (LMWH) administered during the in-hospital period is well-documented, but the optimal duration of prophylaxis after surgery remains controversial. Some studies suggest that patients undergoing major abdominopelvic surgery benefit from prolongation of the prophylaxis up to 28 days after surgery. OBJECTIVES: To evaluate the efficacy and safety of prolonged thromboprophylaxis with LMWH for at least 14 days after abdominal or pelvic surgery compared with thromboprophylaxis administered during the in-hospital period only in preventing late onset VTE. SEARCH METHODS: We performed electronic searches on 28 October 2017 in the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, LILACS and registered trials (Clinicaltrials.gov October 28, 2017 and World Health Organization International Clinical Trials Registry Platform (ICTRP) 28 October 2017). Abstract books from major congresses addressing thromboembolism were handsearched from 1976 to 28 October 2017, as were reference lists from relevant studies. SELECTION CRITERIA: We assessed randomized controlled clinical trials (RCTs) comparing prolonged thromboprophylaxis (≥ fourteen days) with any LMWH agent with placebo, or other methods, or both to thromboprophylaxis during the admission period only. The population consisted of persons undergoing abdominal or pelvic surgery for both benign and malignant pathology. The outcome measures included VTE (deep venous thrombosis (DVT) or pulmonary embolism (PE)) as assessed by objective means (venography, ultrasonography, pulmonary ventilation/perfusion scintigraphy, spiral computed tomography (CT) scan or autopsy). We excluded studies exclusively reporting on clinical diagnosis of VTE without objective confirmation. DATA COLLECTION AND ANALYSIS: Review authors identified studies and extracted data. Outcomes were VTE (DVT or PE) assessed by objective means. Safety outcomes were defined as bleeding complications and mortality within three months after surgery. Sensitivity analyses were also performed with unpublished studies excluded, and with study participants limited to those undergoing solely open and not laparoscopic surgery. We used a fixed-effect model for analysis. MAIN RESULTS: We identified seven RCTs (1728 participants) evaluating prolonged thromboprophylaxis with LMWH compared with control or placebo. The searches resulted in 1632 studies, of which we excluded 1528. One hundred and four abstracts, eligible for inclusion, were assessed of which seven studies met the inclusion criteria.For the primary outcome, the incidence of overall VTE after major abdominal or pelvic surgery was 13.2% in the control group compared to 5.3% in the patients receiving out-of-hospital LMWH (Mantel Haentzel (M-H) odds ratio (OR) 0.38, 95% confidence interval (CI) 0.26 to 0.54; I2 = 28%; moderate-quality evidence).For the secondary outcome of all DVT, seven studies, n = 1728, showed prolonged thromboprophylaxis with LMWH to be associated with a statistically significant reduction in the incidence of all DVT (M-H OR 0.39, 95% CI 0.27 to 0.55; I2 = 28%; moderate-quality evidence).We found a similar reduction when analysis was limited to incidence in proximal DVT (M-H OR 0.22, 95% CI 0.10 to 0.47; I2 = 0%; moderate-quality evidence).The incidence of symptomatic VTE was also reduced from 1.0% in the control group to 0.1% in patients receiving prolonged thromboprophylaxis (M-H OR 0.30, 95% CI 0.08 to 1.11; I2 = 0%; moderate-quality evidence).No difference in the incidence of bleeding between the control and LMWH group was found, 2.8% and 3.4%, respectively (M-H OR 1.10, 95% CI 0.67 to 1.81; I2 = 0%; moderate-quality evidence).No difference in mortality between the control and LMWH group was found, 3.8% and 3.9%, respectively (M-H OR 1.15, 95% CI 0.72 to 1.84; moderate-quality evidence).Estimates of heterogeneity ranged between 0% and 28% depending on the analysis, suggesting low or unimportant heterogeneity. AUTHORS' CONCLUSIONS: Prolonged thromboprophylaxis with LMWH significantly reduces the risk of VTE compared to thromboprophylaxis during hospital admittance only, without increasing bleeding complications or mortality after major abdominal or pelvic surgery. This finding also holds true for DVT alone, and for both proximal and symptomatic DVT. The quality of the evidence is moderate and provides moderate support for routine use of prolonged thromboprophylaxis. Given the low heterogeneity between studies and the consistent and moderate evidence of a decrease in risk for VTE, our findings suggest that additional studies may help refine the degree of risk reduction but would be unlikely to significantly influence these findings. This updated review provides additional evidence and supports the previous results reported in the 2009 review.

Prolonged thromboprophylaxis with low molecular weight heparin for abdominal or pelvic surgery.

BACKGROUND: This an update of the review first published in 2009.Major abdominal and pelvic surgery carries a high risk of venous thromboembolism (VTE). The efficacy of thromboprophylaxis with low molecular weight heparin (LMWH) administered during the in-hospital period is well-documented, but the optimal duration of prophylaxis after surgery remains controversial. Some studies suggest that patients undergoing major abdominopelvic surgery benefit from prolongation of the prophylaxis up to 28 days after surgery. OBJECTIVES: To evaluate the efficacy and safety of prolonged thromboprophylaxis with LMWH for at least 14 days after abdominal or pelvic surgery compared with thromboprophylaxis administered during the in-hospital period only in preventing late onset VTE. SEARCH METHODS: We performed electronic searches on 28 October 2017 in the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, LILACS and registered trials (Clinicaltrials.gov October 28, 2017 and World Health Organization International Clinical Trials Registry Platform (ICTRP) 28 October 2017). Abstract books from major congresses addressing thromboembolism were handsearched from 1976 to 28 October 2017, as were reference lists from relevant studies. SELECTION CRITERIA: We assessed randomized controlled clinical trials (RCTs) comparing prolonged thromboprophylaxis (≥ fourteen days) with any LMWH agent with placebo, or other methods, or both to thromboprophylaxis during the admission period only. The population consisted of persons undergoing abdominal or pelvic surgery for both benign and malignant pathology. The outcome measures included VTE (deep venous thrombosis (DVT) or pulmonary embolism (PE)) as assessed by objective means (venography, ultrasonography, pulmonary ventilation/perfusion scintigraphy, spiral computed tomography (CT) scan or autopsy). We excluded studies exclusively reporting on clinical diagnosis of VTE without objective confirmation. DATA COLLECTION AND ANALYSIS: Review authors identified studies and extracted data. Outcomes were VTE (DVT or PE) assessed by objective means. Safety outcomes were defined as bleeding complications within three months after surgery. Sensitivity analyses were also performed with unpublished studies excluded, and with study participants limited to those undergoing solely open and not laparoscopic surgery. We used a fixed-effect model for analysis. MAIN RESULTS: We identified seven RCTs (1728 participants) evaluating prolonged thromboprophylaxis with LMWH compared with control or placebo. The searches resulted in 1632 studies, of which we excluded 1528. One hundred and four abstracts, eligible for inclusion, were assessed of which seven studies met the inclusion criteria.For the primary outcome, the incidence of overall VTE after major abdominal or pelvic surgery was 13.2% in the control group compared to 5.3% in the patients receiving out-of-hospital LMWH (Mantel Haentzel (M-H) odds ratio (OR) 0.38, 95% confidence interval (CI) 0.26 to 0.54; I2 = 28%; seven studies, n = 1728; moderate-quality evidence).For the secondary outcome of all DVT, seven studies, n = 1728, showed prolonged thromboprophylaxis with LMWH to be associated with a statistically significant reduction in the incidence of all DVT (M-H OR 0.39, 95% CI 0.27 to 0.55; I2 = 28%; moderate-quality evidence).We found a similar reduction when analysis was limited to incidence in proximal DVT (M-H OR 0.22, 95% CI 0.10 to 0.47; I2 = 0%; moderate-quality evidence).The incidence of symptomatic VTE was also reduced from 1.0% in the control group to 0.1% in patients receiving prolonged thromboprophylaxis (M-H OR 0.30, 95% CI 0.08 to 1.11; I2 = 0%; moderate-quality evidence).No difference in the incidence of bleeding between the control and LMWH group was found, 2.8% and 3.4%, respectively (HM-H OR 1.10, 95% CI 0.67 to 1.81; I2 = 0%; seven studies, n = 2239; moderate-quality evidence).Estimates of heterogeneity ranged between 0% and 28% depending on the analysis, suggesting low or unimportant heterogeneity. AUTHORS' CONCLUSIONS: Prolonged thromboprophylaxis with LMWH significantly reduces the risk of VTE compared to thromboprophylaxis during hospital admittance only, without increasing bleeding complications after major abdominal or pelvic surgery. This finding also holds true for DVT alone, and for both proximal and symptomatic DVT. The quality of the evidence is moderate and provides moderate support for routine use of prolonged thromboprophylaxis. Given the low heterogeneity between studies and the consistent and moderate evidence of a decrease in risk for VTE, our findings suggest that additional studies may help refine the degree of risk reduction but would be unlikely to significantly influence these findings. This updated review provides additional evidence and supports the previous results reported in the 2009 review.

Outcomes and efficacy of magnetic resonance imaging-compatible sacral nerve stimulator for management of fecal incontinence: A multi-institutional study.

BACKGROUND: Fecal incontinence (FI) is an involuntary passage of fecal matter which can have a significant impact on a patient's quality of life. Many modalities of treatment exist for FI. Sacral nerve stimulation is a well-established treatment for FI. Given the increased need of magnetic resonance imaging (MRI) for diagnostics, the InterStim which was previously used in sacral nerve stimulation was limited by MRI incompatibility. Medtronic MRI-compatible InterStim was approved by the United States Food and Drug Administration in August 2020 and has been widely used. AIM: To evaluate the efficacy, outcomes and complications of the MRI-compatible InterStim. METHODS: Data of patients who underwent MRI-compatible Medtronic InterStim placement at UPMC Williamsport, University of Minnesota, Advocate Lutheran General Hospital, and University of Wisconsin-Madison was pooled and analyzed. Patient demographics, clinical features, surgical techniques, complications, and outcomes were analyzed. Strengthening the Reporting of Observational studies in Epidemiology(STROBE) cross-sectional reporting guidelines were used. RESULTS: Seventy-three patients had the InterStim implanted. The mean age was 63.29 ± 12.2 years. Fifty-seven (78.1%) patients were females and forty-two (57.5%) patients had diabetes. In addition to incontinence, overlapping symptoms included diarrhea (23.3%), fecal urgency (58.9%), and urinary incontinence (28.8%). Fifteen (20.5%) patients underwent Peripheral Nerve Evaluation before proceeding to definite implant placement. Thirty-two (43.8%) patients underwent rechargeable InterStim placement. Three (4.1%) patients needed removal of the implant. Migration of the external lead connection was observed in 7 (9.6%) patients after the stage I procedure. The explanation for one patient was due to infection. Seven (9.6%) patients had other complications like nerve pain, hematoma, infection, lead fracture, and bleeding. The mean follow-up was 6.62 ± 3.5 mo. Sixty-eight (93.2%) patients reported significant improvement of symptoms on follow-up evaluation. CONCLUSION: This study shows promising results with significant symptom improvement, good efficacy and good patient outcomes with low complication rates while using MRI compatible InterStim for FI. Further long-term follow-up and future studies with a larger patient population is recommended.

Feasibility and Safety of Intraoperative Colonoscopy after Segmental Colectomy and Primary Anastomosis.

Patients presenting with near-obstructing colon lesions requiring segmental colectomy may benefit from intraoperative colonoscopy (IOC) after primary anastomosis for a more timely and accurate diagnosis of synchronous lesions. The aim of this study is to demonstrate the feasibility and safety of this technique. A retrospective cohort study of patients undergoing single-stage segmental colectomy and anastomosis at a single tertiary care institution from 2011 to 2013 was performed. One Hundred and sixty-eight consecutive patients underwent segmental colectomy and primary anastomosis of which 78 (46%) were unable to receive preoperative colonoscopy (POC) because of near-obstructing lesions and received IOC after the anastomosis. IOC detected synchronous adenomatous polyps in 24.4 per cent, diverticular disease in 19 per cent, and colitis/proctitis in 2.5 per cent. The IOC group was not significantly different from the POC group with regard to overall morbidity (31% vs 39% P = 0.45), anastomotic leakage (1.3% vs 0%, P = 0.46), or wound infection (5.1% vs 1.1%, P = 0.18). Operation time was 19 minutes longer in the intraoperative group, but overall length of hospital stay was not significantly different (6.4 ± 2.9 days vs 7.3 ± 4.6 days). In patients unable to receive POC because of partial obstruction, IOC after primary anastomosis is both feasible and safe for detecting proximal synchronous lesions.

Feasibility and Benefit of Incorporating a Multimedia Cadaver Laboratory Training Program into a Didactics Curriculum for Junior and Senior Surgical Residents.

OBJECTIVE: As operative experience in general surgery decreases and work hour limitations increase there is less exposure of surgical residents to advanced vascular and trauma exposures. Many institutions have demonstrated benefits of cadaver laboratory courses. We have incorporated a multimedia cadaver laboratory course into our general surgery residency didactics curriculum with the objective to demonstrate a benefit of the program as well as the feasibility of incorporation. STUDY DESIGN: This is a prospective study at a tertiary care institution including general surgery residents within our residency program. A curriculum was designed, requiring residents to complete multimedia learning modules before both a trauma cadaver laboratory and vascular exposure cadaver laboratory. Outcome measures included self-efficacy/confidence (precourse and postcourse 5-point Likert surveys), knowledge (net performance on precourse and postcourse multiple choice examinations), and resident perception of the curriculum (postcourse 5-point Likert survey). Data were analyzed using ANOVA paired t-tests. RESULTS: For the vascular cadaver laboratory, resident knowledge improved overall from an average of 41.2% to 50.0% of questions correct (p = 0.032) and self-efficacy/confidence improved by 0.59 from 1.52 to 2.11 out of 5 (p = 0.009). Median confidence is 1.37 out of 5 and 2.32 out of 5, before and after course, respectively. Wilcoxon nonparametric test reveals a p = 0.011. Resident's perception of the usefulness of the laboratory evaluation was 3.85 out 5. There were 85.71% agreed that the laboratory is useful and 14.29% were disagree. The Z-score is -0.1579 (means 0.1579 standard deviations a score of 3.85 below the benchmark). The percentile rank is 56.27%. The coefficient of variation is 24.68%. For the trauma cadaver laboratory, resident knowledge improved overall from an average of 55.89% to 66.17% of questions correct (p = 0.001) and self-efficacy/confidence improved by 0.75 from 1.68 out of 5 to 2.43 out of 5 (p = 0.011). Median confidence level is 1.41 out of 5 before the training course and 2.64 out of 5 after the training course. Wilcoxon signed rank test gives a p value of 0.008. Resident's perception of the usefulness of the laboratory evaluation was 3.94 out 5. There were 72.22% agreed that the laboratory is useful and 27.78% were neutral. The Z-score is -0.098 (means 0.098 standard deviations a score of 3.94 below the benchmark). The percentile rank is 53.90%. The coefficient of variation is 15.48%. CONCLUSIONS: Incorporating a multimedia cadaver laboratory into a residency education didactics curriculum was both feasible and beneficial for resident education. We demonstrate an improvement in knowledge and self efficacy/confidence following both cadaver laboratory courses.

Leadership in the NHS leading at all levels.

STOKE MANDEVILLE Hospital NHS Trust in Aylesbury, Buckinghamshire, is a district general hospital with a busy maternity unit delivering around 2,700 babies a year.

Nephrolithiasis in "back-to-back" kidneys.

A 57-year-old woman presented with a 1-week history of left lower quadrant pain and nausea and vomiting. Computed tomography without contrast demonstrated a left 2.3-cm calculus at the ureteropelvic junction and a 6-mm lower pole calculus. The kidneys were in the pelvis and oriented "back-to-back," with the lateral portions of the kidneys fused in the midline. To our knowledge, this is the first description of this renal fusion anomaly. The patient underwent robotic pyelolithotomy of the ureteropelvic junction calculus and subsequent flexible ureteroscopic laser lithotripsy of the lower pole calculus and ureteral stent placement through the assistant working port.

Complex dielectric properties of microcrystalline cellulose, anhydrous lactose, and α-lactose monohydrate powders using a microwave-based open-reflection resonator sensor.

The real (ε') and imaginary (ε″) components of the complex permittivity of anhydrous lactose and microcrystalline cellulose (MCC) under different bulk densities, moisture contents (MCs), and times of hydration (for anhydrous lactose) were measured nondestructively using a microwave resonator sensor operating in the range of 700-800 MHz. Measurements of sensor resonant frequency and conductance allow, through calibration, determination of the complex dielectric properties ε' (relative permittivity) and ε″ (relative dielectric loss) of the test material. Characteristic graphs of ε″ versus ε' - 1 curve for each powder were generated as a function of bulk density and MC. Such data can be used to develop empirical models for the simultaneous in situ measurement of the bulk density and MC of the powders. Unlike MCC, anhydrous lactose is converted to its hydrate form in the presence of moisture, which causes a reduction in the amount of physisorbed and "free" water and a subsequent change in the dielectric properties. For powders such as anhydrous lactose that can form a crystal hydrate in the presence of moisture, a combination of techniques such as vibrational spectroscopy together with microwave resonator measurements are appropriate to characterize, in situ, the physical and chemical properties of the powder.

A novel mouse model for segmental orthotopic colon cancer.

Spontaneous colon tumor mouse strains offer numerous advantages in modeling disease. However, the wide temporal window in which lesions form and the stochastic nature of lesion location require larger cohorts for assessment of disease modulation. Reliable, reproducible and inexpensive mouse models of early-stage and invasive cancer would add to existing transgenic models. We show a new method for the creation of orthotopic murine tumors centered in the mucosal and submucosal layers anywhere in the colon, allowing creation of lesions of known age, location and extent. The system overcomes the disadvantages of heterotopic implantation and allows evaluation of lesions distally in the colon as well as proximally, thereby providing an additional method to study the effects of regionality. Invasion, host vascularization and application to disparate cell lines are demonstrated. Noninvasive imaging with magnetic resonance and colonoscopy, allowed in part by the tumor location, show potential applications of this approach.