Influence of floating plant density on potential herbicide spray loss.

BACKGROUND: Mesocosm experiments were conducted to evaluate the effect of floating plant density on over-the-top spray solution loss to the column using a tracer dye. Experiments quantified in-water rhodamine water tracer (RWT) dye concentration after foliar treatment at 935 L ha-1 to waterhyacinth [Eichhornia crassipes (Mart.) Solms], waterlettuce (Pistia stratiotes L.) and giant salvinia (Salvinia molesta D.S. Mitchell) at 0, 25, 50 and 100% area covered (PAC). RESULTS: As expected, spray loss to the water surface decreased with increasing plant density in all species. However, each species exhibited an unique relationship between density and percentage spray loss. The plant material required to result in 50% spray loss (ED50 ) was 32, 62 and 55 PAC for waterhyacinth, waterlettuce and giant salvinia, respectively. Greater ED50 estimates in waterlettuce and giant salvinia were attributed to plant architecture and leaf orientation compared to waterhyacinth, which grows more vertically and has a greater overall surface area to intercept and retain spray solution. However, when treated at 100 PAC, waterhyacinth and waterlettuce resulted in 20-25% spray loss, whereas giant salvinia resulted in only 10% loss. Consequently, giant salvinia exhibited a near 1:1 relationship between spray loss and PAC (slope = -0.93). CONCLUSION: These data suggest that potential herbicide spray loss, as affected by plant density, is largely species-specific and dependent on leaf morphology and plant architecture. Further research will confirm these findings under field conditions as well as to identify other parameters that might affect spray loss when treating floating and emergent plants. © 2021 Society of Chemical Industry. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

Effect of Dynamic Workstation Use on Radiologist Detection of Pulmonary Nodules on CT.

PURPOSE: The aim of this study was to determine the effects of using a treadmill workstation during CT interpretation on radiologists' sensitivity for lung nodule detection, accuracy and adherence to accepted management recommendations, and examination interpretation time. METHODS: This HIPAA-compliant study was approved by the institutional review board. Three radiologists performed a retrospective review of 55 CT examinations of the chest originally performed for lung cancer screening. These studies were reviewed both while sitting at a conventional workstation and while walking at a treadmill workstation. A separate thoracic radiologist reviewed the examinations at a conventional workstation only to serve as a control. The number of pulmonary nodules detected, accuracy of or adherence to follow-up recommendations, and time required for examination interpretation were recorded and compared between each condition. RESULTS: There was no statistically significant difference in the total number of nodules detected while walking versus seated. Intraobserver follow-up recommendations were consistent to highly consistent between sitting and walking. There was moderate interobserver agreement between the radiologists' recommendation for seated versus walking conditions. There was a statistically significant difference in time taken to complete each examination, with interpretation during walking taking less time than during sitting. CONCLUSIONS: Use of a treadmill workstation does not significantly affect the detection of lung nodules on CT or lead to changes in management recommendations but does decrease examination interpretation time.

Surveillance Imaging in Patients With Endometrial Cancer in First Remission.

OBJECTIVE: The clinical benefit of surveillance imaging in endometrial cancer remains undefined. This retrospective study was conducted to evaluate the positive predictive value (PPV) of surveillance imaging in endometrial cancer. METHODS: A total of 128 patients in first remission after treatment for endometrial cancer (uterine papillary serous, clear cell, stage III endometroid) who had surveillance imaging were retrospectively identified. The surveillance period was defined from the time of first-negative scan after treatment to the time when treatment was started for recurrent disease. Reports of surveillance scans were reviewed for the presence or absence of findings. The primary outcome was PPV of surveillance imaging. Cost and radiation exposure from surveillance imaging were also evaluated. RESULTS: A total of 128 patients had 707 surveillance scans (computed tomography, positron emission tomography-computed tomography with 2-deoxy-2-[18F]fluoro-d-glucose, magnetic resonance image, and bone scans). Median follow-up was 54 months (range: 9-173). Of all, 47 patients (37%) started therapy for recurrent endometrial cancer at the discretion of the treating physician. PPV of all surveillance imaging was 57.7%. Per patient, the mean number of surveillance scans was 5.6 (range: 2-21). The mean cost of imaging was $4200 (range: $1200-$18,700) and mean radiation exposure was 109.6mSV (range: 16-445mSv). CONCLUSIONS: Surveillance imaging detected a significant number of recurrences in patients with high-risk endometrial cancer at a reasonable cost related to the overall risk. Well-designed prospective imaging trials are warranted to assess the clinical benefit of surveillance imaging.

Urothelial lesion formation is mediated by TNFR1 during neurogenic cystitis.

Interstitial cystitis (IC) is a chronic bladder inflammatory disease of unknown etiology that shares similarities with Crohn's disease and psoriasis. IC, often regarded as a neurogenic cystitis, is associated with urothelial lesions that likely compromise the bladder permeability barrier and thereby contribute to patient morbidity. Here, we use a murine model of neurogenic cystitis to investigate the mechanism of urothelial lesion formation and find that urothelial apoptosis induces formation of lesions. Lesions formed in wild-type mice but not in mice deficient in TNF, TNF receptors, or mast cells. In urothelial cultures, only siRNAs targeting TNFR1, but not TNFR2, blocked TNF-induced apoptosis, indicating a primary role for TNFR1. Trans-epithelial resistance, a measure of bladder barrier function, decreased during neurogenic cystitis in wild-type and TNFR2(-/-) mice but was stabilized in TNF(-/-) mice. Anti-TNF antibodies both altered bladder mast cell localization and stabilized barrier function. Based on these findings, we conclude that mast cell activation and release of TNF drive urothelial apoptosis and lesion formation in a murine neurogenic cystitis model, and we hypothesize that anti-TNF therapy may stabilize bladder barrier function in IC patients.

Induction of the urothelial differentiation program in the absence of stromal cues.

PURPOSE: The urothelial stroma is presumed to have a critical role in the formation and homeostasis of normal urothelium. To determine the intrinsic capacity of urothelial cells to initiate urothelial differentiation human urothelial cell were cultured under conditions that promote differentiation in the absence of stromal signaling. MATERIALS AND METHODS: Immortalized and primary human urothelial cells were cultured in semisolid medium. Recovered cells were then analyzed by immunofluorescence, flow cytometry and immunoblotting for expression of the differentiation specific keratins K18 and K8, and cyclin-cyclin-dependent kinase inhibitors. The expression of these markers in cells following semisolid culture was then compared with that in normal bladder and ureteral mucosa as well as in synthetic urothelium generated by 3-dimensional organotypic raft cultures. RESULTS: Organotypic raft culture of primary and immortalized urothelial cells generated full-thickness epithelium that resembled human bladder and ureteral urothelium, and expressed K8 and K18 in superficial layers. Suspension culture in semisolid medium induced K18 expression approximately 9-fold at 24 hours. p21 and p27 expression were induced by 6 hours and yet p21 expression subsided within 12 hours, while p27 expression persisted. CONCLUSIONS: These results indicate that primary and immortalized human urothelial cells have the capacity to enter the urothelial differentiation program and such entry does not require inductive signals from stroma. Furthermore, these data suggest that p21 and p27 have distinct roles in regulating the urothelial cell cycle.

Epithelial differentiation promotes the adherence of type 1-piliated Escherichia coli to human vaginal cells.

Colonization of the vaginal introitus by fecal Escherichia coli is thought to be a key initial event leading to acute urinary tract infection, yet the mannosylated receptor for type 1 pili on the squamous epithelium of vaginal mucosa is unknown. E. coli expressing type 1 pili adhered to sections of normal human vaginal epithelium in a gradient with greatest binding in upper cell layers was observed, which suggests that epithelial differentiation influences bacterial binding. Consistent with this observation, bacterial binding was enhanced in vaginal epithelial cultures that were induced to differentiate, and this enhanced bacterial binding was associated with increased K13 expression levels and increased binding of the mannose-specific lectin Galanthus nivalis agglutinin. These results demonstrate that the binding of type 1-piliated E. coli to vaginal epithelial cells correlates with epithelial differentiation and suggest that the vaginal receptor for type 1 pili is up-regulated during differentiation.