89 research outputs found

    Estimation of Agricultural Production Relations in the LUC Model for China

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    Chinas demand for feed-grains has been growing fast during the last two decades, largely due to the increasing meat demand. This raises the important question whether China will in the coming years be able to satisfy these increasing needs which has implications that reach far beyond the country itself, especially in the light of Chinas upcoming accession to WTO. The answer depends on many factors, including the policy orientation of the Chinese government, the loss of cropland caused by the ongoing industrialization and urbanization processes, and the effect of climate change on the agricultural potentials of the country. To analyze these issues, the Land Use Change (LUC) Project is engaged in the development of an intertemporal welfare maximizing policy analysis model. The present report presents the input-output relationships for agricultural crops in this model. The specified relationships are geographically explicit and determine the crop output combinations that can be achieved, under the prevailing biophysical conditions across China, from given input combinations in each of some 2040 counties, on the basis of data for 1990. The inputs are chemical and organic fertilizer, labor and machinery. Irrigated and rain-fed land is distinguished as separate land-use types. Distinct relationships are estimated by cross-section for eight economic regions distinguished in the LUC model. The biophysical potential enters as an asymptote in a generalized Mitscherlich-Baule (MB) yield function and is computed on the basis of an agro-ecological assessment of climatic and land resources, including irrigation. The chosen form globally satisfies the required slope and curvature conditions. Estimation results show that all key parameters are significant and are of the expected sign. The calculated elasticities of aggregate output with respect to inputs reflect rather closely the relative scarcity of irrigated land, labor and other inputs across the different regions. It also appears that if account is taken of the distance to main urban centers, the observed cropping patterns are generally consistent with profit maximization. Confirmation is found for the often noted labor surplus in the Southern and South-Eastern regions

    The Influence of Pregnancy on the Recurrence of Cutaneous Malignant Melanoma in Women

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    Objective. The aim of this study was to determine whether pregnancy increases the recurrence risk of cutaneous malignant melanoma (CMM) in women with a history of stage I CMM. Methods. The electronic medical databases of Medline and Embase were explored. All 1084 obtained articles were screened on title and abstract using predetermined inclusion and exclusion criteria. A critical appraisal of relevance and validity was conducted on the remaining full text available articles. Results. Two studies were selected. Both studies revealed no significant difference in disease-free survival between women with stage I CMM and the control population. Conclusion. Pregnancy does not increase the recurrence risk of CMM in women with a history of stage I CMM

    Management of non-visualization following dynamic sentinel lymph node biopsy for squamous cell carcinoma of the penis

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    Objectives: To review the management and clinical outcomes of uni- or bilateral non-visualization of inguinal lymph nodes during dynamic sentinel lymph node biopsy (DSNB) in patients diagnosed with penile cancer and clinically impalpable inguinal lymph nodes (cN0), and to develop an algorithm for the management of patients in which non-visualization occurs. Patients and Methods: This is a retrospective observational study over a period of 4 years, comprising 166 patients with penile squamous cell carcinoma undergoing DSNB and followed up for a minimum of 6 months. All cases diagnosed with uni- or bilateral non-visualization of sentinel nodes in this cohort were identified from a penile cancer database. The management of the inguinal lymph nodes after non-visualization and the oncological outcomes including local and regional recurrence rates were documented. Results: Out of 166 consecutive patients undergoing DSNB, 20 patients (12%) had unilateral non-visualization after injection of intradermal 99mTc. Of these 20 patients, seven underwent repeat DSNB at a later date, with six having successful visualization. One patient had persistent non-visualization and proceeded to a superficial modified inguinal lymphadenectomy (SML). None of these patients experienced recurrence at follow-up. A further seven patients underwent modified SML with on-table frozen-section analysis of the lymph node packet; none of these patients were found to have micrometastatic disease in the inguinal lymph nodes, although one patient developed metastatic inguinal node disease at a later date. Six patients elected to undergo clinical surveillance and have remained disease-free. Conclusion: Patients with impalpable inguinal lymph nodes undergoing DSNB with ≥G2 T1 disease should ideally have bilateral visualization of the sentinel lymph nodes, reflecting the drainage pattern from the primary tumour. In the present series, 12% of patients were found to have unilateral non-visualization after DSNB. Among patients offered a repeat DSNB at a later date, localizing the sentinel node was successful in 86% of cases. Patients with favourable histological characteristics can be placed on clinical surveillance. Those with high-risk disease can be offered a repeat DSNB procedure on the proviso that SML may be carried out if there is repeated non-visualization. Larger cohorts are required to validate this proposed algorithm

    Clinicopathologic predictors of finding additional inguinal lymph node metastases in penile cancer patients following positive dynamic sentinel node biopsy:a European multicentre evaluation

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    OBJECTIVES: Following tumour positive sentinel lymph node biopsy (+DSNB), completion inguinal lymph node dissection (ILND) is negative in 84-89% of basins. Thus, ILND after +DSNB may be considered overtreatment resulting in substantial morbidity. This study aimed to develop a predictive model for additional inguinal lymph node metastases (LNM) at ILND following +DSNB using DSNB characteristics to identify a patient group in which ILND might be omitted. PATIENTS AND METHODS: A retrospective study of 407 inguinal basins with a +DSNB of penile cancer patients who underwent subsequent ILND from seven European centres. From the histopathology reports, the number of positive and negative lymph nodes, extranodal extension and size of the metastasis were recorded. Using bootstrapped logistic regression, variables were selected for the clinical prediction model based on the optimisation of Akaike's information criterion. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was calculated for the resulting model. Decision curve analysis (DCA) was used to evaluate the clinical utility of the model. RESULTS: 64 (16%) of +DSNB harboured additional LNM at ILND. The number of positive nodes at +DSNB (odds ratio (OR) 2.19; 95% confidence interval (CI) 1.17-4.00; p=0.01) and the largest metastasis size in mm (OR 1.06; 95%CI 1.03-1.10; p=0.001) were selected for the clinical prediction model. The AUC was 0.67 (95%CI 0.60-0.74). The DCA showed no clinical benefit of using the clinical prediction model. CONCLUSION: A small but clinically important group of basins harbour additional LNM at completion ILND following +DSNB. While DSNB characteristics were associated with additional LNM, they did not improve the selection of basins in which ILND could be omitted. Thus, completion ILND remains necessary in all basins with a +DSNB

    Driving pressure during general anesthesia for open abdominal surgery (DESIGNATION) : study protocol of a randomized clinical trial

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    Background Intraoperative driving pressure (Delta P) is associated with development of postoperative pulmonary complications (PPC). When tidal volume (V-T) is kept constant, Delta P may change according to positive end-expiratory pressure (PEEP)-induced changes in lung aeration. Delta P may decrease if PEEP leads to a recruitment of collapsed lung tissue but will increase if PEEP mainly causes pulmonary overdistension. This study tests the hypothesis that individualized high PEEP, when compared to fixed low PEEP, protects against PPC in patients undergoing open abdominal surgery. Methods The "Driving prESsure durIng GeNeral AnesThesIa for Open abdomiNal surgery trial" (DESIGNATION) is an international, multicenter, two-group, double-blind randomized clinical superiority trial. A total of 1468 patients will be randomly assigned to one of the two intraoperative ventilation strategies. Investigators screen patients aged >= 18 years and with a body mass index <= 40 kg/m(2), scheduled for open abdominal surgery and at risk for PPC. Patients either receive an intraoperative ventilation strategy with individualized high PEEP with recruitment maneuvers (RM) ("individualized high PEEP") or one in which PEEP of 5 cm H2O without RM is used ("low PEEP"). In the "individualized high PEEP" group, PEEP is set at the level at which Delta P is lowest. In both groups of the trial, V-T is kept at 8 mL/kg predicted body weight. The primary endpoint is the occurrence of PPC, recorded as a collapsed composite of adverse pulmonary events. Discussion DESIGNATION will be the first randomized clinical trial that is adequately powered to compare the effects of individualized high PEEP with RM versus fixed low PEEP without RM on the occurrence of PPC after open abdominal surgery. The results of DESIGNATION will support anesthesiologists in their decisions regarding PEEP settings during open abdominal surgery

    Intratunical Injection of Human Adipose Tissue–Derived Stem Cells Restores Collagen III/I Ratio in a Rat Model of Chronic Peyronie’s Disease

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    INTRODUCTION: Previous studies have shown that the injection of adipose tissue–derived stem cells (ADSCs) into the tunica albuginea (TA) during the active phase of Peyronie’s disease (PD) prevents the development of fibrosis. AIM: To investigate, using an animal model, whether local injection of human ADSCs (hADSCs) can alter the degree of fibrosis in the chronic phase of PD. METHODS: 27 male, 12-week-old rats were divided into 3 equal groups: sham, PD without treatment, and PD treated with hADSCs 1 month after disease induction. Sham rats underwent 2 injections of vehicle into the TA 1 month apart. PD rats underwent transforming growth factor β1 (TGFβ1) injection and injection of vehicle 1 month later. PD-hADSC rats underwent TGFβ1 injection followed by 1 million hADSCs 1 month later. 1 week after treatment, n = 3 animals/group were euthanized, and the penises were harvested for quantitative polymerase chain reaction. 1 month after treatment, the other animals, n = 6 per group, underwent measurement of intracavernous pressure (ICP) and mean arterial pressure (MAP) during electrostimulation of the cavernous nerve. After euthanasia, penises were again harvested for histology and Western blot. MAIN OUTCOME MEASURE: The primary outcome measures included (a) gene expression at one week post-injection; (b) measurement of ICP/MAP upon cavernous nerve stimulation as a measure of erectile function; (c) elastin, collagen I and III protein expression; and (d) Histomorphometric analysis of the penis. Means where compared by analysis of variance (ANOVA) followed by a Student-Newman-Keuls test for post hoc comparisons or Mann-Whitney test when applicable. RESULTS: No significant difference was noted in ICP or ICP/MAP in response to cavernous nerve electrostimulation between the 3 groups at 2.5, 5, and 7.5 V (P > .05 for all voltages). PD animals developed tunical and subtunical areas of fibrosis with a significant upregulation of collagen III protein. The collagen III/I ratio was higher in the PD (4.6 ± 0.92) group compared with sham (0.66 ± 0.18) and PD-hADSC (0.86 ± 0.06) groups (P < .05) These fibrotic changes were prevented when treated with hADSCs. Compared with PD rats, PD-hADSC rats demonstrated a decreased expression of several fibrosis-related genes. CONCLUSION: Injection of hADSCs reduces collagen III expression in a rat model of chronic PD

    What Is the Most Effective Management of the Primary Tumor in Men with Invasive Penile Cancer: A Systematic Review of the Available Treatment Options and Their Outcomes.

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    CONTEXT: The primary lesion in penile cancer is managed by surgery or radiation. Surgical options include penile-sparing surgery, amputative surgery, laser excision, and Moh's micrographic surgery. Radiation is applied as external beam radiotherapy (EBRT) and brachytherapy. The treatment aims to completely remove the primary lesion and preserve a sufficient functional penile stump. OBJECTIVE: To assess whether the 5-yr recurrence-free rate and other outcomes, such as sexual function, quality of life, urination, and penile preserving length, vary between various treatment options. EVIDENCE ACQUISITION: The EMBASE, MEDLINE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials (CENTRAL; Cochrane HTA, DARE, HEED), Google Scholar, and ClinicalTrials.gov were searched for publications from 1990 through May 2021. Randomized controlled trials, nonrandomized comparative studies (NRCSs), and case series (CSs) were included. EVIDENCE SYNTHESIS: The systematic review included 88 studies, involving 9578 men from 16 NRCSs and 72 CSs. The cumulative mean 5-yr recurrence-free rates were 82.0% for penile-sparing surgery, 83.9% for amputative surgery, 78.6% for brachytherapy, 55.2% for EBRT, 69.4% for lasers, and 88.2% for Moh's micrographic surgery, as reported from CSs, and 76.7% for penile-sparing surgery and 93.3% for amputative surgery, as reported from NRCSs. Penile surgery affects sexual function, but amputative surgery causes more appearance concerns. After brachytherapy, 25% of patients reported sexual dysfunction. Both penile-sparing surgery and amputative surgery affect all aspects of psychosocial well-being. CONCLUSIONS: Despite the poor quality of evidence, data suggest that penile-sparing surgery is not inferior to amputative surgery in terms of recurrence rates in selected patients. Based on the available information, however, broadly applicable recommendations cannot be made; appropriate patient selection accounts for the relative success of all the available methods. PATIENT SUMMARY: We reviewed the evidence of various techniques to treat penile tumor and assessed their effectiveness in oncologic control and their functional outcomes. Penile-sparing as well as amputative surgery is an effective treatment option, but amputative surgery has a negative impact on sexual function. Penile-sparing surgery and radiotherapy are associated with a higher risk of local recurrence, but preserve sexual function and quality of life better. Laser and Moh's micrographic surgery could be used for smaller lesions
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