Quaternary IPM (integrated pest management)--concept for the control of powdery mildew in sugar beets.

Powdery mildew, caused by Erysiphe betae (Vanha) Weltzien, may be assumed as an important leaf disease in sugar beet growing areas of central Europe. Although the causal agent is mainly adapted to arid climatic zones, the disease is appearing every year, where the extent of infection is mainly dependent on weather conditions and susceptibility of cultivar. The losses caused by powdery mildew seldom exceed 10% of sugar yield; moreover, losses are likely only under the condition that the epidemic onset occurs before end-August. Nevertheless, the epidemic onset varies in a wide range, as there are years with high incidence followed by growing periods without severe infection. Therefore, in order to have a flexible control of the disease, where the use of fungicides could be minimised to an essential amount, a quaternary IPM (Integrated Pest Management) -concept was developed. The development is based on epidemiological field studies (Germany, 1993-2004, n = 76) of sugar beet leaf diseases under variation of year, site and cultivar. Efficacy of fungicide treatment timing was assessed in relation to the epidemic development. Comparison of treatments comprised fungicide sprays carried out from disease initiation till later stages of the epidemic. Additionally, the assessments were performed in relation to an untreated and a healthy control--the latter was three times treated according to a treatment regime with three to four week intervals. The effect of different application timings was measured by the potential of disease and yield loss control. The quaternary concept combines the advantages of four elements in order to compensate the constraints of the single tools: The period without disease risk is determined by a so-called negative-prognosis (i). First symptoms appear in the period from mid-July till the beginning of September. If disease initiation cannot be excluded, field observations by a sample of 100 leaves are advised. The disease scores enable the appliance of action thresholds (ii). The latter are defined as early stages of the epidemic in order to optimize the efficiency of fungicide treatments. For an initial treatment a threshold of 5% infected leaves is defined. However, incidence in the height of action thresholds is not affecting an instant damage. The stage when a sugar beet is damaged effectively is rather defined by the economic damage threshold (iii). As a consequence, because exceeding of action threshold doesn't implicate immediate yield risk, loss prediction (iv) is required. The loss prediction assesses the likelihood of disease progress will exceed the economic damage threshold at harvest time. Loss risk is existent in case of action threshold exceeding till mid-August if cultivar susceptibility is low respectively end-August if susceptibility is high.

Factors affecting the onset of cercospora leaf spot epidemics in sugar beet and establishment of disease-monitoring thresholds.

ABSTRACT Severe Cercospora leaf spots epidemics in sugar beet during the late 1980s and early 1990s in southern Germany prompted us to initiate investigations on the epidemiology of the causal agent, Cercospora beticola. The data set involved 69 field trials (1993 to 2003) focusing on factors affecting the epidemic onset of this disease. Observations were made at weekly intervals, recording the calendar week when canopy closure occurred (growth stage according to BBCH scale = 39) and symptom development by assessing the percentage of infected leaf area on a single-leaf basis (n = 40 plants). These monitoring trials revealed that epidemic onset varied between early July and mid-September. Hence, the target was to identify the reasons for this variation in order to deduct the most suitable approach for predicting epidemic onset. Differences in cultivar resistance explained part of epidemic onset variability, as did different timings of canopy closure, presumably due to associated microclimate changes. Moreover, meteorological variables were considered as potential reasons for variation in epidemic onset. The weather-dependent infection probability was assessed by daily infection values (DIV) in the range from 0 to 1 using hourly weather data. For calculating DIVs, the temperature effect was quantified by the proportions of the latent period (LP) relative to the optimum at 20 to 25 degrees C, established by artificial inoculation of sugar beet plants in growth cabinets. Artificial infection experiments further established that air relative humidity (RH) >95% or leaf wetness was required for infection and subsequent lesion development. Under field conditions, the probability of leaf wetness was 75% at RH >90%. Therefore, DIVs were set to 0 for RH

Allograft dermal implant (AlloDerm) in a previously irradiated field.

OBJECTIVE: To evaluate the integration of AlloDerm (LifeCell Corp., The Woodlands, TX) in a field exposed to external-beam radiation (EBR) by analyzing graft thickness, fibroblast recellularization, and neovascularization. STUDY DESIGN: Randomized control. METHODS: Thirty-six male Sprague-Dawley rats (n = 36) were randomly assigned to four groups. One hind leg of each rat was exposed to 20 Gy of EBR; the other limb served as the nonirradiated control. Two weeks after irradiation, AlloDerm was implanted into both hind legs. Grafts were harvested at 3, 4, 6, and 14 weeks after implantation and underwent histological analyses. RESULTS: There was no statistically significant difference in graft thickness, fibroblast count, or neovascularization between the grafts placed in the irradiated bed and the controls (n = 33, P = .332, P = .336, and P = .057, respectively). However, at week 3, fibroblast counts in the graft placed in the field exposed to EBR were significantly lower than those of controls (P = .019), although at week 14 the counts in the experimental limb were higher than those of the controls (P = .002). Graft thickness (P = .001) and fibroblast count (P < .004) were lower at week 14 than at earlier time periods for both the experimental and control grafts. CONCLUSIONS: In the rat model, graft thickness and neovascularization of the AlloDerm dermal implant do not appear to be adversely affected by a field that has received EBR. Fibroblast ingrowth may be hindered in the early postimplantation period but appears to normalize in the long term. Furthermore, overall graft thickness and fibroblast counts decrease over time, regardless of irradiation status.

Effects of external beam radiation on the allograft dermal implant.

OBJECTIVE: The purpose of this study was to define the effects of external beam radiation (EBR) on AlloDerm (LifeCell Corp) through the analysis of graft thickness, fibroblast recellularization, and neovascularization as a function of time. METHODS AND MATERIAL: Thirty-six male Sprague-Dawley rats (n = 36) were randomly assigned to 1 of 4 groups (A, B, C, and D). AlloDerm was implanted subcutaneously into the hind legs of each rat, and 20 Gy of EBR was administered to one side. Grafts harvested 1, 2, 4, and 12 weeks after radiation were subjected to blinded histologic analysis. RESULTS: In groups A, B, and C, the irradiated grafts showed a significant decrease in recellularization versus nonirradiated (P < 0.001). At 12 weeks (group D), recellularization equalized, but neovascularization was significantly less (P = 0.048) in the irradiated group. Graft thickness was unaffected. CONCLUSIONS: In the rat model, EBR of the implanted AlloDerm graft hinders recellularization in the early posttreatment period. However, EBR did not adversely affect graft thickness, recellularization or ultimate graft survival.

Clinical care pathways: decreasing resource utilization in head and neck surgical patients.

In this era of decreasing reimbursement, health systems have been forced to become more efficient and decrease resource utilization to remain financially viable. One of the methods of internal cost control has been the use of clinical pathways. Given the complexity of treatment of head and neck cancer patients, clinical pathways can help to standardize decision making and introduce uniformity in resource utilization. The objective of this study is to compare resource utilization and outcomes before and after implementation of a clinical pathway for head and neck surgical patients. We observed significant decreases in hospital costs as well as shorter lengths of stay after pathway implementation. It is our belief that a uniform management tool is beneficial in this complex disease.

Nerve cell adhesion molecule expression in squamous cell carcinoma of the head and neck: a predictor of propensity toward perineural spread.

OBJECTIVE: To evaluate head and neck squamous cell carcinomas (SCCAs) for the expression of nerve cell adhesion molecule (N-CAM). We propose that expression of N-CAM by tumor cells may be associated with perineural invasion in SCCA of the head and neck. METHODS: Seventy-six archived specimens of histologically proven SCCA were analyzed by immunohistochemistry for the expression of N-CAM. Positive and negative controls were used to assess staining. Two sections of each specimen were reviewed for the presence of perineural invasion. A retrospective chart review was performed for each patient that corresponded to the above specimens. RESULTS: Perineural invasion was present in 28 (37%) of the 76 patients evaluated for the expression of N-CAM. N-CAM expression was demonstrated in 38 (50%) of the 76 specimens. The incidence of N-CAM expression was significantly associated with perineural invasion (P = .002). There was no significant association between the presence of staining or the presence of perineural invasion and the incidence of locoregional recurrence, distant metastasis, or survival status; however, the mean follow-up was only 13.6 months (range, 1-49 mo). CONCLUSION: There is a positive correlation between the presence of N-CAM expression and perineural invasion in SCCA of the head and neck. The expression of this adhesion molecule by tumor cells may facilitate both homophilic cell-to-cell and heterophilic cell-to-substrate adhesion, thereby enabling the tumor cells to use the perineural tissues or neural cells, or both as a conduit for perineural spread.

Malignant tumors of the nose and paranasal sinuses: hospital of the University of Pennsylvania experience 1990-1997.

We reviewed our experience with sinonasal malignancies, which comprise less than 1% of all cancers, in order to determine the spectrum of disease and outcome after treatment. The medical records of 48 patients with sinonasal malignancies treated between 1990-1997 were reviewed for epidemiologic characteristics, tumor location and histology, treatment modalities, and tumor recurrence. Mean age was 58.5 years and 46% were male. Multiple sites of origin were common, including maxillary sinus (83%), ethmoid sinus (35%), and nasal cavity (40%). The histologic spectrum included squamous cell carcinoma (46%), adenoid cystic carcinoma (6%), and miscellaneous others (48%). Treatment included surgery and adjuvant radiotherapy (XRT) (58%), surgery alone (27%), XRT and chemotherapy (6%), surgery and chemotherapy (4%), and XRT alone (4%). Mean follow-up was 15 months (range 2-58). Recurrence was evident in nine patients (19%), 3 (33%) of whom had prior treatment before presenting to HUP. Of the six who recurred after initial treatment at HUP, five (83.3%) were treated with surgery and XRT and one (16.7%) was treated with surgery alone. Of the three that recurred after undergoing attempts at salvage (prior treatment and then treatment at HUP), one had received surgery alone followed by surgery and XRT, one had surgery and XRT followed by surgery and one had XRT followed by surgery alone. Our experience reveals surgery and XRT to be the modality of choice, particularly for advanced tumors, whereas surgery alone may be sufficient for small, well localized tumors. Neoadjuvant chemotherapy may offer improved local control; the future role of endoscopic surgery warrants further investigation.

Juvenile nasopharyngeal angiofibroma: an update of therapeutic management.

BACKGROUND: Juvenile nasopharyngeal angiofibroma (JNA) is a benign tumor of the nasopharynx composed of fibrous connective tissue and an abundance of endothelium-lined vascular spaces. The name of the disease is derived from the fact that it occurs during adolescence, almost exclusively in boys. METHODS: This study examines the natural characteristics of JNA, the imaging techniques used to diagnose and stage the neoplasm, and the treatment approaches used to manage the disease. RESULTS: Forty-three cases of JNA diagnosed and treated at the University of Texas M. D. Anderson Cancer Center over a 38-year period were reviewed for the study. The cases were divided into two groups, those occurring between 1955 and 1974 and those occurring between 1975 and 1991, to accurately represent the developments in diagnostic and treatment methodology during those time periods. CONCLUSION: The results of our study show that: (1) the imaging techniques used after 1965 (angiography, computed tomography, and magnetic resonance imaging) greatly improve the staging of JNA; (2) morbidity, recurrence, and intraoperative complications decrease when preoperative embolization and skull-based surgical approaches are used; and (3) surgical resection is the most common primary treatment, with chemotherapy and radiotherapy recommended as possible other options.

Laryngeal preservation for advanced laryngeal and hypopharyngeal cancers.

OBJECTIVE: To compare a single institutional experience with combination chemotherapy and radiation for laryngeal preservation with historical age-, sex-, stage-, and site-matched controls who underwent laryngectomy for cancer of the larynx or hypopharynx. DESIGN: Fifty-five patients with stage III or IV laryngeal and hypopharyngeal squamous carcinoma were prospectively entered into a protocol to receive three cycles of cisplatin (+/- bleomycin sulfate) and fluorouracil and radiation therapy from 1986 to 1991 (group 1). Following two cycles of chemotherapy, the clinical tumor response was assessed and responders received a third cycle of chemotherapy followed by definitive radiation therapy. Nonresponders underwent surgical salvage. Two patients in the surgical control group were matched to each protocol patient (n = 110, group 2) regarding site, stage, sex, and age (+/- 7 years) without knowledge of patient outcome. SETTING: A tertiary cancer referral center, The University of Texas M. D. Anderson Cancer Center, Houston. RESULTS: Following chemotherapy, the tumor response rate for group 1 was complete in 38% and partial in 31%. With a median follow-up of 24 months (group 1) and 37 months (group 2), the Kaplan-Meier 2-year disease-specific survival for group 1 and 2 was 63% and 74%, respectively (P = .251). Among group 1 patients, 67% retained their larynges. Local recurrences were more frequent among the laryngeal preservation group (P = .001), whereas distant metastasis was more frequent among controls (P = .35). Thirty-three percent (18/55) of group 1 patients required total laryngectomy. Examining these subsets of patients showed that of the 67% (n = 37) of patients who retained their larynges, their 2-year survival was 56%, not significantly different from their respective controls (n = 74), 71%. Additionally, 2-year survival among the 18 group 1 patients who required salvage laryngectomy was 75% as compared with 80% for their matched controls (n = 36). CONCLUSIONS: These results document the results of chemotherapy and radiation therapy in the treatment of patients with advanced laryngeal and hypopharyngeal cancers in preserving the larynx. Although local control is significantly compromised among these patients, there is no compromise in overall survival when combined with prompt surgical salvage.

Treatment of stage I and II oral tongue cancer.

We reviewed 156 previously untreated patients with squamous cell carcinoma of the oral tongue staged T1 and T2 to determine the incidence of nodal metastasis, and if elective neck dissection affected local/regional control or survival. Patients were divided into two nonrandomized groups: group 1, intraoral glossectomy only (102 patients); and group 2, intraoral glossectomy plus neck dissection (54 patients). Analysis revealed no significant differences for tumor location, histologic differentiation, status of margins, or clinical appearance; however, perineural invasion significantly adversely affected survival and local/regional control. In group 1 patients, 16.5% subsequently developed cervical metastasis, and 20.4% of patients in group 2 had occult nodal disease. The survival and local/regional control for group 1 patients subsequently developing nodes was 33% and 50%, respectively. The survival and local/regional control for group 2 patients with occult metastasis was 55% and 91%, respectively. We believe elective neck dissection is indicated for early staged oral tongue cancer.

Rationale for elective modified neck dissection.

A retrospective study was conducted to give surgeons direction in deciding which type of modified neck dissection is proper elective treatment for the patient with a clinically negative neck. The medical records of 428 previously untreated patients (seen between January 1, 1970, and December 31, 1979) whose necks (i.e., NO) were electively dissected and who had had a primary squamous carcinoma of the oral cavity, oropharynx, larynx, or hypopharynx were included. The three major types of modified neck dissections studied were the supraomohyoid, the anterior, and the functional. Sixteen percent (70 of 428) of the patients had multiple positive nodes and 6% (28 of 428) had evidence of extracapsular invasion. A unilateral supraomohyoid dissection was most often used for primaries of the oral cavity. Bilateral anterior dissection was common for cancers of the larynx and hypopharynx, and functional neck dissection was equally distributed among the primary sites. None of the patients with primaries of the larynx or hypopharynx had pathologically positive nodes in the submental or submaxillary triangles. Advanced T-stage was generally associated with a greater incidence of subclinically positive nodes. Thirty percent of the patients received postoperative radiotherapy. The total number of nodes removed, the number of positive nodes with or without extracapsular invasion, and the anatomic location of the positive nodes were correlated with the type of dissection, the stage and site of the primary cancer, the use of postoperative radiotherapy, the regional (neck) failure, and survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Malignant salivary gland tumors of the base of the tongue.

We present a 41-year retrospective study of patients with malignant salivary gland tumors of the base of the tongue treated at The University of Texas M. D. Anderson Hospital and Tumor Institute at Houston. This report characterized the patient group, documents their physical findings, analyzes survival, and draws some conclusions regarding clinical course and treatment options. When feasible, surgical resection is the preferred treatment, with planned postoperative radiotherapy when indicated by pathologic findings.

A predictive model for wound sepsis in oncologic surgery of the head and neck.

A prospective analysis of patients undergoing surgical resection of squamous cell carcinoma of the upper aerodigestive tract was performed in order to identify the patients at risk of postoperative wound infection and to develop a model predictive of wound infection. Fifty-nine patients who underwent extirpative clean-contaminated procedures--all of whom received cefazolin as the sole chemoprophylactic agent, were studied over a 1-year period. Twenty-three variables were recorded for each patient in the study. The overall rate of wound infection was 25.4%. Univariate analysis indicated that three variables were significantly related to the likelihood of postoperative wound infection. These included tumor stage (P = 0.0180), nodal stage (P = 0.0062), and duration of surgery (P = 0.0151). The Biomedical Computer Program (BMDP), a logistic regression program specifically designed for a binary dependent variable (infection vs. no infection) based on independent variables that may be continuous or categorical, was used in development of a model predictive of wound infection. T-stage, N-stage, and the presence of concomitant disease made up the combination of factors found to be most predictive of infection in our study population. Considering "success" to be the development of infection if the probability was 75% or higher, and the absence of infection if the probability was less than 25%, the multiple regression analysis model demonstrated a predictive success rate of 74.6%. Our results indicate that the risk of infection in patients undergoing clean-contaminated oncologic surgery of the head and neck is greatest for patients who have advanced disease that requires prolonged surgery in the presence of concomitant diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

Melanoma metastatic to cervical and parotid nodes from an unknown primary site.

The medical records of 96 patients with melanoma metastatic to cervical and parotid nodes from an unknown primary site have been reviewed. The use of various surgical procedures were correlated with local recurrence and survival rates. The size and number of involved nodes and the extent of nodal disease were compared with the type of treatment, and the age and sex of the patients, incidence of above-clavicle recurrence, and the 2, 5, and 10 year survival rates. The only significant correlations were the adverse affects of patient age over 50 years and multiple, large, pathologically positive nodes on local control and survival. Adjunctive chemotherapy and immunotherapy had no therapeutic value.