Chemical Ecology of the host searching behavior in an Egg Parasitoid: are Common Chemical Cues exploited to locate hosts in Taxonomically Distant Plant Species?

Parasitoids are known to exploit volatile cues emitted by plants after herbivore attack to locate their hosts. Feeding and oviposition of a polyphagous herbivore can induce the emission of odor blends that differ among distant plant species, and parasitoids have evolved an incredible ability to discriminate them and locate their hosts relying on olfactive cues. We evaluated the host searching behavior of the egg parasitoid Cosmocomoidea annulicornis (Ogloblin) (Hymenoptera: Mymaridae) in response to odors emitted by two taxonomically distant host plants, citrus and Johnson grass, after infestation by the sharpshooter Tapajosa rubromarginata (Signoret) (Hemiptera: Cicadellidae), vector of Citrus Variegated Chlorosis. Olfactory response of female parasitoids toward plants with no herbivore damage and plants with feeding damage, oviposition damage, and parasitized eggs was tested in a Y-tube olfactometer. In addition, volatiles released by the two host plant species constitutively and under herbivore attack were characterized. Females of C. annulicornis were able to detect and significantly preferred plants with host eggs, irrespectively of plant species. However, wasps were unable to discriminate between plants with healthy eggs and those with eggs previously parasitized by conspecifics. Analysis of plant volatiles induced after sharpshooter attack showed only two common volatiles between the two plant species, indole and ß-caryophyllene. Our results suggest that this parasitoid wasp uses common chemical cues released by many different plants after herbivory at long range and, once on the plant, other more specific chemical cues could trigger the final decision to oviposit.

Volatiles mediate host-selection in the corn hoppers Dalbulus maidis (Hemiptera: Cicadellidae) and Peregrinus maidis (Hemiptera: Delphacidae).

Volatile organic compounds (VOCs) released by plants are generally involved in host recognition and host selection for many phytophagous insects. However, for leafhoppers and planthoppers, host recognition is mainly thought to involve a phototactic response, but it is not clear if a host plant could be selected based on the volatile cues it emits. In this study we evaluated olfactory responses in dual choice tests of two Hemiptera species, Dalbulus maidis (De Long) (Cicadellidae) and Peregrinus maidis (Ashmead) (Delphacidae), vectors of maize-stunting diseases, to three maize (Zea mays L.) germplasms, a temperate and a tropical hybrid and a landrace. VOCs emitted by the germplasms were collected and identified using gas chromatography-mass spectrometry. The temperate hybrid released significantly more VOCs than the tropical hybrid and the landrace, and its volatile profile was dominated by (±)-linalool. D. maidis preferred odours emitted from the temperate hybrid, whereas P. maidis preferred odours from the tropical hybrid and the landrace over the temperate one. In order to test if linalool plays a role in the behavioural responses, we assayed this compound in combination with the tropical hybrid, to provide other contextual olfactory cues. D. maidis was attracted to the tropical hybrid plus a 0.0001% linalool solution, indicating that this compound could be part of a blend of attractants. Whereas addition of linalool resulted in a slight, though not significant, reduction in host VOC attractiveness for P. maidis. Both hopper species responded to olfactory cues in the absence of supplementary visual cues.

Fluoroscopy-guided placement of nasoenteral tubes in children using intermittent digital pulse fluoroscopy and last image save/grab technique.

AIM: To document the radiation exposure metrics, including fluoroscopic radiation time and radiation dose-area product, in children <18 years of age who undergo nasoenteral tube placement using fluoroscopic guidance with maximal dose-reduction techniques. MATERIALS AND METHODS: Following institutional review board approval, the age, gender, anatomical information, immediate procedure-related complications if any, fluoroscopy time, and radiation dose-area product were collected retrospectively in all paediatric patients who underwent fluoroscopically guided nasoenteral tube placement during a 5-year period. Three paediatric radiology faculty members, a radiologist assistant, and trainee residents during their paediatric radiology rotation performed the procedures on two different digital fluoroscopic machines using radiation-minimising techniques. Median values of the fluoroscopy time and radiation dose-area product were calculated and compared to values reported in the literature using the Wilcoxon procedure. RESULTS: There were 41 male and 33 female patients with a median age of 4 years and 6 months. Median fluoroscopy time used for placing a nasoenteral tube was 1.25 minutes with a median radiation exposure dose-area product of 0.245 Gy·cm(2). All patients had successful placement of nasoenteral tube without immediate procedure-related complications. CONCLUSION: Fluoroscopy-guided nasoenteral feeding tube placement can be performed successfully with minimal radiation exposure without compromising procedural success.

Chemosensitivity testing predicts survival in ovarian cancer.

The aim of this study was to assess the use of the MTT assay for chemosensitity testing to identify drug resistance and predict survival in patients with advanced ovarian cancer. Samples of ascitic fluid and/or solid biopsies were taken from 120 patients with FIGO stage III or IV ovarian adenocarcinoma at presentation. Cells were exposed for 48 hours to four concentrations of clinically relevant drugs including platinums, anthracyclines and alkylating agents. Cell survival was measured using the 3-4,5-dimethyl-2, 5-diphenyl tetrazolium bromide (MTT) assay allowing patients to be grouped as "sensitive" or "resistant" in vitro. Clinical data including age, residual disease, histological grade, treatment, response after initial treatment and overall survival were collected. There was a highly significant (p<0.0001) correlation of in vitro sensitivity with in vivo response in the patients who completed their therapy, with an 83% positive predictive accuracy for resistance. This translated in the longer term to an increased survival for the patients found to be sensitive in vitro to their therapy with a 5-year survival rate of 24% compared to 12% for the resistant group (p=0.033). These results suggest that MTT chemonsensitivity testing can predict response in ovarian cancer leading to the prospect of increased survival in this devastating disease by customising therapy to individual patients.

Lactobezoars: a patient series and literature review.

Lactobezoar is a compact mass of undigested milk concretions located within the gastrointestinal tract. Most often found in infants, they can precipitate gastric outlet obstruction, mimicking a variety of medical and surgical conditions. A common etiology and method of cure have yet to be elucidated. A review of the literature provides some insight into causes, clinical presentations, diagnosis, and management. Data from the Medical University of South Carolina further help dispel the belief that lactobezoars are isolated to pre-term infants on caloric-dense formulas. Findings suggest bezoar formation may be more common than previously thought and a high index of suspicion could help avoid costly evaluations for obstructive symptoms.

Emergency coronary artery bypass graft surgery in abciximab-treated patients.

BACKGROUND: Although the platelet antiaggregant abciximab is frequently used with percutaneous coronary interventions, results of emergency coronary artery bypass graft operations in patients recently treated with abciximab are poorly characterized. METHODS: During a 29-month period, 12 patients required emergency coronary artery bypass grafting within 12 hours (mean, 1.9 hours) of abciximab therapy. Our full standard heparin dose regimen was used (mean heparin dose, 53,000 U per patient). Each patient received a single platelet transfusion dose after protamine administration, and further blood products were transfused as necessary. Clinical outcome and transfusion requirements were compared with predicted results based on risk-adjusted historical patients. RESULTS: No patients died and none were returned to the operating room for coagulopathy-related bleeding. Per patient transfusion requirements were as follows: red blood cells, 3.6 units; apheresis platelets, 1.4 units; and fresh frozen plasma, 1.5 units. As compared with predicted values, there was no excessive incidence of mortality, stroke, or red blood cell transfusion requirements. CONCLUSIONS: Emergency coronary artery bypass graft operations using full-dose heparin can be performed successfully in acutely ischemic abciximab-treated patients. Prophylactic transfusion of platelets after protamine administration appears to be useful.

The clinical relevance of chemosensitivity testing in ovarian cancer.

The aim of this study was to assess the role of in vitro chemosensitivity testing in ovarian cancer using the MTT assay. Cells were separated from solid biopsy or ascitic fluid samples from 73 patients with ovarian adenocarcinoma, FIGO stage III to IV, on presentation. A 48 h drug exposure was followed by the MTT assay to determine sensitivity. Patients were treated by conventional regimens containing platinum. There was a marked variation in sensitivity to the platinum drugs between individual patients. Clinical data were available for 37 patients. Eleven out of seventeen (65%) patients in the sensitive group had a complete response to therapy, compared with 3 out of 20 (15%) in the resistant group (p = 0.005). The overall survival rates were 36% for the sensitive group compared with 18% for the resistant group (p = 0.37). This study suggests that chemosensitivity testing in ovarian cancer may be effective in improving initial clinical response.

Prevalence of occupationally related hand dermatitis in dental workers.

Occupationally related hand dermatitis has been attributed to frequent hand-washing, exposure to possible sensitizers and latex glove use. The authors conducted a study to determine the prevalence of occupationally related hand dermatitis in dental personnel. They found that 75 (19.2 percent) of 390 subjects self-reported they had a positive history of hand dermatitis. Further testing of 53 of these subjects indicated that only 9.4 percent reacted to the 45 allergens tested, and 3.8 percent had an allergy to latex.