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 β-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.

     

An assessment of test criteria for evaluating the performance and integrity of sterilizing filters

Measurements of serum calcitonin (iCT) were performed in 300 relatives of 43 Norwegian patients with medullary thyroid carcinoma (MCT). Prior to the screening, familial occurrence of the disease was known in only one of the families. Persistant hypercalcitoninemia (serum levels greater than 0.50 ng/ml) was demonstrated in 2 healthy persons from this family and in 3 first degree relatives of 2 patients with apparently sporadic disease. Additional 7 relatives of 5 other "sporadic" cases showed elevation of serum iCT on one occasion, while later controls revealed normal values. Twenty persons had high normal serum levels (0.35 ng/ml less than or equal to iCT less than 0.50 ng/ml). The significance of transitory hypercalcitoninemia and high normal values are at the present unknown, but these persons will have further tests. Stimulation tests for iCT secretion were found to be of limited value in distinguishing between normal and pathological serum iCT. All individuals found to have chronic hypercalcitoninemia belonged to families in which the probands showed one or several of the following "high risk" factors: A positive history of thyroid disease, early age of onset, bilateral presence of the thyroid tumour, association with other endocrine or peripheral neurogenic tumours, and marphanoid habitus. The iCT screening was however negative in the relatives of the two probands revealing 4 and 5 of these factors. Since neither the family history nor the presence or absence of "high risk" factors distinguished between sporadic and familial cases, it is concluded that serum iCT measurements should be carried out in primary relatives of all patients with MCT.     

Effects of phenobarbital and diazepam on imipramine-induced changes in blood pressure, heart rate and rectal temperature of rats

To investigate the safety of anticonvulsants in doses found equipotent in suppressing imipramine induced convulsions, the effects of diazepam (1.8 mg/kg) or phenobarbital (40 mg/kg) following a toxic dose of imipramine (50 mg/kg) on heart rate, blood pressure and body temperature were examined in male Wistar rats. Administration of imipramine alone resulted in significant decreases in blood pressure, heart rate and rectal temperature. Phenobarbital or diazepam alone failed to significantly affect any of these parameters apart from a slight reduction in rectal temperature seen with phenobarbital. Diazepam given after imipramine antagonized the imipramine-induced decrease in heart rate but increased the hypotensive and hypothermic effects. Phenobarbital failed to significantly affect the imipramine-induced changes in any of the physiological parameters studied. The present data suggests that phenobarbital may be preferable to diazepam in treatment of imipramine-induced convulsions.     

The early detection of colorectal cancer

A review of the American Cancer Society's statistics for colorectal cancer indicates that there has been little improvements in the survival rate for this disease in the past 25 years. Although there have been advances in surgical techniques, radiation therapy, and chemotherapy, the key to improved survival rates is earlier diagnosis. A significant percentage of patients continues to present with regional or distal metastasis at the time of their initial diagnosis. Both proctosigmoidoscopy and guaiac impregnated filter slide paper methods have been productive in diagnosing this disease at an earlier stage. The "Hemoccult" test, however, is inexpensive, can be used on a routine basis, is easier for patients to perform themselves, and is aesthetically pleasing. It represents a significant cost savings compared to proctosigmoidoscopy and should be advocated for routine use in all patients over 40 years of age. Although there continues to be a role for local and regional mass screening programs, significant improvements in colorectal survival rates cannot be expected until routine application of this type of screening is practiced.     

Preliminary observations on an intervention program for heavy smokers

Each of 571 smokers selected one of three methods of smoking cessation: group therapy, individual counseling, and hypnosis. One-year results suggest little difference between the three methods in producing ex-smokers. All methods produced an average success rate of approximately 20%. It should be noted, however, that with all types of verbal or verbally related therapy it is not known precisely how these techniques work or whether the outcomes are really a function of what is put into the therapy by the treatment agent and/or the recipient. It was generally found that younger, more educated smokers chose hypnosis; older, more educated smokers chose group therapy; and older, less-formally educated smokers chose individual counseling while the youngest and generally less educated smokers chose to become nonattenders and not take part in therapy. These results have important implications for designing optimal treatment programs which will be acceptable and effective for the greatest number of smokers.     

Renal lymph protein in the rat

Renal lymph and systemic (posterior) lymph were studied in hydropenic rats. As a consequence of the anatomical arrangement of collecting lymphatics near the kidney, mixed renal and systemic lymph tributaries are situated in such a way that sampling pure renal lymph is difficult. Pure renal lymph contains 1.0 +/- 0.1 g/100 ml total protein with an albumin-to-globulin (A/G) ratio of 2.1 +/- 0.1. Mixed renal and extrarenal lymphatic tributaries contain 3.3 +/- 0.2 g/100 ml total protein with an A/G ratio of 1.8 +/- 0.2. Corresponding values in the plasma are 4.9 +/- 0.2 and 1.2 +/- 0.1 g/100 ml, respectively. Previous studies in which the concentration of renal lymph protein was determined as 30-50% of that in plasma were probably in error due to contamination of renal samples by posterior lymph ducts. The amount of systemic and renal lymph mixing is highly variable from one animal to another. Our renal lymph samples in carefully controlled and prepared Munich-Wistar rats contained a total protein uniformly 20% of that in plasma.     

Systemic lupus erythematosus in children: the complex problems of diagnosis and treatment encountered in 101 such patients at the Mayo Clinic

Between 1945 and 1970, 101 children (86 girls and 15 boys) with systemic lupus erythematosus were evaluated at the Mayo Clinic. Only 9 children were less than 9 years old at the time of diagnosis. The most frequent presenting complaint was arthralgia; fever, fatigue, and a "butterfly" malar rash also were common. Renal involvement, found in more than 76 per cent of patients, was a prognostically poor sign. The overall survival of children with renal involvement is improved by the use of adequate steroid therapy.     

Persistent acute renal failure with renal artery stenosis: cure following reconstructive arterial operation

A case of acute renal failure is reported in which renal function returned after surgical correction of renal artery stenosis to the sole functioning kidney. Acute renal failure associated with renal vascular lesions is reviewed. Although often clinically apparent vascular obstruction may be asymptomatic and should be considered in cases of prolonged acute renal failure.