Peanut agglutinin binding to human prolactin-producing pituitary adenomas

Peanut agglutinin (PNA)-binding sites in human prolactin (PRL)-producing pituitary adenomas were examined by light and electron microscopy together with immunoblot analysis. At the light microscopic level, the majority of the PRL-producing adenoma cells stained positively for PNA in 15 of 20 cases. PNA binding observed in the cytoplasm had a granular appearance. PRL-producing cells adjacent to the adenoma tissue showed negative PNA staining. In normal pituitary glands, the PRL-positive glandular cells were negative for PNA staining. By electron microscopy, reaction products showing PNA-binding sites were detected in some of the secretory granules. Immunoblotting analysis revealed that the PRL bands corresponded to PNA-stained ones with the exception of the main 23-kDa band. PNA-binding sites have some relation to the secretory granules containing glycosylated forms of PRL. These observations suggest that PNA staining can be used as a valuable method to analyze human PRL-producing pituitary adenomas.     

H-ras p21 AND PEANUT LECTIN IMMUNOREACTIVITY OF HYPERPLASTIC, PRENEOPLASTIC AND NEOPLASTIC URINARY BLADDER LESIONS IN RATS

Hyperplastic, preneoplastic and neoplastic urinary bladder lesions induced by bladder carcinogens and toxins in the rat were evaluated for immunoreactivity with polyclonal or monoclonal antibodies to H- ras p21 or binding to peanut lectin with avidin-biotin immunocytochemistry. A low proportion (<20%) of hyperplastic and neoplastic bladder lesions induced by N-butyl-N-(4-hydroxybutyl)-nitrosamine and fixed in Bouin's fixative only were immunoreactive on the cell membrane with the antibodies to H- ras p21. Lectin binding was found for these lesions, as well, even in formalin-fixed tissue and for lesions induced by other carcinogens, but not in regenerative bladder hyperplasias after cyclophosphamide exposure or in bladder exposed to bladder tumor promoters. The latter lesions were also not immunoreactive with antibodies to p21. Our results suggest that this relatively simple technique might be used for identification and screening of tumors for involvement of ras oncogenes and carcinogen initiation.     

Peanut lectin: A useful tool for detecting Hodgkin cells in paraffin sections

Summary Using an extended peroxidase-antiperoxidase method receptors for peanut lectin (PNL) can be visualized in routinely fixed paraffin embedded tissue sections. PNL binding sites are numerous in human tissue. Each tissue, however, displays its specific binding spectrum and cellular binding pattern. 35 cases of Hodgkin's disease containing all histological subtypes were examined. A prominent, constant, and characteristic binding pattern in Hodgkin- and Reed-Sternberg-cells was found. PNL is proposed as an aid for detecting these cells in diagnostic histology. It might turn out to be a very useful reagent particularly in identifying the early lesion in Hodgkin's disease in which Hodgkin cells are small and scarce.     

Insect Management to Facilitate Preharvest Mycotoxin Management

Many species of insects can facilitate the entry of mycotoxin‐producing fungi to commodities such as cotton seed, maize, peanuts, and tree nuts. The mycotoxins most commonly associated with insect damage are aflatoxin and fumonisin. Insecticides will likely remain an important management tool, especially as predictive models for forecasting mycotoxigenic fungi or mycotoxins become available. Plants with high levels of resistance to insects that facilitate mycotoxins are likely to assist in mycotoxin management. Several studies now indicate Bt maize hybrids that express the protein throughout the plant can prevent fumonisin levels rising above guideline levels of 1–2 ppm when European corn borers (Ostrinia nubilalis) are the predominant insect pests.     

Ecology and Population Biology of Aflatoxigenic Fungi in Soil

Soil serves as a reservoir for Aspergillus flavus and A. parasiticus, fungi that produce carcinogenic aflatoxins in agricultural commodities. Populations in soil are genetically diverse and individual genotypes show a clustered distribution pattern within fields. Surveys over large geographic regions suggest that climate and crop composition influence species density and aflatoxin‐producing potential. Aflatoxigenic fungi reside in soil as conidia, sclerotia and hyphae, which act as primary inocula for directly infecting peanuts or for infecting aerial crops (corn, cottonseed, tree nuts) through wind and insect dispersal. Infected crops periodically replenish soil populations during drought years.     

Food Allergy Overview in Children

Food allergies have increased significantly in the past decade. An accurate history is crucial in approaching the management. At the outset, food intolerance must be distinguished from food allergies and, furthermore, these allergies should be classified into either an IgE, Non-IgE, or a mixed response. The clinical features vary from life-threatening anaphylaxis to milder IgE-mediated responses, atopic dermatitis, and gastrointestinal symptoms. The severity of the reaction and the potential risk for anaphylaxis on reexposure should be assessed. Milk, soy, egg, wheat, and peanut allergies are common in children, whereas peanut, tree nut, fish, shell fish allergies, and allergies to fruits and vegetables are common in adults. Structural proteins are important determinants of the severity of the reactions and may often predict the natural history and cross reactivity. Diagnostic work up must be guided by the clinical history. Skin testing and food-specific IgE done by standard methods are very useful, whereas oral challenges may be indicated in some situations. Majority of the patients outgrow their allergies to milk, soy, egg, and wheat, and some to peanut also, therefore, patients should be periodically reassessed. Novel diagnostic techniques which detect specific allergenic epitopes have been developed. Several newer therapies are promising.     

Nutrient and Antioxidant Properties of Oils from Bagasses,Agricultural Residues,Medicinal Plants,and Fodders

Objective: This study evaluated the physicochemical properties, fatty acid (FA) and phytochemical compositions, and free radical–scavenging potentials of oils from the bagasses: Costus afer stem (CA) and Saccharum officinarum stem (SB); agricultural residues; corn cobs (CC); tigernut chaff (TB); peanut hulls (GH); medicinal plants: Sphenocentrum jollyanum leaves (SJ) and Senna alata leaves (CS); and fodders: Pennisetum purpureum (PP), Panicum maximum (PM), and Chloris gayana stalks (CG).

Method: Oils from the samples were extracted using a mixture of n-hexane and isopropyl alcohol (3:2). The oils were analyzed for physicochemical properties using standard procedures, phytochemicals and FAs contents using gas chromatography-fluorescent ionization detection, and free radical–scavenging potentials using spectrophotometric methods of determination.

Results: The bagasse and residue oils contained lower moisture contents (1.13%–2.38%) and acid values (1.89–9.20?mg/KOH/g), while the GH oil produced the least refractive indices, saponification value, and oil yield. CA oil contained 78% saturated FA, while SB oils contained 73.65% saturated FA and an abundance of lignoceric, palmitoleic, oleic, and arachidic acid. CC oil contained mostly behenic acid (19.65%), and GH oil produced 87.04% saturated FA, while TB oil produced 56% unsaturated FA. Oils from SJ, CS, PP, PM, and CG contained between 48.34% and 57.09% unsaturated FA. The phytochemical composition showed that ribalinidine and sapogenin were most abundant in PM oil, while lunamarine, kaempferol, and catechin were most abundant in SJ oil. GH oil produced the highest amounts of phytate (53.81?µg/ml) and oxalate (39.47?µg/ml). TB oil and oils from SJ and CS, especially at higher concentrations, matched the scavenging potentials of the standards used.

Conclusions: Due to the thermal stability and amount of short chain fatty acids (SFAs) of the SB, CA, CC, and GH oils, they are more suitable for non-food industrial purposes, while TB, SJ, and CS oil properties are recommendable for therapeutic purposes, especially for relief of oxidative stress.