Marion R. Wells

External Morphology of Larvae of Chordodes morgani (Nematomorpha)

The surface features of larvae of a gordian worm, Chordodes morgani (Gordioidea), studied by scanning electron microscopy, were compared to those of other larval nematomorphs, until now known only from light microscopical studies. Larvae of C. morgani have a cylindrical body with 22 to 24 superficial segments, superficially divided at an ectodermal septum into a presoma and a trunk with a roughly 90? bend. Papillae are located distally on the proboscis, the base of which is surrounded by circles of spines or scales. Although the major features of the larvae are similar to those known in other species, details visible with SEM hold promise for providing useful diagnostic characters. Additional key words: horsehair worm, gordian worm Several electron microscropical studies have described adult features of gordian worms (e.g., Zapotosky 1971; Eakin & Brandenburger 1974; Chandler & Wells 1989) and others have treated the ultrastructure of larval forms (e.g., Zapotosky 1974, 1975). Less attention has been given to external features of larval forms (e.g., see Hyman 1951; Poinar & Doelman 1974), and such studies to date have been based on light microscopy. Our objective was to examine, using scanning electron microscopy (SEM), the external morphology of larvae of Chordodes morgani in order to document features that might be used as diagnostic characters, and to better understand their biology. Descriptions of adults of Chordodes morgani MONTGOMERY 1898 were augmented and C. morgani synonymized with C. puerilis MONTGOMERY 1898 by Montgomery (1901). Camerano (1915), in his revised monograph on gordian worms, published important diagnostic features characteristic of adults of C. morgani. Chandler (1985) reviewed the taxonomy and distribution of this species in North America.

Adenosine triphosphatase activity in brain, intestinal mucosa, kidney, and liver cellular fractions of the red-eared turtle following in vitro treatment with DDT, DDD, and DDE.

Increasing awareness of the environmental effects of organochlorine insecticides has stimulated research on the effects of these ccmpounds on active transport across cellular membranes. The effects of DDT on the ATPase systems of liver, intestinal mucosa, cloacal bladder, and kidney tissue of 5 turtle species were studied by PHILLIPS and W~,T~q (!974). Their data indicated that the total (Na +, K +, Mg +2) -, Mg +2-, (Na +, K+)-dependent ATPases in the tissues of all 5 turtle species were significantly inhibited by 53 uM DDT. There was some inhibition and stimulation following treatment with 5.3 uM DDT.

Ontogeny of the oral apparatus of the tadpole of Bufo americanus

The development of the oral apparatus of tadpoles of Bufo americanus was described from late embryonic through to metamorphic stages. Although sufficiently detailed developmental studies are not common, especially of species with tooth row formulae greater and less than 2/3, it appears that differences in timing rather than in sequence are the primary interspecific differences. Species with rapid developmental times (e.g. Bufo) seemingly start and complete developmental sequences slightly earlier than species with longer developmental times. Species with labial tooth row formulae greater than 2/3 start development sooner, complete it later and retain mouth parts longer into metamorphosis than species with 2/3 tooth rows. Lentic species tend to form the oral structures later and faster and atrophy the oral apparatus earlier and faster than lotic forms. For these reasons, oral development is often discordant with features of limb development used in staging.

Comparative acute toxicity of DDT metabolites among American and European species of planarians

1. DDT metabolism in a North American species of planarian leads to the formation of metabolites more toxic than the parent compound. 2. The increased toxicity of DDT metabolites is similar to acute toxicity data reported previously in a European species. 3. It is suggested that planarians lack a direct mechanism for DDT detoxification, since two North American and one European species are known to metabolize DDT initially to DDE and DDD.

Effect of the bioflavonoid morin on HEp-2 cells.

Bioflavonoids are plant compounds which aid in disease resistance (MariniBettolo and Monache 1977) and attract pollinating insects (Thompson et al. 1972). Flavonoids have been shown to affect biological systems variably, having antibacterial, antiviral (Miski et al. 1983), antifungal (Donnelly 1977), mutagenic (Brown 1980), antineoplastic and/or enzyme inhibitory properties (Pritsos et al. 1985; Bohmont et al. 1987; Hodnick et al. 1986; Duval et al. 1988). Antibacterial activity against Mycobacterium phlei was demonstrated in five 5,6,7-trisubstituted falvones which were extracted from Gompherena rnartiana and G. boliviana (Pomilio et al 1992). The flavonoid cirsimaritin, which was extracted from the leaves of Salvia palaestina, was demonstrated to have high activity against Staphylococcus aureus, S. epidermitis, Echerichia coli, Klebsiella pneumoniae, Proteus vulgaris and Pseudomonas aeruginosa (Miski et al. 1983). Antiviral activity was discovered in baicalin, a flavonoid extracted form Seutellaria baicalensis georgi, which inhibited human T and B cells via inhibition of the reverse transcriptase of infected ceils (Baylor et al. 1992). Further, flavonoid inhibition of reverse transcriptase activity in Moloney murine leukemia infected cells has been reported (Chu et al. 1992). For example, a number of flavonoids were shown to inhibit the activity of succinoxidase (Hodnick et al. 1986) and other flavonoids have been reported to inhibit mitochondrial respiration via inhibition of NADH oxidase, succinoxidase and ATPase (Bohmont et al. 1987). Mitochondrial enzymes are not the only enzymes affected by flavonoids. The flavonoid dichlone interferes with liver glycolysis in rats via inhibition of glutathione reductase (Pristos et al. 1985). Antineoplastic activity has been demonstrated in the cytotoxic flavonoid eupatorin which displayed cytotoxic activity against human carcinoma of the nasopharynx (Kupchan et al. 1979). Three flavonoids with inhibitory activities against Epstein-Barr virus early antigen induction by a tumor promoter have been isolated (Murakami 1992). Further, twelve flavonoids which inhibited antineoplastic activity against adenocarcinoma 755, Friend virus leukemia, Lewis lung carcinoma and Walker carcinosarcoma 256 have been reported (Edwards et al 1979).

Food Laws and Regulations

A paramount objective of the food industry is to provide a continuing supply of safe, wholesome foods for the public. To achieve this goal, food producers must be concerned about possible deterioration of foods, their contamination with microorganisms or potentially hazardous chemicals (e.g., residues of pesticides used in agriculture), and the safety of additives or other materials used in food processing.

Meat, Poultry, and Fish

In this discussion, meat is defined as the flesh of cattle, swine, sheep or goats that is consumed for food. It consists of muscle fibers held together by connective tissue and interspersed with nerves and blood vessels, which normally accompany the tissue. A single muscle contains a number of fiber bundles, held together by a sheath of connective tissue, the epimysium. Groups of fibers are associated into fiber bundles which, in turn, are surrounded by a sheath of connective tissue, the perimysium. The basic unit of muscle is the fiber, and it is bounded by the endomysium and sarcolemma.

Milk and Milk Products

Milk and milk products , Milk and milk products , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزیMilk is the normal secretion of the mammary glands for the feeding of the young of mammals. In the United States, the primary milk in commerce is cow’s milk. The responsibility for insuring the quality of this food product rests primarily with the individual states rather than with the federal government. Consequently, legal definitions of milk are not uniform within the United States. The U.S. Public Health Service (USPHS) has encouraged the adoption of adequate and uniform state and local control legislation. The following definition from its Grade A Pasteurized Milk Ordinance (1965) has been adopted by a majority of the states: “Milk is hereby defined to be the lacteal secretion, practically free from colostrum, obtained by the complete milking of one or more healthy cows, which contains not less than 8 1/4;% milk solidsnot-fat and not less than 3 1/4% milk fat.”

Coloring Agents and Color of Foods

Color is unconsciously incorporated into our impressions of foods because our eyes are constantly supplying the brain with color information that is instinctively associated with all other information about any given food. Radishes are “red,” bananas are “yellow,” and lettuce is “green.” In fact, we associate a particular color with almost every food we come in contact with in our daily lives. Thus, color is a significant factor in consumer acceptance of foods, and consumers automatically associate certain color characteristics with fresh and wholesome quality. This evident characteristic of foods is included in the quality standards for fresh and processed fruits and vegetables, fats and oils, meats, dairy products, poultry, and eggs. In the processing, preservation, and storage of some food products, the “natural color” may be destroyed. This fact has spurred food processors to develop methods for retaining the best possible color in foods.

Instrumental Methods Used in Food Analysis

The development of solid state electronics, grating optics, microprocessors, and minicomputers represents but a few of the outstanding changes that have occurred in analytical instruments over the past decade. Instruments are, as a result of these developments, more stable and reliable, and afford the food chemist more convenient techniques of data acquisition.