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The vesicular–arbuscular mycorrhizal fungus Glomus mosseae was examined by transmission electron microscopy and energy dispersive X-ray analysis. Electron-dense granules, found within vacuoles, were analyzed by X-ray analysis and found to contain high concentrations of phosphorus and calcium. These granules were similar in appearance to the polyphosphate granules described in other organisms. Highly vacuolated intercellular hyphae and vesicles possessed the greatest number of phosphorus granules. The granules were present in vacuolated arbuscular hyphae but absent from completely collapsed arbuscules. It was determined that the active arbuscule was the most probable site of breakdown of phosphorus granules. There were two other types of cellular inclusions, one vacuolar and one cytoplasmic, that could not be identified by X-ray analysis but that could easily be mistaken for phosphorus granules. It was concluded that general morphological appearance and location were not adequate criteria for the identification of phosphorus granules.

Electron microscopic observation of thin sections of rice (Oryza safiva L.) endosperm revealed two types of protein bodies (PBs): spherical and irregular-shaped ones. lmmunocytochemical localization studies using antibodies raised against purified glutelins, prolamines, and globulins indicated that the prolamines were localized in the spherical PB, whereas the irregular-shaped PB contained glutelins and globulins. We counted and measured the surface area and the relative volume of 2303 PBs randomly selected from two different developmental stages and from different locations within the endosperm. The ratio of spherical to irregular-shaped PBs was 1 :1.6. Double-label immunogold electron microscopic localization indicated that the globulins represented about 18% of the surface area of the irregular-shaped PBs. Based on our morphometric analysis, we estimate the relative contribution of glutelin as 53%, that of prolamine as 35%, and that of globulin as 12% of the total seed protein.Seed storage proteins can be divided into four classes based on their solubility properties. Albumins are water soluble, globulins are salt soluble, prolamines are soluble in aqueous alcohol solutions, and glutelins are soluble in alkali or acid (Shotwell and Larkins, 1989). Rice (Oryza sativa L.), a staple food crop for millions of people worldwide, has a seed protein content ranging from 5 to 12% (Villareal and Juliano, 1978). The major storage proteins found in rice are the glutelins, which according to previous studies, account for 80% or more of the total seed protein (Tecson et al., 1971;Juliano, 1972;Villareal and Juliano, 1978). The remaining 20% is divided as follows: albumins, 1 to 5%; globulins, 4 to 15%; and prolamines, 2 to 8% (Houston et al., 1968). It has been demonstrated that the relative contributions of each of the solubility classes of seed proteins can be influenced by genotype, growing conditions, and the analytical methods employed (Sugimoto et al., 1986;Ogawa et al., 1987;Huebner et al., 1990).The biosynthesis of rice glutelins and prolamines has been studied in detail by severa1 researchers (Yamagata et , 1982;Luthe, 1983;Wen and Luthe, 1985;Li and Okita, 1993). Glutelins are first synthesized as precursor proteins of 51 to 57 kD. These precursors are then proteolytically processed into a subunits of 34 to 39 kD and fl subunits of 21 to 22 kD. The end products are stored in specialized structures called PBs. A previous electron microscopic study found that glutelins are processed through the Golgi apparatus and are deposited in irregular-shaped PBs (PB type I). Rice prolamines have molecular masses in the 10-to 17-kD range (Mandac and Juliano, 1978;Kim and Okita, 1988;Masumura et al., 1990) and accumulate within distensions of the rough ER (Yamagata et al., 1982;. They are stored in spherical PBs (PB type 11). Recently, the relative contribution of prolamines to the total protein content of rice seeds has been re-examined. Traditionally, prolamines have been extracted with 70% ethanol. However, a study by Sugi...

Structural characteristics of aged (10 days) bovine longissimus and semitendinosus muscles as affected by thermal treatment were evaluated with scanning electron microscopy (SEM) and transmission electron microscopy PEM). Steaks were oven roasted at 177°C to internal temperatures of either 63, 68, or 73°C. At 63°C both muscle samples exhibited coagulation and denaturation of the perimysium and sarcolemma and progressively increased to near complete coagulation and denaturation at 73°C. Well-defined myofibrillar surface features were present in semitendinosus samples at 63°C and increased sarcomere denaturation and shrinkage were observed at the higher temperatures. Whereas, the overall topographical features of longissimus myofibrils were not well-defined and exhibited a granular appearance even at 63°C. TEM of samples heated to 63°C revealed less distinct myofibrils in longissimus than in semitendinosus samples. Disintegration of filaments in the I-band and shrinkage of filaments in the A-band occurred at 63°C. Increased disintegration of actin filaments in the I-band at the junction of the Z-disc and shrinkage and disruption of the A-band material occurred as temperatures were increased. Z-disc material remained intact with some evidence of disruption at the higher temperatures. Although progressive disruption of muscle fiber ultrastructure occurred as steaks were heated to higher internal temperatures, these changes did not result in increased muscle tenderness. Instead the samples became progressively less tender as internal temperatures were increased likely due to the shrinkage and hardening of filamentous material in the A-bands. Increased disintegration of filaments in the I-band as temperature was increased apparently did not contribute to an improvement in tenderness.

Disseminated gonococcal infection (DGI) often presents a diagnostic challenge. Through the novel application of molecular technology, a case is presented that suggests how the diagnostic sensitivity for this systemic complication of gonococcal infection can be improved. In a typical case of DGI seen in a homosexual man in whom all mucosal and blood specimens were culture negative, nucleic acid amplification testing (NAAT) helped to confirm the diagnosis. Both throat and skin lesion specimens tested positive for gonococcal DNA and this was confirmed with a supplementary porA pseudogene NAAT. The use of adjuvant NAAT assessment is recommended as part of the diagnostic work-up for suspected DGI cases.