Abstract Background : The rapid urease test and touch cytology have been used for the rapid detection of Helicobacter pylori infection. Recently, a modified rapid urease (MRU) test, which provides results in 20 min has been available on a commercial basis. To date, few reports have evaluated the accuracy of this test. This study evaluated the sensitivity, specificity, and accuracy of the MRU test and touch cytology to detect H. pylori in relation to the density of H. pylori infection determined semi‐quantitatively by using immunohistochemical stains. Methods : Biopsy specimens obtained from a total of 60 patients who underwent endoscopy for evaluation of gastroduodenal diseases were studied by using the MRU test, Giemsa stain for touch smear tissue and histological methods. An immunohistochemical stain was used as a standard, and the density of H. pylori infection was graded according to the number of individual bacteria seen as follows: grade 0 = 0; grade 1+ = 1–9; grade 2+ = 10–29; grade 3+ = 30–99; grade 4+ ≥ 100. The severity of gastritis was evaluated histologically in each specimen and compared with the density of H. pylori infection. Results : The MRU test had an overall sensitivity of 73%, specificity of 100% and accuracy of 85%. The Giemsa stain had a sensitivity of 91%, specificity of 100% and accuracy of 95%. The sensitivities of the MRU test and Giemsa stain decreased in mild H. pylori infection. In the MRU test, the sensitivity was 47% when the density of H. pylori infection was 1+, while 80–100% sensitivities were obtained when the densities of infection were ≥ 2+. With the Giemsa stain, the sensitivity was 80% when the density was 1+, while the sensitivity increased to 100% when the densities were ≥ 2+. The severity of gastritis determined by the Rauws scores showed a positive correlation with the density of H. pylori infection as evaluated by immunohistochemical staining. Conclusions : The MRU test had high sensitivity and specificity for moderate to severe H. pylori infection, but it may result in false‐negative results in tests for mild infection. As the MRU test has the advantages of shorter incubation times and low cost, a combination of the MRU test and the Giemsa stain for touch cytology may be the most time‐ and cost‐efficient tests in a clinical setting for the diagnosis of H. pylori infection.
The ultrastructure of Sertoli cell in the testes of Korean native goats was investigated by scanning and transmission electron microscopy to elucidate the relationship between germ cell and Sertoli cell processes in the spermiogenetic cycle. Type-A Sertoli cells at stage V of the spermiogenetic cycle and type-B Sertoli cells at stage VII of the spermiogenetic cycle were used for analysis. Morphologically, the Sertoli cell processes were classified into sheet-like and slender cord-like processes. The sheet-like process originated solely from the Sertoli cell column while the slender cord-like process projected either from the Sertoli cell column or the sheet-like process. Periodic acid (PA)-thiocarbohydrazide (TCH)-silver protein (SP)-physical development (PD)-positive granules were found diffusively both in the sheet-like and slender cord-like processes near the round spermatid, whereas they had accumulated near the head of the elongated spermatid. The morphological variation and glucoconjugate histochemical reaction of the Sertoli cell processes reflect nourishment, movement and transformation of the spermatogenic cells in accordance with spermiogenesis.
Objectives: Several methods are used to detect Helicobacter pylori (HP) infection. However, few reports have evaluated the accuracy of each method and compared the grade of HP infection with the severity of histological changes. HP infection was evaluated semiquantitatively in relation to the severity of gastritis, and the sensitivity, specificity, and accuracy of several methods to detect HP infection were compared. Methods: Biopsy specimens, obtained from a total of 64 patients who underwent endoscopy for evaluation of gastroduodenal diseases, were studied using a rapid urease test, culture, and histological assessment. An immunohistochemical method was used as the gold standard and graded according to the number of individual bacteria seen, as follows: 0 = 0; 1 += < 10; 2+= 10–29; 3+= 30–99; 4+= > 100. The severity of gastritis was evaluated histologically in each specimen and compared with the grade of HP infection. Results: The rapid urease test had a sensitivity of 53%, specificity of 100%, and accuracy of 73%. The culture method had a sensitivity of 75%, specificity of 100%, and accuracy of 86%. Sensitivities of the rapid urease test and the culture method decreased in a positive correlation with the decrease in total number of HP bacteria counted. Using the rapid urease test, sensitivity was < 30% when the grade of HP infection was ≤2+, whereas 100% sensitivity was obtained when the grade of HP infection was 4+. On the other hand, sensitivity of the culture method remained between 80% and 90% when HP infection was ≥2+. The severity of gastritis determined with Rauws scores increased in a positive correlation with the grade of HP infection as evaluated by immunohistochemical stain. Conclusions: The rapid urease test and culture of HP may result in false-negative tests for a mild infection, although they had high sensitivity and specificity for moderate to severe infection. Immunohistochemical stain provides a reliable semiquantitative diagnosis of HP infection and a positive correlation with histological changes. Clinicians should be aware of the characteristics of each method to detect HP infection and select the appropriate one(s) for their purposes.
The Golgi tendon organ (GTO) is an encapsulated fusiform mechanoreceptor siding in the musculotendinous junction of many animal species. Inhibitory function of afferent nerve fibers distributed from nearby motor units, the organ responds to active tension exerted onto the muscle. The morphological features of the equine GTO have not yet been elucidated. Additionally, there is some controversy regarding to the existence of the GTO in the equine superficial digital flexor tendon (SDFT). Therefore, immunohistochemistry and immunoelectron microscopy using alcian blue (pH 2.5) staining and the silver-enhanced colloidal gold method were carried out to determine both the location and characteristics of the GTO at the musculo-tendinous junction of the SDFT. A GTO with a fusiform structure of approximately 3 mm in length was found in the tendinous part. The lumen of the GTO was divided into compartments by septal cells. Each compartment contained collagen fibrils, nerve fibers and Schwann cells. This is the first report of the equine GTO.
Tektins are evolutionarily conserved filament-forming proteins localized in flagella and cilia, and have been reported to be involved in the stability and structural complexity of axonemal microtubules. Five mammalian Tektins (Tektin1–5) have been reported. Of these, Tektin2 (TEKT2) has been found to be required for normal flagellum structure and function. Tekt2-null sperm display flagellum bending and reduced motility, probably due to disruption of the dynein inner arm. However, the subcellular localization of TEKT2 in spermatozoa has not been clarified at the ultrastructural level. To elucidate the molecular localization of TEKT2 in flagella of rat spermatozoa, we performed confocal laser scanning microscopy, extraction of flagella followed by immunoblot analysis, and immunogold electron microscopy. Extraction of sperm flagella by SDS-EDTA resulted in complete extraction of axonemal tubulins, while TEKT2 was only partially released from flagella, suggesting that TEKT2 might be present in the peri-axonemal component, not directly associated with axonemal tubulins. Confocal laser scanning microscopy and pre-embedding immunoelectron microscopy revealed that TEKT2 is associated with the surface of outer dense fibers (ODFs). TEKT2 may function as an ODF-affiliated molecule required for flagellum stability and sperm motility.
The distribution pattern of collagen fibril diameter in the equine superficial digital flexor tendon (SDFT) is known to differ in central and peripheral areas of some regions. This study reports the essence of collagen fibril differences among different regions of the equine SDFT by transmission electron microscopic (TEM) and high-voltage electron microscopic observations and biochemical analysis. The distribution of large collagen fibrils increased but the density of collagen fibrils decreased from the proximal metacarpal region to the distal metacarpal region. Large collagen fibrils with an irregular cross-sectional profile were found more frequently in the middle metacarpal region than in other regions. Three-dimensional reconstruction of images of irregularly shaped collagen fibrils revealed that these fibrils are formed through fusion of small collagen fibrils with large ones. The amount of decorin, which reportedly inhibits the lateral fusion of collagen fibrils, decreased in the direction of the distal metacarpal region. On the other hand, the size of decorin gradually increased in the direction of the distal metacarpal region. These results suggest that regional differences in collagen fibril distribution and density of collagen fibrils in the SDFT are due, at least in part, to fusion of collagen fibrils and the concomitant regional differences in the amount and size of decorin.
