Characterization of coral-associated microbial aggregates (CAMAs) within tissues of the coral Acropora hyacinthus

Bacterial diversity associated with corals has been studied extensively, however, localization of bacterial associations within the holobiont is still poorly resolved. Here we provide novel insight into the localization of coral-associated microbial aggregates (CAMAs) within tissues of the coral Acropora hyacinthus. In total, 318 and 308 CAMAs were characterized via histological and fluorescent in situ hybridization (FISH) approaches respectively, and shown to be distributed extensively throughout coral tissues collected from five sites in Japan and Australia. The densities of CAMAs within the tissues were negatively correlated with the distance from the coastline (i.e. lowest densities at offshore sites). CAMAs were randomly distributed across the six coral tissue regions investigated. Within each CAMA, bacterial cells had similar morphological characteristics, but bacterial morphologies varied among CAMAs, with at least five distinct types identified. Identifying the location of microorganisms associated with the coral host is a prerequisite for understanding their contributions to fitness. Localization of tissue-specific communities housed within CAMAs is particularly important, as these communities are potentially important contributors to vital metabolic functions of the holobiont

Microbial mat compositions and localization patterns explain the virulence of black band disease in corals

Black band disease (BBD) in corals is characterized by a distinctive, band-like microbial mat, which spreads across the tissues and often kills infected colonies. The microbial mat is dominated by cyanobacteria but also commonly contains sulfide-oxidizing bacteria (SOB), sulfate-reducing bacteria (SRB), and other microbes. The migration rate in BBD varies across different environmental conditions, including temperature, light, and pH. However, whether variations in the migration rates reflect differences in the microbial consortium within the BBD mat remains unknown. Here, we show that the micro-scale surface structure, bacterial composition, and spatial distribution differed across BBD lesions with different migration rates. The migration rate was positively correlated with the relative abundance of potential SOBs belonging to Arcobacteraceae localized in the middle layer within the mat and negatively correlated with the relative abundance of other potential SOBs belonging to Rhodobacteraceae. Our study highlights the microbial composition in BBD as an important determinant of virulence

Diagnosis of Gastric Cancer in Early Stage — The Clinical Ob­servation of Operated Cases

1. An attempt has been made to find the diagnostic criteria for early gastric cancer. It is most important to detect the evidences or suspected features of the malignant growth in incipient stage in order to attain the radical cure by surgical operation. 2. Twelve patients with early gastric cancer (groups A and B) were selected out of 476 patients who had undergone gastrectomy during the past three years in the Okayama Saiseikai General Hospital. The other 6 patients in the &#34;precancerous group&#34; (group C) were also studied, who had abnormal epithelial proliferation in the resected stomach membrane during the same period. 3. The processes of discovery of early cancer have been described. Fairly precise diagnosis can be made in the mucosal carcinoma, but it is not in the ulcer-carcinoma. It was generally difficult to estimate the degree of the malignancy and the extension of the growth preoperatively. 4. The details of the diagnostic aids are as follows. i. Negative occult blood of stool does not always mean the definite diagnostic aid. ii. The malignant gastric change may occur even in non-anacidity. Further investigations should be followed up on gastric ulcer patients if malignant alteration is under the consideration. iii. Minor roentgenological findings, such as the absence or irregularity of mucosal folds, rigid and/or overlapped contour, localized absence or decrease of the peristaltic waves and absence or bow-shaped deformity of the angulus, are of important significance. Such changes should be minutely sought for by X-ray film examination. iv. On gastroscopy and gastrocamera photography, such changes as erosion or irregular granular thickening of the membrane with abnormal reddening and edematous appearance, irregularity of ulcer edge, uneven swelling on ulcer margin with reddening and unsharpness of the edge of adherent coat on ulcer floor, must be noted in the early gastric cancer. v. It is not safe to leave a patient having stomach ulceration under a mere conservative management because it is often quite difficult to dissolve the question of malignancy of the lesion with all sorts of examinations. vi. So far as clinical examinations have indicated malignancy, histological examination must be carried out immediately at the time of operation, even when malignant lesion is absent in inspection and palpation on the exposure of the stomach. vii. On the gross observation of the resected stomach, a particular attention must be paid to erosion, depression or atrophy, irregular granular thickening and abnormal reddening on the restricted areas of the mucosal surface.</p

A novel application of a cryosectioning technique to undecalcified coral specimens

Histological observations represent an important application to directly characterize the structure of tissues and locate host-associated and invasive microorganisms. Histological approaches have been widely employed in studies of the physiology, pathology and ecology of corals. However, the conventional preparation of histological sections requires decalcification of coral samples to remove the hard skeletal structure in a series of acid or EDTA solutions over a weeks’ period, causing potential disturbances in coral structures on prepared slides. In this study, we present an alternative method to prepare thin sections from undecalcified frozen coral tissues, which has been developed for retaining the structural integrity of histological sections including skeleton. Cross sections of normal and diseased (rapid tissue necrosis and black band disease) coral specimens prepared with this method displayed the complete structure of the coral fragments including soft tissues and skeleton structure at microscopic scales, thereby clearly showing the orientation of damaged tissues and associated microorganisms in relation to skeletal structures. This study demonstrates that the present cryosectioning method without the need for decalcification is a highly effective tool for in-depth understanding of coral tissue/skeleton interactions

In situ visualization of bacterial populations in coral tissues: pitfalls and solutions

In situ visualization of microbial communities within their natural habitats provides a powerful approach to explore complex interactions between microorganisms and their macroscopic hosts. Specifically, the application of fluorescence in situ hybridization (FISH) to simultaneously identify and visualize diverse microbial taxa associated with coral hosts, including symbiotic algae (Symbiodinium), Bacteria, Archaea, Fungi and protists, could help untangle the structure and function of these diverse taxa within the coral holobiont. However, the application of FISH approaches to coral samples is constrained by non-specific binding of targeted rRNA probes to cellular structures within the coral animal tissues (including nematocysts, spirocysts, granular gland cells within the gastrodermis and cnidoglandular bands of mesenterial filaments). This issue, combined with high auto-fluorescence of both host tissues and endosymbiotic dinoflagellates (Symbiodinium), make FISH approaches for analyses of coral tissues challenging. Here we outline the major pitfalls associated with applying FISH to coral samples and describe approaches to overcome these challenges

Sexual maturation of Girella punctata and G. leonina (Perciformes: Girellidae) in the neritic sea off the Pacific coast of Japan

The spawning ecology of the girellid fishes in Japanese waters has been reported almost only for Girella punctata, whereas little is known about Girella leonina. We examined sexual maturation of G. punctata and G. leonina collected from the coastal waters (neritic) of the Izu Peninsula and Tanegashima Island, based on gonadosomatic index (GSI) and gametogenesis, in order to clarify interspecific differences in spawning ecology. The GSI values of G. punctata in the Tanegashima Island region were markedly high in March, a month prior to the peak in April in the Izu Peninsula region. Girella punctata with elevated GSI had histologically mature ovaries and testes in spring in the both regions, suggesting spawning at this time of year. In contrast, the GSI values of G. leonina were much lower in the both regions, but the maximum GSI of both male and female G. leonina were slightly higher in the Tanegashima Island region than in the Izu Peninsula region. Furthermore, oogenesis in G. leonina was more advanced in the Tanegashima Island region. It is thus probable that Tanegashima Island is relatively near the spawning ground of G. leonina

Primary intrahepatic cholangiocarcinoma with sarcomatous stroma: case report and review of the literature

Abstract Background Hepatic carcinosarcomas, which include both carcinomatous and sarcomatous elements, are uncommon in adults. Although carcinosarcoma in hepatocellular carcinoma is occasionally reported, carcinosarcoma in intrahepatic cholangiocarcinoma (ICC) is an extremely rare ICC variant. Few such cases have been reported in English and no large study of its clinicopathological features exists. Case presentation Here, we report a 60-year-old man with an asymptomatic hepatic B infection who developed hepatic carcinosarcoma from an otherwise normal liver. The 6.0-cm tumor was accidentally discovered by PET-CT in a cancer examination. Serum examinations showed no elevation of tumor markers. He underwent left and caudate lobectomy of the liver. The diagnosis of intrahepatic cholangiocarcinoma with sarcomatous stroma was based on thorough pathologic examination and immunohistochemical staining. The tumor exhibited adenocarcinomatous and sarcomatous components; the adenocarcinomatous element was positive for epithelial markers, the sarcomatous element was positive for mesenchymal markers, but negative for epithelial markers. The patient made an uneventful recovery after surgery. At present, 14 months after surgery, he remains well with no evidence of tumor recurrence. Conclusions We report an unusual case of hepatic carcinosarcoma (intrahepatic cholangiocarcinoma with sarcomatous stroma) and discuss the etiology and prognosis of this rare disease