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Large oncoids (up to 14 cm) and microbialites are abundant in the Artinskian (Lower Permian) section of mid-Panthalassan Akiyoshi atoll carbonates. The oncoids and microbialites consist mainly of a tubular microproblematicum, girvanellid cyanobacterial filaments, microbial micrite crusts, and pore-filling sparry calcite cements. They are surrounded by intraclastic–bioclastic grainstone/rudstone, indicative of moderate- to slightly high-energy subtidal conditions. The microbial community was the primary boundstone-forming organisms on the Akiyoshi atoll during this time. It represents a transitional stage in a mid-Panthalassan reef succession between a cooler-water autotrophic Palaeoaplysina–microencruster community in the Gzhelian–Asselian and a warmer-water heterotrophic calcareous sponge–microencruster community in the Middle Permian. The flourishing mid-Panthalassan microbial community during the late Early Permian is related to enhanced alkalinity, increasing nutrient levels, elevated sea-surface temperatures, and the absence of major reef-building metazoans, which resulted from Gondwanan deglaciation, climatic changes, and a pulse of active volcanism.

A Palaeoaplysina–microencruster reef community is recognized in the Gzhelian–Asselian interval of the Taishaku and Akiyoshi limestones in SW Japan, which represent accreted Panthalassan atoll carbonates. In a reef-core area of the atoll, the alga Palaeoaplysina acted as a framebuilder and was associated with various binders (e.g., Tubiphytes, Archaeolithoporella, cystoporate bryozoans, and microbialites) and sediment-bafflers such as fenestrate and cryptostomate bryozoans and phylloid algae. In a subtidal environment of the back-reef area, Palaeoaplysina and phylloid algae flourished as sediment-bafflers. A microbial community, including Tubiphytes and sessile foraminifers, was predominant in a very shallow, peritidal environment of the back-reef area. Palaeoaplysina was distributed mainly along the northern margin of Pangea and is regarded as a boreal element. During Gzhelian–Asselian time, its distribution extended to the tropical or subtropical Panthalassa Ocean due to global cooling. On the Akiyoshi atolls, the Palaeoaplysina–microencruster community was succeeded by a sponge–microencruster community in the late Early Permian. The timing of this biotic turnover is similar to that of a change in climate from icehouse to greenhouse conditions, and coincides with superplume activity beneath the mid-Panthalassa Ocean.

This paper traces late Palaeozoic second-order sea-level change based on the stratigraphy of the Akiyoshi Limestone, an accreted Carboniferous-Permian Panthalassan atoll carbonate succession in SW Japan. The estimated subsidence of a volcanic edifice and the variable rate of carbonate accumulation reveal the long-term sea-level history of the late Palaeozoic. During Bashkirian time, just after the lowstand stage at the mid-Carboniferous boundary, a slow progressive long-term sea-level rise began. This sea-level rise then increased greatly during Moscovian time. The following Kasimovian to Asselian interval represents a stable highstand stage. Beginning in the Sakmarian, sea level fell slowly and became stable in the Yakhtashian (= Artinskian). This stable sea level was maintained into the Midian (= Capitanian), although a small-scale sea-level rise of approximately 55–70 m is recognized in the Murgabian (= Wordian). The most noteworthy aspect of this change of sea level is the rapid sea-level rise during the Moscovian that created a very large accommodation space and resulted in accumulation of a thick carbonate succession. The eustatic rise from the earliest Bashkirian lowstand to the latest Moscovian highstand had an amplitude of approximately 230–240 m. Such a large-scale eustatic rise in the long-term sea-level change would most likely be caused by greater uplift of the ocean floor along the mid-oceanic ridges, as a result of an increase in the production of oceanic crust during that time.

Detailed core examination of Middle Permian (Guadalupian) lagoonal successions of mid-Panthalassan atoll carbonates (Akiyoshi Limestone) revealed distinct stratigraphic variation of facies and sequence stacking patterns. The long-term sea-level change reconstructed from the atoll stratigraphy of the Akiyoshi includes a Bolorian to Midian gentle sea-level fall, punctuated by a short-lived Murgabian sea-level rise. These sea levels can be regarded as eustasy, judging from the monotonous subsidence of the Akiyoshi atoll and its good correspondence with the sea-level curves of other areas. Two sequence types are defined. Sequence type A consisting of shoal to lagoon grainstone occurred in low accommodation during the sea-level highstand-to-falling stages of the late Murgabian to Midian. This sequence type is bounded by two successive subaerial exposure surfaces and exhibits the uneven but generally low δ13C values throughout the section. In contrast, sequence type B occurred in increasing accommodation during the sea-level rise of the early Murgabian. This sequence type represents a composite sequence comprising parasequences and consists of various types of facies such as peritidal lime-mudstone, lagoonal packstone and boundstone, and shoal grainstone. Sequence type B is characterized by consistently high δ13C values except for the negative shift immediately below the sequence-top surface. These lines of evidence demonstrated that long-term eustatic sea-level change obviously controls the variations of sequence types in atoll carbonates.

Carbonate rock cores drilled on the Kikai Seamount, northern Philippine Sea are examined for better understanding of tectonic history of the northern Philippine Sea. The Kikai Seamount, the summit of which is at 1960 m water depth, is an isolated high on the northwestern part of the Amami Plateau formed by subduction-related arc volcanism, and is situated close to the axis of the Ryukyu Trench in front of the Ryukyu Arc, SW Japan. The seamount is capped with shallow-water carbonates such as coral rudstone. Detailed examinations of lithology, larger foraminiferal assemblages, and Sr isotope composition reveal that the core material comprises Miocene carbonates unconformably overlain by Early Pleistocene carbonates. It indicates rapid subsidence of the Kikai Seamount since the Early Pleistocene. The most probable cause of rapid subsidence is collision and subduction of the Amami Plateau laden with the Kikai Seamount. The rapid subsidence may have started when the western corner of the plateau reached the Ryukyu Trench and began subduction beneath the Ryukyu Arc. The onset of the subsidence is likely to be controlled by a motion change in the Philippine Sea Plate. The latest change in subduction direction from north to northwestward into northwestward to west has been believed to have occurred at 1-2 Ma during latest Pliocene to Early Pleistocene time. The change of direction resulted in the shift from oblique into right-angle subduction of the plate beneath the Ryukyu Arc and also the onset of the collision and subduction of the Amami Plateau.

It is well known that the Wilms' tumor gene WT1 plays an important role in cell proliferation and differentiation, and in organ development. In this study, to examine the role of the WT1 gene in lineage determination, fetal liver cells from LacZ-transgenic mice, in which WT1 expression was marked by the expression of the LacZ gene driven by WT1 promoter, were FACS-sorted according to LacZ expression of high (LacZ(++)) or undetectable (LacZ(-)) levels, which paralleled endogenous WT1 expression levels. LacZ(++) fetal liver cells were enriched by hepatocyte and endothelial progenitor cells. These results indicated that WT1 expression is a common marker of both hepatocyte and endothelial progenitors. These results also implied a role of the WT1 gene in lineage determination.

For a quantitative investigation of eosinophil activation in perennial allergic rhinitis, eosinophil cationic protein (ECP) concentrations were measured by a radioimmunoassay in serum, nasal secretions (ECPWN) and in the supernatant of these nasal secretions (ECPsup) obtained from normal subjects and allergic patients. Levels of ECPWN and ECPsup were higher than that of ECPserum. ECPsup showed a positive correlation with clinical severity, despite the lack of a significant correlation with eosinophilia in nasal smears. ECPWN and ECPserum showed no significant correlation with any of these clinical parameters. There was a weak tendency toward an increase in histamine sensitivity of the nasal mucosa of allergic patients with higher ECPsup although this was not statistically significant. These results suggest accumulation and activation of eosinophils in the allergic nasal mucosa, and also indicate that ECPsup may be a clinical parameter of perennial allergic rhinitis.