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1. A small spheric structure.
2. A sporangiallike structure filled with endospores at maturity, produced within tissue and in vitro by Coccidioides immitis.
[LL. sphaerula, dim. of L. sphaera, sphere, ball]


Etymology: Gk, sphaira, ball
a small ball.


A thick-walled, nonbudding structure recognized as the tissue form of Coccidioides immitis; variable in size, it may contain endospores or granular material. When the spherule ruptures, it releases endospores into the surrounding tissues.
[LL. sphaerula, dim. of L. sphaera, sphere, ball]


a thick-walled structure containing large numbers of fungal spores.
References in periodicals archive ?
A 2002 study "pulsed" dendritic cells from infected patients and nonimmune individuals with coccidioidal antigen derived from spherules and demonstrated lymphocyte proliferation in response.
Direct examination: Direct microscopical examination of the secretions (alveolar aspirate, cerebrospinal fluid, exudate) stained with calcofluor-white (which joins the chitin or cellulose of the cell wall) and observed in a fluorescence microscope, allow the visualizing the spherules with a 22% sensitivity.
The results were interpreted as indicating the presence of spherical fine-grained (~ 4-5 nm) magnetite particles, suggested to come from weathered glass spherules produced by the Chicxulub impact.
Moreover, industrial spherules may contaminate the natural glasses, both at the outcrop and during laboratory treatments [3-5].
Multiple methods exist for the diagnosis of coccidioidal infection, including microscopic detection of endospore containing spherules within tissue or fluid samples, molecular detection using nucleic acid amplification with polymerase chain reaction, cultures on fungal or bacterial media, and serologic testing.
Investigating 18 sites across North America, Europe and the Middle East, Kennett and 28 colleagues from 24 institutions analyzed the spherules, tiny spheres formed by the high temperature melting of rocks and soils that then cooled or quenched rapidly in the atmosphere.
The researchers haven't discovered any so-called shocked minerals in the spherule layers.
The spheres appear to accumulate in the leaky vasculature, or blood vessels, of tumours, releasing their cargo in a controlled, sustained fashion as the spherule walls and scaffolding break down in the bloodstream.
It discusses application of molecular approaches to identify key proteins expressed during arthroconidial and spherule morphogenesis at each stage of the disease process and to dissect the corresponding interactions with the immune system.
In the uppermost region of the shaft, cells that resemble the spherule cells of the coelom can be found between tooth and jaw [ILLUSTRATION FOR FIGURE 7 OMITTED] (for review of coelomocytes see Smith, 1981).
3,4) Coccidioidomycosis may extend to meninges, bone, skin, lymph nodes, and subcutaneous tissue; it is caused by Coccidioidis immitis, a 10- to 60-[micro]m spherule yeast that contains endospores.