Mondo shtuff from around the internet, all about MENINGES!
Prostaglandin D Synthase (β-Trace) in Human Arachnoid and Meningioma Cells: Roles as a Cell Marker or in Cerebrospinal Fluid Absorption, Tumorigenesis, and Calcification Process: Glutathione-independent prostaglandin D synthase (PGDS) is an enzyme responsible for biosynthesis of prostaglandin D2 in the CNS and is identical to a major cerebrospinal fluid protein, β-trace. Although PGDS has been identified recently in rat leptomeninges, little information is available about human meninges or meningiomas. Here, we report PGDS to be expressed consistently in 10 human arachnoid and arachnoid villi and in 21 meningiomas by immunohistochemistry, Western blot, and reverse transcription (RT)-PCR analyses. In arachnoid, PGDS immunoreactivity was seen in arachnoid barrier cells but was negligible in arachnoid trabecula and pia mater. In contrast, in arachnoid villi, PGDS was seen in core arachnoid cells rather than in the cap cell cluster or arachnoid cell layer. Meningioma cells also showed intense immunoreactivity in the perinuclear region, and it was often concentrated within meningocytic whorls and around calcifying psammoma bodies. Immunoelectron microscopic data, when compared with the ultrastructure, showed that PGDS was localized at rough endoplasmatic reticulum of arachnoid and meningioma cells. Western blot showed a 29 kDa immunoreactive band indicating PGDS, but the extent of expression was variable from case to case, which was compatible with immunohistochemical data. RT-PCR revealed PGDS gene expression in all meningiomas studied, regardless of histological subtypes, and also in human arachnoid villi. Because human arachnoid and meningioma cells exclusively express PGDS, it can be considered their specific cell marker. These results show functional differences in various types of meningeal cells attributable to differences in PGDS expression.
Leptomeninges | Meaning of Leptomeninges by Lexico: What does leptomeninges mean? leptomeninges is defined by the lexicographers at Oxford Dictionaries as The inner two meninges, the arachnoid and the pia mater, between which circulates the cerebrospinal fluid.
My botty best at summarizing from Wikipedia: the meninges are the three membranes that envelop the brain and spinal cord . in mammals, they are the dura mater, the arachnoid mater and the pia . primary function of the middle region is a mostly fibrous portion . it contains larger blood vessels that split into the capillaries in the pia mater . the dura mater is a sac that envelops the arachnoid mater and surrounds and supports the large dural sinuses carrying blood from the brain toward the heart . falx cerebri, the shape of the arachnoid does not follow the convolutions of the surface of the brain . it looks like a loosely fitting sac . the thin, transparent membrane is composed of fibrous tissue . the arachnoid is composed of an outermost portion with tightly packed cells . it is considered to represent an effective meningeal barrier between cerebrospinal fluid and blood circulation . the barrier layer is characterized the pia mater is pierced by blood vessels to the brain and spinal cord . its capillaries nourish the brain . acute meningococcal meningitis can lead to an exu the dura mater is attached to the skull, whereas in the spinal cord it is separated from vertebrae by a space called the epidural space . a subarachnoid hemorrhage is a subdural hematoma is located in a separation of the arachnoid from the dura mater . epidural bleeding may arise after an accident or spontaneously . meningitis and the spinal meninges were seen to be very simple . the dura keeps its identity in the spinal medulla, in the skull it fuses with the periosteum. the continuity of all meninges with the envelopes of nerves and with the filum terminale . Mammals retain the dura mater, and the secondary meninx divides into the arachnoid
