Carlos E. Peña

EXPERIMENTAL PRODUCTION OF NEUROFIBRILLARY DEGENERATION 2. ELECTRON MICROSCOPY, PHOSPHATASE HISTOCHEMISTRY AND ELECTRON PROBE ANALYSIS.

1. Electron microscopy has demonstrated the fibrillar content of the neuronal lesions in rabbits treated with alum phosphate. 2. The filaments involved in these Alzheimer-like tangles are less than 150 Å wide, have side branches, and are perhaps tubular. They are similar to the filaments found in the human disease. 3. Traces of aluminum were found in the affected rabbit neurons by the Philips Electron Probe Analyzer. Neither aluminum nor other elements were found by similar analysis of human neurofibrillary tangles. 4. The alum-induced tangles are contrasted with the lesions in distended axons of rats treated with imidodiproprionitrile.

Mixed capillary hemangioblastoma and glioma. A redefinition of the 'angioglioma'

The histopathologic features of four cases of mixed capillary hemangioblastoma and glioma are described. In three cases, two of which arose in the cerebellum and one in the spinal cord, the hemangioblastic component may have originated from a neoplastic proliferation of the exuberant vascular stroma in a glial tumor. In a fourth case, a cerebellar hemangioblastoma was surrounded by a peripheral rim of atypical neoplastic-looking astrocytes (“reactive glioma”). The controversial concept of the “angioglioma” is reviewed, and it is proposed that the term be used to designate only true mixed tumors of glial and vascular tissue origin whose histologic features conform to the examples described in this report.

Lymphomatoid granulomatosis with cerebral involvement

SummaryLight and EM study of a case of lymphomatoid granulomatosis revealed a pleomorphic lymphoreticular cell infiltrate, angiitis and necrosis with involvement of the brain, lungs, skin and right ear of a 30 year old woman. Cells comprising the infiltrate were classified as lymphocytoid, plasmacytoid, immunoblastic (histocytic) and phagocytic. A number of elements partook of the ultrastructural features of two cell types and were considered to be intermediate froms (plasmacytoid lymphocytes, lymphocytoid immunoblasts, and plasmacytoid immunoblasts). It is believed that the various cell elements from part of a wide spectrum in which transformation of cell types takes place by maturation. This suggests an immunologic process as the main pathogenetic factor in the development of LG.

Meningioma and intracranial hemangiopericytoma

SummaryElectron microscopic study of 2 intracranial hemangiopericytomas and 7 meningiomas revealed fundamental morphologic differences between the 2 neoplasms. The most significant finding in hemangiopericytoma was the presence of ultrastructure features suggesting leiomyoblastic differentiation. These included characteristic fusiform intracytoplasmic and submembranous dense bodies, abundant cytoplasmic filaments, elongated cells with blunt-ended nuclei and juxtanuclear polarization of organelles. This observation is considered highly significant as an indicator of the pericytic nature of this tumor. In addition, hemangiopericytoma cells sometimes were arranged in spirals around pools of basement membrane-like material, perhaps a manifestation of the biologic capability of the cells to synthetize such material. Meningioma cells displayed as their main feature an ability to produce surface membrane specializations including interdigitations, desmosomes, zonulae adhaerentes and gap junctions. Sometimes the last 3 elements were linearly juxtaposed forming junctional complexes similar to those seen in certain epithelia. It is suggested that the characteristic whorls of meningioma are the result of cell interconnections arising from the specialized junctional attachments. Thus the distinctive morphology of the 2 neoplasms appears to derive from basic biologic properties of their elements.

Intracytoplasmic neuronal inclusions in the human thalamus

SummaryIntracytoplasmic cosinophilic inclusions were found by light microscopy in the thalamic neurons of 35 consecutive normal adult brains and in a case of myotonic dystrophy, but not in six newborn children, including one with myotonic dystrophy. Histochemical tests suggested a protein composition. Ultrastructurally, the inclusions were composed of stacks of parallel alternating dark and light rectilinear profiles not surrounded by a limiting membrane. Such inclusions are a virtually constant finding in the adult human thalamus and probably represent sites of neuronal protein storage.

Mixed Capillary Hemangioblastoma and Glioma

The histopathologic features of four cases of mixed capillary hemangioblastoma and glioma are described. In three cases, two of which arose in the cerebellum and one in the spinal cord, the hemangioblastic component may have originated from a neoplastic proliferation of the exuberant vascular stroma in a glial tumor. In a fourth case, a cerebellar hemangioblastoma was surrounded by a peripheral rim of atypical neoplastic-looking astrocytes (“reactive glioma”). The controversial concept of the “angioglioma” is reviewed, and it is proposed that the term be used to designate only true mixed tumors of glial and vascular tissue origin whose histologic features conform to the examples described in this report.

Periodic units in the intracristal and envelope spaces of neuronal mitochondria

SummaryUltrastructural study of the cerebral cortex and spinal anterior horns disclosed periodically repeating processes located in the envelope space or in the intracristal space of neuronal mitochondria. The alteration was observed in postmortem cases in which fixation was delayed either voluntarity or involuntarily, but was not present in postmortem or surgical specimens in which fixation was prompt. The change is interpreted as an artifact due to delayed fixation.

Malignant meningioma: ultrastructure and observations on histogenesis

Summary A malignant meningioma was studied by light and electron microscopy. Histologically, the tumour was composed predominantly of spindle shaped cells arranged in interlacing bundles with numerous mitoses and much nuclear atypia. There were many necrotic foci as well as invasion of the cerebral cortex, dura mater and blood vessels. Ultrastructurally, the main findings included moderate plasma membrane interdigitation, many intracytoplasmic filaments, and junctional attachments of three kinds: desmosomes, hemidesmosomes, and zonulae adhaerentes. These subcellular features are suggestive of arachnoidal cell origin.

Aspergilosis En Colombia

Se presentan 15 casos de aspergilosis recolectados en diferentes ciudades del país. Doce fueron casos autopsiados. Los tres restantes se refieren a pacientes en quienes se efectuó una lobectomía pulmonar superior derecha por aspergiloma gigante intracavitario. En los doce primeros existía una enfermedad básica que había alterado seriamente el estado general del paciente; once de ellos habían recibido antibióticos, cinco habían recibido esteroides, y dos, agentes citotóxicos. Se cree que, tanto el estado general del paciente, como la administración de dichas drogas, favorecieron la infección micótica. De los tres casos con aspergiloma intracavitario gigante, se cree que, en uno, la micosis se implantó en una caverna tuberculosa cicatrizada. En los otros dos, la cavidad era un bronquio localmente dilatado y se consideró que no existía una infección tuberculosa. ElAspergillus posee un amplio espectro de patogenicidad. Se le puede observar en lesiones que van desde una localización intrabronquial, acompañada de mínima o nula reacción inflamatoria, hasta casos en los cuales existen lesiones pulmonares necrotizantes con diseminación hematógena a otros órganos (sistema nervioso central, hígado, riñón).

In the Heart of the Beat: The Poetry of Rap by Alexs Pate

Poulenc actually wrote two early sonatas for violin and piano, but the composer discarded them both. The third and only extant sonata (19423) was dedicated to the persecuted Spanish writer Federico Garcia Lorca (1899–1936), who was killed during the Spanish Civil War. The sonata was written for and premiered by violinist Ginette Neveu (1919–49). It is a turbulent work, composed at the height of conflict during World War II; dark and jagged passages alternate with more lyrical sections. Celebrated performances during Poulenc’s lifetime included those by violinists Arthur Grumiaux and Yehudi Menuhin, but there are relatively few modern recordings of this sonata, possibly due to its sheer technical difficulties and overall dark tone. He and Sioles excel both technically and musically in this work; this is by far the best performance on the disc, and their interpretation is a welcome addition to the Poulenc discography. Overall, the ensemble playing in French Sonatas for Violin & Piano is excellent; obviously the two performers have worked together often as colleagues at LSU. He’s intonation is good, and he generally produces a beautiful tone from the violin, even in the strident, virtuosic passages of the Ravel and Poulenc works. Sioles’s piano playing is consistently solid and precise throughout all of the works on the disc. Unfortunately for both performers, the piano sounds like it was pushed way too far to the background in this recording, causing some passages with the violin to be unbalanced and indistinct. Conversely, the microphone seems to have been placed too close to the violin, so much so that one can often hear the slap of the left-hand fingers against the fingerboard. Even with these minor sonic deficiencies in the recording, this collaboration between violinist Lin He and pianist Gregory Sioles is a fine addition to the catalogue of recordings currently available for these works.