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Biomedical subjects

H M Zimmerman

Publications and source records attributed to H M Zimmerman.

At least 37 records · Page 2Linked to original sources
PubMed1976

Vascular alterations in delayed radiation necrosis of the brain. An electron microscopical study.

A 51-year-old woman who had been given cobalt therapy for nasopharyngeal carcinoma was seen three years later with a mass in the left frontotemporal region of the brain. Biopsy specimen of the lesion showed the classic features of delayed radiation necrosis on light microscopy. In addition, several blood vessels showed endothelial cell proliferation. Transmission electron microscopical study demonstrated numerous alterations of the endothelial cell, such as intraluminal infoldings of the plasma membrane, an increased amount of cytoplasmic organelles, and the frequent occurrence of tubular bodies in addition to degenerative and reactive changes in the neuropil.

Blood Vessels↗
PubMed1975

Fine structure of intercellular junctions and blood vessels in medulloblastomas.

Six medulloblastomas were studied by electron microscopy. Two features were found which seem to be constant and essential characteristics of medulloblastoma. First, cell junctions are abundant between tumor cells. These are mostly desmosome-like but other, closer junctions, were also seen. Second, the capillary endothelia contain frequent tubular bodies and other inclusions which may be related to them.

Blood Vessels↗
PubMed1975

Malignant lymphomas of the nervous system.

In a series of some 7,000 patients with tumors of the central nervous system, 208 patients (about 3%) had some form of a malignant lymphoma. Slightly less than half of these tumors were primary in the brain; the remainder had cranial involvement as part of a generalized process. The tumors consisted of Hodgkin's disease, lymphosarcomas, reticulosarcomas and plasmacytomas. The brain was involved in one of two ways: either as localized tumor masses resembling certain gliomas, or as diffusely invasive neoplasms resembling exudative cellular inflammatory processes. They had a peculiar predilection for the septum pellucidum but occurred also in the cerebral lobes, basal ganglia, brain stem and cerebellum. They all produced a fibrillary stroma of reticulin fibers and they spread along the perivascular spaces, in the cerebrospinal subarachnoid space, or intraventricularly on and beneath the ependymal lining. One type of lymphoma often fused into another - thus a single tumor often consisted of Hodgkin's sarcoma, lymphosarcoma and reticulosarcoma. In an addition series of 57 cases of spinal cord involvement by malignant lymphomas, there were no instances of a primary tumor; all patients had either primary lymphomas of the brain with secondary spread to the spinal subarchnoid space, or had spinal cord compression as a result of tumor in the vertebrae, the spinal epidural space, or the spinal dura. Hence the spinal cord involvement was a secondary manifestation of a lymphoma elsewhere. Peripheral nerve involvement by lymphomas resulted in destruction of myelin sheaths and axons by tumor cell infiltration and the neuropathy was always part of a generalized lymphomatosis.

Brain Neoplasms↗
PubMed1975

[The fine structure of ependymona (author's transl)].

The tumor cells form an unoriented mass rather than a layered structure. Most of the cells have no ependymal specialization, such as cilia, microtubular, etc. Instead, they assume a primitive undifferentiated appearance with large nuclei and abundant free ribosomes. Occasionally, however, certain cells tend to form a ring around a narrow lumen-like space within the mass. Such spaces are virtually filled with microvilli and, occasionally, even cilia arising form the surrounding cells. Elaborate desmosomes decorate the apposing surfaces of such cells and basal bodies are presented within the cytoplasm. In addition, the tumor cells often display glial filaments, glycogen granules and microtubules, similar to the cells comprising astrocytomas. As is well known, astrocytomas and ependymomas are often found mixed in the same tumor.

Astrocytoma↗
PubMed1975

[The fine structure of epithelial cyst in the central nervous system (author's transl)].

The fine structure of three types of cysts within central nervous system, all with a single cell lining, has been examined. The first was in the subarachnoid space of the lumber cord and the lining cells included both ciliated and nonciliated secretory cells. It was considered to be of endodermal origin. The second type was a colloid cyst of the third ventricle and its fine structural features were almost identical to those of the first type. It was, therefore, likewise considered to be of endodermal origin. The third type was an intracerebral epithelial cyst in which the lining cells more closely resembled ependymal cells. The value of fine structural studies for the understanding of the pathogenesis of epithelial cysts within the central nervous system is discussed.

Brain Neoplasms↗