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Biomedical subjects

H M Zimmerman

Publications and source records attributed to H M Zimmerman.

At least 19 recordsLinked to original sources
PubMed1986

The effect of verapamil on pancreatic exocrine secretion.

This study set out to examine the effects of a Ca++ channel blocker, verapamil, on pancreatic exocrine secretion because of the known relationship between amylase secretion and intracellular Ca++. Pancreatic secretion was stimulated in dogs by infusing secretin and cholecystokinin. Verapamil was found to inhibit the secretion of amylase but to have no effect on lipase, trypsin, or total protein. There was no effect on the secretion of water and bicarbonate. To determine the possible physiologic significance of these findings, the pancreas was stimulated by a meat meal, and verapamil was found to inhibit amylase secretion again and in addition to inhibit the secretion of water and bicarbonate. The results suggest that verapamil has an inhibitory effect on amylase secretion by blocking the influx of Ca++ into the acinar cell and has an indirect effect leading to inhibition of water and bicarbonate secretion from the duct cells.

Amylases↗
PubMed1985

Cerebral glioblastomas can be cured!

In 1959, a 30-year-old man underwent the removal of a glioblastoma multiforme from the right parietal lobe of his brain. After the operation, he received x-ray therapy. He made a complete recovery. Today, over 25 years later, he is alive and well and is regularly employed full-time. If glioblastomas and other cerebral gliomas are removed completely, the patients can be cured of their tumors.

Adult↗
PubMed1978

Fine structure of a cerebellar neuroblastoma.

A cerebellar neoplasm of an 18-month-old boy was examined with both the light and electron microscopes. The diagnosis of neuroblastoma was made on the basis of the presence of numerous synaptic vesicles in the great majority of cell processes and the occasional complete synapses within the tumor tissue.

Cerebellar Neoplasms↗
PubMed1977

Dense intracranial epidermoid tumors. Computed tomographic observations.

Three extra-axial posterior fossa epidermoid tumors manifested nearly identical CT appearance of large size, sharp margination, apparently homogeneously increased attenuation in the range of 80-120 Hounsfield units, and absence of contrast-agent enhancement. This constellation of findings is distinctly different from that reported previously, and appears to be characteristic for some epidermoid tumors.

Adolescent↗
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↗