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J B Posner

Publications and source records attributed to J B Posner.

At least 19 recordsLinked to original sources
PubMed1992

Anti-Hu--associated paraneoplastic encephalomyelitis/sensory neuronopathy. A clinical study of 71 patients.

We studied 71 patients with "paraneoplastic" encephalomyelitis, sensory neuronopathy, or both associated with the presence of the anti-Hu antibody in their serum. Most (78%) had small-cell lung cancer. In 9 patients no tumor was detected. Fifty-two patients (73%) had signs and symptoms of multifocal involvement of the nervous system; in 28 (39%), 2 areas, and in 24 (34%), 3 or more areas were clinically affected. Sensory neuronopathy was present in 52 patients (74%), but in only 44 (62%) did it dominate the course of the disease. Other predominant findings were: motor neuron dysfunction (14 patients, 20%), limbic encephalopathy (14, 20%), cerebellar symptoms (11, 15%), brainstem encephalopathy (10, 14%), and autonomic nervous system dysfunction (7, 10%). The presence of the anti-Hu antibody prompted a search for the tumor in 60% of the patients; the tumor when found was usually small and remained localized until death, or was demonstrated only at autopsy. Treatment using steroids and plasmapheresis, immunosuppressants, or both, did not improve the paraneoplastic symptoms. Autonomic and respiratory failure, either of central origin or secondary to neuromuscular weakness, were the principal causes of death. Patients with rapidly developing sensory neuropathy or symptoms of encephalomyelitis should be studied for the presence of the anti-Hu antibody; if the antibody is found, the possibility of small-cell lung cancer should be investigated. If a tumor is not found in the initial search, one may become evident in several months.

Adolescent↗
PubMed1992

Pathogenesis of central nervous system paraneoplastic syndromes.

The pathogenesis of central nervous system paraneoplastic syndromes has not been established. Increasing evidence supports the hypothesis that CNS paraneoplastic syndromes are immune disorders arising from an immune response to the underlying neoplasm. The hypothesis is that antigens or epitopes shared between the tumor and the nervous system are recognized as foreign by the host and elicit an immune response. The immune response is directed appropriately against the tumor leading to a more indolent course in those patients with paraneoplastic syndromes but is misdirected against the nervous system often leading to severe nervous system destruction. The evidence for this hypothesis consists of: 1) The finding of high titer autoantibodies that react with antigens in both tumor and central nervous system. 2) Intrathecal synthesis of the antibody. 3) The presence of the antibody in the central nervous system at autopsy. The development of animal models will be required to determine the exact nature of the pathogenesis of these disorders.

Autoantibodies↗
PubMed1979

Subacute motor neuronopathy: a remote effect of lymphoma.

Ten patients developed a subacute lower motor neuron syndrome as a remote effect of Hodgkin's disease or other lymphoma. The illness usually followed a benign course independent of the activity of the underlying neoplasm. Seven of the patients improved spontaneously, and 3 became neurologically normal. Two patients died of intercurrent infections related to immunosuppression. Neuropathological examination of these 2 patients and 3 previously reported cases showed prominent neuronal degeneration restricted to the anterior horns of the spinal cord and mild posterior column demyelination. Demyelination was also present in the anterior roots of our autopsied patients and was accompanied by large, hyperchromatic Schwann cells. The cause of the illness is obscure, but both radiation therapy and opportunistic infection may be contributing factors. Attempts at virus isolation have been unsuccessful. The syndrome should be distinguished from the more common direct effects of lymphoma on the nervous system, since its identification spares the patient additional, potentially harmful therapy.

Adult↗
PubMed1979

beta-Endorphin: analgesic and hormonal effects in humans.

The pharmacokinetics and the hormonal, analgesic, and behavioral effects of several doses of human beta-endorphin were evaluated after intravenous administration to three patients and intracerebroventricular administration to one patient with pain caused by cancer. These effects were compared to the hormonal effects of intravenously administered morphine sulfate in two patients and an enkephalin analog in two baboons. The mean terminal half-life after intravenous administration of 5 or 10 mg of human beta-endorphin to three patients was 37 min; the mean volume of distribution was 178 ml/kg, and the metabolic clearance rate was 3.2 (ml/min)/kg. The half-life of beta-endorphin in cerebrospinal fluid after intracerebroventricular administration was 93 min, and the volume of distribution was 0.74 ml/kg. A rapid rise in plasma prolactin followed both intravenous and intracerebroventricular beta-endorphin. Intravenous administration did not affect plasma growth hormone, but intracerebroventricular administration suppressed plasma growth hormone. No significant change in plasma growth hormone was noted after intravenous administration of morphine to humans, but plasma growth hormone decreased in one baboon after administration of the enkephalin analog. beta-Endorphin-stimulated release of prolactin occurred at doses lower than those required to produce analgesic and other behavioral effects. When both hormonal and analgesic effects were observed (after 7.5 mg were given intracerebroventricularly), the onset of the hormonal response slightly preceded the analgesic and behavioral responses. These studies suggest that the hormonal effects of beta-endorphin are species dependent and are similar to those of morphine. Hormonal and analgesic effects of beta-endorphin appear to result from the activation of opiate receptors that differ in their locations and characteristics.

Adult↗
PubMed1979

Human brain tumor transplantation into nude mice.

Seven human brain tumors were transplanted into the brains (6/7 takes) and subcutaneous tissues (7/7 takes) of athymic nude mice. Compared to experimental animal brain tumors, these tumors, taken directly from patients in the operating room and transplanted, grew more slowly in the mice; their growth rates following explant generally paralleled those in the patients. A rough correlation was seen between the degree of the tumor's malignancy and both successful take and rate of growth following explant. The tumors' growth rates increased during serial transplantation after explant. Two tumors developed into long-term serial lines; both came from gliosarcomas. Preliminary chemotherapy experiments with these two lines demonstrated different chemosensitivities. One line was very sensitive to the nitrosoureas and resistant to procarbazine; the other line was more sensitive to procarbazine than to the nitrosoureas. This model permits study of the biologic behavior of human brain tumors growing intracerebrally and subcutaneously in nude mice.

Animals↗
PubMed1979

Malignant cells in cerebrospinal fluid (CSF): the meaning of a positive CSF cytology.

We reviewed the correlation between malignant cells in cerebrospinal fluid (CSF) (positive cytology) and pathologic findings at autopsy. The purpose was to discover: (1) the incidence of negative CSF cytology in patients with CNS malignancy, (2) the incidence of false-positive cytology, and (3) the relationship between a true-positive cytology and the distribution of malignant tumor at autopsy. Of 117 patients with CNS tumor and premortem cytologic examination of the CSF, 31 (26 percent) were positive and 86 (74 percent) were negative. Only 1 of 66 patients with tumor that did not reach the leptomeninges had a positive cytology. Of 51 patients with leptomeningeal tumor at autopsy, cytology was positive in 30 (59 percent) and negative in 21 (41 percent). Five potentially "false-positive" cytologies were encountered: three patients were treated, and tumor may have been eradicated; in two patients with lymphoma, inflammatory cells associated with infection were apparently mistaken for malignant cells. These data indicate that a positive CSF cytology is a reliable indicator of CNS malignancy and almost always reflects leptomeningeal tumor.

Brain Neoplasms↗
PubMed1979

Nonmetastatic superior sagittal sinus thrombosis complicating systemic cancer.

Seven patients with cancer complicated by nonmetastatic sagittal sinus thrombosis were encountered in a 7-year period. Five had hematologic malignancies and two had solid tumors. There were two different presentations. In the first, neurologic signs and symptoms (e.g., headaches, seizures, hemiparesis, lethargy) occurred suddenly in five patients shortly after initiation of cancer therapy. Four of these five patients recovered with minimal residua; the fifth died as a direct result of the sinus thrombosis. The second presentation occurred in the two patients with terminal cancer who declined gradually without focal signs; both patients died. Only arteriography can reliably establish the diagnosis of sagittal sinus occlusion. In patients with cancer, sagittal sinus occlusion probably results from a "hypercoagulable state" associated with the systemic neoplasm.

Adenocarcinoma↗
PubMed1979

Sterilization of cerebral metastases by radiation therapy.

It is generally acknowledged that radiation therapy (RT) provides effective palliative treatment for the majority of patients with brain metastases. It is less well known that RT can be "curative." In 10 years, we examined five patients with brain metastases treated with whole-brain radiotherapy and with no residual tumor in the brain at autopsy. These five patients represented about 3 percent (5 of 187) of patients treated for brain metastases and later examined at autopsy. Some metastatic brain tumors are eradicated by RT, and all nonterminal patients should be offered such treatment.

Adenocarcinoma↗
PubMed1979

Enhancement of CNS penetration of methotrexate by hyperosmolar intracarotid mannitol or carcinomatous meningitis.

Intracarotid (i.c.) hyperosmolar mannitol enhances central nervous system (CNS) penetration of intravenous (i.v.) methotrexate (MTX) in normal adult rats. A fivefold augmentation in the CSF:serum and ipsilateral brain:serum MTX concentration ratios was observed 1 hour after drug administration. Intravenous mannitol had no such effect. Rats with meningeal carcinomatosis have a partial defect in blood-brain barrier function, and the CSF:serum MTX concentration ratio was 4.6 times higher in these animals than in normal rats prior to mannitol therapy. Intracarotid hyperosmolar mannitol further augmented the blood-brain barrier permeability to intravenous MTX. Intracarotid mannitol increased the therapeutic effect of MTX, since rats with meningeal carcinomatosis that received i.v. MTX and i.c. mannitol experienced a slight enhancement in survival.

Animals↗
PubMed1978

Epidural spinal cord compression from metastatic tumor: diagnosis and treatment.

The clinical findings in 130 conseucutive cases of spinal cord compression by metastatic extradural tumors were analyzed. These 130 patients were combined with a previous survey of 105 patients to compare the effectiveness of radiation therapy (RT) alone with that of surgical decompression followed by RT. Ambulation after treatment was considered a successful outcome. The most common primary tumors producing spinal cord compression were (in order) breast, lung, prostate, and kidney. In 68% of these tumors the thoracic region was involved. Pain was the primary symptom of 96% of the patients, while motor or sensory deficits (or both) were found in 82% of them. Therapy consisted of surgery and RT in 65 patients and RT alone in 170 patients. There were no differences in outcome between those treated by surgery combined with RT and those managed by RT alone. Patients with radiosensitive tumors and those ambulatory at the onset of treatment benefited whether treated by surgery or by RT. Seventy-five percent of living patients who improved from treatment remained ambulatory at 6 months, and approximately 50% of living patients were ambulatory at 1 year. We conclude that RT without decompressive laminectomy is as effective as decompressive laminectomy in treating epidural spinal cord compression from systemic cancer.

Adolescent↗