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Biomedical subjects

E R Laws

Publications and source records attributed to E R Laws.

At least 181 records · Page 10Linked to original sources
PubMed1986

Incidence and effectiveness of cerebrospinal fluid shunts in Olmsted County, Minnesota, 1956-1981.

In the period 1956 through 1981, 129 cerebrospinal fluid (CSF) shunt operations were performed on 50 patients who were residents of Olmsted County, Minn. The overall average annual age- and sex-adjusted incidence of initial CSF shunts during this 26-year period was 2.3 per 100,000 person-years. Within 5-year calendar time intervals, the average annual incidence rates per 100,000 person-years ranged from 0.8 (1956-1960) to 4.6 (1971-1975). There were 4 shunt-related deaths, 1 due to a CSF shunt infection and 3 due to acute increases in intracranial pressure. In this analysis of shunt procedures in a defined population, the diagnostic indications and changes over time in CSF shunting devices are also described.

Adolescent↗
PubMed1986

Hematoporphyrin derivative photocytotoxicity of human glioblastoma in cell culture.

The parameters of hematoporphyrin-derivative (HpD) photocytotoxicity of human glioma cells in cell culture were studied to determine the optimum wavelength and power density of light, to investigate the influence of tissue oxygenation, and to evaluate the role of singlet oxygen and free radicals in producing cell death. Cell survival curves demonstrated a relative killing efficiency of 12:1 for violet compared to red light. Eighty joules of red light were required to produce 100% cell kill at an HpD concentration of 10 micrograms/ml, a level of HpD that has been quantitated in biopsies from patients receiving HpD photoradiation therapy. No difference in cellular killing efficiency was observed for power densities of red light varying from 10 to 100 mW/cm2. Cytotoxicity was directly related to O2 tension from 12 to 490 torr with a slight but consistent increase in cell kill at O2 tensions from 7 to 12 torr. Cytotoxicity was effectively quenched by beta-carotene, whereas mannitol had no effect, indicating that cytotoxicity is probably mediated via a mechanism involving singlet oxygen. This information may serve as a basis for more effective application of HpD photoradiation therapy and for designing protocols to study the efficacy of such therapy.

Cell Line↗
PubMed1986

Temporal lobectomy in children with epilepsy.

The results of temporal lobectomy for medically refractory seizures are analyzed in 29 boys and 21 girls with a mean age of 15.8 years. The average age at onset of seizures was 7.5 years, and the time between onset and surgery averaged 8.3 years. Postoperatively, 27 patients (54%) were seizure-free, 12 patients (24%) had only occasional auras without loss of consciousness, five patients (10%) had fewer seizures, and six (12%) were unchanged. Therefore, 78% were essentially seizure-free and 88% benefited significantly from the operation. There was no significant change in the Wechsler Intelligence Scale scores before and after surgery; however, the shorter the time between seizure onset and surgery, the greater the likelihood of improvement in verbal and perceptual intelligence quotient. Social outcome was significantly improved, and a large percentage of patients were either in school or actively employed. Early consideration of temporal lobectomy in children with medically refractory seizures is recommended.

Adolescent↗
PubMed1986

The occurrence of dural invasion in pituitary adenomas.

This report describes 60 dural specimens from patients with pituitary adenomas treated by transsphenoidal microsurgery, and attempts to define more precisely the clinical and pathological correlation of microscopic dural invasion. Analysis of the adenomas was based on four characteristics; size, surgical invasiveness (based on the surgeon's assessment of involvement by tumor of bone, dura, or cavernous sinus), histological evidence of invasion, and immunohistochemical staining characteristics. The incidence of surgical invasiveness (24 cases, 40%) was greater than previously reported, but most important was the frequent occurrence of microscopic dural invasion (51 cases, 85%). There was a clear progression of microscopic evidence of dural invasion with increasing tumor size: 69%, 88%, and 94% of the dural specimens from microadenomas, macroadenomas, and tumors with suprasellar extension, respectively, showed microscopic dural invasion. A correlation of invasiveness with immunohistochemical classification of tumor type was not evident.

Adenoma↗
PubMed1986

Clip-grafts in microvascular decompression of the posterior fossa. Technical note.

A method is described for the protection of the trigeminal root from recurrent vascular irritation or compression after posterior fossa microvascular decompression. A vascular clip-graft, using a Sundt clip of suitable size, is applied to the sensory root of the trigeminal nerve. The technique has proven safe and effective in a series of nine patients followed for up to 28 months.

Aged↗
PubMed1986

Long-term results in transsphenoidal removal of nonfunctioning pituitary adenomas.

Little has been written about the long-term results of transsphenoidal treatment for clinically nonfunctioning pituitary adenomas. The records of 100 patients who had undergone a transsphenoidal procedure for excision of such tumors were reviewed. Immunocytology for pituitary hormones was performed in all cases. The group consisted predominantly of null-cell adenomas, although a small number of prolactinomas and gonadotropic tumors were found. The mean diameter of the tumors at the time of detection was slightly more than 2 cm. In most cases, the presenting symptoms were due to the mass effect of the tumor (that is, visual symptoms in 72 patients, hypopituitarism in 61, headache in 36, and cranial nerve disturbance other than visual loss in 10). Radiation therapy was recommended for patients in whom subtotal removal of the adenoma was expected. Six patients developed symptomatic tumor recurrence, and 10 patients demonstrated radiographic recurrence during the 48 to 100 months (mean 73.4 months) of follow-up observation. Only three of 10 deaths during the follow-up period were due to pituitary disease or treatment.

Adenoma↗
PubMed1986

Pathology of invasive pituitary tumors with special reference to functional classification.

Pituitary adenomas may remain intrasellar or infiltrate dura and bone. Invasive adenomas are not considered to be malignant; in biological behavior they are between non-infiltrative adenomas and pituitary carcinomas. The latter are defined as tumors with subarachnoid, brain, or systemic metastasis. Invasion may be defined radiologically, operatively, or histologically. On the basis of operatively assessed tumor size and gross invasion of dura and bone as well as immunocytochemical and ultrastructural analysis of 365 pituitary adenomas, the following data were obtained. There were 23 growth hormone (GH)-cell adenomas: 14% microadenomas and 86% macroadenomas; their overall frequency of invasion was 50%. There were 24 prolactin (PRL)-cell adenomas: 33% microadenomas and 67% macroadenomas, with an overall frequency of invasion of 52%. Mixed GH-cell and PRL-cell adenomas were found in 35 cases; 26% were microadenomas and 74% were macroadenomas, and the overall frequency of invasion was 31%. Sixty patients had adrenocorticotropic hormone (ACTH)-cell adenomas (Cushing's disease): 87% microadenomas and 13% macroadenomas; the overall frequency of invasion was 25% (in 8% of microadenomas and 62% of macroadenomas). Twenty patients had ACTH-cell adenomas (Nelson's syndrome): 30% microadenomas and 70% macroadenomas; the overall frequency of invasion in these cases was 50% (in 17% of microadenomas and 64% of macroadenomas). Silent ACTH-cell adenomas, 100% macroadenomas, were found in 11 patients, with an 82% frequency of invasion. There were 32 follicle-stimulating and luteinizing hormone adenomas, all macroadenomas, with a frequency of invasion of 21%. Four patients had thyroid-stimulating hormone adenomas, all macroadenomas, with a 75% frequency of invasion. Null-cell adenomas were found in 93 cases: 2% microadenomas and 98% macroadenomas, with a frequency of invasion of 42%. There were 63 plurihormonal adenomas (GH, PRL, glycoprotein): 25% microadenomas and 75% macroadenomas, with a 50% overall frequency of invasion. Based on this study, and on their usual frequency of occurrence, the estimated rate of gross invasion by pituitary adenomas of all types is approximately 35%. It is concluded that immunocytochemical and ultrastructural characteristics of pituitary adenomas reflect the tendency of these tumors to infiltrate and hence may be of prognostic significance.

Adenoma↗
PubMed1986

Plurihormonal pituitary adenomas.

Plurihormonal adenomas of the pituitary, ie, tumors that engage in the production of unusual combinations of hormones, represent approximately 10% to 15% of all adenomas. Such tumors comprise in excess of 50% of adenomas in the setting of acromegaly and occur with somewhat greater frequency in childhood and adolescence than in adulthood. Eight percent are associated with multiple endocrine neoplasia, type I. The most common variant of plurihormonal adenoma produces growth hormone, prolactin, and one or more glycoprotein hormones, the most common being TSH. Clinical effects most often reflect the presence of growth hormone, and to a lesser extent, prolactin cells; expression of glycoprotein hormone production is rare. The tumors are more often macroadenomas (80%) than microadenomas (20%) and demonstrate gross invasion in 50% of cases. Plurihormonal adenomas may be ultrastructurally monomorphous, bimorphous, or trimorphous; thus, one morphologic cell type may elaborate several hormones.

Adenoma↗
PubMed1986

Meningio-angiomatosis: a report of six cases with special reference to the occurrence of neurofibrillary tangles.

We report six cases of meningio-angiomatosis, a disorder of the cerebral cortex of probable malformative origin frequently associated with neurofibromatosis and either asymptomatic or associated with a seizure disorder. The patients, three males and three females, ranged from 10 to 70 years of age at diagnosis. The lesion was an incidental autopsy finding in two patients; four subjects had a seizure disorder which improved following surgical resection of the cortical lesion. In five instances the process was unifocal; one patient with neurofibromatosis had multifocal involvement. Grossly, the lesions were firm, sharply demarcated, transcortical plaques with leptomeningeal calcifications in five cases. The cortical plaques showed characteristic features of meningio-angiomatosis, i.e. a circumscribed, proliferating microvasculature with perivascular meningothelial cell proliferation and fibrosis. In five cases Alzheimer's neurofibrillary change in neurons was present both within the plaques and in the surrounding cortex. Neither senile plaques nor granulovacuolar degeneration were noted. Electron microscopy in one case demonstrated typical intraneuronal accumulations of neurofilaments with regular constrictions. Intracortical vessels lined by endothelial cells with tight junctions were surrounded by pericytes and meningothelial cells. The significance of neurofibrillary tangles described in a variety of disorders, and the factors stimulating their production in the present cases are unknown.

Adolescent↗
PubMed1986

Development of experimental models for meningeal neoplasia using intrathecal injection of 9L gliosarcoma and Walker 256 carcinosarcoma in the rat.

Two models for meningeal neoplasia have been developed in rats using intrathecal injection of 9L gliosarcoma and Walker 256 carcinosarcoma cells. Tumor cells were injected in unanesthetized animals through an indwelling catheter inserted at the cisterna magna to the level of the lumbar enlargement of the spinal cord. Survival of rats was dependent on the number of tumor cells injected. Spread of tumor was quantified by histology using a grading scale, and functional and behavioral changes were measured. Rats injected with 10(6) 9L gliosarcoma cells showed progressive weight loss, flaccid paralysis, and neurogenic bladder dysfunction and had a median survival of 11 days. The tumor frequently grew as a mass compressing the spinal cord. The 9L gliosarcoma tumor cells markedly invaded the Virchow-Robin spaces but exhibited only minimal invasion of the central nervous system parenchyma. The tumor reached the brain by day 10. Rats injected with 2 X 10(5) Walker 256 carcinosarcoma cells showed progressive weight loss and weakness and had a median survival of 6 days. The tumor grew within the leptomeninges in a discontinuous multifocal fashion and reached the brain by day 4. There was extensive invasion of the central nervous system parenchyma by Walker 256 tumor cells along the Virchow-Robin spaces resulting in hemorrhage and necrosis of grey and white matter. Hot plate and tail flick response times were significantly delayed only in the days immediately preceding death of animals with either 9L or Walker 256 tumor and were not good indicators of tumor progression. Loss of motor coordination and failure of the stepping and placing reflex on the other hand showed good correlation with spread of tumor measured histologically. Control animals injected with 0.9% NaCl or with lethally irradiated tumor cells showed no significant weight loss or functional or behavioral changes. The intrathecal 9L gliosarcoma and Walker 256 carcinosarcoma models show different characteristics of human meningeal carcinomatosis and will be used for studies of experimental chemotherapy with intrathecally administered antitumor drugs.

Animals↗
PubMed1985

Prolactin cell carcinoma of the pituitary. Clinicopathologic, immunohistochemical, and ultrastructural study of a case with cranial and extracranial metastases.

A patient with a primary adenohypophyseal neoplasm who had a long course marked by multiple surgical resections, radiation therapy, and high-dose dopamine agonist therapy developed local invasion as well as cranial and extracranial osseous metastatic lesions. The serum prolactin levels were greatly elevated, and immunohistochemical studies demonstrated prolactin in the cytoplasm of primary and metastatic tumor cells. Ultrastructural features of lactotrophic differentiation, including misplaced granule exocytosis, were observed. This is the third reported case of prolactin cell carcinoma that metastasized despite high-dose dopamine agonist therapy. Analysis of the patient's serum prolactin showed no abnormality in the chromatographic profile of biologic activity.

Biological Assay↗
PubMed1985

Multidisciplinary management of acromegaly and its deformities.

The skeletal deformities associated with acromegaly are not reversed by correction of abnormal growth hormone dynamic. We describe a patient with acromegaly in whom facial reconstruction was undertaken after successful removal of a pituitary adenoma.

Acromegaly↗
PubMed1985

Pituitary adenomas associated with hyperprolactinemia: a clinical and immunohistochemical study of 97 patients operated on transsphenoidally.

Immunohistochemical studies were performed on the tumors of 97 of 100 patients who had undergone an operation for a presumed prolactin-secreting pituitary adenoma; no tissue was available for study in the other 3 patients. Appropriate immunohistochemical studies were done to identify the presence of growth hormone, prolactin, adrenocorticotropic hormone, luteinizing hormone, follicle-stimulating hormone, and thyroid-stimulating hormone within the adenoma cells. The presence of a prolactin-producing pituitary adenoma was confirmed in 91 patients, 3 of whom had an adenoma that consisted of cells that contained prolactin and growth hormone. One other patient, not counted among the 91 with prolactinoma, had lactotrope and thyrotrope hyperplasia. Among the five patients whose adenoma did not contain prolactin cells, four had a null cell adenoma and one had a tumor consisting of follicle-stimulating hormone and luteinizing hormone immunoreactive cells. On the basis of preoperative serum prolactin values in these patients, we concluded that moderately increased values (30 to 200 ng/ml) of serum prolactin are not a reliable guide for determining whether a prolactin-producing pituitary adenoma is present, whereas levels exceeding 200 ng/ml are usually associated with a prolactin-secreting tumor.

Adenoma↗
PubMed1985

Human phenol sulfotransferase: correlation of brain and platelet activities.

Phenol sulfotransferase (PST; EC 2.8.2.1) catalyzes the sulfate conjugation of phenolic and catechol neurotransmitters and drugs. The human blood platelet has been the most thoroughly studied source of PST because of the possibility that the regulation of the enzyme in this easily accessible tissue might reflect the regulation of PST in the CNS. The human brain and platelet contain at least two forms of PST, forms designated as thermostable (TS) and thermolabile (TL) PST. TS PST catalyzes the sulfate conjugation of micromolar concentrations of phenol and p-nitrophenol and TL PST catalyzes the sulfate conjugation of dopamine and other monoamines. This study was performed to determine whether individual variations in the activities of human platelet TS and TL PST reflect individual variations in cerebral cortical PST activities. PST activities were measured in platelets and in cerebral cortical tissue obtained from 15 patients with epilepsy during clinically indicated neurosurgery. There was a highly significant correlation between the activities of the TS form of PST in cerebral cortex and platelets of these patients (r = 0.940, p less than 0.001), but there was not a significant correlation between activities of the TL form of PST in the two tissues (r = 0.396, p greater than 0.14). In addition to variations in the level of enzyme activity, there are also wide individual variations in the thermal stability of platelet TS PST.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Meningiomas of the cerebellopontine angle.

The majority of cerebellopontine angle tumors are acoustic neurinomas; however, 10% to 15% are meningiomas. Meningiomas are benign lesions that must be removed but may require surgical approaches different from those used for acoustic neurinomas. To determine if meningiomas could be distinguished from acoustic neurinomas clinically, findings in 20 patients who underwent removal of a meningioma were compared to those in 131 patients who had an acoustic neurinoma removed during the same period. We found that in patients with meningiomas the tumors frequently are large at presentation, the otologic symptoms and audiometric findings are less dramatic, and roentgenograms of the skull and tomograms of the petrous apex rarely show erosion of the internal auditory canal. Computerized tomography is the most useful method for differentiating a meningioma from a neurinoma: when a meningioma is present the characteristic finding is a broad-based mass aligned with the petrous ridge, not centered over the internal auditory canal.

Adolescent↗
PubMed1985

Surgical treatment of idiopathic hydrocephalus in elderly patients.

We studied 45 adult patients with idiopathic hydrocephalus who had undergone a shunting procedure at the Mayo Clinic during a 16-year period. The follow-up period extended up to 157 months. Thirty-four of the 45 patients (75%) improved at some time after the operation, and 19 (42%) experienced continuous improvement. The median duration of improvement was 24 months. Patients who had symptoms for less than 2 years were most likely to improve. CT played an important role in the diagnosis and follow-up, but ventricular size or degree of atrophy did not correlate with response.

Aged↗
PubMed1985

Spontaneous cerebrospinal fluid rhinorrhea: evolving concepts in diagnosis and surgical management based on the Mayo Clinic experience from 1970 through 1981.

Spontaneous cerebrospinal fluid (CSF) rhinorrhea, occurring in the absence of recent trauma, is a distinct clinical entity that can be difficult to diagnose and treat. The case records of 28 patients with this entity were reviewed retrospectively. Pertinent historical data and the results of radiographic evaluation are discussed. The patients were classified into one of three major etiological categories: congenital anomaly, delayed posttraumatic, and tumor groups. The fistulas causing the rhinorrhea were approached extracranially or intracranially, depending on the suspected cause and location. A cure was obtained in 22 of the 27 patients surgically treated (81%). Seventeen patients were cured by a single operation, 5 were cured after multiple operations, and 5 continued to leak despite surgical treatment. Three of the 5 patients who were surgical failures had intracranial tumors, and 2 of them died from complications of persistent fistulas. With the use of a multidisciplinary team approach, an extracranial operation (transethmoidal or transsphenoidal) to repair a spontaneous CSF leak offers a high success rate and is associated with minimal morbidity in appropriately selected patients.

Adolescent↗