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Biomedical subjects

E R Laws

Publications and source records attributed to E R Laws.

At least 73 records · Page 4Linked to original sources
PubMed1998

Sulfonylurea receptor mRNA expression in pituitary macroadenomas.

ATP-sensitive K+ (KATP) channels modulated by sulfonylurea compounds have been previously identified in the anterior pituitary of the rat and have been demonstrated to influence GH release. Recently, a sulfonylurea receptor (SUR) has been cloned from an islet cell tumor and identified as a member of the ATP binding cassette superfamily capable to coupling with inwardly rectifying potassium channels. To determine if the same receptor is expressed in pituitary tumors, SUR mRNA levels were measured in 28 human macroadenoma specimens using an RNase protection assay. All immunonegative, corticotrophin (ACTH), growth hormone (GH), and GH/prolactin (GH/Prl) immunostaining tumors expressed detectable amounts of SUR message. Among these tumors, only the GH and GH/ Prl adenomas were functional. Of the tumors immunostaining for luteinizing hormone (LH), follicle-stimulating hormone (FSH), or both, SUR mRNA was present in small amounts in 5/11. Only 1/3 Prl immunostaining tumors contained SUR mRNA. In summary, we have demonstrated that SUR mRNA expression is common in several types of silent pituitary adenomas and in functional tumors that secrete GH. Lower levels are seen in some gonadotrophin immunostaining tumors.

ATP-Binding Cassette Transporters↗
PubMed1998

Factors associated with survival in patients with meningioma.

OBJECT: To explore factors affecting the survival rate in patients with meningiomas, the authors used the National Cancer Data Base (NCDB), which includes tumors from approximately 1000 hospitals participating in the American College of Surgeons tumor registry program. METHODS: Analysis included over 9000 cases diagnosed from 1985 to 1988 and 1990 to 1992. Survival estimates were computed and prognostic factors were identified using a proportional hazards model. The overall 5-year survival rate was 69% and it declined with patient age. This rate was 81% in patients aged 21 to 64 years and 56% for patients 65 years of age or older. When patients were grouped by the histological type of their tumors, those with benign tumors had an overall 5-year survival rate of 70%, whereas the overall 5-year survival rates in patients with atypical and malignant meningiomas were 75% and 55%, respectively. Prognostic factors for benign tumors included age at diagnosis, tumor size, whether treated surgically, hospital type, and radiation therapy; for malignant tumors, the prognostic factors included: age at diagnosis, whether treated surgically, and radiation therapy. These factors were statistically significant. The 5-year rate for recurrence of symptoms (regardless of the method of treatment) was 19.2% for those with benign tumors and 32.4% for those with malignant tumors. In patients whose benign tumor had been completely removed, the 5-year rate of tumor recurrence was 20.5%. CONCLUSIONS: Although not population-based, the NCDB has the potential for providing pertinent information regarding patient characteristics and methods of treatment for benign, as well as malignant, brain tumors.

Activities of Daily Living↗
PubMed1998

Symptomatic pituitary metastases.

OBJECT: The diagnosis and treatment of metastasis to the pituitary gland can be difficult to determine. The goal of this study was to analyze the clinical presentation, treatment, and prognosis of patients who presented with symptomatic pituitary metastasis. METHODS: The cases of 36 patients with symptomatic pituitary metastases were reviewed. The most common primary cancers were breast (33%) and lung (36%). The presenting symptoms included diabetes insipidus, anterior pituitary insufficiency, and retroorbital pain. The overall median length of patient survival following diagnosis of pituitary metastasis was 180 days. In 20 patients (56%), symptoms stemming from pituitary metastasis were the first manifestation of illness. Local control of tumor was associated with significant improvement in survival times (p < 0.05) and amelioration of disabling symptoms including painful ophthalmoplegia and visual field deficits. CONCLUSIONS: Aggressive treatment including both surgical decompression and radiation therapy improves the quality of life in patients suffering from symptomatic pituitary metastasis.

Adult↗
PubMed1998

A neurosurgical way of life. The 1998 presidential address.

The author provides a review of the relationship between Harvey Cushing and William Osler. Dr. Osler's influence on Cushing's role as a leader in neurosurgery is examined. Some basic principles of a neurosurgical "Way of Life" are reviewed.

History, 19th Century↗
PubMed1998

Primary fibrosarcoma of the sella unrelated to previous radiation therapy.

Fibrosarcomas involving the sella turcica are rare lesions and, when encountered, have been associated with previous radiation of a pituitary adenoma. Although primary intracranial fibrosarcomas are well recognized, no case of primary fibrosarcoma of the sella turcica has been reported to date. We describe here a patient who presented with a 2-month history of headache, visual disturbances, and diabetes insipidus. Her past medical history was unremarkable, with no radiation therapy. Magnetic resonance imaging revealed a sellar/suprasellar lesion that at surgery appeared firm in consistency. A radical removal of the mass was performed through a transsphenoidal approach. The patient recovered promptly from the operation and 2 weeks later, given the aggressive histologic appearance of the lesion, underwent gamma knife radiosurgery. Seven months after diagnosis, the patient presented with local tumor recurrence. A subtotal surgical resection was performed, and additional postsurgical treatment is still under consideration. Although most often related to previous radiation of the pituitary gland, primary fibrosarcomas can occur in the sella. This possibility should be suspected in the differential diagnosis of sellar masses that lack the classical characteristics of the much more common pituitary adenomas.

Diagnosis, Differential↗
PubMed1997

Referral guidelines: carpal tunnel syndrome.

The contribution on the postoperative management and rehabilitation of patients with carpal tunnel syndrome should be carefully considered by every surgeon. The operation is simply not over when the last stitch goes in; careful postoperative management is quite important if one is to obtain optimal surgical results. The principles outlined here are valuable and help to explain the occasional poor outcome. We have become convinced that the use of a dorsal splint in the 1st week to 10 days following surgery is a helpful measure. It is designed to prevent the median nerve from prolapsing forward and becoming adherent to or trapped by the edges of the severed transverse carpal ligament. With regard to surgical management of carpal tunnel syndrome. It is exceedingly important to continue producing outcome studies showing that our interventions really do eliminate the problem and allow people to return to productive work. Templates for outcome assessment are under development by the Outcomes Committee of the American Association of Neurological Surgeons and the Congress of Neurological Surgeons and also by the American College of surgeons. Hopefully, they can be applied to the treatment of carpal tunnel syndrome. The following segment represents some suggested referral guidelines for patients with carpal tunnel syndrome. The present differential diagnosis, methods of confirming the diagnosis, and appropriate indications for considering surgery. These guidelines have been reviewed by the various authors who have contributed to this issue of Neurosurgical Focus and other colleagues in neurosurgery, orthopedics, plastic surgery, neurology, and occupational therapy. It is hoped that they will be a reasonable start in our efforts to inform referring physicians as to the nature of median thenar neuropathy and its overall management.

Journal Article↗
PubMed1997

Antiproliferative effect of the somatostatin analogue octreotide on growth hormone-producing pituitary tumors: results of a multicenter randomized trial.

OBJECTIVE: To determine and quantify the in vivo effects of octreotide on the cell cycle kinetics of growth hormone-producing pituitary adenomas. DESIGN: A multicenter randomized trial had been conducted to assess the clinical efficacy of octreotide, and we studied tissue specimens from pituitary macroadenomas in 32 patients with acromegaly from that trial-16 of whom had received 4 months of octreotide therapy before surgical resection and 16 of whom had undergone surgical resection only. MATERIAL AND METHODS: All tumors had been fully characterized on the basis of their immunophenotypic profile and their ultrastructural morphologic features. Included were 16 densely and 16 sparsely granulated somatotroph adenomas. In each case, immunostaining for the cell cycle-specific nuclear antigen Ki-67 was performed with use of the MIB-1 antibody. The staining reaction was manually quantified, and a tumor growth fraction was derived in each case. RESULTS: The mean growth fraction of tumors exposed to octreotide was suppressed by 83% in comparison with untreated surgical controls (0.011+/-0.004% versus 0.065+/-0.016%, respectively; P = 0.0068). The association between octreotide treatment and lower tumor growth fractions was statistically independent of tumor subtype, being evident among both sparsely and densely granulated somatotroph adenomas. CONCLUSION: Octreotide exerts a significant antineoplastic effect on somatotroph adenomas, one readily reflected at the level of the cell cycle. This antiproliferative response provides insight into several clinicopathologic issues surrounding octreotide therapy for these neoplasms.

Acromegaly↗
PubMed1997

Lumbar disc surgery in a fixed compensation population: a model for influence of secondary gain on surgical outcome.

BACKGROUND: Reported outcomes in patients undergoing surgical procedures for lumbar disc herniation are poorer in patients eligible for workers' compensation or with pending litigation. In the civilian community, the amount of compensation for one's disability is variable and thus its influence on surgical outcome is difficult to quantify. In the military, all members are covered by a standardized workers' compensation system, and have generally standardized work requirements, a standard pay scale, and third party evaluation of disability based on the Veterans Affairs rating system. This made the military a good system in which to study the effect of potential compensation on surgical outcome. METHODS: The study population consisted of active duty military members who underwent sequential lumbar microdiscectomies over a 31-month period. Omitted were lumbar fusions, decompressive laminectomies, and far lateral discectomies. Clinical and demographic variables, along with financial data for each patient were derived from these data. A good result was defined as return to active military duty. RESULTS: Three hundred forty-nine lumbar discectomies were performed in 348 active duty military members. Overall, 75.3% (262) of the 348 patients were able to return to full military duty after surgery, and 24.7% (86) received disability compensation. Chi-square univariate analysis showed higher compensation incentive was a significant determinant of poor surgical outcome (p = 0.0021). The influence of compensation incentive was proportional to the amount of anticipated payout, and relative to a military service member's usual income. In mutivariate analysis, lower base pay (0.0005) and female gender (p = 0.038) were predictive of poor outcome. CONCLUSIONS: Secondary gain in the form of disability pay has a proportionally adverse effect on outcome following lumbar disc surgery. Although studying this issue in the military system allowed standardization of secondary gain values, the influence of other factors could not be eliminated entirely. Potential disability pay is proportionally greater in lower ranked service members. Thus, other variables such as income level, education, and job satisfaction may contribute to the poorer results in this subgroup of military members.

Diskectomy↗
PubMed1997

Minimizing upper lip and incisor teeth paresthesias in approaches to transsphenoidal surgery.

Currently popular transsphenoidal approaches to the pituitary include sublabial, external rhinoplasty, alotomy, and transnasal techniques. The conventional sublabial approach remains the workhorse method despite postoperative lip edema, potential difficulty for denture wearers, and troublesome persistent upper lip and incisor teeth numbness. We traced the courses of the nasopalatine, infraorbital, and anterior superior alveolar nerves in 41 cadaveric half-head dissection to determine the exact contribution to upper lip and incisor teeth innervation. We then conducted a retrospective patient survey of 25 sublabial, 28 external rhinoplasty, 23 alotomy, and 12 transnasal approaches to the hypophysis to assess the incidence of upper lip and incisor teeth paresthesias lasting longer than 1 month. We conclude that rhinoplastic techniques are superior to the sublabial approach in limiting upper lip and incisor teeth numbness without compromising neurosurgical exposure for hypophysectomy.

Cadaver↗
PubMed1997

One century after the description of the "sign": Joseph Babinski and his contribution to neurosurgery.

One hundred years ago, in 1896, Joseph Babinski published a preliminary report on "réflexe cutané plantaire" (cutaneous plantar reflex), which became widely known as the Babinski sign. However, Babinski did not view the description of the sign as his major achievement. Instead, he considered his greatest contribution to medicine to be his having "... indiqué la voie à Martel et à Vincent" (pointed the way to Thierry de Martel and Clovis Vincent, founders of French neurosurgery). Several of Babinski's manuscripts deal with neurosurgical problems. In 1900, 1 year before Alfred Fröhlich's description, Babinski gave the first account of the adiposogenital syndrome and its relation to pituitary-hypothalamic disorder. Many other original contributions ensued. These include a report on the relief of papilledema by surgical decompression in 1901, the successful removal (in collaboration with de Martel) of an intracranial meningioma in 1909, the description (again with de Martel) of a cerebellopontine angle tumor treated by surgical excision with good result in 1925, and several manuscripts concerning diagnosis and treatment of compressive spinal cord lesions. Babinski's dream to establish a department of neurosurgery became a reality shortly after his death. The Hôpital de la Pitie in Paris, where Babinski did most of his work, established the first French department of neurosurgery chaired by Babinski's pupil, Vincent.

Eponyms↗
PubMed1997

Identification and localization of intracerebral vessels by microvascular doppler in stereotactic pallidotomy and thalamotomy: technical note.

OBJECTIVE: To identify intracerebral vessels in proximity to the target for thermocoagulation in functional neurosurgery, we use a microvascular doppler sensor held in a special supporting needle that fits in the straightening cannula for the thermocoagulation needle. TECHNIQUE: After insertion of the straightening cannula aimed at the stereotactic target, the microvascular doppler probe positioned at the tip of a supporting hollow needle is advanced through the cannula. The proximal micrometer gauge indicates the depth of the tip of the doppler probe. By setting the doppler device to the shortest focusing depth (0.1 mm), the maximum pulsatile vascular sound indicates the depth of the vessel. RESULTS AND CONCLUSION: A prominent vascular sound was identified in 3 of 13 cases. By adjusting the depth of the target, no major bleeding was experienced after thermocoagulation lesions were made. This technique secures and protects the fragile microvascular doppler and identifies any significant arterial vessels at the stereotactic target, thus avoiding vascular injury.

Cerebral Arteries↗
PubMed1997

Pitfalls and successes of peer review in neurosurgery.

As the first editor of the Journal of Neurosurgery, Louise Eisenhardt, acting with the advice of the editorial board, was responsible for making decisions on the acceptance or rejection of submitted manuscripts. Her log, covering the first 14 years of editorial decisions, is a record of neurosurgical progress and of the forces--scientific, technical and other--that shaped the field of neurosurgery. Any peer-review process is subject to pitfalls that become evident in retrospect, but an effective peer-review process is one of the basic ingredients of scientific progress. The decisions to accept or reject manuscripts submitted to the Journal of Neurosurgery during Eisenhardt's tenure are highlighted in this historical vignette.

Decision Making↗
PubMed1997

Overexpression of the growth-hormone-releasing hormone gene in acromegaly-associated pituitary tumors. An event associated with neoplastic progression and aggressive behavior.

The clinical behavior of growth hormone (GH)-producing pituitary tumors is known to vary greatly; however, the events underlying this variability remain poorly understood. Herein we demonstrate that tumor overexpression of the GH-releasing hormone (GHRH) gene is one prognostically informative event associated with the clinical aggressiveness of somatotroph pituitary tumors. Accumulation of GHRH mRNA transcripts was demonstrated in 91 of a consecutive series of 100 somatotroph tumors by in situ hybridization; these findings were corroborated by Northern analysis and reverse transcriptase polymerase chain reaction, and protein translation was confirmed by Western blotting. By comparison, transcript accumulation was absent or negligibly low in 30 normal pituitary glands. GHRH transcripts were found to preferentially accumulate among clinically aggressive tumors. Specifically, GHRH mRNA signal intensity was 1) linearly correlated with Ki-67 tumor growth fractions (r = 0.71; P < 0.001), 2) linearly correlated with preoperative serum GH levels (r = 0.56; p = 0.01), 3) higher among invasive tumors (P < 0.001), and 4) highest in those tumors in which post-operative remission was not achieved (P < 0.001). Using multivariate logistic regression, a model of postoperative remission likelihood was derived wherein remission was defined by the single criterion of suppressibility of GH levels to less than 2 ng/ml during an oral glucose tolerance test. In this outcome model, GHRH mRNA signal intensity proved to be the most important explanatory variable overall, eclipsing any and all conventional clinicopathological predictors as the single most significant predictor of postoperative remission; increases in GHRH mRNA signal were associated with marked declines in remission likelihood. The generalizability of this outcome model was further validated by the model's significant performance in predicting postoperative remission in a random sample of 30 somatotroph tumors treated at another institution. These data indicate that overexpression of GHRH gene is an event associated with the neoplastic progression and clinical aggressiveness of somatotroph adenomas. More generally, these data merge essential elements of the hypothalamic and pituitary hypotheses of pituitary tumorigenesis, providing for a more unified concept of neoplastic progression in the pituitary.

Acromegaly↗
PubMed1996

Epilepsy surgery in children and adolescents.

There has been a considerable increase in interest in the surgical management of intractable epilepsy in children. Better methods of diagnosis and improved knowledge of natural history and results of surgery have been major factors in this phenomenon. The results of surgery in 76 patients who were 19 years of age or younger are reported. Success rates, defined as no postoperative seizures with loss of consciousness (Engel Grades I and II) were 78% in 52 patients treated by temporal lobectomy, 75% in eight patients who had extratemporal resections, 80% in 10 children treated by hemispherectomy, and 33% in three patients treated by corpus callosotomy.

Journal Article↗
PubMed1996

Bromocriptine therapy for prolactin-secreting pituitary adenomas.

An effective systematic approach for the management of prolactin-secreting pituitary adenomas is described. This methodology has stood the test of time and has been modified in accordance with experience. The primary goals are to obtain satisfactory control of the tumor and to avoid undesirable side effects related to dopamine agonist-based therapeutic agents.

Journal Article↗