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Biomedical subjects

E T Hedley-Whyte

Publications and source records attributed to E T Hedley-Whyte.

At least 19 recordsLinked to original sources
PubMed1992

Childhood brain tumors that occupy more than one compartment at presentation. Multiple compartment tumors.

Children whose brain tumor involves two or more compartments at presentation differ clinically and pathologically from children whose brain tumor is confined to one compartment. In this study of 3,291 children with a brain tumor, at least 10% had a tumor that occupied two or three compartments at first hospitalization. Infratentorial tumors occupying multiple compartments were 1.7 times more likely to involve the cervicomedullary junction than the mesodiencephalic junction. Younger children (1-3 years) were more likely to have had multiple compartment tumors than older children. Children whose tumor was limited to the infratentorial compartment had a longer survival than children whose tumor also occupied other compartments. Ependymoma, anaplastic ependymoma, and astrocytoma (nos) were over represented among infratentorial multiple compartment tumors. Pilocytic astrocytoma, primitive neuroectodermal tumor (medulloblastoma), and desmoplastic medulloblastoma were less likely to have occupied multiple compartments at the time of the first surgical exploration. The distributions of histologic features in tumors at the cervicomedullary junction differed from those in tumors limited to the posterior fossa or to the spinal canal. Seizures were more likely if the tumor was confined to the supratentorial compartment, whereas nausea or vomiting and headache were more likely if the tumor was confined to the infratentorial compartment. Children whose tumor was confined to the spinal canal were significantly more likely to have bladder symptoms and back and/or abdominal pain than those whose tumor also involved compartments above the foramen magnum. We conclude that brain tumors apparently confined to one compartment at presentation are biologically and structurally different from tumors evident in two or more compartments.

Adolescent↗
PubMed1992

Epidemiology of seizures in children with brain tumors. The Childhood Brain Tumor Consortium.

We examined potential clinical and pathologic correlates of seizures among the 3,291 children in the Childhood Brain Tumor Consortium database. Fourteen percent had seizures prior to their hospitalization for a brain tumor. Among children who had a supratentorial tumor, seizures occurred in 22% of those less than 14 years of age. The prevalence of seizures increased to 68% of older teenagers. Among children with an infratentorial tumor, the prevalence of seizures was relatively constant at 6% over all age groups. The onset of seizures began more than one year prior to surgical tumor removal in over half of the children aged five or more with supratentorial tumors, significantly longer than for those of the same age with infratentorial tumors. Almost all children (98.9%) with an infratentorial tumor and seizures had at least one other symptom and more than three-fourths of them had at least three. Eighty-nine percent of children with a supratentorial tumor and seizures had at least one other symptom and more than one-half had at least three symptoms. Regardless of whether the tumor was above or below the tentorium, confusion or stupor and coma were more common in children with seizures than in children without seizures. Among children with supratentorial tumors, symptoms of a declining academic performance or an abnormality of personality, speech, walking, or sensation were significantly more frequent in children with seizures, while visual symptoms (other than visual loss or diplopia) and nausea or vomiting were less frequent. Among children with supratentorial tumors, those who had seizures were more likely to have paralysis of an arm, hand, or face, confusion or stupor, or coma and less likely to exhibit irritability, papilledema, optic atrophy, decreased visual acuity, pupillary abnormalities, or abducens paresis. Among children with infratentorial tumors, those with seizures were significantly less likely to have truncal ataxia, but more likely to experience confusion, stupor, or coma. In the supratentorial compartment, astrocytoma (nos), protoplasmic astrocytoma, anaplastic astrocytoma, and ependymoma were more frequently associated with seizures than was craniopharyngioma. No infratentorial tumor type was more or less likely to be associated with seizures. All common tumor types that were represented in both the supratentorial and the infratentorial compartment except astrocytoma (nos) were associated with significantly greater rates of seizures when located in the supratentorial compartment. The tumor location with the highest incidence of seizures was, as expected, the superficial cerebrum. More than 40% of the children with such tumors had seizures.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1992

Temporal trends among childhood brain tumor biopsies. The Childhood Brain Tumor Consortium.

We sought temporal trends in the demographic, clinical, histologic feature, diagnostic class, and quality of life data over the interval 1930-1979 in the Childhood Brain Tumor Consortium database. The proportion of children younger than eight years old declined from 72% to 55% and the proportion of those older than ten more than doubled from 12% to 27%. The relative frequency of tumors in the supratentorial compartment increased significantly, while infratentorial tumors decreased. We found significant declines in supratentorial ependymomas and pilocytic astrocytomas. Similarly, some infratentorial tumors, especially ependymomas, decreased and brain stem tumors increased. Infratentorial medulloblastoma (primitive neuroectodermal tumor) increased significantly. Some individual histologic features which are markers of anaplasia increased in frequency in both supratentorial and infratentorial tumors. There was a significant increase in biopsies that contained nonneoplastic neural tissue in addition to tumor for both compartments and among supratentorial tumors there was a marked increase in the proportion of cases containing an indistinct neural tissue boundary. The probability of postoperative death declined, but the probability of survival five or ten years after surgery did not improve significantly for children who had tumors in either compartment. Among children who survived five years after the initial craniotomy, the proportion who had significant long term deficits increased. Most of this increase occurred in the last decade (1970-79). In this decade, the proportion of children for whom no deficits were reported five years following operation was 4% if they had a supratentorial tumor and 27% if they had an infratentorial tumor. The proportions of children alive five years following first surgery who had arachnoidal metastases increased significantly for infratentorial tumors.

Adolescent↗
PubMed1992

Use of the silver nucleolar organizer region (AgNOR) technique in the differential diagnosis of central nervous system neoplasia.

Because the distinction between gliosis and low-grade astrocytoma may prove difficult by routine light microscopy, we evaluated the silver nucleolar organizer region (AgNOR) technique in making this distinction. The AgNOR impregnation was performed on formalin-fixed, paraffin-embedded tissue from 49 central nervous system (CNS) biopsies: eight normal brain, 14 gliosis, 14 grade 2 astrocytoma (Daumas-Duport scale), two grade 4 astrocytoma, nine medulloblastoma, one metastatic carcinoma, and one choroid plexus papilloma. Quantitative and qualitative differences were found between gliosis and low-grade astrocytomas. In gliosis, AgNOR counts averaged 1.18 +/- 0.11 (SD) AgNOR/nucleus, while in low-grade astrocytomas AgNOR counts averaged 2.22 +/- 0.39 (p less than 0.001). Compound AgNOR were frequent in 9/14 grade 2 astrocytomas and in both grade 4 astrocytomas, whereas compound AgNOR were extremely rare in cases of gliosis. Quantitative and qualitative differences were also found between normal cerebellar internal granular cells and medulloblastoma cells. Cerebellar granular cells averaged 0.90 +/- 0.10 AgNOR/nucleus whereas medulloblastoma cells had an average of 4.52 +/- 0.95 (p less than 0.001). Compound AgNOR were seen in all medulloblastomas but not in internal granular cells. These findings suggest that the AgNOR technique may be a useful adjunct in the diagnosis of CNS neoplasia.

Astrocytoma↗
PubMed1992

Ras mutations in human pituitary tumors.

The cellular basis for pituitary neoplasia is poorly understood. Mutations that activate the ras protooncogenes have been identified in a number of different types of human cancers and potentially represent one of the genetic alterations that occur in pituitary tumors. In this study we examined 19 pituitary tumors for the occurrence of ras mutations. The tumor types included 11 nonfunctioning adenomas, 6 somatotroph adenomas, and 2 prolactinomas. Each of the three ras genes (K-ras, N-ras, and H-ras) was amplified from pituitary tumor DNA using the polymerase chain reaction. Oligonucleotide-specific hybridization was used to screen for mutations that inhibit GTPase activity and cause activation of the ras oncogene. No ras mutations were observed in 18 of the pituitary adenomas. However, a mutation was identified in codon 12 of the H-ras gene (Gly to Val) in a recurrent prolactinoma that was highly invasive and ultimately proved to be fatal. We conclude that ras mutations are uncommon in pituitary adenomas, but may provide a marker for highly invasive tumors.

Adenoma↗
PubMed1992

Glycoprotein hormone alpha-subunit production in somatotroph adenomas with and without Gs alpha mutations.

Activating mutations of the Gs alpha subunit have been identified in a subset of somatotroph adenomas. The mutant form of the Gs alpha subunit causes persistent activation of adenylyl cyclase and consequently results in high intracellular levels of cAMP. Because cAMP is known to stimulate the synthesis of the glycoprotein hormone (GPH) alpha-subunit as well as GH, we examined somatotroph tumors with and without Gs alpha mutations for GPH alpha-subunit production. GPH alpha-subunit production was assessed in vivo by measuring serum hormone levels and in vitro by analyzing hormone secretion by cultured pituitary tumor cells. DNA was extracted from the pituitary tumors of 26 acromegalic patients. The Gs alpha gene was amplified by the polymerase chain reaction and screened for mutations at codons 201 and 227 using oligonucleotide specific hybridization. Nine of the 26 tumors (35%) had point mutations at Arg 201. Seven of these tumors contained a CGT to TGT mutation (Arg to Cys) and 2 contained a CGT to CAT mutation (Arg to His). No mutations were detected at codon 227. There were no significant differences in age, sex distribution, tumor size, or serum levels of GH or insulin-like growth factor-1 between the groups of patients with or was Gs alpha mutations. The mean serum level of the free GPH alpha-subunit was 1.9-fold higher in the group with Gs alpha mutations (0.48 +/- 0.37 micrograms/L) than in patients without mutations (0.25 +/- 0.17) (P less than 0.05). In pituitary tumor cell culture, 75% of somatotroph tumors with Gs alpha mutations secreted free GPH alpha-subunit into the media compared with 45% of tumors without Gs alpha mutations. The amount of GPH alpha-subunit secretion was 12-fold greater in the group of tumors containing the Gs alpha mutation (P less than 0.05). Immunocytochemical detection of the free GPH alpha-subunit was similar in the two groups of patients with 75% positive for the GPH alpha-subunit in tumors with Gs alpha mutations and 67% positive in tumors without mutations (P = 0.69). We conclude that GPH alpha-subunit production occurs in somatotroph tumors with and without Gs alpha mutations. The increased levels of GPH alpha-subunit secretion in vivo and in vitro suggest that the Gs alpha mutation may increase the amount of preexisting GPH alpha-subunit biosynthesis in the tumors, perhaps via activation of the cAMP pathway.

Adenoma↗
PubMed1992

Clonal origins of adrenocorticotropin-secreting pituitary tissue in Cushing's disease.

It is unclear whether Cushing's disease results from a primary pituitary disorder or arises in response to abnormal hypothalamic control of the pituitary gland. Clonal analysis can provide information as to whether neoplastic tissue is derived from a monoclonal proliferation of a genetically altered cell or from a polyclonal expansion of a group of cells affected by a common stimulus. We used X-linked restriction fragment length polymorphisms at the phosphoglycerate kinase, hypoxanthine phosphoribosyltransferase, and DXS255 loci in 11 women with biochemically and pathologically confirmed Cushing's disease to determine the clonal origins of corticotroph adenomas and corticotroph hyperplasia. Tumor tissue from all 10 women with morphologically and immunohistochemically confirmed ACTH-secreting pituitary microadenomas demonstrated a monoclonal pattern. Pathologically confirmed corticotroph hyperplasia in a patient with a CRH-secreting bronchial carcinoid was found to be polyclonal. We conclude that corticotroph microadenomas in Cushing's disease are monoclonal, supporting the theory that a spontaneous somatic mutation is the primary pathogenetic mechanism in this disorder. In addition, the demonstration of polyclonality in corticotroph hyperplasia implies that excess of hypothalamic hormones is an etiologic mechanism in cases of Cushing's syndrome associated with ectopic CRH-secreting tumors.

Adrenocorticotropic Hormone↗
PubMed1992

Olfactory dysgenesis or hypoplasia: a variant in the arhinencephaly spectrum?

Postmortem examination of a 65-year-old anosmic woman revealed rudimentary olfactory bulbs, an imperforate cribriform plate, and sulcal abnormalities of the orbitofrontal surface of the brain. The remainder of the brain, skull, and body was normal. This abnormality most likely resulted from a local insult to the area of the cribriform plate during early fetal life, occurring after the induction of olfactory bulb differentiation, but before migration and complete differentiation of the olfactory bulbs. Such a lesion can be dated to approximately 11 to 12 weeks gestational age. The malformation may represent another variant in the arhinencephaly spectrum, but is termed "olfactory dysgenesis" or "olfactory hypoplasia" to separate it from true olfactory aplasia and arhinencephaly.

Aged↗
PubMed1992

Neurofibrillary tangles but not senile plaques parallel duration and severity of Alzheimer's disease.

We studied the accumulation of neurofibrillary tangles (NFTs) and senile plaques (SPs) in 10 Alzheimer's disease patients who had been examined during life. We counted NFTs and SPs in 13 cytoarchitectural regions representing limbic, primary sensory, and association cortices, and in subcortical neurotransmitter-specific areas. The degree of neuropathologic change was compared with the severity of dementia, as assessed by the Blessed Dementia Scale and duration of illness. We found that (1) the severity of dementia was positively related to the number of NFTs in neocortex, but not to the degree of SP deposition; (2) NFTs accumulate in a consistent pattern reflecting hierarchic vulnerability of individual cytoarchitectural fields; (3) NFTs appeared in the entorhinal cortex, CA1/subiculum field of the hippocampal formation, and the amygdala early in the disease process; and (4) the degree of SP deposition was also related to a hierarchic vulnerability of certain brain areas to accumulate SPs, but the pattern of SP distribution was different from that of NFT.

Aged↗
PubMed1991

Expression of angiogenic growth factor genes in primary human astrocytomas may contribute to their growth and progression.

Astrocytomas are highly malignant brain tumors and are among the most neovascularized solid tumors. We have investigated the expression of the angiogenic growth factors acidic fibroblast growth factor and transforming growth factor-alpha, together with its receptor epidermal growth factor receptor, in 30 primary astrocytomas. Both acidic fibroblast growth factor and transforming growth factor-alpha, together with epidermal growth factor receptor, are found to be greatly overexpressed in these tumors when compared with normal brain. This overexpression of angiogenic growth factors may underlie the intense neovascularization characteristic of astrocytomas.

Angiogenesis Inducing Agents↗
PubMed1991

Cerebral amyloid angiopathy without and with cerebral hemorrhages: a comparative histological study.

To identify those factors associated with cerebral hemorrhage among brains with cerebral amyloid angiopathy (CAA), we undertook a comparative postmortem histopathological study of amyloid-containing vessels in the brains of patients with and without hemorrhage. Those without hemorrhage were represented by the following two groups: (1) elderly patients from a large general hospital (n = 66; age range, 75-107 years) and (2) patients with various neuropsychiatric disorders (n = 70; age range, 27-96 years). CAA was found in 45% of the first group and in 54% of the second group. The findings in these patients were compared with those in 17 brains in which both CAA and cerebral hemorrhage were present. We found that CAA was more severe in the brains with cerebral hemorrhage than in those without, and that fibrinoid necrosis was seen only in the brains with cerebral hemorrhage (12 of the 17 brains). Microaneurysms occurred only in the presence of severe, rather than moderate or mild, CAA. Serial sections in 2 brains of patients with cerebral hemorrhage showed fibrinoid necrosis, microaneurysms, and vascular rupture in close association with the hemorrhage. In 2 patients, hemorrhage was precipitated by trauma, and in 1, it was secondary to metastatic carcinoma. The features of brains from patients with CAA that are most consistently related to cerebral hemorrhage are (1) a severe degree of CAA and (2) the presence of fibrinoid necrosis, with or without microaneurysms.

Adult↗
PubMed1991

TP53 gene mutations and 17p deletions in human astrocytomas.

Astrocytomas, including the most malignant form, glioblastoma multiforme, are the most frequent and deadly primary tumors of the human nervous system. Recent molecular genetic analyses of astrocytomas have demonstrated frequent chromosome 17 deletions involving the telomeric region of the short arm (17p12-pter). This region contains a candidate tumor suppressor gene, TP53, which has recently been implicated in the etiology of a broad array of human cancers. To study the possible role of TP53 in astrocytoma development, 24 randomly chosen human astrocytic tumors were examined for genomic TP53 sequence aberrations using primer-directed DNA amplification in conjunction with direct sequencing. Five of the 11 grade III astrocytomas (glioblastoma multiforme), but only one of seven grade II astrocytomas (anaplastic astrocytoma) and none of either the grade I astrocytomas or oligodendrogliomas demonstrated distinct point mutations involving the TP53 gene. These data suggest that TP53 mutations may play a role in astrocytoma development and are predominantly associated with higher grade tumors.

Adult↗
PubMed1991

Proliferating cell nuclear antigen and Ki-67 immunohistochemistry in brain tumors: a comparative study.

Proliferating cell nuclear antigen (PCNA) is a 36-kDa DNA polymerase-delta auxiliary protein which accumulates in the nucleus during S phase of the cell cycle. Immunohistochemical labeling indices (LI) of PCNA and Ki-67 were compared using an avidin-biotin complex method on frozen sections of 27 nervous system tumors. 3 normal cerebral cortices, and 3 peripheral nerves. In glial tumors, PCNA and Ki-67 LI increased with increasing tumor grade (Daumas-Duport system). In 5 low-grade glial tumors, PCNA and Ki-67 LI were less than or equal to 1%, except for one optic nerve glioma (Ki-67 LI = 6%). In 7 grade 3 astrocytomas and 1 mixed glioma, PCNA LI were less than or equal to 1-1.5%, while Ki-67 LI were 2%-10%. In 7 grade 4 astrocytomas and 1 metastatic carcinoma, PCNA LI ranged from 6%-15% while Ki-67 LI ranged from 17%-30%. In 5 of 6 schwannomas, focally high PCNA LI (4%-65%) were noted, despite low LI with Ki-67 (less than or equal to 1.6%). Scattered normal schwann cell nuclei also stained with PCNA, but normal cerebral cortex did not.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain Neoplasms↗
PubMed1991

Correlates of survival and the Daumas-Duport grading system for astrocytomas.

In order to examine the correlation between prognosis and the histological features of nuclear atypia, mitosis, endothelial proliferation, and necrosis in supratentorial adult astrocytomas, the authors reviewed 251 such cases treated at the Massachusetts General Hospital between 1972 and 1980. One point was given for the presence of each feature. The total number of features was translated into a grade as follows: none of the four features = Grade 1 (one patient), one feature = Grade 2 (36 patients), two features = Grade 3 (33 patients), and three or four features = Grade 4 (181 patients). The period of survival was significantly associated with grade, the presence or absence of each of the four histological features, patient's age, type of operation, radiation therapy, and extent of tumor (log rank, p less than 0.05). The variables associated with grade were age (p less than 0.001) and radiation therapy (p less than 0.02). After adjustment for these variables using a Cox proportional-hazards model, the difference in overall survival time between patients in Grades 2 and 3 was not statistically significant. When comparable groups of patients were examined in terms of age or receipt of radiation therapy, the median survival times differed markedly. Patients 50 years of age or less had a median survival time of 68 months (Grade 2 tumors), 29 months (Grade 3 tumors), and 13 months (Grade 4 tumors). Patients over 50 years of age had a median survival time of 6 months (Grade 2 and 4 tumors) and 9 months (Grade 3 tumors). Those patients who had received radiation therapy had a median survival time of 68 months (Grade 2 tumors), 21 months (Grade 3 tumors), and 11 months (Grade 4 tumors). Those patients who did not receive radiation therapy had a median survival time of 1 month (Grade 2 tumors) and 2 months (Grade 3 and 4 tumors); over half of these patients died within 2 months of surgery. This grading system, originally proposed by Daumas-Duport, et al., is simple, objective, and reproducible, and correlates well with survival times. The authors recommend that astrocytomas be graded on a scale of 1 to 4, with Grade 1 reserved for the rare adult supratentorial astrocytoma with none of the four histological features.

Adolescent↗
PubMed1991

Coexpression of galanin and adrenocorticotropic hormone in human pituitary and pituitary adenomas.

Galanin is a neuropeptide that regulates the secretion of several pituitary hormones, including prolactin (PRL) and growth hormone (GH). Galaninlike immunoreactivity (Gal-IR) and galanin mRNA in the rat anterior pituitary is cell lineage specific, with predominant expression in lactotrophs and somatotrophs. The authors examined the cellular distribution of human Gal-IR in seven normal postmortem pituitaries and 62 pituitary tumors by immunoperoxidase staining. In contrast to the rat, Gal-IR in human anterior pituitaries was present in corticotrophs scattered throughout the gland, but not in lactotrophs, somatotrophs, thyrotrophs, or gonadotrophs. Distinct Gal-IR also was present in hyperplastic and neoplastic corticotrophs in 19 of 22 patients with Cushing's disease. In noncorticotroph cell tumors, unequivocal Gal-IR was present in 5 of 11 GH-secreting tumors associated with clinical acromegaly, 9 of 18 nonfunctioning pituitary adenomas, and 2 of 14 prolactinomas. Of these galanin-positive tumors, four of the five GH-secreting adenomas, six of the nine nonfunctioning adenomas, and both of the prolactinomas also contained adrenocorticotropic hormone immunoreactivity (ACTH-IR). Immunostaining and in situ hybridization on adjacent sections using an 35S-labeled probe complementary to human galanin mRNA demonstrated predominant galanin expression in normal corticotrophs. Immunoelectron microscopy confirmed the presence of Gal-IR in pituitary cells characteristic of corticotrophs in both normal and neoplastic pituitaries. Thus, as in the rat, galanin gene expression in the human pituitary is cell-type specific. Unlike the rat, however, human galanin gene expression is restricted to the corticotroph lineage. Studies of tumors confirmed the observed coexpression of galanin and adrenocorticotropic hormone. The divergent cell type specificity of galanin production in human and rat pituitaries reflects different patterns of gene activation in these two species. In addition, these results suggest that galanin in the human pituitary may participate locally in the regulation of the hypothalamic-pituitary-adrenal axis.

Adenoma↗
PubMed1990

Human meningiomas co-express platelet-derived growth factor (PDGF) and PDGF-receptor genes and their protein products.

The present studies investigated the expression of the platelet-derived growth factor (PDGF) and PDGF-receptor genes in human meningiomas. Northern blot analysis demonstrated that all meningiomas examined expressed both the c-sis/PDGF-2 proto-oncogene and the PDGF-receptor gene. In situ hybridization localized the c-sis mRNA and the PDGF-receptor mRNA in the tumor cells of the meningioma tissues. Control pachymeninges derived from adult individuals, without meningiomas, expressed only PDGF-receptor mRNA but not the c-sis mRNA. Immunocytochemistry studies detected both the c-sis and the PDGF-receptor protein products in meningioma tissues but only the PDGF-receptor protein products in control pachymeninges. These findings indicate the presence of an autocrine mechanism in human meningiomas based on the co-expression of the c-sis/PDGF-2 proto-oncogene and PDGF-receptor gene and their protein products. This co-expression of a potent mitogen and its receptor may contribute to the growth and maintenance of human meningiomas.

Blotting, Northern↗
PubMed1990

Childhood brain tumor: presentation at younger age is associated with a family tumor history.

In a registry-based sample of 361 children with a brain tumor, those whose grandparents and great-grandparents had a history of any kind of tumor were younger at the time of presentation than were those who lacked this family history (p = 0.1). In post hoc analyses, the age difference was most apparent among children with cerebral tumors, and when family history was limited to brain tumors and to great-grandparents. These findings are in keeping with the hypothesis that a familial tumor diathesis contributes to an early age at onset of a brain tumor in some children.

Age Factors↗