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R T Cunningham

Publications and source records attributed to R T Cunningham.

At least 19 recordsLinked to original sources
PubMed2001

Analysis of the post-translational processing of chromogranin A in rat neuroendocrine tissue employing an N-terminal site-specific antiserum.

Chromogranin A (CgA) is a complex prohormone expressed as a constituent of the regulated secretory pathway of numerous neuroendocrine cells. Recent investigations have demonstrated that CgA is selectively cleaved to generate distinct peptides in different neuroendocrine tissues. This investigation employed a site-specific antiserum that detects residues 98-106 rat CgA to examine the amino-terminal processing of CgA to generate beta-granin and related peptides in rat neuroendocrine tissues. Immunohistochemistry revealed moderate to intense beta-granin-like immunostaining in cells scattered throughout the anterior pituitary, thyroid, in the islets of Langerhans and in the mucosa of the gastrointestinal tract. Variable intensities of immunostaining were observed in distinct clusters of chromaffin cells. Quantitatively, the highest concentration of beta-granin-like immunoreactivity was detected in pituitary extracts. Significantly lower concentrations were detected in adrenal and thyroid glands, brain, ventral and dorsal pancreatic lobes and gastrointestinal tissue extracts. Chromatography resolved three distinct beta-granin-like immunoreactants; a large CgA-like form, an intermediate molecular form presumably corresponding to beta-granin (rat CgA1-128) and small immunoreactants that coeluted with the synthetic peptide. Two beta-granin-like immunoreactants, 21 and 22 kDa, were detected following immunoblot analysis of pituitary extracts. This study has demonstrated that chromogranin A is subject to distinct amino-terminal patterns of tissue-and cell-specific processing to generate a beta-granin-like immunoreactant which is additionally cleaved in pancreatic, fundic and colonic tissue to generate previously unidentified peptides.

Amino Acid Sequence↗
PubMed2001

Cell-specific processing of chromogranin A in endocrine cells of the rat stomach.

The rat stomach is rich in endocrine cells. The acid-producing (oxyntic) mucosa contains ECL cells, A-like cells, and somatostatin (D) cells, and the antrum harbours gastrin (G) cells, enterochromaffin (EC) cells and D cells. Although chromogranin A (CgA) occurs in all these cells, its processing appears to differ from one cell type to another. Eleven antisera generated to different regions of rat CgA, two antisera generated to a human (h) CgA sequences, and one to a bovine (b) CgA sequence, respectively, were employed together with antisera directed towards cell-specific markers such as gastrin (G cells), serotonin (EC cells), histidine decarboxylase (ECL cells) and somatostatin (D cells) to characterize the expression of CgA and CgA-derived peptides in the various endocrine cell populations of the rat stomach. In the oxyntic mucosa, antisera raised against CgA(291-319) and CGA(316-321) immunostained D cells exclusively, whereas antisera raised against bCgA(82-91) and CgA(121-128) immunostained A-like cells and D cells. Antisera raised against CgA(318-349) and CgA(437-448) immunostained ECL cells and A-like cells, but not D cells. In the antrum, antisera against CgA(291-319) immunostained D cells, and antisera against CgA(351-356) immunostained G cells. Our observations suggest that each individual endocrine cell type in the rat stomach generates a unique mixture of CgA-derived peptides, probably reflecting cell-specific differences in the post-translational processing of CgA and its peptide products. A panel of antisera that recognize specific domains of CgA may help to identify individual endocrine cell populations.

Animals↗
PubMed1999

Immunostaining for vasostatin I distinguishes between ileal and lung carcinoids.

Although chromogranin A (CgA) is a recognized marker of neuroendocrine tumours, little is known about the distribution of the CgA-derived peptides, vasostatin (VST) I or II, in these tumours. Rabbit polyclonal antiserum was raised to a fragment of VST I and used to immunostain sections (5 microns) of wax-embedded tumour tissue. Immunoreactivity (IR) was detected using swine anti-rabbit fluorescein secondary antibody and sections were viewed by fluorescence microscopy. Of 24 tumours from patients with lung carcinoids, one was weakly positive, while 23 of 26 ileal carcinoid tumours were immunoreactive. Metastatic deposits from patients with ileal carcinoids also tended to be immunoreactive (9/10). The difference in IR between lung and ileal carcinoid primary tumours did not appear to be related to the metastatic potential, since appendiceal tumours, which seldom metastasize, also tended to be immunoreactive (4/6) for VST I. The strongest IR was recorded in two patients with flushing as a result of ileal carcinoids; five other 'flushers' with ileal carcinoids were also immunopositive for VST I-like IR. By contrast, patients with flushing as a result of lung carcinoids were immunonegative for VST. In conclusion, VST I-like IR may assist in the identification of a secondary deposit from an unknown primary site.

Biomarkers, Tumor↗
PubMed1999

Neurone-specific enolase and N-acetyl-aspartate as potential peripheral markers of ischaemic stroke.

BACKGROUND: After stroke, brain-specific proteins (including neurone-specific enolase) leak into the blood. The question addressed in the present study was whether N-acetyl-aspartate (amino acid derivative localized in cerebral neurones) could also serve as a peripheral marker of ischaemic damage. N-acetyl-aspartate levels were determined in the blood of stroke patients and related to clinical outcome, volume of infarction and to serum neurone-specific enolase. METHODS: Blood samples from 19 patients (seven women, 12 men, mean age of 73 years, range 56-88 years) were collected during the first 4 days after stroke and analysed for neurone-specific enolase (radioimmunoassay) and/or N-acetyl-aspartate (mass spectrometry). Clinical outcome was assessed using the Glasgow Outcome Score, and volume of infarction was calculated using computerized tomography (CT). Control values of N-acetyl-aspartate, determined in six female and nine male volunteers (mean age 47.4 years; range 28-73 years) were 0.26 +/- 0.02 mumol L-1. RESULTS: The increase in serum N-acetyl-aspartate was highly significant (P < 0.0001) within the first 24 h and at 72 h after stroke and correlated (P < 0.05) with volume of infarction only in patients with a bad prognosis (Glasgow Outcome Score < 5). Serum N-acetyl-aspartate at 24 h and neurone-specific enolase at 72 h were negatively correlated, suggesting that more N-acetyl-aspartate reaches the blood when brain tissue is less irreversibly affected. CONCLUSION: Serum N-acetyl-aspartate appears to be an early peripheral marker of ischaemically affected brain neurones, and the ratio of N-acetyl-aspartate to a protein marker, such as NSE, may serve as an index of irreversibility.

Aged↗
PubMed1998

TFF1 gene expression in human medullary thyroid carcinoma.

Medullary thyroid carcinoma (MTC) is an uncommon tumour of calcitonin-secreting C-cells of the thyroid gland. This cancer represents an important potential model for the study of mechanisms of human epithelial cell transformation. Although recent studies have identified the gene involved in familial forms of MTC, little is known about the molecular pathogenesis of the sporadic variants of this tumour. The biological and prognostic significance of TFF1 expression, particularly in diverse human malignancies, suggests that the TFF1 protein could have a role in human neoplasia. Furthermore, in prostate cancer it has been demonstrated that TFF1 expression is closely associated with premalignant changes and neuroendocrine differentiation. In the present study, the expression of TFF1 was analysed in 18 human MTCs, comprising sporadic and familial tumours, C-cell hyperplasia, and one case of lymph gland metastasis. TFF1 expression was also examined in the cultures of a human MTC-derived tumour cell line (TT cell line). The results showed that ten sporadic tumours, three hereditary tumours (including C-cell hyperplasia), and one lymph gland metastasis displayed TFF1 immunoreactivity. Indirect fluorescence immunocytochemistry and Western blotting revealed that the TFF1 protein was strongly expressed in the TT cells. Northern analysis revealed that tumours and TT cells expressed the TFF1 transcript. Although the function of TFF1 protein in the carcinogenesis of MTC remains to be elucidated, its expression in the majority of cases of both sporadic and hereditary tumours, metastatic tumours, and in C-cell hyperplasia suggests that it may contribute to the pathogenesis of MTC.

Adolescent↗
PubMed1997

Regulatory peptides and other neuroendocrine markers in medullary carcinoma of the thyroid.

Medullary thyroid carcinoma (MTC) is an APUDoma (APUD refers to amine precursor uptake and decarboxylation) arising from the parafollicular cells. Diarrhoea has been reported in some 30% of patients, variously attributed to excess production of calcitonin (CT), serotonin (5-HT), vasoactive intestinal peptide (VIP) or other factors. The regulatory factors in MTC were examined employing immunocytochemistry and RIA to tumours and their extracts. The patients were followed up for more than 15 years. CT and calcitonin gene-related peptide were universally expressed in all the tumours. The neuroendocrine markers chromogranin A (and its fragments pancreastatin and WE-14), neurone-specific enolase, protein gene product 9.5 and carcino-embryonic antigen were found in the majority of MTCs and might be useful as immunocytochemical markers. 5-HT, substance P, neurokinin A, glucagon and VIP could not be detected, excluding them as candidates in the diarrhoea of MTC.

Apudoma↗
PubMed1996

PC12 cells show immunoreactivity to a number of proteins and peptides, including vasostatin.

N-terminal chromogranin A (CGA) contains peptides with vasoinhibitory properties, called vasostatin I (VST) and II [CGA (1-76) and (1-113) in human and bovine; (1-128) in rat]. Three fragments of VST were synthesized and antisera raised: human CGA (68-76) (VST I) rat CGA (121-128) (VST II fragment 2), and bovine/human CGA (83-91) (VST II, fragment 3). Strong immunoreactivity was observed in PC12 cells with antisera to VST II, fragment 3, VST I, and neuron-specific enolase. Little or no immunoreactivity was observed using antisera to synaptophysin, whole molecule CGA, pancreastatin, protein gene product 9.5, somatostatin, pancreatic polypeptide, or with antibodies 875 and 876 to VST II, fragment 2. Most of the VST antisera cross-reacted, with a species of molecular weight, 61 kDa but one, 874, cross-reacted with two species of molecular weights, 7.2 and 12 kDa. Our results show the presence of N-terminally processed CGA in PC12 cells.

Amino Acid Sequence↗
PubMed1996

Serum neurone-specific enolase as an indicator of stroke volume.

Serum neurone-specific enolase (NSE) and computerized tomography (CT) stroke volume were compared in patients admitted within 24 h of an acute stroke. Serum samples were obtained on admission and daily for the next 4 days. Of 163 patients, CT scans revealed 25 with intracerebral haemorrhages, one haemorrhagic infarct and 83 measurable acute infarcts. The serum NSE levels of those with infarcts was significantly higher than in those with haemorrhages at 48 (P = 0.0003) and 72 h (P = 0.04). The maximum serum NSE value tended to occur later in those with large infarcts (P = 0.0035). There was a significant correlation between infarct volume and serum NSE at 48 h (r = 0.27, P = 0.015) and 96 h (r = 0.27, P = 0.015) and with the maximum serum NSE over the 4 days (r = 0.36, P = 0.001). There was no significant correlation between haemorrhage volume and NSE. In conclusion, serum NSE may be a useful marker of infarct volume in studies of therapy in acute stroke. Sampling for NSE should continue, at least in those with large infarcts, for longer than 4 days. Serum NSE cannot be used to distinguish between haemorrhage and infarction in patients with an acute stroke.

Adult↗
PubMed1996

Neuron-specific enolase as an aid to outcome prediction in head injury.

A statistically significant elevation was observed in serum and CSF neuron-specific enolase (NSE) levels in patients with major head injury, relative to control individuals. No correlation was noted between serum NSE and either APACHE II, Injury Severity Score (ISS), Glasgow Outcome Score (GOS) or Glasgow Coma Scale (GCS). A significant correlation was noted between CSF NSE levels and GCS, but not between CSF NSE and APACHE II, ISS or GOS. Of the patients with major head injury, 100% had NSE CSF levels above the normal level, while 47% had elevated serum NSE levels. In nine patients with major head injury, changes in CSF levels reflected changes in serum NSE levels. In all nine patients, serum NSE decreased to reach normal values, regardless of the outcome as predicted by the GOS. Therefore, while NSE would appear to be a marker of neuronal cell damage, other markers are also essential.

Adult↗
PubMed1994

Serum neurone-specific enolase concentrations in patients with neurological disorders.

A radioimmunoassay (RIA) has been developed for neurone-specific enolase (NSE) and used to measure serum levels in patients with a range of neurological disorders. Serum NSE levels were within the normal range in 21 patients with multiple sclerosis and 4 patients with Guillain-Barre syndrome. Normal serum NSE levels were also recorded in patients with motor neurone disease, anterior spinal thrombosis, multi-infarct disease, benign intracranial hypertension and peripheral neuropathy. However, two patients in coma, one as a result of encephalitis, the other due to subarachnoid haemorrhage (SAH) had elevated serum NSE. In the former, serum NSE levels appeared to predict a deterioration in clinical state, levels later returning to normal before an improvement in clinical condition. In the patient with SAH, levels were elevated on admission and remained elevated until death. Serum NSE levels may be of use in predicting outcome in patients with acute neurological disease.

Adolescent↗
PubMed1994

Controlled-release panel traps for the Mediterranean fruit fly (Diptera: Tephritidae).

Solid, controlled-release dispensers containing 2 g of the synthetic attractant trimedlure now are used in Jackson traps to detect the Mediterranean fruit fly, Ceratitis capitata (Wiedemann). Panel traps consisting of trimedlure mixed in a sticky substance and spread on the surfaces of a plastic panel are used to delineate the limits of discovered insect infestations in California. We describe the development of controlled-release, polymeric panels that prolong release of trimedlure and a highly attractive analog, ceralure. Attractants were incorporated in a polyethylene matrix to form panels and in a polymer coating on cardboard panels that then were evaluated by biological and chemical assay. In addition, commercial polymer matrix panels were evaluated. Field bioassay tests conducted in Hilo, HI, using released flies and in Guatemala in a natural population showed that the polyethylene matrix panel became brittle and cracked during field exposure and that release rates of the attractants were relatively low. The coated cardboard panels were stable under field conditions and yielded high fly captures for up to 6 wk. Farma Tech commercial panels containing 12.3 and 23.4 g of trimedlure remained highly attractive throughout a 134-d test in Hawaii and appear to be a long-lasting alternative to panels coated with trimedlure in Stikem. The cost of the relatively high dose of trimedlure is offset by the prolonged active life of the panel. Commercial panels from AgriSense (10 g trimedlure and 10 g ceralure) released the attractants at a slower rate and were less attractive.

Animals↗
PubMed1992

Serum neurone-specific enolase levels in patients with neuroendocrine and carcinoid tumours.

We have examined concentrations of neurone-specific enolase (NSE) in sera from 18 patients with various neuroendocrine tumours, 26 patients with carcinoid tumours, 21 patients with non-neuroendocrine tumours and 37 control individuals. No statistically significant difference between the concentrations in patients with neuroendocrine tumours and patients with carcinoid tumours was found. However the NSE concentrations in patients with carcinoid and neuroendocrine tumours, when these two groups were combined, were significantly different from the patients with non-neuroendocrine tumours or the control individuals (P < or = 0.01). 38.5% of the patients with carcinoid tumours had raised NSE concentrations in serum; 55.5% of those with non carcinoid neuroendocrine tumours had raised concentrations. There appeared to be no correlation between the NSE concentrations and the extent of metastases.

Adult↗
PubMed1991

Serum neurone specific enolase (NSE) levels as an indicator of neuronal damage in patients with cerebral infarction.

A radioimmunoassay has been developed and used to measure serum neurone specific enolase (NSE) concentrations in 24 patients, following cerebral infarction. A significant correlation between cerebral infarct volume and maximum serum NSE concentration was observed (P = 0.047). Serum NSE was also assayed at times 24, 48, 72 and 96 h post ictus. At 72 h a significant correlation existed between serum NSE levels and infarct volume (P = 0.012), and levels appeared to be approaching statistical significance at 48 h (P = 0.067). No correlation existed at 24 and 96 h. In addition serum concentrations of NSE were compared to clinical outcome as determined by the Glasgow Outcome Score. Using the Mann-Whitney U test, there was no significant difference in maximum NSE level between patients graded 1-3 on the Glasgow Outcome Score and those graded 4 and 5. However, further studies are required on a larger population to more completely assess this. NSE may prove to be a useful marker of neuronal damage in the study of stroke, with particular application in the assessment of treatment.

Adult↗
PubMed1990

Development of a radioimmunoassay for neurone specific enolase (NSE) and its application in the study of patients receiving intra hepatic arterial streptozotocin and floxuridine.

A radioimmunoassay has been developed for neurone specific enolase (NSE) and used to measure serum NSE levels in patients with neuroendocrine and non-neuroendocrine tumours following intra hepatic arterial chemotherapy. Ten patients were studied, 7 receiving streptozotocin and floxuridine for neuroendocrine tumours and three receiving cisplatinum for non-neuroendocrine neoplasms. All ten patients had liver metastases. In patients with tumours of neuroendocrine origin, a significant increase in serum NSE was recorded within 24 h of therapy. Slight increases in serum NSE levels were also recorded in three patients with non neuroendocrine tumours. These increases may reflect lysis of neuroendocrine cells within the tumour. Raised levels in non-neuroendocrine tumour patients may reveal damage done to healthy neuronal and neuroendocrine cells during treatment. NSE may be a useful marker of the extent of cell death following chemotherapy.

Animals↗
PubMed1982

Coccidioidal pulmonary cavities with rupture.

Twenty-three patients with spontaneous rupture of a pulmonary cavity with a pyopneumothorax resulting from coccidioidomycosis are presented. Clinical and laboratory findings, medical and surgical treatment, and complications are detailed. Skin tests are not helpful in making a diagnosis. Although complement fixation titers were elevated in all patients and cultures were positive in 21, these laboratory tests should not delay surgical treatment. Surgical treatment included seven lobectomies, thirteen partial lobectomies, and one pneumonectomy. Two patients did not undergo surgical resection. Seventeen required some degree of decortication. There were three major complications and no deaths. Prompt operation is recommended when the diagnosis is suspected. Reasons for postponement include delay in seeking treatment, poorly controlled diabetes, and other complicating medical factors. The extent of surgical resection may have to be limited because of the extensive contamination of the pleural space. Amphotericin B was administered in 10 patients. The drug should be administered when the cavity ruptures in the acute phase of the disease, in all patients with diabetes, in delayed operations, in patients with concomitant medical problems, and when the extent of resection is limited to obtain immediate obliteration of the pleural space.

Adolescent↗