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S Hanley

Publications and source records attributed to S Hanley.

At least 19 recordsLinked to original sources
PubMed2006

Autocrine insulin action activates Akt and increases survival of isolated human islets.

AIMS/HYPOTHESIS: The phosphatidylinositol 3-kinase (PI3K)/Akt pathway plays a critical role in promoting the survival of pancreatic beta cells. Akt becomes activated in isolated human islets following overnight culture despite significant levels of cell death. The aim of the current study was to identify the cause of the observed increase in Akt phosphorylation in isolated islets. We hypothesised that a factor secreted by the islets in culture was acting in an autocrine manner to activate Akt. METHODS: In order to identify the stimulus of the PI3K/Akt pathway in culture, we examined the effects of different culture conditions on Akt phosphorylation and islet survival during the immediate post-isolation period. RESULTS: We demonstrated that islet-conditioned medium induced Akt phosphorylation in freshly isolated human islets, whereas frequent medium replacement decreased Akt phosphorylation. Following overnight culture, islet-conditioned medium contained significantly elevated levels of insulin, indicating that insulin may be responsible for the observed increase in Akt phosphorylation. Indeed, treatment with an anti-insulin antibody or with inhibitors of insulin receptor/IGF receptor 1 kinase activity suppressed Akt phosphorylation, leading to decreased islet survival. In addition, dispersion of islets into single cells also suppressed Akt phosphorylation and induced islet cell death, indicating that islet integrity is also required for maximal Akt phosphorylation. CONCLUSIONS/INTERPRETATION: Our findings demonstrate that insulin acts in an autocrine manner to activate Akt and mediate the survival of isolated human islets. These findings provide new information on how culturing islets prior to transplantation may be beneficial to their survival by allowing for autocrine activation of the pro-survival Akt pathway.

Cadaver↗
PubMed2005

Morphogenetic plasticity of adult human pancreatic islets of Langerhans.

The aim of this study was to investigate the phenotypic plasticity of pancreatic islets of Langerhans. Quiescent adult human islets were induced to undergo a phenotypic switch to highly proliferative duct-like structures in a process characterized by a loss of expression of islet-specific hormones and transcription factors as well as a temporally related rise in the expression of markers of both duct epithelial and progenitor cells. Short-term treatment of these primitive duct-like structures with the neogenic factor islet neogenesis-associated protein (INGAP104-118) induced their reconversion back to islet-like structures in a PI3-kinase-dependent manner. These neoislets resembled freshly isolated human islets with respect to the presence and topological arrangement of the four endocrine cell types, islet gene expression and hormone production, insulin content and glucose-responsive insulin secretion. Our results suggest that adult human islets possess a remarkable degree of morphogenetic plasticity. This novel observation may have important implications for understanding pancreatic carcinogenesis and islet neogenesis.

Adult↗
PubMed2001

Gene structure and promoter function of a teleost ribosomal protein: a tilapia (Oreochromis mossambicus) L18 gene.

We have cloned and characterized a tilapia (Oreochromis mossambicus) L18 ribosomal protein gene, including the complete transcribed region and 488 bp of upstream regulatory sequences. We have also isolated two L18 cDNAs from another tilapia (Oreochromis niloticus) with a few conservative nucleotide differences. Our results suggest the presence of two genes in both species. Reporter constructs were tested for transient expression in CV1 cells and in microinjected zebrafish and tilapia embryos. The tilapia L18 promoter was able to drive expression of the reporter gene in all three experiments, with no apparent preference for a particular tissue. The tilapia L18 promoter is therefore likely to be a powerful tool to drive tissue-independent gene expression in fish.

Amino Acid Sequence↗
PubMed2001

Evaluation of a PCR/DNA probe colorimetric membrane assay for identification of Campylobacter spp. in human stool specimens.

DNA was extracted from 50 human stool specimens using the QIAamp DNA stool minikit. PCR amplification was followed by post-PCR hybridization to DNA probes specific for the Campylobacter genus, Campylobacter jejuni, and Campylobacter coli in a colorimetric membrane assay. Thirty-two of 38 culture-positive specimens were PCR/DNA probe positive for C. jejuni. The assay is rapid and simple and can be applied to stool specimens for the detection of Campylobacter.

Campylobacter↗
PubMed2000

Identification of transposon-tagged genes by the random sequencing of Mutator-tagged DNA fragments from Zea mays.

We have used a universal adaptor amplification procedure to isolate random Mutator-tagged fragments from Mutator-active maize plants. Direct sequence characterization of 761 Mutator-tagged fragments indicated that a significant number were homologous to sequences within the public databases. The ability of Mutator-tagged fragments to detect homology was not related to the length of the sequence within the range 100-400 bp. However, fragments above this size did show an increased chance of detecting homology to either expressed sequence tags or genes. Characterization of the insertion sites of the Mutator elements suggested that while it does target transcribed regions, Mutator does not appear to have any site preference within the transcription unit. Hybridization of previously unidentified Mutator-tagged fragments to arrayed cDNA libraries confirmed that many of these also showed homology to transcribed regions of the genome. Examination of back-crossed progeny confirmed that all the insertions examined were germinal; however, in all but one case, selfing five individual Mutator-tagged lines failed to reveal an obvious phenotype. This study suggests that the random sequencing of Mutator-tagged fragments is capable of producing both a significant number of interesting transposon tagged genes and mutant plant lines, all of which could be extremely valuable in future gene discovery and functional genomics programmes.

Amino Acid Sequence↗
PubMed1998

Differentiation of desquamative interstitial pneumonia (DIP) from pulmonary adenocarcinoma by immunocytochemistry.

AIM: After a misdiagnosis of pulmonary adenocarcinoma as desquamative interstitial pneumonia (DIP), we investigated whether immunohistochemical markers could differentiate these conditions. METHODS AND RESULTS: Three cases of DIP and one pulmonary adenocarcinoma masquerading as DIP were studied by light and electron microscopy. All cases were mucin-negative. The cases of DIP were CD68 positive but cytokeratin-negative. The adenocarcinoma was cytokeratin-positive (AE1/3 and CAM5.2), as well as showing some CD68-positive cells. Markers for carcinoma (CEA, Ber-EP4, and Leu M1) were negative in all cases. Ultrastructurally the adenocarcinoma appeared to be derived from Type II pneumocytes. CONCLUSION: Before a diagnosis of DIP is made, cytokeratin markers should be used.

Adenocarcinoma↗
PubMed1998

Isolation and functional analysis of the histone H3 promoter from atlantic salmon (Salmo salar L.).

The histone H3 (sH3) promoter of Atlantic salmon (Salmo salar) was cloned via polymerase chain reaction using primers designed from the rainbow trout (Oncorhynchus mykiss) promoter sequence. A comparison of the nucleotide sequence with the equivalent sequences from rainbow trout and sockeye salmon (Oncorhynchus nerka) revealed a high degree of conservation. In vivo expression analysis of the sH3 promoter was carried out in both rainbow trout and zebrafish (Danio rerio) embryos. A direct comparison of the sH3 promoter with the viral RSV promoter in rainbow trout resulted in stronger expression of the sH3 promoter. Furthermore, lacZ expression directed by the sH3 promoter was ubiquitous in several different cell types in developing zebrafish embryos. These results suggest that the sH3 promoter will be useful in transgenic studies in Atlantic salmon.

Animals↗
PubMed1997

Oral transmucosal fentanyl citrate as an additional premedicant for adult cardiac surgery patients.

OBJECTIVE: To investigate the efficacy of a combination of midazolam and oral transmucosal fentanyl citrate (OTFC) as a preoperative medication for adult cardiac surgery patients compared with the use of midazolam alone. DESIGN: A randomized, prospective study. SETTING: University teaching hospital. PARTICIPANTS: Patients scheduled for elective coronary artery bypass surgery. INTERVENTIONS: All patients were given 50 micrograms/kg of midazolam intramuscularly in their rooms. Group I received 300 micrograms of OTFC Oralet (Anesta Corp, Salt Lake City, UT) if they weighed less than 70 kg and 400 micrograms of OTFC Oralet if they weighed more than 70 kg. Group II received a placebo Oralet. A radial artery catheter, two internal jugular venous catheters, and a pulmonary artery catheter inserted through one of the internal jugular catheters were placed in each study patient. Fentanyl was administered intravenously as a rescue drug. MEASUREMENTS AND MAIN RESULTS: Ninety percent of midazolam/OTFC patients reported feeling no pain during catheter placement, compared with 50% of midazolam/placebo patients. Fifty percent of the placebo group required fentanyl supplement of 50 micrograms intravenously because of complaints of pain, compared with 10% of the OTFC group. The midazolam/OTFC group scored approximately 20% better than the placebo group in the independent observer score of patient analgesia and the anesthesiologist rating for ease of invasive catheter placement. No myocardial ischemic events were noted in either group as determined by electrocardiogram. All patients found the Oralet mode of delivery very acceptable. CONCLUSIONS: The OTFC Oralet provides effective analgesia and sedation when combined with midazolam for invasive catheter placement in adult cardiac surgery patients. The OTFC Oralet with its gradual onset lessens the possibility of overmedicating with fentanyl, and it offers a very acceptable mode of delivery for a preemptive analgesic.

Administration, Oral↗
PubMed1995

Sequence analysis and evolutionary aspects of piscine alpha-1-microglobulin/bikunin mRNA transcripts.

Studies on mammalian alpha-1-microglobulin/bikunin (AMBP) protein sequences suggest the ancestral AMBP gene arose between 270 and 80 million years ago. Here we report a similar study including recently reported piscine AMBP messenger RNA sequences. The analysis implies a far earlier data for the assembly of the ancestral AMBP gene, more than 450 million years ago. Similarly, a revised date for the origin of the ancestral Kunitz-type protein is estimated at approximately 875 million years ago. Evolutionary conservation is apparent among all the AMBP amino acid sequences. This implies a common functional significance in both teleosts and mammals. However, an unusually rapid rate of evolution is observed for domain II of the piscine bikunin sequences, suggesting that this domain is no longer truly orthologous in fish.

Alpha-Globulins↗
PubMed1995

Chemotherapy with vincristine/ifosfamide/carboplatin/etoposide in small cell lung cancer.

Although chemotherapy is considered the cornerstone of treatment for small cell lung cancer (SCLC), the majority of SCLC patients relapse and die of their disease within 2 years of diagnosis. Until newer, more effective drugs are developed, both optimization of available chemotherapeutic regimens and the use of combined chemotherapy/radiotherapy will be required to improve the survival of SCLC patients. Combining ifosfamide, carboplatin, and etoposide, among the most active single agents against SCLC, into the ICE regimen was a logical move that has resulted in improved response and survival rates. In limited and extensive SCLC, respectively, ICE and ICE administered with vincristine (VICE) have achieved overall response rates of 79% to 94% and 77% to 100% and 2-year survival rates of 24% to 33% and 9% to 25%, respectively. Treatment-related toxicities, especially myelosuppression, have hindered efforts to accelerate the administration of ICE and VICE regimens and to incorporate them into combined-modality treatments. However, the use of hematologic support measures, including growth factors and peripheral blood progenitor cells, may pave the way for maximizing the effectiveness of these regimens.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Sequence of a cDNA clone encoding the Atlantic salmon alpha 1-microglobulin/bikunin protein.

We report here the nucleotide sequence of a cDNA clone encoding the salmon (Salmo salar) alpha 1-microglobulin/bikunin precursor protein (sAMBP). The encoded precursor shows 36 and 42% amino acid (aa) similarity to the AMBP of pig and human, respectively. Signature aa motifs are conserved. The data infer that the ancestral AMBP gene arose more than 450 million years ago, before the tetrapod-fish divergence.

Alpha-Globulins↗
PubMed1992

Cloning, genetic mapping, and expression analysis of an Arabidopsis thaliana gene that encodes 1-aminocyclopropane-1-carboxylate synthase.

A genomic clone of one member of the Arabidopsis thaliana (L.) Heynh. 1-aminocyclopropane-1-carboxylate (ACC) synthase (S-adenosyl-L-methionine methylthioadenosine-lyase, EC 4.4.1.14) gene family (AT-ACC1) was isolated and sequenced. A region of homology was found in the 5'-untranslated region with the promoter of a zucchini and a tomato ACC synthase gene. Comparison of its primary structure with other ACC synthases revealed conservation of seven peptide regions as well as similarity with 11 amino acids of the catalytic site of aminotransferases. Genomic DNA gel blotting suggested the existence of an ACC synthase multigene family in Arabidopsis, possibly with three other members, none of which is very closely related to AT-ACC1. The existence of at least one other gene was confirmed by the isolation of a cDNA (AT-ACC2) from a flower-specific cDNA library. The AT-ACC1 gene was mapped on the Arabidopsis restriction fragment length polymorphism map and is located on the top of chromosome 1. This position does not correspond to any known mutation on the genetic map. Expression of the AT-ACC1 gene was studied by reverse transcription-PCR on total RNA. Messenger accumulation was strong in young leaves and flowers. The gene was not induced by wounding of young leaves or in seedlings in the presence of auxin. Ethylene exposure of mature plants led to an induction of AT-ACC1 gene expression. It is suggested that AT-ACC1 protein has a role in developmental control of ethylene synthesis.

Amino Acid Sequence↗
PubMed1992

Effects of ionizing radiation on a plant genome: analysis of two Arabidopsis transparent testa mutations.

Ionizing radiation is known to cause chromosomal alterations such as inversions and deletions and has been used extensively for inducing mutations. In Arabidopsis, two methods for the isolation of genes identified on the basis of mutant phenotypes--genomic subtraction and chromosome walking--either rely on or are greatly facilitated by the availability of these types of mutations. This article gives a detailed characterization of ionizing radiation-induced mutations in plants. The Arabidopsis genes encoding chalcone flavanone isomerase (CHI) and dihydroflavonol 4-reductase (DFR) were cloned and found to correspond to two transparent testa loci. A CHI allele, generated by fast-neutron irradiation, consisted of an inversion within the gene. A 272-bp fragment from 38 centimorgans away on the same chromosome was transferred to one end of this inversion. A DFR allele, induced by x-irradiation, contained two deletions and an inversion of the 2.8-centimorgan intervening region. Sequence analysis of the break points in both mutants indicate that repair of radiation-induced damage involves mechanisms similar or identical to those that mediate the integration of foreign sequences into the genome. The chromosome rearrangements found in these mutants have important implications for the use of ionizing radiation-induced alleles in classical and molecular genetic experiments in plants.

Alcohol Oxidoreductases↗
PubMed1991

Mapping the Arabidopsis genome.

We are engaged in a project to assemble a complete physical map of the Arabidopsis thaliana (L.) Heynh. genome. The first stage of this project involved the analysis of approximately 20,000 random cosmid clones representing an 8- to 10-fold sampling redundancy. Using computer matching programs, these clones have been assembled into some 750 contigs, encompassing 90-95% of the Arabidopsis genome. We are currently attempting to bridge the gaps by selecting the missing clones by hybridization. As a complement to this project we have constructed an RFLP map which currently contains 175 markers. The RFLP map provides contact points between the physical map and classical genetic map. Our main objective for undertaking this project is to simplify the cloning of genes where only the locus and not the product of the gene is known. In other words, the combined RFLP/physical map serves as a general cloning tool by simplifying the movement from the genetic locus to the cloned gene.

Abscisic Acid↗
PubMed1986

Bioavailability in rats of human recombinant tissue plasminogen activator after subcutaneous and intramuscular injection.

The bioavailability of human recombinant tissue plasminogen activator (rt-PA) in rats was measured after subcutaneous (s.c.) and intramuscular (i.m.) injection. Rt-PA was absorbed after both i.m. and s.c. injection, giving peak plasma concentrations within 30 min and 1 h, respectively, with detectable concentrations up to 6 h. These peak values of bioavailable t-PA were obtained in a functional fibrin plate assay of euglobulin precipitates and expressed as +88% and +243% (for s.c. and i.m. routes respectively) above basal rat fibrinolytic activity. Prior injection of rt-PA, s.c. or i.m., significantly reduced the weights of thrombi induced in the inferior vena cava after injection.

Animals↗