150 research outputs found
Torsades de pointes during laparoscopic adrenalectomy of a pheochromocytoma: a case report
<p>Abstract</p> <p>Introduction</p> <p>Torsades de pointes is a rare but potentially lethal arrhythmia. The amount of literature available on Torsades de pointes occurring in patients with pheochromocytoma is limited, and we found no literature describing this dysrhythmia in a patient with pheochromocytoma under anesthesia.</p> <p>Case presentation</p> <p>We describe the case of a 42-year-old Caucasian woman without QT prolongation preoperatively with recurrent Torsades de pointes during laparoscopic removal of a pheochromocytoma. Torsades de pointes mainly occurs in the setting of a prolonged QT interval. This patient neither had a prolonged QT preoperatively nor was her family history suspect for a congenital long QT syndrome. Most likely, our patient had an acquired long QT syndrome, elicited by the combination of flecainide, hypomagnesemia and adrenergic stimulation during manipulation of the tumor.</p> <p>Conclusion</p> <p>We show that in the case of a surgical pheochromocytoma removal, perioperative conditions can elicit an acquired or previously unknown congenital long QT syndrome. Therefore, preoperative Ξ±- and Ξ²-blockade is advised, QT-prolonging drugs should be avoided and potassium and magnesium plasma levels should be kept at normal to high levels.</p
Cyclic Vomiting Syndrome in 41 adults: the illness, the patients, and problems of management
BACKGROUND: Cyclic Vomiting Syndrome (CVS) is a disorder characterized by recurrent, stereotypic episodes of incapacitating nausea, vomiting and other symptoms, separated by intervals of comparative wellness. This report describes the clinical features, co-morbidities and problems encountered in management of 41 adult patients who met the diagnostic criteria for CVS. METHODS: This is a retrospective study of adults with CVS seen between 1994 and 2003. Follow-up data were obtained by mailed questionnaires. RESULTS: Age of onset ranged from 2 to 49 years. The duration of CVS at the time of consultation ranged from less than 1 year to 49 years. CVS episodes were stereotypic in respect of their hours of onset, symptomatology and length. Ninety-three percent of patients had recognizable prodromes. Half of the patients experienced a constellation of symptoms consisting of CVS episodes, migraine diathesis, inter-episodic dyspeptic nausea and a history of panic attacks. Deterioration in the course of CVS is indicated by coalescence of episodes in time. The prognosis of CVS is favorable in the majority of patients. CONCLUSION: CVS is a disabling disorder affecting adults as well as children. Because its occurrence in adults is little known, patients experience delayed or mis-diagnosis and ineffectual, sometimes inappropriately invasive management
Rapidly measured indicators of recreational water quality and swimming-associated illness at marine beaches: a prospective cohort study
<p>Abstract</p> <p>Introduction</p> <p>In the United States and elsewhere, recreational water quality is monitored for fecal indicator bacteria to help prevent swimming-associated illnesses. Standard methods to measure these bacteria take at least 24 hours to obtain results. Molecular approaches such as quantitative polymerase chain reaction (qPCR) can estimate these bacteria faster, in under 3 hours. Previously, we demonstrated that measurements of the fecal indicator bacteria <it>Enterococcus </it>using qPCR were associated with gastrointestinal (GI) illness among swimmers at freshwater beaches. In this paper, we report on results from three marine beach sites.</p> <p>Methods</p> <p>We interviewed beach-goers and collected water samples at marine beaches affected by treated sewage discharges in Mississippi in 2005, and Rhode Island and Alabama in 2007. Ten to twelve days later, we obtained information about gastrointestinal, respiratory, eye, ear and skin symptoms by telephone. We tested water samples for fecal indicator organisms using qPCR and other methods.</p> <p>Results</p> <p>We enrolled 6,350 beach-goers. The occurrence of GI illness among swimmers was associated with a log<sub>10</sub>-increase in exposure to qPCR-determined estimates of fecal indicator organisms in the genus <it>Enterococcus </it>(AOR = 2.6, 95% CI 1.3-5.1) and order <it>Bacteroidales </it>(AOR = 1.9, 95% CI 1.3-2.9). Estimates of organisms related to <it>Clostridium perfringens </it>and a subgroup of organisms in the genus <it>Bacteroides </it>were also determined by qPCR in 2007, as was F+ coliphage, but relationships between these indicators and illness were not statistically significant.</p> <p>Conclusions</p> <p>This study provides the first evidence of a relationship between gastrointestinal illness and estimates of fecal indicator organisms determined by qPCR at marine beaches.</p
The analysis of PIK3CA mutations in gastric carcinoma and metanalysis of literature suggest that exon-selectivity is a signature of cancer type
BACKGROUND: PIK3CA is one of the genes most frequently mutated in human cancers and it is a potential target for personalized therapy. The aim of this study was to assess the frequency and type of PIK3CA mutations in gastric carcinoma and compare them with their clinical pathological correlates. METHODS: We analysed 264 gastric cancers, including 39 with microsatellite instability (MSI), for mutations in the two PIK3CA hotspots in exons 9 and 20 by direct sequencing of DNA obtained from microdissected cancer cells. RESULTS: The cases harbouring mutations were 42 (16%). All were heterozygous missense single base substitutions; the most common was H1047R (26/42; 62%) in exon 20 and the second was Q546K (4/42; 9.5%) in exon 9. All the mutated MSI cases (8/39) carried the H1047R mutation. No other association between PI3KCA mutations and clinical pathological covariates was found. A metanalysis of the mutations occurring in the same regions in 27 publications showed that ratio between exon 20 and exon 9 prevalences was 0.6 (95% CI: 0.5 -0.8) for colon, 1.6 (95% CI: 1.1 -2.3) for breast, 2.7 (95% CI: 1.6 -4.9) for gastric and 4.1 (95% CI: 1.9 -10.3) for endometrial cancer. CONCLUSIONS: The overall prevalence of PIK3CA mutations implies an important role for PIK3CA in gastric cancer. The lack of association with any clinical-pathological condition suggests that mutations in PIK3CA occur early in the development of cancer. The metanalysis showed that exon-selectivity is an important signature of cancer type reflecting different contexts in which tumours arise
Longer Leukocyte Telomere Length Is Associated with Smaller Hippocampal Volume among Non-Demented APOE Ξ΅3/Ξ΅3 Subjects
Telomere length shortens with cellular division, and leukocyte telomere length is used as a marker for systemic telomere length. The hippocampus hosts adult neurogenesis and is an important structure for episodic memory, and carriers of the apolipoprotein E Ξ΅4 allele exhibit higher hippocampal atrophy rates and differing telomere dynamics compared with non-carriers. The authors investigated whether leukocyte telomere length was associated with hippocampal volume in 57 cognitively intact subjects (29 Ξ΅3/Ξ΅3 carriers; 28 Ξ΅4 carriers) aged 49β79 yr. Leukocyte telomere length correlated inversely with left (rsβ=ββ0.465; pβ=β0.011), right (rsβ=ββ0.414; pβ=β0.025), and total hippocampus volume (rsβ=ββ0.519; pβ=β0.004) among APOE Ξ΅3/Ξ΅3 carriers, but not among Ξ΅4 carriers. However, the Ξ΅4 carriers fit with the general correlation pattern exhibited by the Ξ΅3/Ξ΅3 carriers, as Ξ΅4 carriers on average had longer telomeres and smaller hippocampi compared with Ξ΅3/Ξ΅3 carriers. The relationship observed can be interpreted as long telomeres representing a history of relatively low cellular proliferation, reflected in smaller hippocampal volumes. The results support the potential of leukocyte telomere length being used as a biomarker for tapping functional and structural processes of the aging brain
Suppression of Osteosarcoma Cell Invasion by Chemotherapy Is Mediated by Urokinase Plasminogen Activator Activity via Up-Regulation of EGR1
Background: The cellular and molecular mechanisms of tumour response following chemotherapy are largely unknown. We
found that low dose anti-tumour agents up-regulate early growth response 1 (EGR1) expression. EGR1 is a member of the
immediate-early gene group of transcription factors which modulate transcription of multiple genes involved in cell
proliferation, differentiation, and development. It has been reported that EGR1 act as either tumour promoting factor or
suppressor. We therefore examined the expression and function of EGR1 in osteosarcoma.
Methods: We investigated the expression of EGR1 in human osteosarcoma cell lines and biopsy specimens. We next
examined the expression of EGR1 following anti-tumour agents treatment. To examine the function of EGR1 in
osteosarcoma, we assessed the tumour growth and invasion in vitro and in vivo.
Results: Real-time PCR revealed that EGR1 was down-regulated both in osteosarcoma cell lines and osteosarcoma patientsβ
biopsy specimens. In addition, EGR1 was up-regulated both in osteosarcoma patientβ specimens and osteosarcoma cell lines
following anti-tumour agent treatment. Although forced expression of EGR1 did not prevent osteosarcoma growth, forced
expression of EGR1 prevented osteosarcoma cell invasion in vitro. In addition, forced expression of EGR1 promoted downregulation
of urokinase plasminogen activator, urokinase receptor, and urokinase plasminogen activity. Xenograft mice
models showed that forced expression of EGR1 prevents osteosarcoma cell migration into blood vessels.
Conclusions: These findings suggest that although chemotherapy could not prevent osteosarcoma growth in
chemotherapy-resistant patients, it did prevent osteosarcoma cell invasion by down-regulation of urokinase plasminogen
activity via up-regulation of EGR1 during chemotherapy periods
No iron fertilization in the equatorial Pacific Ocean during the last ice age
The equatorial Pacific Ocean is one of the major high-nutrient, low-chlorophyll regions in the global ocean. In such regions, the consumption of the available macro-nutrients such as nitrate and phosphate is thought to be limited in part by the low abundance of the critical micro-nutrient iron1. Greater atmospheric dust deposition2 could have fertilized the equatorial Pacific with iron during the last ice ageβthe Last Glacial Period (LGP) but the effect of increased ice-age dust fluxes on primary productivity in the equatorial Pacific remains uncertain. Here we present meridional transects of dust (derived from the 232Th proxy), phytoplankton productivity (using opal, 231Pa/230Th and excess Ba), and the degree of nitrate consumption (using foraminifera-bound Ξ΄15N) from six cores in the central equatorial Pacific for the Holocene (0β10,000 years ago) and the LGP (17,000β27,000 years ago). We find that, although dust deposition in the central equatorial Pacific was two to three times greater in the LGP than in the Holocene, productivity was the same or lower, and the degree of nitrate consumption was the same. These biogeochemical findings suggest that the relatively greater ice-age dust fluxes were not large enough to provide substantial iron fertilization to the central equatorial Pacific. This may have been because the absolute rate of dust deposition in the LGP (although greater than the Holocene rate) was very low. The lower productivity coupled with unchanged nitrate consumption suggests that the subsurface major nutrient concentrations were lower in the central equatorial Pacific during the LGP. As these nutrients are today dominantly sourced from the Subantarctic Zone of the Southern Ocean, we propose that the central equatorial Pacific data are consistent with more nutrient consumption in the Subantarctic Zone, possibly owing to iron fertilization as a result of higher absolute dust fluxes in this region7,8. Thus, ice-age iron fertilization in the Subantarctic Zone would have ultimately worked to lower, not raise, equatorial Pacific productivity
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