Biomedical subjects

G Sutton

Publications and source records attributed to G Sutton.

At least 19 recordsLinked to original sources

PubMed2006

Eukaryotic expression: developments for structural proteomics.

The production of sufficient quantities of protein is an essential prelude to a structure determination, but for many viral and human proteins this cannot be achieved using prokaryotic expression systems. Groups in the Structural Proteomics In Europe (SPINE) consortium have developed and implemented high-throughput (HTP) methodologies for cloning, expression screening and protein production in eukaryotic systems. Studies focused on three systems: yeast (Pichia pastoris and Saccharomyces cerevisiae), baculovirus-infected insect cells and transient expression in mammalian cells. Suitable vectors for HTP cloning are described and results from their use in expression screening and protein-production pipelines are reported. Strategies for co-expression, selenomethionine labelling (in all three eukaryotic systems) and control of glycosylation (for secreted proteins in mammalian cells) are assessed.

Animals↗

PubMed2004

The Warfarin/Aspirin Study in Heart failure (WASH): a randomized trial comparing antithrombotic strategies for patients with heart failure.

BACKGROUND: Heart failure is commonly associated with vascular disease and a high rate of athero-thrombotic events, but the risks and benefits of antithrombotic therapy are unknown. METHODS: The current study was an open-label, randomized, controlled trial comparing no antithrombotic therapy, aspirin (300 mg/day), and warfarin (target international normalized ratio 2.5) in patients with heart failure and left ventricular systolic dysfunction requiring diuretic therapy. The primary objective was to demonstrate the feasibility and inform the design of a larger outcome study. The primary clinical outcome was death, nonfatal myocardial infarction, or nonfatal stroke. RESULTS: Two hundred seventy-nine patients were randomized and 627 patient-years exposure were accumulated over a mean follow-up time of 27 +/- 1 months. Twenty-six (26%), 29 (32%), and 23 (26%) patients randomized to no antithrombotic treatment, aspirin, and warfarin, respectively, reached the primary outcome (ns). There were trends to a worse outcome among those randomized to aspirin for a number of secondary outcomes. Significantly (P =.044) more patients randomized to aspirin were hospitalized for cardiovascular reasons, especially worsening heart failure. CONCLUSIONS: The Warfarin/Aspirin Study in Heart failure (WASH) provides no evidence that aspirin is effective or safe in patients with heart failure. The benefits of warfarin for patients with heart failure in sinus rhythm have not been established. Antithrombotic therapy in patients with heart failure is not evidence based but commonly contributes to polypharmacy.

Aged↗

PubMed2003

Corneal replacement using a synthetic hydrogel cornea, AlphaCor: device, preliminary outcomes and complications.

PURPOSE: Clinical assessment of outcome of corneal replacement with a synthetic cornea, AlphaCor, in patients considered at too high risk for conventional penetrating keratoplasty with donor tissue to be successful, but excluding indications such as end-stage dry eye that might be suited to traditional prosthokeratoplasty. METHODS: All patients in the multicentre clinical trial were managed according to an approved protocol, with Ethics Committee approval in each centre. Preoperative visual acuity ranged from perception of light (PL) to 6/60 (20/200). Implantation was by means of an intralamellar technique, with a conjunctival flap in most cases. Tissues anterior to the optic were removed as a secondary procedure. RESULTS: Up to 30 November 2001, 40 AlphaCor devices had been implanted in 38 patients, of mean age 60 years. Follow-up ranged from 0.5 months to 3 years. There had been one extrusion (2.5%) and four cases (10%) where a device had been removed due to melt-related complications. All five of these cases received a donor corneal graft after the device was removed, with these grafts remaining anatomically satisfactory and epithelialised to date. Corneal melts in AlphaCor recipients were found to be strongly associated with a history of ocular herpes simplex infection. Two further devices (5%) were removed owing to reduced optic clarity after presumed drug-related deposition, and have been successfully replaced with second devices. Mean preoperative best-corrected visual acuity was hand movements. Visual acuities after surgery ranged from PL to 6/6(-2) (20/20(-2)). CONCLUSIONS: Early results suggest that the AlphaCor, previously known as the Chirila keratoprosthesis (Chirila KPro), has a low incidence of the complications traditionally associated with keratoprostheses and can be effective in restoring vision in patients considered untreatable by conventional corneal transplantation. Importantly, the device can be replaced with a donor graft in the event of development of a significant complication. A history of ocular herpes simplex is a contraindication to AlphaCor implantation. Ongoing monitoring of clinical outcomes in all patients will allow the indications for AlphaCor, as opposed to donor grafts, to be determined.

Adult↗

PubMed2001

Routine breast screening for women aged 65-69: results from evaluation of the demonstration sites.

Routine programme data and specially designed surveys from 3 demonstration sites were analysed to determine the implications of extending the NHS Breast Screening Programme (NHSBSP), to include routine invitations for women up to 69 years. All women aged 65-69 and registered with GPs in these areas received routine invitations for breast screening along with those aged 50-64. Overall uptake was 71% in women aged 65-69 compared with 78% in younger women, but was > or = 90% in both groups who had previously attended within 5 years. Recall rates were lower for older women, but with a higher positive predictive value for cancer. The percentages of invasive cancer in different prognostic categories were similar in the 2 age groups. Older women took no longer to screen than younger women. The costs per woman invited or per woman screened were also similar to those for women aged 50-64, whilst the cost per cancer detected was some 34% lower in older women. Breast screening is as cost effective for women aged 65-69 as for those aged 50-64, with a higher cancer detection rate balancing shorter life expectancy. The proposed extension to the national programme will have considerable workforce implications for the NHSBSP and require additional resources.

Aged↗

PubMed2001

Phase I trial of escalating doses of paclitaxel combined with fixed doses of cisplatin and doxorubicin in advanced endometrial cancer and other gynecologic malignancies: a Gynecologic Oncology Group study.

PURPOSE: The primary objective of this phase I trial was to determine the feasibility of administering a combination of paclitaxel, cisplatin, and doxorubicin with or without granulocyte colony-stimulating factor (G-CSF) in patients with advanced endometrial and other gynecologic cancers. PATIENTS AND METHODS: Patients were chemotherapy-naive. Doxorubicin was administered as a brief infusion, paclitaxel for 3 hours, and cisplatin for 60 minutes. Treatments were repeated every 3 weeks. For most dose levels, the cisplatin and doxorubicin were fixed at 60 mg/m(2) and 45 mg/m(2), whereas the paclitaxel was escalated in successive cohorts from 90 to 250 mg/m(2). Patients who had received previous radiotherapy to the whole pelvis were escalated separately from those who had not. RESULTS: Eighty patients received 320 cycles of therapy. When G-CSF was not used, myelosuppression prevented escalation beyond the starting dose for patients with or without previous pelvic radiotherapy. When G-CSF was added, neurotoxicity became dose-limiting for both groups. Ten patients were removed from the study for asymptomatic declines in ejection fraction, but no symptomatic congestive heart failure was observed. Major antitumor responses occurred in 46% of patients (six of 13) with measurable endometrial carcinoma and 50% of patients (eight of 16) with measurable cervical carcinoma. CONCLUSION: The combination of paclitaxel, doxorubicin, and cisplatin at relevant single-agent doses is active and feasible with the addition of G-CSF. A regimen of cisplatin 60 mg/m(2), doxorubicin 45 mg/m(2), and paclitaxel 160 mg/m(2) with G-CSF support is recommended for further testing.

Adult↗

PubMed2001

Should ambulant patients be directed to reception or triage first?

OBJECTIVES: Developments in triage have led to patients being directed to triage rather than reception upon arrival in A&E. This study aimed to discover if attending triage or reception first, was preferable in terms of timeliness, clarity and safety. METHODS: The study compared two consecutive four week periods during which patients were directed to attend triage first and then reception first. Observers recorded their actions on arrival. Questionnaires recorded the patients' perceptions of each strategy. High priority triage categories were audited during the reception first phase. RESULTS: 1850 patients were observed in the triage first phase with a mean door to triage time of 10.6 minutes, triage to reception 5.3 minutes and door to reception 15.8 minutes. A total of 1522 patients were observed in the reception first phase with a mean door to reception time of 0.5 minutes, reception to triage 12.4 minutes and door to triage of 12.9 minutes. Patients were more likely to present to the appropriate place during the reception first phase (88% versus 34%) and reported better understanding of instructions. No case given triage category one or two suffered an adverse outcome resulting from delay associated with attending reception first. CONCLUSION: Directing patients to attend reception first is timely and less confusing. It is safe provided booking in does not delay assessment by more than 15 minutes.

Efficiency, Organizational↗

PubMed2000

N-methyl D-aspartate receptor-mediated bidirectional control of extracellular signal-regulated kinase activity in cortical neuronal cultures.

N-Methyl D-aspartate (NMDA) receptor activation of extracellular-signal regulated kinase (ERK) was examined in primary cortical cultures. Tetrodotoxin, NMDA receptor antagonists, or reduced extracellular calcium (0.1 mm) greatly decreased basal levels of phospho-ERK2, indicating that activity-dependent activation of NMDA receptors maintained a high level of basal ERK2 activation. This activity-dependent activation of phospho-ERK2 was blocked by pertussis toxin and inhibition of calcium/calmodulin-dependent kinase II and phosphatidylinositol 3-kinase but not by inhibition of protein kinase C or cAMP-dependent protein kinase. Addition of a calcium ionophore or 100 microm NMDA decreased phospho-ERK2 in the presence of 1 mm extracellular calcium but enhanced phospho-ERK2 in 0.1 mm extracellular calcium. The reduction in basal phospho-ERK2 by 100 microm NMDA was also reflected as a decrease in phospho-cAMP response element-binding protein. Inhibition of tyrosine phosphatases and serine/threonine phosphatases protein phosphatase 1 (PP1), PP2A, and PP2B did not prevent the inhibitory effect of NMDA. In the presence of tetrodotoxin, NMDA produced a bell-shaped dose-response curve with stimulation of phospho-ERK2 at 10, 25, and 50 microm NMDA and reduced stimulation at 100 microm NMDA. NMDA (50 microm) stimulation of phospho-ERK2 was completely blocked by pertussis toxin and inhibitors of phosphatidylinositol 3-kinase and was partially blocked by a calcium/calmodulin-dependent kinase II inhibitor. These results suggests that NMDA receptors can bidirectionally control ERK signaling.

Animals↗

PubMed2000

An old friend

Explore the source record for details and available documents.

Journal Article↗

PubMed2000

A phase III trial of ifosfamide with or without cisplatin in carcinosarcoma of the uterus: A Gynecologic Oncology Group Study.

OBJECTIVE: The aims of this study were to substantiate the previously reported activity of ifosfamide in patients with advanced, persistent, or recurrent carcinosarcoma (mixed mesodermal sarcoma) of the uterus, and to determine whether the addition of cisplatin results in an improved response or survival. Secondarily, we sought to determine the toxicity of ifosfamide-cisplatin in this patient population. METHODS: Patients were randomized to receive ifosfamide (1.5 g/m(2)/day) times 5 days every 3 weeks for eight courses with mesna uroprotection, with or without cisplatin (20 mg/m(2)/day) times 5 days. No patient had received previous chemotherapy. RESULTS: Of 224 patients entered on this study, 30 were ineligible for a variety of reasons, leaving 194 evaluable patients. Early in the study, the dose of the combination regimen was reduced by 20% (1 day) because of toxicity. The investigational arms were balanced for age, grade, and Gynecologic Oncology Group performance status. Percentages of adverse effects reported in 191 patients receiving chemotherapy included (ifosfamide/cisplatin-ifosfamide) grade 3 or 4 granulocytopenia (36/60), grade 3 or 4 anemia (8/17), grade 3 or 4 central nervous system toxicity (19/14), and grade 3 or 4 peripheral neuropathy (1/12). Treatment may have contributed to the deaths of 6 patients treated with full doses of ifosfamide and cisplatin for 5 days. The proportion of patients responding to ifosfamide alone versus ifosfamide-cisplatin therapy was (0.36 versus 0.54) overall, 0.47 versus 0.61 for pelvic, 0.21 versus 0.54 for lung, and 0.33 versus 0.40 for "other" metastatic sites of measurable disease. The relative odds ratio of response adjusted for measurable sites of disease was 1.82 (P = 0.03, one-tailed test; 95% lower confidence limit, 1.06). Progression-free survival (PFS) and survival data suggest that the combination offers a slight prolongation of PFS (relative risk, 0.73; 95% upper confidence limit, 0.94; P = 0.02, one-tailed test), but no significant survival benefit (relative risk, 0.80, 95% upper confidence limit, 1.03; P = 0.071, one-tailed test). CONCLUSION: The addition of cisplatin to ifosfamide appears to offer a small improvement in progression-free survival over ifosfamide alone in the management of advanced carcinosarcoma of the uterus; the added toxicity may not justify the use of this combination.

Adult↗

PubMed2000

A bacterial genome in flux: the twelve linear and nine circular extrachromosomal DNAs in an infectious isolate of the Lyme disease spirochete Borrelia burgdorferi.

We have determined that Borrelia burgdorferi strain B31 MI carries 21 extrachromosomal DNA elements, the largest number known for any bacterium. Among these are 12 linear and nine circular plasmids, whose sequences total 610 694 bp. We report here the nucleotide sequence of three linear and seven circular plasmids (comprising 290 546 bp) in this infectious isolate. This completes the genome sequencing project for this organism; its genome size is 1 521 419 bp (plus about 2000 bp of undetermined telomeric sequences). Analysis of the sequence implies that there has been extensive and sometimes rather recent DNA rearrangement among a number of the linear plasmids. Many of these events appear to have been mediated by recombinational processes that formed duplications. These many regions of similarity are reflected in the fact that most plasmid genes are members of one of the genome's 161 paralogous gene families; 107 of these gene families, which vary in size from two to 41 members, contain at least one plasmid gene. These rearrangements appear to have contributed to a surprisingly large number of apparently non-functional pseudogenes, a very unusual feature for a prokaryotic genome. The presence of these damaged genes suggests that some of the plasmids may be in a period of rapid evolution. The sequence predicts 535 plasmid genes >/=300 bp in length that may be intact and 167 apparently mutationally damaged and/or unexpressed genes (pseudogenes). The large majority, over 90%, of genes on these plasmids have no convincing similarity to genes outside Borrelia, suggesting that they perform specialized functions.

Base Sequence↗

PubMed2000

Phase III randomized study of cisplatin versus paclitaxel versus cisplatin and paclitaxel in patients with suboptimal stage III or IV ovarian cancer: a gynecologic oncology group study.

PURPOSE: To assess progression-free survival (PFS) and overall survival (OS) in patients with suboptimally debulked epithelial ovarian cancer receiving cisplatin (100 mg/m(2)) or 24-hour infusion paclitaxel (200 mg/m(2)) or the combination of paclitaxel (135 mg/m(2)) followed by cisplatin (75 mg/m(2)). PATIENTS AND METHODS: After stratification for disease measurability, patients were randomized to receive six cycles of one of the treatments every 3 weeks. If measurable, complete response (CR) or partial response (PR) was determined. RESULTS: Six hundred fourteen of 648 patients who entered onto the trial were eligible. Monotherapies were discontinued more frequently (cisplatin because of toxicity or patient refusal [17%], and paclitaxel because of progression [20%]) compared with the combination therapy (7% and 6%, respectively). Neutropenia, fever, and alopecia were more severe with paclitaxel-containing regimens; whereas anemia, thrombocytopenia, neurotoxicity, nephrotoxicity, and gastrointestinal toxicity were more severe with cisplatin-containing regimens. The CR/PR rates on paclitaxel monotherapy were significantly lower compared with the cisplatin regimens (42% v 67%, respectively; P <.001). The relative hazard (RH) of first progression or death was significantly greater among those randomized to paclitaxel (RH = 1.41; 95% confidence interval [CI], 1.15 to 1.73; P <.001) when compared with cisplatin; however, RH did not differ significantly between the two cisplatin regimens (RH = 1.06; 95% CI, 0.895 to 1.30). Relative to cisplatin, the death rate on paclitaxel was 15% greater (RH = 1.15; 95% CI, 0. 929 to 1.42), and the death rate on the combination treatment was 1% less (RH = 0.99; 95% CI, 0.795 to 1.23). These differences among treatment groups were not statistically significant (P =.31). CONCLUSION: Cisplatin alone or in combination yielded superior response rates and PFS relative to paclitaxel. However, OS was similar in all three arms, and the combination therapy had a better toxicity profile. Therefore, the combination of cisplatin and paclitaxel remains the preferred initial treatment option.

Adult↗

PubMed1999

Phase II trial of paclitaxel in leiomyosarcoma of the uterus: a gynecologic oncology group study.

OBJECTIVE: The aim of this study was to determine the activity of paclitaxel in chemotherapy-naive patients with advanced or recurrent uterine leiomyosarcoma. METHODS: Patients received 175 mg/m(2) of paclitaxel iv over 3 h. Courses were repeated every 3 weeks until disease progression or adverse side effects supervened. RESULTS: Thirty-four women were entered, but 1 patient was ineligible because of wrong cell type. Median age was 55 years (range: 35-84 years). GOG performance status was 2 in 2 instances, 1 in 9 cases, and 0 in 22 others. Eight patients (23.4%) had received radiotherapy. A median of 2.5 courses was given (range: 1-18). Eleven patients (33.3%) experienced grade 3 or 4 neutropenia, 1 (2.9%) had grade 4 thrombocytopenia, and 1 had grade 3 anemia. There were no cases of grade 3 or 4 gastrointestinal or dermatologic toxicity. One patient each developed deep venous thrombosis and a grade 3 allergic reaction. Eight patients (24.2%) had stable disease for at least 2 courses of therapy. Three complete responses were reported (9.1%). CONCLUSION: With the dose and schedule tested, paclitaxel has limited activity in patients with uterine leiomyosarcoma. Modest toxicity suggests that a higher dose of paclitaxel might be evaluated.

Adult↗

PubMed1999

FIGO stage IIIC endometrial carcinoma with metastases confined to pelvic lymph nodes: analysis of treatment outcomes, prognostic variables, and failure patterns following adjuvant radiation therapy.

OBJECTIVES: This study was undertaken to evaluate the prognostic significance of isolated positive pelvic lymph nodes on survival and to analyze other prognostic variables, overall survival, and failure patterns in surgically staged endometrial carcinoma patients with positive pelvic lymph nodes and negative para-aortic lymph nodes following radiation therapy (RT). METHODS: Between January 1, 1987, and December 31, 1997, 782 women underwent primary treatment for uterine cancer at Indiana University Medical Center. Through a review of the medical records, we identified 58 patients with pathologic stage IIIA, 27 patients with pathologic stage IIIB, and 77 patients with pathologic stage IIIC endometrial carcinoma. Patients with pathologically positive or unsampled para-aortic lymph nodes and patients who received preoperative radiation therapy were excluded, leaving a study group of 17 patients with nodal metastases confined to pelvic lymph nodes. Thirteen patients received adjuvant pelvic RT using AP-PA or four-field technique. A median dose of 5040 cGy was delivered. Four patients received whole abdominal irradiation (WAI) delivering a median dose of 3000 cGy. Two patients received vaginal cuff boosts of 1000 and 3560 cGy to 0.5 cm from the vaginal surface mucosa via Cs-137 brachytherapy. Two patients also received adjuvant chemotherapy (cis-platinum and doxorubicin) and/or hormonal therapy (megestrol acetate). Disease-free and overall survivals were estimated using the Kaplan-Meier method of statistical analysis and prognostic variables were analyzed using the log-rank test. RESULTS: With a median follow-up of 51 months the actuarial 5-year disease-free survival was 81% and the actuarial 2-year and 5-year overall survival rates were 81 and 72%, respectively. Univariate analysis revealed that positive peritoneal cytology in conjunction with positive pelvic lymph nodes imparts a greater risk of recurrence and decreased overall survival. There were no pelvic and/or upper abdominal failures, but there were recurrences in the para-aortic lymph nodes (two patients) and distantly (two patients). CONCLUSION: Surgery followed by postoperative pelvic RT is a viable treatment option for pathologically staged stage IIIC endometrial carcinoma with disease confined to the pelvic lymph nodes. Failures in the para-aortic region suggest a possible role for extended-field RT. Patients with positive peritoneal cytology in conjunction with nodal metastasis fared poorly with pelvic RT. Studies evaluating the efficacy of WAI are ongoing. Finally, substages within FIGO stage IIIC are recommended in an effort to better understand and define treatment strategies which might be appropriate for these patients.

Actuarial Analysis↗

PubMed1999

Fyn tyrosine kinase reduces the ethanol inhibition of recombinant NR1/NR2A but not NR1/NR2B NMDA receptors expressed in HEK 293 cells.

NMDA receptors are potentiated by phosphorylation in a subunit- and kinase-specific manner. Both native and recombinant NMDA receptors are inhibited by behaviorally relevant concentrations of ethanol. Whether the phosphorylation state of individual subunits modulates the ethanol sensitivity of these receptors is not known. In this study, the effects of Fyn tyrosine kinase on the ethanol sensitivity of specific recombinant NMDA receptors expressed in HEK 293 cells were investigated. Whole-cell mode patch clamp and ratiometric calcium imaging demonstrated that the degree of ethanol inhibition of NR1/NR2B receptors was unaffected by Fyn tyrosine kinase. In contrast, the inhibition of NR1/NR2A receptors by ethanol (100 mM) was significantly reduced under conditions of enhanced Fyn-mediated tyrosine phosphorylation of the NR2A subunit. This effect was not observed at lower concentrations of ethanol (< or = 50 mM). These results suggest that tyrosine phosphorylation of specific NMDA receptors by Fyn tyrosine kinase may regulate the sensitivity of these receptors to the sedative/hypnotic concentrations of ethanol.

Cells, Cultured↗

PubMed1999

Effects of c-Src tyrosine kinase on ethanol sensitivity of recombinant NMDA receptors expressed in HEK 293 cells.

N-Methyl-D-aspartate (NMDA) receptors are ligand-gated ion channels that are important mediators of the actions of the excitatory amino acid neurotransmitter glutamate. Previous studies have shown that ethanol inhibits the function of both wild-type receptors found in neurons and recombinant NMDA receptors expressed in heterologous cells, such as oocytes and transfected mammalian cells. Although some studies have reported that certain subunit combinations display an enhanced sensitivity to ethanol, this effect is not observed in all experimental systems. This discrepancy may be due to varying levels of endogenous modulators, such as kinases, between different cell preparations. In this study, we investigated the effects of tyrosine phosphorylation on the ethanol sensitivity of NMDA receptor function using a recombinant cell system where levels of both NMDA subunits and protein kinases can be more carefully controlled. Human embryonic kidney (HEK 293) cells were transfected with different NMDA receptor subunits and a c-Src-green fluorescent protein (GFP) fusion protein that could be directly visualized in living cells. Agonist-stimulated calcium flux was measured in single cells using fura-2 video imaging. As expected, cells transfected with the NR1/NR2B subunits were more sensitive to inhibition by the NR2 selective antagonist ifenprodil than those transfected with NR1/ NR2A or NR1/NR2A/NR2B subunits. All receptor combinations were inhibited by ethanol (25 and 100 mM), with the NR1/NR2B combination being slightly more sensitive than NR1/NR2A or NR1/NR2A/NR2B. Control and NMDA-receptor transfected HEK 293 cells displayed a low degree of tyrosine phosphorylation as measured by immunofluorescence and Western immunoblotting using an antiphosphotyrosine antibody. Phosphorylation was markedly enhanced in cells transfected with the c-Src-GFP fusion protein. The sensitivity of NMDA receptors to either 25 or 100 mM ethanol, or 10 microM ifenprodil, was not significantly altered by co-transfection with c-Src-GFP. These results indicate that, although NMDA receptors can be a target of c-Src tyrosine kinase, tyrosine phosphorylation by this enzyme does not modulate the inhibitory effects of ethanol on NMDA-activated currents.

Animals↗

PubMed1999

Chronic ethanol upregulates NMDA and AMPA, but not kainate receptor subunit proteins in rat primary cortical cultures.

The present study examined the effects of chronic ethanol exposure on the expression of N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxalone (AMPA) and kainate receptor subunit proteins in rat cortical neuronal cultures grown in media containing 2 mM (high) or 0.1 mM (low) glutamine. Immunoblot analysis of NMDA (NR1, NR2A, NR2B, and NR2D), AMPA (GluR1 and GluR2/3), and kainate (GluR6/7) subunit polypeptides in 3-, 5-, 8-, 10-, and 12 day-old-cultures showed that NMDA receptor subunits NR1, NR2A, and NR2B and AMPA receptor subunits GluR2/3 progressively increased as a function of time, whereas levels of NMDA subunit NR2D were high at day 3 and progressively declined to barely detectable levels by day 12. Levels of AMPA subunit GluR1 and the kainate subunit GluR6/7 remained stable throughout the time course. Replacing the culture media with low glutamine media at culture day 5 did not alter the levels of subunit proteins measured at culture days 9 and 13. However, exposure of low glutamine cultures to 100 mM ethanol for 4 days (starting at culture day 9) significantly increased the levels of NMDA receptor subunits (NR1, NR2A, and NR2B) and AMPA receptor subunits (GluR1 and GluR2/3), but had no effect upon kainate receptor subunits (GluR6/7) or the synapse-associated proteins synapsin I and PSD-95. In contrast, chronic ethanol did not alter the levels of any of these subunit proteins in cells grown in high glutamine. These data demonstrate that under certain experimental conditions, prolonged exposure to ethanol upregulates NMDA and AMPA receptor subunit proteins, but has no effect upon kainate receptor subunit proteins. Because we have previously shown that acute ethanol can inhibit NMDA and AMPA, but not kainate, receptor function in these cultures, the increase in subunit expression likely reflects an adaptive response to the inhibitory effects of ethanol and suggests that both NMDA and AMPA receptors may play an important role in adaptation of the CNS to chronic ethanol.

Animals↗

PubMed1999

Detection of endometrial adenocarcinoma in two asymptomatic postmenopausal women receiving tamoxifen. A report of two cases.

BACKGROUND: Tamoxifen has been linked to an increased risk for the development of endometrial adenocarcinoma. The majority of these carcinomas present with postmenopausal bleeding. The current standard is to undertake sampling only after the onset of bleeding. CASES: Two cases illustrate the utility of transvaginal saline infusion sonohysterography (TVS/SIS) in the detection of endometrial carcinoma prior to the onset of bleeding. CONCLUSION: Annual TVS/SIS may be useful for screening asymptomatic, tamoxifen-exposed patients with a uterus in situ and is likely to be more acceptable to such patients than annual biopsies.

Adenocarcinoma↗

PubMed1998

Guanylyltransferase and RNA 5'-triphosphatase activities of the purified expressed VP4 protein of bluetongue virus.

We have examined the RNA-capping enzyme activities of bluetongue virus (BTV) minor core protein, VP4. Recombinant BTV VP4 protein was purified to homogeneity from insect cell culture infected with a baculovirus VP4 of BTV serotype 10. We demonstrate that the purified protein, and VP4 encapsidated in core-like particles, react with GTP and covalently bind GMP via a phosphoamide linkage, a characteristic feature of guanylyltransferase enzyme. VP4 also catalyses a GTP-PPi exchange reaction indicating that the protein is the guanylyltransferase of the virus. In addition, VP4 possesses an RNA 5'-triphosphatase activity which catalyses the first step in the RNA-capping sequence. Further, an inorganic pyrophosphatase activity was identified which may aid the transcription activity within the virus by removing inorganic pyrophosphate which is an inhibitor of the polymerization reaction. Finally, the direct evidence of VP4 capping activity has been obtained by demonstrating in vitro transfer of GMP to the 5' end of in vitro synthesized BTV ssRNA transcripts to form a cap structure.

Acid Anhydride Hydrolases↗