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Biomedical subjects

S E Jones

Publications and source records attributed to S E Jones.

At least 55 records · Page 3Linked to original sources

Exemestane is superior to megestrol acetate after tamoxifen failure in postmenopausal women with advanced breast cancer: results of a phase III randomized double-blind trial. The Exemestane Study Group.

PURPOSE: This phase III, double-blind, randomized, multicenter study evaluated the efficacy, pharmacodynamics, and safety of the oral aromatase inactivator exemestane (EXE) versus megestrol acetate (MA) in postmenopausal women with progressive advanced breast cancer who experienced failure of tamoxifen. PATIENTS AND METHODS: A total of 769 patients were randomized to EXE 25 mg/d (n = 366) or MA (n = 403) 40 mg four times daily. Tumor response, duration of tumor control, tumor-related signs and symptoms (TRSS), quality of life (QOL), survival, and tolerability were evaluated. RESULTS: Overall objective response (OR) rates were higher in patients treated with EXE than in those treated with MA (15.0% v 12.4%); a similar trend was noted in patients with visceral metastases (13.5% v 10.5%). Median survival time was significantly longer with EXE (median not reached) than with MA (123.4 weeks; P =.039), as were the median duration of overall success (OR or stable disease > or = 24 weeks; 60.1 v 49.1 weeks; P =.025), time to tumor progression (20.3 v 16.6 weeks; P =.037), and time to treatment failure (16.3 v 15.7 weeks; P =.042). Compared with MA, there were similar or greater improvements in pain, TRSS, and QOL with EXE. Both drugs were well tolerated. Grade 3 or 4 weight changes were more common with MA (17.1% v 7.6%; P =.001). CONCLUSION: EXE prolongs survival time, time to tumor progression, and time to treatment failure compared with MA and offers a well-tolerated treatment option for postmenopausal women with progressive advanced breast cancer who experienced failure of tamoxifen.

Administration, Oral↗

Exemestane: a novel aromatase inactivator for breast cancer.

Exemestane is a unique inactivator of the aromatase enzyme and differs from the two approved aromatase inhibitors. It is well absorbed at a daily oral dose of 25 mg and produces significant suppression of aromatase and plasma estrogen levels without androgenic side effects. Toxicity is mild with menopausal symptoms predominating. Exemestane is approved for the treatment of postmenopausal women with recurrent breast cancer. In reported clinical trials, exemestane was effective in patients failing tamoxifen, megestrol acetate, or even other aromatase inhibitors in phase II trials and was superior to megestrol acetate in a phase III randomized trial in which an early survival advantage for exemestane was observed. Studies evaluating first-line exemestane for adjuvant use and as a chemopreventive agent are underway.

Androstadienes↗

Exemestane improves survival in metastatic breast cancer: results of a phase III randomized study.

We compared the efficacy and safety of the oral aromatase inactivator exemestane (EXE) with megestrol acetate (MA) in women with metastatic breast cancer. This phase III randomized, double-blind, multicenter study was conducted in 769 postmenopausal women who had experienced tamoxifen failure. Treatment arms consisted of EXE 25 mg once daily (n=366) or MA 40 mg four times daily (160 mg daily; n=403). Peer-reviewed, intent-to-treat analyses demonstrated that EXE induced a trend toward higher rates of complete response (CR)+partial response (PR) (15.0% vs. 12.4%) and of CR+PR+stable disease (SD)=24 weeks (37.4% vs. 34.6%), but differences were not statistically significant. Statistically significant differences favoring EXE were seen in median duration of CR+PR+SD=24 weeks (60.1 vs. 49.1 weeks; P=0.025), time to tumor progression (20.3 vs. 16.6 weeks; P=0.037), time to treatment failure (16.3 vs. 15.7 weeks; P=0.042), and overall survival (not reached vs. 123.4 weeks; P=0.039). Both treatments were well tolerated, but MA was associated with more grade 3 or 4 weight gain (8% vs. 17%, P=0.001); the pain score was sim-ilar in both groups. There was a trend toward superiority in treatment-related signs and symptoms (TRSS) with EXE. There was greater improvement in the pain score and TRSS in patients achieving an objective response with EXE vs. MA. Quality of life improved or was similar for EXE in most domains. Exemestane offers an important new treatment option for postmenopausal women with hormone-responsive breast cancer.

Administration, Oral↗

Altered expression of secreted frizzled-related protein-2 in retinitis pigmentosa retinas.

PURPOSE: Inherited retinal degenerations such as retinitis pigmentosa (RP) are characterized by progressive death of the photoreceptors due to apoptosis. To identify changes in gene expression associated with the degenerative state in RP retinas, expression profiling of apoptosis-related genes was performed using a gridded array technique. METHODS: Total RNAs from RP and control retinas were used to generate radiolabeled cDNA probes to screen gridded membrane arrays of 205 apoptosis-related genes. Reverse transcription-polymerase chain reaction was used to generate probes corresponding to differentially expressed genes for Northern blot analysis and for mRNA in situ hybridization studies of retinal cryosections. Fluorescence immunocytochemistry was performed on retinal sections using available antibodies. RESULTS: By expression profiling, we identified upregulated expression of the mRNA for secreted Frizzled-related protein-2 (SFRP2) in RP retina in comparison with control. By Northern blot analysis, SFRP2 mRNA levels were 2- to 20-fold higher in RP samples than in controls. The localization of SFRP2 mRNA by in situ hybridization varied according to the degree of degeneration, from stratified in relatively well-preserved retinas to diffuse in the highly degenerative state. By immunofluorescence, SFRP2 protein in RP retinas was found mainly to colocalize with the cell adhesion and signal transducing protein beta-catenin. CONCLUSIONS: SFRPs can regulate apoptosis in vitro and appear to interact with the Wnt/Frizzled signaling pathway, which includes routes to apoptotic activation. Increased SFRP2 expression in RP retinas suggests that an altered pattern of Wnt signal transduction may be a step in the degenerative process linking causal mutations with eventual photoreceptor demise.

Aged↗

Inhibition of cardiac inward-rectifier K+ current by terodiline.

The antispasmodic agent terodiline has cardiotoxic effects that include QT lengthening. To determine whether inhibition of inwardly-rectifying K+ current (I(K1)) might be a factor in the cardiotoxicity, we measured I(K1) in guinea pig ventricular myocytes. Terodiline reduced outward I(K1) with an IC50 of 7 microM; maximal reduction was 60% with 100-300 microM concentration. Inhibition was independent of current direction, and persisted after removal of the drug. Terodiline (3-5 microM) lengthened action potentials in guinea pig papillary muscles by ca. 10%, primarily by slowing phase 3 repolarization; higher concentrations abbreviated the plateau and markedly slowed late repolarization. Terodiline washout provoked an extra lengthening, consistent with persistent inhibition of I(K1) and rapid recovery of net inward plateau current. The results suggest that inhibition of I(K1) is a likely factor in the cardiotoxicity of the drug.

Action Potentials↗

Exaggerated cardiovascular response to anaesthesia--a case for investigation.

We present a case of a 40-year-old woman who developed major cardiovascular complications during anaesthesia for an elective clipping of a cerebral arteriovenous malformation. Postoperative investigation confirmed the diagnosis of an adrenal phaeochromocytoma. In retrospect, it became apparent that she had experienced a series of potentially life-threatening events over a 20-year period all of which are known complications of phaeochromocytoma. This case highlights the importance of investigating young patients who have unexpected and unexplained cardiovascular events during anaesthesia and surgery.

Adrenal Gland Neoplasms↗

Lack of causal relationship between clusterin expression and photoreceptor apoptosis in light-induced retinal degeneration.

Induction of apoptosis in the retina leads to cellular death by molecular mechanisms that are not well understood. Clusterin expression is increased in tissues undergoing apoptosis, including retinal neurodegenerative states, but the causal relationships remain to be clarified. To gain insight into clusterin's role in photoreceptor apoptosis, the cellular distribution of clusterin mRNA was compared with the pattern of apoptotic nuclear labelling in a rat model of light-induced retinal degeneration. In control retinal sections, clusterin mRNA was localized to the retinal pigment epithelium cells, photoreceptor inner segments, inner nuclear layer, and ganglion cell layer. Clusterin expression decreased in photoreceptors and retinal pigment epithelium cells, which progressively degenerated, and increased in preserved inner nuclear layer, in proportion to the duration of light exposure in both cyclic light- and dark-reared animals. These results suggest that clusterin is not causally involved in apoptotic mechanisms of photoreceptor death, but may relate to cytoprotective functions.

Animals↗

Initial experience of intramammary prostheses in breast conservation surgery.

AIMS: We assessed the cosmetic and psychological effects of prosthetic intramammary breast reconstruction on women undergoing complete local excision for breast cancer. METHODS: Twenty-two women (mean age 54) underwent insertion of a Nagor silicone prosthesis into the breast cavity immediately following complete local excision. Following surgery, patients were assessed (range: 6 weeks to 1 year) by a postal questionnaire and independent photographs. RESULTS: Eighteen out of twenty-two (81.8%) women completed and returned the questionnaire, and 14 out of 22 (63.6%) women were photographed. Thirteen out of eighteen (72.2%) women were either satisfied or very satisfied with the prosthesis, and 10 had experienced no problems since surgery. From the group of patients who were either satisfied or very satisfied, the total photograph assessment score was 135 out of a possible maximum score of 165. Five patients (27.8%) were very dissatisfied and requested removal of the prosthesis. CONCLUSIONS: When performing a complete local excision for carcinoma of the breast, insertion of an intracavity prosthesis should be considered when this would significantly improve the cosmetic outcome.

Breast Implantation↗

Randomized, double-blind, placebo-controlled trial to evaluate the hematopoietic growth factor PIXY321 after moderate-dose fluorouracil, doxorubicin, and cyclophosphamide in stage II and III breast cancer.

PURPOSE: To measure the effect of PIXY321 (granulocyte-macrophage colony-stimulating factor/interleukin-3 S. cerevisiae fusion protein) on the incidence, duration, and complications of neutropenia and thrombocytopenia after moderate-dose fluorouracil 600 mg/m(2), doxorubicin 60 mg/m(2), and cyclophosphamide 750 mg/m(2) (FAC) chemotherapy in patients with stage II and III breast cancer. PATIENTS AND METHODS: In this multicenter, randomized, double-blind placebo-controlled trial, 71 women were to receive four 21-day cycles of treatment with moderate-dose FAC chemotherapy by short intravenous infusion on day 1, followed by either placebo or PIXY321 (375 microg/m(2) subcutaneously twice a day) on days 3 to 15. All patients were to receive prophylactic oral ciprofloxacin when the absolute neutrophil count was less than 1,000/microL. RESULTS: PIXY321 significantly reduced the incidence and duration of grade 3 and grade 4 neutropenia in cycles 1 and 2 and the duration of grade 3 neutropenia in cycles 1 through 4. In cycles 3 and 4, grade 3 thrombocytopenia was significantly more common with PIXY321 (P <.05). Two patients, both in the PIXY321 group, required platelet transfusions. Fever and hospitalization for intravenous antibiotics were significantly more common in the PIXY321 group during cycle 1 only. More patients in the PIXY321 group achieved hematologic recovery by day 22 in cycles 1 through 3, and time to recovery was significantly shorter with PIXY321 in all cycles. FAC dose intensity was roughly 2% higher in the PIXY321 group (P = NS). Nonhematologic events of any intensity occurring with significantly greater overall frequency in the PIXY321 group included injection-site reactions, fever, chills, abdominal pain, and arthralgia. No patient died on study or within 30 days of her last dose of study drug. CONCLUSION: PIXY321 decreased the incidence and duration of FAC-induced grade 3 and 4 neutropenia in cycles 1 and 2 and significantly shortened the time to hematologic recovery in all cycles. However, it produced more systemic toxicity as well as thrombocytopenia in cycles 3 and 4.

Adenocarcinoma↗

Multicenter phase II study of capecitabine in paclitaxel-refractory metastatic breast cancer.

PURPOSE: Capecitabine is a novel, oral, selectively tumor-activated fluoropyrimidine carbamate. This large multicenter phase II trial tested the efficacy and safety of twice-daily oral capecitabine at 2,510 mg/m2/d given for 2 weeks followed by a 1-week rest period and repeated in 3-week cycles, in patients with paclitaxel-refractory metastatic breast cancer. PATIENTS AND METHODS: Patients were to have received at least two but not more than three prior chemotherapeutic regimens, one of which had to have contained paclitaxel given for metastatic disease. One hundred sixty-three patients were entered onto the study at 25 centers, and 162 patients received capecitabine. One hundred thirty-five patients had bidimensionally measurable disease, and 27 patients had assessable disease. RESULTS: The overall response rate was 20% (95% confidence interval, 14% to 28%). All responding patients were resistant to or had failed paclitaxel, and all had received an anthracycline. Three complete responses were seen, with complete response durations of 106, 109, and 194+ days. Median duration of response was 8.1 months, median survival time was 12.8 months, and the median time to disease progression was 93 days. The most common treatment-related adverse events were hand-foot syndrome, diarrhea, nausea, vomiting, and fatigue. Diarrhea (14%) and hand-foot syndrome (10%) were the only treatment-related adverse events that occurred with grade 3 or 4 intensity in more than 10% of patients. CONCLUSION: Capecitabine is an active drug in the treatment of paclitaxel-refractory metastatic breast cancer. It has a favorable toxicity profile with the added advantage of being an oral drug administered at home.

Adult↗

Effect of targeted expression of clusterin in photoreceptor cells on retinal development and differentiation.

Clusterin expression is increased in tissues undergoing apoptosis, including neurodegenerative retina, but the causal relationships remain to be clarified. To test the hypothesis that overexpression of clusterin could induce apoptosis in neurons, transgenic mice were generated in which rat clusterin transgene was expressed in photoreceptor cells under the transcriptional control of the human interphotoreceptor retinoid-binding protein (IRBP) promoter. Photoreceptor cell death in the resulting transgenic mice was examined by histology and TUNEL techniques. The expression of the clusterin transgene was confirmed by in situ hybridization in the photoreceptor cells, and results in a complex pattern of clusterin protein distribution in the retina. A reduction in apoptotic staining in the transgenic retinas was observed from birth to postnatal day 15. These results suggest that clusterin is not causally involved in apoptotic mechanisms of photoreceptor cell death, but may relate to cytoprotective functions.

Age Factors↗

Expression patterns of neurturin and its receptor components in developing and degenerative mouse retina.

PURPOSE: Neurturin (NTN) and its receptor components (GFRalpha2 and Ret) play an important role in the survival of different populations of neurons in the central and peripheral nervous systems. To gain insight into their possible functions throughout normal retinal development and during retinal neuronal apoptosis, the retinal distribution of expression of NTN and GFRalpha2 mRNAs and Ret protein were compared in control and retinal degeneration (rd) mice. METHODS: Eyes from control and rd animals were fixed in paraformaldehyde before sectioning. For in situ hybridization, retinal sections were hybridized with 35S-radiolabeled sense and antisense riboprobes for murine NTN and GFRalpha2 and were autoradiographed. Ret localization was detected by immunofluorescence. RESULTS: Neurturin mRNA expression was modulated through normal postnatal retinal development and was localized primarily to the inner retina and photoreceptor outer segments. GFRalpha2 mRNA displayed a diffuse developmental pattern of expression, but in the mature normal retina, NTN and GFRalpha2 mRNAs were more closely colocalized. Ret protein was localized particularly at the outer segments of photoreceptors, inner retina, and ganglion cell layers, but there were no prominent differences among genotypes. Increased NTN mRNA expression was detected in the retinal pigment epithelium and neural retina in concert with photoreceptor degeneration in rd mouse. In contrast, the level of GFRalpha2 mRNA was lower in rd compared with that in normal retina. CONCLUSIONS: These results suggest that NTN and its receptor are involved in retinal postnatal development and maintenance and that alterations in their transcription patterns are associated with inherited retinal degeneration.

Animals↗

Action potentials, contraction, and membrane currents in guinea pig ventricular preparations treated with the antispasmodic agent terodiline.

Terodiline was widely prescribed for urinary incontinence before reports of adverse cardiac effects that included bradycardia, QT lengthening, and ventricular tachyarrhythmia. The present study on guinea pig papillary muscles and ventricular myocytes was undertaken to gain insight into the cardioactive properties of the drug. Clinically relevant concentrations (<10 microM) of terodiline lengthened the action potential duration by up to 12%; higher concentrations shortened the duration in a concentration-dependent manner. The drug depressed maximal upstroke velocity in a use-dependent manner; the IC(50) value was near 150 microM in muscles driven at 1 Hz, 60 microM at 3 Hz, 38 microM at 5 Hz, and 3 microM at 1 Hz in muscles depolarized with 14 mM K(+). Submicromolar terodiline frequently had a small positive inotropic effect, whereas micromolar concentrations depressed force in a frequency-dependent manner. Voltage-clamp results on myocytes indicate that terodiline inhibits three membrane currents that govern repolarization: 1) E4031-sensitive, rapidly activating K(+) current with an IC(50) value near 0.7 microM as previously reported; 2) slowly activating, delayed-rectifier K(+) current with an IC(50) value of 26 microM; and 3) L-type Ca(2+) current with an IC(50) value of 12 microM. These findings are correlated with the changes in action potential configuration and developed tension and discussed in relation to the cardiotoxic effects of the drug.

Action Potentials↗

Retinal expression of gamma-crystallins in the mouse.

PURPOSE: High levels of expression of a form of gamma-crystallin mRNA in mouse retina have been identified. Because the six murine gamma-crystallins have generally been regarded as specific to the lens, the expression of these crystallins at the mRNA and protein levels in the retina were evaluated in more detail. METHODS: Expression of gammaE/F-crystallin mRNA was examined by northern blot analysis and reverse transcription-polymerase chain reaction (RT-PCR) analysis applied to murine retinal and lens total RNAs. For gammaA-D-crystallin mRNAs, a multiplex RT-PCR was used on total cDNAs. The detection of total gamma-crystallin protein in the retina was performed using an antibody to bovine lens gamma-crystallins, applied to protein extracts in immunoblot analysis and to cryostat sections of ocular tissues in immunofluorescence studies. RESULTS: By RT-PCR, we confirmed expression of both gammaE-and gammaF-crystallin as well as all four (gammaA-gammaD) remaining crystallins at the mRNA level in the mouse retina. Gamma-crystallin proteins were also detectable in murine retina by immunoblot analysis, although at a lower level than in the lens. By immunocytochemistry, gamma-crystallins were localized particularly to the inner retina, outer plexiform layer, and the photoreceptors during postnatal development. CONCLUSIONS: Our findings of gamma-crystallin mRNA and protein expression in the retina indicate that none of the major crystallin classes is uniquely expressed in the lens. The expression of gamma-crystallins in the developing murine retina suggests a role analogous to the anti-stress properties established for the small heat-shock protein alphaB-crystallin, perhaps in response to varying exposure to light.

Animals↗

Alpha-difluoromethylornithine as treatment for metastatic breast cancer patients.

DFMO (alpha-difluoromethylornithine) is an oral irreversible inhibitor of ornithine decarboxylase, the first rate-limiting enzyme in polyamine synthesis. DFMO has been shown to have antiproliferative effects against several human cancers, and some studies have suggested that DFMO may have pro-apoptotic and anti-invasive properties as well. DFMO is well tolerated with minimal toxicity but has been associated with ototoxicity with prolonged daily administration. We conducted a Phase I/II tolerability, pharmacokinetic, and efficacy study of high-dose DFMO in metastatic breast cancer patients. Twenty-one patients were treated with 4800 mg of DFMO p.o. three times a day for 14 days, followed by a 2-week drug holiday on a 28-day cycle. Urinary polyamine and blood DFMO levels were measured at multiple time points during therapy. High-dose DFMO was well tolerated, and no clinically significant ototoxicity was noted. No patient achieved an objective antitumor response; however, one patient with heavily pretreated liver metastases has achieved stable disease for 18 months to date on DFMO. Putrescine, spermine, and spermidine urinary levels were suppressed with DFMO treatment and remained low during the 2-week drug holiday. High-dose DFMO on a schedule of 2 weeks on treatment followed by 2 weeks off is well tolerated, is not associated with ototoxicity, and leads to sustained suppression of urinary polyamine levels. Although not an active cytotoxic agent for metastatic breast cancer, the intriguing prolonged growth arrest of liver metastases in one patient highlights the potential clinical growth inhibitory properties of DFMO. We believe that DFMO is worthy of study as adjuvant therapy in primary breast cancer patients and as a chemopreventive agent.

Adult↗

The theory and practice of internal 'tunnel' restorations: a review of the literature and observations on clinical performance over eight years in practice.

The tunnel or 'internal' restoration to restore an approximal caries lesion was first described in 1984. The technique allows the operator to conserve the important external anatomical features of the tooth, thereby saving considerable clinical time while leaving relatively little of the material externalized. The development of a new generation of glass-ionomer materials with higher flexural and compressive strengths appears to satisfy the main objective of carious dentine replacement facilitated by a 'keyhole' internal preparation. The long-term clinical evaluation of these materials is difficult since new formulations are being continually developed. The literature was reviewed. Clinical cases restoring approximal caries lesions in permanent molars and premolars were observed in a private practice. Over the course of eight years 60 tunnel restorations were placed in 48 regularly attending patients. The materials used in both total and partial tunnel restorations were Ketac Silver, Hi-Dense and Fuji IX. At eight years a failure rate of 15% was seen in the 50 restorations observed at last dental examination. The findings suggest that modern tunnel techniques may offer a restorative technique worthy of consideration in treating primary approximal caries lesions.

Adolescent↗