CREB: a Ca(2+)-regulated transcription factor phosphorylated by calmodulin-dependent kinases

The mechanism by which Ca2+ mediates gene induction in response to membrane depolarization was investigated. The adenosine 3',5'-monophosphate (cAMP) response element-binding protein (CREB) was shown to function as a Ca(2+)-regulated transcription factor and as a substrate for depolarization-activated Ca(2+)-calmodulin-dependent protein kinases (CaM kinases) I and II. CREB residue Ser133 was the major site of phosphorylation by the CaM kinases in vitro and of phosphorylation after membrane depolarization in vivo. Mutation of Ser133 impaired the ability of CREB to respond to Ca2+. These results suggest that CaM kinases may transduce electrical signals to the nucleus and that CREB functions to integrate Ca2+ and cAMP signals.

Antiretroviral therapy in adults: updated recommendations of the International AIDS Society-USA Panel

OBJECTIVE

To update recommendations for antiretroviral therapy for adult human immunodeficiency virus type 1 (HIV-1) infection, based on new information and drugs that are available.

PARTICIPANTS

A 17-member international physician panel with antiretroviral research and HIV patient care experience initially convened by the International AIDS Society-USA in December 1995.

EVIDENCE

Available clinical and basic science data including phase 3 controlled trials; data on clinical, virologic, and immunologic end points; research conference reports; HIV pathogenesis data; and panel expert opinion. Recommendations were limited to therapies available (US Food and Drug Administration approved) in 1999.

CONSENSUS PROCESS

The panel assesses new research reports and interim results and regularly meets to consider how the new data affect therapy recommendations. Recommendations are updated via full-panel consensus. Guidelines are presented as recommendations if the supporting evidence warrants routine use in the particular situation and as considerations if data are preliminary or incomplete but suggestive.

CONCLUSIONS

The availability of new antiretroviral drugs has expanded treatment choices. The importance of adherence, emerging long-term complications of therapy, recognition and management of antiretroviral failure, and new monitoring tools are addressed. Optimal care requires individualized management and ongoing attention to relevant scientific and clinical information in the field.

Regulation of CREB phosphorylation in the suprachiasmatic nucleus by light and a circadian clock

Mammalian circadian rhythms are regulated by a pacemaker within the suprachiasmatic nuclei (SCN) of the hypothalamus. The molecular mechanisms controlling the synchronization of the circadian pacemaker are unknown; however, immediate early gene (IEG) expression in the SCN is tightly correlated with entrainment of SCN-regulated rhythms. Antibodies were isolated that recognize the activated, phosphorylated form of the transcription factor cyclic adenosine monophosphate response element binding protein (CREB). Within minutes after exposure of hamsters to light, CREB in the SCN became phosphorylated on the transcriptional regulatory site, Ser133. CREB phosphorylation was dependent on circadian time: CREB became phosphorylated only at times during the circadian cycle when light induced IEG expression and caused phase shifts of circadian rhythms. These results implicate CREB in neuronal signaling in the hypothalamus and suggest that circadian clock gating of light-regulated molecular responses in the SCN occurs upstream of phosphorylation of CREB.

Antiretroviral therapy for HIV infection in 1998: updated recommendations of the International AIDS Society-USA Panel

OBJECTIVE

To provide recommendations for antiretroviral therapy based on information available in mid-1998.

PARTICIPANTS

An international panel of physicians with expertise in antiretroviral research and care of patients with human immunodeficiency virus (HIV) infection, first convened by the International AIDS Society-USA in December 1995.

EVIDENCE

The panel reviewed available clinical and basic science study results (including phase 3 controlled trials; clinical, virologic, and immunologic end point data; data presented at research conferences; and studies of HIV pathophysiology); opinions of panel members were also considered. Recommendations were limited to drugs available in mid-1998.

CONSENSUS PROCESS

Panel members monitor new clinical research reports and interim results. The full panel meets regularly to discuss how the new information may change treatment recommendations. Updated recommendations are developed through consensus of the entire panel at each stage of development.

CONCLUSIONS

Accumulating data from clinical and pathogenesis studies continue to support early institution of potent antiretroviral therapy in patients with HIV infection. A variety of combination regimens show potency, expanding choices for initial regimens for individual patients. Plasma HIV RNA assays with increased sensitivity are important in monitoring therapeutic response; however, more data are needed to determine precisely the HIV RNA levels that define treatment failure. Long-term adverse drug effects are beginning to emerge, requiring ongoing attention. Some issues regarding optimal long-term approaches to antiretroviral management are unresolved. The increased complexity in HIV management requires ongoing monitoring of new data for optimal treatment of HIV infection.

The cloche and spadetail genes differentially affect hematopoiesis and vasculogenesis

In vertebrates, hematopoietic and vascular progenitors develop from ventral mesoderm. The first primitive wave of hematopoiesis yields embryonic red blood cells, whereas progenitor cells of subsequent definitive waves form all hematopoietic cell lineages. In this report we examine the development of hematopoietic and vasculogenic cells in normal zebrafish and characterize defects in cloche and spadetail mutant embryos. The zebrafish homologs of lmo2, c-myb, fli1, flk1, and flt4 have been cloned and characterized in this study. Expression of these genes identifies embryonic regions that contain hematopoietic and vascular progenitor cells. The expression of c-myb also identifies definitive hematopoietic cells in the ventral wall of the dorsal aorta. Analysis of b316 mutant embryos that carry a deletion of the c-myb gene demonstrates that c-myb is not required for primitive erythropoiesis in zebrafish even though it is expressed in these cells. Both cloche and spadetail mutant embryos have defects in primitive hematopoiesis and definitive hematopoiesis. The cloche mutants also have significant decreases in vascular gene expression, whereas spadetail mutants expressed normal levels of these genes. These studies demonstrate that the molecular mechanisms that regulate hematopoiesis and vasculogenesis have been conserved throughout vertebrate evolution and the clo and spt genes are key regulators of these programs.

A randomized study of antiretroviral management based on plasma genotypic antiretroviral resistance testing in patients failing therapy. CPCRA 046 Study Team for the Terry Beirn Community Programs for Clinical Research on AIDS

OBJECTIVE

To determine the short-term effects of using genotypic antiretroviral resistance testing (GART) with expert advice in the management of patients failing on a protease inhibitor and two nucleoside reverse transcriptase inhibitors.

DESIGN

Prospective randomized controlled trial.

SETTING

Multicenter community-based clinical trials network.

PATIENTS

One-hundred and fifty-three HIV-infected adults with a threefold or greater rise in plasma HIV-1 RNA on at least 16 weeks of combination antiretroviral therapy.

INTERVENTIONS

Randomization was either to a GART group, where genotype interpretation and suggested regimens were provided to clinicians, or to a no-GART group, where treatment choices were made without such input.

MAIN OUTCOMES MEASURES

Plasma HIV-1 RNA levels and CD4 cell counts were measured at 4, 8, and 12 weeks following randomization. The primary endpoint was change in HIV-1 RNA levels from baseline to the average of the 4 and 8 week levels.

RESULTS

The average baseline CD4 cell count was 230 x 10(6) cells/l and the median HIV-1 RNA was 28,085 copies/ml. At entry, 82 patients were failing on regimens containing indinavir, 51 on nelfinavir, 11 on ritonavir, and nine on saquinavir. HIV-1 RNA, averaged at 4 and 8 weeks, decreased by 1.19 log10 for the 78 GART patients and -0.61 log10 for the 75 no-GART patients (treatment difference: -0.53 log, 95% confidence interval, -0.77 to -0.29; P = 0.00001). Overall, the best virologic responses occurred in patients who received three or more drugs to which their HIV-1 appeared to be susceptible.

CONCLUSION

In patients failing triple drug therapy, GART with expert advice was superior to no-GART as measured by short-term viral load responses.

Development and validation of a new body-image assessment scale

This investigation reports the development and validation of a new and improved body-image assessment tool, the Contour Drawing Rating Scale, consisting of nine male and nine female contour drawings. The drawings were designed with detailed features, are of precisely graduated sizes, and are easily split at the waist for accurate upper and lower body comparisons. Initial evidence of the scale's reliability and validity supports its use as a measure of body-size perception.

A randomized trial comparing primary angioplasty with a strategy of short-acting thrombolysis and immediate planned rescue angioplasty in acute myocardial infarction: the PACT trial. PACT investigators. Plasminogen-activator Angioplasty Compatibility Trial

OBJECTIVES

The study evaluated the efficacy and safety of a short-acting reduced-dose fibrinolytic regimen to promote early infarct-related artery (IRA) patency during the inherent delay experienced by infarct patients referred for angioplasty as the principal recanalization modality.

BACKGROUND

Previous approaches using long-acting, full-dose thrombolytic infusions rarely showed benefit, but they did increase adverse event rates.

METHODS

Following aspirin and heparin, 606 patients were randomized to a 50-mg bolus of recombinant tissue-type plasminogen activator (rt-PA) (alpha half-life 4.5 min) or to placebo followed by immediate angiography with angioplasty if needed. The end points included patency rates on catheterization laboratory (cath lab) arrival, technical results when PTCA (percutaneous transluminal coronary angioplasty) was performed, complication rates, and left ventricular (LV) function by treatment assignment and time to restored patency following angioplasty.

RESULTS

Patency on cath lab arrival was 61% with rt-PA (28% Thrombolysis in Myocardial Infarction trial [TIMI]-2, 33% TIMI-3), and 34% with placebo (19% TIMI-2, 15% TIMI-3) (p = 0.001). Rescue and primary PTCA restored TIMI-3 in closed arteries equally (77%, 79%). No differences were observed in stroke or major bleeding. Left ventricular function was similar in both treatment groups, but convalescent ejection fraction (EF) was highest with a patent IRA (TIMI-3) on cath lab arrival (62.4%) or when produced by angioplasty within an hour of bolus (62.5%). However, in 88% of angioplasties, the delay exceeded 1 h: convalescent EF 57.3%.

CONCLUSIONS

Tailored thrombolytic regimens compatible with subsequent interventions lead to more frequent early recanalization (before cath arrival), which facilitates greater LV function preservation with no augmentation of adverse events.

Association of clinical factors and recent anticancer therapy with COVID-19 severity among patients with cancer: a report from the COVID-19 and Cancer Consortium

BACKGROUND

Patients with cancer may be at high risk of adverse outcomes from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We analyzed a cohort of patients with cancer and coronavirus 2019 (COVID-19) reported to the COVID-19 and Cancer Consortium (CCC19) to identify prognostic clinical factors, including laboratory measurements and anticancer therapies.

PATIENTS AND METHODS

Patients with active or historical cancer and a laboratory-confirmed SARS-CoV-2 diagnosis recorded between 17 March and 18 November 2020 were included. The primary outcome was COVID-19 severity measured on an ordinal scale (uncomplicated, hospitalized, admitted to intensive care unit, mechanically ventilated, died within 30 days). Multivariable regression models included demographics, cancer status, anticancer therapy and timing, COVID-19-directed therapies, and laboratory measurements (among hospitalized patients).

RESULTS

A total of 4966 patients were included (median age 66 years, 51% female, 50% non-Hispanic white); 2872 (58%) were hospitalized and 695 (14%) died; 61% had cancer that was present, diagnosed, or treated within the year prior to COVID-19 diagnosis. Older age, male sex, obesity, cardiovascular and pulmonary comorbidities, renal disease, diabetes mellitus, non-Hispanic black race, Hispanic ethnicity, worse Eastern Cooperative Oncology Group performance status, recent cytotoxic chemotherapy, and hematologic malignancy were associated with higher COVID-19 severity. Among hospitalized patients, low or high absolute lymphocyte count; high absolute neutrophil count; low platelet count; abnormal creatinine; troponin; lactate dehydrogenase; and C-reactive protein were associated with higher COVID-19 severity. Patients diagnosed early in the COVID-19 pandemic (January-April 2020) had worse outcomes than those diagnosed later. Specific anticancer therapies (e.g. R-CHOP, platinum combined with etoposide, and DNA methyltransferase inhibitors) were associated with high 30-day all-cause mortality.

CONCLUSIONS

Clinical factors (e.g. older age, hematological malignancy, recent chemotherapy) and laboratory measurements were associated with poor outcomes among patients with cancer and COVID-19. Although further studies are needed, caution may be required in utilizing particular anticancer therapies.

CLINICAL TRIAL IDENTIFIER

NCT04354701.

Rec8p, a meiotic recombination and sister chromatid cohesion phosphoprotein of the Rad21p family conserved from fission yeast to humans

Our work and that of others defined mitosis-specific (Rad21 subfamily) and meiosis-specific (Rec8 subfamily) proteins involved in sister chromatid cohesion in several eukaryotes, including humans. Mutation of the fission yeast Schizosaccharomyces pombe rec8 gene was previously shown to confer a number of meiotic phenotypes, including strong reduction of recombination frequencies in the central region of chromosome III, absence of linear element polymerization, reduced pairing of homologous chromosomes, reduced sister chromatid cohesion, aberrant chromosome segregation, defects in spore formation, and reduced spore viability. Here we extend the description of recombination reduction to the central regions of chromosomes I and II. We show at the protein level that expression of rec8 is meiosis specific and that Rec8p localizes to approximately 100 foci per prophase nucleus. Rec8p was present in an unphosphorylated form early in meiotic prophase but was phosphorylated prior to meiosis I, as demonstrated by analysis of the mei4 mutant blocked before meiosis I. Evidence for the persistence of Rec8p beyond meiosis I was obtained by analysis of the mutant mes1 blocked before meiosis II. A human gene, which we designate hrec8, showed significant primary sequence similarity to rec8 and was mapped to chromosome 14. High mRNA expression of mouse and human rec8 genes was found only in germ line cells, specifically in testes and, interestingly, in spermatids. hrec8 was also expressed at a low level in the thymus. Sequence similarity and testis-specific expression indicate evolutionarily conserved functions of Rec8p in meiosis. Possible roles of Rec8p in the integration of different meiotic events are discussed.

Fos family members induce cell cycle entry by activating cyclin D1

Expression of the fos family of transcription factors is stimulated by growth factors that induce quiescent cells to reenter the cell cycle, but the cellular targets of the Fos family that regulate cell cycle reentry have not been identified. To address this issue, mice that lack two members of the fos family, c-fos and fosB, were derived. The fosB-/- c-fos-/- mice are similar in phenotype to c-fos-/- mice but are 30% smaller. This decrease in size is consistent with an abnormality in cell proliferation. Fibroblasts derived from fosB-/- c-fos-/- mice were found to have a defect in proliferation that results at least in part from a failure to induce cyclin D1 following serum-stimulated cell cycle reentry. Although definitive evidence that c-Fos and FosB directly induce cyclin D1 transcription will require further analysis, these findings raise the possibility that c-Fos and FosB are either direct or indirect transcriptional regulators of the cyclin D1 gene and may function as a critical link between serum stimulation and cell cycle progression.

Myc requires distinct E2F activities to induce S phase and apoptosis

Previous work has shown that the Myc transcription factor induces transcription of the E2F1, E2F2, and E2F3 genes. Using primary mouse embryo fibroblasts deleted for individual E2F genes, we now show that Myc-induced S phase and apoptosis requires distinct E2F activities. The ability of Myc to induce S phase is impaired in the absence of either E2F2 or E2F3 but not E2F1 or E2F4. In contrast, the ability of Myc to induce apoptosis is markedly reduced in cells deleted for E2F1 but not E2F2 or E2F3. From this data, we propose that the induction of specific E2F activities is an essential component in the Myc pathways that control cell proliferation and cell fate decisions.

The neuroprotective agent riluzole inhibits release of glutamate and aspartate from slices of hippocampal area CA1

Riluzole is believed to exert its anticonvulsant and neuroprotective actions by reducing glutamate release. This study demonstrated that 10-30 microM riluzole reduces the K(+)-evoked release of glutamate and aspartate from slices of hippocampal area CA1. Only higher concentrations reduced gamma-aminobutyrate (GABA) release. These actions of riluzole were not occluded by tetrodotoxin. Riluzole did not diminish the ability of glutamate analogues to depolarize CA1 pyramidal cells, as determined from grease-gap recordings. Therefore the anticonvulsant and neuroprotective actions of riluzole in the hippocampus may be at least partly explained by its ability to inhibit glutamate/aspartate release from synaptic terminals.

Angiographic findings and outcome in diabetic patients treated with thrombolytic therapy for acute myocardial infarction: the GUSTO-I experience

OBJECTIVES

This study sought to determine whether diabetes mellitus, in the setting of thrombolysis for acute myocardial infarction, affects 1) early infarct-related artery patency and reocclusion rates; and 2) global and regional ventricular function indexes. We also sought to assess whether angiographic or baseline clinical variables, or both, can account for the known excess mortality after myocardial infarction in the diabetic population.

BACKGROUND

Mortality after acute myocardial infarction in patients with diabetes is approximately twice that of nondiabetic patients. It is uncertain whether this difference in mortality is due to a lower rate of successful thrombolysis, increased reocclusion after successful thrombolysis, greater ventricular injury or a more adverse angiographic or clinical profile in diabetic patients.

METHODS

Patency rates and global and regional left ventricular function were determined in patients enrolled in the GUSTO-I Angiographic Trial. Thirty-day mortality differences between those with and without diabetes were compared.

RESULTS

The diabetic cohort had a significantly higher proportion of female and elderly patients, and they were more often hypertensive, came to the hospital later and had more congestive heart failure and a higher number of previous myocardial infarctions and bypass surgery procedures. Ninety-minute patency (Thrombolysis in Myocardial Infarction [TIMI] flow grade 3) rates in patients with and without diabetes were 40.3% and 37.6%, respectively (p = 0.7). Reocclusion rates were 9.2% vs. 5.3% (p = 0.17). Ejection fraction at 90 min after thrombolysis was similar in diabetic and nondiabetic patients ([mean +/- SEM] 6.10 +/- 1.6% vs. 60.1 +/- 0.7%, p = 0.7), as was regional ventricular function (number of abnormal chords: 19.1 +/- 2.0 vs. 17.5 +/- 0.8, p = 0.3; SD/chord: -2.3 +/- 0.2 vs. -2.4 +/- 0.1, p = 0.6). Diabetic patients had less compensatory hyperkinesia in the noninfarct zone (SD/ chord: 1.3 +/- 0.2 vs. 1.7 +/- 0.1, p < or = 0.01). No significant difference in ventricular function was noted at 5- to 7-day follow-up. The 30-day mortality rate was 11.3% in diabetic versus 5.9% in nondiabetic patients (p < or = 0.0001). After adjustment for clinical and angiographic variables, diabetes remained an independent determinant of 30-day mortality (p = 0.02).

CONCLUSIONS

Early (90-min) infarct-related artery patency as well as regional and global ventricular function do not differ between patients with and without diabetes after thrombolytic therapy, except for reduced compensatory hyperkinesia in the noninfarct zone among patients with diabetes. Diabetes remained an independent determinant of 30-day mortality after correction for clinical and angiographic variables.

Lithographically patterned nanowire electrodeposition

Nanowire fabrication methods can be classified either as 'top down', involving photo- or electron-beam lithography, or 'bottom up', involving the synthesis of nanowires from molecular precursors. Lithographically patterned nanowire electrodeposition (LPNE) combines attributes of photolithography with the versatility of bottom-up electrochemical synthesis. Photolithography defines the position of a sacrificial nickel nanoband electrode, which is recessed into a horizontal trench. This trench acts as a 'nanoform' to define the thickness of an incipient nanowire during its electrodeposition. The electrodeposition duration determines the width of the nanowire. Removal of the photoresist and nickel exposes a polycrystalline nanowire--composed of gold, platinum or palladium--characterized by thickness and width that can be independently controlled down to 18 and 40 nm, respectively. Metal nanowires prepared by LPNE may have applications in chemical sensing and optical signal processing, and as interconnects in nanoelectronic devices.

Regulation of cyclic AMP response element-binding protein (CREB) phosphorylation by acute and chronic morphine in the rat locus coeruleus

Previous studies have implicated adaptations in the cyclic AMP system in mechanisms of opiate tolerance, dependence, and withdrawal in the rat locus coeruleus. It has been speculated that such adaptations may occur at the level of gene expression. To understand better the mechanism by which opiates produce these intracellular adaptations, we studied morphine regulation of the state of phosphorylation of cyclic AMP response element-binding protein (CREB), a transcription factor that mediates some of the effects of the cyclic AMP system on gene expression. We show here, by use of a back phosphorylation and immunoprecipitation procedure, that acute morphine decreases the state of phosphorylation of CREB, an effect that becomes completely attenuated after chronic morphine administration. In contrast, acute precipitation of opiate withdrawal, via administration of an opiate receptor antagonist, increases the phosphorylation state of CREB. Such regulation of CREB phosphorylation could be part of the molecular pathway by which opiates produce changes in gene expression that lead to addiction.

L-type voltage-sensitive Ca2+ channel activation regulates c-fos transcription at multiple levels

A mechanism by which voltage-sensitive Ca2+ channel (VSCC) activation triggers c-fos transcription has been characterized. Ca2+ influx through VSCCs stimulates phosphorylation of the transcription factor cAMP response element-binding protein (CREB) on serine 133 leading to an increase in the formation of transcription complexes that can elongate through a transcription pause site within the c-fos gene. Ca(2+)-stimulated CREB serine 133 phosphorylation is mediated by a Ca(2+)-activated kinase and is not dependent on the cAMP-dependent protein kinase (PKA). While necessary for c-fos transcriptional induction following VSCC opening, CREB serine 133 phosphorylation is not sufficient for transcriptional activation. A second, PKA-dependent event is required. Following induction, c-fos transcription is rapidly down-regulated. Dephosphorylation of CREB serine 133 parallels and likely mediates the transcriptional shut-off event. These results suggest that the phosphorylation and dephosphorylation of CREB controls its ability to regulate transcription in membrane-depolarized cells and that multiple pathways contribute to Ca(2+)-activated gene expression.

Structure of the gene encoding peripherin, an NGF-regulated neuronal-specific type III intermediate filament protein

We have cloned the rat gene encoding peripherin, a neuronal-specific intermediate filament protein that is NGF-regulated. Determination of the complete sequence, including 821 nucleotides of the 5'-flanking region, allows us to make conclusions about the evolutionary origin of the peripherin gene, its homology with other intermediate filament proteins, and possible mechanisms of regulation of peripherin expression in neurons. The positions of the eight peripherin gene introns correspond to the intron patterns of desmin, vimentin, and GFAP, with one example of intron sliding. Together with protein sequence homologies, this conclusively demonstrates that peripherin is a type III intermediate filament protein. The peripherin promoter contains sequences homologous to regions of other NGF-regulated promoters, which may function in peripherin induction by NGF.

Gender and acute myocardial infarction: is there a different response to thrombolysis?

OBJECTIVES

This study sought to 1) determine the effect of gender on early and late infarct-related artery patency and reocclusion after thrombolytic therapy for acute myocardial infarction; 2) examine the effect of gender on left ventricular function in response to injury/reperfusion; and 3) assess the independent contribution of gender to early (30-day) mortality after acute myocardial infarction.

BACKGROUND

Women have a higher mortality rate than men after myocardial infarction. However, the effect of gender on infarct-related coronary artery patency and left ventricular response to injury/reperfusion have not been fully defined in the thrombolytic era.

METHODS

Patency rates and global and regional left ventricular function were determined in patients at 90 min and 5 to 7 days after thrombolytic therapy for acute myocardial infarction. The effect of gender on infarct-related artery patency and left ventricular function was determined. Thirty-day mortality differences between women and men were compared.

RESULTS

Women were significantly older and had more hypertension, diabetes, hypercholesterolemia, heart failure and shock. They were less likely to have had a previous myocardial infarction, history of smoking or previous bypass surgery. Ninety-minute patency rates (Thrombolysis in Myocardial Infarction [TIMI] flow grade 3) in women and men were 39% and 38%, respectively (p = 0.5). Reocclusion rates were 8.7% in women versus 5.1% in men (p = 0.14). Women had more recurrent ischemia than men (21.4% vs. 17.0%, respectively, p = 0.01). Ninety-minute ejection fraction and regional ventricular function were clinically similar in women and men with TIMI 2 or 3 flow (ejection fraction [mean +/- SD]: 63.4 +/- 6% vs. 59.4 +/- 0.7%, p = 0.02; number of chords: 21.4 +/- 0.9 vs. 21.0 +/- 1.9, p = 0.7; SD/chord: -2.4 +/- 08 vs. -2.4 +/- 0.2, p = 0.9, respectively). No clinically significant differences in left ventricular function were noted at 5- to 7-day follow-up. Women had a greater hyperkinetic response than men in the noninfarct zone (SD/chord: 2.4 +/- 0.2 vs. 1.7 +/- 0.1, p = 0.005). The 30-day mortality rate was 13.1% in women versus 4.8% in men (p < or = 0.0001). After adjustment for other clinical and angiographic variables, gender remained an independent determinant of 30-day mortality.

CONCLUSIONS

Women do not differ significantly from men with regard to either early infarct-related artery patency rates or reocclusion after thrombolytic therapy or ventricular functional response to injury/reperfusion. Gender was an independent determinant of 30-day mortality after acute myocardial infarction.

Cyclin D1 and D3 associate with the SCF complex and are coordinately elevated in breast cancer

D-type cyclins are important cell cycle regulators that promote cellular proliferation in response to growth factors by inactivation of the retinoblastoma protein (Rb). Cyclin D1 has been shown to be overexpressed in several cancer types and to act as an oncogene in breast cancers. As D-type cyclins are rate limiting for progression into S phase, the level at which they accumulate must be carefully regulated. Several mechanisms leading to overexpression of cyclin D1 have been reported including amplification, translocation and stabilization of the mRNA. Here, we present data showing elevated cyclin D1 protein in breast cancer samples in the absence of elevated mRNA level. Further, we found that in these cases, cyclin D3 protein also accumulates and that the coordinate increase in cyclin D1 and D3 occurs in 15% (7/47) of breast cancers. In addition we show that blocking the activity of the 26S proteosome results in the accumulation of cyclin D1 and D3, that both D-type cyclins are ubiquitinated and associate with Cul-1, a component of the SCF ubiquitin ligase complex. Finally, we show that the coordinated elevation of cyclin D1 and D3 is also observed in the breast cell line MCF-7 and demonstrate that the degradation of cyclin D1 and D3 is deficient in this cell line. These results indicate that cyclin D1 and cyclin D3 share a common mechanism of degradation and we propose that the coordinate increase of D-type cyclins observed in primary breast cancers reflects a defect in their proteolysis.

Weekly fluconazole for the prevention of mucosal candidiasis in women with HIV infection. A randomized, double-blind, placebo-controlled trial. Terry Beirn Community Programs for Clinical Research on AIDS

BACKGROUND

Candidiasis is a frequent complication of infection with the human immunodeficiency virus (HIV); however, few data exist about the natural history, prevention, and treatment of mucosal candidiasis in women.

OBJECTIVE

To evaluate the safety and effectiveness of weekly fluconazole prophylaxis for mucosal candidiasis in women infected with HIV.

DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING

14 sites participating in the Community Programs for Clinical Research on AIDS (CPCRA).

PATIENTS

323 women with HIV infection and CD4+ cell counts of 300 cells/mm3 or less.

INTERVENTION

200 mg of fluconazole per week or placebo. Open-label fluconazole for candidiasis prophylaxis was permitted after two oropharyngeal or vaginal episodes or one esophageal episode.

MEASUREMENTS

Development of mucosal candidiasis, clinical and in vitro resistance of Candida species to fluconazole, survival, and adverse events.

RESULTS

After a median follow-up of 29 months, 72 of 162 patients receiving fluconazole and 93 of 161 patients receiving placebo had at least one episode of candidiasis (relative risk [RR], 0.56 [95% Cl, 0.41 to 0.77); P < 0.001). Weekly fluconazole was effective in preventing oropharyngeal candidiasis (RR, 0.50 [Cl, 0.33 to 0.74]; P < 0.001) and vaginal candidiasis (RR, 0.64 [Cl, 0.40 to 1.00]; P = 0.05) but not esophageal candidiasis (RR, 0.91 [Cl, 0.48 to 1.72]; P > 0.2). Relative risks were similar for women who had a history of mucosal candidiasis (RR, 0.5 [Cl, 0.35 to 0.75]) and those who did not (RR, 0.69 [Cl, 0.35 to 1.34]). Absolute risk reduction for patients with a history of infection was 25.6 per 100 person-years, which is more than twice the reduction of 11.2 per 100 person-years seen in patients with no history of infection. This difference reflects the higher risk of patients who previously had an infection. Candida albicans was not usually resistant to fluconazole in vaginal specimens in clinical or in vitro settings; such resistance occurred in less than 5% of patients in each group.

CONCLUSIONS

Weekly fluconazole (200 mg) seems to be safe and effective in preventing oropharyngeal and vaginal candidiasis. This regimen has a useful role in the management of HIV-infected women who are at risk for recurrent mucosal candidiasis.

Myb: an old oncoprotein with new roles

Over the last decade, the c-myb gene and its protein product, Myb, have undergone extensive examination and manipulation in hemopoietic tissues. Although it is rarely disputed that, as a transcription factor, Myb regulates cell cycling, proliferation and differentiation, identification of genes directly controlled by Myb has been surprisingly difficult. More recently, genes with promoter regions that contain Myb recognition sequences have been identified, but a direct proliferative response to Myb via these 'target genes' has yet to be demonstrated. Mutagenesis studies have defined domains of the protein which influence its transcriptional activity and transforming potential; however how the molecule interacts with itself and with other cellular factors is only beginning to be understood. A broader examination of c-myb expression in normal and malignant tissues suggests an analogous role for Myb in proliferation, differentiation and transformation of non-hemopoietic tissues.

Doppler guide wire flow-velocity indexes measured distal to coronary stenoses associated with reversible thallium perfusion defects

A Doppler guide wire was used to measure phasic coronary blood flow velocity distal to coronary stenoses in 17 symptomatic patients with corresponding positive exercise or adenosine thallium scintigrams. Distal average peak velocity and diastolic/systolic flow-velocity ratio were obtained in 16 vessels with stenoses (55% to 85% diameter stenosis) and a corresponding reversible thallium defect and in 11 control vessels with no stenosis or thallium defect. Coronary flow-velocity reserve was obtained with intracoronary adenosine. Coronary flow reserve (2.3 +/- 0.4 vs 1.2 +/- 0.3, p < 0.01) and diastolic/systolic flow-velocity ratio (1.95 +/- 0.56 vs 1.44 +/- 0.59, p < 0.04) were significantly different between normal vessels and distal to stenoses, respectively. Excellent concordance between distal coronary flow reserve and diastolic/systolic flow-velocity ratio to thallium scintigraphy was noted. A coronary flow reserve of < 1.8 and a diastolic/systolic flow-velocity ratio of < 1.7 predicted a reversible thallium perfusion scintigram (concordance 96% and 88%, respectively). Distal coronary flow velocity indexes may provide an alternative means of physiologic assessment of lesion severity during coronary angiography.