Azimuthal charged-particle correlations and possible local strong parity violation

Parity-odd domains, corresponding to nontrivial topological solutions of the QCD vacuum, might be created during relativistic heavy-ion collisions. These domains are predicted to lead to charge separation of quarks along the system's orbital momentum axis. We investigate a three-particle azimuthal correlator which is a P even observable, but directly sensitive to the charge separation effect. We report measurements of charged hadrons near center-of-mass rapidity with this observable in Au + Au and Cu + Cu collisions at square root of s(NN) = 200 GeV using the STAR detector. A signal consistent with several expectations from the theory is detected. We discuss possible contributions from other effects that are not related to parity violation.

Growth of long range forward-backward multiplicity correlations with centrality in Au + Au collisions at square root of sNN = 200 GeV

Forward-backward multiplicity correlation strengths have been measured with the STAR detector for Au + Au and p + p collisions at square root of s(NN) = 200 GeV. Strong short- and long-range correlations (LRC) are seen in central Au + Au collisions. The magnitude of these correlations decrease with decreasing centrality until only short-range correlations are observed in peripheral Au + Au collisions. Both the dual parton model (DPM) and the color glass condensate (CGC) predict the existence of the long-range correlations. In the DPM, the fluctuation in the number of elementary (parton) inelastic collisions produces the LRC. In the CGC, longitudinal color flux tubes generate the LRC. The data are in qualitative agreement with the predictions of the DPM and indicate the presence of multiple parton interactions.

K/pi Fluctuations at relativistic energies

We report K/pi fluctuations from Au + Au collisions at sqrt[s(NN)]= 19.6, 62.4, 130, and 200 GeV using the STAR detector at the Relativistic Heavy Ion Collider. K/pi fluctuations in central collisions show little dependence on incident energy and are on the same order as those from NA49 at the Super Proton Synchrotron in central Pb + Pb collisions at sqrt[s(NN)]=12.3 and 17.3 GeV. We report results for the collision centrality dependence of K/pi fluctuations and results for charge-separated fluctuations. We observe that the K/pi fluctuations scale with the charged particle multiplicity density.

Observation of two-source interference in the photoproduction reaction AuAu --> AuAurho0

In ultraperipheral relativistic heavy-ion collisions, a photon from the electromagnetic field of one nucleus can fluctuate to a quark-antiquark pair and scatter from the other nucleus, emerging as a rho{0}. The rho{0} production occurs in two well-separated (median impact parameters of 20 and 40 F for the cases considered here) nuclei, so the system forms a two-source interferometer. At low transverse momenta, the two amplitudes interfere destructively, suppressing rho{0} production. Since the rho{0} decays before the production amplitudes from the two sources can overlap, the two-pion system can only be described with an entangled nonlocal wave function, and is thus an example of the Einstein-Podolsky-Rosen paradox. We observe this suppression in 200 GeV per nucleon-pair gold-gold collisions. The interference is 87%+/-5%(stat.)+/-8%(syst.) of the expected level. This translates into a limit on decoherence due to wave function collapse or other factors of 23% at the 90% confidence level.

Indications of conical emission of charged hadrons at the BNL relativistic heavy ion collider

Three-particle azimuthal correlation measurements with a high transverse momentum trigger particle are reported for pp, d+Au, and Au+Au collisions at sqrt[s_{NN}]=200 GeV by the STAR experiment. Dijet structures are observed in pp, d+Au and peripheral Au+Au collisions. An additional structure is observed in central Au+Au data, signaling conical emission of correlated charged hadrons. The conical emission angle is found to be theta=1.37+/-0.02(stat)-0.07+0.06(syst), independent of p_{ perpendicular}.

In situ and small invasive breast cancer register in Victoria, 1988 to 1992: Tumour characteristics and patient management

BACKGROUND

All cases of in situ and invasive breast cancer are reported to the Victorian Cancer Registry. In 1988 a special subregister of all cases of carcinoma in situ and small invasive cancers up to 10 mm in size was established--the In situ and Small Invasive Breast Cancer Register (ISSIBCR). This was unique in being a population-based register and only possible because in Victoria, as in some other Australian states, all cancers including in situ disease are reported to the Central Cancer Registry.

METHODS

Between 1 January 1988 and 31 December 1992, 517 cases of in situ cancers and 892 invasive cancers of < or =10 mm in diameter were registered. During the study period, mammography screening was progressively introduced in Victoria and the number of cases, in both categories registered annually, doubled.

RESULTS

The method of detection, the pathology and treatment of these lesions are described. It is of interest that 46.5% of the in situ cancers and 68.8% of the invasive cancers were detected either by the patient or her doctor on clinical examination. Total mastectomy was the method of treatment in 35.4% of in situ cancers and 42.0% of small invasive tumours. Only 38.0% of patients with small invasive cancers treated by breast-conserving surgery had irradiation of the affected breast.

CONCLUSIONS

This register provides a valuable resource for the follow up of the natural history and outcome of treatment of the affected women.

Nomenclature for ion channel subunits

Presents the nomenclature for ion channel subunits. Role of ion channels in the mediation of visual and olfactory signal transduction; Expression of ion channels in cell types and tissues; Assessment on the nucleotide sensitivity, ion conductance and calcium modulation in heteromers.

Pre-mRNA splicing and mRNA export linked by direct interactions between UAP56 and Aly

Recent studies indicate that splicing of pre-messenger RNA and export of mRNA are normally coupled in vivo. During splicing, the conserved mRNA export factor Aly is recruited to the spliced mRNA-protein complex (mRNP), which targets the mRNA for export. At present, it is not known how Aly is recruited to the spliced mRNP. Here we show that the conserved DEAD-box helicase UAP56, which functions during spliceosome assembly, interacts directly and highly specifically with Aly. Moreover, UAP56 is present together with Aly in the spliced mRNP. Significantly, excess UAP56 is a potent dominant negative inhibitor of mRNA export. Excess UAP56 also inhibits the recruitment of Aly to the spliced mRNP. Furthermore, a mutation in Aly that blocks its interaction with UAP56 prevents recruitment of Aly to the spliced mRNP. These data suggest that the splicing factor UAP56 functions in coupling the splicing and export machineries by recruiting Aly to the spliced mRNP.

A new view of mRNA export: separating the wheat from the chaff

Current models for the export of messenger RNA share the notion that the highly abundant class of nuclear RNA-binding proteins--the hnRNP proteins--have a key role in exporting RNA. But recent studies have led to a new understanding of several non-hnRNP proteins, including SR proteins and the conserved mRNA export factor ALY, which are recruited to the mRNA during pre-mRNA splicing. These studies, together with older work on hnRNP particles and assembly of the spliceosome, lead us to a new view of mRNA export. In our model, the non-hnRNP factors form a splicing-dependent mRNP complex that specifically targets mature mRNA for export, while hnRNP proteins retain introns in the nucleus. A machinery that is conserved between yeast and higher eukaryotes functions to export the mRNA.

Pregnancy following uterine fibroid embolization

OBJECTIVE

This paper seeks to evaluate the ability to deliver term pregnancies following uterine fibroid embolization, and to identify impediments to pregnancy in the embolization procedure.

STUDY DESIGN

Four physicians performed embolization procedures at various facilities. Patients were asked if fertility was an issue prior to embolization. We measured follicle-stimulating hormone levels before and after embolization. Clinical follow-up, six months following embolization was obtained by interview. Patients were questioned regarding attempts to conceive, menstrual history, and subsequent pregnancy.

MAIN OUTCOME MEASURES

Complications were calculated upon the entire patient population, whether or not fertility was identified as a goal. Fertility risks from embolization were identified. We measured radiation exposure in a random consecutive group of 50 women undergoing embolization. All patients who conceived were asked the details of the pregnancy.

RESULTS

Four hundred women underwent uterine fibroid embolization between 1996 and 1999. One hundred and thirty nine patients stated a desire for fertility after embolization. Of these, 52 were <40 years old. Seventeen pregnancies have been reported in 14 women. Five spontaneous abortions were observed. Ten women have had normal term deliveries and two women are currently pregnant. No perfusion problems, either during the pregnancy or labor, were reported. The average radiation dosage calculated for 50 women undergoing embolization was 14 rads. Four women under 45 years old suffered premature menopause (10/1000). Two women underwent hysterectomy as a complication of embolization (5/1000).

CONCLUSION

The risks of infertility following embolization, premature menopause, and hysterectomy are small, as is the radiation exposure during embolization. These risks compare favorably with those associated with myomectomy. Fertility rates appear similar to patients undergoing myomectomy. No problems, either during pregnancy or delivery, have been observed after embolization. The course of pregnancy and delivery was normal after embolization with no maternal or fetal complications reported. These findings confirm results from other centers. Desire for future pregnancy is not a contraindication to fibroid embolization.

EKG analysis skills of family practice residents in the United Arab Emirates: a comparison with US data

BACKGROUND AND OBJECTIVES

Concern has been raised about the electrocardiogram (EKG) analysis skills of family practice residents in the United States. This study examined EKG analysis skills of family practice residents, medical students, interns, and general practitioners (GPs) in the United Arab Emirates (UAE), a different environment.

METHODS

The measurement instrument was a set of 10 EKGs, used in a study of US family practice residents. Two of the EKGs were normal, and there were 14 clinical abnormalities in the remainder.

RESULTS

There was no significant difference in the correct diagnosis of acute myocardial infarction between US family practice residents and UAE family practice residents, medical students, or GPs. Interns' diagnoses were significantly poorer. The mean score for correctly identifying acute myocardial infarction and both normal EKGs was not significantly different between groups: 2.50 medical students, 2.35 interns, 2.58 UAE family practice residents, 2.67 FD, and 2.55 US family practice residents. However, the US family practice resident mean score of 11.26 for all 16 clinical findings was significantly higher than any group in the UAE: 5.35 medical students, 5.87 interns, 6.08 UAE family practice residents, 5.69 family physicians.

CONCLUSIONS

Difficulty in EKG interpretation transcends geographic boundaries, suggesting that new approaches to teaching these skills need to be explored. Improved EKG reading skills by family physicians are generally needed in both the United States and the UAE.

Erythema Gyratum Repens

BACKGROUND

Erythema gyratum repens is a rare, clinically specific, and distinctive paraneoplastic syndrome. It is associated with internal malignancy in 82% of patients.

OBJECTIVE

A 58-year-old man with erythema gyratum repens is described. On diagnosis of his eruption, a malignancy work-up revealed a 9-mm pulmonary adenocarcinoma. Removal of the carcinoma resulted in clearing of the erythema.

RESULTS

Erythema gyratum repens is most commonly associated with bronchial, esophageal, and breast cancer. It has also rarely been reported in patients without evidence of malignancy. The histopathologic findings are nonspecific. Direct immunofluorescence has sometimes revealed C3, C4, or immunoglobulin G at the basement membrane zone.

CONCLUSION

The etiology of erythema gyratum repens is unknown, although an immune response is postulated. Treatment involves treating the underlying malignancy.

An upstream AG determines whether a downstream AG is selected during catalytic step II of splicing

Specific mechanisms must exist to ensure fidelity in selecting the AG dinucleotide that functions as the 3' splice site during the second transesterification step of splicing. Here we show that the optimal location for this AG is within a narrow distance (19 to 23 nucleotides [nt]) downstream from the branch point sequence (BPS). Contrary to previous expectations, AGs located less than 23 nt from the BPS are always recognized, even when a second AG located more optimally downstream is used in the transesterification reaction. Indeed, the AG closest to the BPS actually dictates the precise location of the AG that engages in the reaction. This mechanism, in which the AG is identified by a general localization step followed by a precise localization step, may be used to achieve fidelity while allowing flexibility in the location of 3' splice sites.

A Ran-independent pathway for export of spliced mRNA

All major nuclear export pathways so far examined follow a general paradigm. Specifically, a complex is formed in the nucleus, containing the export cargo, a member of the importin-beta family of transporters and RanGTP. This complex is translocated across the nuclear pore to the cytoplasm, where hydrolysis of the GTP on Ran is stimulated by the GTPase-activating protein RanGAP. The activity of RanGAP is increased by RanBP1, which also promotes disassembly of RanGTP-cargo-transporter complexes. Here we investigate the role of RanGTP in the export of mRNAs generated by splicing. We show that nuclear injection of a Ran mutant (RanT24N) or the normally cytoplasmic RanGAP potently inhibits the export of both tRNA and U1 snRNA, but not of spliced mRNAs. Moreover, nuclear injection of RanGAP together with RanBP1 blocks tRNA export but does not affect mRNA export. These and other data indicate that export of spliced mRNA is the first major cellular transport pathway that is independent of the export co-factor Ran.

The protein Aly links pre-messenger-RNA splicing to nuclear export in metazoans

In metazoans, most pre-messenger RNAs contain introns that are removed by splicing. The spliced mRNAs are then exported to the cytoplasm. Recent studies showed that splicing promotes efficient mRNA export, but the mechanism for coupling these two processes is not known. Here we show that Aly, the metazoan homologue of the yeast mRNA export factor Yralp (ref. 2), is recruited to messenger ribonucleoprotein (mRNP) complexes generated by splicing. In contrast, Aly does not associate with mRNPs assembled on identical mRNAs that already have no introns or with heterogenous nuclear RNP (hnRNP) complexes. Aly is recruited during spliceosome assembly, and then becomes tightly associated with the spliced mRNP. Aly shuttles between the nucleus and cytoplasm, and excess recombinant Aly increases both the rate and efficiency of mRNA export in vivo. Consistent with its splicing-dependent recruitment, Aly co-localizes with splicing factors in the nucleus. We conclude that splicing is required for efficient mRNA export as a result of coupling between the splicing and the mRNA export machineries.