ST-Segment recovery adds to the assessment of TIMI 2 and 3 flow in predicting infarct wall motion after thrombolytic therapy

BACKGROUND

Early resolution of ST-segment elevation (ST-segment recovery) is associated with an improved outcome after infarction. Whether this relation is present in patients with Thrombolysis In Myocardial Infarction (TIMI) grade 2 or 3 flow (ie, patent) infarct-related arteries is not known.

METHODS AND RESULTS

To examine the associations between time to achieve stable 50% ST-segment recovery assessed by continuous ECG monitoring, infarct artery flow, and infarct zone wall motion (at 48 hours), we studied 134 patients who underwent angiography at 99 (interquartile range 92 to 110) minutes after commencing streptokinase, initiated within 12 hours of onset of symptoms of myocardial infarction. Patients with TIMI 2 or 3 flow who failed to achieve early stable ST-segment recovery (50% ST-segment recovery sustained for > or 4 hours with <100 microV change in the peak lead) by 60 or 90 minutes had a higher fraction of chords in the infarct zone >2 SD below normal wall motion (TIMI 2: 55.5% vs 15.3%, P=0.006; and 56.5% vs 26.8%, P=0.01, respectively; and TIMI 3: 48.8% vs 28.3%, P=0.07; and 51.8% vs 29.9%, P=0.03, respectively). Time to stable ST-segment recovery was a multivariate predictor of infarct zone wall motion (P=0.04) independent of TIMI flow grade and the time from symptom onset to streptokinase therapy.

CONCLUSIONS

In patients with TIMI 2 or 3 flow in infarct-related artery, early stable ST-segment recovery is associated with improved infarct zone wall motion at 48 hours. ST-segment recovery may provide additional information about the degree of myocyte reperfusion achieved in patients with a patent epicardial infarct-related artery after thrombolytic therapy.

Dorsal thoracic cord compression from a spinal angiolipoma: case report and brief comment

Angiolipomas are benign tumors usually found in the forearms of young adults. To the best of our knowledge only 63 cases of spinal angiolipomas have been reported in the literature up until 1999 (MEDLINE 1966-1999). We report a case of a spinal angiolipoma causing dorsal cord compression in a 44-year-old woman presenting with subacute lower limb paresthesias, in the absence of sensory or motor findings, which mimicked multiple sclerosis by history. Operative intervention was curative.

ASW: a gene with conserved avian W-linkage and female specific expression in chick embryonic gonad

Vertebrates exhibit a variety of sex determining mechanisms which fall broadly into two classes: environmental or genetic. In birds and mammals sex is determined by a genetic mechanism. In mammals males are the heterogametic sex (XY) with the Y chromosome acting as a dominant determiner of sex due to the action of the testis-determining factor, SRY. In birds females are the heterogametic sex (ZW); however, it is not known whether the W chromosome carries a dominant ovary-determining gene, or whether Z chromosome dosage determines sex. Using an experimental approach, which assumes only that the sex-determining event in birds is accompanied by sex-specific changes in gene expression, we have identified a novel gene, ASW (Avian Sex-specific W-linked). The putative protein for ASW is related to the HIT (histidine triad) family of proteins. ASW shows female-specific expression in genital ridges and maps to the chicken W chromosome. In addition, we show that, with the exception of ratites, ASW is linked to the W chromosome in each of 17 bird species from nine different families of the class Aves.

Relationship between corrected TIMI frame counts at three weeks and late survival after myocardial infarction

OBJECTIVES

To evaluate the corrected Thrombolysis in Myocardial Infarction (TIMI) frame count (CTFC) as a predictor of late survival after myocardial infarction.

BACKGROUND

Thrombolysis in Myocardial Infarction flow grades predict late survival after myocardial infarction. The CTFC provides a more reproducible measurement of infarct-related artery blood flow than the TIMI flow grade, and has been linked to 30-day outcomes, but it has not yet been established how the CTFC correlates with late survival.

METHODS

Of 1,001 patients with acute myocardial infarction presenting within 4 h of symptom onset, 882 underwent angiography at approximately three weeks. Infarct artery flow was assessed, blinded to clinical outcomes, according to the CTFC and TIMI flow grade. Late cardiac mortality and survival were determined in 97.5% of patients.

RESULTS

The mean CTFC was 40 +/- 29 in 644 patent infarct arteries (median, 34 [interquartile range, 24 to 47]). The CTFC, assessed as a continuous univariate variable, was found to be a predictor of five-year survival, as was the TIMI flow grade (both p < 0.001). On multivariate analysis, factors associated with five-year survival included the ejection fraction or end-systolic volume index (both p < 0.001); exercise duration (p = 0.005), age (p = 0.008), diabetes (p = 0.02) and CTFC (p = 0.02) or TIMI flow (p = 0.02). The same factors, except for the CTFC and TIMI flow grade, were predictors of 10-year survival.

CONCLUSIONS

The CTFC three weeks after myocardial infarction was an independent predictor of five-year survival, but not 10-year survival. Although the CTFC provided additional prognostic information within TIMI flow grades, its superiority was not demonstrated.

New Q waves on the presenting electrocardiogram independently predict increased cardiac mortality following a first ST-elevation myocardial infarction

AIMS

The prognostic significance of pathological Q waves appearing in the acute phase of myocardial infarction has not been determined. We investigated whether new Q waves on the presenting electrocardiogram of patients with acute ST-segment elevation were independently associated with a worse outcome after a first myocardial infarction.

METHODS AND RESULTS

The presence or absence of new Q waves on the presenting electrocardiogram was assessed in 481 patients who presented within 4 h of symptom onset and were randomized to receive either captopril or placebo within 2 h of streptokinase therapy for myocardial infarction. Ventriculography was performed at 22+/-6 days and mortality status was obtained at a median follow-up of 5.6 years. New Q waves were associated with a lower ejection fraction (51+/-13% vs 61+/-12%, P<0.0001), a larger end-systolic volume index (37 ml vs 28 ml, P<0.001), and increased cardiac mortality at 30 days (7% vs 2%, P=0.01) and at follow-up (17% vs 7%, P=0.002). On multivariate analysis, age (P<0.01), new Q waves at presentation (P<0.01) and a history of angina (P=0.046) were independent predictors of cardiac mortality, whereas randomization to captopril and the time from symptom onset to streptokinase administration were not.

CONCLUSION

New Q waves at presentation are independently associated with a worse outcome after a first myocardial infarction. The presence of new Q waves on the presenting electrocardiogram allows very early identification of patients at risk of increased cardiac mortality.

Providing health care for lesbian clients

Health and nursing care for lesbian clients should be culturally congruent with their values and lifestyle. Barriers that lesbian clients encounter in the health care system are discussed, along with strategies that health care providers can use to overcome these barriers. Professional literature is reviewed that incorporates health promotion and maintenance issues influencing lesbian health care. Culturally appropriate services that are available in one women's health center are described, and resources for interested health care providers are provided.

A comparison of antimicrobial resistance rates in Gram-positive pathogens isolated in the UK from October 1996 to January 1997 and October 1997 to January 1998

Rates of resistance for two consecutive years for 28 centres (10 Teaching, nine Associate Teaching and nine District General hospitals) in the UK were compared. Combined rates of resistance for each of the hospital types of Staphylococcus aureus to methicillin revealed an increase in the rate of resistance in Teaching hospitals (12.5% year 1, 23.5% year 2), but, for Associate Teaching and District General hospitals rates fell (Associate Teaching 19.1% year 1, 11.9% year 2; District General 16.5% year 1 and 11.3% year 2). Using conventional methodology to determine MICs, no strain was considered to have reduced susceptibility to vancomycin. Among coagulase-negative staphylococci, increased resistance was observed for Staphylococcus epidermidis to rifampicin, for Staphylococcus haemolyticus to clindamycin, for Staphylococcus saprophyticus to penicillin and for Staphylococcus spp. to clindamycin, methicillin and rifampicin. For Streptococcus pneumoniae an upward trend in low-level resistance to penicillin was observed (18 of the 28 centres), however, for high-level resistance the trend was in the opposite direction (only four centres showed an increase). For Enterococcus faecalis there was a trend to a fall in levels of resistance, the only exception being an increase in high-level gentamicin resistance (10.5% year 1, 15.1% year 2, P = 0.0388). For Enterococcus faecium rates of resistance were not significantly different except for increases in resistance to nitrofurantoin and rifampicin.

OVO transcription factors function antagonistically in the Drosophila female germline

OVO controls germline and epidermis differentiation in flies and mice. In the Drosophila germline, alternative OVO-B and OVO-A isoforms have a common DNA-binding domain, but different N-termini. We show that these isoforms are transcription factors with opposite regulatory activities. Using yeast one-hybrid assays, we identified a strong activation domain within a common region and a counteracting repression domain within the OVO-A-specific region. In flies, OVO-B positively regulated the ovarian tumor promoter, while OVO-A was a negative regulator of the ovarian tumor and ovo promoters. OVO-B isoforms supplied ovo(+) function in the female germline and epidermis, while OVO-A isoforms had dominant-negative activity in both tissues. Moreover, elevated expression of OVO-A resulted in maternal-effect lethality while the absence of OVO-A resulted in maternal-effect sterility. Our data indicate that tight regulation of antagonistic OVO-B and OVO-A isoforms is critical for germline formation and differentiation.

The kidney is an important site for in vivo phenylalanine-to-tyrosine conversion in adult humans: A metabolic role of the kidney

Synthesis of Tyr in the human body occurs by hydroxylation of the indispensable amino acid Phe. Until now, it was believed that in humans, this process was restricted to the liver, but we provide compelling evidence of production of Tyr from Phe in the kidney. To determine whether the human kidney produces Tyr, we measured Tyr balance, the Tyr appearance rate, and the Phe-to-Tyr conversion in 12 healthy human subjects by using [(15)N]Phe and [(2)H(4)]Tyr as tracers. Renal plasma flow was measured by using paraaminohippurate, and sampling from the femoral artery and renal veins was performed. The results were compared with those obtained in 12 control subjects undergoing hepatic vein catheterization and infusion of identical tracers. In all 12 subjects, there was a net uptake of Phe by the kidney (2.2 +/- 1.2 micromol/min), whereas Tyr was released (5.3 +/- 1.5 micromol/min). In contrast, there was a net uptake of both Phe (9.5 +/- 1.2 micromol/min) and Tyr (14.3 +/- 1.3 micromol/min) by the splanchnic bed. Phe conversion to Tyr occurred at a rate of 5.2 +/- 1.2 micromol/min in kidney and 3.0 +/- 0.7 micromol/min in the splanchnic bed. The kidney contributed a substantial amount of Tyr to the systemic circulation where the splanchnic bed was a net remover of Tyr. Our results demonstrate that the kidney is the major donor of Tyr to the systemic circulation by its conversion of Phe to Tyr. This observation may have important clinical implications for patients with both renal and hepatic disease, who may be at risk of Phe overloading and Tyr deficiency, and it should be considered when parenteral or enteral nutrients are administered rich in Phe and low in Tyr.

Effect of physiological mechanical perturbations on intact human myocardial repolarization

OBJECTIVE

The objective of this study was to investigate the relationship between acute decreases in right ventricular volume during Valsalva strain (with resultant changes in autonomic neural tone) and measures of local endocardial repolarization time independent of heart rate and autonomic neural tone.

METHODS

Patients implanted with a stimulus to T wave (Stim-T) sensing pacemaker specially adapted to output a validate measure of beat to beat local repolarization (n = 9) performed Valsalva manoeuvers (40 mmHg for 15 s) while paced at a cycle length of 500 ms. Stim-T intervals were measured before and after autonomic blockade (Block: 0.03 mg/kg i.v. atropine +/- 0.15 mg/kg propranolol). Right ventricular end diastolic volume was estimated by simultaneous 2D-echocardiography.

RESULTS

Without autonomic blockade, compared to baseline, repolarization significantly prolonged during Valsalva strain (1.1 +/- 0.7%) and shortened during release (-1.4 +/- 1.0%). After block, strain related repolarization prolongation was also observed (1.0 +/- 0.6%), with significantly less release related repolarization shortening (-0.8 +/- 0.8%) compared to pre-block (P < 0.05). Right ventricular end diastolic volume decreased during strain by 11 +/- 10 and 9 +/- 16% from baseline, pre- and post-block respectively (P < 0.05).

CONCLUSION

In a chronically instrumented human model, an acute physiologic volume reduction modestly prolongs right ventricular repolarization independent of changes in rate or autonomic tone.

Regulated expression of green fluorescent protein under the control of Aureobasidium pullulans xylanase gene xynA

A mutant form of the jellyfish cDNA encoding green fluorescent protein (GFP) was fused to the promoter of the Aureobasidium pullulans xylanase gene xynA and the expression vector pxynEGFP was introduced into A. pullulans. In a manner consistent with regulation of the native xynA gene, gfp activity was induced by xylose and repressed by glucose. The marker may be useful for monitoring populations of A. pullulans in situ and for identifying transcriptional control elements of xynA.

Concentrations of moxifloxacin in serum and pulmonary compartments following a single 400 mg oral dose in patients undergoing fibre-optic bronchoscopy

The concentrations of moxifloxacin achieved after a single 400 mg dose were measured in serum, epithelial lining fluid (ELF), alveolar macrophages (AM) and bronchial mucosa (BM). Concentrations were determined using a microbiological assay. Nineteen patients undergoing fibre-optic bronchoscopy were studied. Mean serum, ELF, AM and BM concentrations at 2.2, 12 and 24 h were as follows: 2.2 h: 3.2 mg/L, 20.7 mg/L, 56.7 mg/L, 5.4 mg/kg; 12 h: 1.1 mg/L, 5.9 mg/L, 54.1 mg/L, 2.0 mg/kg; 24 h: 0.5 mg/L, 3.6 mg/L, 35.9 mg/L, 1.1 mg/kg, respectively. These concentrations exceed the MIC(90)s for common respiratory pathogens such as Streptococcus pneumoniae (0.25 mg/L), Haemophilus influenzae (0.03 mg/L), Moraxella catarrhalis (0.12 mg/L), Chlamydia pneumoniae (0.12 mg/L) and Mycoplasma pneumoniae (0. 12 mg/L) and indicate that moxifloxacin should be effective in the treatment of community-acquired, lower respiratory tract infections.

Refrigerated storage improves the stability of the complete blood cell count and automated differential

A CBC count was performed on 113 random patient and 21 control specimens before and after 24-hour room temperature (RT) storage; 98 random patient and 20 control specimens also were analyzed before and after 24 hour 4 degrees C storage. The Cell-Dyn 3500 (Abbott Laboratories, Abbott Park, IL) was used for analysis. RT storage showed a decline in WBC count using the optical but not the impedance method, resulting in a large number of WBC flags. An increase in mean corpuscular volume also was seen for patient specimens. The automated WBC differential showed a decrease in the percentage of neutrophils and an increase in the percentage of lymphocytes, owing primarily to neutrophil degeneration. These changes also were seen in the manual differential to a similar degree. Storage of specimens at 4 degrees C largely prevented all of these changes. The implementation of refrigerated specimen storage is a simple, inexpensive method to improve the accuracy of CBC results for aged specimens on automated hematology analyzers.

Attaining role confirmation in nurse practitioner practice

Although nurse practitioners (NPs) as a collective group have reached the stage of role confirmation, in new settings they must transition through several phases of role development. The role confirmation issues for a team of NPs who were hired to work in a large academic teaching hospital in the Southeastern part of the United States are explored over a 3-year period. Characteristics of the organization and strategies that the NPs implemented over time impacted favorably on the evolution of the NP role in that setting. The NPs gained prescriptive privileges, independent practice, and market-place salaries. Effective negotiation and marketing strategies enhanced both personal and professional development.

Analysis of factors that correlate with mucositis in recipients of autologous and allogeneic stem-cell transplants

PURPOSE

To identify predictors of oral mucositis and gastrointestinal toxicity after high-dose therapy.

PATIENTS AND METHODS

Mucositis and gastrointestinal toxicity were prospectively evaluated in 202 recipients of high-dose therapy and autologous or allogeneic stem-cell rescue. Of 10 outcome variables, three were selected as end points: the peak value for the University of Nebraska Oral Assessment Score (MUCPEAK), the duration of parenteral nutritional support, and the peak daily output of diarrhea. Potential covariates included patient age, sex, diagnosis, treatment protocol, transplantation type, stem-cell source, and rate of neutrophil recovery. The three selected end points were also examined for correlation with blood infections and transplant-related mortality.

RESULTS

A diagnosis of leukemia, use of total body irradiation, allogeneic transplantation, and delayed neutrophil recovery were associated with increased oral mucositis and longer parenteral nutritional support. No factors were associated with diarrhea. Also, moderate to severe oral mucositis (MUCPEAK > or = 18 on a scale of 8 to 24) was correlated with blood infections and transplant-related mortality: 60% of patients with MUCPEAK > or = 18 had positive blood cultures versus 30% of patients with MUCPEAK less than 18 (P =.001); 24% of patients with MUCPEAK > or = 8 died during the transplantation procedure versus 4% of patients with MUCPEAK less than 18 (P =.001).

CONCLUSION

Gastrointestinal toxicity is a major cause of transplant-related morbidity and mortality, emphasizing the need for corrective strategies. The peak oral mucositis score and the duration of parenteral nutritional support are useful indices of gastrointestinal toxicity because these end points are correlated with clinically significant events, including blood infections and treatment-related mortality.

Cost-effectiveness of treatment of early stage endometrial cancer

OBJECTIVE

The purpose of this study was to determine the average life-years gained and cost per life-year gained in treatment of early endometrial cancer.

METHODS

We performed a decision analysis using statistical models for survival after treatment for Stage I endometrial cancer. Estimates for survival probabilities without treatment, with surgery alone, and with surgery and radiation were derived from the literature. Charges and costs of treatment were estimated based on data from our institution. We calculated the average number of life-years gained and the cost per life-year gained of various treatment options based on these estimates. Sensitivity analyses were performed to determine the effect of uncertainty about parameter estimates on the results derived from our model.

RESULTS

Based on the assumptions of our model, most of the life-years gained in treatment of early endometrial cancer are attributable to hysterectomy, with a very low associated cost. For the "average" woman with endometrial cancer, about 10 life-years are gained from hysterectomy at a cost of $1000 per life-year gained, whereas adjuvant radiation yields on average 1 year of life gained at $4000 per life-year gained. Both life-years gained and cost are dramatically affected by age at diagnosis and to a lesser extent by histologic grade and comorbid medical conditions.

CONCLUSIONS

This analysis suggests that the use of hysterectomy and adjuvant radiation in treatment of early endometrial cancer is a worthwhile use of health care resources. More sophisticated models may help determine the cost-effectiveness of various treatment strategies in specific subgroups of patients.

Production of influenza-stimulated tumor necrosis factor-alpha by monocytes following acute influenza infection in humans

Tumor necrosis factor-alpha (TNF-alpha) is often measured in the serum or plasma of patients with severe infections, and marked elevation correlates with poor outcome. The relationship of TNF-alpha to protection from disease is frequently not observed because prospective studies of infectious agents are difficult to perform. We took advantage of a human antiviral influenza challenge study to correlate TNF-alpha production with seroconversion and symptom development. TNF-alpha production was measured by ELISA in the plasma compartment or was measured by intracellular production at the single cell level in the monocyte gated population. Monocyte TNF-alpha was associated with asymptomatic seroconversion, whereas there was no change in the plasma at the times measured. Measurement of TNF-alpha at the single cell level by flow cytometry may allow for better differentiation of the protective role of this cytokine in future studies.

Maternal cigarette smoking and pregnancy outcome

Maternal smoking rates in pregnancy have declined, particularly in the non-manual social classes, and perinatal mortality rates have fallen over the last 20 years. We have therefore re-evaluated the relationship between maternal cigarette smoking and pregnancy outcome against this background. A total of 608 stillbirths and 634 infant deaths were identified using the All Wales Perinatal Survey. The cause of death was classified using the clinicopathological system. Maternal smoking rates and social class groupings were compared with those in a cohort of 16047 survivors born to women resident in South Glamorgan. The smoking rate was 37.8% in mothers of babies who died compared with 27.2% in mothers of survivors, an odds ratio (OR) of 1.63 [95% CI 1.44, 1.84]. The OR for unexplained stillbirth was 1.72 [95% CI 1.38, 2.13], placental abruption 2.07 [95% CI 1.29, 3.31], infection 3.70 [95% CI 2.23, 6.13] and sudden infant death syndrome 4.84 [95% CI 3.05, 7.69]. Maternal smoking was not associated with death due to prematurity or a congenital anomaly. Despite changes in smoking habits and the causes of perinatal death, smoking during pregnancy continues to be strongly associated with fetal and infant mortality. It is important that health promotion activities are effective in reducing smoking during pregnancy.

beta-arrestins regulate interleukin-8-induced CXCR1 internalization

The functional role of neutrophils during acute inflammatory responses is regulated by two high affinity interleukin-8 receptors (CXCR1 and CXCR2) that are rapidly desensitized and internalized upon binding their cognate chemokine ligands. The efficient re-expression of CXCR1 on the surface of neutrophils following agonist-induced internalization suggests that CXCR1 surface receptor turnover may involve regulatory pathways and intracellular factors similar to those regulating beta2-adrenergic receptor internalization and re-expression. To examine the internalization pathway utilized by ligand-activated CXCR1, a CXCR1-GFP construct was transiently expressed in two different cell lines, HEK 293 and RBL-2H3 cells. While interleukin-8 stimulation promoted CXCR1 sequestration in RBL-2H3 cells, receptor internalization in HEK 293 cells required co-expression of G protein-coupled receptor kinase 2 and beta-arrestin proteins. The importance of beta-arrestins in CXCR1 internalization was confirmed by the ability of a dominant negative beta-arrestin 1-V53D mutant to block internalization of CXCR1 in RBL-2H3 cells. A role for dynamin was also demonstrated by the lack of CXCR1 internalization in dynamin I-K44A dominant negative mutant-transfected RBL-2H3 cells. Agonist-promoted co-localization of transferrin and CXCR1-GFP in endosomes of RBL-2H3 cells confirmed that receptor internalization occurs via clathrin-coated vesicles. Our data provides a direct link between agonist-induced internalization of CXCR1 and a requirement for G protein-coupled receptor kinase 2, beta-arrestins, and dynamin during this process.