BACKGROUND

The indications for resurfacing of the glenoid in patients who have osteoarthritis of the shoulder are not clearly defined; some investigators routinely perform hemiarthroplasty whereas others perform total shoulder arthroplasty.

METHODS

Forty-seven patients (fifty-one shoulders) who were scheduled to have a shoulder arthroplasty for the treatment of degenerative osteoarthritis were randomly assigned, according to a random-numbers table, to one of two groups: replacement of the humeral head with resurfacing of the glenoid with a polyethylene component with cement (total shoulder arthroplasty [twenty-seven shoulders]) or replacement of the humeral head without resurfacing of the glenoid (hemiarthroplasty [twenty-four shoulders]). All patients received the same type of humeral component, and all operations were performed by or under the direct supervision of the same surgeon. The patients were followed for a mean of thirty-five months (range, twenty-four to seventy-two months) postoperatively. Evaluation was performed with use of the scoring systems of the University of California at Los Angeles and the American Shoulder and Elbow Surgeons.

RESULTS

No difference was observed between the preoperative scores for the two groups of patients. Postoperatively, the mean scores with use of the University of California at Los Angeles system and the American Shoulder and Elbow Surgeons system were 23.2 points (range, 10 to 31 points) and 65.2 points (range, 15 to 94 points), respectively, after hemiarthroplasty and 27.4 points (range, 9 to 34 points) and 77.3 points (range, 3 to 100 points), respectively, after total shoulder arthroplasty. With the numbers available for study, no significant difference was found between the two operative groups with respect to the postoperative score. (Thirty-five subjects per group would be needed, assuming an effect size of 0.60 and a power of 0.80.) Total shoulder arthroplasty provided significantly greater pain relief (p = 0.002) and internal rotation (p = 0.003) than hemiarthroplasty did. Total shoulder arthroplasty also provided superior results in the specific areas of patient satisfaction, function, and strength, although none of these differences were found to be significant, with the numbers available. Total shoulder arthroplasty was associated with increased cost ($1177), operative time (thirty-five minutes), and blood loss (150 milliliters) per patient compared with hemiarthroplasty. To date, none of the total shoulder arthroplasties in the study group have been revised. Hemiarthroplasty yielded equivalent results for elevation and external rotation. Three of the twenty-five patients who had had a hemiarthroplasty needed a subsequent operation for resurfacing of the glenoid. The mean cost for the revision operations was $15,998.

CONCLUSIONS

Total shoulder arthroplasty provided superior pain relief compared with hemiarthroplasty in patients who had glenohumeral osteoarthritis, but it was associated with an increased cost of $1177 per patient.

BACKGROUND

Conventional intraoperative nerve monitoring, predicated on intermittent stimulation, can predict recurrent laryngeal nerve (RLN) palsy only after the damage has been done.

METHODS

Fifty-two patients (52 nerves at risk) who underwent continuous intraoperative nerve monitoring (CIONM) for thyroid surgery via vagus nerve stimulation had their electromyographic (EMG) tracings recorded and correlated with surgical maneuvers and postoperative RLN function.

RESULTS

There was 1 imminent loss of signal (LOS) with intraoperative signal recovery and there were 4 losses of signal with corresponding unilateral transient RLN palsy. When EMG amplitude decreased >50% and EMG latency increased >10%, LOS and postoperative RLN palsy were noted in 4 of 8 patients (50%) who had multiple combined events. In 9 of 13 patients (70%) who developed adverse EMG changes, modification of the causative surgical maneuver resulted in recovery of those EMG changes and aversion of impending RLN palsy.

CONCLUSIONS

CIONM reliably signaled impending nerve injury, enabling immediate corrective action.

BACKGROUND

Although 15(S)-hydroxyeicosatetraenoic acid (15(S)-HETE), a product of 15-lipoxygenase (15-LO), may be involved in mild to moderate asthma, little is known about its potential roles in severe asthma.

OBJECTIVE

This study was performed to evaluate 15(S)-HETE levels in bronchoalveolar lavage fluid (BALF) from severe asthmatics with and without airway eosinophils and from the control groups. In addition, 15-LO protein expression was examined in endobronchial biopsy, while its expression and activation were evaluated in BAL cells.

RESULTS

While 15(S)-HETE levels in BALF were significantly higher in all severe asthmatics than normal subjects, severe asthmatics with airway eosinophils had the highest levels compared with mild, moderate asthmatics and normal subjects. 15(S)-HETE levels were associated with tissue eosinophil numbers, sub-basement membrane thickness and BALF tissue inhibitor of metalloproteinase-1 levels, and were accompanied by increased 15-LO expression in bronchial epithelium. In addition, activation of 15-LO was suggested by the increased proportion of 15-LO in the cytoplasmic membrane of alveolar macrophages from severe asthmatics.

CONCLUSIONS

The data suggest that severe asthmatics with persistent airway eosinophils manifest high levels of 15(S)-HETE in BALF, which may be associated with airway fibrosis. It is likely that 15-LO expression and activation by airway cells explain the increased 15(S)-HETE levels.

Despite the health and survival advantages of Hispanics relative to non-Hispanic whites in the USA, Hispanics report themselves to be in worse health than whites. Prior research indicates that these ethnic differences in self-rated health (SRH), measured by a simple question asking individuals to assess their overall health status, persist in the presence of an extensive set of explanatory variables. In this paper we use data from the first wave of the Los Angeles Family and Neighborhood Survey (L.A.FANS-1) to test three hypotheses regarding Hispanic-white differences in SRH. We evaluate whether poorer health reports among Hispanics result from: (1) acculturation and language-related differences in reports; (2) measures of socioeconomic status (SES) that are often omitted in other studies; and (3) somatization of emotional distress by Hispanics. Our results provide new insights into the validity of these explanations and suggest avenues for future research. First, they underscore the importance of language of interview over other measures of acculturation, suggesting that translation issues between the Spanish and English versions of the SRH question may give rise to some of the differences. Second, adjustment for SES - especially years of schooling - narrows, but does not eliminate, the gap between whites' and Hispanics' SRH. Finally, although respondents who are depressed are more likely to report poor SRH, this study provides little evidence to support the somatization hypothesis. The second wave of L.A.FANS incorporates new questions that are likely to permit more in-depth assessments of these hypotheses in future analyses.

BACKGROUND

Associations between blood pressure (BP) and ambient air pollution have been inconsistent. No studies have used ambulatory BP monitoring and outdoor home air-pollutant measurements with time-activity-location data. We address these gaps in a study of 64 elderly subjects with coronary artery disease, living in retirement communities in the Los Angeles basin.

METHODS

Subjects were followed up for 10 days with hourly waking ambulatory BP monitoring (n = 6539 total measurements), hourly electronic diaries for perceived exertion and location, and real-time activity monitors (actigraphs). We measured hourly outdoor home pollutant gases, particle number, PM2.5, organic carbon, and black carbon. Data were analyzed with mixed models controlling for temperature, posture, actigraph activity, hour, community, and season.

RESULTS

We found positive associations of systolic and diastolic BP with air pollutants. The strongest associations were with organic carbon (especially its estimated fossil-fuel- combustion fraction), multiday average exposures, and time periods when subjects were at home. An interquartile increase in 5-day average organic carbon (5.2 microg/m) was associated with 8.2 mm Hg higher mean systolic BP (95% confidence interval = 3.0-13.4) and 5.8 mm Hg higher mean diastolic BP (3.0-8.6). Associations of BP with 1-8 hour average air pollution were stronger with reports of moderate to strenuous physical exertion but not with higher actigraph motion. Associations were also stronger among 12 obese subjects.

CONCLUSIONS

Exposure to primary organic components of fossil fuel combustion near the home were strongly associated with increased ambulatory BP in a population at potential risk of heart attack. Low fitness or obesity may increase the effects of pollutants.

Methylenetetrahydrofolate reductase (MTHFR) is a key regulatory enzyme in the metabolism of folate, a nutrient that has been inversely related to colorectal cancer risk. The common C677T variant in the MTHFR gene results in a reduced activity of this enzyme, thereby increasing the availability of folate for the production of thymidylate and purine for DNA synthesis and repair. We investigated the association of the 677TT genotype with colorectal cancer in a case-control study of 822 cases and 2,021 controls nested within the Multiethnic Cohort Study. The Multiethnic Cohort Study is a large prospective study of men and women of Japanese, White, African American, Latino, and Native Hawaiian origin, residing in Hawaii and Los Angeles. After adjusting for covariates, we found an inverse association between colorectal cancer risk and the TT genotype, with odds ratios (OR; and 95% confidence intervals) for the CC, CT, and TT genotypes of 1.00, 1.01 (0.84-1.21), and 0.77 (0.58-1.03), respectively. This association was similar in both sexes, stronger at high levels of folate intake, and limited to light and nondrinkers (P for interaction with ethanol = 0.02). An analysis by subsite (rectum versus colon) and stage (regional/distant versus in situ/localized) showed that the inverse association with the TT genotype was limited to colon tumors, especially those diagnosed at an advanced stage. The OR for the TT versus CC genotype for early- and late-stage colon cancer was 0.88 (0.58-1.33) and 0.52 (0.32-0.85), respectively (P for difference in OR = 0.04). The frequency of the T allele was relatively low in African Americans (0.13) and Native Hawaiians (0.22), consistent with their greater likelihood of presenting at a late stage when diagnosed with colorectal cancer. This study corroborates previous findings of an inverse association of the MTHFR 677TT genotype with colorectal cancer, especially at high levels of folate and low levels of ethanol intake. It also suggests that this effect may be specific to advanced colon cancer.

Neonates are predisposed to infections during the perinatal period due to multiple exposures and a relatively compromised immune system. The burden of disease attributed to neonatal infections varies by geographic region and maternal and neonatal risk factors. Worldwide, it is estimated that more than 1.4 million neonatal deaths annually are the consequence of invasive infections. Risk factors for early-onset neonatal sepsis (EOS) include prematurity, immunologic immaturity, maternal Group B streptococcal colonization, prolonged rupture of membranes, and maternal intra-amniotic infection. Intrapartum antimicrobial prophylaxis administered to GBS-colonized women has reduced the burden of disease associated with early onset GBS invasive infections. Active surveillance has identified Gram-negative pathogens as an emerging etiology of early-onset invasive infections. Late-onset neonatal sepsis (LOS) attributable to Gram-positive organisms, including coagulase negative Staphylococci and Staphylococcus aureus, is associated with increased morbidity and mortality among premature infants. Invasive candidiasis is an emerging cause of late-onset sepsis, especially among infants who receive broad spectrum antimicrobial agents. Prophylactic fluconazole administration to very low birthweight (VLBW) neonates during the first 6 weeks of life reduces invasive candidiasis in neonatal intensive care units with high rates of fungal infection. Prevention of healthcare associated infections through antimicrobial stewardship, limited steroid use, early enteral feeding, limited use of invasive devices and standardization of catheter care practices, and meticulous hand hygiene are important and cost-effective strategies for reducing the burden of late-onset neonatal sepsis.

BACKGROUND

Children are an at-risk population for developing complications following influenza infection, but immunologic correlates of disease severity are not understood. We hypothesized that innate cellular immune responses at the site of infection would correlate with disease outcome.

OBJECTIVE

To test the immunologic basis of severe illness during natural influenza virus infection of children and adults at the site of infection.

METHODS

An observational cohort study with longitudinal sampling of peripheral and mucosal sites in 84 naturally influenza-infected individuals, including infants. Cellular responses, viral loads, and cytokines were quantified from nasal lavages and blood, and correlated to clinical severity.

RESULTS

We show for the first time that although viral loads in children and adults were similar, innate responses in the airways were stronger in children and varied considerably between plasma and site of infection. Adjusting for age and viral load, an innate immune profile characterized by increased nasal lavage monocyte chemotactic protein-3, IFN-α2, and plasma IL-10 levels at enrollment predicted progression to severe disease. Increased plasma IL-10, monocyte chemotactic protein-3, and IL-6 levels predicted hospitalization. This inflammatory cytokine production correlated significantly with monocyte localization from the blood to the site of infection, with conventional monocytes positively correlating with inflammation. Increased frequencies of CD14(lo) monocytes were in the airways of participants with lower inflammatory cytokine levels.

CONCLUSIONS

An innate profile was identified that correlated with disease progression independent of viral dynamics and age. The airways and blood displayed dramatically different immune profiles emphasizing the importance of cellular migration and localized immune phenotypes.

BACKGROUND

We assessed human papillomavirus (HPV) vaccine uptake among adolescent girls, parents' intentions to vaccinate daughters, and barriers and facilitators of vaccination in a population at elevated risk for cervical cancer.

METHODS

Between October 2007 and June 2008, telephone surveys were conducted with randomly selected parents/guardians of 11-18 year old girls attending public middle and high schools serving economically disadvantaged populations in Los Angeles County.

RESULTS

We surveyed 509 predominantly Hispanic (81%) and African American (16%) parents; 71% responded in Spanish. Overall, 23% reported their daughter had received ≥ 1 dose of HPV vaccine. Although 93% of daughters had seen a doctor in the past year, only 30% reported that a provider recommended HPV vaccine. Characteristics positively associated with odds of having initiated HPV vaccine were having heard of the vaccine (adjusted odds ratio [aOR] 2.6), belief in vaccine effectiveness (aOR 2.9), and doctor recommendation (aOR 48.5). Negative attitudes toward HPV vaccine (aOR 0.2) and needing more information about it (aOR 0.1) were negatively associated with vaccine initiation. Of those with unvaccinated daughters (n=387), 62% said they "probably/definitely will" vaccinate within the next year and 21% were undecided or didn't know; only 11% said they definitely won't.

CONCLUSIONS

About one-quarter of adolescent girls in this at-risk community had initiated HPV vaccine by mid-2008. Provider recommendation was the single most important factor associated with vaccination. Because a substantial proportion of parents remain undecided about HPV vaccine, health care providers can play a key role by providing needed information and offering HPV vaccine to all eligible adolescents.

Renal cell carcinoma (RCC) is the most lethal of urologic malignancies, accounting for an estimated 36,000 new cases of carcinoma and 12,000 deaths in 2005. Nephrectomy is the usual treatment; however, after nephrectomy, RCC recurs in 20% to 40% of patients with clinically localized disease. A consensus surveillance protocol does not exist for follow-up of RCC after nephrectomy. In this article, available protocols are reviewed with a goal of developing an evidence-based system including the prognostic factors for recurrent disease, chronology and sites of recurrence, available treatment options if recurrent disease is found, and modalities of diagnostic testing available to urologists. New surveillance recommendations are presented based on prognostic factors as well as the University of California, Los Angeles Integrated Staging System for RCC.

BACKGROUND

More than 3 million patients are hospitalized yearly in the United States for chest pain. The cost is over $3 billion just for those found to be free of acute disease. New rapid diagnostic tests for acute myocardial infarction (AMI) have resulted in the proliferation of accelerated diagnostic protocols (ADPs) and chest pain observation units.

OBJECTIVE

To determine whether use of an emergency department (ED)-based ADP can reduce hospital admission rate, total cost, and length of stay (LOS) for patients needing admission for evaluation of chest pain.

METHODS

Prospective randomized controlled trial comparing admission rate, total cost, and LOS for patients treated using ADP vs inpatient controls. Total costs were determined using empirically measured resource utilization and microcosting techniques.

METHODS

A large urban public teaching hospital serving a predominantly African American and Hispanic population.

METHODS

A sample of 165 patients was randomly selected from a larger consecutive sample of 429 patients with chest pain concurrently enrolled in an ADP diagnostic cohort trial. Eligible patients presented to the ED with clinical findings suggestive of AMI or acute cardiac ischemia (ACI) but at low risk using a validated predictive algorithm.

METHODS

Primary outcomes measured for each subject were LOS and total cost of treatment.

RESULTS

The hospital admission rate for ADP vs control patients was 45.2% vs 100% (P<.001). The mean total cost per patient for ADP vs control patients was $1528 vs $2095 (P<.001). The mean LOS measured in hours for ADP vs control patients was 33.1 hours vs 44.8 hours (P<.01).

CONCLUSIONS

In this trial, ADP saved $567 in total hospital costs per patient treated. Use of ED-based ADPs can reduce hospitalization rates, LOS, and total cost for low-risk patients with chest pain needing evaluation for possible AMI or ACI.

BACKGROUND

The purpose of this study was to perform a systematic review and meta-analysis of all available level I randomized controlled trials comparing single-row with double-row repair to statistically compare clinical outcomes and imaging-diagnosed re-tear rates.

METHODS

A literature search was undertaken to identify all level I randomized controlled trials comparing structural or clinical outcomes after single-row versus double-row rotator cuff repair. Clinical outcomes measures included in the meta-analysis were the American Shoulder and Elbow Surgeons, University of California-Los Angeles, and Constant scores; structural outcomes included imaging-confirmed re-tears. Meta-analyses compared raw mean differences in outcomes measures and relative risk ratios for imaging-diagnosed re-tears after single-row or double-row repairs by a random-effects model.

RESULTS

The literature search identified a total of 7 studies that were included in the meta-analysis. There were no significant differences in preoperative to postoperative change in American Shoulder and Elbow Surgeons, University of California-Los Angeles, or Constant scores between the single-row and double-row groups (P = .440, .116, and .156, respectively). The overall re-tear rate was 25.9% (68/263) in the single-row group and 14.2% (37/261) in the double-row group. There was a statistically significant increased risk of sustaining an imaging-proven re-tear of any type in the single-row group (relative risk, 1.76 [95% confidence interval, 1.25-2.48]; P = .001), with partial-thickness re-tears accounting for the majority of this difference (relative risk, 1.99 [95% confidence interval, 1.40-3.82]; P = .039).

CONCLUSIONS

Single-row repairs resulted in significantly higher re-tear rates compared with double-row repairs, especially with regard to partial-thickness re-tears. However, there were no detectable differences in improvement in outcomes scores between single-row and double-row repairs.

The incidence of neonatal late-onset sepsis (LOS) is inversely related to the degree of maturity and varies geographically from 0.61% to 14.2% among hospitalised newborns. Epidemiological data on very low birth weight infants shows that the predominant pathogens of neonatal LOS are coagulase-negative staphylococci, followed by Gram-negative bacilli and fungi. Due to the difficulties in a prompt diagnosis of LOS and LOS-associated high risk of mortality and long-term neurodevelopmental sequelae, empirical antibiotic treatment is initiated on suspicion of LOS. However, empirical therapy is often inappropriately used with unnecessary broad-spectrum antibiotics and a prolonged duration of treatment. The increasing number of multidrug-resistant Gram-negative micro-organisms in neonatal intensive care units (NICU) worldwide is a serious concern, which requires thorough and efficient surveillance strategies and appropriate treatment regimens. Immunological strategies for preventing neonatal LOS are not supported by current evidence, and approaches, such as a strict hygiene protocol and the minimisation of invasive procedures in NICUs represent the cornerstone to reduce the burden of neonatal LOS.

BACKGROUND

Men with localized prostate carcinoma are faced with important treatment decisions, and quality of life (QoL) information has become a crucial element of decision making. The first objective of this study was to compare the early, health-related QoL (HRQoL) of men with localized prostate carcinoma who were treated with radical prostatectomy, external beam radiotherapy, or brachytherapy. A second objective was to identify demographic and psychosocial variables that predict HRQoL.

METHODS

Two-hundred fifty-six men with localized prostate carcinoma were interviewed within 7 weeks of treatment initiation. The interview included measures of prostate-specific HRQoL (the University of California-Los Angeles Prostate Cancer Index), general HRQoL (the SF-36), and psychosocial variables.

RESULTS

After adjusting for covariates, treatment group differences were found for both prostate specific HRQoL and general HRQoL. Men who underwent prostatectomy reported more urinary and sexual problems and more general physical dysfunction compared with men who were treated with either form of radiation therapy. Men who were treated with brachytherapy reported the fewest problems in sexual function and the least general physical dysfunction. Few treatment group differences were found in mental functioning. Both demographic factors and psychosocial factors predicted HRQoL. Older men and African-American men reported more physical problems than younger men and Caucasian men, respectively. A supportive social environment, high self-efficacy, and high self-esteem were predictive of better HRQoL.

CONCLUSIONS

Shortly after undergoing treatment for localized prostate carcinoma, men who underwent radical prostatectomy, older men, and African-American men are at heightened risk for experiencing prostate-specific and general deficits in HRQoL. Having psychosocial resources from which to draw may enhance HRQoL.

BACKGROUND

Men with low-risk prostate cancer and significant comorbidity are susceptible to overtreatment. The authors sought to compare the impact of comorbidity and age on treatment choice in men with low-risk disease.

METHODS

The authors sampled 509 men with low-risk prostate cancer diagnosed at the Greater Los Angeles and Long Beach Veterans Affairs Medical Centers between 1997 and 2004. Rates of aggressive treatment (radical prostatectomy, radiation therapy, brachytherapy) were determined among men of different ages and with different Charlson comorbidity scores. Multivariate modeling was used to determine the influence of both variables in predicting nonaggressive treatment, and Cox proportional hazards analysis was used to compare the risk of other-cause mortality among groups according to Charlson score and age.

RESULTS

Men with Charlson scores ≥ 3 were treated aggressively in 54% of cases (30 of 56 men), while men aged >75 years at diagnosis were treated aggressively in 16% of cases (7 of 44 men). In multivariate analysis, age >75 years was a much stronger predictor of nonaggressive treatment (relative risk, 12.0; 95% confidence interval [CI], 5.4-28.3) than a Charlson score ≥ 3 (relative risk, 2.0; 95% CI, 1.3-2.9). In survival analysis, men with Charlson scores ≥ 3 had an 8-fold increased risk (hazard ratio, 8.4; 95% CI, 4.2-16.6) and 70% probability of other-cause mortality at 10 years, whereas age >75 years was associated with a 5-fold increased risk (hazard ratio, 4.9; 95%CI, 1.7-13.8) and a 24% probability of other-cause mortality.

CONCLUSIONS

Men with significant comorbidity often were overtreated for low-risk prostate cancer. Like advanced age, significant comorbidity should be a strong relative contraindication to aggressive treatment in men with low-risk disease.

OBJECTIVE

This study, using latent variable methodology, explores simultaneously the relative effects of childhood abuse and early parental substance abuse on later chronic homelessness, depression, and substance abuse problems in a sample of homeless women. We also examine whether self-esteem and recent violence can serve as mediators between the childhood predictors and the dysfunctional outcomes.

METHODS

The sample consists of 581 homeless women residing in shelters or sober living centers in Los Angeles (54% African-American, 23% Latina, 22% White, mean age=33.5 years). Multiple-indicator latent variables served as predictors and outcomes in structural models. Childhood abuse was indicated by sexual, physical, and verbal abuse.

RESULTS

Childhood abuse directly predicted later physical abuse, chronic homelessness, depression, and less self-esteem. Parent substance use directly predicted later substance use problems among the women. Recent physical abuse predicted chronic homelessness, depression, and substance use problems. Greater self-esteem predicted less depression and fewer substance use problems. Childhood abuse also had significant indirect effects on depression, chronic homelessness, and drug and alcohol problems mediated through later physical abuse and self-esteem.

CONCLUSIONS

Although there was a strong relationship between childhood abuse and parent drug use, childhood abuse was the more pervasive and devastating predictor of dysfunctional outcomes. Childhood abuse predicted a wider range of problems including lower self-esteem, more victimization, more depression, and chronic homelessness, and indirectly predicted drug and alcohol problems. The mediating roles of recent physical abuse and self-esteem suggest salient leverage points for change through empowerment training and self-esteem enhancement in homeless women.

A new dedicated PET scanner, microPET, was designed and developed at the University of California, Los Angeles, for imaging small laboratory animals. The goal was to provide a compact system with superior spatial resolution at a fraction of the cost of a clinical PET scanner.

METHODS

The system uses fiberoptic readout of individually cut lutetium oxyorthosilicate (LSO) crystals to achieve high spatial resolution. Each microPET detector consists of an 8 x 8 array of 2 x 2 x 10-mm LSO scintillation crystals that are coupled to a 64-channel photomultiplier tube by optical fibers. The tomograph consists of 30 detectors in a continuous ring with a 17.2-cm diameter and fields of view (FOVs) of 11.25 cm in the transaxial direction and 1.8 cm in the axial direction. The system has eight crystal rings and no interplane septa. It operates exclusively in the three-dimensional mode and has an electronically controlled bed that is capable of wobbling with a radius of 300 microm. We describe the performance of the tomograph in terms of its spatial, energy and timing resolution, as well as its sensitivity and counting-rate performance. We also illustrate its overall imaging performance with phantom and animal studies that demonstrate the potential applications of this device to biomedical research.

RESULTS

Images reconstructed with three-dimensional filtered backprojection show a spatial resolution of 1.8 mm at the center of the FOV (CFOV), which remains <2.5 mm for the central 5 cm of the transaxial FOV. The resulting volumetric resolution of the system is <8 microL. The absolute system sensitivity measured with a 0.74 MBq (20 microCi) 68Ge point source at the CFOV is 5.62 Hz/kBq. The maximum noise equivalent counting rate obtained with a 6.4-cm diameter cylinder spanning the central 56% of the FOV is 10 kcps, whereas the scatter fraction is 37% at the CFOV for an energy window of 250-650 keV and the same diameter cylinder.

CONCLUSIONS

This is the first PET scanner to use the new scintillator LSO and uses a novel detector design to achieve high volumetric spatial resolution. The combination of imaging characteristics of this prototype system (resolution, sensitivity, counting-rate performance and scatter fraction) opens up new possibilities in the study of animal models with PET.

BACKGROUND

Trypanosoma cruzi, the agent of Chagas' disease, continues to be a concern for blood safety, as demonstrated by recent transfusion-transmitted cases in the United States and Canada. The chronic nature of Chagas', coupled with increasing numbers of immigrants from T. cruzi-endemic countries, suggests that Chagas' is a long-term public health problem. Herein, we report on a multiyear epidemiologic study of T. cruzi in Los Angeles and Miami blood donors.

METHODS

From May 1994 to September 1998, blood donors in Los Angeles and Miami were queried regarding birth or time spent in an endemic country. Donations of "yes" respondents were tested by EIA, confirmed by radioimmunoprecipitation assay, and if confirmed as seropositive, enrolled in look-back investigations.

RESULTS

A total of 1,104,030 Los Angeles and 181,139 Miami donors were queried regarding risk; 7.3 and 14.3 percent, respectively, responded yes. Seropositive rates were 1 in 7,500 Los Angeles and 1 in 9,000 Miami donors. In Los Angeles, seroprevalence rates increased significantly from 1996 to 1998 and were significantly higher for directed donors than nondirected donors. Look back identified 18 recipients, all of whom were seronegative for T. cruzi.

CONCLUSIONS

Significant numbers of T. cruzi-seropositive donors contribute to the U.S. blood supply. The incidence of seropositivity is enhanced by minority recruitment efforts necessitated by donor demographic shifts. Similarly, high rates among directed donations in Los Angeles are attributable to a disproportionate number of at-risk directed donors. Current look-back data likely underestimate the frequency of transfusion- transmitted T. cruzi. These results indicate that continued evaluation of transfusion as a mode of T. cruzi transmission in the United States is needed.

The enzyme 5-lipoxygenase (5-LO) catalyzes the first two reactions in the pathway leading to the formation of leukotrienes from arachidonic acid. Leukotrienes are potent arachidonic acid metabolites possessing biological activities that suggest a role in the pathophysiology of allergic and inflammatory diseases. To obtain structural information about 5-LO for use in developing anti-inflammatory chemotherapeutic agents, the enzyme was purified from human polymorphonuclear leukocytes and the amino acid sequences were determined for several cyanogen bromide-derived peptides. A cDNA clone encoding a 674-amino acid protein containing all of the derived peptide sequences was isolated from a dimethyl sulfoxide differentiated HL60 cell cDNA library. The mRNA encoding 5-LO was detected only in differentiated HL60 cells and not in the undifferentiated cell line, indicating that the expression of 5-LO in this cell line is transcriptionally regulated. In addition, the human protein displays some amino acid sequence homology with several lipases and significant homology with the partial sequences of soybean and reticulocyte lipoxygenases. Thus, 5-LO appears to be a member of a larger family of related enzymes.

Lessons from the sweat gland on cystic fibrosis (CF) began long before modern medicine became a science. In European folklore, the curse that "a child that taste salty when kissed will soon die" (Alonso y de los Ruyzes de Fonteca J. Diez Previlegios para Mugeres Prenadas. Henares, Spain, 1606) has been taken by many as a direct reference to cystic fibrosis [Busch R. Acta Univ Carol Med (Praha) 36: 13-15, 1990]. The high salt concentration in sweat from patients with CF is now accepted as almost pathognomonic with this fatal genetic disease, but the earliest descriptions of cystic fibrosis as a disease entity did not mention sweat or sweat glands (Andersen DH. Am J Dis Child 56: 344-399, 1938; Andersen DH, Hodges RG. Am J Dis Child 72: 62-80, 1946). Nonetheless, defective sweating soon became an inseparable, and major, component of the constellation of symptoms that diagnose "cystic fibrosis" (Davis PB. Am J Respir Crit Care Med 173: 475-482, 2006). The sweat gland has played a foremost role in diagnosing, defining pathophysiology, debunking misconceptions, and increasing our understanding of the effects of the disease on organs, tissues, cells, and molecules. The sweat gland has taught us much.

The recent description of a Lin(-)AA4.1(+)CD19(+)B220(Lo/-) B1-specified progenitor (B1P) population in adult marrow adds support for the argument that these unique B cells arise from a distinct lineage. However, the origins of B1P were not investigated and their developmental relationships to conventional B2 cells remain unclear. We now report that B1P development is IL-7Ralpha-dependent, and negatively regulated by Bruton tyrosine kinase. Lymphoid characteristics of B1P were further studied with recombination activating gene (RAG)-1/GFP knock-in, RAG-1/Cre reporter, and VEX transgenic mice. Our results reveal that they are heterogeneous with respect to lymphocyte affiliation. RAG-1(+) early lymphoid progenitors and Lin(-)Sca-1(+)cKit(Lo)IL-7Ralpha(+) common lymphoid progenitors from adult marrow efficiently generated CD19(+)CD45R/B220(Lo/-) cells in vitro and in vivo. Moreover, early lymphoid progenitors and common lymphoid progenitors produced significant numbers of peritoneal CD11b(+)CD5(+) B1a and CD11b(+)CD5(-) B1b cells in vivo. Finally, 2-step transplantation experiments established a differentiation pathway between conventional lymphoid progenitors, B1P, and mature B1 lymphocytes. Thus, our findings indicate that at least some B1P can be produced in adult bone marrow from primitive B2 progenitors, and suggest a developmental relationship between the major categories of B lymphocytes.

Understanding the phase behavior of biological membranes is helped by the study of more simple systems. Model membranes that have as few as 3 components exhibit complex phase behavior that can be well described, providing insight for biological membranes. A number of different studies are in agreement on general findings for some compositional phase diagrams, in particular, those that model the outer leaflet of animal cell plasma membranes. These model mixtures include cholesterol, together with one high-melting lipid and one low-melting lipid. An interesting finding is of two categories of such 3-component mixtures, leading to what we term Type I and Type II compositional phase diagrams. The latter have phase regions of macroscopic coexisting domains of [Lalpha+Lbeta+Lo] and of [Lalpha+Lo], with domains resolved under the light microscope. Type I mixtures have the same phase coexistence regions, but the domains seem to be nanoscopic. Type I mixtures are likely to be better models for biological membranes.

OBJECTIVE

Nutritional support as enteral or parenteral nutrition (PN) is used in hospitalized patients to reduce catabolism. This study compares outcomes of early enteral nutrition (EN) with early PN in hospitalized patients.

METHODS

The authors conducted a metaanalysis of randomized, controlled trials (RCT) comparing early EN with PN. Studies on immunonutrition were excluded. Studies were categorized as medical, surgical, or trauma.

METHODS

RCTs of early EN/PN were identified by search of 1) MEDLINE (1966-2002), 2) published abstracts from scientific meetings, and 3) bibliographies of relevant articles.

RESULTS

Thirty RCTs (ten medical, 11 surgical, and nine trauma) compared early EN with PN. The effect of nutrition type on hospital mortality and complication rates was reported as risk difference (RD%) and hospital length of stay (LOS) as mean weighted difference (MWD days). Missing data, by outcomes, varied from 20% to 63%. As a result of heterogeneity of treatment effects, the DerSimonian-Laird random-effects estimator was reported. There was no differential treatment effect of nutrition type on hospital mortality for all patients (0.6%, p = .4) and subgroups. PN was associated with increases in infective complications (7.9%, p = .001), catheter-related blood stream infections (3.5%, p = .003), noninfective complications (4.9%, p = .04), and hospital LOS (1.2 days, p = .004). There was no effect of nutrition type on technical complications (4.1%, p = .2). EN was associated with a significant increase in diarrheal episodes (8.7%, p = .001). Publication bias was not demonstrated. Metaanalytic regression analysis did not demonstrate any effect of age, time to initiate treatment, and average albumin on mortality estimates. Cumulative metaanalysis showed no change in the mortality estimates with time.

CONCLUSIONS

There was no mortality effect with the type of nutritional supplementation. Although early EN significantly reduced complication rates, this needs to be interpreted in the light of missing data and heterogeneity. The enthusiasm that early EN, as compared with early PN, would reduce mortality appears misplaced.

Poisson regression models were used to evaluate associations between temperature, precipitation, days of extreme heat, and other weather changes (lagged 7 days), as well as El Niño events, with hospitalizations for acute myocardial infarction, angina pectoris, congestive heart failure, and stroke in three California regions. Temperature changes were defined as a 3 degrees C decrease in maximum temperature or a 3 degrees C increase in minimum temperature. Temperature and precipitation were analyzed separately for normal weather periods and El Niño events, and for both weather periods combined. Associations varied by region, age, and gender. In Los Angeles, temperature changes resulted in small changes in hospitalizations. Among San Francisco residents 70+ years of age, temperature changes increased hospitalizations for nearly all outcomes from 6% to 13%. Associations among Sacramento residents were similar to those in San Francisco: among men 70+ years of age, temperature changes increased hospitalizations by 6%-11% for acute myocardial infarction and congestive heart failure, and 10%-18% for stroke. El Niño events were consistently and significantly associated with hospitalizations only in San Francisco and Sacramento, and then only for angina pectoris (increasing hospitalizations during El Niño events). These exploratory analyses merit further confirmation to improve our understanding of how admissions to hospitals for cardiovascular disease and stroke change with changing weather. Such an understanding is useful for developing current public health responses, for evaluating population vulnerability, and for designing future adaptation measures.