Th17 cytokines interleukin (IL)-17 and IL-22 modulate distinct inflammatory and keratinocyte-response pathways

BACKGROUND

Psoriasis vulgaris is an inflammatory skin disease mediated by Th1 and Th17 cytokines, yet the relative contribution of interferon (IFN)-gamma, interleukin (IL)-17 and IL-22 on disease pathogenesis is still unknown.

OBJECTIVES

In this study, we sought to identify the cytokines produced by skin-resident T cells in normal skin, localize the receptors for these cytokines, and examine how these cytokines alter gene expression profiles of the cells bearing cognate receptors.

METHODS

We used intracellular cytokine staining and flow cytometry to evaluate T cell cytokine production, and immunohistochemistry and double-label immunofluorescence to localize cytokine receptors in skin. Gene array analysis of cytokine-treated keratinocytes was performed using moderated paired t-test controlling for false discovery rate using the Benjamini-Hochberg procedure.

RESULTS

We demonstrate that T-helper cells producing IL-17, IL-22 and/or IFN-gamma, as well as the cells bearing cognate cytokine receptors, are present in normal human skin. Keratinocytes stimulated with IL-17 expressed chemokines that were different from those induced by IFN-gamma, probably contributing to the influx of neutrophils, dendritic cells and memory T cells into the psoriatic lesion. In contrast, IL-22 downregulated genes associated with keratinocyte differentiation and caused epidermal alterations in an organotypic skin model.

CONCLUSIONS

Our results suggest that the Th17 cytokines IL-17 and IL-22 mediate distinct downstream pathways that contribute to the psoriatic phenotype: IL-17 is more proinflammatory, while IL-22 retards keratinocyte differentiation.

Ventilator-associated pneumonia by Staphylococcus aureus. Comparison of methicillin-resistant and methicillin-sensitive episodes

All episodes of ventilator-associated pneumonia (VAP) caused by Staphylococcus aureus were prospectively analyzed for a 30-mo period. Methicillin-sensitive S. aureus (MSSA) was isolated in 38 episodes and methicillin-resistant S. aureus (MRSA) in 11 others. The two groups were similar regarding sex, severity of underlying diseases, prior surgery, and presence of renal failure, diabetes, cardiopathy, and coma. MRSA-infected persons were more likely to have received steroids before developing infection (relative risk [RR] = 3.45, 95% confidence interval [CI] = 1.38-8.59), to have been ventilated > 6 d (RR = 2.03, 95% CI = 1.36-3.03), to have been older than 25 yr (RR = 1.50, 95% CI = 1.09-2.06), and to have had preceding chronic obstructive pulmonary disease (RR = 2.76, 95% CI = 0.89-8.56) than MSSA-infected patients. MSSA-infected persons were more likely than MRSA-infected patients to have cranioencephalic trauma (RR = 1.94, 95% CI = 1.22-3.09). All patients with MRSA VAP had previously received antibiotics, compared with only 21.1% of those with MSSA infection (p < 0.000001). The incidence of empyema was similar in both groups; nevertheless, the presence of bacteremia and septic shock was more frequent in the MRSA group. Finally, mortality directly related to pneumonia was significantly higher among patients with MRSA episodes (RR = 20.72, 95% CI = 2.78-154.35). This analysis was repeated for monomicrobial episodes, and the difference remained statistically significant. We conclude that MRSA and MSSA strains infect patients with different demographic profiles; previous antibiotic therapy is the most important risk factor for developing MRSA infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Successful treatment of active ankylosing spondylitis with the anti-tumor necrosis factor alpha monoclonal antibody infliximab

OBJECTIVE

Tumor necrosis factor alpha (TNFalpha) has been detected in sacroiliac joint biopsy specimens from patients with spondylarthropathy. The present open pilot study was undertaken to test the efficacy of the anti-TNFalpha monoclonal antibody infliximab in the treatment of active ankylosing spondylitis (AS).

METHODS

Eleven patients with AS of short duration (median 5 years, range 0.5-13 years) that had been active for at least 3 months (range 3-72 months) were treated with 3 infusions of infliximab (at weeks 0, 2, and 6), in a dosage of 5 mg/kg. Ten of the 11 patients had elevated C-reactive protein (CRP) levels (>6 mg/liter) before treatment; these elevations were known to have had persisted > 1 year in at least 3 patients. The Bath AS Disease Activity Index (BASDAI), the Bath AS Functional Index (BASFI), pain as measured on a visual analog scale, and the Bath AS Metrology Index (BASMI) were assessed. Quality of life was assessed using the Short Form 36 instrument. Laboratory markers of disease activity, including interleukin-6 (IL-6) levels, were determined. Dynamic magnetic resonance imaging (MRI) of the spine was performed in 5 patients.

RESULTS

One patient withdrew from the study due to the occurrence of urticarial xanthoma 8 days after the first infusion. At study enrollment, 3 of 5 patients had evidence of spinal inflammation (spondylitis and spondylodiscitis) as detected by MRI; followup MRI 2-6 weeks after the third infusion revealed improvement in 2. Improvement of > or = 50% in activity, function, and pain scores was documented in 9 of 10 patients; the median improvement in the BASDAI after 4 weeks was 70% (range 41-94%). This clear-cut benefit lasted for 6 weeks after the third infusion in 8 of 10 patients. The median CRP level decreased from 15.5 mg/liter (range <6-90.8) to normal, and the median IL-6 level from 12.4 mg/liter (range 0-28.4) to normal (<5). There was improvement in all 9 SF-36 concepts; the improvement was significant for 6 concepts.

CONCLUSION

These data suggest that anti-TNFalpha therapy is very effective for several weeks in AS. Whether this therapy, in addition to its antiinflammatory effect, prevents ankylosis remains to be determined.

Bronchial microbial patterns in severe exacerbations of chronic obstructive pulmonary disease (COPD) requiring mechanical ventilation

We carried out a comprehensive microbiological study of the upper and lower airways in patients with severe exacerbations of chronic obstructive pulmonary disease (COPD) requiring mechanical ventilation in order to describe microbial patterns and analyze their clinical significance. Quantitative cultures of tracheobronchial aspirates (TBAs), bronchoscopically retrieved protected specimen brush (PSB) and bronchoalveolar lavage fluid (BALF) at admission to the ICU and after 72 h, as well as serology for bacteria and respiratory viruses were performed. Fifty patients (mean age 68 +/- 8, 46 males) were studied prospectively. Potentially pathogenic microorganisms (PPMs) and/or a positive serology were present in 36 of 50 (72%) patients, including 12 (33%) polymicrobial cases. Only six (12%) had no pathogen in any sample in the absence of antimicrobial pretreatment. Microbial patterns corresponded to community-acquired pathogens (Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis) in 19 of 34 (56%) and to gram-negative enteric bacilli (GNEB), Pseudomonas, and Stenotrophomonas spp. in 15 of 34 (44%) of isolates. Chlamydia pneumoniae and respiratory viruses were found in 18% and 16% of investigations, respectively. Repeated investigation after 72 h in 19 patients with PPMs in the initial investigation revealed eradication of virtually all isolates of community-acquired pathogens and GNEB but persistence of three of five Pseudomonas spp. and both Stenotrophomonas spp. as well as the emergence of new GNEB, Pseudomonas and Stenotrophomonas spp. Clinical parameters neither predicted the presence of PPMs nor of GNEB and Pseudomonas/Stenotrophomonas spp. Nevertheless, severe pneumonia attributable to initially isolated pathogens occurred in two patients with severe COPD exacerbation. We conclude that pathogens were more frequently present than previously reported. The rate of GNEB and Pseudomonas/Stenotrophomonas spp. isolates was high. The presence of pathogens was clinically unpredictable. Thus, in this population of patients with severe exacerbations of COPD, it may be advisable to obtain respiratory samples and to treat according to diagnostic results. Further studies are warranted to clarify this issue.

Fatigue in rheumatoid arthritis reflects pain, not disease activity

OBJECTIVE

We determined the amount of fatigue experienced by patients with RA, and its relationship to synovitis, pain and other common clinical features. We also examined to what extent RA fatigue is improved by disease-modifying antirheumatic drugs (DMARDs) and anti-tumour necrosis factor (TNF) therapy.

METHODS

We studied two cohorts of 238 and 274 RA patients cross-sectionally and examined treatment responses in 30 RA patients starting anti-TNF and 54 starting DMARDs followed for 3 and 6 months. We measured fatigue using visual analogue scores (VAS) and Medical Outcomes Study Short Form 36 (SF-36) vitality scores. We recorded the disease activity score for 28 joints and its components (tender/swollen joint counts, patient global assessment, ESR), morning stiffness, health assessment questionnaire, physician global assessment, erosive disease, nodules, rheumatoid factor, concomitant medications and illnesses, and the SF-36 questionnaire.

RESULTS

Fatigue was common in RA patients; over 80% had clinically relevant fatigue (VAS > or =20 mm), over 50% had high levels (VAS > or =50 mm). It was associated with pain and changes in mental health, particularly depression. In each of the two cross-sectional cohorts, this relationship was similar whichever measures of fatigue and mental health were used. Fatigue fell with DMARDs and anti-TNF: before treatment, 87% of patients had high fatigue, after treatment this fell to 50%. These treatment effects were mainly linked to improvements in pain.

CONCLUSIONS

High fatigue levels characterize RA and are mainly linked to pain and depression. The association with disease activity is secondary. Fatigue falls with DMARD and anti-TNF therapy. The balance of evidence suggests that fatigue is centrally mediated in established RA.

Airway inflammation and bronchial microbial patterns in patients with stable chronic obstructive pulmonary disease

The effect of bacterial colonization of the bronchi on the progress of airflow limitation is not well known. Therefore, the pattern of airway inflammation in smokers and patients with stable chronic obstructive pulmonary disease (COPD) and its relation to bronchial microbial colonization was assessed. Eight nonsmoking and 18 smoking controls as well as 52 patients with COPD (28 mild, 11 moderate and 13 severe) were studied. All subjects were investigated by means of flexible bronchoscopy including protected specimen brush and bronchoalveolar lavage (BAL) sampling. Differential cell counts, cytokine (interleukin (IL)-1beta, IL-6, IL-8, IL-10 and tumour necrosis factor-alpha(TNF-alpha) concentrations and microbial patterns were determined in BAL fluid. Forced expiratory volume in one second (FEV1) % of the predicted value was inversely correlated with pack-yrs of cigarette smoking (r=-0.47, p<0.0001), the percentage of neutrophil (p=-0.56, p<0.0001) and IL-6 (p=-0.37, p=0.01) and IL-8 concentration (p=-0.43, p=0.004) in BAL fluid. Accordingly, pk-yrs of cigarette smoking (p=0.39, p=0.01) and IL-8 (p=0.69, p<0.0001) and TNFalpha (p=0.4, p<0.005) were positively correlated with the percentage of neutrophils in BAL fluid. Smoking controls and COPD patients were mainly colonized in the bronchial tree (33%) by community endogenous potentially pathogenic micro-organisms (PPMs). Colonization rates and patterns of PPMs were not affected by severity of airflow obstruction. The presence of PPMs was significantly associated with higher percentages of neutrophils (33.2+/-10.4% versus 10.1+/-3.5%, p=0.02) and TNF-alpha concentration (29.9+/-10.8 versus 6.3+/-2.1 pg x mL(-1), p=0.01) in BAL fluid. In conclusion, bronchial neutrophilia is a key inflammatory pattern in chronic obstructive pulmonary disease patients. Bronchial colonization with potentially pathogenic micro-organisms may represent an independent stimulus for additional airway inflammation.

Long-term angiographic and clinical outcome after percutaneous transluminal coronary angioplasty and intracoronary radiation therapy in humans

BACKGROUND

Ionizing radiation has been shown to reduce neointimal formation after balloon angioplasty in experimental models of restenosis. This study was designed to evaluate the feasibility, safety, and effectiveness of intracoronary radiation therapy (ICRT) after percutaneous transluminal coronary angioplasty (PTCA) for preventing restenosis in human coronary arteries.

METHODS AND RESULTS

Twenty-one patients (22 arteries) with unstable angina underwent standard balloon angioplasty. ICRT was performed with the use of an 192Ir source wire that was hand delivered to the angioplasty site. Angiographic follow-up was performed at 24 hours, between 30 and 60 days, and at 6 months. Angioplasty was successful in 19 of 22 lesions, and insertion of the radioactive source wire was successful at all treated sites. Angiographic study at 24 hours demonstrated early late loss of the luminal diameter from 1.92+/-0.55 to 1.40+/-0.27 mm. Between 30 and 60 days, repeat angiography demonstrated total occlusion in 2 arteries, a new pseudoaneurysm in 1 artery, and significant dilatation at the treatment site in 2 additional vessels. At > or = 6 months' follow-up, all remaining arteries (n=20) maintained patent, with a mean lumen diameter of 1.65+/-0.8 mm. The calculated late lumen loss was 0.27+/-0.56 mm, and the late loss index was 0.19. Clinical events at 1 year included myocardial infarction in 1 patient, repeat angioplasty to the treated site in 3 patients, and persistent angina in 7 patients.

CONCLUSIONS

These preliminary results demonstrate that ICRT after coronary intervention is feasible and is associated with an acceptable degree of complications and lower rates of angiographic restenosis indexes.

Extracellular Tau Oligomers Produce An Immediate Impairment of LTP and Memory

Non-fibrillar soluble oligomeric forms of amyloid-β peptide (oAβ) and tau proteins are likely to play a major role in Alzheimer's disease (AD). The prevailing hypothesis on the disease etiopathogenesis is that oAβ initiates tau pathology that slowly spreads throughout the medial temporal cortex and neocortices independently of Aβ, eventually leading to memory loss. Here we show that a brief exposure to extracellular recombinant human tau oligomers (oTau), but not monomers, produces an impairment of long-term potentiation (LTP) and memory, independent of the presence of high oAβ levels. The impairment is immediate as it raises as soon as 20 min after exposure to the oligomers. These effects are reproduced either by oTau extracted from AD human specimens, or naturally produced in mice overexpressing human tau. Finally, we found that oTau could also act in combination with oAβ to produce these effects, as sub-toxic doses of the two peptides combined lead to LTP and memory impairment. These findings provide a novel view of the effects of tau and Aβ on memory loss, offering new therapeutic opportunities in the therapy of AD and other neurodegenerative diseases associated with Aβ and tau pathology.

Results of screening 1.9 million Texas newborns for 21-hydroxylase-deficient congenital adrenal hyperplasia

OBJECTIVE

To assess results of newborn screening for 21-hydroxylase-deficient congenital adrenal hyperplasia (CAH) in Texas over 6 years of screening 1.9 million infants.

METHODS

In 1989, CAH was incorporated into the ongoing Texas Newborn Screening Program, which requires two screens on each newborn. 17-Hydroxyprogesterone was assayed, without extraction, by radioimmunoassay of blood collected from heel sticks onto filter paper collection cards. Infants with elevated levels of 17-hydroxyprogesterone were referred for evaluation, and those considered to have CAH were studied with respect to disease characteristics. Data were collected by pediatric endocrinologists using standardized forms that included type of CAH, results of laboratory tests, treatment regimen, disease symptoms and signs, and, for girls, degree of genital virilization.

RESULTS

The incidence of classic CAH in Texas is 1:16 008, with a ratio of salt-wasting to simple-virilizing of 2.7:1. A majority of infants detected were undiagnosed until screened, despite signs of salt-wasting or ambiguous genitalia. It was difficult to differentiate salt-wasting from simple-virilizing CAH in infants who were identified before the onset of adrenal insufficiency or electrolyte abnormalities. A substantial number of infants with nonclassic (NC) CAH also were detected. Not all infants were detected on the initial screen; 14% of infants with classic CAH and 87% with NC CAH were detected on the second routine screening test.

CONCLUSIONS

Our findings confirm the benefits of newborn screening for CAH and the importance of a second screening test, and suggest that programs for newborn CAH screening must consider complex issues in diagnosis and treatment. These results also confirm that CAH is a continuum of disorders, rather than a disorder with discrete subtypes. In addition, the difficulties in differentiating CAH subtypes in newborns, and thus deciding appropriate treatment, and the high incidence of NC CAH suggest that standard diagnostic criteria and treatment regimens for CAH may need modification. Where screening exists, physicians will encounter more cases of CAH than in the past.

Bacterial colonisation in patients with bronchiectasis: microbiological pattern and risk factors

BACKGROUND

A study was undertaken to investigate the incidence, diagnostic yield of non-invasive and bronchoscopic techniques, and risk factors of airway colonisation in patients with bronchiectasis in a stable clinical situation.

METHODS

A 2 year prospective study of 77 patients with bronchiectasis in a stable clinical condition was performed in an 800 bed tertiary university hospital. The interventions used were pharyngeal swabs, sputum cultures and quantitative protected specimen brush (PSB) bacterial cultures (cut off point > or =10(2) cfu/ml) and bronchoalveolar lavage (BAL) (cut off point > or =10(3) cfu/ml).

RESULTS

The incidence of bronchial colonisation with potential pathogenic microorganisms (PPMs) was 64%. The most frequent PPMs isolated were Haemophilus influenzae (55%) and Pseudomonas spp (26%). Resistance to antibiotics was found in 30% of the isolated pathogens. When the sample was appropriate, the operative characteristics of the sputum cultures were similar to those obtained with the PSB taken as a gold standard. Risk factors associated with bronchial colonisation by PPMs in the multivariate analysis were: (1) diagnosis of bronchiectasis before the age of 14 years (odds ratio (OR)=3.92, 95% CI 1.29 to 11.95), (2) forced expiratory volume in 1 second (FEV1) <80% predicted (OR=3.91, 95% CI 1.30 to 11.78), and (3) presence of varicose or cystic bronchiectasis (OR=4.80, 95% CI 1.11 to 21.46).

CONCLUSIONS

Clinically stable patients with bronchiectasis have a high prevalence of bronchial colonisation by PPMs. Sputum culture is a good alternative to bronchoscopic procedures for evaluation of this colonisation. Early diagnosis of bronchiectasis, presence of varicose-cystic bronchiectasis, and FEV1 <80% predicted appear to be risk factors for bronchial colonisation with PPMs.

TMEM106B regulates progranulin levels and the penetrance of FTLD in GRN mutation carriers

OBJECTIVES

To determine whether TMEM106B single nucleotide polymorphisms (SNPs) are associated with frontotemporal lobar degeneration (FTLD) in patients with and without mutations in progranulin (GRN) and to determine whether TMEM106B modulates GRN expression.

METHODS

We performed a case-control study of 3 SNPs in TMEM106B in 482 patients with clinical and 80 patients with pathologic FTLD-TAR DNA-binding protein 43 without GRN mutations, 78 patients with FTLD with GRN mutations, and 822 controls. Association analysis of TMEM106B with GRN plasma levels was performed in 1,013 controls and TMEM106B and GRN mRNA expression levels were correlated in peripheral blood samples from 33 patients with FTLD and 150 controls.

RESULTS

In our complete FTLD patient cohort, nominal significance was identified for 2 TMEM106B SNPs (top SNP rs1990622, p(allelic) = 0.036). However, the most significant association with risk of FTLD was observed in the subgroup of GRN mutation carriers compared to controls (corrected p(allelic) = 0.0009), where there was a highly significant decrease in the frequency of homozygote carriers of the minor alleles of all TMEM106B SNPs (top SNP rs1990622, CC genotype frequency 2.6% vs 19.1%, corrected p(recessive) = 0.009). We further identified a significant association of TMEM106B SNPs with plasma GRN levels in controls (top SNP rs1990622, corrected p = 0.002) and in peripheral blood samples a highly significant correlation was observed between TMEM106B and GRN mRNA expression in patients with FTLD (r = -0.63, p = 7.7 × 10(-5)) and controls (r = -0.49, p = 2.2 × 10(-10)).

CONCLUSIONS

In our study, TMEM106B SNPs significantly reduced the disease penetrance in patients with GRN mutations, potentially by modulating GRN levels. These findings hold promise for the development of future protective therapies for FTLD.

Naltrexone. A review of its pharmacodynamic and pharmacokinetic properties and therapeutic efficacy in the management of opioid dependence

Naltrexone is a long acting competitive antagonist at opioid receptors which blocks the subjective and objective responses produced by intravenous opioid challenge. It is suitable for oral administration, and has been studied as an adjunct for use in opioid addiction management programmes. In non-comparative clinical trials involving detoxified patients, oral naltrexone reduced heroin craving and between 23 and 62% of patients remained in treatment after 3 to 4 weeks. However, in two studies 32 to 58% of patients who continued in treatment were opioid-free between 6 and 12 months after stopping naltrexone. As might be expected studies involving highly motivated patients have shown this type of patient group to achieve greater treatment success rates during naltrexone therapy, and remain opioid-free longer than other groups of apparently less motivated patients. In addition, when naltrexone is combined with family support, psychotherapy and counselling, patients are more likely to remain opioid-free. Naltrexone produces a low incidence of side effects, with gastrointestinal effects being the most commonly reported symptoms. Thus, despite the overall high attrition rates from trials, in selected patient groups and in combination with appropriate support mechanisms and psychotherapy, naltrexone represents a useful adjunct for the maintenance of abstinence in the detoxified opioid addict.

Validation of different techniques for the diagnosis of ventilator-associated pneumonia. Comparison with immediate postmortem pulmonary biopsy

To assess the accuracy of clinical parameters for the diagnosis of ventilator-associated (VA) pneumonia, as well as the diagnostic value of several invasive techniques, such as protected specimen brush (PSB), bronchoalveolar lavage (BAL), fiberoptic bronchial aspirates (FBAS), and percutaneous lung needle aspiration (PLNA), we compared the results of these techniques with the histopathology of immediate postmortem pulmonary biopsies, considered the "gold standard" reference test. We studied 30 mechanically ventilated patients (age 52 +/- 21 yr; mechanical ventilation period 9 +/- 7 days) who died in an intensive care unit. All patients received prior antibiotic treatment. The following procedures were performed immediately after death: bilateral PSB, BAL, FBAS, and PLNA, as well as bilateral minithoracotomies to obtain pulmonary biopsies as close as possible to the area sampled with the other techniques. According to the histopathology 18 patients had pneumonia and 12 did not. The presence of fever (sensitivity 55%, specificity 58%), purulent secretions (sensitivity 83%, specificity 33%), and chest radiograph infiltrates (sensitivity 78%, specificity 42%) could not differentiate in all instances presence from absence of pneumonia. Quantitative bacterial cultures of lung biopsies using 10(3) cfu/g as a cutoff point had low sensitivity (40%) and low specificity (45%) and could not differentiate the histologic absence or presence of pneumonia. Considering the histopathology of pulmonary biopsies as a gold standard, we found the following sensitivities for PSB, BAL, FBAS, and PLNA: 36, 50, 44, and 25%. The specificities were 50, 45, 48, and 79%, respectively. The sensitivities and specificities of different invasive techniques are much lower than those reported in clinical studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Nutritional assessment with bioelectrical impedance analysis in maintenance hemodialysis patients

Protein energy malnutrition is common among persons with ESRD and contributes substantially to morbidity and mortality. The usual methods of nutritional assessment, such as anthropometry, can be misleading because of altered tissue hydration. Bioelectrical impedance analysis (BIA) has been recommended by some as a practical nutritional assessment tool but has not been validated in patients with ESRD. Thirty-three stable patients on maintenance hemodialysis were evaluated in an ambulatory clinical research center with simultaneous BIA, dual-energy x-ray absorptiometry, and deuterium oxide (D2O) and sodium bromide (NaBr) isotope dilution studies. Standard determinations of total body water (TBW) and body cell mass (BCM) were obtained and compared with values estimated by BIA. Two separate outpatient BIA measurements were also obtained approximately 2 wk before and after the clinical research center evaluation. BCM estimated by BIA was directly correlated (r = 0.92, P < 0.0001) with BCM determined by DEXA and NaBr. TBW estimated by BIA was directly correlated (r = 0.96, P < 0.0001) with TBW determined by deuterium oxide dilution. The reactance to resistance ratio (Xc/R) derived from BIA was inversely correlated (r = -0.73, P < 0.0001) with the extracellular water/TBW ratio determined by NaBr/D2O. Bland-Altman analyses showed that for TBW, BIA was in excellent agreement with D2O dilution. BCM was modestly underestimated by BIA compared with the dual-energy x-ray absorptiometry/NaBr standard and was adjusted by linear regression. The coefficients of variation on repeated BIA measurements were below 4%, demonstrating test-retest reliability. BIA is a valid and reliable method of nutritional assessment in maintenance hemodialysis patients.

Diagnostic value of quantitative cultures of bronchoalveolar lavage and telescoping plugged catheters in mechanically ventilated patients with bacterial pneumonia

We compared the diagnostic value of quantitative cultures of bronchoalveolar lavage (BAL) and telescoping plugged catheter (TPC) samples in 34 nonimmunocompromised, mechanically ventilated (MV) patients with suspected bacterial pneumonia. A control group of seven "noninfected" MV patients was also studied. In 92% of patients with bacterial pneumonia (32 of 34), simple endotracheal aspiration samples recovered one or more microorganisms. Both BAL and TPC samples cultured colony-forming units (cfu) greater than or equal to 10(3)/ml of one or more microorganisms in 56% (19 of 34) of patients. TPC and BAL culture results agreed on 88.5% (54 of 61) of the recovered microorganisms. Sterile TPC and BAL cultures agreed on 80% (4 of 5) of the cases. Microorganisms cultured from blood samples were also cultured from BAL and TPC specimens. Culture results from the two techniques completely disagreed in only one case (3%). In the control group, one TPC and two BAL cultures yielded microorganisms in cfu greater than or equal to 10(3)/ml. Specificities of BAL and TPC were 71 and 86%, respectively, whereas specificity of endotracheal aspiration was only 14%. Both the bacterial index obtained by TPC and BAL, as well as the quantitative cultures, correlated moderately well (r = 0.78 and 0.72, respectively, p less than 0.001 for both correlations). BAL and TPC results caused changes of antibiotic treatment in 11 of 23 survivors. Neither BAL nor TPC caused complications. Our results demonstrate that BAL and TPC diagnose bacterial pneumonia in MV patients with similar accuracy. Culture results from both techniques showed excellent qualitative and reasonable quantitative agreement.

Deficient lower-segment Cesarean section scars: prevalence and risk factors

OBJECTIVE

To examine the sonographic features of transverse lower-segment uterine Cesarean section scars in non-pregnant, premenopausal women and to identify factors associated with scar deficiency.

METHODS

Non-pregnant, premenopausal women with histories of previous transverse lower-segment Cesarean sections, who were referred for an ultrasound scan for a variety of gynecological indications, were included in this study. An attempt was made to identify the uterine scars on transvaginal ultrasound scan and to describe their locations and morphological features. Various demographic, clinical and ultrasound data were examined in order to identify factors associated with deficient scars. Deficient scars were defined as detectable myometrial thinning at the site of the Cesarean section scar.

RESULTS

Lower-segment uterine scars were detected in 321/324 (99.1%; 95% CI, 98.0-100) women with a history of previous Cesarean section. Sixty-three (19.4%; 95% CI, 15.1-23.8) women had evidence of deficient Cesarean scars. Using multivariate analysis, a history of multiple Cesarean sections, uterine retroflexion and the inability to visualize all Cesarean scars in women with previous multiple Cesarean sections were all shown to be significantly associated with deficient scars.

CONCLUSION

Deficient uterine scars are a frequent finding in women with a history of previous Cesarean section. The risk of scar deficiency is increased in women with a retroflexed uterus and in those who have undergone multiple Cesarean sections.

A real-time RT-PCR method for the universal detection and identification of flaviviruses

Here we describe an optimized molecular protocol for the universal detection and identification of flaviviruses. It combines the convenient real-time polymerase chain reaction (PCR) format with a broad spectrum of flavivirus detection. This assay, based on the amplification of a 269-272 nt (depending on the flavivirus tested) region at the N terminal end of the NS5 gene, enabled the amplification of 51 flavivirus species and 3 tentative species. Sequencing of the amplicons produced by reverse transcriptase (RT)-PCR permitted the reliable taxonomic identification of flavivirus species by comparison with reference sequences available in databases, using either the BLASTN algorithm or a simple phylogenetic reconstruction. The limit of detection of the assay (2-20,500 copies/reaction depending on the virus tested) allowed the detection of different flaviviruses from a series of human sera or veterinary samples. Altogether, the characteristics of this technique make it a good candidate for the identification of previously identified flaviviruses in cell culture and the investigation of field samples, and also a promising tool for the discovery and identification of new species, including viruses distantly related to "classical" arthropod-borne flaviviruses.

Signatures of hippocampal oxidative stress in aged spatial learning-impaired rodents

Neurons and glia within the hippocampus of aged, spatial learning-impaired Long-Evans rats exhibit uniquely altered gene expression profiles, and we have postulated oxidative stress as the basis for this. To test this hypothesis we quantitated the extent of protein and nucleic acid oxidative damage, evaluated the status of mitochondrial DNA integrity, and examined several signaling entities and molecular indicators frequently associated with oxidative stress and gliosis. Immunoblotting demonstrated elevated heme oxygenase-1 in the aged-impaired hippocampus and immunocytochemistry suggested that heme oxygenase-1 is largely cytosolic and at least partly neuronal in nature. In the aged-impaired group, immunoreactivity to 8-hydroxy-2'-deoxyguanosine, an oxidative nucleic acid adduct, was found to be elevated in the dentate gyrus and in area CA1 of the hippocampal formation. Isolated mitochondrial DNA was found to be significantly damaged in the aged-impaired group. In the aged learning-impaired rats only, proteins in a 65-kDa band were found to contain excessive levels of carbonyl residues. Glial activation was examined by in situ hybridization histochemistry to tumor necrosis factor alpha and by immunocytochemistry with OX-6, which detects activated microglia. White matter in aged brains exhibited a modest up-regulation of tumor necrosis factor alpha mRNA and OX-6 immunoreactivity, but the hippocampal formation expressed tumor necrosis factor alpha mRNA equivalent to young animals and few OX-6-positive microglia. The mRNA for manganese-dependent superoxide dismutase, which is elevated in the aged hippocampus, was found preferentially expressed in neurons. We conclude that aged hippocampal neurons appear to be under oxidative stress and this is more severe in the learning-impaired subjects, suggesting a possible basis for age-induced cognitive decline.

Multifrequency bioelectrical impedance estimates the distribution of body water

Multifrequency bioelectrical impedance analysis was used to estimate the ratio of extracellular water (ECW) to total body water in subjects with end-stage renal disease. The body's resistance was measured at frequencies ranging from 1 kHz to 1 MHz. The impedance index (height2/resistance) determined at low frequency (5 kHz) correlated most closely with ECW (r = 0.886) using sodium bromide dilution as the standard of comparison. In contrast, the ratio of height squared to resistance determined at high frequency (500 kHz) correlated most closely with total body water (r = 0.974) using deuterium oxide dilution as the standard of comparison. The ratio of resistance at 500 kHz to resistance at 5 kHz was directly correlated (r = 0.767) with the ratio of ECW to total body water. Multifrequency bioelectrical impedance analysis may assist in the evaluation of body water distribution in endstage renal disease and other clinical disorders of fluid volume and/or distribution.

Early diagnosis of pancreatic cancer: neutrophil gelatinase-associated lipocalin as a marker of pancreatic intraepithelial neoplasia

Pancreatic cancer is a highly lethal malignancy with a dismal 5-year survival of less than 5%. The scarcity of early biomarkers has considerably hindered our ability to launch preventive measures for this malignancy in a timely manner. Neutrophil gelatinase-associated lipocalin (NGAL), a 24-kDa glycoprotein, was reported to be upregulated nearly 27-fold in pancreatic cancer cells compared to normal ductal cells in a microarray analysis. Given the need for biomarkers in the early diagnosis of pancreatic cancer, we investigated the expression of NGAL in tissues with the objective of examining if NGAL immunostaining could be used to identify foci of pancreatic intraepithelial neoplasia, premalignant lesions preceding invasive cancer. To examine a possible correlation between NGAL expression and the degree of differentiation, we also analysed NGAL levels in pancreatic cancer cell lines with varying grades of differentiation. Although NGAL expression was strongly upregulated in pancreatic cancer, and moderately in pancreatitis, only a weak expression could be detected in the healthy pancreas. The average composite score for adenocarcinoma (4.26+/-2.44) was significantly higher than that for the normal pancreas (1.0) or pancreatitis (1.0) (P<0.0001). Further, although both well- and moderately differentiated pancreatic cancer were positive for NGAL, poorly differentiated adenocarcinoma was uniformly negative. Importantly, NGAL expression was detected as early as the PanIN-1 stage, suggesting that it could be a marker of the earliest premalignant changes in the pancreas. Further, we examined NGAL levels in serum samples. Serum NGAL levels were above the cutoff for healthy individuals in 94% of pancreatic cancer and 62.5% each of acute and chronic pancreatitis samples. However, the difference between NGAL levels in pancreatitis and pancreatic cancer was not significant. A ROC curve analysis revealed that ELISA for NGAL is fairly accurate in distinguishing pancreatic cancer from non-cancer cases (area under curve=0.75). In conclusion, NGAL is highly expressed in early dysplastic lesions in the pancreas, suggesting a possible role as an early diagnostic marker for pancreatic cancer. Further, serum NGAL measurement could be investigated as a possible biomarker in pancreatitis and pancreatic adenocarcinoma.

A randomized trial of the discontinuation of primary and secondary prophylaxis against Pneumocystis carinii pneumonia after highly active antiretroviral therapy in patients with HIV infection. Grupo de Estudio del SIDA 04/98

BACKGROUND

Prophylaxis against Pneumocystis carinii pneumonia is indicated in patients with human immunodeficiency virus (HIV) infection who have less than 200 CD4 cells per cubic millimeter and in those with a history of P. carinii pneumonia. However, it is not clear whether prophylaxis can be safely discontinued after CD4 cell counts increase in response to highly active antiretroviral therapy.

METHODS

We conducted a randomized trial of the discontinuation of primary or secondary prophylaxis against P. carinii pneumonia in HIV-infected patients with a sustained response to antiviral therapy, defined by a CD4 cell count of 200 or more per cubic millimeter and plasma HIV type 1 (HIV-1) RNA level of less than 5000 copies per milliliter for at least three months. Prophylactic treatment was restarted if the CD4 cell count declined to less than 200 per cubic millimeter.

RESULTS

The 474 patients receiving primary prophylaxis had a median CD4 cell count at entry of 342 per cubic millimeter, and 38 percent had detectable HIV-1 RNA. After a median follow-up period of 20 months (758 person-years), there had been no episodes of P. carinii pneumonia in the 240 patients who discontinued prophylaxis (95 percent confidence interval, 0 to 0.85 episode per 100 person-years). For the 113 patients receiving secondary prophylaxis, the median CD4 cell count at entry was 355 per cubic millimeter, and 24 percent had detectable HIV-1 RNA. After a median follow-up period of 12 months (123 person-years), there had been no episodes of P. carinii pneumonia in the 60 patients who discontinued prophylaxis (95 percent confidence interval, 0 to 4.5 episodes per 100 person-years).

CONCLUSIONS

In HIV-infected patients receiving highly active antiretroviral therapy, primary and secondary prophylaxis against P. carinii pneumonia can be safely discontinued after the CD4 cell count has increased to 200 or more per cubic millimeter for more than three months.

Measuring the use of mammography: two methods compared

Population studies often estimate mammography use using women's self-reports. In one North Carolina county, we compared self-report surveys with a second method--counting mammograms per population--for 1987 and 1989. Estimates from self-reports (35% in 1987, 55% in 1989) were considerably higher than those from mammogram counts (20% in 1987, 36% in 1989). We then confirmed 66% of self-reports in the past year. Self-reported use is more accurate regarding whether a woman has had a mammogram than when she had it, but self-reports accurately measure change over time.

Searching for the prototypic eye genetic network: Sine oculis is essential for eye regeneration in planarians

We have identified a sine oculis gene in the planarian Girardia tigrina (Platyhelminthes; Turbellaria; Tricladida). The planarian sine oculis gene (Gtso) encodes a protein with a sine oculis (Six) domain and a homeodomain that shares significant sequence similarity with so proteins assigned to the Six-2 gene family. Gtso is expressed as a single transcript in both regenerating and fully developed eyes. Whole-mount in situ hybridization studies show exclusive expression in photoreceptor cells. Loss of function of Gtso by RNA interference during planarian regeneration inhibits eye regeneration completely. Gtso is also essential for maintenance of the differentiated state of photoreceptor cells. These results, combined with the previously demonstrated expression of Pax-6 in planarian eyes, suggest that the same basic gene regulatory circuit required for eye development in Drosophila and mouse is used in the prototypic eye spots of platyhelminthes and, therefore, is truly conserved during evolution.