Cellular senescence, cancer and aging: the telomere connection

Telomeres are the repetitive DNA sequences and specialized proteins that form the distinctive structure that caps the ends of linear chromosomes. Telomeres allow cells to distinguish the chromosome ends from double strand DNA breaks. The telomeric structure prevents the degradation or fusion of chromosome ends, and thus is essential for maintaining the integrity and stability of eukaryotic genomes. In addition, and perhaps less widely appreciated, telomeres may also indirectly influence gene expression. The length, structure and organization of telomeres are regulated by a host of telomere-associated proteins, and can be influenced by basic cellular processes such as cell proliferation, differentiation, and DNA damage. In mammalian cells, telomere length and/or telomere structure have been linked to both cancer and aging. Here, we briefly review what is known about mammalian telomeres and the proteins that associate with them, and discuss the cellular and organismal consequences of telomere dysfunction and the evidence that cells with dysfunctional telomeres can contribute to cancer and aging phenotypes.

Characterization of GFAP expression and cell proliferation in the rat median eminence following hypophysectomy

To analyze whether the reorganization of the rat median eminence after hypophysectomy might be related to changes in glial fibrillary acidic protein (GFAP)- and cellular proliferation, the distribution of cells immunoreactive for GFAP and the proliferation rate of such cells were analyzed at 20, 40 and 60 days posthypophysectomy. For this study, four rostro-caudal regions of the median eminence were differentiated: the retrochiasmatic, preinfundibular, infundibular and postinfundibular regions. In each of these regions, three layers were studied: the ependymal, the internal and the external. At 20 and 40 days after hypophysectomy, significant increases in cellular proliferation affecting all three layers studied in the preinfundibular and infundibular regions were found. At the same time points, increases in GFAP expression were also observed. However, after 60 days, GFAP and proliferative cellular nuclear antigen (PCNA) expression decreased. Although variations of PCNA and GFAP levels were evident, no colocalisation of PCNA and GFAP was found in the cells of the median eminence in untreated or hypophysectomized rats when sections were analyzed by double immunohistochemical staining. Our results suggest that reorganization of median eminence involves alterations (or modulation) of GFAP-immunoreactive cells together with a proliferation of cells that are not GFAP-immunoreactive. This study also demonstrates that this reorganization is completed within the first two months after hypophysectomy.

Role of CD47 in the induction of human naive T cell anergy

We recently reported that CD47 ligation inhibited IL-2 release by umbilical cord blood mononuclear cells activated in the presence of IL-12, but not IL-4, preventing the induction of IL-12Rbeta(2) expression and the acquisition of Th1, but not the Th2 phenotype. Here we show that in the absence of exogenous cytokine at priming, CD47 ligation of umbilical cord blood mononuclear cells promotes the development of hyporesponsive T cells. Naive cells were treated with CD47 mAb for 3 days, expanded in IL-2 for 9-12 days, and restimulated by CD3 and CD28 coengagement. Effector T cells generated under these conditions were considered to be anergic because they produced a reduced amount of IL-2 at the single-cell level and displayed an impaired capacity 1) to proliferate, 2) to secrete Th1/Th2 cytokines, and 3) to respond to IL-2, IL-4, or IL-12. Moreover, CD47 mAb strongly suppressed IL-2 production and IL-2Ralpha expression in primary cultures and IL-2 response of activated naive T cells. Induction of anergy by CD47 mAb was IL-10 independent, whereas inclusion of IL-2 and IL-4, but not IL-7, at priming fully restored T cell activation. Furthermore, CD28 costimulation prevented induction of anergy. Thus, CD47 may represent a potential target to induce anergy and prevent undesired Th0/Th1 responses such as graft vs host diseases, allograft rejection, or autoimmune diseases.

Bidirectional negative regulation of human T and dendritic cells by CD47 and its cognate receptor signal-regulator protein-alpha: down-regulation of IL-12 responsiveness and inhibition of dendritic cell activation

Proinflammatory molecules, including IFN-gamma and IL-12, play a crucial role in the elimination of causative agents. To allow healing, potent anti-inflammatory processes are required to down-regulate the inflammatory response. In this study, we first show that CD47/integrin-associated protein, a ubiquitous multispan transmembrane protein highly expressed on T cells, interacts with signal-regulator protein (SIRP)-alpha, an immunoreceptor tyrosine-based inhibition motif-containing molecule selectively expressed on myelomonocytic cells, and next demonstrate that this pair of molecules negatively regulates human T and dendritic cell (DC) function. CD47 ligation by CD47 mAb or L-SIRP-alpha transfectants inhibits IL-12R expression and down-regulates IL-12 responsiveness of activated CD4(+) and CD8(+) adult T cells without affecting their response to IL-2. Human CD47-Fc fusion protein binds SIRP-alpha expressed on immature DC and mature DC. SIRP-alpha engagement by CD47-Fc prevents the phenotypic and functional maturation of immature DC and still inhibits cytokine production by mature DC. Finally, in allogeneic MLR between mDC and naive T cells, CD47-Fc decreases IFN-gamma production after priming and impairs the development of a Th1 response. Therefore, CD47 on T cells and its cognate receptor SIRP-alpha on DC define a novel regulatory pathway that may be involved in the maintenance of homeostasis by preventing the escalation of the inflammatory immune response.

Evaluation of three methods to measure anti-Brucella IgM antibodies and interference of IgA in the interpretation of mercaptan-based tests

The results of a dipstick assay for the detection of immunoglobulin M (IgM) to Brucella smooth lipopolysaccharide (S-LPS) correlated with those of an enzyme-linked immunosorbent assay (ELISA) for IgM and of the serum agglutination test (SAT) performed with and without dithiothreitol. Two sera which were dithiothreitol-sensitive and were dipstick negative were shown to contain specific IgA. The dipstick assay is recommended as a simple method for detecting specific IgM antibodies in acute-phase brucellosis patients.

Cadmium accumulation and distribution in slaughtered horse kidneys from the Argentine central region

In this paper we report the results of surveys conducted in Argentina between 1997 and 1998 to know the Cd concentrations in kidney from horses of different age, sex, and origin. Cd in renal cortex and medulla was positively correlated, and higher concentrations in the cortex were found. No significant differences between values from left and right kidneys of the same animal were found. An increase in Cd levels with age of animals were observed, and no sex incidence was verified in renal Cd composition. No detectable residues were found in the fetuses tested. Levels observed in Argentine equines (n = 102) ranged from 4.3 to 83.8 microg Cd/g in kidney cortex, lower than those reported by other authors but higher than the action levels proposed by Argentine meat tissue species regulations. Therefore, the study remarks on the convenience of monitoring Cd in Argentine equines and gives relevant information for regulatory purposes to consider the limitation in the use of horse kidney as food for either human or animals.

Treatment with continuous positive airway pressure is not effective in patients with sleep apnea but no daytime sleepiness. a randomized, controlled trial

BACKGROUND

The sleep apnea-hypopnea syndrome is defined by a pathologic number of respiratory events during sleep (the apnea-hypopnea index, defined as the number of apnea and hypopnea episodes per hour) and daytime symptoms (mostly, excessive sleepiness). In patients with the sleep apnea syndrome, treatment with continuous positive airway pressure (CPAP) normalizes both the apnea-hypopnea index and diurnal symptoms. However, the effect of CPAP in persons with a pathologic apnea-hypopnea index without daytime sleepiness is unclear.

OBJECTIVE

To investigate the short-term effects of CPAP on quality of life, objective sleepiness, cognitive function, and arterial blood pressure in nonsleepy patients with a pathologic apnea-hypopnea index.

DESIGN

Multicenter randomized, placebo-controlled, parallel-group study.

SETTING

Six teaching hospitals in Spain.

PATIENTS

55 patients with an apnea-hypopnea index of 30 or greater who did not have daytime sleepiness (Epworth Sleepiness Scale score </= 10).

INTERVENTION

Patients were randomly assigned to receive optimal (n = 29) or sham (n = 25) CPAP and were observed for 6 weeks.

MEASUREMENTS

Quality of life, objective sleepiness (Multiple Sleep Latency Test score), cognitive function, and arterial blood pressure.

RESULTS

The intervention and control groups were similar in terms of mean (+/-SE) age (54 +/- 2 vs. 52 +/- 2 years), apnea-hypopnea index (54 +/- 3 vs. 57 +/- 4), Epworth Sleepiness Scale score (7.0 +/- 0.4 vs. 7.0 +/- 0.4) and adherence to CPAP treatment (5.0 +/- 0.4 vs. 4.0 +/- 0.5 hours/d). Other variables, such as quality of life, cognitive function, and arterial blood pressure, were also similar in both groups before treatment. After 6 weeks of CPAP or sham CPAP, none of these variables changed significantly.

CONCLUSION

In patients with an apnea-hypopnea index of 30 or greater and no subjective daytime sleepiness, CPAP does not modify quality of life, objective sleepiness, vigilance, attention, memory, information processing, visuomotor coordination, or arterial blood pressure. Treatment with CPAP is therefore not indicated in nonsleepy patients with a pathologic apnea-hypopnea index.

Anisakis simplex-sensitized patients: should fish be excluded from their diet?

BACKGROUND

Anisakis simplex (A.s.) allergy is an emerging disease. The third-stage larvae of this nematode are a source of hidden allergens in fish. There are no clear guidelines concerning dietary restrictions for patients with serum-specific IgE to this parasite.

OBJECTIVE

To follow up the clinical data and immunological parameters of patients sensitized to A.s. during 6 to 23 months.

METHODS

The clinical symptoms and serologic status of 17 patients with specific IgE and positive skin prick test results to A.s. were studied prospectively. Six of these had anaphylaxis (ANA) attributed to A.s. and 11 patients experienced concomitant chronic urticaria (CU). All patients were advised not to eat fish for 6 months.

RESULTS

Four patients from the ANA group excluded fish, and ANA did not recur. Two other patients with ANA refused to exclude fish; one remained free of symptoms and the other experienced several urticarial episodes. During this 6-month period total IgE levels decreased in all six ANA patients; specific IgE for A.s. decreased in four patients and increased in two. Two patients from the CU group did not exclude fish, and symptoms persisted in these two patients. Clinical improvement was observed in 78% of the patients with CU who excluded fish. Total and specific IgE levels decreased in all the patients with CU.

CONCLUSIONS

Because ANA symptoms are very severe, patients should always be advised to exclude fish until specific food allergens are identified. However, in patients with CU and specific IgE to A.s., only the clinical response to fish ingestion will determine the need for strict fish avoidance.

[Hepatitis C virus genotypes. Study of 302 patients coinfected by the human immunodeficiency virus]

BACKGROUND

To study the distribution of different HCV genotypes in HIV-infected patients.

PATIENTS AND METHOD

This study was carried out in 302 HIV/HCV-coinfected patients who were followed-up at the HIV/AIDS Unit of the Arnau de Vilanova University Hospital of Lleida (Spain). HCV genotypes were determined by Inno-Lipa HCV II technique (Innogenetics, Belgium).

RESULTS

143 patients (51.43%) had a genotype-1, followed by genotype-3 (81 patients; 29.13%), genotype-4 (53 patients; 19.06%), and genotype-2 (one patient; 0.35%). It was not possible to know the genotype in 24 patients (NT).

CONCLUSIONS

In our health care area, HCV genotype-1 was the commonest among HIV/HCV-coinfected patients. However, a given HIV-infected patient with HCV antibodies has practically the same probability of having a genotype-1 as a genotype non-1.

Estradiol influences the LH response to met-enkephalin. An immunocytochemical and morphometric study

In order to test the possible role of estradiol in the response of the LH-adenohypophyseal cells to the administration of met-enkephalin in the albino male rat, an immunocytochemical (peroxidase-antiperoxidase), morphometric (cellular and nuclear areas and numerical density) and radioimmunoassay (LH serum levels at the moment of sacrifice) study was carried out. The intraventricular administration of met-enkephalin (150 micrograms in 25 microliters of distilled water) does not produce any changes in the parameters considered. However, when the animals were pretreated with estradiol (chronically, 15 days), met-enkephalin produced a significant decrease in all the parameters considered.

Angiotensin-(1-7) does not affect norepinephrine neuronal uptake or catabolism in rat hypothalamus and atria

1. Since we previously reported that angiotensin-(1-7) [Ang-(1-7)] increases or inhibits norepinephrine (NE) release in rat atria or hypothalamus, respectively, the present work was undertaken to investigate the effect of the heptapeptide on NE neuronal uptake and metabolism in atria and hypothalamus isolated from rats. 2. Ang II (1-10 microM) caused a decrease in neuronal NE uptake in both atria and hypothalami isolated from rats. On the contrary, tissues incubated with [3H]NE in the presence of 0.1-10 microM Ang-(1-7) showed no modification in [3H]NE content with respect to the control group, suggesting that the heptapeptide did not modify [3H]NE neuronal uptake. 3. To study the effect of the heptapeptide on NE catabolism, monoamine-oxidase (MAO) and catechol-O-methyltransferase (COMT) activities were determined. Pretreatment of the tissue with Ang-(1-7) (0.1-1.0 microM) showed a tendency to diminish MAO activity in rat atria, while no significant changes were observed in hypothalamic MAO activity. Moreover, the heptapeptide (0.1-1.0 microM) did not affect central COMT activity with respect to the control group. 4. Present results allow us to conclude that Ang-(1-7) interacts with noradrenergic neurotransmission by increasing or inhibiting NE release at the peripheral and central levels, respectively, without affecting either the neurotransmitter neuronal uptake or catabolism.

[Short-stay lung resection surgery]

We report a prospective study applying a short-stay lung resection program for all patients requiring such surgery with the aim of shortening mean hospital stay in our service (9.5 days) by half. All patients who underwent surgery from November 1998 to November 1999 requiring lung resection surgery were enrolled in the short-stay study, classified in two groups. Group A met the criteria for enrollment and a stay of 5 days was predicted. Group B were those who did not meet the criteria marked by the program and for whom a 5-day stay could not be predicted. Sixty-four patients were enrolled (25 in group A [39.1%] and 39 in group B [60.9%]). After application of the program, the mean stay for all 64 patients was 6.4 days, with group A patients staying a mean 5.3 days and group B patients staying a mean 7.1 days.

CD47 ligation selectively inhibits the development of human naive T cells into Th1 effectors

The CD47 Ag, also named integrin-associated protein, was recently reported to regulate the production of IL-12 by human monocytes and dendritic cells. The present study shows that CD47 ligation by CD47 mAb in primary cultures of cord blood mononuclear cells inhibits IL-12-driven Th1 cell development, as revealed by the cytokine secretion profile at restimulation and IFN-gamma production at the single-cell level. F(ab')(2) fragments of CD47 mAb or the synthetic peptide 4N1K, corresponding to the CD47 binding site of thrombospondin, display the same activity. CD47 engagement does not change the phenotype of IL-12-primed cells from Th1 to Th2 or affect IL-4-induced Th2 cell development. Moreover, CD47 mAb inhibits IL-12- but not IL-4-induced IL-2 production as well as IFN-gamma in primary cultures, which was correlated with a decrease of the IL-12Rbeta2 chain expression. Inclusion of exogenous IL-2 at priming corrects IL-12R expression as well as the inhibition of Th1 cell development. The data thus underline the role of IL-2 in Th1 cell development and further suggest that targeting IL-2 and IL-12 simultaneously may have some therapeutic advantage in Th1 autoimmune diseases.

S-adenosylmethionine prevents hepatic tocopherol depletion in carbon tetrachloride-injured rats

In various experimental models, S-adenosylmethionine (SAMe) has been shown to reduce liver injury by preventing depletion of glutathione, one of the antioxidant systems that plays a critical role in defence against oxidative stress. On the other hand, alpha-tocopherol may be decreased in liver diseases, and treatment with this vitamin reduces liver injury in CCl(4)-treated rats. Since there is a close relationship among the different antioxidant systems (mainly glutathione, alpha-tocopherol and ascorbic acid), we have assessed whether, as well as restoring hepatic glutathione content, SAMe has any effect on liver alpha-tocopherol and ascorbic acid levels in CCl(4)-injured rats. Four groups of seven male Wistar rats treated for 9 weeks were studied: rats induced to cirrhosis with CCl(4), rats induced to cirrhosis plus SAMe administration (10 mg x kg(-1) x day(-1)) and their respective controls. Liver samples were obtained for measuring levels of glutathione, alpha-tocopherol, ascorbic acid and thiobarbituric acid-reactive substances (TBARS), and hydroxyproline concentration as an index of collagen content. The hydroxyproline content was higher in CCl(4)-injured rats than in the control group (4.4+/-1.8 and 1.1+/-0.3 micromol/g respectively; P<0.05). In CCl(4)-injured rats, SAMe administration decreased collagen content (2.7+/-1.0 microl/g; P<0.05) and TBARS, and corrected glutathione depletion. alpha-Tocopherol was significantly lower in CCl(4)-injured rats than in controls (17.3+/-4.9 and 23.0+/-4.0 micromol/g respectively; P<0.05). By contrast, alpha-tocopherol levels were similar (23.8+/-5.1 micromol/g) in CCl(4)-injured rats receiving SAMe and in controls. In CCl(4)-injured rats, liver ascorbic acid was decreased in comparison with controls (4.9+/-1.8 and 8.2+/-1.0 micromol/g respectively; P<0.05), levels which were not replenished by SAMe (4.6+/-0.4 micromol/g). In conclusion, SAMe not only decreases fibrosis and protects against hepatic glutathione depletion, but has a further antioxidant effect of preventing alpha-tocopherol depletion in CCl(4)-injured rats.

Diagnosis of tuberculous pleuritis by the measurement of soluble interleukin 2 receptor in pleural fluid

OBJECTIVE

As soluble interleukin-2 receptor (sIL-2R) is a marker of T-lymphocyte activation, we sought to determine whether its measurement in pleural fluid is diagnostically useful in tuberculous pleurisy.

DESIGN

We compared the concentrations of sIL-2R in pleural samples of 23 patients with tuberculous pleurisy and 109 patients with non-tuberculous effusions (34 malignant, 34 parapneumonic, 27 transudates and 14 miscellaneous). sIL-2R was measured by a commercial ELISA test and its performance was evaluated using receiver operating characteristic (ROC) analysis.

RESULTS

The mean values of pleural sIL-2R were 9179 U/mL in patients with tuberculous pleurisy vs 3664 U/mL in patients with malignancy, 2603 U/mL in patients with parapneumonic effusions, 1016 U/mL in patients with transudates, and 1906 U/mL in patients with miscellaneous diseases (P < 0.0001). A ROC curve identified the best cut-off at 4700 U/mL, yielding measures for sensitivity (0.91), specificity (0.94) and accuracy (0.94).

CONCLUSIONS

The results of this pilot study suggest that pleural sIL-2R appears to be clinically useful for differentiating between tuberculous and non-tuberculous pleural effusions.

Habitually sleepy drivers have a high frequency of automobile crashes associated with respiratory disorders during sleep

Sleepiness is a common cause of traffic crashes with a cost of billions of dollars per year. A recent study has found that 2 to 3% of drivers are habitually sleepy while driving. However, there has not been a controlled study to define the characteristics, driving performance, or automobile crash rate of habitually sleepy drivers. The prevalence of respiratory disorders during sleep, and whether these respiratory disorders contribute to the increased automobile crash frequency, is unknown in habitually sleepy drivers. We interviewed 4,002 randomly selected drivers to define the prevalence of drivers who are habitually sleepy while driving. We studied the habitually sleepy drivers and an age- and sex-matched control group of drivers. These studies included reporting of daytime sleepiness, automobile crashes, driving performance and sleep studies. Of the 4, 002 drivers interviewed, 145 (3.6%, confidence interval [CI] = 3.1 to 4.3) were habitually sleepy while driving. The habitually sleepy drivers reported a significantly higher frequency of auto crashes than control subjects (the adjusted odds ratio [OR] was 13.3, CI = 4. 1 to 43). The habitually sleepy drivers had a significantly higher prevalence of respiratory sleep disorders than control subjects. For a total respiratory events index (apneas, hypopneas, and other respiratory effort-related arousals) >/= 15 the adjusted OR was 6.0, CI = 1.1 to 32. In the habitually sleepy drivers group, the frequency of sleep apnea (apnea-hypopnea index) between subjects with or without auto crashes was not statistically different. However, if we consider total respiratory events index, this frequency of respiratory sleep disorders was significantly higher in subjects with automobile crashes (the adjusted OR for a total respiratory event index >/= 15 was 8.5, CI = 1.2 to 59). Habitually sleepy drivers are a large group of drivers (1 of 30 drivers) who are involved in several fold more automobile crashes than control subjects. As these excess auto crashes can be explained in part by the presence of respiratory disorders during sleep, which are treatable, many automobile crashes in these sleepy drivers may be preventable. Our findings suggest that asking about excessive sleepiness while driving may better predict which subjects with breathing disorders during sleep have crashes than asking about overall sleepiness.

Pleural SC5b-9: a test for identifying complicated parapneumonic effusions

BACKGROUND AND OBJECTIVES We have tested whether the complement activation products SC5b-9 and C3a-desArg are useful to distinguish complicated (CPE) from uncomplicated parapneumonic effusions (UPE).

DESIGN

A total of 66 patients were enrolled in the study: 5 with empyema, 19 with CPE, 12 with UPE, and 30 transudates who served as controls. SC5b-9 and C3a-desArg were measured by commercial ELISA tests, and their performances were evaluated using receiver operating characteristic (ROC) analysis.

RESULTS

Patients with CPE had higher mean levels of pleural SC5b-9 (8,218 microg/l) and C3a-desArg (8,790 microg/l) than those with UPE (2,227 and 3,772 microg/l, respectively; p < 0.0001), whereas concentrations in the latter were comparable with controls for the SC5b-9 test. Empyemas had a wide range of pleural complement activation product values. Pleural SC5b-9 and C3a-desArg showed very high diagnostic accuracy in the diagnosis CPE (90.3 and 77.8%, respectively) when corresponding cutoff points of 2,000 and 4,000 microg/l were used. In a stepwise logistic regression analysis, the combination of SC5b-9 >/=2,000 microg/l, LDH >/=1,000 U/l and a pleural polymorphonuclear percentage >/=85% provided the highest discriminative power for the diagnosis of CPE (area under ROC curve 0.97).

CONCLUSION

This pilot study suggests that measurement of pleural SC5b-9 can be useful in the workup of patients with a parapneumonic effusion in order to differentiate CPE from UPE.

A non-destructive method to determine the safranal content of saffron (Crocus sativus L.) by supercritical carbon dioxide extraction combined with high-performance liquid chromatography and gas chromatography

A supercritical carbon dioxide extraction method to obtain selectively volatile compounds of saffron without sample destruction has been developed. The influence of both pressure and temperature was studied, 20 MPa and 100 degrees C being the best conditions to extract the total safranal content. A decrease in supercritical fluid density was shown to be a critical parameter for enhancing the extraction power of carbon dioxide. For all the assay conditions, the extracts mainly contained safranal and HTCC, as demonstrated by gas chromatography and high-performance liquid chromatography analyses. Both chromatographic methods were suitable for safranal quantification and showed excellent agreement. Supercritical extracts from five different saffron types were studied by high-performance liquid chromatography and their safranal contents were determined.

Enhanced DNA binding and activation of transcription factors NF-kappa B and AP-1 by acetaldehyde in HEPG2 cells

Because transcription factors NF-kappaB and activator protein-1 (AP-1) are known to regulate gene expression, we have analyzed the role of acetaldehyde in the activation of NF-kappaB and AP-1 in HepG2 cells. Binding activity and transactivation of NF-kappaB and AP-1 were determined by gel retardation assays and transfection of a luciferase reporter construct controlled by kappaB and AP-1 binding sites, respectively. Acetaldehyde enhanced the DNA binding of NF-kappaB and AP-1 by 1 and 4 h, respectively, increasing the kappaB- and AP-1-dependent luciferase expression. Supershift assays revealed the presence of NF-kappaB heterodimers p65/p50 and p50/p52, whereas nuclear c-Jun levels correlated with the DNA binding of AP-1. The enhanced binding of NF-kappaB to DNA by acetaldehyde in intact cells was accompanied by the proteolytic degradation of IkappaB-alpha. However, the addition of acetaldehyde to cytostolic extracts from untreated Hep G2 cells did not affect the DNA binding of AP-1 but activated the NF-kappaB heterodimer p65/p50 in the absence of IkappaB-alpha degradation. Preincubation of HepG2 cells with protein kinase C inhibitors abolished the enhanced DNA binding of NF-kappaB and AP-1 caused by acetaldehyde. Hence, these findings uncover a previously unrecognized role for acetaldehyde in the activation of NF-kappaB and AP-1, which may be of relevance in the alcohol-induced liver disease.

[Features of patients with bronchial asthma seen at the emergency department of a referral hospital in a semirural area]

Bronchial asthma is a chronic disease whose prevalence and severity is increasing. Appropriate treatment of exacerbation seems to affect the subsequent course of disease.

OBJECTIVES

To assess the extent of application of guidelines for treating exacerbations of asthma and to describe the clinical and epidemiological characteristics of patients.

PATIENTS AND METHODS

All patients presenting with exacerbations to the emergency room of a referral hospital in a semi-rural area of Catalonia were enrolled consecutively. We recorded symptoms, function and treatment variables during the emergency and when the patient was stable, at which time we also administered the Asthma Quality of Life Questionnaire (AQLQ).

RESULTS

Forty-seven percent of patients resided in rural villages. Seventy-one percent lived in the area served by our hospital. Of the remaining patients, 57% came from municipalities in the Baix Empordà area, 29% in Alt Empordà area and 14% in La Selva area. Seventy-one percent went to the hospital directly from home, 66% of them were in the province of Girona; 75% of those homes were within urban areas. Of the 29% who had been sent to the emergency room by a physician, 71% were from a rural area. The 119 asthma exacerbations treated (114 patients, 71 females, 42 +/- 23 years) accounted for 0.3% of all emergency room visits. The exacerbation was considered severe in 31%, moderate in 47% and mild in all remaining cases. Eighty-eight percent of patients had experienced an exacerbation before. Symptoms were often present before the attack, but nearly half the patients were receiving relatively inadequate medication. Peak expiratory flow and oxygen saturation were recorded in 70% of cases and both variables improved after initial treatment (250 +/- 97 to 349 +/- 92 l/min, p < 0.001; and 92 +/- 7 to 96 +/- 2%, p < 0.01, respectively). All patients received inhaled salbutamol, 44% inhaled corticosteroids and 73% intravenous corticosteroids. A quarter of the patients were admitted to the ward (0.4% of all admissions) and 4% were admitted to the intensive care unit. Patients stayed 8.8 +/- 1.4 h in the emergency room. When patients were stable, asthma was severe in 14%, moderate in 42%, mild but persistent in 27%, and occasional in 17%. The total score on the AQLQ was 13.8 +/- 11.1, with mood being the dimension with the highest score (5.1 +/- 4.9). This score, along with social restriction, were lowest in the group of patients with chronic airflow obstruction.

CONCLUSIONS

Nearly half the patients were from rural villages most of which were located outside the zone served directly by our hospital. The preference for specialized medical attention would explain the percentage of patients seen who did not belong to the assigned area. Difficulty of access to the hospital from certain rural areas would account for the greater number of rural patients who had been referred by a physician. Clinical management and monitoring of asthmatic patients with exacerbation could be improved by greater diffusion and application of guidelines. It would be interesting to incorporate come sort of questionnaire on quality of life while taking a patient's history.

CD47 engagement inhibits cytokine production and maturation of human dendritic cells

Upon encounter with bacterial products, immature dendritic cells (iDCs) release proinflammatory cytokines and develop into highly stimulatory mature DCs. In the present study, we show that human monocyte-derived DCs functionally express the CD47 Ag, a thrombospondin receptor. Intact or F(ab')2 of CD47 mAb suppress bacteria-induced production of IL-12, TNF-alpha, GM-CSF, and IL-6 by iDCs. 4N1K, a peptide derived from the CD47-binding site of thrombospondin, also inhibits cytokine release. The inhibition of IL-12 and TNF-alpha is IL-10-independent inasmuch as IL-10 production is down-modulated by CD47 mAb and blocking IL-10 mAb fails to restore cytokine levels. CD47 ligation counteracts the phenotypic and functional maturation of iDCs in that it prevents the up-regulation of costimulatory molecules, the loss of endocytic activity, and the acquisition of an increased capacity to stimulate T cell proliferation and IFN-gamma production. Interestingly, regardless of CD47 mAb treatment during DC maturation, mature DC restimulated by soluble CD40 ligand and IFN-gamma, to mimic DC/T interaction, produce less IL-12 and more IL-18 than iDCs. Finally, CD47 ligation on iDCs does not impair their capacity to phagocytose apoptotic cells. We conclude that following exposure to microorganisms, CD47 ligation may limit the intensity and duration of the inflammatory response by preventing inflammatory cytokine production by iDCs and favoring their maintenance in an immature state.

The effect of a single intravenous dose of metamizol 2 g, ketorolac 30 mg and propacetamol 1 g on haemodynamic parameters and postoperative pain after heart surgery

Although nonopiate analgesics may be particularly useful in the immediate postoperative period after major surgery, their use has been associated with haemodynamic adverse effects during postoperative pain treatment and in critically ill patients in intensive care. The effect of a single intravenous dose of metamizol (dipyrone) 2 g, ketorolac 30 mg and propacetamol 1 g on haemodynamic variables and pain control in the immediate postoperative period after heart surgery is compared. Seventy-two patients undergoing elective coronary and/or heart valve surgery, were included in a cohort study of 1-years duration (1998). After weaning from mechanical ventilation and extubation, haemodynamic variables and a 4-point verbal rating pain scale were asseseed at base-line and 60 min after the administration of a single doses of metamizol, ketorolac or propacetamol. The Student's t-test for paired samples was used to compare changes produced by the study medications. A significant, but small, decrease in radial artery blood pressure was observed in all treatment groups which had little clinical relevance; no vasodilator effects were observed and ventricular function showed only minor changes: propacetamol decreased cardiac index by 10% and a 15% decrease in right ventricular work was also observed. Metamizol and ketorolac produced a 10% decrease in the left ventricular work index. Pain scores showed a statistically significant decrease in all treatment groups. The analgesic effects of metamizol, ketorolac and propacetamol were not associated with a clinically significant impairment in haemodynamic function when administered to haemodynamically stable patients.

Usefulness of pleural complement activation products in differentiating tuberculosis and malignant effusions

OBJECTIVE

To determine whether measurement of the complement activation products SC5b-9 and C3a-desArg in pleural fluid can reliably differentiate tuberculous from malignant pleural effusions.

DESIGN

Twenty-four patients with tuberculous pleuritis, 29 with malignant pleural effusion, and 30 control subjects with transudates were enrolled in the study. SCSb-9 and C3a-desArg were measured in pleural fluid using commercial ELISA tests, and their performances were evaluated using receiver operating characteristic (ROC) analysis.

RESULTS

Patients with tuberculous pleuritis had higher mean levels of pleural SC5b-9 (5052 microg/L) and C3a-desArg (7436 microg/L) than those with malignant effusions (1048 and 2835 microg/L, respectively), whereas only SC5b-9 concentrations in the latter were comparable with controls. The area under the ROC curve (AUC) was 0.84 for SC5b-9 and 0.81 for C3a-desArg. Pleural SC5b-9 showed an accuracy of 80.8%, compared with 78.8% for C3a-desArg, when cut-off points of 1500 and 4500 microg/L, respectively, were used. Using a stepwise logistic regression model, the combination of pleural SCSb-9 > or =1500 microg/L, age < or =35 years, and pleural monocyte percentage > or =90% provided the highest accuracy for tuberculous pleurisy (88.5%, AUC 0.95).

CONCLUSION

This pilot study suggests that pleural SC5b-9 is clinically useful for differentiating tuberculous and malignant pleural effusions.

Bacteremic pneumonia due to Staphylococcus aureus: A comparison of disease caused by methicillin-resistant and methicillin-susceptible organisms

We performed a prospective study of all patients with bacteremic pneumonia due to Staphylococcus aureus over a period of 6 years during an outbreak of methicillin-resistant S. aureus (MRSA). Patients with bacteremic pneumonia due to MRSA (32 cases) or methicillin-susceptible S. aureus (MSSA; 54 cases) were compared. The patients with MRSA pneumonia were older and were more likely than those with MSSA pneumonia to have predisposing factors for acquisition of the infection. There were no differences in clinical findings, radiological pattern, or complications in clinical evolution among patients with MRSA and MSSA pneumonia. Mortality was significantly higher among MSSA-infected patients treated with vancomycin than among those treated with cloxacillin (47% vs. none; P<.01). Multivariate analysis (stepwise logistic regression method) showed a relationship between mortality and the following variables: septic shock (odds ratio [OR], 61), vancomycin treatment (OR, 14), and respiratory distress (OR, 8).

Drug glucuronidation and hepatic lipid microsomal membrane profile in cholestatic rats followed paracetamol intoxication

The uridin-diphosphoglucuronyl-transferase (UDP-GT) is a membrane-bound enzyme responsible for glucuronidation of endogenous and exogenous compounds. This work established the UDP-GT activity and its lipid membrane microenvironment in two experimental models: acute paracetamol intoxication, and cholestasis followed by acute paracetamol intoxication. Cholestasis was performed by bile duct ligation. After 7 days animals were injected with paracetamol (BDL-APAP group). Sham-operated rats were injected at day 7 with paracetamol (APAP group). Cholestatic and sham-operated rats injected with vehicle (BDL and control groups). UDP-GT activity was measured by a kinetic method for different substrates. Microsomal membrane phospholipid composition, cholesterol content and ultrastructure were determined. BDL-APAP group showed an increment in the UDP-GT activity except for chloramphenicol, morphine and paracetamol if compared to controls and to BDL group. The same increment was observed when BDL-APAP was compared to APAP except for chloramphenicol and lorazepam. Between BDL and APAP groups similar levels of activity were detected except for paracetamol. Microsomal phospholipid profile: phosphatidylcholine showed the lowest content in the BDL group, with a significant recovery in the BDL-APAP and APAP groups. Phosphatidylserine was markedly decreased in the APAP group compared to the rest and phosphatidylinositol was decreased in all the groups if compared to control values. An increment of phosphatidylethanolamine was seen in the APAP and BDL-APAP groups if compared to BDL and control values. A significant increment of microsomal cholesterol content was seen in BDL. Under these conditions, a different lipid microenvironment is produced, resulting in an increment of the enzyme activity for a variety of substrates.

[Immunoglobulin rearrangement in the differential diagnosis of primary gastric lymphoma]

BACKGROUND

The traditional methods to distinguish Chronic Follicular Gastritis and Primary Gastric Lymphoma do not allow an adequate definitive diagnosis in a significant number of cases. The molecular Biology diagnostic methods are based on the rearrangement of immunoglobulin genes. The polymerase chain reaction (PCR) specifically amplifies this rearrangement and allows molecular analysis of minimal tissue samples obtained with endoscopical biopsies.

AIM

To test the usefulness of this PCR method in the differential diagnosis between Chronic Follicular Gastritis and Primary Gastric Lymphoma.

MATERIAL AND METHODS

We analyzed the endoscopical biopsies of six Chronic Follicular Gastritis cases and eight surgically treated Primary Gastric Lymphoma cases, six with the correct diagnosis in the endoscopical biopsies and two with a diagnosis of Chronic Follicular Gastritis.

RESULTS

A policlonal immunoglobulin rearrangement was found in the six cases with Chronic Follicular Gastritis. A monoclonal arrangement was found in 5 of 6 biopsies with the diagnosis of Primary Gastric Lymphoma. The same monoclonal rearrangement was observed in the two biopsies incorrectly diagnosed as Chronic Follicular Gastritis.

CONCLUSIONS

PCR analysis of immunoglobulin rearrangement is a useful method in the differential diagnosis between Chronic Follicular Gastritis and Primary Gastric Lymphoma.

Lidocaine and monoethylglycinexylidide serum determinations to analyze liver function of cirrhotic patients after oral administration

Our aim was to compare standard liver function tests (serum bilirubin, serum albumin and prothrombin concentration), with lidocaine and monoethylglycinexylidide pharmacokinetic parameters, after oral lidocaine administration, to assess hepatic function of cirrhotic individuals. Twenty-one consecutive cirrhotic patients, nine consecutive acute hepatitis patients, and nine healthy individuals received oral lidocaine. Lidocaine and monoethylglycinexylidide serum concentrations were determined by the TDx system. Cirrhotic patients had higher lidocaine and lower monoethylglycinexylidide serum concentrations and differences in its pharmacokinetic variables, compared to control and hepatitis groups (P < 0.05). Sensitivity of lidocaine serum determinations (100%) was greater than sensitivity of serum bilirubin (57%), serum albumin (62%), and prothrombin concentrations (43%) and monoethylglycinexylidide serum concentrations (57%) in differentiating cirrhotic individuals from controls. In conclusion, after oral administration, lidocaine and monoethylglycinexylidide pharmacokinetic parameters are significantly altered in cirrhotic patients compared to normal and acute hepatitis subjects. Lidocaine pharmacokinetic parameters would be better than those of monoethylglycinexylidide and standard liver function tests in the evaluation of liver function of cirrhotic patients.

Serotonin in golden hamster testes: testicular levels, immunolocalization and role during sexual development and photoperiodic regression-recrudescence transition

Serotonin (5-HT) is found in the gonads and accessory reproductive organs of several species. The golden (Syrian) hamster is a seasonal breeder. Exposure of male adult hamsters to short days for 14 weeks results in a severe gonadal regression, while after a photoinhibition period of 22 weeks a spontaneous testicular recrudescence occurs. The aim of this study was to investigate the presence of 5-HT and its major metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the gonads of golden hamsters, its immunolocation and its physiological role in the testis. The influence of age and photoperiod was also analyzed. Hamsters of 23, 36, 46, 60 and 90 days of age were kept in long photoperiod (LP: 14:10 h light/dark), and adult animals were exposed either to LP or to short photoperiod (SP: 6:18 h light/dark) for 14 and 22 weeks. Testicular parenchyma and capsule levels of 5-HT and 5-HIAA increased significantly at ages of 36 and 60-90 days, but decreased markedly during the exposure of adult hamsters to SP for 14 and 22 weeks. Mast cells were found exclusively in the testicular capsule. The testicular number of mast cells increased concomitantly with age, but decreased in adult hamsters exposed to SP. Mast and Leydig cells presented 5-HT-positive immunoreactivity. During sexual maturation as well as during the transfer of adult hamsters from LP to SP, the 5-HIAA/5-HT ratio showed the highest values in active adult animals, indicating that the increase in testicular 5-HT levels in adulthood is accompanied by an augment in 5-HT turnover. In vitro basal and hCG-stimulated testosterone production was significantly inhibited in presence of physiological concentrations of 5-HT. In conclusion, the present studies demonstrate the existence of 5-HT in mast cells and Leydig cells of hamster testes, as well as describe an inhibitory action of this neurotransmitter on gonadal testosterone production. Furthermore, the age-dependent and photoperiodic-related changes detected in testicular 5-HT levels suggest that this neurotransmitter might act as an important local modulator of the action of gonadotropins on steroidogenesis during sexual development and during the photoperiodic regression-recrudescence transition in the golden hamster.

Immunohistochemical evidence of the presence of aromatase P450 in the rat hypophysis

In order to analyze whether aromatase is present in the hypophysis of adult rats, we have performed an immunohistochemical study in young adult male and female rats. Our study has revealed that the hypophysis of adult rats contains aromatase, although marked differences are found between the sexes. The hypophyses of male rats have cells immunoreactive for the enzyme, 34.40% of these hypophyseal cells showing reaction. By contrast, cells from female rats show very little reaction, only 0.84% of them being reactive. No significant differences in the percentage of immunoreactive cells between one phase and another are observed during the estrous cycle. Our results point to the immunohistochemical expression of aromatase in the hypophysis of adult rats and at the same time suggest that its expression is sex-dependent. The enzyme may therefore be involved in the regulation of adenohypophyseal cytology by androgens.

The vitronectin receptor and its associated CD47 molecule mediates proinflammatory cytokine synthesis in human monocytes by interaction with soluble CD23

The vitronectin receptor, alphavbeta3 integrin, plays an important role in tumor cell invasion, angiogenesis, and phagocytosis of apoptotic cells. CD47, a member of the multispan transmembrane receptor family, physically and functionally associates with vitronectin receptor (VnR). Although vitronectin (Vn) is not a ligand of CD47, anti-CD47 and beta3 mAbs suppress Vn, but not fibronectin (Fn) binding and function. Here, we show that anti-CD47, anti-beta3 mAb and Vn, but not Fn, inhibit sCD23-mediated proinflammatory function (TNF-alpha, IL-12, and IFN-gamma release). Surprisingly, anti-CD47 and beta3 mAbs do not block sCD23 binding to alphav+beta3+ T cell lines, whereas Vn and an alphav mAb (clone AMF7) do inhibit sCD23 binding, suggesting the VnR complex may be a functional receptor for sCD23. sCD23 directly binds alphav+beta3+/CD47(-) cell lines, but coexpression of CD47 increases binding. Moreover, sCD23 binds purified alphav protein and a single human alphav chain CHO transfectant. We conclude that the VnR and its associated CD47 molecule may function as a novel receptor for sCD23 to mediate its proinflammatory activity and, as such, may be involved in the inflammatory process of the immune response.

[Bacteremia by Staphylococcus aureus: analysis of 311 episodes]

BACKGROUND

The aim of this study was to set up the differences between nosocomial and community acquired S. aureus bacteremia, to identify the features of the patients at high risk of endocarditis and to define the characteristics of the patients with methicillin resistant S. aureus (MRSA).

METHODS

We prospectively studied 311 cases of S. aureus bacteremia detected at our hospital during a four-year period.

RESULTS

Nosocomial acquisition of bacteremia was found in 63% of the cases, 45% of which were caused by MRSA. Nosocomial bacteria generally presented in older patients with more severe underlying conditions and a higher prevalence of invasive procedures than patients with the community-acquired disease. Likewise, the primary focus of infection was identifiable in most of the nosocomial episodes and mortality was also higher. Endocarditis presented in 19% of the bacteremia episodes and almost 90% of patients with endocarditis were intravenous drug users (IDU). The risk of endocarditis in this group was 64% whereas it was only 3% in non-IDU patients. Overall mortality was 33% and mortality directly due to the bacteremia was 22%.

CONCLUSIONS

IDU patients were at high risk of endocarditis but most had a favourable outcome. Bacteremia was community-acquired in these patients and they rarely presented MRSA bacteremia. Patients with previous valvular diseases were at high risk of endocarditis and had a high mortality. Non-IDU patients with community-acquired bacteremia were at a low risk of endocarditis, regardless of whether a primary focus of infection had been identified or not. Mortality was lower in this group than in patients with nosocomial bacteremia and there were no cases of MRSA bacteremia. Mortality was higher in patients treated with vancomycin than in patients treated with other antibiotics active against S. aureus.

Regionally specific changes in central brain monoamine levels by 2,4-dichlorophenoxyacetic acid in acute treated rats

As reported in our previous studies, "Serotonin Syndrome", rearing and circling behaviors, were the responses of rats treated with the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) and challenged with amphetamine. An altered serotonergic and dopaminergic system may be responsible for these behaviors. In this work, endogenous levels of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), serotonin (5-HT), and 5-hydroxyindolacetic acid (5-HIAA) were measured in the areas of the mesocortico-limbico and nigrostriatal systems of rats treated with 50 or 100 mg/kg of 2,4-D, but also challenged with amphetamine (5 or 10 mg/kg), in order to determine regional brain contents of biogenic amines and their metabolites and to find a correlation with the behaviors described. The prefrontal cortex (PFc), striatum, nucleus accumbens (NA), midbrain, ventral tegmental area (VTA), substantia nigra (SN) and cerebellum were assayed. The herbicide 2,4-D increased the 5-HT and DA basal levels and these increments were dependent on sex, brain area and 2,4-D doses. The challenge with 5 or 10 mg/kg amphetamine to 2,4-D (50 or 100 mg/kg) treated rats also resulted in an area-, sex- and dose-dependent alterations of the 2,4-D effect on dopaminergic and serotonergic systems. We are demonstrating a correlation between rat behavior altered by the herbicide's treatment and the contents of 5-HT and DA in brain areas, such as PFc, VTA, SN, striatum, NA, midbrain and cerebellum. In order for 2,4-D to produce the neurobehavioral alterations, not only are high levels of 5-HT and DA necessary, but these neurotransmitters must be released.

IL-15 promotes IL-12 production by human monocytes via T cell-dependent contact and may contribute to IL-12-mediated IFN-gamma secretion by CD4+ T cells in the absence of TCR ligation

At inflammatory sites, the number of activated bystander T cells exceeds that of Ag-activated T cells. We investigated whether IL-15, a monocyte-derived cytokine that shares several biologic activities with IL-2, may contribute to bystander T cell activation in the absence of IL-2 and triggering Ag. The addition of IL-15 to cocultures of monocytes and T cells stimulates CD4+ but not CD8+ T cells to produce IFN-gamma. IFN-gamma production requires endogenous IL-12, the production of which in turn is dependent upon CD40/CD154 interactions between CD4+ T cells and monocytes. Indeed, non-TCR-activated CD4+ but not CD8+ T cells express significant levels of CD154. IL-15 may enhance IFN-gamma in this system by up-regulating CD40 expression on monocytes and IL-12Rbeta1 expression on CD4+ T cells. Conversely, using neutralizing anti-IL-15 mAb, we show that the ability of IL-12 to augment IFN-gamma secretion is partly mediated by endogenous IL-15. Finally, in the absence of monocytes, a synergistic effect between exogenous IL-12 and IL-15 is necessary to induce IFN-gamma production by purified CD4+ T cells, while IL-15 alone induces T cell proliferation. It is proposed that this codependence between IL-12 and IL-15 for the activation of inflammatory T cells may be involved in chronic inflammatory disorders that are dominated by a Th1 response. In such a response, a self-perpetuating cycle of inflammation is set forth, because IL-15-stimulated CD4+ T cells may activate monocytes to release IL-12 that synergizes with IL-15 to induce IL-12 response and IFN-gamma production.

Atrial natriuretic factor does not affect norepinephrine catabolism in rat hypothalamus and adrenal medulla

We have previously reported that atrial natriuretic factor (ANF) increases neuronal uptake and endogenous content of norepinephrine (NE) and diminishes neuronal release, synthesis and turn-over of NE in rat hypothalamus and adrenal medulla. The aim of the present work was to study another aspect of NE metabolism and therefore investigate the possible effects of ANF on NE catabolism. The determination of monoamine oxidase (MAO) and catechol-O-methyl transferase (COMT) activity and deaminates metabolites formation were studied in vitro in rat hypothalamus and adrenal medulla slices. Results showed that, in the hypothalamus, 100 nM ANF diminished MAO activity while 10 nM ANF did not modify the enzyme activity. Conversely, 10 and 100 nM ANF reduced MAO activity in adrenal medulla. On the other hand, the atrial factor modified neither COMT activity nor the formation of deaminates metabolites in the hypothalamus and adrenal medulla. Present results as well as previous findings support a putative role for ANF in the modulation of NE metabolism not only in the hypothalamus but also in the adrenal medulla of the rat, affecting the storage, release and uptake of NE but not its catabolism.

Reduced nicotinamide adenine dinucleotide phosphate-diaphorase activity in the paraventricular nucleus of the rat hypothalamus is modulated by estradiol

Based on previous studies demonstrating that reduced nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase (ND) activity is modulated by estradiol and the discovery of a new subtype of estrogen receptor highly expressed in the paraventricular nucleus of the hypothalamus (PVN), a possible estrogen influence on this activity was investigated in the neuronal populations (magno- and parvicellular) of this nucleus. Cryostat sections were cut and processed for the histochemical detection of the ND activity. Following ovariectomy (14 days), numerical data displayed a slight decrease in the number of ND-neurons, especially in the posterior magnocellular and the medial parvicellular subdivisions, which was reversed after daily treatment with estradiol benzoate. Administration of estradiol benzoate to male rats (14 days) induced a significant increase (P < 0.05) in the number of ND-neurons, mainly at the level of the posterior magnocellular subdivision. These data indicate that paraventricular ND-neurons are influenced by estradiol.