Trends in mortality from major cancers in the Americas: 1980-2010.

BACKGROUND: Between the 1970s and 2000 mortality in most of Latin America showed favorable trends for some common cancer sites, including stomach and male lung cancer. However, major concerns were related to mortality patterns from other cancers, particularly in women. We provide an up-to-date picture of patterns and trends in cancer mortality in Latin America. METHODS: We analyzed data from the World Health Organization mortality database in 2005-2009 for 20 cancer sites in 11 Latin American countries and, for comparative purposes, in the USA and Canada. We computed age-standardized (world population) rates (per 100 000 person-year) and provided an overview of trends since 1980 using joinpoint regression models. RESULTS: Cancer mortality from some common cancers (including colorectum and lung) is still comparatively low in Latin America, and decreasing trends continue for other cancer sites (including stomach, uterus, male lung cancers) in several countries. However, there were upward trends for colorectal cancer mortality for both sexes, and for lung and breast cancer mortality in women from most countries. During the last decade, lung cancer mortality in women rose by 1%-3% per year in all Latin American countries except Mexico and Costa Rica, whereas rises of about 1% were registered for breast cancer in Brazil, Colombia and Venezuela. Moreover, high mortality from cancer of the cervix uteri was recorded in most countries, with rates over 13/100 000 women in Cuba and Venezuela. In men, upward trends were registered for prostate cancer mortality in Brazil and Colombia, but also in Cuba, where the rate in 2005-2009 was more than twice that of the USA (23.6 versus 10/100 000). CONCLUSIONS: Tobacco control, efficient screening programs, early cancer detection and widespread access to treatments continue to be a major priority for cancer prevention in most Latin American countries.

Subchronic effects of nasally instilled diesel exhaust particulates on the nasal and airway epithelia in mice.

Diesel exhaust is the major source of ultrafine particles released during traffic-related pollution. Subjects with chronic respiratory diseases are at greater risk for exacerbations during exposure to air pollution. This study evaluated the effects of subchronic exposure to a low-dose of diesel exhaust particles (DEP). Sixty male BALB/c mice were divided into two groups: (a) Saline: nasal instillation of saline (n = 30); and (b) DEP: nasal instillation of 30 microg of DEP/10 microl of saline (n = 30). Nasal instillations were performed 5 days a week, over 30 and 60 days. Animals were anesthetized with pentobarbital sodium (50 mg/kg intraperitoneal [i.p.]) and sacrificed by exsanguination. Bronchoalveolar lavage (BAL) fluid was performed to evaluate the inflammatory cell count and the concentrations of the interleukin (IL)-4, IL-10, and IL-13 by enzyme-linked immunosorbent assay (ELISA). The gene expression of oligomeric mucus/gel-forming (Muc5ac) was evaluated by real-time polymerase chain reaction (PCR). Histological analysis in the nasal septum and bronchioles was used to evaluate the bronchial and nasal epithelium thickness as well as the acidic and neutral nasal mucus content. The saline group (30 and 60 days) did not show any changes in any of the parameters. However, the instillation of DEP over 60 days increased the expression of Muc5ac in the lungs and the acid mucus content in the nose compared with the 30-day treatment, and it increased the total leukocytes in the BAL and the nasal epithelium thickness compared with saline for 60 days. Cytokines concentrations in the BAL were detectable, with no differences among the groups. Our data suggest that a low-dose of DEP over 60 days induces respiratory tract inflammation.

Treatment of hemorrhagic shock with hypertonic saline solution modulates the inflammatory response to live bacteria in lungs

Shock and resuscitation render patients more susceptible to acute lung injury due to an exacerbated immune response to subsequent inflammatory stimuli. To study the role of innate immunity in this situation, we investigated acute lung injury in an experimental model of ischemia-reperfusion (I-R) followed by an early challenge with live bacteria. Conscious rats (N = 8 in each group) were submitted to controlled hemorrhage and resuscitated with isotonic saline (SS, 0.9 percent NaCl) or hypertonic saline (HS, 7.5 percent NaCl) solution, followed by intratracheal or intraperitoneal inoculation of Escherichia coli. After infection, toll-like receptor (TLR) 2 and 4 mRNA expression was monitored by RT-PCR in infected tissues. Plasma levels of tumor necrosis factor α and interleukins 6 and 10 were determined by ELISA. All animals showed similar hemodynamic variables, with mean arterial pressure decreasing to nearly 40 mmHg after bleeding. HS or SS used as resuscitation fluid yielded equal hemodynamic results. Intratracheal E. coli inoculation per se induced a marked neutrophil infiltration in septa and inside the alveoli, while intraperitoneal inoculation-associated neutrophils and edema were restricted to the interseptal space. Previous I-R enhanced lung neutrophil infiltration upon bacterial challenge when SS was used as reperfusion fluid, whereas neutrophil influx was unchanged in HS-treated animals. No difference in TLR expression or cytokine secretion was detected between groups receiving HS or SS. We conclude that HS is effective in reducing the early inflammatory response to infection after I-R, and that this phenomenon is achieved by modulation of factors other than expression of innate immunity components.

Treatment of hemorrhagic shock with hypertonic saline solution modulates the inflammatory response to live bacteria in lungs.

Shock and resuscitation render patients more susceptible to acute lung injury due to an exacerbated immune response to subsequent inflammatory stimuli. To study the role of innate immunity in this situation, we investigated acute lung injury in an experimental model of ischemia-reperfusion (I-R) followed by an early challenge with live bacteria. Conscious rats (N = 8 in each group) were submitted to controlled hemorrhage and resuscitated with isotonic saline (SS, 0.9% NaCl) or hypertonic saline (HS, 7.5% NaCl) solution, followed by intratracheal or intraperitoneal inoculation of Escherichia coli. After infection, toll-like receptor (TLR) 2 and 4 mRNA expression was monitored by RT-PCR in infected tissues. Plasma levels of tumor necrosis factor alpha and interleukins 6 and 10 were determined by ELISA. All animals showed similar hemodynamic variables, with mean arterial pressure decreasing to nearly 40 mmHg after bleeding. HS or SS used as resuscitation fluid yielded equal hemodynamic results. Intratracheal E. coli inoculation per se induced a marked neutrophil infiltration in septa and inside the alveoli, while intraperitoneal inoculation-associated neutrophils and edema were restricted to the interseptal space. Previous I-R enhanced lung neutrophil infiltration upon bacterial challenge when SS was used as reperfusion fluid, whereas neutrophil influx was unchanged in HS-treated animals. No difference in TLR expression or cytokine secretion was detected between groups receiving HS or SS. We conclude that HS is effective in reducing the early inflammatory response to infection after I-R, and that this phenomenon is achieved by modulation of factors other than expression of innate immunity components.

Early short-term versus prolonged low-dose methylprednisolone therapy in acute lung injury.

The present study compared the effects of early short-term with prolonged low-dose corticosteroid therapy in acute lung injury (ALI). In total, 120 BALB/c mice were randomly divided into five groups. In the control group, saline was intratracheally (i.t.) instilled. In the ALI group, mice received Escherichia coli lipopolysaccharide (10 microg i.t.). ALI animals were further randomised into four subgroups to receive saline (0.1 mL i.v.) or methylprednisolone (2 mg x kg(-1) i.v.) at 6 h, 24 h or daily (for 7 days, beginning at day 1). At 1, 3 and 8 weeks, in vivo and in vitro lung mechanics and histology (light and electron microscopy), collagen and elastic fibre content, cytokines in bronchoalveolar lavage fluid and the expression of matrix metalloproteinase (MMP)-9 and -2 were measured. In vivo (static elastance and viscoelastic pressure) and in vitro (tissue elastance and resistance) lung mechanics, alveolar collapse, cell infiltration, collagen and elastic fibre content and the expression of MMP-9 and MMP-2 were increased in ALI at 1 week. Methylprednisolone led to a complete resolution of lung mechanics, avoided fibroelastogenesis and the increase in the expression of MMP-9 and MMP-2 independent of steroid treatment design. Thus, early short-term, low-dose methylprednisolone is as effective as prolonged therapy in acute lung injury.

Noninvasive ventilation in immunocompromised pediatric patients: eight years of experience in a pediatric oncology intensive care unit

The experience of noninvasive positive pressure ventilation (NPPV) in the pediatric setting is limited. The aim of the present study is to retrospectively evaluate the effectiveness of NPPV in pediatric immunocompromised patient admitted in our PICU (Pediatric Intensive Care Unit) for acute respiratory failure. Retrospective cohort study of children admitted to the PICU of Hospital do Cancer between June 1997 and May 2005 requiring ventilatory support. A total of 239 admissions were included. The first mechanical ventilation (MV) technique used was NPPV in 120 (50.2%) patients [noninvasive ventilation (NIV) group] and conventional MV in 119 (49.8%) [invasive ventilation (IV) group]; 25.8% of the patients from the NIV group subsequently required intubation. Patients in the IV group were more likely to be in a severe clinical status. Characteristics associated with severe clinical status were median value for therapeutic intervention scoring system score (37.5 points IV vs. 29 points NIV, P2 organs failure (63.6% IV vs. 36.4% NIV, Por=40 points (P=0.018). Our results encourage the use of NPPV as a first-line treatment in children with malignancies who develops acute respiratory failure, except in those with severe hemodynamic status.

Protective effects of phosphodiesterase inhibitors on lung function and remodeling in a murine model of chronic asthma.

The aim of the present study was to compare the efficacy of a novel phosphodiesterase 4 and 5 inhibitor, LASSBio596, with that of dexamethasone in a murine model of chronic asthma. Lung mechanics (airway resistance, viscoelastic pressure, and static elastance), histology, and airway and lung parenchyma remodeling (quantitative analysis of collagen and elastic fiber) were analyzed. Thirty-three BALB/c mice were randomly assigned to four groups. In the asthma group (N = 9), mice were immunized with 10 microg ovalbumin (OVA, ip) on 7 alternate days, and after day 40 they were challenged with three intratracheal instillations of 20 microg OVA at 3-day intervals. Control mice (N = 8) received saline under the same protocol. In the dexamethasone (N = 8) and LASSBio596 (N = 8) groups, the animals of the asthma group were treated with 1 mg/kg dexamethasone disodium phosphate (0.1 mL, ip) or 10 mg/kg LASSBio596 dissolved in dimethyl sulfoxide (0.2 mL, ip) 24 h before the first intratracheal instillation of OVA, for 8 days. Airway resistance, viscoelastic pressure and static elastance increased significantly in the asthma group (77, 56, and 76%, respectively) compared to the control group. The asthma group presented more intense alveolar collapse, bronchoconstriction, and eosinophil and neutrophil infiltration than the control group. Both LASSBio596 and dexamethasone inhibited the changes in lung mechanics, tissue cellularity, bronchoconstriction, as well as airway and lung parenchyma remodeling. In conclusion, LASSBio596 at a dose of 10 mg/kg effectively prevented lung mechanical and morphometrical changes and had the potential to block fibroproliferation in a BALB/c mouse model of asthma.

Protective effects of phosphodiesterase inhibitors on lung function and remodeling in a murine model of chronic asthma

The aim of the present study was to compare the efficacy of a novel phosphodiesterase 4 and 5 inhibitor, LASSBio596, with that of dexamethasone in a murine model of chronic asthma. Lung mechanics (airway resistance, viscoelastic pressure, and static elastance), histology, and airway and lung parenchyma remodeling (quantitative analysis of collagen and elastic fiber) were analyzed. Thirty-three BALB/c mice were randomly assigned to four groups. In the asthma group (N = 9), mice were immunized with 10 æg ovalbumin (OVA, ip) on 7 alternate days, and after day 40 they were challenged with three intratracheal instillations of 20 æg OVA at 3-day intervals. Control mice (N = 8) received saline under the same protocol. In the dexamethasone (N = 8) and LASSBio596 (N = 8) groups, the animals of the asthma group were treated with 1 mg/kg dexamethasone disodium phosphate (0.1 mL, ip) or 10 mg/kg LASSBio596 dissolved in dimethyl sulfoxide (0.2 mL, ip) 24 h before the first intratracheal instillation of OVA, for 8 days. Airway resistance, viscoelastic pressure and static elastance increased significantly in the asthma group (77, 56, and 76 percent, respectively) compared to the control group. The asthma group presented more intense alveolar collapse, bronchoconstriction, and eosinophil and neutrophil infiltration than the control group. Both LASSBio596 and dexamethasone inhibited the changes in lung mechanics, tissue cellularity, bronchoconstriction, as well as airway and lung parenchyma remodeling. In conclusion, LASSBio596 at a dose of 10 mg/kg effectively prevented lung mechanical and morphometrical changes and had the potential to block fibroproliferation in a BALB/c mouse model of asthma.

A simple method for the differential characterization of alveoli and alveolar ducts in injured lungs.

RATIONALE AND HYPOTHESIS: Previous studies evaluating the histoarchitecture of distal airspaces have been shown to be limited by the difficulty in adequately differentiating alveoli and alveolar ducts. This limitation has been specially noticed in studies addressing lung recruitment and in situations of diffuse alveolar damage (DAD), where generic nominations for distal airspaces had to be created, such as "peripheral airspaces" (PAS) and "large-volume gas-exchanging airspaces" (LVGEA). Elastic stains have been largely used to describe normal lung structures. Weigert's resorcin-fuchsin staining (WRF) demarcates the thickened free portions of the ductal septum facilitating its recognition. We hypothesized that this staining could help in differentiating alveoli from alveolar ducts in distorted lung parenchyma. MATERIAL AND METHODS: Samples of control lungs and of DAD lungs induced by mechanical ventilation (VILI) were stained with hematoxylin-eosin (HE) and with WRF. Using morphometry we assessed the volume proportion of alveoli, alveolar ducts and LVGEA in control and VILI lungs. RESULTS: WRF stained VILI lungs showed a significant decrease in the volume proportion of LVGEA and alveoli and a significant increase in the volume proportion of alveolar ducts when compared to HE stained samples. CONCLUSION: We conclude that WRF staining is useful to distinguish alveolar ducts from alveoli in a DAD model, and suggest that it should be routinely used when morphometric studies of lung parenchyma are performed.

Trends in cancer mortality in Mexico, 1970-1999.

BACKGROUND: Few data on cancer mortality have been published for Mexico over the last few decades. It is therefore of interest to conduct a systematic and updated analysis of cancer mortality in this country. PATIENTS AND METHODS: Age-standardised (world population) mortality rates, at all ages and truncated at age 35-64 years, from major cancers and all cancers combined were computed on the basis of certified deaths derived from the World Health Organization database for the period 1970-99. RESULTS: Mortality rates for all neoplasms showed an upward trend in men of all ages (from 58.2/100,000 in 1970-74 to 87.1/100,000 in 1995-99) and in middle-aged men (from 76.1 to 93.7/100,000, respectively). This reflects the rise until the early 1990s in lung cancer mortality (from 8.1/100,000 in 1970-74 to 15.6/100,000 in 1995-99) and prostate cancer (from 5.5 to 12.2/100,000, respectively). In women, overall mortality rates showed an increase between the early 1970s (75.4/100,000) and the late 1990s (82.3/100,000). Total cancer mortality rates remained low, however, compared with other American countries (e.g. 153.3/100,000 men and 108.6/100,000 women in 1999 in the United States). Truncated rates were stable (126.5/100,000 in 1970-74 and 125.8/100,000 in 1995-99), although they were much higher than overall rates, reflecting exceedingly high rates for uterine (mostly cervical) cancer mortality in middle-aged women (29.5/100,000 in 1995-99). CONCLUSIONS: Total cancer mortality in Mexico has remained comparably low on a worldwide scale, and the upward trends in mortality rates for lung and other tobacco-related neoplasms have tended to level off over the last decade. However, steady rises have been observed for other major cancers, including prostate and breast. Cervical cancer remains a major health problem in women.

Respiratory mechanics and pleural remodelling in pleurodesis induced by barium sulphate.

The aim of this study was to determine whether an intrapleural injection of barium sulphate would produce pleurodesis in rats. Additionally, respiratory mechanics and pleural remodelling were analysed. Single intrapleural injection of barium sulphate (100%) or saline was given to Wistar rats. Respiratory system, lung, and chest wall elastic, resistive and viscoelastic/inhomogeneous pressures were measured by the end-inflation occlusion method at 2 and 30 days after injection. The pleura were examined for gross and histopathological evidence of pleural inflammation and fibrosis, and the underlying lungs were also studied by morphometry. All pulmonary mechanical parameters increased at day 2, but were not different from control at 30 days after injection. Chest wall mechanical parameters did not change. Macroscopic evaluation demonstrated pleural adherence without haemothorax. Histopathologic analysis showed pleural inflammation and fibrosis. There was no alveolar inflammation or fibrosis in both groups. In conclusion, barium sulphate induced pleurodesis with either no changes in respiratory mechanics or lung lesion at day 30.

Effects of propofol on respiratory mechanic and lung histology in normal rats.

BACKGROUND: Propofol is able to reduce airway resistance in lungs with previous airway constriction. The aim of this study was to evaluate the effects of propofol on respiratory mechanics in normal rats and to correlate these parameters with lung histology, to define the sites of action of propofol. METHODS: Sixteen Wistar rats were divided into two groups of eight animals. Rats were sedated (diazepam) and anaesthetized with pentobarbital sodium (C) or propofol (P), and paralysed. Respiratory system, lung, and chest wall resistive, elastic, and viscoelastic/inhomogeneous pressures were computed using the end-inflation occlusion method. RESULTS: Lung resistive pressure was smaller in group P (0.29 kPa (0.05)) than group C (0.37 kPa (0.04)) (P=0.007). The internal diameter of the central airways was greater in group P than C (P=0.01). CONCLUSION: Propofol acts at the airway level decreasing respiratory system and lung impedances as a result of central airway dilation.

Lung tissue mechanics and extracellular matrix remodeling in acute lung injury.

UNLABELLED: This study was undertaken to test whether there is structural remodeling of lung parenchyma that could lead to tissue mechanical changes at an early phase of varying degrees of acute lung injury (ALI). Tissue resistance (R), dynamic elastance (E), and hysteresivity (eta) were analyzed during sinusoidal oscillations of rat lung parenchymal strips 24 h after intraperitoneal injection of saline (C) or paraquat (P [10, 15, 25, and 30 mg/kg]). These strips were also stained in order to quantify the amount of collagen and of three types of elastic fibers (elaunin, oxytalan, and fully developed elastic fibers) in the alveolar septa. E augmented progressively from C to P25, but the data from the P25 and P30 groups were not different (p < 0.0001). R and eta increased from C to P10 and from P15 to P25 (p < 0.001). Collagen fiber content increased exponentially with the severity of the injury. Elaunin and fully developed elastic fibers remained unchanged in the five groups, while oxytalan fibers increased only in the P25 and P30 groups. In conclusion, the pronounced mechanical changes at the tissue level and fibroelastogenesis happened at an early phase of the disease and even in mildly abnormal lung parenchyma. KEYWORDS: elastance; collagen fibers; elastin; paraquat

Morphometric differences in pulmonary lesions in primary and secondary ARDS. A preliminary study in autopsies.

The present study was undertaken in order to describe the morphological differences between pulmonary lesions in acute respiratory distress syndrome originating from direct pulmonary injury (ARDSp) and those originating from extrapulmonary injury (ARDSexp). We investigated a total of 38 ARDS-patients (27 males) ranging in age from 19 to 75 years, classified according to underlying disease in pulmonary (ARDSp) and extrapulmonary disease (ARDSexp). The extent of acute diffuse alveolar damage was assessed morphometrically on histologic gross sections in the upper and lower lobes of one lung. The lesions showed quantitative differences in extent and distribution according to underlying disease (primary pulmonary or secondary involvement). In pulmonary ARDS, a predominance of alveolar collapse (16.6%+/-12.3% versus 10.3%+/-11.9%, p = 0,03), fibrinous exudate (1.7%+/-3.2% versus 0.4%+/-1.1%, p = 0.01) and alveolar wall edema (11.2%+/-7.4% versus 6.6%+/-4.4%, p = 0,05) were found compared to extrapulmonary ARDS. We conclude that the morphology of acute diffuse alveolar damage (DAD) is mainly determined by underlying disease (pulmonary ARDS or extrapulmonary ARDS) differing in quantitative terms within the lung. Physiological, radiographic and respiratory system mechanics differences described in ARDSp and ARDSexp may therefore be due to morphometric differences in pulmonary lesions.

Lung tissue mechanics and extracellular matrix composition in a murine model of silicosis.

The dynamic mechanical properties of lung tissue and its contents of collagen and elastic fibers were studied in strips prepared from mice instilled intratracheally with saline (C) or silica [15 (S15) and 30 days (S30) after instillation]. Resistance, elastance, and hysteresivity were studied during oscillations at different frequencies on S15 and S30. Elastance increased from C to silica groups but was similar between S15 and S30. Resistance was augmented from C to S15 and S30 and was greater in S30 than in S15 at higher frequencies. Hysteresivity was higher in S30 than in C and S15. Silica groups presented a greater amount of collagen than did C. Elastic fiber content increased progressively along time. This increment was related to the higher amount of oxytalan fibers at 15 and 30 days, whereas elaunin and fully developed elastic fibers were augmented only at 30 days. Silicosis led not only to pulmonary fibrosis but also to fibroelastosis, thus assigning a major role to the elastic system in the silicotic lung.

Architectural remodelling in acute and chronic interstitial lung disease: fibrosis or fibroelastosis?

AIMS: Pulmonary fibrosis in acute and chronic lung disease has been much investigated, but little attention has been directed at the elastic tissue in these situations. Our aim was to verify whether elastic deposition accompanies collagen deposition in the repairing process of acute and chronic lung injury. METHODS AND RESULTS: We measured, by image analysis, the content of fibres of the collagenous and elastic systems of the alveolar septum in histological slides sampled from autopsied lungs, using the picrosirius-polarization method and Weigert's resorcin-fuchsin stain, respectively. Five groups were studied: I, 10 normal patients; II, 10 patients with cardiogenic pulmonary oedema; III, 23 adult respiratory distress syndrome (ARDS) patients in the early phase; IV, 14 ARDS patients in the late fibroproliferative phase; and V, 10 idiopathic pulmonary fibrosis patients. The first two groups were used as controls. The content of fibres of the collagenous and elastic systems was significantly increased in groups IV and V as compared to the other groups. CONCLUSIONS: Our results indicate that deposition of elastic system fibres is present in the fibroproliferative phase of ARDS and in usual interstitial pneumonia and suggest that this event may contribute to the alveolar mechanical dysfunction and remodelling that occur in acute and chronic interstitial lung disease.

Impact of BAL in the management of pneumonia with treatment failure: positivity of BAL culture under antibiotic therapy.

BACKGROUND: Pneumonia is responsible for 50% of antibiotics prescribed in ICUs. Treatment failure, ie, absence of improvement or clinical deterioration under antibiotic therapy, presents a dilemma to physicians. BAL is an invasive method validated for etiologic diagnosis in pneumonia. STUDY OBJECTIVE: To evaluate in ICU patients the impact of BAL in the etiologic diagnosis, treatment, and outcome of pneumonia with treatment failure. DESIGN: Prospective clinical study. SETTING: Nonsurgical, medical ICU of a university hospital in Brazil. PATIENTS AND PARTICIPANTS: Sixty-two episodes of pneumonia treated for at least 72 h without clinical improvement in 53 patients hospitalized for diverse clinical emergencies. Mean duration of hospitalization was 14.2 days. Mean duration of previous antibiotic therapy was 11.4 days. INTERVENTIONS: Bronchoscopy and BAL were performed in each episode. BAL fluid was cultivated for aerobic and anaerobic bacteria; the cutoff considered positive was 10(4) cfu/mL; 10(3) cfu/mL was also analyzed if under treatment. Pneumocystis carinii, fungi, Legionella spp, and Mycobacterium spp were also researched. MEASUREMENTS AND RESULTS: Fifty-eight of 62 BAL were performed under antibiotics. The results showed positivity in 45 of 62 (72.6%); 42 of the 45 positive episodes (93.3%) had > 10(4) cfu/mL. The three cases with between 10(3) and 10(4) cfu/mL were considered positive and were treated according to BAL cultures. The main agents were Acinetobacter baumannii (37.1%), Pseudomonas aeruginosa (17.7%), and methicillin-resistant Staphylococcus aureus (MRSA; 16.1%); 46.7% of the episodes (21 of 45) were polymicrobial. BAL results directed a change of therapy in 34 episodes (54.8%). Overall mortality was 43.5%. There was no difference in mortality among positives, negatives, and patients who changed therapy guided by BAL culture. CONCLUSIONS: (1) BAL fluid examination was positive in 45 of 62 episodes (72.6%), with 58 of 62 BAL performed under antibiotics. This suggests that BAL may be a sensitive diagnostic method for treatment failures of clinically diagnosed pneumonias, even if performed under antibiotics; (2) the main pathogens in our study were A baumannii, P aeruginosa, and MRSA, and approximately 45% of infections were polymicrobial; (3) BAL culture results directed a change of therapy in 75.6% of positive episodes (34 of 45) and in 54.8% of all episodes of treatment failure (34 of 62); and (4) there was no difference in mortality among positives, negatives, and patients who changed therapy guided by BAL culture.

Hypomagnesemia in critically ill cancer patients: a prospective study of predictive factors.

Hypomagnesemia is the most common electrolyte disturbance seen upon admission to the intensive care unit (ICU). Reliable predictors of its occurrence are not described. The objective of this prospective study was to determine factors predictive of hypomagnesemia upon admission to the ICU. In a single tertiary cancer center, 226 patients with different diagnoses upon entering were studied. Hypomagnesemia was defined by serum levels <1.5 mg/dl. Demographic data, type of cancer, cause of admission, previous history of arrhythmia, cardiovascular disease, renal failure, drug administration (particularly diuretics, antiarrhythmics, chemotherapy and platinum compounds), previous nutrition intake and presence of hypovolemia were recorded for each patient. Blood was collected for determination of serum magnesium, potassium, sodium, calcium, phosphorus, blood urea nitrogen and creatinine levels. Upon admission, 103 (45.6%) patients had hypomagnesemia and 123 (54.4%) had normomagnesemia. A normal dietary habit prior to ICU admission was associated with normal Mg levels (P = 0.007) and higher average levels of serum Mg (P = 0.002). Postoperative patients (N = 182) had lower levels of serum Mg (0.60 +/- 0.14 mmol/l compared with 0.66 +/- 0.17 mmol/l, P = 0.006). A stepwise multiple linear regression disclosed that only normal dietary habits (OR = 0.45; CI = 0.26-0.79) and the fact of being a postoperative patient (OR = 2.42; CI = 1. 17-4.98) were significantly correlated with serum Mg levels (overall model probability = 0.001). These findings should be used to identify patients at risk for such disturbance, even in other critically ill populations.

Hypomagnesemia in critically ill cancer patients: a prospective study of predictive factors

Hypomagnesemia is the most common electrolyte disturbance seen upon admission to the intensive care unit (ICU). Reliable predictors of its occurrence are not described. The objective of this prospective study was to determine factors predictive of hypomagnesemia upon admission to the ICU. In a single tertiary cancer center, 226 patients with different diagnoses upon entering were studied. Hypomagnesemia was defined by serum levels <1.5 mg/dl. Demographic data, type of cancer, cause of admission, previous history of arrhythmia, cardiovascular disease, renal failure, drug administration (particularly diuretics, antiarrhythmics, chemotherapy and platinum compounds), previous nutrition intake and presence of hypovolemia were recorded for each patient. Blood was collected for determination of serum magnesium, potassium, sodium, calcium, phosphorus, blood urea nitrogen and creatinine levels. Upon admission, 103 (45.6 percent) patients had hypomagnesemia and 123 (54.4 percent) had normomagnesemia. A normal dietary habit prior to ICU admission was associated with normal Mg levels (P = 0.007) and higher average levels of serum Mg (P = 0.002). Postoperative patients (N = 182) had lower levels of serum Mg (0.60 ± 0.14 mmol/l compared with 0.66 ± 0.17 mmol/l, P = 0.006). A stepwise multiple linear regression disclosed that only normal dietary habits (OR = 0.45; CI = 0.26-0.79) and the fact of being a postoperative patient (OR = 2.42; CI = 1.17-4.98) were significantly correlated with serum Mg levels (overall model probability = 0.001). These findings should be used to identify patients at risk for such disturbance, even in other critically ill populations

Trends in cancer mortality in Argentina, 1966-91.

Trends in death certification rates for 12 major cancer sites and total cancer mortality in Argentina were analysed for the period 1966-91 on the basis of the World Health Organization database. In the late 1960s, total cancer mortality rates in Argentina (184/100,000 men, 117/100,000 women, world standard) were among the highest in the world. Over the 25-year period considered, however, cancer mortality in Argentina declined by 15% in both sexes, to reach 157/100,000 in men and 99/100,000 in women, for 1990-91. These rates were somewhat lower than those of North America and, particularly for women, relatively low on a worldwide scale. The favourable trends, observed mostly between the 1960s and the 1980s, reflect the steady decline in gastric cancer rates in both sexes, together with some decline in oesophageal, lung and other tobacco-related neoplasms, mostly in men, following some decline in tobacco consumption over the last two decades. The fall in oesophageal cancer may be related to decreased consumption of hot maté, too. Colorectal cancer rates were high in the 1960s, but declined by 17% in men and 35% in women. An approximately 50% decline was observed for skin cancer mortality, which was among the lowest in the world in the early 1990s, and some decline was observed also for leukaemias and uterine cancer, while breast and prostate neoplasms showed a general stability. The two major unfavourable features of cancer mortality in Argentina were the persistently high rates for oesophageal in men, and for uterine cancer mortality in women. These are likely a result of hot maté drinking for oesophageal cancer and inadequate screening for cervical cancer.