Strain measurement with multiplexed FBG sensor arrays: An experimental investigation

In conventional rock mechanics testing, radial strain measuring devices are usually attached to the sample's surface at its mid-height. Although this procedure provides a realistic picture of the lateral deformation undergone by homogeneous samples, however, this assumption may not be accurate if the tested rock has significant heterogeneity. Fibre Bragg Grating (FBG) sensors have recently been introduced to various rock testing applications due to their versatility over conventional strain gauges and radial cantilevers. FBG sensors have small size, multiplexing capability, and immunity to magnetic interference. The main objective of this study is to explore and understand the capabilities of FBG sensing for strain measurement during rock mechanics testing, including under confining. To do so, two limestone plugs (Savonnières limestone) and one acrylic Poly Methyl Methacrylate (PMMA) plug, all of 38 mm diameter, were prepared. The acrylic plug and one of the Savonnières samples plugs were subjected to Unconfined Compressive Strength (UCS) tests. The second Savonnières plug was subjected to a hydrostatic test up to 20 MPa confining at room temperature. FBG sensors of 125 μm cladding diameter with ceramics (Ormocer) coating were glued on the surface of each sample, spreading across the entire sample's height. Strain gauges and cantilever-type radial gauges were used on the samples submitted to UCS for comparison. Results show that radial strain measurements and calculated elastic properties derived from the FBG readings for samples are comparable to readings from the conventional strain gauges and cantilever-type devices. Apparent bulk moduli based on volumetric strain computed from FBG radial strain readings during the hydrostatic test on the Savonnières sample was consistent with benchtop measurements conducted on the Savonnières sample and another plug extracted from the same parental block, as well as published literature data. Moreover, variations in the calculated elastic properties are interpreted as evidence that the FBG sensors detected heterogeneities in the samples' inner structure, which can be seen in the density profiles computed from x-ray CT images. Such observation confirms the potential of the presented FBG sensors configuration for 3D strain mapping in rock mechanics tests.

Mathematical modeling and computer simulation of needle insertion into soft tissue

In this study we present a kinematic approach for modeling needle insertion into soft tissues. The kinematic approach allows the presentation of the problem as Dirichlet-type (i.e. driven by enforced motion of boundaries) and therefore weakly sensitive to unknown properties of the tissues and needle-tissue interaction. The parameters used in the kinematic approach are straightforward to determine from images. Our method uses Meshless Total Lagrangian Explicit Dynamics (MTLED) method to compute soft tissue deformations. The proposed scheme was validated against experiments of needle insertion into silicone gel samples. We also present a simulation of needle insertion into the brain demonstrating the method's insensitivity to assumed mechanical properties of tissue.

Pore Structure Changes Occur During CO2 Injection into Carbonate Reservoirs

Observations and modeling studies have shown that during CO₂ injection into underground carbonate reservoirs, the dissolution of CO₂ into formation water forms acidic brine, leading to fluid-rock interactions that can significantly impact the hydraulic properties of the host formation. However, the impacts of these interactions on the pore structure and macroscopic flow properties of host rock are poorly characterized both for the near-wellbore region and deeper into the reservoir. Little attention has been given to the influence of pressure drop from the near-wellbore region to reservoir body on disturbing the ionic equilibrium in the CO₂-saturated brine and consequent mineral precipitation. In this paper, we present the results of a novel experimental procedure designed to address these issues in carbonate reservoirs. We injected CO₂-saturated brine into a composite core made of two matching grainstone carbonate core plugs with a tight disk placed between them to create a pressure profile of around 250 psi resembling that prevailing in reservoirs during CO₂ injection. We investigated the impacts of fluid-rock interactions at pore and continuum scale using medical X-ray CT, nuclear magnetic resonance, and scanning electron microscopy. We found that strong calcite dissolution occurs near to the injection point, which leads to an increase in primary intergranular porosity and permeability of the near injection region, and ultimately to wormhole  formation. The strong heterogeneous dissolution of calcite grains leads to the formation of intra-granular micro-pores. At later stages of the dissolution, the internal regions of ooids become accessible to the carbonated brine, leading to the formation of moldic porosity. At distances far from the injection point, we observed minimal or no change in pore structure, pore roughness, pore populations, and rock hydraulic properties. The pressure drop of 250 psi slightly disturbed the chemical equilibrium of the system, which led to minor precipitation of sub-micron sized calcite crystals but due to the large pore throats of the rock, these deposits had no measurable impact on rock permeability. The trial illustrates that the new procedure is valuable for investigating fluid-rock interactions by reproducing the geochemical consequences of relatively steep pore pressure gradients during CO₂ injection.

Detection of incident breast and colorectal cancer cases from an administrative healthcare database in Catalonia, Spain

OBJECTIVE

To validate the Catalan minimum basic data set (MBDS) of hospital discharges as an information source for detecting incident breast (BC) and colorectal cancer (CRC), against the Hospital del Mar Cancer Registry (RTHMar) in Barcelona (Spain) as the gold standard.

METHODS

Using ASEDAT software (Analysis, Selection and Extraction of Tumour Data), we identified Catalan public hospital discharge abstracts in patients with a first-time diagnosis of BC and CRC in the years 2005, 2008, and 2011, aggregated by unique patient identifiers and sorted by date. Once merged with the RTHMar database and anonymized, tumour-specific algorithms were validated to extract data on incident cases, tumour stage, surgical treatment, and date of incidence.

RESULTS

MBDS had a respective sensitivity and positive predictive value (PPV) of 78.0% (564/723) and 90.5% (564/623) for BC case detection; and 83.9% (387/461) and 94.9% (387/408) for CRC case detection. The staging algorithms overestimated the proportion of local-stage cases and underestimated the regional-stage cases in both cancers. When loco-regional stage and surgery were combined, sensitivity and PPV reached 98.3% and 99.8%, respectively, for BC and 96.4% and 98.4% for CRC. The differences between dates of incidence between RTHMar and MBDS were greater for BC cases without initial surgery, whereas they were generally smaller and homogeneous for CRC cases.

CONCLUSIONS

The MBDS is a valid and efficient instrument to improve the completeness of a hospital-based cancer registry (HBCR), particularly in BC and CRC, which require hospitalization and are predominantly surgical.

Reoperations after primary breast conserving surgery in women with invasive breast cancer in Catalonia, Spain: a retrospective study

BACKGROUND

Although complete tumor resection is accepted as the best means to reduce recurrence, reoperations after lumpectomy are a common problem in breast cancer. The aim of this study was to assess the reoperation rates after primary breast conserving surgery in invasive breast cancer cases diagnosed in Catalonia, Spain, between 2005 and 2011 and to identify variations based on patient and tumour characteristics.

METHODS

Women with invasive incident breast cancer identified from the Patient's Hospital Discharge Database [174.0-174.9 codes of the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) as the primary diagnosis] and receiving primary breast conserving surgery were included in the study and were followed up to 3 and 12 months by collecting information about repeat breast cancer surgery.

RESULTS

Reoperation rates after primary breast conserving surgery decreased from 13.0 % in 2005 to 11.7 % in 2011 at 3 months and from 14.2 % in 2005 to 12.9 % in 2011 at 12 months' follow-up. While breast conservation reoperations saw a slight, non-significant increase in the same period (from 5.7 to 7.3 % at 3 months, and from 6.0 to 7.5 % at 12 months), there was a significant decrease in radical reoperation (from 7.3 to 4.4 % at 3 months and from 8.2 to 5.4 % at 12 months). Overall, additional breast surgeries decreased among younger women.

CONCLUSIONS

Despite the rise of breast conserving surgery, reoperation rates following initial lumpectomy in Catalonia decreased by 10 % at 3 and 12 months' follow-up, remaining low and almost unchanged. Ultimately, there was also a significant decrease in mastectomies.

New Results from the Search for Low-Mass Weakly Interacting Massive Particles with the CDMS Low Ionization Threshold Experiment

The CDMS low ionization threshold experiment (CDMSlite) uses cryogenic germanium detectors operated at a relatively high bias voltage to amplify the phonon signal in the search for weakly interacting massive particles (WIMPs). Results are presented from the second CDMSlite run with an exposure of 70 kg day, which reached an energy threshold for electron recoils as low as 56 eV. A fiducialization cut reduces backgrounds below those previously reported by CDMSlite. New parameter space for the WIMP-nucleon spin-independent cross section is excluded for WIMP masses between 1.6 and 5.5  GeV/c^{2}.

Characterization of Darai Limestone Composition and Porosity Using Data-Constrained Modeling and Comparison with Xenon K-Edge Subtraction Imaging

Data-constrained modeling is a method that enables three-dimensional distribution of mineral phases and porosity in a sample to be modeled based on micro-computed tomography scans acquired at different X-ray energies. Here we describe an alternative method for measuring porosity, synchrotron K-edge subtraction using xenon gas as a contrast agent. Results from both methods applied to the same Darai limestone sample are compared. Reasonable agreement between the two methods and with other porosity measurements is obtained. The possibility of a combination of data-constrained modeling and K-edge subtraction methods for more accurate sample characterization is discussed.

First direct limits on lightly ionizing particles with electric charge less than e/6

While the standard model of particle physics does not include free particles with fractional charge, experimental searches have not ruled out their existence. We report results from the Cryogenic Dark Matter Search (CDMS II) experiment that give the first direct-detection limits for cosmogenically produced relativistic particles with electric charge lower than e/6. A search for tracks in the six stacked detectors of each of two of the CDMS II towers finds no candidates, thereby excluding new parameter space for particles with electric charges between e/6 and e/200.

Central nervous system involvement in adult patients with invasive infection caused by Streptococcus agalactiae

INTRODUCTION

Streptococcus agalactiae is frequently an asymptomatic coloniser and a cause of neonatal and puerperal sepsis. Infections in nonpregnant adults are uncommon. The frequency of neurological complications caused by invasive infection with this microorganism in adults remains unknown. Here, we study the frequency and characteristics of central nervous system (CNS) involvement in adults with invasive S. agalactiae infection.

PATIENTS AND METHODS

Review of all adults with invasive S. agalactiae infection between 2003 and 2011 in a tertiary hospital.

RESULTS

S. agalactiae was isolated from blood, CSF or synovial fluid in 75 patients. Among them, 7 (9,3%) displayed neurological involvement: 5 men and 2 nonpregnant women, aged between 20 and 62 years. Diagnoses were spinal epidural abscess due to spondylodiscitis with spinal cord compression; acute bacterial meningitis; ischemic stroke as presentation of bacterial endocarditis (2 patients each); and meningoventriculitis after neurosurgery and ventricular shunting. One patient with endocarditis caused by S. agalactiae and S. aureus died in the acute phase, and another died 3 months later from metastatic cancer. The other patients recovered without sequelae. All patients had systemic predisposing factors for infection and 5 (71,4%) had experienced disruption of the mucocutaneous barrier as a possible origin of the infection.

CONCLUSIONS

CNS involvement is not uncommon in adult patients with invasive infection caused by S. agalactiae. Isolating S. agalactiae, especially in cases of meningitis, should lead doctors to search for predisposing systemic disease and causes of mucocutaneous barrier disruption.

Search for low-mass weakly interacting massive particles with SuperCDMS

We report a first search for weakly interacting massive particles (WIMPs) using the background rejection capabilities of SuperCDMS. An exposure of 577 kg days was analyzed for WIMPs with mass <30  GeV/c(2), with the signal region blinded. Eleven events were observed after unblinding. We set an upper limit on the spin-independent WIMP-nucleon cross section of 1.2×10(-42)  cm(2) at 8  GeV/c(2). This result is in tension with WIMP interpretations of recent experiments and probes new parameter space for WIMP-nucleon scattering for WIMP masses <6  GeV/c(2).

Search for low-mass weakly interacting massive particles using voltage-assisted calorimetric ionization detection in the SuperCDMS experiment

SuperCDMS is an experiment designed to directly detect weakly interacting massive particles (WIMPs), a favored candidate for dark matter ubiquitous in the Universe. In this Letter, we present WIMP-search results using a calorimetric technique we call CDMSlite, which relies on voltage-assisted Luke-Neganov amplification of the ionization energy deposited by particle interactions. The data were collected with a single 0.6 kg germanium detector running for ten live days at the Soudan Underground Laboratory. A low energy threshold of 170  eVee (electron equivalent) was obtained, which allows us to constrain new WIMP-nucleon spin-independent parameter space for WIMP masses below 6  GeV/c2.

Silicon detector dark matter results from the final exposure of CDMS II

We report results of a search for weakly interacting massive particles (WIMPS) with the silicon detectors of the CDMS II experiment. This blind analysis of 140.2 kg day of data taken between July 2007 and September 2008 revealed three WIMP-candidate events with a surface-event background estimate of 0.41(-0.08)(+0.20)(stat)(-0.24)(+0.28)(syst). Other known backgrounds from neutrons and 206Pb are limited to <0.13 and <0.08 events at the 90% confidence level, respectively. The exposure of this analysis is equivalent to 23.4 kg day for a recoil energy range of 7-100 keV for a WIMP of mass 10  GeV/c2. The probability that the known backgrounds would produce three or more events in the signal region is 5.4%. A profile likelihood ratio test of the three events that includes the measured recoil energies gives a 0.19% probability for the known-background-only hypothesis when tested against the alternative WIMP+background hypothesis. The highest likelihood occurs for a WIMP mass of 8.6  GeV/c2 and WIMP-nucleon cross section of 1.9×10(-41)  cm2.

Cancer incidence and mortality projections up to 2020 in Catalonia by means of Bayesian models

PURPOSE

To predict the burden of cancer in Catalonia by 2020 assessing changes in demography and cancer risk during 2010-2020.

METHODS/PATIENTS

Data were obtained from Tarragona and Girona cancer registries and Catalan mortality registry. Population age distribution was obtained from the Catalan Institute of Statistics. Predicted cases in Catalonia were estimated through autoregressive Bayesian age-period-cohort models.

RESULTS

There will be diagnosed 26,455 incident cases among men and 18,345 among women during 2020, which means an increase of 22.5 and 24.5 % comparing with the cancer incidence figures of 2010. In men, the increase of cases (22.5 %) can be partitioned in three components: 12 % due to ageing, 8 % due to increase in population size and 2 % due to cancer risk. In women, the role of each component was 9, 8 and 8 %, respectively. The increased risk is mainly expected to be observed in tobacco-related tumours among women and in colorectal and liver cancers among men. During 2010-2020 a mortality decline is expected in both sexes.

CONCLUSION

The expected increase of cancer incidence, mainly due to tobacco-related tumours in women and colorectal in men, reinforces the need to strengthen smoking prevention and the expansion of early detection of colorectal cancer in Catalonia.

Limbic encephalitis: a clinical-radiological comparison between herpetic and autoimmune etiologies

BACKGROUND

Herpetic (HE) and autoimmune (AE) encephalitis share clinical and radiological features. We compared both types of encephalitis with the aim of making a differential clinical-radiological pattern.

MATERIALS AND METHODS

All cases with a clinical diagnosis of encephalitis who attended our hospital between 1999 and 2012 were reviewed. We selected those cases with positive polymerase chain reaction for herpes simplex virus 1 (HSV-1) in the cerebrospinal fluid (CSF), and those with antineuronal antibodies or paraneoplastic etiology. We compared epidemiological, clinical, CSF, electroencephalographic and radiological findings.

RESULTS

Twelve patients with positive polymerase chain reaction for HSV-1, and 10 patients with antineuronal antibody or paraneoplastic etiology were found. The only features found exclusively in one group were the presence of psychiatric symptoms and tumors in AE. Acute onset of symptoms, fever and aphasia were more frequent in HE, which showed higher level of proteins and erythrocyte count in CSF. Neuroimaging was abnormal in all cases of HE, but only in 60% of AE. Insular and diffuse temporal lobe involvement and absence of basal ganglia involvement were more frequent in HE, and mesial temporal involvement in AE. The highest diagnostic values for differentiating HE from AE were the association of acute onset of symptoms and fever (sensitivity 0.92, specificity 1), and the absence of basal ganglia involvement (sensitivity 0.82, specificity 1).

CONCLUSIONS

There are few differences between HE and AE. Psychiatric symptoms and association with tumors were unique for AE. Acute onset with fever and absence of basal ganglia involvement in magnetic resonance imaging support a diagnosis of HE.

Time trends of cancer incidence and mortality in Catalonia during 1993-2007

PURPOSE

To describe time trends of cancer in Catalonia, Spain, during the period 1993-2007.

METHODS/PATIENTS

Data have been provided by two population-based cancer registries, Girona and Tarragona, and the Catalan mortality registry. Cancer incidence in Catalonia has been estimated through modeling methods using data from these health structures.

RESULTS

During 2003-2007, there were 20,042 cancer cases and 9,842 deaths per year among men and 13,673 new cancer cases and 5,882 deaths among women. The most frequent incident cancers among men were prostate (N = 4,258), lung (N = 3,021), colorectal (N = 3,007) and bladder (N = 2,238), whereas among women they were breast (N = 3,907), colorectal (N = 2,088), corpus uteri (N = 734) and lung (N = 527). During 1993-2007, age-standardized incidence rates (ASIRs) rose 1.2 % per year among men [prostate (6.3 %), testis (5.7 %), kidney (2.9 %), liver (2.2 %) and colorectal (2.1 %)]. ASIRs decreased for stomach (-2.9 %), oral cavity and pharynx (-2.8 %), larynx (-2.7 %) and esophagus (-2 %). Among women, ASIRs only rose for lung (5.2 %), kidney (3.1 %), oral cavity and pharynx (2.6 %) and thyroid (1.6 %). ASIRs decreased for corpus uteri (-2.3 %), stomach (-1.7 %) and ovary (-1.6 %). Cancer mortality decreased -1.3 % per year among men and -2.1 % among women during the same period.

CONCLUSION

Among men, the decrease of incidence/mortality of tobacco-related tumors was related to a reduction of smoking prevalence. Among women, the stabilization of breast cancer incidence and the rise of lung cancer incidence are similar to that observed in most European regions. These results allow assessing the effectiveness of public health strategies and they pose new frontiers for cancer control in Catalonia.

Two color multichannel heterodyne interferometer set up for high spatial resolution electron density profile measurements in TJ-II

A high spatial resolution two color [CO(2), λ=10.6 μm/Nd:YAG (Nd:YAG denotes neodymium-doped yttrium aluminum garnet), and λ=1.064 μm] expanded-beam multichannel heterodyne interferometer has been installed on the TJ-II stellarator. Careful design of the optical system has allowed complete control on the evolution of both Gaussian beams along the interferometer, as well as the evaluation and optimization of the spatial resolution to be expected in the measurements. Five CO(2) (measurement) channels and three Nd:YAG (vibration compensation) channels have been used to illuminate the plasma with a probe beam of 100 mm size. An optimum interpolation method has been applied to recover both interferometric phasefronts prior to mechanical vibration subtraction. The first results of the installed diagnostic are presented in this paper.

House-level risk factors for triatomine infestation in Colombia

BACKGROUND

Chagas disease, transmitted domestically by triatomine bugs, is the most important vector-borne disease in Latin America. The association between triatomine infestation and housing characteristics was investigated based on a standardized survey in 41 971 houses in 15 Departments in Colombia.

METHODS

Multivariate logistic regression was used to test for associations of two highly correlated infestation measures of infestation (householders reporting having seen triatomines inside the house, and sending triatomines to the survey team), with 15 household-level risk factors. Risks were measured relative to a reference category of houses with up to three inhabitants, area up to 50 m(2), unplastered adobe walls, thatch roof and no outbuildings or domestic animals.

RESULTS

The probability of seeing triatomines was highest for households with over seven inhabitants (OR = 1.24, 95% CI 1.11-1.39), overhead storage space (OR = 1.16, 95% CI 1.03-1.32), grain shed (OR = 1.25, 95% CI 1.02-1.52), cats (OR = 1.27, 95% CI 1.14-1.42) and pigs (OR = 1.16, 95% CI 1.03-1.30). Lowest risks were in houses with wooden walls (OR = 0.46, 95% CI 0.34-0.61), fully plastered walls (OR = 0.78, 95% CI 0.68-0.88), roofs made of tiles (OR = 0.51, 95% CI 0.33-0.78) and flagstone floors (OR = 0.57, 95% CI 0.42-0.76). Results for householders returning triatomines support this set of risk factors, but with wider confidence intervals.

CONCLUSIONS

Surveillance of a few easily assessed household characteristics provides an accurate, rapid assessment of house-level variation in risk. Measured effect sizes for specific structural characteristics could be used to maximize the cost-effectiveness of programmes to reduce vector infestation and interrupt Chagas disease transmission by improving house quality.

Time trends of breast cancer mortality in Spain during the period 1977-2001 and Bayesian approach for projections during 2002-2016

BACKGROUND

In recent decades, changes in breast cancer (BC) mortality trends have been observed across Europe. Our objective is to describe BC mortality trend in Spain during 1977-2001 and to estimate BC mortality projection in the period 2002-2016 using a Bayesian approach.

MATERIAL AND METHODS

An age-period-cohort (APC) analysis has been carried out in order to investigate the effect of the age, period and birth cohort on BC mortality in Spain during 1977-2001 and to estimate future trends for the period 2002-2016. A Bayesian APC model with an autoregressive structure for the age parameters has been used for projections of BC mortality.

RESULTS

BC mortality rates increased 2.18% per year during 1977-1991 followed by a significant fall after 1992 (estimated annual percent change = -2.67%; 95% confidence interval = -2.97, -2.31). Cohorts born before 1952 showed higher risk of death from BC than those born after this year. Projections showed an increase of mortality among women older than 50 years in the period 2002-2016 (range of increase = 10%-40%).

CONCLUSIONS

The decrease of BC mortality since 1992 could be attributable to BC down-staging due to early detection and effectiveness of cancer treatment. The effect of ageing on the female population, immigration and the increase of BC incidence observed in Spain could explain the increase in BC mortality predicted for the years to come among women older than 50 years. BC screening to the whole Spanish population and new treatments introduced in the last few years could modify the predictions of BC mortality. Future forecasting studies should be carried out considering these new factors in the natural history of BC in Spain.

1alpha-Hydroxylase transactivation by gamma-interferon in murine macrophages requires enhanced C/EBPbeta expression and activation

gamma-Interferon [gamma-IFN] induction of macrophage 1alpha-hydroxylase mRNA and activity causes severe hypercalcemia in granulomatous disorders. These studies demonstrate transcriptional regulation. gamma-IFN induces the activity of the murine 1alpha-hydroxylase [-1651; +22] promoter in the murine macrophage cell line Raw 264.7 only after a 24h exposure. This slow kinetics is incompatible with classical gamma-IFN-mediated transactivation. In fact, gamma-IFN response mapped to the minimal [-85; +11] promoter, which lacks GAS or ISRE sites but contains a putative C/EBPbeta site. C/EBPbeta is a gamma-IFN inducible gene and a novel mediator of gamma-IFN-regulated transcription. As expected for a C/EBPbeta-driven transcription, ectopic C/EBPbeta expression was sufficient to increase 1alpha-hydroxylase activity, enhance minimal promoter activity and potentiate the induction of this promoter by gamma-IFN. Importantly, the dominant negative C/EBPbeta isoform antagonized C/EBPbeta-transcriptional activity. gamma-IFN induction of C/EBPbeta expression is not sufficient for gamma-IFN induction of minimal promoter activity. There is also a cell-specific induction of C/EBPbeta-transcriptional activity by gamma-IFN. In Raw cells, specific inhibition of gamma-IFN induction of endogenous-C/EBPbeta phosphorylation by MEKK1 markedly reduced basal promoter activity and the response to gamma-IFN. We conclude that gamma-IFN-induction of C/EBPbeta expression and activation by phosphorylation contributes to gamma-IFN-transcriptional control of 1alpha-hydroxylase expression in murine macrophages.

Community-acquired pneumonia in the elderly: Spanish multicentre study

Community-acquired pneumonia (CAP) in the elderly has increased as a consequence of an overall increase of the elderly population. A controversy about the aetiology and outcome of CAP in this population still exists and more epidemiological studies are needed. A prospective, 12-month, multicentre study was carried out to assess the clinical characteristics, aetiology, evolution and prognostic factors of elderly patients (> or = 65 yrs) admitted to hospital for CAP. The study included 503 patients (age 76 +/- 7 yrs). The clinical picture lasted < or = 5 days in 318 (63%) and the main clinical features were cough (n = 407, 81%) and fever (n = 380, 76%). Aetiological diagnosis was achieved in 199 (40%) cases, with a definite diagnosis obtained in 164 (33%). Of the 223 microorganisms isolated the main agents found were Streptococcus pneumoniae in 98 (49%) and Haemophilus influenzae in 27 (14%). A total of 53 patients died (11%) and the multivariate analysis showed the following factors of bad prognosis: previous bed confinement, alteration in mental status, absence of chills, plasma creatinine > or = 1.4 mg x dL(-1), oxygen tension in arterial blood/inspiratorv oxygen fraction ratio < 200 at the time of admission, and shock and renal failure during the evolution. The results of this study may aid in the management of empiric antibiotic treatment in elderly patients with community-acquired pneumonia and the patients who have a greater probability of bad evolution may be identified based on the risk factors.

Comparación entre el análisis automático y manual de la polisomnografía convencional en el diagnóstico del síndrome de apnea-hipopnea obstructiva del sueño

OBJECTIVE

To compare automatic and manual analysis of neurological and respiratory variables obtained with the SomnoStar alpha 4100, a 16-channel polysomnographic system.

PATIENTS AND METHOD

Twenty-eight patients suspected of obstructive sleep apnea-hypopnea syndrome were enrolled and given conventional polysomnographic tests. The order of automatic and manual reading of respiratory episodes, sleep stages, and arousals was randomized. We assessed agreement with the intraclass correlation coefficient and plotted standardized differences against standardized means, using the Bland-Altman method.

RESULTS

Poor agreement was observed between the 2 types of analysis of sleep stages, especially for REM and deep sleep stages. Agreement was good for apneic episodes among the respiratory variables; however, automatic analysis underestimated hypopneas. If manual analysis is considered the gold standard at the apnea-hypopnea index cut point greater than 10, automatic analysis obtained a sensitivity of 55%, a specificity and positive predictive value of 100%, a negative predictive value of 47%, and an overall diagnostic yield of 67.8%.

CONCLUSIONS

The automatic analysis of the SomnoStar 4100 system provides an unsatisfactory reading of sleep stages and respiratory episodes, especially hypopneas.

[The treatment and prognosis of sarcoidosis. Apropos 53]

OBJECTIVE

We retrospectively studied 53 cases of sarcoidosis which have been diagnosed at our service during de last 14 years. The criteria for starting therapy with corticosteroids and recurrences were analyzed.

METHOD

The patients mean (SD) age was 42 (15) years old (range 16-76) and the majority were female (72%). 15 patients (28.3%) received corticosteroids. The only differences with respect to patients not treated were the presence of respiratory symptoms (47% vs 18%; p = 0.04) and the abnormality of spirometric parameters (DLCO/VA p = 0.01; CV p = 0.002).

RESULTS

17 (32%) patients recurred. 14 (82%) of them required corticosteroids. This percentage was significantly greater than that of patients treated at first episode (82% vs 28%, p = 0.0002). All patients improved with treatment. The only difference with respect to patients without recurrences were to be treated at the first episode (53% vs 17%, p = 0.007).

The Sos1 and Sos2 Ras-specific exchange factors: differences in placental expression and signaling properties

Targeted disruption of both alleles of mouse sos1, which encodes a Ras-specific exchange factor, conferred mid-gestational embryonic lethality that was secondary to impaired placental development and was associated with very low placental ERK activity. The trophoblastic layers of sos1(-/-) embryos were poorly developed, correlating with high sos1 expression in wild-type trophoblasts. A sos1(-/-) cell line, which expressed readily detectable levels of the closely related Sos2 protein, formed complexes between Sos2, epidermal growth factor receptor (EGFR) and Shc efficiently, gave normal Ras.GTP and ERK responses when treated with EGF for < or =10 min and was transformed readily by activated Ras. However, the sos1(-/-) cells were resistant to transformation by v-Src or by overexpressed EGFR and continuous EGF treatment, unlike sos1(+/-) or wild-type cells. This correlated with Sos2 binding less efficiently than Sos1 to EGFR and Shc in cells treated with EGF for > or =90 min or to v-Src and Shc in v-Src-expressing cells, and with less ERK activity. We conclude that Sos1 participates in both short- and long-term signaling, while Sos2-dependent signals are predominantly short-term.

Metabolism of the complex monofluorophosphate-alpha 2-macroglobulin in the rat

Sodium monofluorophosphate (MFP) is a drug used in the treatment of primary osteoporosis. Following the intake of MFP, a small fraction of the drug is absorbed intact and forms a complex with alpha 2-macroglobulin (MFP-alpha 2M) inactivating the antiproteasic activity of the globulin. The complex has been shown to occur in the serum of rats and human being. This paper reports data on the metabolism of this complex in the rat. In vitro experiments showed that liver and bone tissue remove MFP-alpha 2M from the incubation medium. When the experiments were pursued beyond the time needed to reduce the complex concentration to very low levels, fluorine (F) reappears in the medium in two forms: bound to low molecular weight macromolecule/s (2,200 +/- 600 Da) and as ionic F. Concentrations of these F fractions increase while that of the complex decreases as a function of time. In vitro, uptake of the complex by liver or bone tissue was not affected by the presence of colchicine or methylamine. These drugs, however, inhibited intracellular metabolism of the complex, as indicated by the impairment of the return of F species to the extracellular space and the increase in F content of the tissue. The cellular receptors responsible for the uptake of the complex in liver and bone are insensitive to low concentration of calcium and inhibited by polyinosinic acid[5']. These features characterize the "scavenger" receptor, one of the two receptor types known to remove inactive alpha 2M from the circulation. Injection of polyinosinic acid [5'] to living rats also hindered the disappearance of the complex from serum. It is concluded that the metabolism of the MFP-alpha 2M complex involves binding to receptors, uptake by cells, lysosomal degradation and return of F bound to low molecular weight macromolecule/s to the extracellular space. It is assumed, however, that inorganic F is the final product of lysosomal hydrolysis of the protein moiety.

Binding of monofluorophosphate to alpha2-macroglobulin and C3

After administering an oral dose of monofluorophosphate (MFP) to human beings or rats, a fraction of the drug appears in plasma that is bound to proteins, establishing a previously undetected compartment of nondiffusible fluoride. This article documents experiments performed in vitro, describing the binding of MFP to two plasma globulins: alpha2-macroglobulin and C3 (a beta-globulin). MFP binds irreversibly to these proteins through a stable bond. MFP binds to purified alpha2-macroglobulin or to C3 with a molar ratio MFP: protein close to unity. MFP binding reduces significantly the biological activity of these proteins, which share in common a macrocyclic 4-residue ring thiolactone (Cys-Gly-Glu-Glu). The binding site of MFP is as yet unknown. Protein-bound MFP appeared in the plasma of volunteers during the 5-7 hours following intake. Peak concentration of protein-bound MFP and maximal reduction of alpha2-macroglobulin activity was observed 2 hours after intake. Clearance of protein-bound MFP coincided with the return of alpha2-macroglobulin to basal levels.

Protected bronchoalveolar lavage in the diagnosis of ventilator-associated pneumonia

The aim of this study was to evaluate the diagnostic efficacy of protected bronchoalveolar lavage (PBAL) in ventilator-associated pneumonia (VAP), and to determine the effect of antibiotic therapy on its microbiological and cytological results. We prospectively studied 102 episodes of suspected VAP in 93 patients. Subsequent follow-up confirmed VAP in 35 of the 102 (34%) cases. In 55 of the 102 (55%) VAP was ruled out, and the diagnosis remained undetermined in 12 of the 102 (12%) episodes. In the VAP group, 30 of the 35 (86%) PBAL (> or = 10(4) colony-forming units (cfu)-mL-1) cultures were positive. In the non-VAP group, 5 of the 55 (9%) PBAL cultures were positive. A Giemsa stain of PBAL samples was performed in 32 of the 35 cases of VAP. Intracellular organisms (ICO) were found in 24 of the 32 (75%) cases. Seven of the other eight cases without evidence of ICO were already on antibiotics. In the non-VAP group, ICO were present in only 1 out of 55 (2%) cases. The mean ICO was significantly higher in the group who had not received antibiotics when compared with those patients previously treated for less than 48 h (p < or = 0.01) and those treated for more than 48 h (p = 0.009). The sensitivity of protected bronchoalveolar lavage quantitative cultures was 87% and the specificity 91%. The sensitivity of cytological analysis for intracellular organisms was 75% and the specificity 98%. According to our results, if the patient is already on antibiotics, the direct examination of protected bronchoalveolar lavage fluid is less reliable, although still helpful.

[Enteral nutrition: reduction in the contamination risk]

Enteral nutrition is used as a routine therapy in patients with caloric-protein malnutrition, severe dysphagia, major burns, intestinal resection, and enterocutaneous fistulae, as long as a portion of the digestive tract still has an active absorptive function. The administration takes place by means of surgical (ostomies) or non-surgical (nasogastric) tubes. In our country, a significant number of hospitalized patients with various diseases receive this type of nutrition. Given that the colonization of the digestive tract by hospital flora is the first step towards developing intra-hospital infections, the contamination implies serious risks. The objective of this study was to study the most appropriate conditions for the manufacturing, storage and administration of the mixture of nutrients of enteral nutrition, to guarantee nutrition with a lower contamination risk. This study was conducted by the Unit of Nutritional Assistance of the Mater Dei Clinic, by means of bacteriological controls, from January 1991 to December 1992, and in 1993 in which the work systematics were reviewed. The study was prospective, and those solutions whose bacteriological counts were lower than 100.000 colony forming units (CFU), and which showed an absence of enteropathological micro-organisms, were considered acceptable, and those solutions which had a bacteriological count greater than or equal to 100.000 CFU and or the presence of enteropathological micro-organisms, were considered unacceptable. During the first period, "usual working conditions", we analyzed the infra-structure, the personnel, the constituents, and the apparatus used in the manufacturing, for which 36 samples were studied at t0 (moment of preparation). Afterwards, in the second period "special working conditions", we analyzed the manufacturing procedures, the storage and the administration of 103 solutions, corresponding to 36 patients, taking samples at t0 and t24 (after 24 hours of preparing). In the first phase, we found a 53% contamination. In the second phase, 99.03% of the solutions were within the limits of acceptability, and only 0.07% were unacceptable. We conclude that it is necessary to have access to a working area which meets the biosecurity norms, to use sterile technique in the preparation, to prefer pharmacologically sterile products for the preparation, to store the prepared mixture between 4 and 8 degrees C, and to keep it cooled during the administration. Lastly, we saw the need to continuously capacitate the nursing, dietary (ABSTRACT TRUNCATED)

Risk factors for the development of Haemophilus influenzae pneumonia in hospitalized adults

Potential risk factors for developing Haemophilus influenzae nosocomial pneumonia have not been sufficiently studied. We wanted to investigate the incidence and risk factors for the development of Haemophilus influenzae pneumonia in the hospital by means of a multivariate analysis. A total of 468 cases of nosocomial pneumonia were observed during the study period, 317 (68%) of which were aetiologically diagnosed by means of highly reliable methods, and H. influenzae was isolated in 57 of them. Fifty of the 57 episodes of H. influenzae pneumonia occurred in mechanically-ventilated patients. Underlying diseases were: medical in 12 cases, surgical in 15 cases, and traumatological in 22. Variables associated with Haemophilus influenzae nosocomial pneumonia in intubated patients after the univariate analysis were: "period between admission and pneumonia 2-7 days" and "no previous antibiotics". A multivariate analysis demonstrated that the variables "no previous antibiotics" and "coma on admission" were risk factors for H. influenzae pneumonia. In nonintubated patients, no risk factors were found for H. influenzae pneumonia compared with other nosocomial pneumonia. We conclude that H. influenzae was involved in 57 out of 317 (18%) of nosocomial pneumonia registered in our institution, and the majority of patients (50 out of 57) were mechanically-ventilated. In this particular subgroup, coma of the patient on admission to hospital and absence of antibiotic treatment prior to developing pneumonia constitute two definite risk factors for developing H. influenzae nosocomial pneumonia.

Risk factors for the development of Haemophilus influenzae pneumonia in hospitalized adults

Potential risk factors for developing Haemophilus influenzae nosocomial pneumonia have not been sufficiently studied. We wanted to investigate the incidence and risk factors for the development of Haemophilus influenzae pneumonia in the hospital by means of a multivariate analysis. A total of 468 cases of nosocomial pneumonia were observed during the study period, 317 (68%) of which were aetiologically diagnosed by means of highly reliable methods, and H. influenzae was isolated in 57 of them. Fifty of the 57 episodes of H. influenzae pneumonia occurred in mechanically-ventilated patients. Underlying diseases were: medical in 12 cases, surgical in 15 cases, and traumatological in 22. Variables associated with Haemophilus influenzae nosocomial pneumonia in intubated patients after the univariate analysis were: "period between admission and pneumonia 2-7 days" and "no previous antibiotics". A multivariate analysis demonstrated that the variables "no previous antibiotics" and "coma on admission" were risk factors for H. influenzae pneumonia. In nonintubated patients, no risk factors were found for H. influenzae pneumonia compared with other nosocomial pneumonia. We conclude that H. influenzae was involved in 57 out of 317 (18%) of nosocomial pneumonia registered in our institution, and the majority of patients (50 out of 57) were mechanically-ventilated. In this particular subgroup, coma of the patient on admission to hospital and absence of antibiotic treatment prior to developing pneumonia constitute two definite risk factors for developing H. influenzae nosocomial pneumonia.

Efficacy, safety, and therapeutic relevance of transthoracic aspiration with ultrathin needle in nonventilated nosocomial pneumonia

In order to determine the potential indications of transthoracic needle aspiration (TNA) using the ultrathin 25G needle for the diagnosis of nonopportunistic lung infections, we prospectively analyzed the diagnostic efficacy, safety, and therapeutic implications of its results in 97 patients with nonventilated nosocomial pneumonias (NVNP). The sensitivity of TNA was 60.9%. Specificity and positive predictive value (PPV) were 100%. Negative predictive value (NPV) was 34.1%. The complications in the studied cases were nil in 89 cases (91.8%), transient hemoptoic expectoration (< 10 ml) in five (5.2%), and self-limited partial pneumothorax in three (3.1%). No complications needing treatment were observed. On the basis of a positive TNA result, the initial antibiotic treatment was modified in 29 of 97 (29.9%) cases. In twelve of these, the empirical antibiotic regimen was demonstrated to be ineffective. We conclude that, using the 25G needle, TNA has a good diagnostic efficacy and is a safe procedure for the etiologic investigation of NVNP. A positive TNA result has significant therapeutic relevance, even in cases where broad-spectrum antibiotics are empirically prescribed.

Branhamella catarrhalis respiratory infections

Branhamella catarrhalis is an aerobic Gram-negative diplococcus. It has been traditionally regarded as an oropharyngeal commensal and until recently was only identified as a pathogen in cases of bronchopulmonary infections. The aim of this study was to analyse the characteristics of the respiratory infections caused by B. catarrhalis and to know the antibiotic susceptibility of this microorganism. We retrospectively studied 32 lower respiratory tract infections, caused by B. catarrhalis (20 cases of bronchial infection and 12 cases of pneumonia), diagnosed between 1988-1989 in our hospital. All patients had an underlying disease; chronic obstructive pulmonary disease (COPD) and chronic heart disease being the most frequent. The aetiological diagnostic procedures were: sputum culture in 28 cases (15 in pure culture and 13 mixed), protected specimen brush (PSB) in three cases and transthoracic needle aspiration (TNA) in one case. Twenty B. catarrhalis isolates were penicillin and ampicillin-resistant, 11 in the pneumonia group and 9 in the bronchial infection group. All isolates were sensitive to amoxycillin-clavulanic acid and second generation cephalosporin. In our group four patients died. We conclude that B. catarrhalis is a not infrequent cause of respiratory infection, particularly in COPD patients, and that the high incidence of antibiotic resistance to penicillin and ampicillin should be taken into account before considering an empirical antibiotic treatment.

Branhamella catarrhalis respiratory infections

Branhamella catarrhalis is an aerobic Gram-negative diplococcus. It has been traditionally regarded as an oropharyngeal commensal and until recently was only identified as a pathogen in cases of bronchopulmonary infections. The aim of this study was to analyse the characteristics of the respiratory infections caused by B. catarrhalis and to know the antibiotic susceptibility of this microorganism. We retrospectively studied 32 lower respiratory tract infections, caused by B. catarrhalis (20 cases of bronchial infection and 12 cases of pneumonia), diagnosed between 1988-1989 in our hospital. All patients had an underlying disease; chronic obstructive pulmonary disease (COPD) and chronic heart disease being the most frequent. The aetiological diagnostic procedures were: sputum culture in 28 cases (15 in pure culture and 13 mixed), protected specimen brush (PSB) in three cases and transthoracic needle aspiration (TNA) in one case. Twenty B. catarrhalis isolates were penicillin and ampicillin-resistant, 11 in the pneumonia group and 9 in the bronchial infection group. All isolates were sensitive to amoxycillin-clavulanic acid and second generation cephalosporin. In our group four patients died. We conclude that B. catarrhalis is a not infrequent cause of respiratory infection, particularly in COPD patients, and that the high incidence of antibiotic resistance to penicillin and ampicillin should be taken into account before considering an empirical antibiotic treatment.