Peripheral and respiratory muscle impairment during murine acute lung injury

Acute respiratory distress syndrome is associated with skeletal muscle compromise, which decreases survival and impairs functional capacity. A comparative analysis of peripheral and respiratory muscles' atrophy and dysfunction in acute lung injury (ALI) has not been performed. We aimed to evaluate diaphragmatic and peripheral muscle mass and contractility in an ALI animal model. ALI was induced in C57BL/6 mice by intratracheal lipopolysaccharides instillation. Muscle mass and in vitro contractility were evaluated at different time points in hindlimb soleus (slow-twitch) and extensor digitorum longus (EDL, fast-twitch), as well as in the main respiratory muscle diaphragm. Myogenic precursor satellite cell-specific transcription factor Pax7 expression was determined by Western blot. Lung injury was associated with atrophy of the three studied muscles, although it was more pronounced and persistent in the diaphragm. Specific contractility was reduced during lung injury in EDL muscle but restored by the time lung injury has resolved. Specific force was not affected in soleus and diaphragm. A persistent increase in Pax7 expression was detected in diaphragm and EDL muscles after induction of ALI, but not in soleus muscle. Different peripheral and respiratory skeletal muscles are distinctly affected during the course of ALI. Each of the studied muscles presented a unique pattern in terms of atrophy development, contractile dysfunction and Pax7 expression.

Musculoskeletal Tumors in Extremities Diagnosed During the Gestational Period: Case Series and Literature Review

Given the low incidence of musculoskeletal tumors during pregnancy, publications on the subject are scarce and treatment guidelines nonexistent. We present five cases of musculoskeletal tumors in pregnant women, three with metastasizing malignant neoplasms and two with aggressive giant cell tumors. The three patients diagnosed during their gestational period were operated before the end of pregnancy, adapting surgical techniques to minimize risk to mother and fetus. Adjuvant therapies were postponed until the end of gestation. All newborns were delivered at term vaginally, except for one where a cesarean section was required. After a mean follow-up of 69.96 months (±56.38), all patients were free of disease, except for the one diagnosed with an extraskeletal myxoid chondrosarcoma who died at 4 years from diagnosis. Surgery plays a key role in the treatment of musculoskeletal tumors diagnosed during pregnancy. These patients must be treated by multidisciplinary teams at sarcoma reference hospitals, involving the obstetrics team in the decision-making process, and adapting each step of the diagnosis and treatment to the gestational period. Key words: pregnancy, musculoskeletal tumors, sarcoma, cancer, oncological surgery.

Pore flow-through catalytic membrane reactor for steam methane reforming: characterization and performance

A new reactor configuration with low Pd loadings allows good methane conversion results at low temperatures.

High CO2 Levels Impair Lung Wound Healing

Delayed lung repair leads to alveolopleural fistulae, which are a major cause of morbidity after lung resections. We have reported that intrapleural hypercapnia is associated with delayed lung repair after lung resection. Here, we provide new evidence that hypercapnia delays wound closure of both large airway and alveolar epithelial cell monolayers because of inhibition of epithelial cell migration. Cell migration and airway epithelial wound closure were dependent on Rac1-GTPase activation, which was suppressed by hypercapnia directly through the upregulation of AMP kinase and indirectly through inhibition of injury-induced NF-κB-mediated CXCL12 (pleural CXC motif chemokine 12) release, respectively. Both these pathways were independently suppressed, because dominant negative AMP kinase rescued the effects of hypercapnia on Rac1-GTPase in uninjured resting cells, whereas proteasomal inhibition reversed the NF-κB-mediated CXCL12 release during injury. Constitutive overexpression of Rac1-GTPase rescued the effects of hypercapnia on both pathways as well as on wound healing. Similarly, exogenous recombinant CXCL12 reversed the effects of hypercapnia through Rac1-GTPase activation by its receptor, CXCR4. Moreover, CXCL12 transgenic murine recipients of orthotopic tracheal transplantation were protected from hypercapnia-induced inhibition of tracheal epithelial cell migration and wound repair. In patients undergoing lobectomy, we found inverse correlation between intrapleural carbon dioxide and pleural CXCL12 levels as well as between CXCL12 levels and alveolopleural leak. Accordingly, we provide first evidence that high carbon dioxide levels impair lung repair by inhibiting epithelial cell migration through two distinct pathways, which can be restored by recombinant CXCL12.

Soft tissue sarcomas in the elbow region and influence of their anatomical features in their treatment. Experience in the Unit of Musculoskeletal Tumours

BACKGROUND AND AIM

Soft tissue sarcomas are exceptionally located in the elbow region. The aim of this work was to study the soft tissue sarcomas of the elbow region, their epidemiological and histopathological characteristics, anatomical features, the treatment performed, and the results obtained, in a unit of musculoskeletal tumours.

METHODS

Retrospective review of ten patients with a mean follow-up of 65.0 ± 11.9 (range 21-132) months with soft tissue sarcomas located in the elbow region operated in our centre between 2008 and 2016.

RESULTS

Mean age was 60.8 ± 6.7 years. Undifferentiated pleomorphic sarcoma was the most frequent histological diagnosis. Limb preservation surgery was performed in 90% of patients. Three patients were previously operated without following surgical oncology guidelines in another hospital, and this was statistically related to the need for more than one surgery to control the disease. R1 margin was obtained in 5 patients and R0 in another 5. Adjuvant radiotherapy was used in 7 cases. In 4 patients, subsequent surgery was performed for local or systemic control of the disease. Local recurrence occurred in 3 cases and in 5 there was distant disease.

CONCLUSION

The elbow region presents difficulty in achieving wide margins due to the proximity of neurovascular structures, adjuvant and / or neoadjuvant therapies could play an important role in performing limb preservation surgery. It would be advisable to refer these tumours to specialized units with multidisciplinary teams.

Complete Blood Count and Derived Indices: Evolution Pattern and Prognostic Value in Adult Burned Patients

Certain parameters of complete blood count (CBC) such as red cell distribution width (RDW) and mean platelet volume, as well as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and RDW-to-platelet ratio (RPR) have been associated with inflammatory status and outcome in diverse medical conditions. The aim of this study was to describe the evolution pattern of these parameters in adult burned patients. Adult burned patients admitted to the National Burn Center in Uruguay between May 2017 and February 2018 (discovery cohort) and between March 2018 and August 2019 (validation cohort) were included. Patients' characteristics and outcomes were recorded, as well as CBC parameters on days 1, 3, 5, and 7 after thermal injury. Eighty-eight patients were included in the discovery cohort. Total body surface area burned was 14 [7-23]% and mortality was 15%. Nonsurvivors presented higher RDW and mean platelet volume (P < .01). NLR decreased after admission in all patients (P < .01), but was higher in nonsurvivors (P < .01). Deceased patients also presented higher RPR on days 3, 5, and 7 (P < .001). On the contrary, PLR was reduced in nonsurvivors (P < .05). There was a significant correlation between NLR on admission and burn extension and severity. Kaplan-Meier analysis revealed that NLR, PLR, and RPR could identify patients with increased mortality. These findings were confirmed in the validation cohort (n = 95). Basic CBC parameters and derived indices could be useful as biomarkers to determine prognosis in adults with thermal injuries.

Mortality analysis of adult burn patients in Uruguay

Objective

To determine the independent risk factors associated with mortality in adult burn patients.

Methods

This was a retrospective, observational study performed at the Centro Nacional de Queimados do Uruguai. All patients with skin burns admitted to the unit since its opening on July 1, 1995 through December 31, 2018 were included. The demographic data, burn profiles, length of stay, mechanical ventilation duration and hospital mortality were studied. A multivariate logistic regression was used to identify the risk factors for mortality. The standardized mortality ratio was calculated by dividing the number of observed deaths by the number of expected deaths (according to the Abbreviated Burn Severity Index).

Results

During the study period, 3,132 patients were included. The median total body surface area burned was 10% (3%-22%). The Abbreviated Burn Severity Index was 6 (4 - 7). Invasive mechanical ventilation was required in 60% of the patients for a median duration of 6 (3 - 16) days. The median length of stay in the unit was 17 (7 - 32) days. The global mortality was 19.9%. Crude mortality and standardized mortality ratio decreased from 1995 through 2018. The global standardized mortality ratio was 0.99. A need for mechanical ventilation (OR 8.80; 95%CI 5.68 - 13.62), older age (OR 1.07 per year; 95%CI 1.06 - 1.09), total body surface area burned (OR 1.05 per 1%; 95%CI 1.03 - 1.08) and extension of third-degree burns (OR 1.05 per 1%; 95%CI 1.03 - 1.07) were independent risk factors for mortality.

Conclusion

The need for mechanical ventilation, older age and burn extension were independent risk factors for mortality in the burned adult Uruguayan population.

Elevated CO2 regulates the Wnt signaling pathway in mammals, Drosophila melanogaster and Caenorhabditis elegans

Carbon dioxide (CO2) is sensed by cells and can trigger signals to modify gene expression in different tissues leading to changes in organismal functions. Despite accumulating evidence that several pathways in various organisms are responsive to CO2 elevation (hypercapnia), it has yet to be elucidated how hypercapnia activates genes and signaling pathways, or whether they interact, are integrated, or are conserved across species. Here, we performed a large-scale transcriptomic study to explore the interaction/integration/conservation of hypercapnia-induced genomic responses in mammals (mice and humans) as well as invertebrates (Caenorhabditis elegans and Drosophila melanogaster). We found that hypercapnia activated genes that regulate Wnt signaling in mouse lungs and skeletal muscles in vivo and in several cell lines of different tissue origin. Hypercapnia-responsive Wnt pathway homologues were similarly observed in secondary analysis of available transcriptomic datasets of hypercapnia in a human bronchial cell line, flies and nematodes. Our data suggest the evolutionarily conserved role of high CO2 in regulating Wnt pathway genes.

Hypercapnia increases airway smooth muscle contractility via caspase-7-mediated miR-133a-RhoA signaling

The elevation of carbon dioxide (CO₂) in tissues and the bloodstream (hypercapnia) occurs in patients with severe lung diseases, including chronic obstructive pulmonary disease (COPD). Whereas hypercapnia has been recognized as a marker of COPD severity, a role for hypercapnia in disease pathogenesis remains unclear. We provide evidence that CO₂ acts as a signaling molecule in mouse and human airway smooth muscle cells. High CO₂ activated calcium-calpain signaling and consequent smooth muscle cell contraction in mouse airway smooth muscle cells. The signaling was mediated by caspase-7-induced down-regulation of the microRNA-133a (miR-133a) and consequent up-regulation of Ras homolog family member A and myosin light-chain phosphorylation. Exposure of wild-type, but not caspase-7-null, mice to hypercapnia increased airway contraction and resistance. Deletion of the Caspase-7 gene prevented hypercapnia-induced airway contractility, which was restored by lentiviral transfection of a miR-133a antagonist. In a cohort of patients with severe COPD, hypercapnic patients had higher airway resistance, which improved after correction of hypercapnia. Our data suggest a specific molecular mechanism by which the development of hypercapnia may drive COPD pathogenesis and progression.

Capturing the multifactorial nature of ARDS - "Two-hit" approach to model murine acute lung injury

Severe acute respiratory distress syndrome (ARDS) presents typically with an initializing event, followed by the need for mechanical ventilation. Most animal models of ALI are limited by the fact that they focus on a singular cause of acute lung injury (ALI) and therefore fail to mimic the complex, multifactorial pathobiology of ARDS. To better capture this scenario, we provide a comprehensive characterization of models of ALI combining two injuries: intra tracheal (i.t.) instillation of LPS or hypochloric acid (HCl) followed by ventilator‐induced lung injury (VILI). We hypothesized, that mice pretreated with LPS or HCl prior to VILI and thus receiving a (“two‐hit injury”) will sustain a superadditive lung injury when compared to VILI. Mice were allocated to following treatment groups: control with i.t. NaCl, ventilation with low peak inspiratory pressure (PIP), i.t. HCl, i.t. LPS, VILI (high PIP), HCl i.t. followed by VILI and LPS i.t. followed by VILI. Severity of injury was determined by protein content and MPO activity in bronchoalveolar lavage (BAL), the expression of inflammatory cytokines and histopathology. Mice subjected to VILI after HCl or LPS instillation displayed augmented lung injury, compared to singular lung injury. However, mice that received i.t. LPS prior to VILI showed significantly increased inflammatory lung injury compared to animals that underwent i.t. HCl followed by VILI. The two‐hit lung injury models described, resulting in additive but differential acute lung injury recaptures the clinical relevant multifactorial etiology of ALI and could be a valuable tool in translational research.

Influenza A Virus Infection Induces Muscle Wasting via IL-6 Regulation of the E3 Ubiquitin Ligase Atrogin-1

Muscle dysfunction is common in patients with adult respiratory distress syndrome and is associated with morbidity that can persist for years after discharge. In a mouse model of severe influenza A pneumonia, we found the proinflammatory cytokine IL-6 was necessary for the development of muscle dysfunction. Treatment with a Food and Drug Administration-approved Ab antagonist to the IL-6R (tocilizumab) attenuated the severity of influenza A-induced muscle dysfunction. In cultured myotubes, IL-6 promoted muscle degradation via JAK/STAT, FOXO3a, and atrogin-1 upregulation. Consistent with these findings, atrogin-1^+/- and atrogin-1^-/- mice had attenuated muscle dysfunction following influenza infection. Our data suggest that inflammatory endocrine signals originating from the injured lung activate signaling pathways in the muscle that induce dysfunction. Inhibiting these pathways may limit morbidity in patients with influenza A pneumonia and adult respiratory distress syndrome.

Respiratory and Peripheral Muscle Assessment in the Intensive Care Unit

Atrophy and weakness of the respiratory and peripheral muscles is a common problem in the intensive care unit (ICU). It is difficult to diagnose, particularly in the early stages of critical disease. Consequently, many cases are detected only in advanced stages, for example, when difficulties in mechanical ventilation weaning are encountered. The aim of this review is to describe the main tools that are currently available for evaluation of peripheral and respiratory muscles in the ICU. Techniques of varying complexity and specificity are discussed, and particular emphasis is placed on those with greater relevance in daily clinical practice, such as ultrasound.

Effects of hypercapnia in acute respiratory distress syndrome

In patients with acute respiratory distress syndrome (ARDS) hypercapnia is a marker of poor prognosis, however there is controversial information regarding the effect of hypercapnia on outcomes. Recently two studies in a large population of mechanical ventilation patients showed higher mortality associated independently to hypercapnia. Key roles responsible for the poor clinical outcomes observed in critically ill patients exposed to hypercapnia are not well known, two possible mechanisms involved are the effect of CO2 on the muscle and the alveolar epithelium. Hypercapnia frequently coexists with muscle atrophy and dysfunction, moreover patients surviving ARDS present reduced muscle strength and decreased physical quality of life. One of the possible mechanisms responsible for these abnormalities could be the effects of hypercapnia during the course of ARDS. More over controversy persists about the hypercapnia role in the alveolar space, in the last years there is abundant experimental information on its deleterious effects on essential functions of the alveolar epithelium.

Effects of early hemodynamic resuscitation on left ventricular performance and microcirculatory function during endotoxic shock

Background

Microcirculation and macrohemodynamics are severely compromised during septic shock. However, the relationship between these two compartments needs to be further investigated. We hypothesized that early resuscitation restores left ventricular (LV) performance and microcirculatory function but fails to prevent metabolic disorders. We studied the effects of an early resuscitation protocol (ERP) on LV pressure/volume loops-derived parameters, sublingual microcirculation, and metabolic alterations during endotoxic shock.

Methods

Twenty-five pigs were randomized into three groups: LPS group: Escherichia coli lipopolysaccharide (LPS); ERP group: LPS + ERP based on volume expansion, dobutamine, and noradrenaline infusion; Sham group. LV pressure/volume-derived parameters, systemic hemodynamics, sublingual microcirculation, and metabolic profile were assessed at baseline and after completing the resuscitation protocol.

Results

LPS significantly decreased LV end-diastolic volume, myocardial contractility, stroke work, and cardiac index (CI). Early resuscitation preserved preload, and myocardial contractility, increased CI and heart rate (p < .05). LPS severely diminished sublingual microvascular flow index (MFI), perfused vascular density (PVD), and the proportion of perfused vessels (PPV), while increased the heterogeneity flow index (HFI) (p < .05). Despite MFI was relatively preserved, MVD, PVD, and HFI were significantly impaired after resuscitation (p < .05). The macro- and microcirculatory changes were associated with increased lactic acidosis and mixed venous O₂ saturation when compared to baseline values (p < .05). The scatter plot between mean arterial pressure (MAP) and MFI showed a biphasic relationship, suggesting that the values were within the limits of microvascular autoregulation when MAP was above 71 ± 6 mm Hg (R² = 0.63).

Conclusions

Early hemodynamic resuscitation was effective to restore macrohemodynamia and myocardial contractility. Despite MAP and MFI were relatively preserved, the persistent microvascular dysfunction could explain metabolic disorders. The relationship between micro- and systemic hemodynamia and their impact on cellular function and metabolism needs to be further studied during endotoxic shock.

Electronic supplementary material

The online version of this article (doi:10.1186/s40635-015-0049-y) contains supplementary material, which is available to authorized users.

High CO2 levels cause skeletal muscle atrophy via AMP-activated kinase (AMPK), FoxO3a protein, and muscle-specific Ring finger protein 1 (MuRF1)

Patients with chronic obstructive pulmonary disease, acute lung injury, and critical care illness may develop hypercapnia. Many of these patients often have muscle dysfunction which increases morbidity and impairs their quality of life. Here, we investigated whether hypercapnia leads to skeletal muscle atrophy. Mice exposed to high CO2 had decreased skeletal muscle wet weight, fiber diameter, and strength. Cultured myotubes exposed to high CO2 had reduced fiber diameter, protein/DNA ratios, and anabolic capacity. High CO2 induced the expression of MuRF1 in vivo and in vitro, whereas MuRF1(-/-) mice exposed to high CO2 did not develop muscle atrophy. AMP-activated kinase (AMPK), a metabolic sensor, was activated in myotubes exposed to high CO2, and loss-of-function studies showed that the AMPKα2 isoform is necessary for muscle-specific ring finger protein 1 (MuRF1) up-regulation and myofiber size reduction. High CO2 induced AMPKα2 activation, triggering the phosphorylation and nuclear translocation of FoxO3a, and leading to an increase in MuRF1 expression and myotube atrophy. Accordingly, we provide evidence that high CO2 activates skeletal muscle atrophy via AMPKα2-FoxO3a-MuRF1, which is of biological and potentially clinical significance in patients with lung diseases and hypercapnia.

Tandem ATRP/Diels–Alder synthesis of polyHEMA-based hydrogels

An efficient controlled process for the preparation of HEMA-based hydrogels by means of the Diels–Alder reaction.

Role of MicroRNAs in lung disease

MicroRNAs (miRNAs) are small non-coding RNA molecules that negatively regulate gene expression. They actively participate in the modulation of important cell physiological processes and are involved in the pathogenesis of lung diseases such as lung cancer, pulmonary fibrosis, asthma and chronic obstructive pulmonary disease. A better understanding of the role that miRNAs play in these diseases could lead to the development of new diagnostic and therapeutic tools. In this review, we discuss the role of some miRNAs in different lung diseases as well as the possible future of these discoveries in clinical applications.

Validity of ultrasonography and measures of adult shoulder function and reliability of ultrasonography in detecting shoulder synovitis in patients with rheumatoid arthritis using magnetic resonance imaging as a gold standard

OBJECTIVE

To assess the intra- and interobserver reproducibility of musculoskeletal ultrasonography (US) in detecting inflammatory shoulder changes in patients with rheumatoid arthritis, and to determine the agreement between US and the Shoulder Pain and Disability Index (SPADI) and the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, using magnetic resonance imaging (MRI) as a gold standard.

METHODS

Eleven rheumatologists investigated 10 patients in 2 rounds independently and blindly of each other by US. US results were compared with shoulder function tests and MRI.

RESULTS

The positive and negative predictive values (NPVs) for axillary recess synovitis (ARS) were 0.88 and 0.43, respectively, for posterior recess synovitis (PRS) were 0.36 and 0.97, respectively, for subacromial/subdeltoid bursitis (SASB) were 0.85 and 0.28, respectively, and the NPV for biceps tenosynovitis (BT) was 1.00. The intraobserver kappa was 0.62 for ARS, 0.59 for PRS, 0.51 for BT, and 0.70 for SASB. The intraobserver kappa for power Doppler US (PDUS) signal was 0.91 for PRS, 0.77 for ARS, 0.94 for SASB, and 0.53 for BT. The interobserver maximum kappa was 0.46 for BT, 0.95 for ARS, 0.52 for PRS, and 0.61 for SASB. The interobserver reliability of PDUS was 1.0 for PRS, 0.1 for ARS, 0.5 for BT, and 1.0 for SASB. P values for the SPADI and DASH versus cuff tear on US were 0.02 and 0.01, respectively; all other relationships were not significant.

CONCLUSION

Overall agreements between gray-scale US and MRI regarding synovitis of the shoulder varied considerably, but excellent results were seen for PDUS. Measures of shoulder function have a poor relationship with US and MRI. Improved standardization of US scanning technique could further reliability of shoulder US.

[Salbutamol improves diaphragmatic contractility in chronic airway obstruction]

INTRODUCTION

Chronic airflow obstruction in conditions such as chronic obstructive pulmonary disease is associated with respiratory muscle dysfunction. Our aim was to study the effects of salbutamol-a beta-adrenergic agonist known to improve muscle strength in physiologic and pathologic conditions-on diaphragm contractility in an animal model of chronic airway obstruction achieved by tracheal banding.

MATERIALS AND METHODS

Twenty-four Sprague-Dawley rats were randomized into a control group and 3 tracheal banding groups, 1 that received acute salbutamol treatment, 1 that received chronic salbutamol treatment, and 1 that received nothing. Arterial blood gases, acid-base balance, and in vitro diaphragmatic contractility were evaluated by measuring peak twitch tension, contraction time, contraction velocity, half-relaxation time, relaxation velocity, and force-frequency curves.

RESULTS

The 3 study groups had significantly reduced arterial pH and increased PaCO2 and bicarbonate levels compared to the control group (P<.05). The untreated tracheal banding group had significantly reduced peak twitch tension and contraction velocity, and a significantly lower force-frequency curve in comparison with the other groups (P<.05). The chronic treatment group had a higher relaxation velocity than the untreated study group (P<.05). The mean (SE) peak twitch tension values were 6.46 (0.90)N/cm(2) for the control group, 3.28 (0.55)N/cm(2) for the untreated tracheal banding group, 6.18 (0.71)N/cm(2) for the acute treatment group, and 7.09 (0.59)N/cm(2) for the chronic treatment group.

CONCLUSIONS

Diaphragmatic dysfunction associated with chronic airflow obstruction improves with both the acute and chronic administration of salbutamol. The mechanisms involved in respiratory muscle dysfunction warrant further study.

[Salbutamol improves diaphragm force generation in experimental sepsis]

OBJECTIVE

In a high percentage of cases, severe sepsis is accompanied by acute respiratory failure, in which weakness of the respiratory muscles plays an important role. Weakened respiratory muscles that are subjected to an increased mechanical load may develop muscle fatigue, with exacerbation of the respiratory failure. Because beta2-adrenergic drugs increase muscle contraction force, they may play a role in preventing and managing respiratory failure in septic patients. Our aim was to study the effects of salbutamol on diaphragm function in an animal model of peritoneal sepsis.

MATERIAL AND METHODS

The study included 3 groups of animals: a) a control group (n=7), in which the animals underwent a median laparotomy without visceral manipulation; b) a septic group (n=10), in which peritoneal sepsis was induced by cecal ligation and puncture (CLP); and c) a salbutamol group (n=7), in which peritoneal sepsis (CLP) was treated with salbutamol. Hemodynamic parameters and blood gases were measured in vivo. Diaphragm function was evaluated in vitro.

RESULTS

Salbutamol increased aortic blood flow and heart rate while it reduced mean arterial pressure in the animals with peritoneal sepsis (P< .05). Sepsis produced a significant drop in diaphragmatic force both before and after the application of a muscle-fatigue protocol. Treatment with salbutamol improved muscle contraction force before and after application of the protocol (P< .05).

CONCLUSIONS

The use of beta2-adrenergic drugs such as salbutamol improves diaphragm function in experimental sepsis. The mechanisms that produce this improvement require further study.

Analytical diagnosis methodology to evaluate nitrate impact on historical building materials

Nitrate salts have become of greater importance in the decay of materials from historical buildings due to changes in the environment. This work presents an analytical diagnosis methodology to evaluate the impact of nitrate salts in mortars and bricks, combining noninvasive and microdestructive analytical techniques together with chemometric and thermodynamic data analyses. The impact of nitrate salts cannot be well ascertained if other soluble salts are not taken into account. Therefore, the principal results from this work relate to nitrate salts but some results for other kinds of salts are included. Data from Raman microprobe spectroscopy and micro X-ray fluorescence (micro-XRF) are used to characterise the original composition and a first approximation of the nature of the decay compounds, mainly nitrates. The soluble salts are extracted and the anions and cations are quantified by means of ion chromatography with conductimetric detection for anions/cations and inductively coupled plasma mass spectrometry (ICP/MS) for cations. The values obtained allow two different data treatments to be applied. First, chemometric analysis is carried out to search for correlations among anions and cations. Second, thermodynamic modelling with the RUNSALT program is performed to search for environmental conditions of soluble salt formation. All the results are finally used to diagnose the impact of nitrates.

Spectroscopic characterisation of moonmilk deposits in Pozalagua tourist cave (Karrantza, Basque Country, North of Spain)

Composition of moonmilk deposits located in different zones of the tourist Dolomite Cave of Pozalagua (Karrantza, Basque Country, North of Spain) was established by Raman spectroscopy. The deposits were located in column bases and detached rocks near a gour full of water or a dripping zone. Hydromagnesite (Mg(5)(CO(3))(4)(OH)(2).4H(2)O) with a strong Raman band at 1116 cm(-1) and weaker ones at 1522vw, 1487vw, 1452vw, 756w, 727w, 466w, 434w, 371w, 327m, 291w, 258w, 247vw and 230 m cm(-1) was found as the main component of the moonmilk. Aragonite is the unique calcium carbonate compound that sometimes composes the moonmilk but always together with the hydromagnesite. Among non-carbonate minerals, some nitrates (nitrocalcite, niter, nitromagnesite, nitratine and gwihabaite) and sulphates (arkanite) were also identified as minor compounds. Most of the deposits were matt white and pasty, but occasionally some samples appear greyish on the surface. In these samples, carbon particles were also found, apart from the above, and Raman shift changes were observed in the hydromagnesite spectra. Apart from the elements involved in the mentioned minerals, Si, Fe, Mn, Zn and Ti were identified by X-ray microfluorescence as trace elements and the results were correlated with mineral compositions found by Raman measurements. Furthermore, quantification of the soluble salts of moonmilk deposits was carried out by ionic chromatography and the results were chemometrically treated to find correlations among soluble ions and the composition of the mineral phases spectroscopically characterised.

An integrated analytical approach to diagnose the conservation state of building materials of a palace house in the metropolitan Bilbao (Basque Country, North of Spain)

Raman microprobe spectroscopy and microX-ray fluorescence were used to analyse the original composition and degradation products of the limestone and the sandstones from the facades of one historical building. Carbon particles, gypsum (CaSO(4).2H(2)O) and some nitrate compounds were determined by Raman measurements, while elemental characterisation carried out by microXRF revealed the presence of lead, sulphur and copper as pollutants. On the one hand, the grey sandstone is the most deteriorated and in some cases pollutants reach 3 cm depth. On the other hand, quantification of soluble salts (chlorides, sulphates, nitrates, nitrites, fluorides and carbonates) was accomplished by ion chromatography. Chloride and sulphates are not significant soluble salts in the façades of the building, but the amount of nitrate is even 136 g kg(-1) in some of the most deteriorated samples and of 147 g kg(-1) in black-crusts. Finally, organic compounds (mainly PAHs) were characterised by GC-MS. Concentrations higher than 20 ppm of total PAHs were measured in the black-crusts of the rain-protected facades. The presence of certain PAHs indicated combustion of fuels as the main source of deterioration for the palace house building materials.

Analysis of bulk and inorganic degradation products of stones, mortars and wall paintings by portable Raman microprobe spectroscopy

This work reports the use of a portable Raman microprobe spectrometer for the analysis of bulk and decaying compounds in carbonaceous materials such as stones, mortars and wall paintings. The analysed stones include limestone, dolomite and carbonaceous sandstone, gypsum and calcium oxalate, both mono- and dihydrated, being the main inorganic degradation products detected. Mortars include bulk phases with pure gypsum, calcite and mixtures of both or with sand, soluble salts being the most important degradation products. The pigments detected in several wall paintings include Prussian blue, iron oxide red, iron oxide yellow, vermilion, carbon black and lead white. Three different decaying processes have been characterised in the mortars of the wall paintings: (a) a massive absorption of nitrates that reacted with calcium carbonate and promoted the unbinding of pigment grains, (b) the formation of black crusts in the vault of the presbytery and (c) the thermodecomposition of pigments due to a fire.

Nosocomial Kikuchi's disease--a search for herpesvirus sequences in lymph node tissues using PCR

BACKGROUND

Histiocytic necrotizing lymphadenitis, also known as Kikuchi's disease (KD), is a rare disease. Fever and lymphadenopathies with characteristic pathologic features are present. The etiology of this disease remains undetermined. Since the disorder is self-limiting, different viruses have been implicated as the causative agent.

PATIENTS AND METHODS

Seven cases of KD were studied. Three patients acquired the disease nosocomially, three had community-acquired KD and one case was associated with systemic lupus erythematosus. PCR was performed on DNA extracted from lymph node tissues in order to detect herpesvirus-specific DNA sequences: herpes simpLex virus type 1 and 2 (HSV1-2), varicella zoster virus (VZV), human cytomegalovirus (HCMV), human herpesvirus 6 (HHV6), Epstein-Barr virus (EBV) and human herpesvirus 8 (HHV8).

RESULTS

Viral DNA was not detected in any of the lymph node tissues from the seven cases of KD.

CONCLUSION

We conclude that these herpesviruses were not involved in the etiology of the three cases of nosocomial KD, nor in the other four cases of KD investigated in this study.

Präder-Willi syndrome fails to alter cardiac autonomic modulation

Twenty-six healthy subjects with a diagnosis of Präder-Willi syndrome were compared with 26 age-, gender-, and body mass index-matched controls for autonomic modulation and baroreflex sensitivity. Electrocardiograms, beat-to-beat finger blood pressures, and respiration were recorded for several minutes in the following sequence: (1) supine, (2) after transition from supine to standing, (3) sitting, (4) during a Valsalva maneuver, (5) while performing moderate exercise, and (6) during recovery from exercise while seated. All recordings were channeled and stored in a computer; analyses were carried out at a later date. Power spectral analysis (fast-Fourier transform) of heart period variability was used to assess cardiac autonomic modulation. The slope of the regression equation between heart period and blood pressure rise after the Valsalva maneuver was used as an index of baroreflex sensitivity. Analysis of variance failed to reveal significant differences in any of the autonomic and baroreflex sensitivity variables between the two groups. Because breathing patterns entrain autonomic modulation, we verified respiration and found no differences between the two groups. Therefore, findings in the current investigation indicate that cardiac autonomic modulation in patients with Präder-Willi syndrome does not differ from age and body mass index-matched subjects.

Dental caries and caries-associated microorganisms in Uruguayan preschool children

The prevalence of dental caries was studied in 3-5-year-old Uruguayan children (n = 76) living in 2 areas with different socioeconomic and cultural conditions. More children from the low socioeconomic area of Las Acacias had caries (68%) than children from the middle- to high-class neighborhood of Pocitos (19%). They also had poorer oral hygiene and a significantly higher caries prevalence (P < 0.05) than those from Pocitos. The occurrence of mutans streptococci and lactobacilli was determined in whole unstimulated saliva and compared with that in debris collected with a loop from the dorsum of the tongue. Mutans streptococci were detected in 42% of the children with significant correlations between the salivary levels of the microorganism and caries experience. Lactobacilli were recovered less frequently (18%). The detection of mutans streptococci in the tongue-loop samples was significantly correlated with that in whole saliva.

Thioredoxin redox control of cell growth and death and the effects of inhibitors

Thioredoxin is a redox protein found over-expressed in some human tumors. Thioredoxin is secreted by tumor cells and stimulates cancer cell growth. Redox activity is essential for growth stimulation by thioredoxin. Cells transfected with thioredoxin cDNA show increased tumor growth and decreased apoptosis in vivo and decreased sensitivity to apoptosis induced by a variety of agents both in vitro and in vivo. Cells transfected with a redox-inactive mutant thioredoxin show inhibited tumor growth in vivo. Thus, thioredoxin offers an attractive target for anticancer drug development. A class of disulfide inhibitors of thioredoxin has been identified. These disulfides inhibit cancer cell growth in culture and have antitumor activity against some human tumor xenografts in animals.

Mechanisms of inhibition of the thioredoxin growth factor system by antitumor 2-imidazolyl disulfides

The interactions of a series of 2-imidazolyl disulfide antitumor compounds with the thioredoxin reductase(TR)/thioredoxin (hTrx) redox system have been studied. Disulfides III-2 (n-butyl 2-mercaptoimidazolyl disulfide) and VI-2 (ethyl 2-mercaptoimidazolyl disulfide) were substrates for reduction by TR with Km values of 43 and 48 microM. Disulfides IV-2 (1-methylpropyl 2-mercaptoimidazolyl disulfide) and DLK-36 (benzyl 2-mercaptoimidazolyl disulfide) were competitive inhibitors of the reduction of hTrx by TR with Ki values of 31 microM. None of the disulfides were substrates for reduction by human glutathione reductase. The disulfides caused reversible thioalkylation of hTrx at the redox catalytic site as shown by the fact that there was no thioalkylation of a mutant hTrx where both the catalytic site Cys32 and Cys35 residues were replaced by Ser. In addition, the disulfides caused a slower irreversible inactivation of hTrx as a substrate for reduction by TR, with half-lives for III-2 of 30 min, for IV-2 of 4 hr, and for IX-2 (t-butyl 2-mercaptoimidazolyl disulfide) of 24 hr. This irreversible inactivation of hTrx occurred at concentrations of the disulfides an order of magnitude below those that inhibited TR, and involved the Cys73 of hTrx, which is outside the conserved redox catalytic site, as shown by the resistance to inactivation of a mutant hTrx where Cys73 was replaced by Ser. Electrophoretic and mass spectral analyses of the products of the reaction between the disulfides and hTrx show that modification of 1-3 Cys residues of the protein occurred in a concentration-dependent fashion. The disulfides inhibited the hTrx-dependent proliferation of MCF-7 breast cancer cells with IC50 values for III-2 and IV-2 of 0.2 and 1.2 microM, respectively. The results show that although the catalytic sites of TR and hTrx are reversibly inhibited by the 2-imidazolyl disulfides, it is the irreversible thioalkylation of Cys73 of hTrx by the disulfides that most probably accounts for the inhibition of thioredoxin-dependent cell growth by the disulfides.

Selenium and the thioredoxin redox system: effects on cell growth and death

Thioredoxin is a redox protein found overexpressed in some human tumors. Thioredoxin is secreted by tumor cells and enhances the sensitivity of the cancer cells to other growth factors. Redox activity is essential for stimulation of cell growth by thioredoxin. Cells transfected with thioredoxin cDNA show increased tumor growth and decreased apoptosis in vivo and decreased sensitivity to apoptosis induced by a variety of agents both in vitro and in vivo. Cells transfected with a redox-inactive mutant thioredoxin show inhibited tumor growth in vivo. Dietary selenium has been shown to prevent some forms of human cancer. Selenocysteine is an essential component of thioredoxin reductase, the flavoenzyme that is responsible for the reduction of thioredoxin. Selenium added to the culture medium increases thioredoxin reductase activity due to an increase in thioredoxin reductase protein but mostly due to an increase in the specific activity of the enzyme. Some diaryl chalcogenide (selenium and tellurium) compounds have been studied as inhibitors of thioredoxin reductase. The most active were diaryl tellurium compounds, which were noncompetitive inhibitors of thioredoxin reductase with Ki values of 2-10 microM. Several of the compounds inhibited cancer cell colony formation in vitro with IC50s as low as 2 microM.

Diaryl chalcogenides as selective inhibitors of thioredoxin reductase and potential antitumor agents

Thioredoxin reductase is a selenocysteine containing flavoenzyme that catalyzes the NADPH dependent reduction of the redox protein thioredoxin. Thioredoxin is over-expressed by a number of human tumors. Experimental studies have shown that thioredoxin is responsible for the growth and transformed phenotype of some human cancer cells. Thus, thioredoxin reductase presents an attractive target for anticancer drug development to regulate the activity of the thioredoxin system. We have examined a series of 12 organoselenium compounds and 16 organotellurium compounds, mostly of the diaryl chalcogenide type, as inhibitors of human thioredoxin reductase and have investigated the cytotoxicity and antitumor activity of some of the compounds. The organoselenium compound Ebselen was found to be a competitive inhibitor of human thioredoxin reductase (Ki 2.8 microM), while a number of organotellurium compounds were found to be noncompetitive inhibitors (Kis 2.3 to 35.2 microM). Human glutathione reductase was not appreciably inhibited by any of the compounds, except for one dinitro organotellurium compound that caused inhibition with an IC50 of 0.5 microM and an over 20-fold selectivity compared to thioredoxin reductase. The compounds inhibited the growth of human cancer cells in culture with IC50s as low as 2 microM Some organotellurium compounds when administered daily by intraperitoneal injection to mice caused up to 50% inhibition of the growth of MCF-7 human breast cancer xenografts but the relative insolubility of the compounds was a limiting factor in their use.

Partial growth-hormone insensitivity: the role of growth-hormone receptor mutations in idiopathic short stature

Mutations in the GHR locus may play a role in the cause of idiopathic short stature (ISS) by impairing growth-hormone (GH) receptor (GHR) function. At one extreme, mutations that nullify the function of the GH receptor are linked to complete GH insensitivity syndrome, or Laron syndrome, and we hypothesized that less-disruptive mutations could contribute to partial GH insensitivity syndrome. Low levels of GH binding protein may indicate mutations in the extracellular domain of the receptor, and by focusing on 14 children with ISS who had low GH binding protein and insulin-like growth factor I levels, we found three heterozygotes and one compound heterozygote for mutations in the extracellular domain of the receptor. We have since extended our study to a broader spectrum of patients, adding 76 patients with ISS who were treated with GH in a phase II study of the safety and efficacy of recombinant human GH in ISS and also adding 10 patients who were ascertained as having ISS by pediatric endocrinologists in private practice. The GHR gene has thus been analyzed in 100 patients with ISS, eight of whom were found to carry mutations: four in our original study and four with normal or elevated levels of GH binding protein. The latter group consists of three carriers of heterozygous extracellular domain mutations and one carrier of a heterozygous intracellular domain mutation. Family data suggest that the carriers of these mutations have a range of phenotypes, supporting our hypothesis that the expression of these heterozygous mutations as partial GH insensitivity syndrome depends on the genetic makeup of the person.

Macrotestes associated with hyperprolactinemia

Prolactin secreting pituitary adenomas are a rare finding in prepubertal children /1/. As in adults, their incidence is higher in girls than in boys; however, the macroadenomas are predominant in boys /20-16/. Two prepubertal boys who presented with short stature and linear growth deceleration were diagnosed to have prolactin secreting pituitary macroadenoma associated with growth hormone (GH) deficiency. They were treated with bromocryptine and exogenous recombinant hGH. They achieved a normal adult stature, full sexual maturation and tumor regression on the therapy. In addition, both boys developed macrotestes. Further evaluation ruled out other etiologies for macrotestes. We presume that the elevated prolactin caused local testicular growth factors to induce testicular cell division and/or hypertrophy resulting in an increased testicular volume.