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Biomedical subjects

R Company

Publications and source records attributed to R Company.

At least 19 recordsLinked to original sources
PubMed2005

Antioxidant systems and lipid peroxidation in Bathymodiolus azoricus from Mid-Atlantic Ridge hydrothermal vent fields.

Enzymatic defenses involved in protection from oxygen radical damage were determined in gills and mantle of Bathymodiolus azoricus collected from three contrasting Mid-Atlantic Ridge (MAR) hydrothermal vent fields (Menez-Gwen, Lucky Strike and Rainbow). The activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidases (GPx) (total and Se-dependent), and levels of total oxyradical scavenging capacity (TOSC), metallothioneins (MT) and lipid peroxidation (LPO) were determined in B. azoricus tissues and the impact of metal concentrations on these antioxidant systems and lipid peroxidation assessed. SOD, CAT, TOSC, MTs and LPO levels were higher in B. azoricus gills while glutathione peroxidases (total and Se-dependent) were higher in the mantle, and with the exception of CAT, were of the same order of magnitude as in other molluscs. TOSC levels from Menez-Gwen indicate that the vent environment at this site is less stressful and the formation of ROS in mussels is effectively counteracted by the antioxidant defense system. TOSC depletion indicates an elevated ROS production in molluscs at the other two vent sites. Cytosolic SOD, GPx and LPO were more relevant at Lucky Strike (Bairro Alto) where levels of essential (Cu and Zn) and toxic metals (Cd and Ag) were highest in the organisms. CAT activity and LPO were predominant at the Rainbow vent site, where an excess of Fe in mussel tissues and in vent fluids (the highest of all three vent sites) may have contributed to increased LPO. Therefore, three distinct pathways for antioxidant enzyme systems and LPO based on environmental metal speciation of MAR vent fields are proposed for Bathymodiolus gills. At Menez-Gwen, TOSC towards peroxyl and hydroxyl radicals and peroxynitrite are predominant, while at Lucky Strike cytosolic SOD activity and GPx are the main antioxidant mechanisms. Finally at Rainbow, catalase and lipid peroxidation are dominant, suggesting that resistance of mussels to metal toxicity at these vent fields decreases in the sequence Menez-Gwen > Lucky Strike and Rainbow.

Analysis of Variance↗
PubMed2004

[Bilateral compartment syndrome after surgical perfusion for chronic ischemia of the lower extremities].

A 61-year-old man diagnosed with advanced stage Leriche syndrome underwent revascularization surgery with placement of an aortobifemoral shunt and prosthesis under combined general and lumbar epidural anesthesia. After 6 hours he developed bilateral lower extremity compartment syndrome with acute anuric kidney failure caused by severe rhabdomyolysis. Thirty hours after surgery the patient suffered cardiac arrest due to hyperkalemia and was unresponsive to advanced cardiopulmonary resuscitation. The delay in diagnosis, in part owing to the epidural block provided for surgery, and loss of muscle mass led to the unfavorable outcome in this case.

Acute Kidney Injury↗
PubMed2001

Somatotropic regulation of fish growth and adiposity: growth hormone (GH) and somatolactin (SL) relationship.

Growth hormone (GH) and insulin-like growth factors (IGFs) play a major role in fish development and metabolism, and several studies have allowed discernment of a complex and tissue-specific collection of salmonid IGF-I transcripts (Ea-4, Ea-3, Ea-2, Ea-1), which are the result of the alternative splicing of the E-domain region. However, the pattern of IGF-I expression is different in non-salmonid fish, and only one or two transcripts (Ea-4, Ea-2) have been detected in hepatic and extrahepatic tissues of common carp, barramundi, black sea bream and gilthead sea bream. Despite this, when comparisons are made within Mediterranean fish species (European sea bass, common dentex and gilthead sea bream), plasma IGF-I levels are consistent with fish species differences in growth rates. Changes of growth rates, and plasma IGF-I and GH levels are also found in response to changes in diet composition and ration size, which may serve to assess the suitability of feeding regimes in aquaculture practice. Regulation of plasma somatolactin (SL) levels is also examined in gilthead sea bream, and the resulting plasma SL profile differs from that of GH. Thus, in contrast to GH, plasma SL levels augment with the increase of ration size and fish size (advancement of age). A transient increase in plasma SL levels is also found in short-term fasted fish, and this fish peptide may act as an anti-obesity hormone helping to expedite growth-reproductive processes following replenishment of fat stores, and/or mediate the adaptation to fasting until the lipolytic action of GH and/or other endocrine factors is fully accomplished. This agrees with the known increase of plasma SL levels during acute stress and exhaustive exercise. However, a causal link between SL and energy mobilisation (lipid metabolism) remains to be established, and further research is needed to determine the extent to which SL and GH act in a complementary manner to make available metabolic fuels and to regulate body fat mass and feeding behaviour.

Adipose Tissue↗
PubMed2001

[Multicenter study on the usefulness of the NasOral system for the denitrogenation and apneic oxygenation in anesthesia].

OBJECTIVES: To study the usefulness of the NasOral system for denitrogenation prior to anesthetic induction for improving pulmonary oxygen storage that maintains SpO2 within the normal range during induced apnea and facilitates apneic oxygenation. MATERIAL AND METHODS: To establish the study population of 125, five hospitals of the Valencian Community (Spain) enrolled patients scheduled for elective procedures under general anesthesia. The patients were preoxygenated using the NasOral system (denitrogenation). For two minutes, the patients inhaled oxygen through the nose (FiO2 1) at a flow rate of 8-10 l/min (never less than the patient's own minute volume) and exhaled orally through a unidirectional valve. We measured time of apnea with SpO2 > or = 96% to assess the usefulness of the device for denitrogenation. We also measured PetCO2 after endotracheal intubation and after maximum time of apnea (< or = 10 minutes) to assess use of the device for apneic oxygenation during laryngoscopy. RESULTS: We found no significant differences with regard to age, sex, ASA or Mallampati classification among patient groups enrolled at the participating hospitals. Cox's regression analysis was used to determine relative risk of SpO2 < 96%. At 10 minutes post-apnea, 88.8% of all patients maintained SpO2 > or = 96%. However, SpO2 > 96% was maintained by 94.1% in the Mallampati I group and by 84.1% in the Mallampati II group. SpO2 fell below the cut-off (< 96%) in 33.3% of obese patients and in 7.5% of non-obese patients. Analysis of the likelihood of SpO2 < 96% associated with the variables of obesity, sex, age, ASA and Mallampati classification was significant only for obesity, for which a risk of 1.95 was calculated relative to non-obesity (95% CI 1.14-3.35). The NasOral system allows performance of direct laryngoscopy for oral tracheal intubation, maintaining oxygen flow through the permeable airway to facilitate apneic oxygenation. CONCLUSIONS: The NasOral system facilitates denitrogenation before induction of anesthesia in all patients with permeable nasal fossae as well as apneic oxygenation during laryngoscopy.

Adolescent↗
PubMed2000

CDNA cloning and sequence of European sea bass (Dicentrarchus labrax) somatolactin.

Three cDNA clones encoding for European sea bass somatolactin (SL) were obtained by RT-PCR and 3' RACE of RNA of pituitary origin. Clone 1 was 582 bp in length, and included a part of the signal peptide and the 5' end of the mature protein. Clone 2 (1075 bp) included a fragment of the coding sequence and the 3' untranslated region, which was 888 bp in length and contained two putative polyadenylation signals (AATAAA) at 12-17, and 202-207 nucleotides upstream of the poly (A) tail. Clone 3 was 624 bp in length and its nucleotide sequence encoding for the entire mature protein confirmed the sequence already determined from the first two clones. The size of SL mRNA transcripts was estimated by Northern blot analysis and a single band of approximately 1.6 kb was observed with pituitary RNAs. No band was found with RNAs of brain and liver origin. Alignment of the deduced amino acid sequence revealed that European sea bass SL shared 90-84% identity with perciform, pleuronectiform and scorpaeniform fish SLs, and 77-57% with other SLs of more distant fish orders, with a strict conservation of Cys residues and the N-glycosylation site (Asn-Lys-Thr) at 121-123 amino acid positions. The reconstruction of the phylogenetic tree based on SL nucleotide sequences. and analyzed by maximum likelihood distances, showed the same clustering as the present hierarchy of fish. When comparisons were made among SL, prolactin and growth hormone of European sea bass, the overall amino identity was relatively low (22-23%). However, a high degree of amino acid homology was found at the C-terminus, which contains three of the four Cys residues strictly conserved in all the members of GH/PRL family.

3' Untranslated Regions↗
PubMed1995

[Surgical risk assessment using multivariate analysis].

INTRODUCTION: Over and above the risk of a disease itself, surgical treatment implies additional risk involving possible temporary or permanent deterioration in a patient's health. Most studies of anesthetic-surgical risk are based on mortality or serious morbidity (severe, permanent deterioration). They may therefore be of limited applicability in hospitals where such outcomes are rare due to the types of patients treated. In order to compare and classify patients as well as improve outcome in such health care settings other parameters must be evaluated. PATIENTS AND METHODS: Indicators presaging adverse situations related directly to surgery in our postoperative intensive care units involve blood transfusion and perioperative events. By applying multivariate (regression) analysis we can determine the factors that condition these unfavorable situations. RESULTS: In the setting we studied, the main determinants of unfavorable events after surgery are patient health as shown by ASA classification, duration of operation and type of surgery. CONCLUSIONS: 1) Peripheral surgery in patients in good health is very safe. 2) Easily obtained parameters can be used to obtain a fairly efficient prediction of risk. 3) Single-setting risk studies are easy to carry out and useful for providing information about a specific hospital center.

Adolescent↗
PubMedDate not supplied

Molecular cloning of superoxide dismutase (Cu/Zn-SOD) from aquatic molluscs.

The potential of the first line of the active oxygen-scavenging system, partial cDNA encoding Cu/Zn superoxide dismutase (SOD) was isolated in three aquatic mollusc species: Ruditapes decussatus (marine clam), Dreissena polymorpha (continental water mussel) and Bathymodiolus azoricus (hydrothermal vent mussel). These SOD cDNA fragments were amplified by PCR with degenerate oligonucleotide primers derived from the amino acid sequence conserved in the Cu/Zn-SOD from several other organisms. A partial cDNA of CuZn-SOD was obtained for R. decussates (510 bp), D. polymorpha (510 bp) and B. azoricus (195 bp). The deduced amino acid sequence showed high similarity among the three mollusc species (57-63%) and among other species (50-65%). The residues involved in coordinating copper (His-47, 49, 64, 121) and zinc (His-64, 72, 81 and Asp-84) were well conserved among the three Cu/Zn-SOD sequences.

Amino Acid Sequence↗
PubMedDate not supplied

Effect of cadmium, copper and mercury on antioxidant enzyme activities and lipid peroxidation in the gills of the hydrothermal vent mussel Bathymodiolus azoricus.

Metals are known to influence lipid peroxidation and oxidative status of marine organisms. Hydrothermal vent mussels Bathymodiolus azoricus live in deep-sea environments with anomalous conditions, including high metal concentrations. Although B. azoricus are aerobic organisms they possess abundant methano and thioautotrophic symbiotic bacteria in the gills. The enzymatic defences (superoxide dismutase (SOD), catalase (CAT), total glutathione peroxidase (Total GPx) and selenium-dependent glutathione peroxidase (Se-GPx)) and lipid peroxidation were determined in the gills of B. azoricus exposed to Cd (0.9 microM), Cu (0.4 microM) and Hg (0.1 microM) with different times of exposure. The experiments were performed in pressurized containers at 9+/-1 degrees C and 85 bars. Results show that vent mussels possess antioxidant enzymatic protection in the gills. Cd and Cu had an inhibitory effect in the enzymatic defence system, contrarily to Hg. These enzymatic systems are not completely understood in the B. azoricus, since reactive oxygen species might be produced through other processes than natural redox cycling, due to hydrogen sulphide and oxygen content present. Also the symbiotic bacteria may play an important contribution in the antioxidant protection of the gills.

Analysis of Variance↗
PubMedDate not supplied

[Application of high frequency jet ventilation during microsurgery of the larynx under suspending laryngoscopy].

OBJECTIVES: This study describes the results obtained with high frequency jet ventilation (HFJV) in 19 patients who underwent laryngeal microsurgery under suspending laryngoscopy. MATERIAL AND METHODS: After premedication and anesthetic induction with propofol (Diprivan R, ICI-Farma), we performed an endotracheal intubation (28F tube) under succinyl-choline facilitation. Conventional ventilation was started at a rate of 14-16 cpm with a minute volume of 8-10 l, and a FiO2 of 0.4 (air-oxygen). The endotracheal tube was replaced by an insufflation catheter of 2 mm internal diameter and HFJV was initiated at a rate of 100 cpm, inspiratory time equal to the 33% of the total cycle, generator pressure of 2.5-3.6 kg/cm2, and similar FiO2. We used an Ergojet CVT (Temel SA) respirator that allowed continuous monitoring of the injector released volume during each cycle (Vjet) as well as the air way pressure. Anesthesia was maintained with continuous propofol perfusion. RESULTS: During HFJV there were no significant hemodynamic alterations and surgeons considered that the condition of the surgical field was excellent. Air way pressure was maintained at low levels in all cases, although brief hypertensive episodes occurred during laryngeal manipulation. Oxygenation was satisfactory in all except one patient with chronic obstructive pulmonary disease. Conventional ventilation and HFJV did not induce significant differences in alveolar ventilation nor in PaCO2. However, during HFJV oxygenation and ventilatory levels suffered a high degree of interindividual variability. This phenomenon could be due to the existence of variable degrees of gas reflux during insufflation. CONCLUSIONS: We conclude that HFJV is a very useful technique for anesthesia in laryngeal microsurgery. However, an appropriate monitoring of ventilatory dynamics and a detailed knowledge of the influences of patient's characteristics on HFJV are required.

Adult↗
PubMedDate not supplied

[Performance analysis of a new anesthetic system: the Temel Supra--part I].

OBJECTIVES: To evaluate the performance of a new anesthetic system that purports to provide novel advantages in ventilating the anesthetized patient. MATERIAL AND METHODS: A performance analysis was carried out in our respirator function laboratory using lung simulators to assess the system, its degree of compliance with current regulations, and the degree of compliance with the manufacturer's claims. RESULTS: The system is 100% effective. The internal compliance of the respirator was 0.13 +/- 0.01 mL/cm H2O, inspiratory resistance was 1.9 +/- 0.1 cm H2O/L/s, expiratory resistance was 3.1 +/- 0.3 cm H2O/L/s, and internal volume was 130 mL. CONCLUSIONS: The Temel Supra device is versatile and meets the anesthetic requirements of patients undergoing any type of surgery. The possibility of using an open circuit, a low flow, a closed circuit, or a continuous flow without having to change to another system allows the anesthesiologist to make use of the advantages of each circuit without its drawbacks. The efficacy of the circuit is 100%. The low internal volume means that internal compliance is negligible and time constants are low, guaranteeing that the volume programmed is the same as the volume delivered and facilitating alveolar redistribution of gases. The monitoring and warning systems assure safe patient ventilation and accurate dosing of gases and anesthetic agents.

Anesthesiology↗