Evolución de la saturación regional cerebral de oxígeno en el perioperatorio de cirugía torácica y su relación con la saturación venosa central / Evolution of regional oxygen saturation in the peri-operative of thoracic surgery and its relationship with central venous saturation

Objetivo. Estudiar la relación existente entre los valores de SvcO2 y de SrcO2 en la resección pulmonar con ventilación unipulmonar (VUP) y los cambios de dichas variables y de la presión arterial media (PAM) y la saturación arterial de oxígeno (SpO2) durante el periodo perioperatorio. Material y métodos. Estudio prospectivo observacional en 25 pacientes en quienes se realizó una resección pulmonar con VUP. Los valores de PAM, SpO2, SvcO2 y SrcO2 se registraron en 6 momentos diferentes: 1)basal; 2)en ventilación bipulmonar antes de la VUP (VBP1); 3)durante la VUP; 4)en ventilación bipulmonar después de la VUP (VBP2); 5)en los primeros 30min del postoperatorio, y 6)a las 6h de postoperatorio. Resultados. La SrcO2 mostró un aumento significativo desde su valor basal al iniciar la ventilación (65,72±9,05% vs 70,44±7,24%; p<0,01). No hubo cambios significativos en sus valores en los diferentes momentos intraoperatorios. En el postoperatorio, al igual que en el caso de la SvcO2, se observó una disminución significativa (p<0,001) de su valor en comparación con el valor previo. Conclusiones. La SrcO2 experimenta un aumento significativo tras la inducción de la anestesia e inicio de la ventilación mecánica respecto al valor basal y un descenso significativo al final de la cirugía, tras la extubación en el postoperatorio inmediato. Al tratarse de una monitorización tisular, no invasiva y continua, advierte al clínico de cambios en la relación DO2/VO2 en momentos de mayor riesgo como la VUP, la extubación y el periodo postoperatorio inmediato (AU)

Objective. To study the relationship between the values of SvcO2 and SrcO2 in lung resection with one lung ventilation (OLV) and changes in these variables and mean arterial pressure (MAP) and arterial oxygen saturation (SpO2) during the perioperative period. Material and methods. Prospective, observational study of 25 patients in whom pulmonary resection was performed with OLV. The values of MAP, SpO2, SvO2, and SrcO2 were recorded at 6 different times: 1)baseline; 2)double-lung ventilation before the OLV (VBP1); 3)during OLV; 4)after double-lung ventilation (VBP2); 5)30minutes after surgery, and 6)6hours after surgery. Results. The SrcO2 showed a significant increase from baseline to starting ventilation (65.72±9.05% vs 70.44±7.24%; P<.01). There were no significant changes in their values at the different intraoperative times. Post-operatively, as in the case of the SvcO2, a significant decrease (P<.001) of its value compared with the previous value was observed. Conclusions. SrcO2 showed a significant increase after induction of anaesthesia and initiation of mechanical ventilation compared to baseline, and a significant decrease at the end of surgery after extubation in the immediate postoperative period. Being a tissue monitoring, non-invasive technique and with continuous values it can alert the clinician of changes in the ratio of oxygen consumption (VO2) to oxygen delivery (DO2) at times of greatest risk, such as OLV, extubation, and the early postoperative period (AU)

Evolution of regional oxygen saturation in the peri-operative of thoracic surgery and its relationship with central venous saturation. / Evolución de la saturación regional cerebral de oxígeno en el perioperatorio de cirugía torácica y su relación con la saturación venosa central.

OBJECTIVE: To study the relationship between the values of SvcO2 and SrcO2 in lung resection with one lung ventilation (OLV) and changes in these variables and mean arterial pressure (MAP) and arterial oxygen saturation (SpO2) during the perioperative period. MATERIAL AND METHODS: Prospective, observational study of 25 patients in whom pulmonary resection was performed with OLV. The values of MAP, SpO2, SvO2, and SrcO2 were recorded at 6 different times: 1)baseline; 2)double-lung ventilation before the OLV (VBP1); 3)during OLV; 4)after double-lung ventilation (VBP2); 5)30minutes after surgery, and 6)6hours after surgery. RESULTS: The SrcO2 showed a significant increase from baseline to starting ventilation (65.72±9.05% vs 70.44±7.24%; P<.01). There were no significant changes in their values at the different intraoperative times. Post-operatively, as in the case of the SvcO2, a significant decrease (P<.001) of its value compared with the previous value was observed. CONCLUSIONS: SrcO2 showed a significant increase after induction of anaesthesia and initiation of mechanical ventilation compared to baseline, and a significant decrease at the end of surgery after extubation in the immediate postoperative period. Being a tissue monitoring, non-invasive technique and with continuous values it can alert the clinician of changes in the ratio of oxygen consumption (VO2) to oxygen delivery (DO2) at times of greatest risk, such as OLV, extubation, and the early postoperative period.

Ácido fólico (y III) / Folid acid (and III)

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Acido fólico (II) / Folic Acid (II)

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Ácido fólico (I) / Folic acid

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Liver proteolytic activity in tannic acid-fed birds.

The influence of tannic acid in the rate of growth (BWG), feed intake, protein efficiency ratio, and liver proteolytic activities (cathepsin A and D) were measured in growing male chickens. These birds were fed ad libitum over a 15-d experiment on 20% protein standard diets containing heated soybean (control, C) as the main source of protein. Tannic acid (TA; 25 g/kg diet) was added to all diets, except the control. It has been found that in comparison to control-fed birds, TA-fed birds showed a significant reduction (P < 0.01) in BWG, protein efficiency ratio, and relative weight of liver, together with a significant increase (P < 0.01) in the activities of cathepsin A and D in liver. Addition of TA to the control diet had no significant effect on feed intake. The possible nature of these results is discussed.

Antifibrogenic effect in vivo of low doses of insulin-like growth factor-I in cirrhotic rats.

Insulin-like growth factor-I (IGF-I) is produced mainly in the liver and it induces beneficial effects on the nutritional status, the liver function and oxidative hepatic damage in cirrhotic rats. The aim of this work was to analyze the effect of IGF-I on mechanisms of fibrogenesis in cirrhotic rats. Liver cirrhosis was induced by CCl(4) inhalation and phenobarbital in Wistar rats. Ten days after stopping CCl(4) administration (day 0), rats received either IGF-I (2 microg/100 g bw/day) (CI+IGF) or saline (CI) subcutaneously during 14 days. Animals were sacrificed on day 15. As control groups were used: healthy rats (CO) and healthy rats treated with IGF-I (CO+IGF). Liver histopathology, hydroxyproline content, prolyl hydroxylase activity, collagen I and III mRNA expression and the evolution of transformed Ito cells into myofibroblasts were assessed. Among the two control groups (CO+IGF), no differences were found in hydroxyproline content and these levels were lower than those found in the two cirrhotic groups. Compared with untreated cirrhotic rats, the CI+IGF-I animals showed a significant reduction in hydroxyproline content, prolyl hydroxylase activity and collagen alpha 1(I) and alpha1(III) mRNA expression. A higher number of transformed Ito cells (alpha-actin +) was observed in untreated cirrhotic animals as compared to CO and CI+IGF groups. In summary, treatment with IGF-I reduced all of the studied parameters of fibrogenesis. In conclusion, low doses of IGF-I induce in vivo an antifibrogenic effect in cirrhotic rats.

Hormone-related, muscle-specific changes in protein metabolism and fiber type profile after faba bean intake.

Male growing Wistar rats were fed, over 15 days, isoenergetic (16.72 +/- 0.49 MJ) and isoproteic (11%) diets containing either lactalbumin or raw Vicia faba L. (Vf) as the sole source of protein. Compared with pair-fed controls (PF), soleus muscles of Vf-fed rats showed increased (P < 0.05) synthesis and breakdown rates. In addition, the soleus of Vf-fed rats displayed a decrease (P < 0.05) in type I and an increase (P < 0.01) in type IIc fibers compared with that of PF animals. On the contrary, extensor digitorum longus muscles of both Vf-fed and PF rats showed an increase (P < 0.01) in type I and a reduction (P < 0.05) in type IIb fibers together with a decrease (P < 0.05) in the cross-sectional area of the latter fibers. Vf-fed rats exhibited a significant decrease in serum insulin (P < 0.05) and thyrotropin (P < 0.01) levels, together with an increase in plasma glucagon (P < 0.05) and 3,5,3'-triiodothyronine (P < 0.01) concentrations, compared with the PF group. Both Vf-fed and PF rats experienced an increase in corticosterone concentrations (P < 0.01 vs. control; P < 0.05 vs. PF). The muscle-specific changes in both protein metabolism and fiber type composition may partly depend on the hormonal changes that were observed after Vf intake.

Osteopenia in rats with liver cirrhosis: beneficial effects of IGF-I treatment.

BACKGROUND/AIMS: Liver cirrhosis is associated with osteopenia and also with low levels of IGF-I. This hormone has been reported to stimulate bone formation in states of undernutrition and low bone turnover. Our aims were to evaluate whether osteopenia develops in male Wistar rats with CCl4-induced cirrhosis and whether IGF-I is effective in the restoration of bone mass in these animals. METHODS: Cirrhotic rats were distributed into two groups: group CI (n = 12) which received placebo and group CI + IGF (n = 12) which was treated with human recombinant IGF-I (2 microg/100 g bw/day, s.c., 21 days). Twelve normal animals which received placebo constituted the control group. On the 22nd day, the animals were sacrificed, and bone parameters were analyzed in femur and/or tibia. RESULTS: Posterior-anterior and latero-medial diameters were similar in all groups. Also, no significant differences were observed in bone contents of calcium, total proteins, collagen and hydroxyapatite in CI rats as compared with controls. However, CI rats showed significant reductions in bone weight (-13.5%, p < 0.001), total bone density (-9.28%, p < 0.001), and increased perimedullar bone resorption and urinary levels of deoxypyridinoline (a marker of bone resorption). In CI + IGF rats these parameters improved significantly as compared with CI animals. CONCLUSIONS: Osteopenia characterized by loss of bone mass and preserved bone composition is found in rats with CCl4-induced cirrhosis. This bone disorder is partially corrected by treatment with low doses of IGF-I. Since osteoporosis seems to be the predominant form of osteopenia in patients with cirrhosis, IGF-I should be considered as a possible therapy for this disorder.

Hormonal implications of the hypocholesterolemic effect of intake of field beans (Vicia faba L.) by young men with hypercholesterolemia.

This study examined the hypocholesterolemic effect and hormonal changes resulting from 30 d of supplementation with Vicia faba L. (field bean) flour of diets of young men (aged 18-21 y; n = 40) with borderline-high or high serum cholesterol values. All subjects (groups A-D) consumed the same basic diet. Additionally, volunteers in the control group (A) consumed 90 g control flour/d whereas those in the three bean groups received either 90 g cooked field bean flour (groups B and C) or 90 g raw field bean flour (group D) daily. Groups A and B included volunteers with borderline-high cholesterol values [5.2-6.2 mmol total cholesterol/L and 3.4-4.1 mmol low-density-lipoprotein (LDL) cholesterol/L]. Subjects in groups C and D had high serum cholesterol concentrations (total cholesterol > 6.2 mmol/L and LDL cholesterol > 4.1 mmol/L). After 30 d, serum glucose, insulin, triacylglycerol, total, LDL-cholesterol, and very-low-density-lipoprotein (VLDL)-cholesterol values were significantly lower than initial values in all subjects who consumed diets containing field bean flour (P < or = 0.0001, except for LDL-cholesterol concentrations in group C, for which P < or = 0.0007). Legume intake also resulted in a significant increase (P < or = 0.0001) in glucagon and high-density-lipoprotein cholesterol. Neither cortisol nor thyroid hormone values changed significantly. The results suggest that the hypocholesterolemic effect of field bean intake depends at least partly on a concomitant increase in glucagon and decrease in insulin values. The more marked reduction in triacylglycerol and VLDL-cholesterol concentrations in subjects who consumed raw field beans indicates a coparticipation of their thermolabile components.

Hepatoprotective effects of insulin-like growth factor I in rats with carbon tetrachloride-induced cirrhosis.

BACKGROUND & AIMS: Bioavailability of insulin-like growth factor (IGF-I) is reduced in liver cirrhosis. The aim of this study was to analyze the effect of IGF-I on liver histopathology and function in experimental cirrhosis. METHODS: Rats received CCl4 inhalations for 11 or 30 weeks (protocols 1 and 2, respectively) and were treated with 2 microg x 100 g body wt(-1) x day(-1) IGF-I (group CI + IGF) or saline (group CI) on weeks 13 and 14 (protocol 1) or on weeks 28-30 (protocol 2). Normal rats were studied in parallel. RESULTS: Serum albumin and total protein levels were reduced in CI but not in CI + IGF rats compared with normal rats. Clotting factors II, VII, and X were significantly greater in CI + IGF than in CI rats. Liver lipid peroxidation products were significantly increased in CI but not in CI + IGF rats, and liver fibrosis was less pronounced in CI + IGF than in CI animals. The activities of antioxidant enzymes and mitochondrial transmembrane potential were reduced compared with normal animals in CI but not in CI + IGF rats. CONCLUSIONS: IGF-I improves liver function and reduces oxidative liver damage and fibrosis in rats with compensated or advanced liver cirrhosis. Improved mitochondrial function could play a role in the hepatoprotective effect of this hormone.

Impaired intestinal sugar transport in cirrhotic rats: correction by low doses of insulin-like growth factor I.

BACKGROUND & AIMS: Malnutrition is a complication of liver cirrhosis accompanied by reduced insulin-like growth factor I (IGF-I) availability. The aim of this study was to analyze the effect of IGF-I on intestinal D-galactose absorption in cirrhotic rats. METHODS: IGF-I (2 micrograms.100 g body wt-1.day-1) or saline were given for 14 days to rats in whom cirrhosis was induced with CCl4. Galactose transport and sodium-glucose/galactose-ligand transporter 1 (SGLT-1) expression were assessed in jejunal rings and in brush border membrane vesicles (BBMVs). RESULTS: Compared with that in controls, galactose transport in everted jejunal rings was significantly reduced in cirrhotic rats but showed normal values after IGF-I treatment. The kinetic study of D-galactose uptake by BBMVs showed decreased maximal velocity (Vmax) and diminished transporter affinity in cirrhotic rats. These kinetic parameters reverted to normal after IGF-I treatment. Microvilli were significantly elongated in cirrhotic rats but of normal size in the IGF-I-treated group. The expression of SGLT-1 on BBMVs (Western blot) and on the luminal membrane of enterocytes (immunohistochemistry) was not reduced in cirrhotic animals compared with controls or IGF-treated cirrhotic rats. CONCLUSIONS: Intestinal sugar transport is disturbed in experimental cirrhosis, and this alteration is corrected by IGF-I.

Low doses of insulin-like growth factor-I improve nitrogen retention and food efficiency in rats with early cirrhosis.

BACKGROUND/AIMS: In order to ascertain whether malnutrition is an early-onset feature of liver cirrhosis and whether the anabolic hormone insulin-like growth factor I (IGF-I) could be useful in the treatment of this complication, we analyzed the nutritional alterations present in rats with early-stage liver cirrhosis and the effects of IGF-I on nutritional parameters in these animals. METHODS: After a 24 h fast, a 15N-enriched diet was administered for 5 days to normal control rats and to cirrhotic rats receiving subcutaneous injections of vehicle (Group 1) or IGF-I, 2 micrograms.100 g bw-1.day-1, (Group 2) during the 5 experimental days. 15N, a stable N isotope, was measured in biological samples by mass spectrometry. RESULTS: Compared with control rats, Group 1 animals showed significant reductions in N intake and food efficiency (p < 0.05, both). In addition, the weight of the gastrocnemius muscle, its total N content and the dietary N content of this muscle were significantly lower in Group 1 than in control animals (p < 0.05, all). In rats from Group 2, mean values of N intake, food efficiency, gastrocnemius N content and the amount of dietary N incorporated into this muscle were similar to those in control rats, and (with the exception of gastrocnemius N total content) significantly higher than those in non-treated cirrhotic rats (p < 0.05, all). CONCLUSIONS: A variety of nutritional disturbances were detected in rats from the early stages of liver cirrhosis. Low doses of IGF-I were found to reverse most of these changes. These results stimulate further studies to determine whether IGF-I might be useful in the correction of the malnutrition present in patients with liver cirrhosis.

Effect of aging on the rate of muscle protein turnover in rat.

The urinary excretion of Nt-methylhistidine (e-methylhistidine, 3-MH, an index related to myofibrillar protein breakdown), as well as the rate of L-[14C]-tyrosine incorporation into gastrocnemius muscle (ks, fractional rate of muscle protein synthesis, evaluated by the constant infusion method) have been measured to assess the effect of aging on the rate of skeletal muscle protein turnover. In addition, nucleic acids, muscle protein and serum corticosterone levels were determined. Weaning rats were fed a 10% lactalbumin diet and killed in groups of seven when they were 35, 60, 120 and 300 days old. Apart from the rate of growth, no major differences were found between 35- and 60-day old animals. However, as compared to the youngest rats, 120-day old rats showed a significant reduction in the relative weight of the four muscles excised. Plasma corticosterone levels, increased as the animals became older. Finally, in the 300-day old rats, the reduced rate of growth was accompanied by a significant reduction in the relative organ weight (with the exception of soleus), 3-MH and Ks. It is concluded that aging caused a reduction in the rates of both protein breakdown and synthesis. The reduced muscle breakdown may not be due to a relative reduced muscle mass in elder rats since urinary 3-MH remained low even when expressed per creatinine output.

A potential experimental model for the study of osteopenia in CCl4 liver cirrhotic rats.

In order to search for an experimental model to further investigate the osteopenia associated to liver cirrhosis (LC), this study has been focused on investigating the occurrence of bone disorders in male rats to which LC histologically confirmed was induced through the validated procedure of CCl4 inhalation. Length, anteroposterior and lateromedial diameters, densitometry, mechanical stress resistance, hydroxyproline (OHprol) and calcium and phosphate contents were measured in femurs from control (n = 10) and liver cirrhosis rats (n = 10). It has been found that femurs from liver cirrhosis rats showed a significant reduction (p < 0.01) in bone weight (0.254 +/- 0.003 vs 0.230 +/- 0.004 g/100 g b.w.), anteroposterior (4.08 +/- 0.06 vs 3.69 +/- 0.05 mm) and lateromedial (5.33 +/- 0.05 vs 5.08 +/- 0.04 mm, p < 0.05) diameters, resistance to mechanical stress (405.8 +/- 9.5 vs 332.5 +/- 9.1 N) and total densitometry (0.416 +/- 0.005 vs 0.381 +/- 0.004 g/cm2). However, no significant differences were observed in bone length, calcium, OHprol and phosphate (all expressed as mg/100 mg fresh bone tissue) contents. Therefore, the proteins matrix to mineral contents ratio was not altered. These results indicate that in this model of experimental liver cirrhosis there is osteopenia characterized by bone frailty and reduced thickness, and it could offer an experimental model to study bone changes associated to liver cirrhosis.

A modified method for the indirect quantitative analysis of phytate in foodstuffs.

A simple, precise, and reproducible method to quantitatively assess total phytate content in foodstuffs has been developed. After HCl extraction, samples were run through an anion-exchange column and total phytate content of the eluates was spectrophotometrically measured with the modified Wade reagent. The main changes introduced in our procedure refer to pH adjustment in the extraction, dilution, and quantitation steps (pH 0.60, 6.00, and 3.00, respectively). Furthermore, the minimal extraction time for legumes (2 h) was determined. In addition, the effect of protein content on phytate determination was tested. Phytate content directly measured in crude extracts omitting anion-exchange chromatographic purification was significantly lower (P < 0.01) than values obtained using column separation, thus demonstrating that reliable phytate assessment in foodstuffs demands the utilization of anion-exchange chromatography.