Preoperative fasting improves survival after 90% hepatectomy

OBJECTIVE: To assess whether alterations in preoperative fatty acid oxidation and gluconeogenesis induced by fasting will affect survival and liver regeneration following 90% hepatectomy in the rat. DESIGN: In a randomized, controlled trial, Wistar rats (N = 157) were separated into two groups. Rats in the first group fasted for 24 hours. Rats in the second group were allowed to eat ad libitum until the time of operation. These groups were further randomized to receive either 20% glucose or tap water ad libitum postoperatively. INTERVENTIONS: Ninety percent hepatectomy; 24-hour fast; 5% glucose feeding. MAIN OUTCOME MEASURES: Survival, DNA synthesis in the hepatic remnant along with glucokinase activity (GKA) and glycogen content, serum ketone bodies (KB), free fatty acid (FFA), glucose, and ad libitum glucose consumption (GC) were serially quantified. RESULTS: Fasting rats that were offered glucose (fasted/glucose) after hepatectomy demonstrated better survival at 48 hours than the rats that were fed before the procedure and given glucose following hepatectomy (fed/glucose), 95% vs 52% (P < .05). The fasted/glucose group also had a greater peak rate of DNA synthesis (550 +/- 110 vs 275 +/- 40 disintegrations per minute per 0.001 mg of DNA, P < .05). Survival was poor in both groups when only tap water was offered to the animals after hepatectomy (31% vs 12%). In the fasted/glucose group, GC 1 hour after hepatectomy was greater than that for fed rats (1.3 +/- 0.175 vs 0.73 +/- 0.176 g/h, P < .05), yet GKA was suppressed (3.4 +/- 0.42 vs 8.05 +/- 2.77 nmol/min per milligrams of protein, P < .05). Fasting before hepatectomy and consuming glucose after causes elevations in both FFA (1.26 +/- 0.19 vs 0.82 +/- 0.13 mol/mL., P < .05) and KB (18.96 +/- 2.82 vs 11.4 +/- 3.94 mmol/mL, P < .05). Normal glucose was maintained in the fasted/glucose group, but fell to 63 +/- 14 mg/dL at 8 hours after hepatectomy in the fed/glucose group. CONCLUSIONS: Fasting before hepatectomy shifts energy utilization to fat oxidation and gluconeogenesis, which appears to ameliorate liver failure after hepatectomy in this severe model of hepatic resection.     

Pre-incision infiltration with lidocaine reduces pain and opioid consumption after reduction mammoplasty

BACKGROUND: The main purpose of the reconstruction of the cranium is the protection of the brain. Besides we have to consider important functional and aesthetic necessities in order to achieve satisfactory results. METHODS: Thirty-six clinical cases, operated from November 1991 to June 1996, in which the reconstruction of the cranial vault is carried out by a polymethylmethacrylate acrylic resin are analysed. The causes and locations of the most common bone defects and the main indications for reconstruction are examined. While the repair of the osseous gaps caused by neoplasms is immediate, in the traumatic occurrences, in order to reduce the probability of infectious complications, an average time of 11 months elapsed from the first operation. The surgical technique, with slightest alterations, is the same in all the presented cases, preparing the acrylic resin straight on the operating table. The resin, moulded and adapted to the defect until its complete hardening, presents, thanks to its properties, manifold advantages (and few real disadvantages). RESULTS: The results, in terms of complications, are very satisfactory, with an infectious rate of 2.7%. Besides, in one third of the patients, a considerable clinical improvement after the repair has been observed. CONCLUSIONS: According to personal experience, it is possible to affirm that polymethylmethacrylate, with its remarkable plasticity and stability in time, can always guarantee a satisfactory functional and aesthetic result.     

Normoxic ventilation after cardiac arrest reduces oxidation of brain lipids and improves neurological outcome

BACKGROUND AND PURPOSE: Increasing evidence that oxidative stress contributes to delayed neuronal death after global cerebral ischemia has led to reconsideration of the prolonged use of 100% ventilatory O2 following resuscitation from cardiac arrest. This study determined the temporal course of oxidation of brain fatty acyl groups in a clinically relevant canine model of cardiac arrest and resuscitation and tested the hypothesis that postischemic ventilation with 21% inspired O2, rather than 100% O2, results in reduced levels of oxidized brain lipids and decreased neurological impairment. METHODS: Neurological deficit scoring and high performance liquid chromatography measurement of fatty acyl lipid oxidation were used in an established canine model using 10 minutes of cardiac arrest followed by resuscitation with different ventilatory oxygenation protocols and restoration of spontaneous circulation for 30 minutes to 24 hours. RESULTS: Significant increases in frontal cortex lipid oxidation occurred after 10 minutes of cardiac arrest alone with no reperfusion and after reperfusion for 30 minutes, 2 hours, and 24 hours (relative total 235-nm absorbing peak areas=7.1+/-0.7 SE, 17.3+/-2.7, 14.2+/-3.2, 16.1+/-1.0, and 14.0+/-0.8, respectively; n=4, P<0.05). The predominant oxidized lipids were identified by gas chromatography/mass spectrometry as 13- and 9-hydroxyoctadecadienoic acids (13- and 9-HODE). Animals ventilated on 21% to 30% O2 versus 100% O2 for the first hour after resuscitation exhibited significantly lower levels of total and specific oxidized lipids in the frontal cortex (1.7+/-0.1 versus 3.12+/-0.78 microg 13-HODE/g wet wt cortex., n=4 to 6, P<0.05) and lower neurological deficit scores (45.1+/-3.6 versus 58.3+/-3.8, n=9, P<0.05). CONCLUSIONS: With a clinically relevant canine model of 10 minutes of cardiac arrest, resuscitation with 21% versus 100% inspired O2 resulted in lower levels of oxidized brain lipids and improved neurological outcome measured after 24 hours of reperfusion. This study casts further doubt on the appropriateness of present guidelines that recommend the indiscriminate use of 100% ventilatory O2 for undefined periods during and after resuscitation from cardiac arrest.     

Counterconditioning reduces cue-induced craving and actual cue-elicited consumption.

Cue-induced craving is not easily reduced by an extinction or exposure procedure and may constitute an important route toward relapse in addictive behavior after treatment. In the present study, we investigated the effectiveness of counterconditioning as an alternative procedure to reduce cue-induced craving, in a nonclinical population. We found that a cue, initially paired with chocolate consumption, did not cease to elicit craving for chocolate after extinction (repeated presentation of the cue without chocolate consumption), but did so after counterconditioning (repeated pairing of the cue with consumption of a highly disliked liquid, Polysorbate 20). This effect persisted after 1 week. Counterconditioning moreover was more effective than extinction in disrupting reported expectancy to get to eat chocolate, and also appeared to be more effective in reducing actual cue-elicited chocolate consumption. These results suggest that counterconditioning may be more promising than cue exposure for the prevention of relapse in addictive behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mechanomyography and oxygen consumption during incremental cycle ergometry

Brucella abortus strain RB51 was recently approved as an official brucellosis calfhood vaccine for cattle by the Animal and Plant Health Inspection Service branch of the United States Department of Agriculture. Currently available serologic surveillance tests for B. abortus do not detect seroconversion following SRB51 vaccination. The purpose of this study was to evaluate a dot-blot assay using gamma-irradiated strain RB51 bacteria for its specificity and sensitivity to detect antibody responses of cattle vaccinated with strain RB51. Dot-blot titers of sera at a recommended dosage (10(10) colony-forming units) were similar to those of sera from cattle vaccinated with similar numbers of B. abortus strain 19 and greater (P < 0.05) than titers of nonvaccinated cattle. In the first 12 weeks after vaccination with 10(10) colony-forming units of strain RB51, the RB51 dot-blot assay had 100% specificity for titers of 80 or less and a 53% sensitivity for titers of 160 or greater. Sensitivity of the RB51 dot-blot assay peaked at 4 weeks after vaccination with 10(10) colony-forming units of strain RB51. Dot-blot responses of sera from cattle vaccinated with a reduced dosage of strain RB51 (10(9) colony-forming units) did not differ (P > 0.05) from titers of sera from nonvaccinated cattle. Following intraconjunctival challenge with B. abortus strain 2308, titers on the RB51 dot-blot assay did not differ (P > 0.05) between nonvaccinated cattle and cattle vaccinated at calfhood with strain 19 or strain RB51.     

Low-volume resuscitation with a hemoglobin-based oxygen carrier after hemorrhage improves gut microvascular oxygenation in swine

Using palladium-porphyrin quenching of phosphorescence, we investigated the influence of diaspirin cross-linked hemoglobin (DCLHb) on gut microvascular oxygen pressure (microPO2) in anesthetized pigs. Values of gut microPO2 were studied in correlation with regional intestinal as well as global metabolic and circulatory parameters. A controlled hemorrhagic shock (blood withdrawal of 40 mL/kg) was followed by resuscitation with either a combination of lactated Ringer's solution (75 mL/kg) and modified gelatin (15 mL/kg)(lactR/Gel) or 10% DCLHb (5 mL/kg). After resuscitation, gut microPO2 was similarly improved in the lactR/Gel group (from 25 +/- 10 mm Hg to 53 +/- 8 mm Hg) and the DCLHb group (from 23 +/- 9 mm Hg to 46 +/- 6 mm Hg), which was associated with increased gut oxygen delivery. However, the improvement after resuscitation with DCLHb was sustained for longer periods of time (75 vs 30 min). Mesenteric venous PO2 was increased after resuscitation with lactated Ringer's solution and modified gelatin but not with DCLHb, which was associated with an increased gut oxygen consumption in the latter group. We conclude that measurement of microPO2 by the palladium-porphyrin phosphorescence technique revealed DCLHb to be an effective carrier of oxygen to the microcirculation of the gut. Also, this effect can be achieved with a lower volume than is currently used in resuscitation procedures.     

rG-CSF reduces endotoxemia and improves survival during E. coli pneumonia

We investigated the effects of recombinant granulocyte colony-stimulating factor (rG-CSF) during canine bacterial pneumonia. Beagles with chronic tracheostomies received daily subcutaneous rG-CSF (5 micrograms/kg body wt) or placebo for 14 days, beginning 9 days before intrabronchial inoculation with E. coli. Animals received antibiotics and fluid support; a subset received humidified oxygen (fractional inspired O2 0.40). Compared with controls, rG-CSF increased circulating neutrophil counts (57.4 vs. 11.0 x 10(3)/mm3, day 1 after infection; P = 0.0001), decreased plasma endotoxin (7.5 vs. 1.1 EU/ml at 8 h; P < 0.01) and serum tumor necrosis factor-alpha (3,402 vs. 729 pg/ml at 2 h; P = 0.01) levels, and prolonged survival (relative risk of death = 0.45, 95% confidence interval 0.21-0.97; P = 0.038). Also, rG-CSF attenuated sepsis-associated myocardial dysfunction (P < 0.001). rG-CSF had no effect on pulmonary function or on blood and lung bacteria counts (all P = not significant). Other animals challenged with endotoxin (4 mg/kg i.v.) after similar treatment with rG-CSF had lower serum endotoxin levels (7.62 vs. 5.81 log EU/ml at 6 h; P < 0.01) and less cardiovascular dysfunction (P < 0.05 to < 0.002) but similar tumor necrosis factor-alpha levels (P = not significant) compared with controls. Thus prophylactic rG-CSF sufficient to increase circulating neutrophils during bacterial pneumonia may improve cardiovascular function and survival by mechanisms that in part enhance the clearance of bacterial toxins but do not improve lung function.     

Productivity and maximal oxygen consumption in sugar cane cutters

Vo2max and daily productivity (metric tons/day) have been measured in 46 sugar cane cutters 18 to 34 years of age. A multiple regression analysis demonstrated that productivity was simultaneously related to VO2max, height and body fat (r=0.685;P less than 0.001). The multiple regression equation was: productivity (tons/day)=0.81 VO2max-0.14 percent fat +0.03 height -1.96. The data indicate that productivity is affected indirectly by nutritional status through the influence of the latter on height, fat content and VO2max. The decrease in VO2max that occurs with age was similar to that reported in the literature. Evidence is presented that, as the worker ages, a higher percent VO2max has to be utilized to maintain productivity.     

Chronic administration of oxprenolol and metoprolol attenuate sympathetic cardiovascular responses only in non-adrenalectomized pithed rats

1. Oxprenolol and metoprolol (30 mg kg-1) were injected intraperitoneally (i.p.) for 1 day (acute treatment) and 6 weeks (chronic treatment) to Sprague-Dawley rats. 2. Increases of mean blood pressure and heart rate to noradrenaline (0.1-10 micrograms kg-1) and to electrical stimulation (0.5 msec, supramax V, 0.25-5 Hz) of the entire sympathetic outflow were measured in non-adrenalectomized (acute and chronic) and adrenalectomized (chronic) pithed rats. 3. Acute beta-adrenoceptor antagonist administration was without effect on mean blood pressure and heart rate increases to noradrenaline and electrical stimulation. 4. Chronic administration with oxprenolol significantly diminished the stimulation-induced increases of mean blood pressure and heart rate in non-adrenalectomized pithed rats. 5. Increases in heart rate, elicited by stimulation of the entire sympathetic outflow in non-adrenalectomized but not in adrenalectomized pithed rats, were decreased by metoprolol treatment. Both treatments were without effect on noradrenaline responses. 6. These results indicate that chronic beta-adrenoceptor antagonist treatment is associated with a reduction in the cardiovascular responses to sympathetic nerve-stimulation. However, this mechanism only operates when adrenomedullary adrenaline is present to facilitate the noradrenaline release through activation of presynaptic beta 2-adrenoceptors.     

Ambulatory sports in asthma improves physical fitness and reduces asthma-induced hospital stay

BACKGROUND: Prevention of posttransfusion non-A,non-B hepatitis in recipients of blood components improved considerably with the introduction of the second-generation of hepatitis C virus (HCV) antibody tests. In 1993, third-generation HCV antibody assays were introduced in Europe. STUDY DESIGN AND METHODS: The performance of three generations of anti-HCV enzyme-linked immunosorbent assay (ELISA) (ELISA-1, -2, -3) was compared in routine blood donor screening (99,394 donations were tested with ELISA-1, 167,999 donations with ELISA-2, and 262,090 donations with ELISA-3) and in serial samples from nine patients with documented acute posttransfusion HCV infection. RESULTS: Eight (0.01%) repeat donors, previously negative in ELISA-1, were found positive in ELISA-2 and were confirmed as positive in second-generation recombinant immunoblot assay and/or cDNA polymerase chain reaction. In the donor population, no difference in the sensitivity of ELISA-2 and -3 was observed. The specificity of the three generations of ELISAs was comparable (99.8, 99.7, and 99.7%). In seroconversion samples, ELISA-2 and -3 detected HCV antibodies at the same time in seven patients, but in two patients, ELISA-3 found HCV antibodies, respectively, 63 and 77 days earlier than ELISA-2 did. In the seroconversion samples, ELISA-2 and -3 were significantly more sensitive than second- and third-generation recombinant immunoblot assays. CONCLUSION: ELISA-3 did not detect more HCV-infected individuals in a donor population that previously tested negative in ELISA-2, but it did detect HCV antibodies earlier in some patients with acute HCV infection. ELISA-2 and -3 were significantly more sensitive than second- and third-generation recombinant immunoblot assays.     

Bone marrow oxygen consumption and erythropoiesis in chronically hypoxic rats

Bone marrow oxygen consumption (VO2) was determined weekly in 16 Holtzman rats exposed to continuous hypobaric hypoxia (CHH) during 30 days. The results were compared with those obtained in 10 sea level control animals (SL). The VO2 expressed as ng.at.O2/min, decreased progressively with time of exposure to hypoxia. VO2 (mean +/- SD) was 0.0936 +/- 0.135 in SL rats. In CHH animals, it was 0.1001 +/- 0.0292 after 8 days of hypoxia, 0.1030 +/- 0.0206 after 16 days, 0.0594 +/- 0.0148 (p = 0.002) after 24 days and 0.0136 +/- 0.404 (p = 0.000) after 30 days. Protein concentration in bone marrow was progressively higher in hypoxics when compared to control, with significant differences since the first week of exposure. Blood hemoglobin increased in parallel to protein concentration in the bone marrow. These findings suggest an increase in the cells of the erythroid series whose oxygen consumption is less than cells in the early stages of differentiation. The increased protein concentration is in agreement with the fact that globin mRNA appears in cells with a progressively increasing anaerobic metabolism at relatively late stages of erythropoiesis.     

Preoperative preparation for cardiac surgery facilitates recovery, reduces psychological distress, and reduces the incidence of acute postoperative hypertension.

This study evaluated whether preoperative preparations for cardiac surgery (a) reduced psychological distress and facilitated physical recovery, (b) reduced preoperative anxiety by making patients feel well-informed or by increasing their sense of control over recovery, and (c) reduced the incidence of sympathetically mediated, acute postoperative hypertension. Information-only and information-plus-coping preparations were compared with a contact-control preparation. Preoperatively (1 day after preparation), both experimental groups were significantly less anxious and fearful than the control group. The experimental groups did not differ from each other. Both experimental preparations increased patients' belief in control over recovery. Consistent with Lazarus's theory of stress, belief in control over recovery best predicted preoperative anxiety. Regression analyses indicated that information reduced anxiety by increasing feelings of control. Postoperatively, both experimental groups (a) reported less emotional distress, (b) were judged by nurses as making better physical and psychological recoveries, and (c) had a 32.5% lower incidence of postoperative hypertension. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Improving blast-furnace operation by optimizing the natural-gas and oxygen consumption

The goal is to improve the operation of a group of blast furnaces by redistribution of the available energy resources between them. Analysis of production data yields the energy characteristics of the blast furnaces. Consumption figures are used to develop recommendations regarding the rational distribution of energy resources between the furnaces so as to reduce the overall coke consumption by 2.0?C2.5 kg/t of hot metal. The optimal theoretical combustion temperature in all the furnaces may be derived by correlation calculations and used to determine the optimal ratio of oxygen and natural-gas consumption. In furnace operation at near-optimal temperature, the coke consumption is reduced by 0.40?C0.90 kg/t of hot metal, while the productivity rises by 1.2?C3.1%.     

Renal function and oxygen consumption during bacteraemia and endotoxaemia in rats

BACKGROUND: The hypothesis that renal failure during septic shock may occur as a result of hypoxia-related cell dysfunction was investigated in two rat models of distributive shock. METHODS: Pentobarbitone-anaesthetized rats received either a bolus (1 ml) of living Escherichia coli bacteria (hospital-acquired strain, 1 x 10(9) CFU/ml; BA-group, n = 7), or a 1-h infusion of endotoxin (E. coli O127.B8: 8 mg/kg; ET-group, n = 7), or saline to serve as time matched controls (C-group, n = 7). RESULTS: Urine flow in the BA- and ET-group reached a nadir at 1 h, but thereafter increased and reached values higher than control at 3 h. At this time point, renal oxygen delivery had decreased, in the BA-group mainly due to a fall in arterial oxygen content and in the ET-group to a fall in renal plasma flow (clearance of 131I-hippurate). However, renal oxygen extraction had significantly increased, by 31% in the BA and by 59% in the ET group, while renal oxygen consumption remained the same. Net tubular sodium reabsorption had decreased by 55% in the BA and by 25% in the ET group, due to a fall in glomerular filtration rate (clearance of creatinine). Hence, an excess oxygen consumption was found which was caused neither by an increased renal glucose release nor by the presence of an increased number of leukocytes stuck in the glomeruli. Renal tubular cells showed normal morphology. An indication that proximal tubular function in the BA and ET group remained largely intact were normal ATP levels, absence of urinary glucose, and a normal fractional excretion of sodium. However, since urine flow had increased in shocked rats at 3 h, water appeared selectively lost. CONCLUSIONS: Our data indicate that in rat models of septic shock renal failure is not caused by cortical hypoxia or a shortage of cellular energy supply.     

Perfusion-induced changes in cardiac contractility and oxygen consumption are not endothelium-dependent

OBJECTIVE: Are substances released from rat coronary endothelial cells responsible for the increase in contractility and oxygen consumption (Gregg phenomenon) seen with an increase in cardiac perfusion? METHODS: In an isovolumically contracting, Langendorff, crystalloid perfused rat heart (n = 6) at 27 degrees C, coronary flow was changed (from 4.4 to 15.4 ml.min-1.gww(-1)) before and after the endothelium was made dysfunctional by Triton X-100. Vascular endothelium and smooth muscle function were tested with bradykinin (BK, 1 microM, an endothelium-dependent dilator) and papaverine (PAP, 1 microM, an endothelium-independent dilator) in a preconstricted vascular bed (vasopressin, VP, 3 nM). RESULTS: Before Triton X-100, coronary resistance (at constant flow) decreased significantly in response to BK and to PAP. After Triton X-100 treatment the dilatory response to BK was abolished while the PAP response was still present, suggesting endothelial dysfunction with intact smooth muscle function. Due to Triton X-100 treatment, coronary resistance increased significantly. Therefore coronary flow changes were also applied during a similar increase in coronary resistance induced by VP infusion (3 nM) before Triton X-100 treatment. During control, developed left ventricular pressure (dev Plv) increased with 68 +/- 21% and oxygen consumption (VO2) increased with 122 +/- 25% in response to the maximal increase in coronary flow. During increased coronary resistance with and without functional endothelium, dev Plv increased by 57 +/- 16 and 64 +/- 22%, respectively, and VO2 increased by 126 +/- 21 and 103 +/- 20%, respectively, in response to the maximal increase in flow. These changes were not significantly different from control. CONCLUSION: The results suggest that the arterial endothelium is not involved in the Gregg phenomenon.