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Biomedical subjects

F Carli

Publications and source records attributed to F Carli.

At least 37 records · Page 2Linked to original sources

Integrated analysis of protein and glucose metabolism during surgery: effects of anesthesia.

The aim of this study was to assess dynamic changes in protein and glucose metabolism during surgery. Twelve patients undergoing colorectal surgery received either intravenous propofol anesthesia (n = 6) or inhalational anesthesia with desflurane (n = 6). Pre- and intraoperative protein and glucose kinetics were analyzed by an isotope dilution technique using L-[1-(13)C]leucine and [6,6-(2)H(2)]glucose. Plasma concentrations of glucose, lactate, free fatty acids, insulin, glucagon, and cortisol were measured before and after 2 h of surgery. The rates of appearance of leucine and glucose, leucine oxidation, protein synthesis, and glucose clearance decreased during surgery, independent of the type of anesthesia (P < 0.05). A correlation between the rate of appearance of leucine and glucose was observed (r = 0.755, P < 0.001). Intraoperative plasma cortisol and glucose concentrations increased (P < 0.05), whereas plasma concentrations of lactate, free fatty acids, insulin, and glucagon did not change. Surgery causes a depression of whole body protein and glucose metabolism, independent of the anesthetic technique. There is a correlation between perioperative glucose production and protein breakdown.

Adult↗

Perioperative medicine. Are the anesthesiologists ready?

Perioperative medicine starts with preoperative assessment and preparation of patients undergoing various procedures. It includes intraoperative care and continues postproceudral management, from recovery room to intensive care and step-down facilities. Acute pain management must be optimized in order to enhance rehabilitation and restoration of functions. Perioperative medicine also includes management of acute and chronic pain. Potential areas of anesthesia involvement, still unclear, include preoperative and postoperative ward management and complete preparation such as cardiology or pulmonary testing. Further steps to take in the direction of perioperative medicine are the development of a different model of resident training, and the improvement of information technology and medical record.

Anesthesiology↗

Analysis of repair of abasic sites in early onset breast cancer patients.

Defective DNA repair has been suggested as a possible predisposing factor for breast cancer. We have investigated the repair of the frequent endogenous lesions abasic sites in sporadic early onset breast cancer patients and matched control individuals. No significant difference was observed between the abasic site repair capacities of peripheral blood lymphocytes from cases and controls. Repair of abasic sites was also studied in tumor and surrounding normal tissues of the patients. The 2 tissues showed marked differences in histology and protein composition with a fibro-collagenous component varying from sample to sample but invariably higher in normal tissues as compared with the adjacent tumor. These differences involved the need to calculate the repair activities of tissues on the basis of cellular DNA content for comparison purposes. After doing so, tumor and normal tissues exhibited similar abasic site repair capacities, whereas lymphocytes showed a repair capacity significantly lower than tissues. We conclude that early onset sporadic breast cancer patients show no evident defect in repair of abasic sites at the level of both lymphocytes and tumor.

Adult↗

Pattern of lymphatic drainage to the sentinel lymph node in breast cancer patients.

BACKGROUND AND OBJECTIVE: We performed a pilot study on 30 consecutive patients undergoing sentinel node (sN) biopsy by radioguided surgery and vital blue dye mapping to determine whether there is a single sN for each breast independent of tumor site or an sN specifically related to the site of the breast neoplasm. METHODS: There were 6 groups of 5 patients; each patient had a subdermal injection of radiotracer on the tumor site plus a second injection of radiotracer that was changed in every subset of patients to test whether modifying the site or the route of injection could have impaired the proper detection of the sN. RESULTS: "False" sN were detected only in patients who had a second injection of radiotracer away from the tumor site; this occurred in 2 of 5 patients (40%) in group I, in 3 of 5 patients (60%) in group II, in all patients in group III, and in 3 of 5 patients (60%) in group IV. The different route of injection (peritumoral or subdermal) always on the tumor site that was tested in groups V and VI did not impair the proper detection of the sN. CONCLUSIONS: Our findings support the hypothesis of a precise topographic correspondence between the primary tumor and its specific sN more than the existence of a first sN in the axillary basin, which indiscriminately drains all quadrants of the breast, like "a neck of a bottle." This should be considered for the proper selection of the injection site of either vital blue dye or radiopharmaceuticals.

Adult↗

Mapping sentinel lymph node in breast cancer by combined lymphoscintigraphy, blue-dye, and intraoperative gamma-probe.

The purpose of the present work was two-fold: 1) to evaluate the predictive value of the sentinel lymph node (sLN) versus the axillary-node status in patients with T1-T2 breast cancer, and 2) to form an experimental basis for a randomized trial in which one group of patients with non-metastatic sLN will not have axillary dissection. Of a group of 284 patients considered for this analysis, 264 had a T1 cancer (16 T1a, 37 T1b and 211 T1c), while 20 had a T2 cancer; 243 patients were in clinical stage N0 and 41 were N1. All patients underwent lymphoscintigraphy 18 hr before surgery: 10 MBq in 0.15 mL of 99mTc-human albumin nanocolloids (particle size between 50-80 nm) was injected subdermally at the cutaneous projection of the tumor. Static gamma-camera images were acquired every 10-15 minutes until scintigraphic identification of the sLN. At surgery, 1-2 mL of Patent-Blue Violet was injected subdermally, and the sLN was searched by gamma-probe and by the dye method. The surgically isolated sLN was processed for intraoperative Hematoxylin & Eosin (H&E) histology, then for delayed histological and immunohistochemical examinations. The sLN was successfully identified by the combined radioisotopic procedure and Patent-Blue dye technique in 278/284 cases (97.9%). The Patent-Blue dye technique alone identified fewer sLNs than the radioisotopic procedure alone (56.3% versus 97.2%). Analysis of the predictive value of the sLN as to the status of axillary lymph nodes was limited to 197 patients undergoing standard axillary dissection irrespective of the sLN status. Overall, 63/191 (33%) identified sLNs were metastatic, the sLN alone being involved in 37/63 (58.7%) patients; a positive axilla status with negative sLN was found in 10/73 patients with metastatic involvement (13.7% false-negative rate). In conclusion, subdermal lymphoscintigraphy was confirmed to be an effective technique for sLN mapping; the addition of Patent-Blue dye minimally improved intra-surgical identification of the sLN. There was a high, but not absolute, correlation between a negative sLN and a negative axilla.

Adult↗

Randomized controlled comparison of epidural bupivacaine versus pethidine for analgesia in labour.

We compared the incidence of Caesarean delivery in nulliparous women randomized to receive epidural analgesia with those randomized to intramuscular (i.m.) pethidine. On admission to the delivery suite in established labour, 802 nulliparae had already agreed to be randomized with respect to their first analgesia. One hundred and eighty-eight women required either no analgesia or 50% nitrous oxide in oxygen (Entonox) only. Of the remaining 614 women, 310 were randomly allocated to receive i.m. pethidine up to 300 mg and 304 to receive epidural bupivacaine. Labour management was standardized according to the criteria for active management of labour. The intention-to-treat analysis showed similar Caesarean section rates in those randomized to epidural (12%) or pethidine analgesia (13%). The difference in Caesarean rate was -1.1% with 95% confidence intervals from -6.3% to +4.1%. The normal vaginal delivery rates were similar (epidural, 59%; pethidine, 61%).

Adolescent↗

Propofol/sufentanil anesthesia suppresses the metabolic and endocrine response during, not after, lower abdominal surgery.

UNLABELLED: We investigated the influence of propofol/sufentanil anesthesia on metabolic and endocrine responses during, and immediately after, lower abdominal surgery. Twenty otherwise healthy patients undergoing abdominal hysterectomy for benign myoma received either continuous infusions of propofol supplemented with sufentanil (0.01 microg. kg(-1). min(-1), n = 10) or enflurane anesthesia (enflurane, n = 10). Plasma concentrations of glucose, lactate, free fatty acids, triglycerides, insulin, glucagon, cortisol, epinephrine, and norepinephrine were measured before, during, and 2 h after surgery. Pre- and postoperative endogenous glucose production (R(a) glucose) was analyzed by an isotope dilution technique by using [6,6-(2)H(2)] glucose. Propofol/sufentanil anesthesia prevented the increase in plasma cortisol and catecholamine concentrations and attenuated the hyperglycemic response during surgery without showing any difference after the operation. Mediated through a higher glucagon/insulin quotient (propofol/sufentanil 15 +/- 7 versus enflurane 8 +/- 4 pg/microU, P < 0.05), the R(a) glucose postoperatively increased more in the propofol/sufentanil than in the enflurane group (propofol/sufentanil 15.6 +/- 2.0 versus enflurane 13.4 +/- 2.2 micromol. kg(-1). min(-1), P < 0.05). IMPLICATIONS: The concept of stress-free anesthesia using propofol combined with sufentanil is valid only during surgery. The metabolic endocrine stress response 2 h after the operation is more pronounced than after inhaled anesthesia.

Anesthesia, Intravenous↗

Effect of epidural blockade on protein, glucose, and lipid metabolism in the fasted state and during dextrose infusion in volunteers.

BACKGROUND: To interpret correctly the results from studies performed during surgery and anesthesia it is necessary to dissect the separate effect of the anesthetic technique itself. The purpose of this study was to investigate the metabolic effects of epidural blockade (T7-S1) with bupivacaine 0.25% after 12 h fasting and during administration of 4 mg x kg(-1) x min(-1) dextrose in six healthy volunteers. METHODS: Each volunteer was assigned to randomly undergo a 6-h multiple stable isotope infusion study (3 h fasted, 3 h dextrose infusion) with or without epidural blockade. L-[1-13C]leucine, [6,6-2H2]glucose, and [1,1,2,3,3-2H5]glycerol were infused to measure protein synthesis, breakdown, and amino acid oxidation; glucose production and clearance; and lipolysis. Plasma concentrations of glucose, lactate, glycerol, free fatty acids, insulin, and glucagon were determined. RESULTS: Epidural blockade with bupivacaine had no influence on protein oxidation, breakdown and synthesis, glucose production, glucose clearance and lipolysis in the fasted state. Plasma concentrations of metabolic substrates and hormones also were not affected. Dextrose infusion significantly increased glucose clearance and plasma concentrations of glucose and insulin, while endogenous glucose production and lipolysis decreased to a similar degree in both groups. Protein synthesis, breakdown, and oxidation did not change during dextrose infusion. CONCLUSIONS: Epidural blockade with bupivacaine in the absence of surgery has no effect on fasting protein, glucose, and lipid metabolism. Epidural blockade does not modify the inhibitory influence of dextrose administration on endogenous glucose production and lipolysis.

Adult↗

Effect of ambient temperature on human pain and temperature perception.

BACKGROUND: Animal studies show reduced nociceptive responses to noxious heat stimuli and increases in endogenous beta-endorphin levels in cold environments, suggesting that human pain perception may be dependent on ambient temperature. However, studies of changes in local skin temperature on human pain perception have yielded variable results. This study examines the effect of both warm and cool ambient temperature on the perception of noxious and innocuous mechanical and thermal stimuli. METHODS: Ten subjects (7 men and 3 women, aged 20-23 yr) used visual analog scales to rate the stimulus intensity, pain intensity, and unpleasantness of thermal (0-50 degrees C) and mechanical (1.2-28.9 g) stimuli applied on the volar forearm with a 1-cm2 contact thermode and von Frey filaments, respectively. Mean skin temperatures were measured throughout the experiment by infrared pyrometer. Each subject was tested in ambient temperatures of 15 degrees C (cool), 25 degrees C (neutral), and 35 degrees C (warm) on separate days, after a 30-min acclimation to the environment. Studies began in the morning after an 8-h fast. RESULTS: Mean skin temperature was altered by ambient temperature (cool room: 30.1 degrees C; neutral room: 33.4 degrees C; warm room: 34.5 degrees C; P < 0.0001). Ambient temperature affected both heat (44-50 degrees C) and cold (25-0 degrees C) perception (P < 0.01). Stimulus intensity ratings tended to be lower in the cool than in the neutral environment (P < 0.07) but were not different between the neutral and warm environments. Unpleasantness ratings revealed that cold stimuli were more unpleasant than hot stimuli in the cool room and that noxious heat stimuli were more unpleasant in a warm environment. Environmental temperature did not alter ratings of warm (37 and 40 degrees C) or mechanical stimuli. CONCLUSIONS: These results indicate that, in humans, a decrease in skin temperature following exposure to cool environments reduces thermal pain. Suppression of Adelta primary afferent cold fiber activity has been shown to increase cold pain produced by skin cooling. Our current findings may represent the reverse phenomenon, i.e., a reduction in thermal nociceptive transmission by the activation of Adelta cutaneous cold fibers.

Adult↗

Epidural blockade improves substrate utilization after surgery.

The purpose of this study was to test the hypothesis that epidural blockade with local anesthetic improves the anticatabolic effects of glucose after colorectal surgery. Sixteen patients were randomly assigned to undergo a 6-h stable isotope infusion study (3 h fasted, 3 h glucose infusion at 4 mg. kg(-1). min(-1)) on the second postoperative day with or without perioperative epidural blockade. Protein synthesis, breakdown and oxidation, and glucose production and clearance were assessed by L-[1-(13)C]leucine and [6, 6-(2)H(2)]glucose. Epidural blockade did not affect protein and glucose metabolism in the fasted state. Glucose infusion increased glucose clearance (P < 0.05), accompanied by an increase in the respiratory quotient (P < 0.05) and a decrease in leucine oxidation (P < 0.05) only in the presence of epidural blockade. An inverse correlation (r = -0.74, P < 0.05) between changes in glucose clearance and leucine oxidation was observed. In conclusion, epidural blockade facilitates whole body glucose uptake and inhibits endogenous protein oxidation after abdominal surgery, indicating a shift from a protein to a more glucose-dominated substrate utilization.

Aged↗

Uncoupling protein-2 and -3 messenger ribonucleic acids in adipose tissue and skeletal muscle of healthy males: variability, factors affecting expression, and relation to measures of metabolic rate.

Mitochondrial uncoupling protein-2 and -3 (UCP2 and UCP3) may be involved in the modulation of resting metabolic rate and energy balance. To investigate their variability, the influence of this on the variability of energy expenditure, and potential regulatory factors of the expression of the corresponding genes, we measured their messenger ribonucleic acids (mRNAs) in muscle and white adipose tissue of lean, healthy men and correlated the abundance of these mRNAs (attomoles per microg total RNA) with measures of resting metabolic rate, hormone levels (thyroid hormones, insulin, glucagon, leptin, and catecholamines), and fuels potentially involved in energy balance regulation. We also investigated whether the thiazolidinedione, troglitazone, stimulates UCP2 and UCP3 mRNA levels to follow up on the observation that this antidiabetic drug increases the levels of expression in cultured cells. We found UCP2 and UCP3 mRNA levels to be highly variable and poorly correlated with measures of energy expenditure and with most factors affecting energy balance. Only nocturnal urinary norepinephrine excretion could explain a significant fraction of the variability in both UCP2 and UCP3 expression in muscle, but not adipose tissue. Thyroid hormone and norepinephrine excretion were found to contribute to the variability of resting metabolic rate, but this could not be explained by an effect on UCP mRNAs. Troglitazone affected neither the expression of UCPs nor the hormones or the measures of metabolic rate investigated. In conclusion, our results show that the expression of UCP2 and UCP3 genes is quite variable in healthy males and that this variability does not explain that in resting energy expenditure, and suggest that sympathetic activity is an important potential regulator of the expression of these proteins in skeletal muscle. However, the data do not support the concept that regulation of the expression of these genes is the most important level of control of UCP3 and UCP2 functions, and other levels of control have to be invoked.

Adipose Tissue↗

Patterns of systolic stress distribution on mitral valve anterior leaflet chordal apparatus. A structural mechanical theoretical analysis.

Increasing diffusion and complexity of mitral valve repair procedures may prompt an interest in the evaluation of the patterns of stress distribution on the chords, which are, from the structural mechanical point of view, the weakest element of valve apparatus. This theoretical analysis concentrates in particular on the mitral valve anterior leaflet. As is known, the vast majority of the chordae are attached to the anterior leaflet within the coaptation area; during systole they are then necessarily parallel, aligned along the same plane as that of the leaflets' coaptation surface, to which they are attached; moreover the thickness of the chordae increases significantly from the marginal chordae to the more central ones. In normal conditions during systole the progressively wider coaptation surface causes the increasing stress to be supported by an increasing number of progressively thicker chords, which are substantially parallel and aligned on the coaptation surface plane in such a way that they can share the stress between them, according to their thickness; in other words chords form a multifilament functional unit which enrolls elements of increasing thickness in response to the mounting stress. The geometrical modifications of the valve apparatus architecture (annulus dilatation, leaflet retraction, chordal elongation or retraction) often associated with valve insufficiency due to chordal rupture, have the common result of causing, during systole, a radial disarrangement of the direction of most of the secondary chordae which are no longer parallel, aligned on the coaptation surface plane. Due to the negligible elastic module of the valve leaflet, in this new arrangement the various chordae cannot share the stress between themselves as they do in a normal physiological situation; on the contrary the thinner chordae nearer to the free margin are also loaded with the peak systolic stress, thus generating conditions favoring their rupture. It can, therefore, be hypothesized that the anatomopathological picture of valve insufficiency due to chordal rupture may be the final event of a series of geometrical modifications of valve apparatus architecture, the common consequence of which is to load thinner marginal chords with peak systolic stress from which they are normally spared, thus favoring their rupture.

Animals↗

Time of peritoneal cavity exposure influences postoperative glucose production.

PURPOSE: To examine the effect of the duration of peritoneal cavity exposure on glucose metabolism after abdominal surgery. METHODS: In eight otherwise healthy patients (ASA 1) with uterine myoma, endogenous glucose production (Ra glucose) was measured immediately before and two hours after abdominal hysterectomy by a stable isotope dilution technique using primed continuous infusions of [6,6-2H2]-glucose. Plasma concentrations of glucose, lactate, insulin, glucagon, cortisol, epinephrine and norepinephrine were determined before, during (5 and 60 min after peritoneal incision, skin closure) and two hours after surgery. Pre- and postoperative glucose clearance was calculated as Ra glucose divided by plasma glucose concentration. RESULTS: Ra glucose increased from 11.8 +/- 1.2 to 16.8 +/- 3.2 micromol x kg(-1) x min(-1) two hours after hysterectomy (P < 0.05) with a correlation between the degree of increase and the time of peritoneal cavity exposure (r = 0.859, P = 0.006). Plasma glucose concentration increased after surgery from 4.7 +/- 0.8 to 8.3 +/- 1.9 mmol x l(-1) (P < 0.05), while glucose clearance decreased from 2.6 +/- 0.4 to 2.1 +/- 0.4 ml x kg(-1) x min(-1) (P < 0.05). Plasma concentrations of cortisol and catecholamines increased after hysterectomy (cortisol from 6 +/- 2 to 31 +/- 7 microg x dl(-1), epinephrine from 25 +/- 14 to 205 +/- 132 pg x ml(-1), norepinephrine from 182 +/- 82 to 377 +/- 132 pg x ml(-1), P < 0.05), whereas plasma lactate, insulin and glucagon concentrations remained unchanged. CONCLUSION: The magnitude of increase of glucose production after abdominal hysterectomy is associated with the duration of peritoneal cavity exposure.

Adult↗

Spinal block levels and cardiovascular changes during post-Cesarean transport.

PURPOSE: Transport after surgery under spinal anesthesia is associated with cardiovascular changes. The extensively vasodilated patient may be unable to compensate for postural blood flow redistribution. This observational study investigated pre- and post-surgery sensory levels as well as hemodynamic changes during the postoperative transfer period. METHODS: One hundred ninety nine women, ASA 1 and 2, undergoing Cesarean section under spinal anesthesia were studied at the end of surgery. Hyperbaric bupivacaine 12-15 mg and morphine 0.25 mg were the agents used. Patients in group A (n = 111) were transferred to the Recovery Room on a stretcher with the upper body flexed 30 degrees head up: patients in group B (n = 88) remained supine during transport. RESULTS: At the end of Cesarean section 95% of patients had upper sensory levels of T4 and higher. In 17.5% the block ascended 2-7 dermatomes compared with the pre-operative level. The incidence of hypotension on arrival in Recovery Room was similar in both groups (group A 10% and group B 9%). CONCLUSION: These results draw attention to the persistence of extensive sympathetic block at the end of Cesarean section. Transport to the Recovery Room was associated with the development of considerable hypotension in 10% of patients and this was unaffected by position. We recommend recording the level of sensory block at the end of surgery and increased monitoring during transport to the Recovery Room.

Adult↗