Combined Vitamin B-12 and Balanced Protein-Energy Supplementation Affect Homocysteine Remethylation in the Methionine Cycle in Pregnant South Indian Women of Low Vitamin B-12 Status

Background: Low-quality dietary protein intake and vitamin B-12 deficiency could interact to decrease methionine transmethylation and remethylation rates during pregnancy and may affect epigenetic modifications of the fetal genome.Objective: The objective of this randomized, partially open-labeled intervention trial was to examine the effect of supplemental high-quality protein and vitamin B-12 on third-trimester methionine kinetics in pregnant Indian women with a low vitamin B-12 status.Methods: Pregnant women with low serum vitamin B-12 concentrations (<200 pmol/L) were randomly assigned to 1 of 3 groups: the first group received balanced protein-energy supplementation of 500 mL milk/d plus a 10-μg vitamin B-12 tablet/d (M+B-12 group; n = 30), the second group received milk (500 mL/d) plus a placebo tablet (M+P group; n = 30), and the third group received a placebo tablet alone (P group; n = 33). Third-trimester fasting plasma amino acid kinetics were measured by infusing 1-¹³C,methyl-²H₃-methionine, ring-²H₅-phenylalanine, ring-²H₄-tyrosine,1-¹³C-glycine, and 2,3,3-²H₃,¹⁵N-serine in a subset of participants. Placental mRNA expression of genes involved in methionine pathways, placental long interspersed nuclear elements 1 (LINE-1) methylation, and promoter methylation levels of vascular endothelial growth factor (VEGF) were analyzed.Results: Remethylation rates in the M+B-12, M+P, and P groups were 5.1 ± 1.7, 4.1 ± 1.0, and, 5.0 ± 1.4 μmol ⋅ kg^-1 ⋅ h^-1, respectively (P = 0.057), such that the percentage of transmethylation remethylated to methionine tended to be higher in the M+B-12 group (49.5% ± 10.5%) than in the M+P group (42.3% ± 8.4%; P = 0.053) but neither differed from the P group (44.2% ± 8.1%; P > 0.1). Placental mRNA expression, LINE-1, and VEGF promoter methylation did not differ between groups.Conclusions: Combined vitamin B-12 and balanced protein-energy supplementation increased the homocysteine remethylation rate in late pregnancy. Thus, vitamin B-12 along with balanced protein-energy supplementation is critical for optimal functioning of the methionine cycle in the third trimester of pregnancy in Indian women with low serum vitamin B-12 in early pregnancy. This trial was registered at clinicaltrials.gov as CTRI/2016/01/006578.

Energy and Protein Supplementation Does Not Affect Protein and Amino Acid Kinetics or Pregnancy Outcomes in Underweight Indian Women

BACKGROUND

In India, the prevalence of low birth weight is high in women with a low body mass index (BMI), suggesting that underweight women are not capable of providing adequate energy and protein for fetal growth. Furthermore, as pregnancy progresses, there is increased need to provide methyl groups for methylation reactions associated with the synthesis of new proteins and, unlike normal-BMI American women, low-BMI Indian women are unable to increase methionine transmethylation and remethylation rates as pregnancy progresses from trimester 1 to 3. This also negatively influences birth weight.

OBJECTIVE

The aim was to determine the effect of dietary supplementation with energy and protein from 12 ± 1 wk of gestation to time of delivery compared with no supplement on pregnancy outcomes, protein kinetics, and the fluxes of the methyl group donors serine and glycine.

METHODS

Protein kinetics and serine and glycine fluxes were measured by using standard stable isotope tracer methods in the fasting and postprandial states in 24 pregnant women aged 22.9 ± 0.7 y with low BMIs [BMI (in kg/m(2)) ≤18.5] at 12 ± 1 wk (trimester 1) and 30 ± 1 wk (trimester 3) of gestation. After the first measurement, subjects were randomly assigned to either receive the supplement (300 kcal/d, 15 g protein/d) or no supplement.

RESULTS

Supplementation had no significant effect on any variable of pregnancy outcome, and except for fasting state decreases in leucine flux (125 ± 7.14 compared with 113 ± 5.06 μmol ⋅ kg(-1) ⋅ h(-1); P = 0.04) and nonoxidative disposal (110 ± 6.97 compared with 101 ± 3.69 μmol ⋅ kg(-1) ⋅ h(-1); P = 0.02) from trimesters 1 to 3, it had no effect on any other leucine kinetic variable or urea, glycine, and serine fluxes.

CONCLUSION

We conclude that in Indian women with a low BMI, supplementation with energy and protein from week 12 of pregnancy to time of delivery does not improve pregnancy outcome, whole-body protein kinetics, or serine and glycine fluxes.

Alleviation of wood smoke-induced lung injury by tachykinin receptor antagonist and hydroxyl radical scavenger in guinea pigs

We recently reported that wood smoke inhalation initially (within 5 min) causes airway injury and subsequently produces both airway and parenchymal injury after a delay (within 2 h). In this study, we investigated the mediator mechanisms of this delayed smoke-induced lung injury in 126 anesthetized and artificially ventilated guinea pigs who received challenges of either air or 40 tidal breaths of wood smoke. Two hours after inhalation, wood smoke produced various injurious responses, including increases in alveolar-capillary permeability, microvascular permeabilities, and histological injury scores, in airway and parenchymal tissues. Pre-treatment given before smoke challenge with CP-96,345 [a tachykinin NK1 receptor antagonist; (2S,3S)-cis-2-(diphenylmethyl)-N-((2-methoxyphenyl)-methyl)-1-aza bicyclo(2.2.2.)-octan-3-amine], dimethylthiourea (a hydroxyl radical scavenger), or a combination of these two drugs largely alleviated both the airway and parenchymal responses, whereas pre-treatment with SR-48,968 [a tachykinin NK2 receptor antagonist; (S)-N-methyl-N(4-(4-acetylamino-4-phenylpiperidino)-2-(3,4-dichlorophenyl)-butyl)benzamide] or a combination of CP-96,344 and SR-48,965 (inactive enantiomers) failed to do so. Post-treatment given at 5 min after smoke challenge with CP-96,345 or dimethylthiourea significantly alleviated the parenchymal responses, while having no effect on the airway responses. Pre-treatment with dimethylthiourea prevented the smoke-induced reduction in airway neutral endopeptidase activity (an enzyme for tachykinin degradation). We concluded that (1) tachykinins and hydroxyl radical play important roles in producing smoke-induced delayed lung injury in guinea pigs, and both may be involved in the spread of injury from the airways to the pulmonary parenchyma, and (2) the contribution of tachykinins is mediated via the activation of tachykinin NK1 receptors, and is associated with the hydroxyl radical-induced inactivation of airway neutral endopeptidase.

Hemodynamic Response of Modified Fluid Gelatin Compared with Lactated Ringer's Solution for Volume Expansion in Emergency Resuscitation of Hypovolemic Shock Patients: Preliminary Report of a Prospective, Randomized Trial

The objective of this study was to compare the cardiac and hemodynamic responses to a rapid infusion of 1000 ml of modified fluid gelatin (group A) or 1000 ml of lactated Ringer's solution (group B) in emergency room patients suffering from shock. This prospective, randomized, open, noncrossover study was performed at a medical center university hospital in a surgical resuscitation room in the emergency department. The subjects were 34 patients with either hypovolemic or neurogenic shock who were admitted to the emergency room. A resuscitation protocol according to Advanced Trauma Life Support (ATLS) with an additional central venous line or Swan-Ganz catheters for hemodynamic monitoring was used. Physical parameters and hemodynamic variables were measured at baseline and 15 minutes, 30 minutes, and 1 hour after the infusion of each fluid. In both groups the mean arterial blood pressure (MAP), systolic and diastolic pressure, central venous pressure (CVP), and pulmonary artery occlusion pressure (PAOP) increased significantly. The CVP and PAOP increased significantly more in the modified fluid gelatin resuscitation group. In patients with traumatic or neurogenic shock due to acute volume deficiency, there was significantly better hemodynamic improvement, judged by CVP and PAOP measurements using the modified fluid gelatin for volume replacement than with lactated Ringer's solution during the first hour of resuscitation.

Ischaemic change of the human intestine after total portal occlusion during liver resection

This is a clinical study of the use of several monitoring techniques to evaluate the effect of total hepatic inflow occlusion on intestinal ischaemia during liver resection. A total of 8 patients was studied. Parameters measured included intestinal oxygen extraction ratio, portal venous and arterial lactate levels and intestinal intramucosal pH (pHi), measured by an intraluminal tonometer. When venous outflow of the intestine was occluded, intestinal oxygen extraction ratio increased and portal venous lactate increased significantly, but arterial lactate did not increase significantly until after 60 minutes of occlusion. Intestinal pHi decreased significantly after 60 minutes. Following release of the occlusion, oxygen extraction and pHi returned to normal in 7 out of 8 patients. The 1 patient who had a persistent decrease in pHi died postoperatively. These findings indicate that a marked drop in pHi after total portal occlusion and persistent low pHi following the release of a portal occlusion are associated with the development of complications and mortality during liver resection.

Ultrasound-guided cannulation of the internal jugular vein for dialysis vascular access in uremic patients

BACKGROUND

A reliable temporary vascular access is always required for hemodialysis when a permanent vascular access is not available. However, techniques for creating temporary vascular accesses remain imperfect. This study utilized the 'SiteRite' ultrasound device to improve both success and complication rates of jugular venous cannulation for temporary access.

METHODS

This prospective, comparative study recruited 104 uremic patients receiving ultrasound-guided and 86 patients undergoing landmark-guided percutaneous internal jugular venous cannulation of dual-lumen dialysis catheters. Success rate, number of puncture attempts, access time, and the complication rate of the ultrasound technique, in comparison with the landmark-guided technique, were studied.

RESULTS

The ultrasound-guided cannulation was superior to the external landmark-guided cannulation in overall success rate (99.0 vs. 86.0%, p < 0.01), success rate of the first puncture attempt (80.8 vs. 34.9%, p < 0.01), average puncture (access) times (15.8 vs. 43.7 s, p < 0.01), puncture trials (1.39 vs. 2.58, p < 0.01), and traumatic complication rate (1.9 vs. 1 1.6%, p = 0.015). The incidence of infective complications for the ultrasound group was not different from that of the landmark-guided groups (2.9 vs. 2.3%, p = 0.589).

CONCLUSION

The ultrasound-guided technique offers both safety and convenience in inserting jugular venous dialysis catheters. It represents a valuable technique in creating temporary dialysis hemoaccesses.

Tumor necrosis factor gene polymorphism and septic shock in surgical infection

OBJECTIVES

To evaluate the relationship of the genotype distribution of the tumor necrosis factor (TNF)-alpha polymorphism with regard to the plasma TNF-alpha concentration and the development of septic shock as well as mortality of infected patients in a surgical intensive care unit (SICU).

DESIGN

A total of 112 postoperative critically ill infected patients were prospectively enrolled.

SETTING

SICU of a tertiary university-affiliated medical center.

PATIENTS

Patients who were consecutively admitted to the SICU because of surgical infection with sepsis.

INTERVENTION

Blood sampling.

MEASUREMENTS AND MAIN RESULTS

Blood sample was obtained 24 hrs after intensive care unit (ICU) admission or within 2 hrs after the onset of septic shock to determine the plasma TNF-alpha level and to analyze the genotype of the biallelic polymorphism of the TNF-alpha.

RESULTS

The allele frequency of the TNF2 in our infected ICU patients was 12%. Forty-two (37.5%) patients admitted fulfilled the criteria of septic shock during their ICU stay. Patients carrying the TNF2 allele were not more likely to develop septic shock, nor did they have a higher mortality rate. In the patients with septic shock, those carrying the TNF2 allele had a significantly higher mortality rate than those with the homozygous TNF1 genotype (92% vs. 62%, p < .05). In those who developed septic shock, the TNF2 allele was significantly associated with higher TNF levels.

CONCLUSION

In patients admitted to SICU with surgical infection, the frequency of TNF2 allele was higher than in the general population. SICU patients with TNF2 allele did not show a higher incidence of developing septic shock, nor was there a higher baseline TNF-alpha level after infection. However, once septic shock had developed, the mortality rate was higher in those patients carrying the TNF2 allele.

Pseudomonas cepacia induced septic shock after propofol--a case report

We report a healthy young female who developed septic shock and multiple organ failure soon after receiving a cosmetic surgery for augmentation of breasts under general anesthesia. Blood cultures yielded the growth of pseudomonas cepacia. We describe the clinical course and investigate the causes of the septic shock. Contamination of propofol, the intravenous anesthetic agent, was suspected.

Development of a new prognostic system and validation of APACHE II for surgical ICU mortality: a multicenter study in Taiwan

BACKGROUND

To develop and to validate a new prognostic prediction system for patients admitted to the surgical intensive care unit (ICU), and to compare its performance with the Acute Physiology and Chronic Health Evaluation (APACHE) II system.

METHODS

The database was derived from three surgical ICUs in three hospitals. For each patient, demographic data, diagnosis, APACHE II score and hospital survival data were collected. The accuracy in outcome prediction of the APACHE II was assessed by means of receiver operating characteristic (ROC) analysis. The new prognostic system was developed by using a multiple logistic regression in the developmental data set and validated with the validation data set.

RESULTS

A total of 1,248 patients were included from three ICUs. The area under the ROC curve was 0.74 for the APACHE II score. The new prognostic system includes 18 variables. Goodness-of-fit tests indicated that the model performed well in the developmental and validation samples (p = 0.235 in the developmental data set and p = 0.297 in the validation set). The area under the ROC curve was 0.84 in the developmental sample and 0.77 in the validation sample for the new prognostic score. The area under the ROC curve was 0.71 in the validation sample for the APACHE II score.

CONCLUSIONS

Although APACHE II correlates with mortality for surgical ICU patients in Taiwan, its accuracy is not as good as in the original study. Mortality prediction performance improved with the use of the new, local scoring system.

Factors affecting gentamicin pharmacokinetics in septic patients

BACKGROUND

This prospective, comparative study was designed to estimate the volume of distribution (Vd) and elimination rate constant (K(e)) of gentamicin and to determine the clinical factors affecting the pharmacokinetics of gentamicin in different stages of sepsis.

METHOD

Seventy-seven critically ill patients treated with gentamicin for gram-negative sepsis were included. These septic patients were divided into hyperdynamic septic and hypodynamic septic groups according to cardiac index. Twenty-seven patients who received postoperative prophylactic gentamicin were recruited as controls.

RESULTS

Fifty-two patients in the hyperdynamic septic group had a significantly larger Vd than those in the hypodynamic septic and control groups. The Vd was correlated significantly with both Acute Physiological Score (APS) (r=0.340, P<0.01) and cardiac index (r=0.394, P<0.01). The K(e) of gentamicin correlated significantly with both blood urea nitrogen (BUN) (r= 0.565, P<0.01) and serum creatinine level (r=0.563, P<0.01).

CONCLUSION

The increased Vd in the septic patients was related to the severity of illness and magnitude of cardiac output. The K(e) of gentamicin was correlated with the serum creatinine level.

Peri-anhepatic phase oxygen kinetics in porcine liver transplantation

BACKGROUND

We applied a liver transplantation animal model to examine the relationship between oxygen delivery and consumption. The presence of pathologic flow-dependent oxygen consumption was investigated during and after the anhepatic phase. The effect of venous-to-venous bypass on oxygen kinetics was evaluated.

METHODS

Twelve pigs were randomly divided into two groups. The non-bypass group consisted of six pigs that were subjected to clamping of the hepatic artery, portal vein, and the superior and inferior vena cava to produce an anhepatic phase. The bypass group consisted of six pigs that underwent vascular clamping and liver transplantation with venous bypass. Hemodynamics, oxygen delivery index (DO2) and oxygen consumption index (VO2) were recorded during the peri-anhepatic phase. Best-fit regression lines were calculated for DO2 vs VO2.

RESULTS

In the pigs without venous bypass, the blood pressure, cardiac index and VO2 dropped significantly after vascular clamping and lactic acidosis developed. In pigs with venous bypass, vascular clamping induced a significant decline of cardiac output and DO2 but VO2 was maintained by a compensatory increase in oxygen extraction ratio. DO2 and VO2 after the release of vascular clamping increased significantly higher than that before vascular clamping. The O2 supply-dependent regression line was drawn from the points below critical oxygen delivery with a slope of 0.232 (95% CI = 0.110-0.354, r2 = 0.50, p = 0.010). The pathologic supply-dependent line was drawn from the points with supranormal DO2 and VO2 with a slope of 0.185 (95% CI = 0.050-0.333, r2 = 0.510, p = 0.029). The slope of the supply-independent line was 0.0089 (95% CI = -0.030-0.050, r2 < 0.009, p = 0.12).

CONCLUSIONS

Oxygen delivery dropped below the critical level and flow-dependent oxygen consumption developed during the anhepatic phase without venous bypass. Venous-to-venous bypass is necessary to maintain a critical DO2 and stable hemodynamics during porcine liver transplantation. Pathologic flow-dependent oxygen consumption developed after the anhepatic phase.

Serum albumin concentration as a prognostic indicator for acute surgical patients

BACKGROUND

Whether or not the rapid reduction in serum albumin concentration in acute surgical patients without evidence of pre-existing energy deficit correlates with outcome has yet to be studied. In this study, we attempted to determine whether albumin infusion or nutritional supplementation can improve outcome for patients with hypoalbuminemia.

METHODS

We retrospectively reviewed 80 non-calorie-deficient patients newly admitted to the surgical intensive care unit of the Veterans General Hospital-Taipei with complete data for serum albumin concentration and APACHE II score within 24 hours from August, 1998, to February, 1994. The relationships between age, sex, diagnosis, reason for intensive care, albumin infusion, hyperalimentation, APACHE II score, serum albumin concentration, days in intensive care and prognosis within three months were analyzed.

RESULTS

Univariate statistical analysis showed that the serum albumin concentration and APACHE II score correlated well with patient survival (p = 0.002 and p = 0.025, respectively). Multivariate analysis showed that hypoalbuminemia was independently associated with patient outcome (p = 0.003). Simple albumin infusion or hyperalimentation for patients with hypoalbuminemia did not improve survival.

CONCLUSIONS

The results suggest that serum albumin concentration appears to be a good prognostic marker for acute surgical patients. While decreased serum albumin concentration may also reflect poor nutritional status, for patients with moderate to severe hypoalbuminemia due to other causes, simple albumin infusion and/or nutritional support did not significantly improve survival. Consequently, aggressive treatment of the underlying disease is far more important.

Effect of transcutaneous electrical nerve stimulation for pain relief on patients undergoing hemorrhoidectomy: prospective, randomized, controlled trial

PURPOSE

Posthemorrhoidectomy pain control remains a challenging problem. Transcutaneous electrical nerve stimulation is known to be effective in the treatment of many diseases. Our aim was to investigate the effect of transcutaneous electrical nerve stimulation on pain relief in patients undergoing hemorrhoidectomy.

METHODS

Sixty patients with symptomatic hemorrhoids were randomly allocated into two groups, the acupoint group (n = 30) and the nonpoint control group (n = 30). Transcutaneous electrical nerve stimulation was applied to those patients who received hemorrhoidectomy, and patient-controlled analgesia was achieved by injection of morphine through ambulatory infusion pumps. The dependent measures in this study were pain score from 0 (no pain) to 10 (agonizing pain), analgesic doses administrated through patient-controlled analgesia, and postoperative complications.

RESULTS

The subjective pain scores evaluated 8, 12, 16, and 24 hours after hemorrhoidectomy in the control group and the acupoint group were 5.9 +/- 0.5 and 4.1 +/- 0.5, 5.7 +/- 0.5 and 3.5 +/- 0.4, 4.1 +/- 0.4 and 2.3 +/- 0.3, and 3.2 +/- 0.4 and 1.9 +/- 0.2, respectively (two-way analysis of variance; P < 0.05). There was a significant difference between treatment groups in morphine use, with 11.6 +/- 2.2 mg in the control group and 6.2 +/- 1.3 mg in the acupoint group (P < 0.05). The acupoint group tended to have less postoperative acute urinary retention (Fisher's exact probability test; P = 0.145) and less need for analgesics than the control group (P = 0.112, Fisher's exact test).

CONCLUSION

Transcutaneous electrical nerve stimulation is effective for pain relief in patients receiving hemorrhoidectomy. Its efficacy and safety could assist outpatient pain management after hemorrhoidectomy.

Peripheral neural modulation of endotoxin-induced hyperventilation

OBJECTIVE

To delineate the role of the peripheral neural reflexes involved in modulating hyperventilation during endotoxemia.

DESIGN

A prospective, randomized, controlled, multigroup study.

SETTING

Research animal laboratory.

SUBJECTS

Adult Sprague-Dawley rats (n=43; 354+/-24 g) of either gender.

INTERVENTIONS

Eight rats received a sham operation on their vagus, carotid sinus, and aortic nerves before the administration of a saline vehicle to serve as the time control. In the endotoxin group, 11 rats received a sham operation before endotoxin challenge. The remaining 24 rats received bilateral vagotomy (n=8), perivagal capsaicin treatment (n=8), or denervation of peripheral chemoreceptors (n=8) before endotoxin challenge. After the breathing pattern returned to a steady state, endotoxin (L-4130, serotype 0111, B4 lipopolysaccharide; 50 mg/kg) was injected into the vein. The rat's respiration was then monitored continuously for 5 hrs or until the animal died.

MEASUREMENTS AND MAIN RESULTS

The respiratory rate and tidal volume did not change over the 5-hr observation period in the time control group. In the endotoxin group, the respiratory rate increased significantly from baseline (135.4%) 2 hrs after endotoxin challenge and increased persistently until the rats died. The tidal volume increased gradually to < or =132.8% of baseline 4 hrs after endotoxin challenge. Bilateral cervical vagotomy and perineural capsaicin treatment of the vagus nerves eliminated the tachypnea response to endotoxin injection. Denervation of the peripheral chemoreceptor accentuated the hyperventilation response to endotoxin, and resulted in the shortest survival time.

CONCLUSIONS

Both lung vagal C-fiber afferents and peripheral chemoreceptors are involved in modulating the hyperventilation response after endotoxin challenge in rat models. Stimulation of vagal C-fiber afferents increased the respiratory rate. Conversely, the role of peripheral chemoreceptors was to restrain the hyperventilatory response and these receptors may play a protective role during endotoxemia.

Anatomical variation of the internal jugular vein and its impact on temporary haemodialysis vascular access: an ultrasonographic survey in uraemic patients

BACKGROUND

Creation of a reliable haemoaccess is a critical problem for practicing nephrologists once haemodialysis has been considered. A double-lumen internal jugular-vein catheter is favoured in most cases requiring temporary haemoaccess. However, numerous complications, even lethal ones, may occur with the cannulating procedure. Using ultrasound, we attempted to describe the occult anatomical variations of vessels which may be responsible for complications.

METHODS

A 'SiteRite' ultrasonographic device was used to inspect the anatomical structure of the internal jugular veins (IJV) in 104 consecutive uraemic patients undergoing creation of internal jugular vein temporary angioaccess. Images of the vessels and demographic data of patients were recorded and analysed.

RESULTS

Anatomical variations of the right and left IJVs were found in 19 (18.3%) and 17 (16.4%) uraemic patients respectively. Unilateral IJV variations were found in 18 patients (17.3%) and bilateral variations were discovered in nine patients (8.7%). A total of 27 patients (26.0%) had IJV anatomical variations that might contribute to difficulty in external landmark-guided IJV cannulation.

CONCLUSIONS

The external anatomical landmarks for cannulating the IJV are not reliable in about one-quarter of uraemic patients. An ultrasound survey on the IJV anatomy is recommended for selecting proper puncture site and reducing risks of insertion complications for IJV dialysis catheters.

Effects of high thoracic epidural anaesthesia on the peripheral airway reactivity in dogs

BACKGROUND

It has been speculated that epidural anaesthesia may induce bronchoconstriction via the mechanism of a sympathetic blockade. However, this hypothesis has not been confirmed by any experimental evidence. Therefore, we investigated the effects of high thoracic epidural anaesthesia with neural sympathetic blockade on basal airway resistance and airway reactivity in response to bronchoconstrictive stimuli in a canine periphery lung model.

METHODS

Acetylcholine (Ach, 8 microg kg[-1] i.v.) or histamine (His, 3 microg kg[-1] i.v.) was administered to 7 anaesthetized mongrel dogs before and after thoracic epidural anaesthesia. Successful neuronal sympathectomy was confirmed by nitroglycerin test. The changes of peripheral airway resistance (Rp), haemodynamics, cardiac output (CO), and the recovery time for Rp from peak returning to baseline in each challenge were studied.

RESULTS

Thoracic epidural anaesthesia altered neither the baseline Rp nor the peak Rp evoked by Ach or His. However, the recovery time of the Rp was prolonged significantly after epidural anaesthesia (P<0.01) and correlated inversely with the CO in response to Ach or His challenge (Ach, r=0.542; His, r=0.651).

CONCLUSIONS

Our results suggest that epidural anaesthesia with neural sympathetic blockade has no influence on the basal peripheral airway resistance; however, it prolongs the airway reactivity to Ach or His challenge, probably by the mechanism of reducing CO.

Magnetic resonance imaging contrast media in the subarachnoid space. A comparison between gadodiamide injection and gadopentetate dimeglumine in an experimental study in pigs

RATIONALE AND OBJECTIVES

The authors studied the neural tolerance and contrast enhancement of a nonionic, gadodiamide injection (gadolinium [Gd]-DTPA-BMA), and an ionic, gadopentetate dimeglumine (Gd-DTPA), contrast medium in the subarachnoid space of the pig.

METHODS

Sixteen experiments were performed in eight pigs. Lumbar and lateral C1-C2 punctures were performed. Ten milliliters of Gd-DTPA-BMA or Gd-DTPA with Gd concentrations varying from of 500 mmol/L to 0.625 mmol/L were injected, in four experiments via the lumbar route and in 12 experiments via the C1-C2 puncture.

RESULTS

Four pigs injected via the C1-C2 puncture with a Gd concentration of 500 mmol/L had signs of somatomotor irritation and all were paretic after 24 hours. No somatomotor effects were observed in the other experiments, where lower concentrations of Gd were used. Marked enhancement of the cerebrospinal fluid with no visible signal differences was obtained with concentrations from 10 to 0.625 mmol/L.

CONCLUSIONS

Both Gd-DTPA-BMA and Gd-DTPA are remarkably well tolerated in the subarachnoid space. In doses relevant for imaging purposes no adverse effects were seen.

[Similarity and synergy of trauma and sepsis: role of tumor necrosis factor-alpha and interleukin-6]

Both trauma and infection cause a rise in body temperature, white blood cell count, acute phase proteins, fluid and sodium retention and negative nitrogen balance. This phenomenon is often described as "acute phase response" or "systemic inflammatory response syndrome" to denote a coordinated systemic response to significant tissue injury and/or microbial invasion. It is generally agreed that the acute phase response is mediated through the interaction of cytokine and neuroendocrine pathways. Tumor Necrosis Factor-alpha (TNF-alpha) and interleukin-6 (IL-6) are two of the major key cytokines involved in the generation of acute phase response. Interleukin-6 are consistently found in septic, trauma and post-operative patients and correlated well with the severity of sepsis or injury. IL-6 is responsible for the fever and metabolic changes in the acute phase. In addition to IL-6, TNF-alpha was proved to be the mediator that orchestrates the hemodynamic and tissue injury in septic shock. TNF-alpha destroys endothelial cells and induces disseminated intravascular coagulation, fluid shift, shock, multiple organ system failure and death. On many clinical occasions, both infection and trauma may happen simultaneously on the same patient. Our study demonstrated that operation on the infected patients would cause a synergistic effect on both TNF-alpha and IL-6 levels. The pulse increase in TNF-alpha and the persistent elevation of IL-6 were responsible for the post-operative unstable clinical condition in the infected patients. Should we block the cytokine signal and inflammatory response that appear to be harmful? Animal studies have shown that the septic shock to endotoxin challenge can be prevented by pretreatment with monoclonal antibody against TNF-alpha. The transcription of TNF-alpha can be blocked with corticosteroid in vivo. The post-operative increase in IL-6 and its related inflammation can be attenuated with corticosteroid, epidural anesthesia and narcotics. However, although blocking the inflammatory response has a beneficial effect of stress free it also eliminates our ability to fight with bacterial infection by lowering our immune response. How to manipulate these cytokines is a question of art more than science.

Perioperative plasma concentrations of tumor necrosis factor-alpha and interleukin-6 in infected patients

OBJECTIVE

To characterize the sequential plasma concentrations of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) and their relationship with the clinical outcome in patients with intra-abdominal infection who underwent surgical intervention.

DESIGN

A prospective, comparative study.

SETTING

Surgical intensive care unit of a university hospital.

PATIENTS

Fifteen patients with surgically proved intra-abdominal infection were included as the infected group. The comparative noninfected group consisted of ten patients who underwent major abdominal surgery without infection.

INTERVENTIONS

Blood samples were obtained from the indwelling arterial catheter before induction of general anesthesia, and 1, 1.5, 2, 3, 4, 6, and 24 hrs after skin incision.

MEASUREMENTS AND MAIN RESULTS

Plasma cytokine concentrations were measured using radioimmunoassay. The hemodynamic and physiologic parameters were recorded for comparison with cytokine concentrations. In the noninfected group, the TNF-alpha concentration was very low throughout the observation period, and the IL-6 concentration increased 4 hrs after skin incision. The infected group had significantly higher TNF-alpha and IL-6 concentrations than the noninfected group. The TNF-alpha concentration increased from 129.2 +/- 46.4 to 1196.0 +/- 445.8 pg/mL and the IL-6 concentration increased from 54.2 +/- 24.3 to 560.3 +/- 187.5 pg/mL 2 hrs after skin incision in the infected group. The postoperative APACHE II score correlated significantly with both peak IL-6 (r2=.39) and peak TNF-alpha (r2=.32) concentrations.

CONCLUSIONS

Both TNF-alpha and IL-6 concentrations increased significantly after surgical intervention in patients with intra-abdominal infection. The pulse increase in TNF-alpha concentration and the persistent increase in IL-6 concentration were related to the poor postoperative clinical condition in infected patients.

Animal experimental myelography in the pig. A comparison between iohexol and iotrolan

RATIONALE AND OBJECTIVES

The authors compared the effects of a nonionic monomeric, iohexol (Omnipaque, 300 mg I/ml), and a nonionic dimeric, iotrolan (Isovist, 300 mg I/ml), contrast medium in the spinal subarachnoid space of the pig.

METHODS

Lumbar and lateral C1-C2 punctures were performed in 10 pigs. Ten milliliters iohexol or iotrolan were injected via the lumbar needle. Blood pressure, electrocardiogram, intravesical pressure, and cerebrospinal fluid pressure were recorded during the injections and at intervals for 4 to 5 hours after the injections. Blood samples were taken at 30, 60, 120, 180, 240, and 300 minutes after the injections and analyzed for iodine concentration.

RESULTS

No changes were seen during the injections, and there were no differences in the blood pressure, cerebrospinal fluid pressure, electrocardiographic recordings, or in the plasma iodine concentrations during the first 4 to 5 hours after the injections. Short-lasting, rhythmic bladder contractions were seen during some injections with both iohexol and iotrolan.

CONCLUSION

Both iohexol and iotrolan were well tolerated, and there was no significant difference between them. and there was no significant difference between them.

The role of flow cytometry in non-resected cervical carcinoma

Flow cytometry (FCM) has a prognostic value for many malignant neoplasms in terms of treatment response rate and survival. However, its role in non-resected cervical carcinoma remains uncertain. We have collected 96 paraffin-embedded specimens taken from non-resected cervical cancer patients treated by radiotherapy (RT) alone between 1984 and 1986. Our data revealed that FCM has little correlation with patients' age, pathological grade and clinical stage. Ploidy pattern and clinical stage correlate significantly with complete remission (CR) rate (p = 0.001 and 0.03). Most diploid or low-stage tumours (IB to IIA) obtained CR after RT alone. The application of an intravaginal extension electron cone (IVEC) (p = 0.019) and CR status (p = 0.0001) yield significant better overall survival (OS) rates than their alternative groups. The Cox regression model has confirmed these two variables as having an independent influence on OS. We thus conclude that both ploidy pattern and S-phase fraction (SPF) predict neither pre-treatment biological behaviour of the tumours nor overall survival. However, ploidy pattern has an independent influence on CR rate.

[Protrusion of thoracic intervertebral disk: report of 11 cases]

The authors reported 11 cases of thoracic intervertebral disk protrusion examined with plane film, myelography, CT and CT-myelography in 11 cases and MR imaging in 3. All of the 11, cases were confirmed by operation. There were 13 protrusions in the 11 cases with the locations of T10-11 in 4, T11-12 in 5 cases and T12-L1 in 4. 9 protrusions fell into central type, 1 into paracentral type and 1 into lateral type. The clinical symptoms were prominent with all 11 cases, however, most primary clinical diagnoses were erroneously given as lumber intervertebral disk protrusions and even the disorders of heart, lung, alimentary tract and urinary system. It was concluded that the main causes of the misdiagnosis included: (1) not easily to think of this entity for the clinic physicians due to its low incidence, (2) the untypical clinical manifestations. The authors considered that the exam method with the highest accuracy is CT-myelography.

Seizure after reversal of benzodiazepine treatment with flumazenil: a report of two cases

Two patients developed seizure immediately after flumazenil administration that aimed to reverse the prolonged sedative effect of diazepam. The use of benzodiazepine for sedation in ICU may mask valuable information relevant to an ongoing pathological change. The seizure in our patients seemed most likely to result from septic encephalopathy which was unmasked by flumazenil. However, flumazenil has the potential to provoke seizure and should be used with caution.

The role of submucosal oedema in increased peripheral airway resistance by intravenous volume loading in dogs

Pulmonary congestion leads to an increase in airway resistance. It is still unknown whether this is due to vascular engorgement or to submucosal oedema. The present study was designed to determine the relative contribution of these two potential mechanisms. We examined the effect of intravenous volume loading on canine peripheral airway resistance (Rp). Bronchoscopes were wedged in contralateral sublobar segments and used to record Rp during rapid infusion of normal saline. Volume loading with normal saline increased pulmonary capillary wedge pressure (PCWP) and Rp. Unlike normal saline, dextran 70 did not increase Rp when infused at a rate that produced similar changes in PCWP. During infusion of normal saline, delta Rp was significantly enhanced in lung segments previously challenged with dry air when compared to contralateral control lungs, unexposed to dry air, and the use of dextran 70 significantly reduced this effect. Vasoconstriction with phenylephrine significantly decreased baseline Rp, but did not completely reverse the effect of fluid infusion. In addition, in lung segments exposed to dry air, delta Rp was significantly greater after volume loading and treatment with phenylephrine when compared to contralateral control lung. Finally, muscarinic receptor blockade was ineffective in preventing Rp from increasing during infusion of normal saline. Our results suggest that volume loading-induced increases in Rp are not caused by either vascular engorgement or the stimulation of muscarinic receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

The Autonomic Nervous System Modulates Dry Air-induced Constriction in the Canine Lung Periphery

To determine the modulatory role of the autonomic nervous system on dry air-induced bronchoconstriction (AIB) in the canine lung periphery, we examined the effect of cholinergic, alpha- and beta-adrenergic, and total autonomic ganglionic blockade on AIB. Pretreatment with atropine significantly attenuated AIB by approximately 30%, indicating that AIB is partially mediated via a vagal reflex. Pretreatment with either phentolamine or propranolol did not affect AIB, indicating that alpha- and beta-adrenoceptors, respectively, were not activated in response to dry air challenge. In contrast, pretreatment with hexamethonium significantly potentiated AIB. In addition, exogenous vasoactive intestinal peptide (VIP), a potential neurotransmitter for the nonadrenergic-noncholinergic (NANC) inhibitory system, significantly inhibited AIB. We conclude that (1) neither alpha- or beta-adrenergic efferents are activated during dry air challenge, (2) total autonomic blockade potentiates the response to dry air, and (3) VIP attenuates AIB. Based on these observations, we speculate that NANC inhibitory activity may be stimulated during dry air challenge and antagonizes AIB.

The hemodynamics and clinical effects of labetalol in hypotensive anesthesia

Labetalol is a relatively new and unique hypotensive agent that has both alpha- and beta-adrenoceptor blocking properties. 12 patients in fit physical condition who underwent elective oral surgery were subject to hypotensive anesthesia with labetalol to assess the hemodynamic aspects and clinical effects of the drug. All of them had their anesthesia maintained with halothane and N2O in 50% O2 supplemented by fentanyl and vecuronium. Initiation of deliberate hypotension was made with intravenous bolus of labetalol at 0.5 mg/kg and the ideal level of mean arterial pressure at 55 +/- 5 mm Hg was maintained with adjustment of the concentration of halothane. At the termination of deliberate hypotension, the blood pressure was recuperated to the baseline level by lowering the concentration of halothane and administration of 0.5-0.6 mg intravenous atropine. Our results showed that the total dose of labetalol used was 44 +/- 13 mg and blood loss amounted to 354 +/- 136 ml. Important changes of hemodynamic parameters before and after labetalol included the fall of mean BP, HR, mean PAP, CI, LVSWI, SVRI, PVRI and O2 delivery and the increasing of O2 extraction. As to CVP, PCWP, SVI, O2 consumption and shunting the alterations were minimal. Blood gas analysis showed that, save a slight fall of pH indicating mild metabolic acidosis, the PaO2 and PaCO2 remained unchanged following the use of labetalol. Labetalol-induced hypotension could be effectively reversed by using of atropine as shown in our study and all the patients recovered uneventfully from hypotensive anesthesia. They were entirely free from any complication or sequela relevant to the deliberate hypotension after one year's follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)