Entrainment of the body temperature rhythm in rats: effect of color and intensity of environmental light.

The daily rhythm in body temperature in rats was continuously monitored during exposure to low-intensity environmental illumination of various colors in the visible and near-ultraviolet spectrum. The ability of phase shifts in the lighting schedule to induce concomitant changes in the rhythm was used to determine the spectral sensitivity of the retinal photoreceptor systems mediating rhythm entrainment. Green light (lambda = 530 +/- 45 nanometers) was most potent, and red (lambda = 660 +/- 19 nanometers) and ultraviolet (lambda = 360 +/- 34 nanometers) were least potent in entraining the temperature rhythm.

Association of cocaine- and amphetamine-regulated transcript-immunoreactive elements with thyrotropin-releasing hormone-synthesizing neurons in the hypothalamic paraventricular nucleus and its role in the regulation of the hypothalamic-pituitary-thyroid axis during fasting.

Because cocaine- and amphetamine-regulated transcript (CART) coexists with alpha-melanocyte stimulating hormone (alpha-MSH) in the arcuate nucleus neurons and we have recently demonstrated that alpha-MSH innervates TRH-synthesizing neurons in the hypothalamic paraventricular nucleus (PVN), we raised the possibility that CART may also be contained in fibers that innervate hypophysiotropic thyrotropin-releasing hormone (TRH) neurons and modulate TRH gene expression. Triple-labeling fluorescent in situ hybridization and immunofluorescence were performed to reveal the morphological relationships between pro-TRH mRNA-containing neurons and CART- and alpha-MSH-immunoreactive (IR) axons. CART-IR axons densely innervated the majority of pro-TRH mRNA-containing neurons in all parvocellular subdivisions of the PVN and established asymmetric synaptic specializations with pro-TRH neurons. However, whereas all alpha-MSH-IR axons in the PVN contained CART-IR, only a portion of CART-IR axons in contact with pro-TRH neurons were immunoreactive for alpha-MSH. In the medial and periventricular parvocellular subdivisions of the PVN, CART was co-contained in approximately 80% of pro-TRH neuronal perikarya, whereas colocalization with pro-TRH was found in <10% of the anterior parvocellular subdivision neurons. In addition, >80% of TRH/CART neurons in the periventricular and medial parvocellular subdivisions accumulated Fluoro-Gold after systemic administration, suggesting that CART may serve as a marker for hypophysiotropic TRH neurons. CART prevented fasting-induced suppression of pro-TRH in the PVN when administered intracerebroventricularly and increased the content of TRH in hypothalamic cell cultures. These studies establish an anatomical association between CART and pro-TRH-producing neurons in the PVN and demonstrate that CART has a stimulatory effect on hypophysiotropic TRH neurons by increasing pro-TRH gene expression and the biosynthesis of TRH.

Peripheral vascular endothelial function testing as a noninvasive indicator of coronary artery disease.

OBJECTIVES: We studied whether assessment of endothelium-dependent vasomotion (EDV) with brachial artery ultrasound (BAUS) imaging predicts the presence or absence of coronary artery disease (CAD) as defined by exercise myocardial perfusion imaging (ExMPI). BACKGROUND: Abnormalities in EDV can be detected in arteries before the development of overt atherosclerosis, and its presence may predict poor long-term prognosis. Brachial artery ultrasound during reactive hyperemia is a noninvasive method of assessing peripheral EDV. METHODS: Clinically-indicated ExMPI along with BAUS were performed in 94 subjects (43 women, 51 men). Coronary artery disease was defined by myocardial ischemia or infarction on single photon emission computed tomography images. Flow-mediated dilation (FMD) after upper arm occlusion was defined as the percent change in arterial diameter during reactive hyperemia relative to the baseline. RESULTS: Subjects with CAD by ExMPI (n = 23) had a lower FMD (6.3 +/- 0.7%) than those without CAD by ExMPI (n = 71) (10.5 +/- 0.6%; p = 0.0004). Flow-mediated dilation was highly predictive for CAD with an odds ratio of 1.32 for each percent decrease in FMD (p = 0.001). Based on a receiver-operator analysis, an FMD of 10% was used as a cut-point for further analysis. Twenty-one of 23 subjects who were positive for ExMPI had an FMD < 10% (sensitivity 91%), whereas only two of 40 subjects with an FMD > or =10% were ExMPI-positive (negative predictive value: 95%). There was a correlation between the number of cardiac risk factors and FMD. Individuals with an FMD < 10% exercised for a shorter duration than those with an FMD > or =10% (456 +/- 24 vs. 544 +/- 31 s, respectively; p = 0.02). CONCLUSIONS: Assessment of EDV with BAUS has a high sensitivity and an excellent negative predictive value for CAD and, thus, has the potential for use as a screening tool to exclude CAD in low-risk subjects. Further standardization of BAUS is required, however, before specific cut-points for excluding CAD can be established.

Antiplatelet agents and survival: a cohort analysis from the Studies of Left Ventricular Dysfunction (SOLVD) trial.

OBJECTIVES: This study sought to evaluate the relation between antiplatelet agent (APA) use and survival and morbidity from cardiac disease in patients with left ventricular (LV) systolic dysfunction. BACKGROUND: APAs play an important role in the prevention and treatment of coronary disease. Their effects in patients with LV systolic dysfunction are unknown. METHODS: We reviewed data on APA use in 6,797 patients enrolled in the Studies of Left Ventricular Dysfunction (SOLVD) trial and analyzed the relation between their use and all-cause mortality as well as the combined end point of death or hospital admission for heart failure (HF). We used Cox regression to adjust for differences in baseline characteristics and to test for the interaction between APA use and selected patient variables in relation to outcome. RESULTS: APA use (46.3% of patients) was associated with significantly reduced mortality from all causes (adjusted hazard ratio [HR] 0.82, 95% confidence interval [CI] 0.73 to 0.92, p = 0.0005) and reduced risk of death or hospital admission for HF (adjusted HR 0.81, 95% CI 0.74 to 0.89, p < 0.0001) but was not influenced by trial assignment, gender, LV ejection fraction, New York Heart Association class or etiology. A strong interaction was observed among APA use, randomization group and all-cause mortality. The association between APA use and survival was not observed in the enalapril group, nor was an enalapril benefit on survival detectable in patients receiving APAs at baseline. However, randomization to enalapril therapy significantly reduced the combined end point of death or hospital admission for HF in APA users. CONCLUSIONS: In patients with LV systolic dysfunction, use of APAs is associated with improved survival and reduced morbidity. This association is retained after adjustment for baseline characteristics. APA use is associated with retained but reduced benefit from enalapril.

Warfarin anticoagulation and survival: a cohort analysis from the Studies of Left Ventricular Dysfunction.

OBJECTIVES: We sought to evaluate the relation between warfarin anticoagulation and survival and morbidity from cardiac disease in patients with left ventricular (LV) dysfunction. BACKGROUND: Warfarin anticoagulation plays a major role in the management of patients who have had a large myocardial infarction and in those with atrial fibrillation. However, its use in patients with LV systolic dysfunction has been controversial. METHODS: We reviewed data on warfarin use in 6,797 patients enrolled in the Studies of Left Ventricular Dysfunction (SOLVD) trial and analyzed the relation between warfarin use and all-cause mortality, as well as the combined end point of death or hospital admission for heart failure. We used Cox regression to adjust for differences in baseline characteristics and to test for the interaction between warfarin use and selected patient variables in relation to outcome. RESULTS: On multivariate analysis, use of warfarin was associated with a significant reduction in all-cause mortality (adjusted hazard ratio [HR] 0.76, 95% confidence interval [CI] 0.65 to 0.89, p = 0.0006) and in the risk of death or hospital admission for heart failure (HR 0.82, 95% CI 0.72 to 0.93, p = 0.0002). Risk reduction was observed when each trial or randomization arm was analyzed separately, as well as in both genders. It was not significantly influenced by the presence of atrial fibrillation, age, ejection fraction, New York Heart Association functional class or etiology. CONCLUSIONS: In patients with LV systolic dysfunction, warfarin use is associated with improved survival and reduced morbidity. This association is primarily due to a reduction in cardiac events and does not appear to be limited to any particular subgroup.

Reduced kidney function and anemia as risk factors for mortality in patients with left ventricular dysfunction.

OBJECTIVES: We sought to evaluate the relationship between the level of kidney function, level of hematocrit and their interaction on all-cause mortality in patients with left ventricular (LV) dysfunction. BACKGROUND: Anemia and reduced kidney function occur frequently in patients with heart failure. The level of hematocrit and its relationship with renal function have not been evaluated as risk factors for mortality in patients with LV dysfunction. METHODS: We retrospectively examined the Studies Of LV Dysfunction (SOLVD) database. Glomerular filtration rate (GFR) was predicted using a recently validated formula. Kaplan-Meier survival analyses were used to compare survival times between groups stratified by level of kidney function (predicted GFR) and hematocrit. Cox proportional-hazards regression was used to explore the relationship of survival time to level of kidney function, hematocrit and their interaction. RESULTS: Lower GFR and hematocrit were associated with a higher prevalence of traditional cardiovascular risk factors. In univariate analysis, reduced kidney function and lower hematocrit, in men and in women, were risk factors for all-cause mortality (p < 0.001 for both). After adjustment for other factors significant in univariate analysis, a 10 ml/min/1.73 m(2) lower GFR and a 1% lower hematocrit were associated with a 1.064 (95% CI: 1.033, 1.096) and 1.027 (95% CI: 1.015, 1.038) higher risk for mortality, respectively. At lower GFR and lower hematocrit, the risk was higher (p = 0.022 for the interaction) than that predicted by both factors independently. CONCLUSIONS: Decreased kidney function and anemia are risk factors for all-cause mortality in patients with LV dysfunction, especially when both are present. These relationships need to be confirmed in additional studies.

In vivo axial dynamization of canine tibial fractures using the Securos external skeletal fixation system.

Bilateral transverse mid-shaft tibial osteotomies, with a 4-mm gap, were performed in purpose-bred research dogs and stabilized using a Securos Type 2 external skeletal fixotor (ESF). Full (100%) axial dynamization of one randomly selected ESF in each dog was performed at 31 days postoperatively. Caudo-cranial radiographs were obtained at weekly intervals, which were qualitatively and quantitatively evaluated (densitometry and ImageJ analysis). The dogs were euthanatized 13 weeks postoperatively, at which time dual energy x-ray absorptiometry (DEXA), peripheral quantitative computed tomography (pQCT), mechanical testing in torsion, and qualitative histological analysis were performed. A two-tailed paired Student's t-test was performed for statistical analysis of all parameters of interest, with significance set at p < 0.05. Three of five dynamized bones bridged quicker, and four of five dynamized bones appeared to have greater callus formation, however, statistically significant differences could not be definitively determined. Statistically significant differences were not found with densitometry (any time frame), DEXA, pQCT, torsional stiffness or maximum torque. Despite the lack of statistically relevant data, trends were observed with larger callus size and density in the dynamized tibiae. The dynamized tibiae appeared to fracture more consistently outside of the area of the healing callus as compared to the control tibiae. Histological evaluation showed greater remodelling in four of five control limbs when compared to the dynamized limb. Dynamization at 31 days post-operatively may delay bone remodelling, despite a trend towards a larger callus size. The results of this study failed to show a definitive role for early full axial dynamization.

Neuropeptide Y has a central inhibitory action on the hypothalamic-pituitary-thyroid axis.

Recent evidence suggests that neuropeptide Y (NPY), originating in neurons in the hypothalamic arcuate nucleus, is an important mediator of the effects of leptin on the central nervous system. As these NPY neurons innervate hypophysiotropic neurons in the hypothalamic paraventricular nucleus (PVN) that produce the tripeptide, TRH, we raised the possibility that NPY may be responsible for resetting of the hypothalamic-pituitary-thyroid (HPT) axis during fasting. To test this hypothesis, the effects of intracerebroventricularly administered NPY on circulating thyroid hormone levels and proTRH messenger RNA in the PVN were studied by RIA and in situ hybridization histochemistry, respectively. NPY administration suppressed circulating levels of thyroid hormone (T(3) and T(4)) and resulted in an inappropriately normal or low TSH. These alterations were associated with a significant suppression of proTRH messenger RNA in the PVN, indicating that NPY infusion had resulted in a state of central hypothyroidism. Similar observations were made in NPY-infused animals pair fed to the vehicle-treated controls. These data are reminiscent of the effect of fasting on the thyroid axis and indicate that NPY may play a major role in the inhibition of HPT axis during fasting.

Report of a planning conference concerning an international network of food data systems (INFOODS).

A small international planning conference on the topic of "An International Network of Food Data Systems" was held on January 30 to February 5, 1983, at the Rockefeller Conference and Study Center, in Bellagio, Italy. It was sponsored through the Food, Nutrition and Poverty Subprogramme of the United Nations University and supported by various US government agencies, private foundations, and the food industry. Participants included representatives from FAO, WHO, IUNS, and IUFoST. The purpose was to explore the needs for, and current limitations of, food composition data bases, especially in the international context, and to propose what was needed. The conference focused on the design and scope of an organization to be called INFOODS (International Network of Food Data Systems) which would promote international participation and cooperation in the acquisition and interchange of quality data on the nutrient composition of foods, beverages, and their ingredients in forms appropriate to meet the needs of government agencies; nutrition scientists; health and agriculture professionals; policy makers and planners; food producers, processors, and retailers; consumers. The conference identified the more important aspects of INFOODS to include: 1) a network of regional data centers; 2) an organizational/administrative framework for various expert task forces; 3) the generator and repository of special international data bases; 4) the stimulator of national data base programs; 5) a general and specific resource for persons and organizations interested in food composition data on a worldwide basis.(ABSTRACT TRUNCATED AT 250 WORDS)

Determination of protein allowances in human adults from nitrogen balance data.

The problem of predicting human protein requirements is examined in detail. Three methods from the literature are shown to represent a logical sequence wherin each takes into account more sources of variation than does the previous one. These are the single level method and two versions of the multiple level method, all of which assume a population response curve. A fourth method is proposed as the next step in this sequence. This method calculates a response curve for each individual and works with the individual requirements. Since each method makes fewer assumptions about the data and, therefore, about the biological situation of population protein needs, each method gives successively larger protein allowance values, while at the same time identifying the sources of variability and uncertainty in these estimates.

Retrospective analysis of data from five long-term, metabolic balance studies: implications for understanding dietary nitrogen and energy utilization.

Daily urinary nitrogen (N) excretion and body weight data of 42 healthy young adults, who received constant, adequate diets for up to 90 days, and maintained constant level of physical activity, were examined retrospectively. From the N excretion data, it was determined that, when corrected for long-term trends, daily variability was random and much larger than variability due to the long-term trends. Thus, N balance data based on commonly used diet periods of about 2 wk adequately estimates population variability. Body weight data for most subjects showed significant changes and many subjects experienced persistent linear changes throughout the entire experimental period. Thus, for most healthy young adults, neither dietary-induced thermogenesis nor changes in the efficiency of energy utilization appears to play a quantitatively important role in the maintenance of body weight (and body composition) in response to relatively modest discrepancies between the level of food intake and energy intake needed to balance initial total energy expenditure. The key importance of food intake regulation and/or physical activity in weight maintenance is emphasized by these findings.

An analysis of temporal patterns in urinary nitrogen excretion of young adults receiving constant diets at two nitrogen intakes for 8 to 11 weeks.

The temporal pattern of daily urinary nitrogen (UN) excretion was investigated in 21 young adult men and women who participated in two metabolic studies involving constant diets and lasting 8 to 11 weeks. For one group (16 subjects), nitrogen (N) intake was about 280 mg N/kg per day (mixed animal and plant protein sources) for 8 weeks; for the second group (five subjects), N intake was about 90 mg N/kg per day (egg protein) for 11 weeks. Two mathematical models were examined to determine how well they described the variations in UN. The first modeled only random variability while the second added a component of serial correlation (correlation between successive daily observations). After correcting the UN data for linear trend, to minimize effects of possible alterations in body composition, only two of the 21 subjects showed significant serial correlation of daily UN. Moreover, it is shown that any serial correlation undetectable in these data would not be of practical importance in estimating UN levels in short-term dietary experiments. It is concluded that the interpretation of metabolic N balance measurements involving constant N intakes over relatively short dietary periods in not complicated by cyclic, time-dependent variations in UN.

Change of urinary nitrogen excretion in response to low-protein diets in adults.

Data from nitrogen balance studies in young men and elderly women were analyzed for the pattern of urinary nitrogen excretion after the subjects had changed from an adequate to an essentially protein-free diet. The single exponential equation: y = P1e-p2t+P3, provided an adequate fit of the data, suggesting that a single-pool model describes the adaptive decline in urinary nitrogen excretion under these dietary conditions. Comparisons of the estimated parameters showed that the fractional rate constant, P2, was the same for both the young men and elderly women, but that the other coefficients differed between the two groups depending upon whether they were expressed per day, per kg of body weight, per unit creatinine excreted, or per kg of body cell mass. The length of time between the change in diet and the attainment of a new equilibrium in urinary nitrogen excretion (ts, or time to stability) is defined as ts = 1/p2 loge(p1/s) where s is the standard error of the fit. The average time to stability was the same in both groups (4.5 days), and 95% of the subjects reached the new equilibrium in nitrogen output within 8 days.

Evaluation of the protein quality of an isolated soy protein in young men: relative nitrogen requirements and effect of methionine supplementation.

The protein nutritional value of an isolated soy protein (Supro-620) was evaluated in a series of nitrogen balance studies in healthy young male MIT students. Experiment 1 involved giving eight subjects graded intakes of the isolated soy protein while seven additional subjects received egg protein. Mean nitrogen intake required for N balance for the isolated soy protein and the egg protein were not significantly different (p greater than 0.1). In experiment 2, nine subjects received soy and the effects on N balance at various levels of L-methionine supplementation were studied. In experiment 3 eight subjects each were studied at two nitrogen intake levels of isolated soy protein/kg/day with methionine supplementation, and an unsupplemented egg protein period included. Results from experiment 2 and 3 at an 82 mg N/kg/day test level showed that N balance for 1.6% supplementation was significantly below that of unsupplemented egg while 1.1% and unsupplemented soy were indistinguishable from egg. No beneficial effects of methionine supplementation were observed when the test nitrogen intake level was 128 mg N/kg/day. These results indicate that for healthy adults, the isolated soy protein is of high nutritional quality, comparable to that of animal protein sources, and that the methionine content is not limiting for adult protein maintenance.

Diurnal variations in plasma concentrations of tryptophan, tryosine, and other neutral amino acids: effect of dietary protein intake.

The effect of dietary protein content on the diurnal variations in plasma neutral amino acid levels was studied in normal human subjects. For three consecutive 5-day periods, subjects consumed diets containing 0, 75, or 150 g of egg protein per day. Blood samples were drawn at 4-hr intervals on the 4th and 5th days of each period. Consumption of the protein-free diet caused plasma concentrations of all amino acids studied to fall in the late morning and afternoon, while the 150-g protein diet elicited increases in these levels during the daytime. Ingestion of the diet containing 75 g of egg protein tended to diminish the amplitudes of the daily rhythms in plasma amino acid levels, but most amino acids still exhibited small but significant elevations late in the evening. At all times of day, plasma concentrations of the large neutral amino acids studied (i.e., aromatic and branched-chain amino acids, and methionine) varied directly with the protein content of the diet. In contrast, the relationships between dietary protein content and the plasma concentrations of glycine and alanine, two small neutral amino acids, were inverse. The ratios of plasma tryptophan, tyrosine, and phenylalanine levels to the sum of the concentrations of other large neutral amino acids tended to fall as the protein content of the diet was increased. The corresponding ratio for valine increased as protein was added to the diet, while the leucine and isoleucine ratios were not correlated with dietary protein content. Since diet-induced changes in plasma trypotphan and tyrosine ratios in animals are known to cause parallel alterations in brain tryptophan and tyrosine levels, and thus in the rates of brain serotonin and catecholamine synthesis, our data suggest that ingestion of carbohydrates and protein may also normally affected brain monoamine synthesis in humans.

Diurnal variations in plasma neutral amino acid concentrations among patients with cirrhosis: effect of dietary protein.

The effect of varying dietary protein content on the daily rhythms in plasma neutral amino acid concentrations was studied in patients with chronic cirrhosis. For two consecutive 5-day periods, subjects consumed diets containing either 0 or 75 g of protein per day. Blood samples were drawn at 4-hr intervals on the 4th and 5th days of each dietary period. For most of the neutral amino acids, the changes in plasma concentration associated with time of day or with variations in dietary protein content were similar to those observed previously in normal subjects. Ingestion of the protein-free diet caused significant reductions in the daytime level of all amino acids studied, except for tryptophan, the concentration of which did not change during the 24-hr period. Ingestion of the 75-g protein diet caused plasma levels of most of theamino acids to increase slightly during the day; these increments were not statistically significant for tryptophan, tyrosine, leucine, and methionine. The absolute plasma concentrations of most of the neutral amino acids were also in the normal range; exceptions included methonine, tyrosine, and phenylalanine, whose plasma levels were significantly elevated above normal valves. The plasma ratios of tryptophan, tyrosine, and phenylalanine concentrations to the sum of the concentrations of other large neutral amino acids increased during the day uhen the protein-free diet was ingested; this effect was moderated by the addition of protein to the food. The plasma ratios for the branched-chain amino acids were depressed below normal; those for tyrosine, phenylalanine, and methionine were significantly increased. The plasma tryptophan ratio was within the normal range. These findings provide a basis for anticipating that the uptake from blood into brain of several of the large neutral amino acids may be modified in patients with chronic cirrhosis.

A long-term metabolic balance study in young men to assess the nutritional quality of an isolated soy protein and beef proteins.

To evaluate the capacity of an isolated soy protein to maintain long-term protein nutritional status in healthy young adult men, an 84-day metabolic balance experiment was conducted in eight subjects. The sole source of protein intake was provided by the isolated soy protein, given at a level of 0.8 g (N X 6.25) per kg per day. In a second and similar study, four young men received 0.8 g protein and three subjects 0.68 g protein per kg per day from beef proteins for 60 to 81 days. Body weight, nitrogen balance, blood chemistries, and body composition (whole body 40K) were monitored throughout each study. Body nitrogen balances were maintained within the range of N equilibrium in both diet groups. Body cell mass, as judged from 40K measurements, did not reveal any deterioration in protein nutritional status. These observations confirm the prediction, derived from previous short-term. N balance studies, that the nutritional quality of isolated soy protein is high and that this plant protein can serve as the sole source of essential amino acids and nitrogen for protein maintenance in adults.

Prognostic significance of ventricular blood in supratentorial hemorrhage: a volumetric study.

We reviewed CTs from 47 patients with 48 spontaneous, supratentorial brain hemorrhages to determine the effect of ventricular blood on outcome. We correlated volumetric analysis of the parenchymal (P) and ventricular (V) blood, as well as other clinical and CT features, with clinical outcome in a statistical analysis. Hemorrhages were located in putamen 20/48 (42%), thalamus 13/48 (27%), lobar 9/48 (19%), caudate 3/48 (6%), and miscellaneous locations 3/48 (6%). Outcome in putaminal hemorrhages was highly correlated with the total (P + V) and P blood volumes, whereas the V blood was less important. For thalamic hemorrhages, outcome correlated more highly with the V and P + V volumes than with the P portion. Outcome for all hemorrhages was significantly correlated, in descending order of importance, with the severity of the initial neurologic deficit, P + V blood, hydrocephalus, the number of ventricles containing blood, P, V, and blood in the 4th ventricle. In general patients with more than 20 cc of V blood did poorly. Although hydrocephalus was associated with poor outcome, ventricular drainage did not benefit 8 of 9 patients.

N2 lung cancer: outcome in patients with false-negative computed tomographic scans of the chest.

Over the past 13 years 681 consecutive patients have undergone computed tomographic staging and surgical staging of the mediastinum. Five hundred one tested negative for mediastinal lymph node enlargement by computed tomographic staging, and 37 of these patients had cancerous mediastinal lymph nodes at thoracotomy (n = 36) or mediastinoscopy (n = 1). The survival in this group of patients was analyzed according to T status, central or peripheral location of tumor, cell type, areas of mediastinum that are involved, and extent of nodal involvement with tumor. Twelve patients had central tumors, and 25 had peripheral tumors. Two of the patients in the central tumor group died postoperatively and only 2 others survived, whereas 12 of the 25 patients in the peripheral tumor group survived. Four of the 37 patients, 2 in each group, did not undergo resection, and all died. All but 2 of the 31 survivors who underwent resection received postoperative adjuvant x-ray therapy (23 patients), chemotherapy (1 patient), or x-ray therapy and chemotherapy (5 patients). The projected 2-year and 5-year survivals (Kaplan-Meier) were 40% and 28% for patients overall, 46% and 31% for those whose tumors were resected, 40% and 20% for those with resected central tumors, and 52% and 45% for those with resected peripheral tumors. None of these differences was significant. Cell type, location or number of locations of involved nodes, and the average percentage or maximum percentage of mediastinal node that was involved with tumor did not influence survival. The high negative predictive index for computed tomographic staging of the mediastinal lymph nodes and the observed 2-year and 5-year survivals in patients with false-negative computed tomographic scans of the chest justifies definitive thoracotomy without mediastinoscopy in most patients with a normal mediastinum on computed tomographic scan.

Hemodynamic correlates of outcome in patients undergoing orthotopic liver transplantation. Evidence for early postoperative myocardial depression.

OBJECTIVE: To describe the hemodynamic and oxygen transport patterns in survivors and nonsurvivors following liver transplantation (LT) and to assess their relationship to organ failure and mortality. DESIGN: Retrospective cohort. SETTING: Surgical ICU in a tertiary care university teaching hospital. PATIENTS: Consecutive series of 113 adults undergoing LT between 1984 and 1992. Patients were excluded if they died intraoperatively (n = 2), required retransplantation (n = 8), or their records were incomplete (n = 7). MEASUREMENTS AND MAIN RESULTS: Preoperative severity of illness was assessed by the acute physiology and chronic health evaluation (APACHE) II scoring system. Hemodynamic and oxygen transport variables were recorded immediately preoperatively and sequentially every 12 h during the first 2 postoperative days. Organ failures (pulmonary, renal, cardiovascular, hepatic, and central nervous system) were assessed for patients in the postoperative period. Patients were grouped as survivors (n = 82) or nonsurvivors (n = 14) with a mortality rate of 15%. Preoperative APACHE II scores were significantly lower in survivors compared with nonsurvivors (7 +/- 0 vs 11 +/- 2; p = 0.029). Both preoperatively and postoperatively, survivors sustained a relatively higher mean arterial pressure, stroke volume index, left ventricular stroke work index, cardiac index, and oxygen delivery as compared with nonsurvivors (p < 0.01). The postoperative decline in systemic blood flow that was seen in both groups was particularly prominent in nonsurvivors during the first 12 h following LT (p < 0.03). Nonsurvivors sustained an approximately fivefold increase in the rate of organ failure (p < 0.0001); all patients (n = 6) with 4 or more organ failures died. CONCLUSION: Nonsurvivors of LT have less cardiac reserve pretransplant; postoperatively, they demonstrate early myocardial depression and subsequently lower levels of cardiac index and oxygen delivery. Patients who develop these hemodynamic patterns are more prone to organ failure and death.