Clinical trial designs based on sequential conditional probability ratio tests and reverse stochastic curtailing

We propose a group sequential method based on the sequential conditional probability ratio test and show that it has the conservatism desired in practice. We also propose calculating the discordant probability, that is, the probability that the sequential test concludes differently from a fixed-sample test at the planned end of the trial, recognizing that this probability could be substantial, even if the sequential test has the same size and power as the fixed-sample size test at the planned end of the study. In addition, we show that the proposed method can be used as a stochastic curtailing tool. Thus, the method accommodates unplanned interim analyses as well as those deemed necessary based on data trends, virtually without inflating the type I error, but it is less conservative than the usual stochastic curtailing. The method is implemented through an interactive computer program.

Random effects models in latent class analysis for evaluating accuracy of diagnostic tests

When the results of a reference (or gold standard) test are missing or not error-free, the accuracy of diagnostic tests is often assessed through latent class models with two latent classes, representing diseased or nondiseased status. Such models, however, require that conditional on the true disease status, the tests are statistically independent, an assumption often violated in practice. Consequently, the model generally fits the data poorly. In this paper, we develop a general latent class model with random effects to model the conditional dependence among multiple diagnostic tests (or readers). We also develop a graphical method for checking whether or not the conditional dependence is of concern and for identifying the pattern of the correlation. Using the random-effects model and the graphical method, a simple adequate model that is easy to interpret can be obtained. The methods are illustrated with three examples from the biometric literature. The proposed methodology is also applicable when the true disease status is indeed known and conditional dependence could well be present.

Emory Angioplasty Versus Surgery Trial (EAST): design, recruitment, and baseline description of patients

In patients with multivessel coronary artery disease who require revascularization there is uncertainty as to the selection of the appropriate patients for percutaneous transluminal coronary angioplasty (PTCA) as opposed to coronary artery bypass grafting (CABG). To define the relative roles of PTCA and CABG for multivessel disease, 392 patients were randomly assigned to revascularization by PTCA or CABG and followed for 3 years. This is a single-center randomized study in which individual group assignment was known but grouped data remained blinded until a full 3 years of follow-up was complete on all patients. The patients were randomized in 4 strata: (1) 2-vessel disease with 1 lesion per vessel; (2) 2-vessel disease with multiple lesions in at least 1 vessel; (3) 3-vessel disease with 1 lesion per vessel; and (4) 3-vessel disease with multiple lesions in at least 1 vessel. All data were collected on study-specific forms and sent to an independent biostatistical coordinating center for entry into a computerized database. All data will be analyzed by intention-to-treat. The primary endpoint of the trial is the composite of death of any cause, Q-wave myocardial infarction within 3 years, or a large reversible thallium defect at 3 years. Multiple secondary endpoints will include each of the components of the primary endpoint, the need for additional procedures, angiographic status at 1 and 3 years measured by an independent quantitative coronary arteriography laboratory, and measures of quality of life. A total of 5,118 patients were screened, of whom 3,371 were excluded for angiographic reasons, 191 because the angioplasty operators or surgeons believed that the patients were anatomically unsuitable, and 714 for clinical exclusions, leaving 842 eligible patients, of whom 392 were randomized. Of these, 40% had triple-vessel disease and 60% had double-vessel disease. There was no baseline difference between the 2 treatment arms for any clinical or major angiographic variable. This randomized trial will permit an in-depth comparison of coronary angioplasty and coronary surgery in comparable patients suitable for either procedure. Clinical, angiographic, and quality-of-life comparisons will be made and should be helpful in medical decision making between the 2 procedures.

Effect of distal splenorenal shunt on survival of patients with primary biliary cirrhosis

Distal splenorenal shunt is known to effectively control bleeding from esophageal and gastric varices; however, the effect of this selective shunt on liver function is less well understood. We examined retrospectively the effect of distal splenorenal shunt on the survival of 19 patients with primary biliary cirrhosis subjected to surgery for bleeding varices over a 20-yr period and had been followed for at least 1 yr. Actual Kaplan-Meier survival curve was compared with predicted survival curve based on the Mayo Clinic model using clinical data collected at the time of surgery. The patients median length of follow-up was 65.9 mo. Ten of the 19 patients died or underwent orthotopic liver transplantation during the period of observation. The actual Kaplan-Meier and predicted Mayo Clinic model survival curves were similar and did not differ significantly. Survival was best in patients with good liver function (i.e., low Mayo risk scores). Distal splenorenal shunt, therefore, did not appear to have an adverse effect on the survival of patients with primary biliary cirrhosis. We conclude that variceal bleeding in primary biliary cirrhosis patients with good liver function should not be considered an indication for liver transplantation. Instead, if treatment with sclerotherapy or beta-blockers fails then distal splenorenal shunt will prevent recurrent bleeding in 90% of patients and leave them with an excellent prognosis.

A randomized trial comparing coronary angioplasty with coronary bypass surgery. Emory Angioplasty versus Surgery Trial (EAST)

BACKGROUND

The clinical benefit of percutaneous transluminal coronary angioplasty (PTCA) as compared with coronary-artery bypass grafting (CABG) for patients with multivessel coronary artery disease has not been established. To determine the outcomes of these treatments in patients referred for the first time for coronary revascularization, we conducted a three-year prospective, randomized trial comparing the two procedures.

METHODS

Revascularization was performed by accepted methods. Follow-up clinical information was collected every six months, and coronary arteriography and thallium stress scanning were performed at one and three years. The primary end point was a composite of death, Q-wave myocardial infarction, and a large ischemic defect identified on thallium scanning at three years. Secondary end points included clinical and angiographic status and the need for additional revascularization procedures. Data were analyzed according to the intention-to-treat principle.

RESULTS

Of the 5118 patients screened for the trial, 842 (16.5 percent) were eligible for enrollment, and 392 (7.7 percent) agreed to participate. A total of 194 patients were randomly assigned to the CABG group, and 198 to the PTCA group. The primary end point occurred in 27.3 percent of the CABG group and 28.8 percent of the PTCA group (P = 0.81). Death occurred in 6.2 percent of the CABG group and 7.1 percent of the PTCA group (P = 0.73 by log-rank test). At three years, the proportions of patients in the CABG group who required repeated bypass surgery (1 percent) or angioplasty (13 percent) were significantly lower than the proportions in the PTCA group (22 and 41 percent, respectively; P < 0.001). Angiographic studies at three years showed a greater degree of revascularization in the CABG group. Angina was more frequent in the PTCA group (20 percent) than in the CABG group (12 percent).

CONCLUSIONS

We found that CABG and PTCA did not differ significantly with respect to the occurrence of the composite primary end point. Consequently, the selection of one procedure over the other should be guided by patients' preferences regarding the quality of life and the possible need for subsequent procedures.

Screening for cognitive impairment in older individuals. Validation study of a computer-based test

OBJECTIVE

This study examined the validity of a computer-based cognitive test that was recently designed to screen the elderly for cognitive impairment.

DESIGN

Criterion-related validity was examined by comparing test scores of impaired patients and normal control subjects. Construct-related validity was computed through correlations between computer-based subtests and related conventional neuropsychological subtests.

SETTING

University center for memory disorders.

PARTICIPANTS

Fifty-two patients with mild cognitive impairment by strict clinical criteria and 50 unimpaired, age- and education-matched control subjects. Control subjects were rigorously screened by neurological, neuropsychological, imaging, and electrophysiological criteria to identify and exclude individuals with occult abnormalities.

RESULTS

Using a cut-off total score of 126, this computer-based instrument had a sensitivity of 0.83 and a specificity of 0.96. Using a prevalence estimate of 10%, predictive values, positive and negative, were 0.70 and 0.96, respectively. Computer-based subtests correlated significantly with conventional neuropsychological tests measuring similar cognitive domains. Thirteen (17.8%) of 73 volunteers with normal medical histories were excluded from the control group, with unsuspected abnormalities on standard neuropsychological tests, electroencephalograms, or magnetic resonance imaging scans.

CONCLUSIONS

Computer-based testing is a valid screening methodology for the detection of mild cognitive impairment in the elderly, although this particular test has important limitations. Broader applications of computer-based testing will require extensive population-based validation. Future studies should recognize that normal control subjects without a history of disease who are typically used in validation studies may have a high incidence of unsuspected abnormalities on neurodiagnostic studies.

Volumetric and functional liver blood flow are both increased in the human transplanted liver

This study measured volumetric liver blood flow and galactose clearance concurrently during orthotopic liver transplant in human subjects. Ultrasound transit time flowmeters measured hepatic artery and portal vein flow 1-3 h after reperfusion. Galactose (100 mg/min) was infused over 45-60 min to steady state for calculation of clearance. Mean +/- S.D. total volumetric flow was 1966 +/- 831 ml/min with portal flow contributing 86%. Mean galactose clearance was 1988 +/- 641 ml/min. There was a significant correlation (p < 0.05, r = 0.61) between volumetric total liver blood flow and galactose clearance. The data show that: (i) the newly transplanted liver is capable of metabolizing galactose within 1-3 h of reperfusion; and (ii) liver blood flow is high in the newly implanted liver. The clinical importance of this observation is that there is increased clearance of high first pass substances by the transplanted liver which may be of importance in patient management.

Hemodynamics during liver transplantation: the interactions between cardiac output and portal venous and hepatic arterial flows

Liver blood flow and systemic hemodynamics were measured intraoperatively in 34 patients after liver transplantation. Ultrasound transit-time flow probes measured hepatic arterial and portal venous flow over 10 to 75 min 1 to 3 hr after reperfusion. Cardiac output was measured by thermodilution. Mean cardiac output was 9.5 +/- 2.8 L/min; the mean total liver blood flow of 2,091 +/- 932 ml/min was 23% +/- 11% of cardiac output. Mean portal flow of 1,808 +/- 929 ml/min was disproportionately high at 85% +/- 10% of total liver blood flow. Correlation analysis showed a significant (p less than 0.01; r = 0.42) correlation between cardiac output and portal venous flow and a trend toward negative correlation (p = 0.087) between cardiac output and hepatic arterial flow. These data show that increased flow in the newly transplanted liver is predominantly portal venous flow and is associated with high cardiac output and reduced hepatic arterial flow. In the last 13 patients studied, portal flow was reduced by 50% and the hepatic artery response was measured. We saw a significant (p less than 0.05) increase in hepatic artery flow from 322 +/- 228 to 419 +/- 271 ml/min, indicating an intact hepatic arterial buffer response. The hepatic artery response also showed that it is a reversible rather than a fixed resistance that contributes to the low hepatic artery flow in these patients.

Selective shunt in the management of variceal bleeding in the era of liver transplantation

This study reports the Emory experience with 147 distal splenorenal shunts (DSRS) and 110 orthotopic liver transplants (OLT) between January 1987 and December 1991. The purpose was to clarify which patients with variceal bleeding should be treated by DSRS versus OLT. Distal splenorenal shunts were selected for patients with adequate or good liver function. Orthotopic liver transplant was offered to patients with end-stage liver disease who fulfilled other selection criteria. The DSRS group comprised 71 Child's A, 70 Child's B, and 6 Child's C patients. The mean galactose elimination capacity for all DSRS patients was 330 +/- 98 mg/minute, which was significantly (p less than 0.01) above the galactose elimination capacity of 237 +/- 82 mg/minute in the OLT group. Survival analysis for the DSRS group showed 91% 1-year and 77% 3-year survival, which was better than the 74% 1-year and 60% 3-year survivals in the OLT group. Variceal bleeding as a major component of end-stage disease leading to OLT had significantly (p less than 0.05) poorer survival (50%) at 1 year compared with patients without variceal bleeding (80%). Hepatic function was maintained after DSRS, as measured by serum albumin and prothrombin time, but galactose elimination capacity decreased significantly (p less than 0.05) to 298 +/- 97 mg/minute. Quality of life, measured by a self-assessment questionnaire, was not significantly different in the DSRS and OLT groups. Hospital charges were significantly higher for OLT (median, $113,733) compared with DSRS ($32,674). These data support a role for selective shunt in the management of patients with variceal bleeding who require surgery and have good hepatic function. Transplantation should be reserved for patients with end-stage liver disease. A thorough evaluation, including tests of liver function, help in selection of the most appropriate therapeutic approach.

Role of sodium in mediator release from human basophils

We studied the effect of extracellular sodium concentration on histamine release (HR) from human basophils initiated by immunologic and nonimmunologic stimuli. We found that lowering extracellular sodium markedly enhances HR induced by an immunologic stimulus from these cells. In buffer in which sodium had been replaced with univalent ions of strong bases, enhancement of HR increased as extracellular sodium decreased. Enhancement was the result of increased duration of release. When sucrose was used for replacement of sodium, we also observed that enhancement of HR increased as extracellular sodium decreased, but there was some lessening of enhancement at [Na+]e between 5 and 10 mmol/L. Ouabain, which is an inhibitor of the Na+/K+ adenosine triphosphatase, and bumetanide and furosemide, which are inhibitors of Cl(-)-dependent Na(+)-K+ cotransport, caused small increases in enhancement of HR by sodium-deficient buffers; 4,4'-diisothiocyanostilbene-2-2'-disulfonic acid, an anion transport inhibitor, caused some inhibition of enhancement of HR. Analogues of amiloride, such as 5-(N-N-hexamethylene) amiloride (HMA) and 5-(N-4-chlorobenzyl)-2'-4'dimethylbenzamil (CBDMB), inhibit Na+/H+ exchange, Na+/Ca++ exchange, and Na+ channels. Interestingly, at higher doses, HMA and CBDMB caused marked enhancement of HR in both normal and sodium-deficient buffers. These results suggest that several cellular regulatory mechanisms potentially are important for normal basophil secretion. The most likely are pH regulatory mechanisms that include Na+/H+ exchange and anion exchangers that transport alkaline equivalents. Our findings enhancement of basophil HR by HMA and CBDMB is particularly noteworthy in light of the recent interest in use of amiloride by inhalation for therapy of lung disease in patients with cystic fibrosis.

Prevalence of invasive cytomegalovirus disease with administration of muromonab CD-3 in patients undergoing orthotopic liver transplantation

OBJECTIVE

To assess the association of cytomegalovirus (CMV) disease with the administration of muromonab CD-3 (OKT-3) in patients undergoing liver transplant; specifically, to assess the risk of OKT-3 use as an agent for rejection prophylaxis and as an agent for therapy of rejection.

DESIGN

Retrospective review of medical records.

STUDY POPULATION

83 liver transplant recipients (43 men, 40 women) with a mean age of 41.5 years (range 16-62).

DATA EXTRACTION

The medical record for each liver transplant recipient was reviewed and analyzed for the following variables: (1) preoperative recipient CMV serology, (2) donor CMV serology, (3) incidence of invasive CMV disease, (4) administration of OKT-3, (5) postoperative administration time of OKT-3, and (6) the relationship between the administration of OKT-3 and the prevalence of invasive CMV disease.

RESULTS

OKT-3 was administered to 34 of 83 (40.9 percent) liver remainder received OKT-3 as rejection rescue. All patients received OKT-3 5 mg iv for 14 days. Seventeen of the 34 patients receiving OKT-3 (50 percent) developed invasive CMV disease; 58.8 percent of the patients (20/34) receiving OKT-3 were given the agent within the first 14 postoperative days. Sixteen of these 20 patients (80 percent) developed invasive CMV disease. One of 14 patients (7.1 percent) who received OKT-3 after the first 14 postoperative days developed invasive CMV disease. Of those patients 94 percent (16/17) received OKT-3 in the first 14 postoperative days. This prevalence differed significantly from those receiving OKT-3 after the 14th postoperative day and those who did not receive OKT-3 at any time during their hospital course.

CONCLUSIONS

The patients who received early administration of OKT-3 in our study had a greater risk of invasive CMV disease than did those who received OKT-3 later in the hospital course.

High cardiac output of advanced liver disease persists after orthotopic liver transplantation

This study measured cardiac output before and 1 or 2 yr after orthotopic liver transplantation in 23 patients. Cardiac output was measured by thermodilution before transplantation and by first-pass radionuclide angiocardiography at follow-up. Study patients were selected as those doing well clinically and by standard laboratory tests at 1-yr and 2-yr reevaluations with no evidence of rejection: six had mild recurrent hepatitis shown on biopsy samples. Hepatocyte function was normal at the time of the study as shown by galactose elimination capacity of 442 +/- 90 mg/min. Medications were cyclosporine and prednisone in all patients, azathioprine in 10 patients and a combination of antihypertensive therapy to maintain diastolic blood pressure less than 90 mm Hg in 20 patients. Mean (+/- S.D.) pretransplantation cardiac output was 9.1 +/- 3.1 L/min and remained elevated at 8.3 +/- 2.1 L/min 1 yr, and 9.6 +/- 2.6 L/min (n = 13) 2 yr after transplantation. A significant (p less than 0.001) correlation was found between pretransplant and follow-up cardiac output. End diastolic, end systolic and stroke volumes are all increased in a pattern similar to that seen in end-stage cirrhosis. These data show that the high cardiac output of the hyperdynamic state of advanced liver disease persists after liver transplantation. The mechanisms and consequences of this require further study.

The effect of liver denervation on hepatic hemodynamics during hypovolemic shock in swine

This study tested the hypothesis that the denervated liver is more susceptible to hypovolemic shock than the normal liver. Fourteen swine, seven nondenervated and seven after liver denervation, were studied during hypovolemic shock to 50% of baseline blood pressure. Hepatic artery and portal vein flows were measured using transonic flow probes, and cardiac output and central venous pressure were measured using Swan-Ganz catheters. Hepatic artery flow fell equivalently in the two groups, from 132 +/- 71 to 94 +/- 17 ml/min in the nondenervated group compared with 149 +/- 56 to 91 +/- 55 ml/min in the denervated group. In contrast, portal flow in the denervated group (276 +/- 71 to 119 +/- 53 ml/min) fell significantly (p less than 0.001) more than in the nondenervated group (289 +/- 135 to 194 +/- 70 ml/min). The 58% reduction from baseline in portal flow in the denervated group compared with the 30% reduction in the nondenervated group suggests that the normal compensatory mechanism to maintain portal flow during hypovolemic shock is neurally mediated. It can be hypothesized that sensory afferent fibers might initiate a feedback to splanchnic vasodilatation in response to reduced portal flow. This study supports the hypothesis that the denervated liver is more susceptible to hypovolemic shock.

Medroxyprogesterone acetate, aggression, and sexual behavior in male cynomolgus monkeys (Macaca fascicularis)

Medroxyprogesterone acetate (MPA) is used clinically to treat male sex offenders, but there are conflicting reports about its effects on aggression. To investigate these matters in a nonhuman primate, four intact male cynomolgus monkeys were studied in a testing paradigm that involved the presence of a caged, aggression-arousing stimulus male either immediately before or during a pair-test with an ovariectomized, untreated female partner. After two 4-week periods of pretreatment baseline, males received weekly injections of 40 mg MPA either alone (two 4-week treatment periods) or in combination with testosterone replacement with sc implants (one period) and additional daily injections of 2 mg testosterone propionate (two periods). MPA was then withdrawn while testosterone replacement continued (three periods). The testing paradigm was effective in maintaining aggression, especially male-male aggression, for many months. Male-male aggression increased with MPA treatment, and increased further with testosterone replacement, whereas male-female aggression tended to change in the opposite direction. As in earlier studies, MPA decreased both plasma testosterone and male sexual activity, but restoring plasma testosterone levels in treated males failed to restore their sexual activity. MPA therefore has behavioral effects that are not mediated primarily by its suppression of circulating androgens.

Results of the Prospective Evaluation of Radial Keratotomy (PERK) Study five years after surgery. The Perk Study Group

In the Prospective Evaluation of Radial Keratotomy (PERK) Study, 793 eyes of 435 patients with 2 to 8 diopters (D) of myopia received a standardized surgery consisting of 8 incisions with a diamond-bladed knife set at 100% of the thinnest paracentral ultrasonic corneal thickness measurement and a diameter of the clear zone of 3.0 to 4.5 mm; 97 eyes (12%) received an additional 8 incisions. There were 757 eyes (95%) followed for 3 to 6.3 years. After surgery, uncorrected visual acuity was 20/40 or better in 88% of eyes. The refractive error was within 1 D of emmetropia for 64% of eyes; 19% were myopic and 17% were hyperopic by more than 1 D. Between 6 months and 5 years after surgery, 22% of the eyes had a refractive change of 1 D or more in the hyperopic direction. For 25 eyes (3%) there was a loss of 2 or more lines of best spectacle-corrected visual acuity.

Stability of refraction during four years after radial keratotomy in the prospective evaluation of radial keratotomy study

The Prospective Evaluation of Radial Keratotomy Study is a nine-center clinical trial of a standardized technique of radial keratotomy in 435 patients who had simple myopia with a preoperative refraction between -2.00 and -8.00 diopters. We studied the stability of the refractive error during four years after surgery for each of 341 eyes first operated on that had a single surgical procedure. Between baseline and two weeks after surgery, all eyes became less myopic; between two weeks and three months, 161 eyes (59%) lost 1.00 D or more of the initial effect; and between three and six months, 266 eyes (95%) had a stable refraction with less than 1.00 D change. The change from six months to four years was less than 1.00 D for 246 eyes (72%). There was 1.00 D or more decrease in surgical effect (increased minus power) for 13 eyes (4%), and 1.00 D or more increase in surgical effect (decreased minus power) for 82 eyes (24%). Eyes with larger amounts of preoperative myopia and smaller diameter of the clear zone were more likely to have an increasing effect of the surgery. The duration of this continued increasing effect of the surgery is unknown.

Model of spontaneous obesity in aging male Wistar rats

We analyzed retrospectively data from 148 chow-fed male Wistar rats killed between the age of 6 wk and 2 yr while varying in body weight from 136 to 917 g. The purpose of this study was to clarify the relationship of body weight and body lipid content with the composition and cellularity of the epididymal and retroperitoneal fat depots. A positive linear association was found between body weight and body water or fat-free dry residue, whereas total body lipid exhibited a curvilinear relationship with body weight. The weight of the epididymal pads was linearly related to body weight but not to body lipid. In contrast, retroperitoneal pad weight was exponentially related to body weight and paralleled total body lipid. A strong linear correlation was found between total body lipid and weight (r = 0.959) or depot lipid content (r = 0.967) of the retroperitoneal fat pads. In this rat model of aging and spontaneous obesity, significant regional differences exist in adipose depot composition and cellularity. A practical outcome of this study is a simple and accurate prediction of body lipid content from the gravimetric determination of the retroperitoneal fat depots.

Kinetics of system A amino acid uptake by muscle: effects of insulin and acute uremia

We found that acute renal failure (ARF) depresses maximal responsiveness to insulin of system A amino acid transport in muscle [Maroni, Karapanos, and Mitch. Am. J. Physiol. 251 (Renal Fluid Electrolyte Physiol. 20): F74-F80, 1986]. To examine mechanisms for this change, we measured the kinetics of system A in response to insulin and ARF in epitrochlearis muscle. Insulin stimulation increased the diffusion constant (KD) approximately twofold in muscles from both ARF and control rats, suggesting that insulin can modulate nonsaturable alpha-(methylamino)isobutyrate uptake. Compared with basal values, insulin did not significantly change maximal transport velocity (Vmax) in ARF or control rats; however, insulin decreased Michaelis constant (Km) by 79 and 63%, respectively. Inhibition of protein synthesis with cycloheximide did not prevent stimulation of system A by insulin. Acute uremia had no effect on nonsaturable uptake or basal system A kinetics. However, ARF produced opposing effects on insulin-stimulated system A kinetics. There was a approximately 47% decrease in Vmax, which was partially offset by a 66% reduction in Km. In summary, both insulin and ARF modulate system A kinetics by mechanisms that are independent of protein synthesis.

Endoscopic variceal sclerosis compared with distal splenorenal shunt to prevent recurrent variceal bleeding in cirrhosis. A prospective, randomized trial

STUDY OBJECTIVE

To define the roles of endoscopic variceal sclerosis and distal splenorenal shunt in the prevention of recurrent variceal bleeding in patients with cirrhosis.

DESIGN

A prospective, randomized clinical trial with crossover for those failing therapy. The median follow-up was 61 months.

SETTING

A private, tertiary-referral university hospital.

PATIENTS

Seventy-two patients fulfilling inclusion criteria were drawn from a total of 420 patients treated during a 4.5-year interval.

TREATMENTS

Endoscopic variceal sclerosis or distal splenorenal shunt.

MEASUREMENTS AND MAIN RESULTS

Survival was significantly (P = 0.02) improved in patients randomly assigned to receive sclerotherapy: 13 of these 37 (35%) patients failed sclerotherapy and required surgical rescue. A survival advantage (P = 0.01) was seen in patients with alcoholic cirrhosis who had this combined therapy; however, in patients with nonalcoholic cirrhosis, survival for those receiving sclerotherapy and surgical rescue was not significantly (P = 0.36) different from that of patients receiving distal splenorenal shunt. Control of variceal bleeding was significantly (P less than 0.001) better in the distal splenorenal shunt group (34 of 35 [97%] compared with 15 of 37 [41%] in the sclerotherapy group). Using death, uncontrolled rebleeding, or shunt thrombosis as the endpoints resulted in no significant difference between treatment groups. Hepatocyte function and portal perfusion were significantly better maintained in patients with alcoholic cirrhosis who were managed by sclerotherapy rather than shunt (P = 0.01 and P = 0.001, respectively).

CONCLUSIONS

Endoscopic sclerotherapy with surgical rescue for uncontrolled bleeding is the optimum therapy for patients with alcoholic cirrhosis and variceal bleeding. Survival is similar in nonalcoholic patients treated with either distal splenorenal shunt or endoscopic sclerotherapy, but shunting provides better control of variceal bleeding.

Choline may be an essential nutrient in malnourished patients with cirrhosis

Elemental diets designed for nutritional support in protein-calorie malnutrition are often deficient in choline, a nonessential nutrient. Previously, malnourished patients on these diets were found to be at risk of developing plasma choline deficiency. We have now estimated the prevalence of this deficiency by determining fasting plasma levels of choline among cirrhotic and noncirrhotic malnourished male subjects maintained on regular hospital mixed food or elemental parenteral and enteral formulas. Plasma choline concentrations (microM, average +/- SD) were as follows: (i) mixed foods, 11.3 +/- 4.3 for cirrhotic (n = 22) and 9.3 +/- 2.4 for noncirrhotic (n = 12) patients; (ii) parenteral formula, 5.3 +/- 1.6 for cirrhotic (n = 5) and 8.6 +/- 5.2 for noncirrhotic (n = 16) subjects; and (iii) enteral formula, 6.1 +/- 1.2 for cirrhotic (n = 5) and 11.7 +/- 1.9 for noncirrhotic (n = 4) subjects. The level for healthy normal subjects eating mixed foods was 12.0 +/- 2.2. The prevalence of plasma choline deficiency, i.e., plasma levels greater than or equal to 2 SD below the normal average, was as follows: parenteral formula, all cirrhotic and 10 of 16 noncirrhotic subjects; enteral formula, all cirrhotic and none of the noncirrhotic subjects. The reversibility of choline deficiency was examined in a longitudinal study of three phases involving 10 patients--5 with alcoholic cirrhosis (all on enteral formula); 5 noncirrhotic (1 on enteral and 4 on parenteral formula). During phase 1 (3-day equilibration period; ad libitum regular hospital diet), plasma choline levels were within the normal range for all subjects. During phase 2 (2 wk, choline depletion phase, elemental formulas), choline levels were subnormal in all cirrhotic subjects (5.1 +/- 2.0 microM) on enteral formula and all noncirrhotic patients on parenteral formula (5.9 +/- 1.3 microM). During phase 3 (2 wk, choline repletion phase, elemental formula + 6 g choline/day), the levels normalized in all patients (cirrhotic 11.4 +/- 3.1 microM and noncirrhotic 11.9 +/- 3.2 microM). Analyses of abdominal computed tomographic scans and plasma liver chemistries in the cirrhotic subjects during the three phases suggested a correlation between plasma choline deficiency and hepatic steatosis and abnormal liver enzyme levels in some patients. Therefore, choline may be an essential nutrient in malnourished cirrhotic patients and its deficiency may be associated with adverse hepatic effects.

Distal splenorenal shunt with splenopancreatic disconnection. A 4-year assessment

The aims of distal splenorenal shunt with splenopancreatic disconnection (DSRS-SPD) were to improve maintenance of portal flow and prevent siphoning of hepatotrophic factors from the pancreas, as occurs after standard DSRS. The main patient population targeted for improvement were alcoholic cirrhotics, who have poorer survival than nonalcoholic cirrhotics and greater loss of portal flow (60%) after standard DSRS. Seventy-eight patients had DSRS-SPD during the study period 1983 to 1987: thirty-two patients were Child's A, 25 were Child's B, and 21 were Child's C. The 35 patients with alcoholic cirrhosis were a significantly poorer risk group by Child's class and galactose elimination capacity (GEC) than the 39 patients with nonalcoholic cirrhosis. Four patients had portal vein thrombosis. At 4-year follow-up, portal perfusion is maintained in 84% alcoholic and 90% nonalcoholic patients, with hepatic and systemic hemodynamics showing identical patterns for both groups. Hepatic function measured by GEC was maintained in alcoholic patients (290 +/- 68 mg/min to 303 +/- 74 mg/min) and nonalcoholics patients (342 +/- 92 to 320 +/- 118 mg/min). Gastric variceal rebleeding occurred in 10 patients--4 early (less than 2 months) and 6 late (18 to 54 months), leading to operation in 4 and transhepatic embolization in 4 patients: 2 of these patients died from this complication. Survival data show an operative mortality rate of 6.4% and overall mortality rate of 30%, with no significant difference between alcoholic and nonalcoholic cirrhotics. DSRS-SPD has significantly improved maintenance of portal perfusion and survival in patients with alcoholic cirrhosis requiring selective shunt for variceal bleeding when compared to standard DSRS. In this population DSRS-SPD is the operation of choice. In patients with nonalcoholic cirrhosis, the current data have not shown DSRS-SPD to have advantage over standard DSRS.

Increased galactose clearance after liver transplantation: a measure of increased blood flow through the denervated liver?

This study measured the liver blood flow-dependent index of galactose clearance in patients after liver transplantation, to test the hypothesis that liver blood flow is increased in the denervated liver. Eight normal subjects and 16 patients 1 to 8 months after liver transplant were studied. All patients were stable with no evidence of severe rejection at the time of study. Galactose clearance was measured at steady state during continuous infusion of 75 mg per min of 5% galactose. The results show a statistically significant (p less than 0.01) higher average galactose clearance in the transplant patients (1,187 +/- 316 ml per min per m2) compared to the control group (709 +/- 121 ml per min per m2). The major limiting factor in galactose clearance at low concentrations is liver blood flow, and we interpret these data as evidence for increased blood flow in the transplanted liver. Possible mechanisms for the increased galactose clearance are (i) loss of normal vasomotor tone in the denervated liver, or (ii) persistence of abnormal systemic hemodynamics after transplantation. Elucidation of these mechanisms awaits further study.

Bedside cerebrospinal fluid glucose analysis

We studied the reliability and accuracy of a two-minute reagent strip (Chemstrip bG) and hand-held autoanalyzer (Accu-Chek IIR) for determining cerebrospinal fluid glucose. We found that both bedside methods were highly reliable (r = 0.93, Chemstrip bG: r = 0.95, Accu-Chek II) and were very accurate (89.7% and 96.6% accurate at +/- 15 and 20 mg/dL, respectively, for the Chemstrip bG: 91.7% and 95.8% accurate at +/- 15 and 20 mg/dL, respectively, for the Accu-Chek II) over a wide range of glucose values in 237 determinations. There was no significant difference between the two bedside methods. We conclude that these two methods of bedside glucose estimation are both highly reliable and accurate and could be used to quickly determine patients' cerebrospinal fluid glucose values.

Vitamin B6 repletion in cirrhosis with oral pyridoxine: failure to improve amino acid metabolism

This study evaluated the effect of daily oral pyridoxine supplementation in patients with cirrhosis. Eight subjects were treated with 25 mg of pyridoxine for 28 days. Before and after the supplementation period, B6 status was assessed by measuring fasting plasma vitamer levels and response to a 25 mg oral pyridoxine load. In addition, a 24-hr urine collection was analyzed during each load study for B6 metabolites. The data indicated that supplementation achieved repletion of peripheral B6 stores, as evidenced by: (i) a significant (p less than 0.005) rise in fasting plasma pyridoxal phosphate after supplementation (mean +/- S.D. = 56.8 +/- 30.5 nmoles per liter) as compared to initial levels (17.0 +/- 17.8 nmoles per liter); (ii) a higher (p less than 0.05) percentage excretion of the pyridoxine load as urinary 4-pyridoxic acid (31.0 +/- 9.3%) compared to the initial load (19.6 +/- 5.8%), and (iii) a postsupplementation area under the plasma concentration vs. time curve for pyridoxal phosphate (377 +/- 529 nmoles.hr per liter), which was decreased (p less than 0.005) from the presupplementation value (934 +/- 756 nmoles.hr per liter). The postsupplementation fasting plasma pyridoxal phosphate concentrations were within the normal range. The consequences of B6 repletion on amino acid metabolism were measured by oral protein loads (n = 4) or oral methionine loads (n = 4). No significant changes were observed for methionine or any other amino acid in regard to plasma fasting concentration, peak concentration or AUC. Although the vitamin B6 deficiency of cirrhosis was corrected by daily oral pyridoxine supplementation, there was apparently no improvement in the deranged amino acid metabolism.

Symmetry of refractive and visual acuity outcome in the Prospective Evaluation of Radial Keratotomy (PERK) study

In the Prospective Evaluation of Radial Keratotomy (PERK) study, the symmetry of refractive and visual acuity outcome was analyzed in 269 patients with bilateral radial keratotomy with a single operation in each eye. Patients were required to wait 1 year after surgery on the first eye before having surgery on the second eye. At 1 year after surgery on the second eye, 98% of patients had 3.00 diopters or less difference between their two eyes in the spherical equivalent of the cycloplegic refraction (100% before surgery), and 96% of patients had 3.00 D or less difference between their two eyes in the amount of refractive power in the vertical meridian (100% before surgery). Thus, surgically induced refractive anisometropia was not a major complication in the PERK study. However, 14% of patients had four to eight Snellen lines difference in the uncorrected visual acuity between their two eyes (1% before surgery), emphasizing that induced asymmetry of refraction is a potential clinical problem for some patients.

EEG mean frequencies are sensitive indices of phenylalanine effects on normal brain

We previously reported that changes in plasma phenylalanine (PHE) concentrations of 1000 microM or more adversely affected cognitive function and reduced mean frequency of the EEG power spectrum. In the present study, we characterized EEG effects of changes in plasma PHE from physiological to supraphysiological concentrations. Subjects were mentally normal children and adult volunteers with 3 different genotypes for phenylalanine hydroxylase (PHY): homozygous deficient, heterozygous, and homozygous normal. Double-blinded crossover studies were performed at equilibrium during PHE restriction and supplementation. The mean frequency of the power spectrum and the mean across a set of alpha-theta factors showed highly significant, reversible, generalized EEG slowing during PHE supplementation in subjects homozygous for PHY deficiency. Smaller but significant changes in EEG mean frequencies occurred in the heterozygous and normal subjects. Spectral profiles of EEG change were similar in both groups; the mean alpha-theta was more sensitive in the second group. Demonstration of EEG changes with PHE supplementation in normal individuals has important dietary implications.

Natural killer cells in children with malignant solid tumors. Effect of recombinant interferon-alpha and interleukin-2 on natural killer cell function against tumor cell lines

Natural killer (NK) cells and NK cell activity were determined in three groups (newly diagnosed [n = 21], on therapy [n = 21], and off therapy [n = 18]) of children with various types of malignant solid tumors and in a control group (n = 26) by means of Leu-7 and Leu-11b monoclonal antibodies and a 4-hour 51Cr-release assay, respectively. The erythroleukemia cell line K562 was used as a target cell. The newly diagnosed group included eight patients with localized disease (Stage I-II), ten with bulky but nonmetastatic disease (Stage III), and three with metastases (Stage IV). The mean percent of NK cell activity in the newly diagnosed group was significantly higher than that of the control group. Children with Stage III tumors at diagnosis had higher mean NK cell function than those with Stage I-II and Stage IV. On therapy patients had significantly fewer NK cells and lower NK cell cytotoxicity than those in the other groups studied. We also studied the following: (1) the in vitro effect of recombinant interferon-alpha (rIFN-alpha) and recombinant interleukin-2 (rIL-2) on NK cell function of peripheral blood lymphocytes (PBL) from children with solid malignancies; and (2) the susceptibility of neuroblastoma-derived (CHP-126 and SKNSH) and rhabdomyosarcoma-derived (A-204) cell lines to NK cell lysis. Both rIFN-alpha and rIL-2 enhanced NK cell activity of PBL from children with malignancies and healthy children against K562 and solid tumor cell lines. The enhancing effect or rIL-2 was greater than that of rIFN-alpha. CHP-126 and SKNSH cell lines were susceptible to NK cell lysis mediated by the PBL of children with neuroblastoma and the control group. The A-204 cell line was less sensitive than K562 to NK cell cytotoxicity. Our results suggest a potential therapeutic role for both cytokines in the treatment of malignant solid tumors of childhood.

Acquired renal cystic disease in end-stage renal disease: an autopsy study of 155 cases

Autopsy reports on 155 successive end-stage renal disease (ESRD) patients and 147 control patients without ESRD, matched for age, race and gender, were collected. Cystic transformation of the kidneys was noted in 58% of the ESRD patients and 13.6% of the control patients. There were 25 ESRD patients with renal adenoma and 3 with renal cell carcinoma. The single best predictor of cystic transformation or tumorous degeneration was patient's age. A statistically significant association between cystic transformation and gender, as well as the cause of ESRD, was also found. In contrast to previous reports we were unable to document a strong association between the incidence of either cystic transformation or tumorous degeneration with the duration of dialysis, nor did these two parameters correlate with mode of dialysis. We suggest that cystic transformation of the kidneys in ESRD is related to age and renal failure per se, is not strongly associated with duration of dialysis and is independent of mode of dialysis. Concomitant tumorous degeneration was frequent, but this was usually an incidental autopsy finding. Renal malignancy was uncommon and metastases were absent.

Endotoxin levels measured by a chromogenic assay in portal, hepatic and peripheral venous blood in patients with cirrhosis

Endotoxin concentrations were measured in the portal, hepatic and peripheral venous blood of two groups of patients with cirrhosis using a limulus-based chromogenic assay. The high sensitivity of chromogenic detection allowed measurement of endotoxin as low as 10 to 15 pg per ml, an order of magnitude greater than previously possible by gelation studies. Group 1 consisted of 56 patients with cirrhosis undergoing angiographic evaluation. In this group, there was wide variability in hepatic venous concentration [73 +/- 110 pg per ml (mean +/- S.D.)] and peripheral venous concentration [31 +/- 58 pg per ml]. However, paired t test showed peripheral venous concentration was significantly (p less than 0.001) lower than hepatic venous concentration. Neither hepatic or peripheral venous endotoxin levels correlated significantly with a variety of clinical, biochemical or radiological parameters. Group 2 consisted of 21 patients with cirrhosis undergoing shunt surgery. Endotoxin levels again showed a wide range, with portal venous concentration (142 +/- 167 pg per ml) and simultaneous peripheral venous concentration (82 +/- 150 pg per ml). Paired t test in this group showed a significant (p less than 0.001) portal to peripheral venous gradient. This study showed the feasibility of measuring endotoxin in plasma to low concentrations by a chromogenic assay technique. It supports the concept of relatively high levels of endotoxin in the portal circulation. In the presence of liver disease, systemic endotoxemia occurs, which is augmented by stressful situations.

Distal splenorenal shunt for management of variceal bleeding in patients with schistosomal hepatic fibrosis

The distal splenorenal shunt was performed in 60 patients with schistosomal hepatic fibrosis in whom no evidence of cirrhosis was documented by preoperative needle and operative wedge biopsy. No patients have been lost to follow-up with a median of 37 months (range: 17-86). The results showed low operative mortality (1.7%), high patency rate (92.5%), and low recurrent variceal hemorrhage (6.7%). Thrombosed shunts were treated either by refashioning the shunt (1 patient) or splenectomy and gastric devascularization (2 patients). Initial hyperbilirubinemia and reduction in serum albumin were found in the early postoperative period, with persistent hyperbilirubinemia in 32% of the patients. The 5-year survival was 88%, with liver disease related mortality in only three patients. Clinical encephalopathy was detected in three patients (5.1%); only one of them was incapacitated. These data showed that: selective shunt (distal splenorenal shunt, DSRS) is an effective surgical procedure in the treatment of schistosomal variceal bleeding, shunt thrombosis is rare and can possible be corrected if detected early, schistosomal patients have a better survival and a lower incidence of encephalopathy after DSRS than that reported in cirrhotics, and liver biopsy should be performed for proper assessment of the schistosomal population especially in the geographic areas where the schistosoma parasite and viral hepatitis are endemic.

Splenopancreatic disconnection. Improved selectivity of distal splenorenal shunt

Distal splenorenal shunt (DSRS) improves survival from variceal bleeding in nonalcoholic cirrhotics but not in alcoholic subjects. The metabolic response after DSRS is also different in alcoholic and nonalcoholic cirrhotics. Portal perfusion, quality of blood perfusing the liver, cardiac output, and liver blood flow do not change in nonalcoholics. In alcoholics, portal perfusion is frequently lost (60%), quality of blood perfusing the liver decreases, and cardiac output and liver blood flow increase. It is proposed that portal flow is lost in alcoholics via pancreatic and colonic collaterals after surgery. Elimination of this sump by adding complete dissection of the splenic vein and division of the splenocolic ligament to DSRS (splenopancreatic disconnection, SPD) could preserve portal perfusion, decrease shunt loss of hepatotrophic factor, and improve survival in alcoholic cirrhotics. This report compares data 1 year after surgery in two groups of cirrhotics: group I (8 nonalcoholic; 16 alcoholic) had DSRS without SPD; group II (17 nonalcoholic; 11 alcoholic) received DSRS + SPD.

METHODS

Portal perfusion grade, cardiac output (CO), liver blood flow (f), hepatic function (GEC), and hepatic volume (vol) were measured before and 1 year after surgery. Shunt loss of hepatotrophic factor was estimated by insulin response (change in plasma concentration over 10 minutes: AUC) after arginine stimulation.

RESULTS

Groups I and II were similar before surgery. Metabolically, nonalcoholics remained stable after both DSRS and DSRS + SPD. After standard DSRS, alcoholics lost portal perfusion (75%, p less than 0.05), CO, and f increased (p less than 0.05), and quality of blood perfusing the liver was decreased (GEC/f: p less than 0.05). DSRS + SPD preserved portal perfusion better (p less than 0.05) in alcoholic cirrhotics than did DSRS alone. After DSRS + SPD, the metabolic response in alcoholics resembled that of nonalcoholics. CO, f, and GEC/f remained stable. These data show: DSRS + SPD preserves postoperative portal perfusion in alcoholic cirrhotics better than DSRS alone. Metabolic response to DSRS + SPD is similar in alcoholic and nonalcoholic cirrhotics. Because portal perfusion and metabolic integrity are preserved after DSRS + SPD, its use in alcoholic cirrhotics should improve survival.

Effect of beta h-endorphin on release of insulin by rabbit pancreas in response to four secretagogues: comparison with somatostatin and epinephrine

Previous work showed beta h-endorphin inhibits glucose-stimulated secretion of insulin by rabbit pancreas slices. This study, also conducted with rabbit pancreas slices, compared the antisecretagogue actions of beta h-endorphin, somatostatin 1-14, and epinephrine versus four secretagogues, glucose, mannose, leucine and potassium chloride. All three antisecretagogues inhibited all four secretagogues. The order of potency of the antisecretagogues varied according to secretagogue. Naloxone antagonized only beta h-endorphin among the three antisecretagogues, and phentolamine antagonized only epinephrine.

Distal splenorenal shunt versus endoscopic sclerotherapy for long-term management of variceal bleeding. Preliminary report of a prospective, randomized trial

This paper reports the preliminary results of a prospective randomized trial comparing endoscopic variceal sclerosis and distal splenorenal shunt (DSRS) in the management of patients with cirrhosis and variceal bleeding. Seventy-one patients have been entered; 36 have received sclerosis and 35 DSRS. Randomization of the study population was stratified on Child's A/B (56%) and Child's C (44%). Sixty-one per cent had alcoholic and 39% non-alcoholic cirrhosis. No patients have been lost to follow-up, which currently stands at a median of 26 months. Rebleeding occurred significantly (p less than 0.05) more frequently in patients in the sclerosis group (19 of 36: 53%) compared to DSRS (1 of 35: 3%), but only 11 of 36 (31%) were not controlled by further sclerosis and failed that therapy. Patients in whom sclerosis failed underwent surgery. Survival was significantly (p less than 0.01) improved in the sclerosis group (+ surgery in 31%), with an 84% 2-year survival compared to a 59% 2-year survival in the DSRS group. Portal perfusion was significantly (p less than 0.05) better maintained in the sclerosis (95%) compared to the DSRS (53%) group. Galactose elimination capacity improved significantly (p less than 0.05) in 21 patients successfully managed by sclerosis at 1 year and was significantly (p less than 0.01) better maintained in the sclerosis compared to DSRS group. The authors conclude that endoscopic sclerosis: has a higher rebleeding rate than DSRS, with one third of patients failing therapy from rebleeding; allows significant improvement in liver function when successful; and gives significantly improved survival in the management of variceal bleeding when backed up by surgical therapy for patients with uncontrolled rebleeding.

The fasting B6 vitamer profile and response to a pyridoxine load in normal and cirrhotic subjects

This study established the fasting plasma and urine profiles of vitamin B6 in cirrhotics and assessed the response to an oral dose of pyridoxine. High-performance liquid chromatography was used to measure all vitameric coenzymatic and degradatory forms. In 31 patients with cirrhosis and 15 healthy controls, fasting plasma and 24-hr urine collection showed: plasma pyridoxal-5'-phosphate, the biologically active form, was significantly (p less than 0.001) reduced in cirrhotics (mean +/- S.D.: 5.7 +/- 3.2 ng per ml) compared to normals (14.2 +/- 7.5 ng per ml); plasma pyridoxal was detected in more cirrhotics (48%) than normals (28%); pyridoxic acid, the end catabolite, was significantly (p less than 0.05) lower in plasma of cirrhotics compared to normals, but 24-hr urine excretion was not different. Administration of 25 mg of pyridoxine to 7 cirrhotics and 5 normals showed the following plasma changes: pyridoxine rapidly peaked at 30 min and was totally cleared from plasma by 3 hr; plasma pyridoxal and pyridoxic acid increased in parallel up to 40-fold over baseline by 1 to 2 hr and rapidly fell toward baseline by 8 hr, and plasma pyridoxal-5'-phosphate, in contrast, increased significantly (p less than 0.05) from baseline by 60 min and was maintained above normal for 24 hr. The area under the plasma concentration vs. time curve (AUC) for pyridoxal-5'-phosphate was significantly (p less than 0.05) less for the cirrhotics than normals and showed a significant negative correlation to hepatocyte function and blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)

End-stage renal disease treatment modality and patients' quality of life. Longitudinal assessment

Quality of life assessments were obtained at two 18-month follow-up intervals from 97 end-stage renal disease patients. Data were compared for three stable treatment groups (transplant, home hemodialysis, in-center hemodialysis) and for two transfer treatment groups (hemodialysis to transplant, hemodialysis to continuous ambulatory peritoneal dialysis). Home hemodialysis patients demonstrated the highest quality of life and lowest hospitalization rates over time. Transplant patients had higher employment and perceived health status but not necessarily higher subjective quality of life as compared to in-center hemodialysis patients, and transplant patients experienced more hospitalization. At follow-up, hemodialysis patients who obtained transplants assessed their quality of life as higher than did hemodialysis patients who went on continuous ambulatory peritoneal dialysis.

Sequential quantitative EEG analysis in acute lymphocytic leukemia of children

Potential brain toxicity is a major concern in the treatment of acute lymphocytic leukemia with cranial irradiation or intrathecal methotrexate. We used quantitative EEG analysis based on the Fourier transform to study 13 children at the time of diagnosis, after induction, and following consolidation which included extended intrathecal chemotherapy. None had detectable CNS infiltration by leukemia. Nonetheless, initial EEG frequencies were markedly depressed compared to expected values for age (p less than .001), and improved dramatically after induction (p less than .001). Following consolidation, EEG frequencies remained significantly lower than predicted from a control population (p less than .05). Quantitative EEG is a sensitive procedure that appears useful in assessing subtle neurologic effects of acute leukemia and its treatment.

Plasma concentrations of transsulfuration pathway products during nasoenteral and intravenous hyperalimentation of malnourished patients

We have monitored the plasma concentrations of products of the transsulfuration pathway in 11 undernourished noncirrhotic patients, and in 10 cachectic cirrhotic subjects, before and during nasoenteral nutrition with Vivonex (Norwich-Eaton Pharmaceuticals, Norwich, NY) or total parenteral nutrition (TPN) with FreAmine III (American McGaw, Irvine, CA). In the cirrhotic cases eating a mixed diet, levels of taurine, cysteine, plasma glutathione, and free choline were subnormal. During nasoenteral hyperalimentation, methionine was elevated while cysteine, glutathione, and free choline levels remained depressed. During TPN, levels of taurine, cysteine, protein-bound cysteine, glutathione, free choline, and phosphatidyl choline were depressed and methionine was elevated. In the noncirrhotic cases eating a mixed diet, only the free choline concentration was low. During nasoenteral hyperalimentation, the plasma levels of both free choline and total carnitine were depressed. During TPN, plasma levels of cystine, protein-bound cysteine, total carnitine, free choline, and phosphatidyl choline were subnormal. These data suggest that biosynthesis of several products of the transsulfuration pathway may be inadequate in both cirrhotic and noncirrhotic patients during TPN with FreAmine III.

The short child with subnormal plasma somatomedin C

In 59 male and 59 female healthy children of average stature between 7 and 10 yr old, the normal range of plasma somatomedin C was investigated. The 95% tolerance limits narrowed progressively when the child's plasma somatomedin C status was described by the mean of one, two, three, or four determinations at 6-wk intervals. The 95% tolerance limits were therefore based on the mean of four determinations. In 97 children, age 7 to 10, below the 3.0 percentile in height, 44 had an average plasma somatomedin C below the 2.5 percentile. Among these hyposomatomedinemic short children, 19 were partially or totally deficient in growth hormone, 20 had normal immunoreactive growth hormone responses to dopa, glucagon, and sleep (nongrowth hormone deficient), and five had borderline provocative tests. Both growth hormone deficient and nongrowth hormone deficient children showed significant linear growth responses to 6-month courses of human growth hormone (0.16 to 0.70 unit/kg/wk). The responses of the latter group were 50 to 90% as great as those of the former.

Heterogeneity of growth hormone in the nocturnal serum of children

The nocturnal serum of 13 nongrowth hormone deficient, hyposomatomedinemic short children and of 12 normal children of average height was analyzed by both polyclonal and biclonal radioimmunoassays. The biclonal/polyclonal ratio for immunochemical grade human growth hormone was 1.0, but for the nocturnal sera in both groups, this ratio was significantly less than 1.0 (range 0.5-1.2, average 0.7-0.8). The ratio did not differ significantly between the two groups of children.

In vivo measurement of leucine metabolism with stable isotopes in normal subjects and in those with cirrhosis fed conventional and branched-chain amino acid-enriched diets

Low plasma levels of branched-chain amino acids, leucine, isoleucine, and valine are postulated to play an etiologic role in hepatic encephalopathy. Supplementation is advocated to reverse encephalopathy and improve nutritional status and survival. We measured in vivo leucine metabolism in normal individuals (n = 5) and in two groups of patients with cirrhosis (n = 8) with a primed continuous infusion of L-[15N, 1-13C] leucine to quantitate the following parameters of leucine metabolism: nitrogen and carbon fluxes, oxidation, contribution to protein synthesis, breakdown of endogenous protein to leucine, deamination and reamination to/from ketoisocaproate. Studies were performed in the fasting and fed states with a conventional enteral diet (Propac) and a branched chain-enriched diet (one third Propac plus two thirds Hepatic-Aid). In vivo leucine metabolism was similar in the fasting and fed states in normal individuals in patients with cirrhosis and with both diets when studied at a protein intake of 0.6 gm/kg ideal body weight/day. When fed these diets, oxidation increased (p less than 0.05) and breakdown decreased (p less than 0.05). The Hepatic-Aid diet increased (p less than 0.05) nitrogen and carbon fluxes significantly more than did the standard diet. Four additional patients with cirrhosis on a diet with more protein were studied (0.75 gm/kg ideal body weight/day). Carbon and nitrogen fluxes, oxidation, synthesis, and deamination were increased (p less than 0.05) when patients with cirrhosis were fed the Propac diet compared with those who fasted. The Hepatic-Aid diet further increased (p less than 0.05) all parameters except synthesis and did not decrease protein breakdown. These data show that patients with cirrhosis metabolize leucine in vivo in a manner identical to that of normal subjects and that leucine-enriched formulas increase oxidation to CO2 without improving protein synthesis.