Comparison of three methods for the estimation of total nitrogen losses in hospitalized patients

Since the measurement of total nitrogen output (TNO) is not routinely determined in the clinical setting, its level is frequently estimated using formulas based on the urinary urea nitrogen excretion (UUN). We measured TNO in 124 surgical patients over 990 days (TNO, 19.22 +/- 8.72 g N/day; total urinary nitrogen (TUN) 18.17 +/- 8.70 g N/day; UUN, 15.17 +/- 7.70 g N/day; mean gastrointestinal nitrogen (MGIN) 0.68 +/- 0.49 g N/day; integumental nitrogen (ITGN), 0.34 +/- 0.08 g N/day) and compared the results with the daily estimations using three different formulas: formula A, UUN + 4; formula B, UUN x 1.20 + 1.05, where 1.20 is the reciprocal of the mean ratio UUN/TUN and 1.05 the mean extraurinary nitrogen losses; and formula C, UUN x 1.0986 + 2.55, derived from the regression analysis of UUN vs TNO. TNO estimated by these formulas were 19.17 +/- 7.70, 19.26 +/- 9.24, and 19.22 +/- 8.70 g N/day, respectively. The regression analyses of the estimated TNO from the three formulas versus the measured TNO indicated that formulas A, B and C were equally accurate in estimating TNO over the entire range of UUN. However, when only values of UUN greater than or equal to 30 g N were considered, a modified formula A (UUN + 6) was the best predictor of TNO. Daily audits of the differences between the estimated and measured TNO showed comparable results for the three formulas. In 28.4 to 31.1% of the observed days the differences were higher than +/- 2 g N/day, an error which is not acceptable when estimating the protein requirements in many clinical conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

[Cholestyramine in the treatment of hypercholesterolemia. Our experience in 11 cases]

Bile acid sequestrant resins are considered agents of choice in the therapy of hypercholesterolemia non responsive to diet treatment. We evaluated the effects of cholestyramine, 12 g per day during 4 weeks, in 11 adult patients with severe hypercholesterolemia. Total cholesterol decreased from 414 +/- 112 to 302 +/- 140 mg/dl (28%), LDL cholesterol from 330 +/- 122 to 226 +/- 143 (33%) and Apo B lipoprotein from 141 +/- 31 to 115 +/- 34 mg/dl (18%), p < 0.01. HDL cholesterol including fractions HDL2 and HDL3, Apo A1 and Triglyceride levels were not modified. No significant side effects on gastrointestinal function were observed. Thus, we confirm that cholestyramine is an effective therapy for severe hypercholesterolemia.

[The effect of anti-insulin antibodies and of peptide C residual secretion on the metabolic control of diabetes type 1]

In 20 type I diabetic patients treated with conventional insulin preparations, we measured insulin antibodies and peptide C secretion. Peptide C levels 90 and 120 min after a standard breakfast correlated well with glucosylated Hb levels (r = -0.48 and -0.52, respectively). No correlation with free insulin levels was observed, in spite of a good correlation of the latter with blood glucose levels (r = -0.50 and -0.73, respectively). There was no relation between insulin antibody levels and peptide C or free insulin. Metabolic control was not affected by insulin antibodies. Insulin dose decreased in relation to the duration of the disease and reduction of body weight index and was not correlated to glycosylated Hb levels.

Influence of legume intake on biliary lipids and cholesterol saturation in young Chilean men. Identification of a dietary risk factor for cholesterol gallstone formation in a highly prevalent area

Chileans and North American Indians have one of the highest prevalence rates of cholesterol gallstones in the world. The most common theory to explain this has been the operation of some as yet undefined genetic risk factor in these populations. Searching for some common environmental factor for gallstones in Chileans and North American Indians, we found that beans and other legumes are common foods consumed by both populations. In this study we tested the hypothesis that legume intake may favor the production of biliary cholesterol supersaturation. We studied 20 young men subjected to a diet containing 120 g/day of legumes and a control diet without legumes for a period of 1 mo each. Both diets supplied identical quantities of energy, carbohydrates, protein, total fat, fiber, and cholesterol. Low-density lipoprotein cholesterol concentration decreased by 16% (p less than 0.001) after the legume diet. Biliary cholesterol saturation increased in 19 of the 20 subjects; the mean of the group markedly increased from 110% to 169% (p less than 0.001) after the legume diet. These results are consistent with the hypothesis that legume intake is a potential risk factor for cholesterol gallstone disease.

The effect of hemodialysis, vitamin D metabolites and renal transplantation on the skeletal demineralization associated with renal osteodystrophy: a computerized histomorphometric analysis

Twenty-three patients with end-stage renal failure treated by hemodialysis or transplantation were followed for up to 10 years. Sequential full thickness iliac crest bone biopsies were obtained to assess the effects on bone disease of hemodialysis, treatment with 1,25-dihydroxycholecalciferol [1,25-(OH)2D3] and 24,25-dihydroxycholecalciferol [24,25-(OH)2D3] and renal transplantation. The biopsies were analyzed by a computerized histomorphometric technique which allowed accurate measurements of calcified bone and osteoid areas. Serum aluminum and parathyroid hormone concentrations were also monitored. Hemodialysis was associated with a loss of calcified bone and an increase in osteoid areas. The progressive bone loss was arrested but not reversed following treatment with either 1,25-(OH)2D3 or 24,25-(OH)2D3. Osteoid area was unchanged or reduced following treatment with 1,25-(OH)2D3 in all but three patients who had serum aluminum concentrations in excess of 5 mumol/l. 24,25-(OH)2D3 was not effective in reducing osteoid area, and combined treatment with 1,25 and 24,25-(OH)2D3 had no effect beyond that expected with 1,25-(OH)2D3 alone. Bone biopsies showed loss of calcified bone and an increase in osteoid areas one year and more after successful renal transplantation in five patients. Nineteen of the 23 patients developed serum aluminum concentrations greater than 3 mumol/l, probably because of the use of oral aluminum hydroxide as a phosphate binding agent. In these patients serum parathyroid hormone concentrations greater than 600 pg/ml appeared to prevent the development of osteopenia.

The effect of the dihydroxylated metabolites of vitamin D and dietary phosphate restriction on bone disease in uraemic rats

Uraemic rats maintained on either a high or a low phosphate diet for 12 weeks were allocated to one of the following oral vitamin D treatment groups and received: 1,25-dihydroxycholecalciferol [1, 25-(OH)2D3], 24,25-dihydroxycholecalciferol [24,25-(OH)2D3], both 1,25-(OH)2D3 and 24,25-(OH)2D3, or no vitamin D supplements. Mean serum creatinine concentrations were elevated to a similar extent in all groups. Mean serum concentrations of calcium, phosphate and alkaline phosphatase were not significantly different from normal in any of the groups. In the group receiving the high phosphate diet and no vitamin D supplements, calcified bone area measured by quantitative computerized histomorphometry was significantly lower than in the group receiving the low phosphate diet and no vitamin D supplements (0.01 greater than P greater than 0.001), and in the groups receiving high phosphate diet and either 1,25-(OH)2D3 (0.01 greater than P greater than 0.001) or 24,25-(OH)2D3 (0.01 greater than P greater than 0.001). We conclude that uraemic rats maintained on a high phosphate diet for 12 weeks develop skeletal demineralization, this process does not occur in rats on a low phosphate diet, and a decrease in calcified bone area may be prevented by treatment with either 1,25-(OH)2D3 or 24,25-(OH)2D3.

Gastroesophageal sphincter pressure and histological changes in distal esophagus in patients with achalasia of the esophagus

A prospective study was performed in 17 patients with achalasia of the esophagus determining the manometric characteristics of the gastroesophageal sphincter, correlating it with histological analysis by biopsies taken during surgery at the distal narrowed segment of the esophagus, at the location of the sphincter. The histological findings were compared to 10 control cases. Presence or absence of ganglion cells at the Auerbach's plexuses and appearance of smooth muscle fibers were evaluated. Only one case (6%) had Chagas' disease. The mean sphincter pressure was 41 mm Hg, with incomplete relaxation in all patients. Histological analysis showed a complete disappearance of ganglion cells in 94% of the cases and a decrease in the number of neurons with marked chronic inflammatory cells in one case (6%). In all control cases, the ganglion cells were normal. Smooth muscle fibers were normal on light microscopy. No relationship was found between resting gastroesophageal sphincter pressure, length and relaxation, and histological findings at the distal esophagus. These findings suggest that the denervation in the majority of cases is located in the Auerbach plexus, with complete absence of ganglion cells and, therefore, absence of postganglionic nerve fibers.

Surgical treatment of high gastric ulcer

The purpose of this study has been to review the late results of surgical treatment of 244 patients with endoscopically proved benign chronic gastric ulcer located 5 cm or less from the cardia. In five patients, a total gastrectomy with esophagojejunostomy was performed. Proximal gastrectomy was used in 3 patients, mesogastrectomy in 5 patients, a partial Schoemaker's procedure in 73 patients, Pauchet's procedure in 70 patients, and Csendes' procedure in 23 patients. Nonresective procedures were employed in 67 patients and included the Kelling-Madlener procedure in 23 patients, pyloroplasty alone in 10 patients, gastrojejunostomy alone in 4 patients, local or wedge excision of the ulcer in 9 patients, and vagotomy and pyloroplasty in 21 patients. The follow-up evaluation was performed in 91 percent of the patients (mean 9 years postoperatively, range 5 to 15 years), with emptying endoscopy in all nonresected patients. A high mortality was observed after total or proximal gastrectomy, as well as after nonresective procedures. After the other resective techniques, low postoperative morbidity and mortality were observed. No recurrent ulcer was seen after the resective procedures. Based on these results, we propose that when the ulcer is located 5 cm below the cardia, Schoemaker's or Pauchet's procedure should be performed; if the ulcer is located 2 cm or less from the cardia, Csendes' procedure or the Kelling-Madlener procedure should be employed.

Measurement of esophageal reflux by scintigraphy

Gastroesophageal reflux and clearance of the refluxed material can be measured by plotting a time-activity curve from an esophageal area of interest after 1 mCi of 99mTc sulfur colloid is placed in the stomach. Control subjects do not have peaks exceeding a value twice that of the baseline count levels. Reflux patients exceed this value, either spontaneously or after Valsalva maneuvers. This technique has a sensitivity which is greater than that of barium and equal to the sensitivity of a pH probe in patients with both moderate and severe reflux. Scintigraphic reflux was shown in 62% of moderate refluxes and 85% of those with severe reflux as defined clinically. Clearing of the refluxed material occurs rapidly in most patients if measured by this scintigraphic technique. This test can be performed rapidly with minimal radiation exposure and is noninvasive.

The effect of the dosage of steroids on the incidence of cytomegalovirus infections in renal transplant recipients

In a retrospective survey of 92 cadaver renal transplant recipients, cytomegalovirus (CMV) infections were detected in 23 of 34 (68 per cent) patients treated with high doses of steroids but in only 27 of 58 (47 per cent) patients given low doses. Pretransplant blood transfusions were associated with both an improvement in one-year allograft survival-rates (P less than 0.05) and an increase in the incidence of CMV infections. When standardised for any transfusion effect, the incidence of CMV infections was significantly higher in those patients given high doses of steroids (P less than 0.05). In the same group of patients, moreover, CMV infections were associated with a statistically significant increase in the renal allograft survival-rate (P = 0.03).

Does surgery correct esophageal motor dysfunction in gastroesophageal reflux

The high incidence of dysphagia in patients with symptomatic gastroesophageal reflux (GER) but no evidence of peptic stricture suggests esophageal motor dysfunction. Conventional methods for detecting dysfunction (radiologic and manometric examinations) often fail to detect abnormality in these patients. Radionuclide transit (RT), a new method for detecting esophageal motor dysfunction, was used to prospectively assess function in 29 patients with symptomatic GER uncomplicated by stricture before and three months after antireflux surgery (HILL). The preoperative incidence of dysphagia and esophageal dysfunction was 73% and 52%, respectively. During operation (Hill repair), intraoperative measurement of the lower esophageal sphincter pressure was performed and the LESP raised to levels between 45 and 55 mmHg. The preoperative lower esophageal sphincter pressure was raised from a mean of 8.6 mmHg, to mean of 18.5 mmHg after operation. No patient has free reflux after operation. Postoperative studies on 20 patients demonstrated persistence of all preoperative esophageal dysfunction despite loss of dysphagia. RT has demonstrated a disorder of esophageal motor function in 52% of patients with symptomatic GER that may be responsible for impaired esophageal clearance. This abnormality is not contraindication to surgery. The results indicate that construction of an effective barrier to reflex corrects symptoms of reflux, even in the presence of impaired esophageal transit. Radionuclide transit is a safe noninvasive test for assessment of esophageal function.

A prospective randomized study comparing forceful dilatation and esophagomyotomy in patients with achalasia of the esophagus

A prospective and randomized study was performed comparing pneumatic forceful dilatation and surgical esophagomyotomy as primary treatment of patients with achalasia of the esophagus. Eighteen dilated and 20 operated patients were studied before and after treatment with 1 patient lost. Clinical, radiologic, and manometric evaluations were performed before and after treatment and acid reflux test in the late follow-up period. Immediately after treatment, a significant improvement was seen clinically, by radiologic studies and after manometric evaluation. In the late follow-up period, operated patients showed a permanent improvement in all of them, but dilated patients remained a symptomatic in about 50% of the cases. The rest had to be redilated or reoperated on due to a failure of primary dilatation leading to final good or excellent results in 60% and failure in 40% of patients. Acid reflux test showed a positive test in 31% of the operated patients and in 7% of the dilated patients. This controlled study suggests that surgical treatment of achalasia, used as primary treatment, is accompanied by significantly better long-term results compared with pneumatic dilatation according to the technique utilized by us.

A prospective randomized study comparing forceful dilatation and esophagomyotomy in patients with achalasia of the esophagus

A prospective and randomized study was performed comparing pneumatic forceful dilatation and surgical esophagomyotomy as primary treatment of patients with achalasia of the esophagus. Eighteen dilated and 20 operated patients were studied before and after treatment with 1 patient lost. Clinical, radiologic, and manometric evaluations were performed before and after treatment and acid reflux test in the late follow-up period. Immediately after treatment, a significant improvement was seen clinically, by radiologic studies and after manometric evaluation. In the late follow-up period, operated patients showed a permanent improvement in all of them, but dilated patients remained a symptomatic in about 50% of the cases. The rest had to be redilated or reoperated on due to a failure of primary dilatation leading to final good or excellent results in 60% and failure in 40% of patients. Acid reflux test showed a positive test in 31% of the operated patients and in 7% of the dilated patients. This controlled study suggests that surgical treatment of achalasia, used as primary treatment, is accompanied by significantly better long-term results compared with pneumatic dilatation according to the technique utilized by us.

Perimeter and location of the muscular gastroesophageal junction or 'cardia' in control subjects and in patients with reflux esophagitis or achalasia

The location and perimeter of the true muscular gastroesophageal junction or cardia were determined during operation in 6 patients with achalasia, in 20 control subjects, and in 40 patients with reflux esophagitis. These two latter groups were submitted to highly selective vagotomy, owing to duodenal ulcer in the control subjects and as part of the surgical technique in reflux esophagitis patients. The careful dissection and isolation of the distal 5-6 cm of the esophagus and esophagogastric junction permitted us to measure the location and perimeter very precisely. There was a very close correlation between the distance incisors-beginning of gastroesophageal sphincter measured preoperatively and the distance incisors-cardia measured during surgery. The cardia could be clearly identified by external inspection corresponding to the limit between the longitudinal muscle layer of the esophagus and the serosal surface of the stomach. The perimeter of the cardia in the patients with reflux esophagitis was significantly larger than the perimeter of the control subjects (p less than 0.001). Intraoperative manometry demonstrated that the external limit of the cardia corresponded to the beginning of the gastroesophageal sphincter. Patients with achalasia had significantly smaller perimeter than controls or reflux esophagitis patients (p less than 0.001).