[Lactose malabsorption diagnosis with H2 breath test]. / Medida do H2 expirado no diagnóstico da má absorção de lactose.

One hundred and five healthy subjects under investigation for lactose malabsorption were enrolled in this prospective study. After an overnight fast, breath was collected immediately before and every 15 minutes for three hours after an oral administration of 50 g lactose dissolved in 200 mL of water (lactose overload). Blood samples were also collected before and 20, 40 and 60 minutes after the lactose overload for blood glucose determination. Expired H2 was measured by gas chromatography using a Quintron Microlyser and the maximum increase in H2 (delta-H2) was calculated. The area under the curve (ASC-H2) was also calculated using the trapezoid model. Lactose malabsorption was defined as a maximum increase in blood glucose (delta-G) under 18 mg%. The sensibility (S), specificity (E) and accuracy (A) of the H2 determination was analyzed using (a) linear regression [log (ASC-H2) = 4.034-0.029. delta-G], (b) receiver operating curve (ROC) and by (c) Q-Q plot of the cubit root transformation of the ASC-H2 values. Our results demonstrate that ASC-H2, but not delta-H2, correlates with delta-G, suggesting that the measurement of maximum increase in H2 expired following a lactose overload is not reliable for the diagnosis of lactose malabsorption. The cutoff value for the ASC-H2 using linear regression was 3260 (S = 89.3%, E = 80% and A = 86.7%), while using ROC it was 3353 (S = 88.0%, E = 80.0% and A = 85.7%) and while using Q-Q plot method it was 2936 (S = 92.0%, E = 80.0% and A = 88.6%). When the cutoff value was set to 3000, the sensibility, specificity and accuracy were 90.7%, 80.0% and 88.6%, respectively. We conclude that the calculation of the ASC-H2, but not delta-H2, following a lactose overload is reliable in detecting lactose malabsorption and can be used in the clinical practice.

[Absorption of medium chain triglycerides in patients with blind loop syndrome]. / Absorção de triglicérides de cadeia média em pacientes com síndrome de alça estagnada.

Absorption of medium chain triglycerides (MCT) was estimated in 10 patients with stagnant loop syndrome (SLS). Six patients had steatorrhea due to gastrojejunal anastomosis and 4 due to diabetic neuropathy. The diagnosis of SLS was confirmed by antibiotic therapeutic test after exclusion of other causes of malabsorption syndrome. Each patient was submitted to 2 types of diet during one week each, differing only in the type of added lipid. In the diet with long chain triglycerides (LCT), soy oil and butter were added. In the diet, with medium chain triglycerides, only MCT oil from babaçu was added. The excretion of lipid was determined in the feces in the last 3 days of each diet. The results showed that the medium fecal lipid excretion was 48.6 (sd = 19.8) g/d in the LCT diet and 26.6 (sd = 13.8) g/d in the MCT [d = 22.0; s(d) = 3.10; t = 7.10; p less than 0.001], which indicates that in patients with SLS, MCT diet was better absorbed than LCT diet. It is suggested that MCT oil may be used as a caloric source during nutritional recovery in SLS.

[Isoniazid acetylation in Gilbert's syndrome]. / A acetilação da isoniazida na síndrome de Gilbert.

Phenotyping of isoniazid acetylators in 19 Caucasoid patients with Gilbert's syndrome was achieved by evaluating the percentual of acetylisoniazid in the urine. The proportion of slow acetylators among the patients with Gilbert's syndrome was similar to those found among Caucasoids of control group. The conclusion was that Gilbert's syndrome doesn't interfere in the hepatic capacity of isoniazid acetylation.

Intestinal lymphangiectasia in systemic lupus erythematosus.

The case of a woman with SLE and protein-losing enteropathy secondary to intestinal lymphangiectasia is described. Corticosteroid therapy improved all clinical symptoms, laboratorial findings and intestinal histological alterations.

Primary neurilemmal tumour of the liver: case report.

A probably unique case of primary benign neurilemmoma of the liver is presented in which no evidence of visceral neurofibromatosis was observed. The histological characteristic of the tumour are discussed.