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PubMed1992

Malabsorption of different lactose loads in children with human immunodeficiency virus infection.

Thirty children infected with human immunodeficiency virus (HIV) (18 P1 and 12 P2, according to the classification system of the Centers for Disease Control) and 54 noninfected children were evaluated for lactose malabsorption with use of the hydrogen breath test after different lactose loads. Lactose malabsorption after load of 2 g/kg occurred in 75% of P2, 67% of P1, and in 46% of noninfected children. With a lower lactose load (1 g/kg), the prevalence of malabsorption was significantly higher among P2 children than P1 and noninfected cases. A similar figure was obtained after the lowest load (0.5 g/kg). Infected children with lactose malabsorption were significantly younger than noninfected malabsorbers (mean age +/- SD; 50.3 +/- 22 vs. 63.5 +/- 20.9 months) when the load of 2 g/kg was used. The use of lower lactose loads seems to be helpful in finding the dose that can be tolerated. This finding could have nutritional importance and could lead to better dietary management.

Breath Tests↗
PubMed1969

Evaluation of media for differentiating nonfermenting gram-negative bacteria of medical significance.

An evaluation was made of media and tests used for differentiating nonfermenting gram-negative bacteria encountered in medical bacteriology in order to determine those diagnostic procedures most useful in identifying these bacteria. The organisms examined included Alcaligenes faecalis, A. odorans var. viridans, Moraxella duplex (Mima polymorpha var. oxidans), Acinetobacter anitratum (Herellea vaginicola), A. lwoffi (Mima polymorpha), Pseudomonas fluorescens, P. putida, P. maltophilia, P. pseudomallei, P. stutzeri, P. alcaligenes, and atypical strains of P. aeruginosa. The media and tests evaluated included Sellers' medium; Hugh and Leifson's OF medium; acid production from 10% lactose infusion agar; gluconate oxidation; starch, aesculin, and Tween 80 hydrolysis; lysine decarboxylase, arginine dihydrolase, deoxyribonuclease, and tyrosinase activity; tolerance to triphenyl tetrazolium chloride, cetrimide, cadmium sulfate, 2.5% and 6.5% sodium chloride, and pH 5.6; utilization of glucose, acetamide, and malonate.

Alcaligenes↗
PubMed1980

A scheme for the identification of clinical isolates of Gram-negative anaerobic bacilli by conventional bacteriological tests.

More than 1000 strains of gram-negative anaerobic bacilli, including reference strains, clinical isolates, and members of the normal flora of the mouth, lower gastro-intestinal tract and vagina of healthy human subjects, were studied by conventional bacteriological methods and by gas-liquid chromatographic analysis of metabolic products in a series of investigations. A short combined set of tests with particular discriminant value was selected, and a scheme for the identification of the species and subspecies encountered in the diagnostic bacteriological laboratory was based upon our composite results. The tests are: antibiotic-disk resistance tests with neomycin 1000 micrograms, kanamycin 1000 micrograms, penicillin 2 units and rifampicin 15 micrograms per disk; tolerance tests with sodium taurocholate, Victoria blue 4R and gentian violet; and tests for pigment production, indole production, aesculin hydrolysis and the fermentation of glucose, lactose, sucrose, rhamnose, trehalose, mannitol and xylose. Gram-negative anaerobic bacilli are divided into four groups: (1) the fragilis group with nine species, which include the five subgroups previously classified as subspecies of B. fragilis; (2) the melaninogenicus-oralis group, which includes the three saccharolytic subspecies (ss.) of B. melaninogenicus--ss. melaninogenicus, ss. intermedius and ss. levii--and four non-pigmented species; (3) the asaccharolytic group, which comprises B. asaccharolyticus (formerly B. melaninogenicus ss. asaccharolyticus), B. corrodens and other non-pigmented non-saccharolytic strains, and (4) the fusobacteria.

Anti-Bacterial Agents↗
PubMed1994

Insulin resistance, hyperglycemia, and glucosuria in intensively milk-fed calves.

In intensively milk-fed calves post-prandial glucose (G) and insulin (I) concentrations, but not preprandial G concentrations, increased or failed to decrease during the growth period, compared with data from calves that were progressively weaned. This study was, therefore, designed to investigate G and I metabolism in veal calves. Euglycemic-hyperinsulinemic and hyperglycemic clamps in the unfed state demonstrated mutual responsiveness of I and G, but revealed a relative I resistance. After feed consumption, I resistance was exaggerated, as seen by decreased G clearance rates after i.v. G and I administration in fed compared with unfed calves. Milk replacer is a source of readily available lactose, fat, and protein, the intake of which, on a kilogram.75 basis, gradually increased with age. Increased substrate availability and effects of nutrients themselves were probably responsible for elevated plasma concentrations of G and I and led to I resistance. Additionally, hyperglycemia > 1.5 g/L was followed by urinary excretion of G.

Animal Feed↗
PubMed1984

Maltose absorption as an indicator of small-intestinal allograft rejection.

Maltose and lactose absorption, which require an intact brush border for breakdown and absorption as glucose, was evaluated as a function test to monitor the integrity of the small-bowel graft. Using the rat model of accessory small-bowel transplantation, absorption tests (in the form of an oral glucose tolerance test) were performed on iso- and allografts with either portal (PP-A) or caval venous drainage (PC-A). In isografts the absorption of maltose was found to be reproducible and not influenced by the type of venous drainage. This was not the case with the use of lactose which thus was not studied further. Allografts with PC-A demonstrated a reduction in their capacity for maltose absorption on the fifth postoperative day, as the glucose peak at 30 min (T30) was significantly blunted in comparison to that for isografts with PC-A (167 mg% +/- 12 vs 204 mg% +/- 8). Functional impairment preceded histologic changes which did not arise before the sixth-to-seventh postoperative day in rats with PC-A. Allografts with PP-A absorbed maltose on the fifth postoperative day nearly as effectively as did isografts (T30 min: 185 mg% +/- 14 vs 213 mg% +/- 8). By the ninth postoperative day, the serum glucose curve after maltose administration was flattened for grafts with PC-A (T30 min: 137 mg% +/- 11) which were rejected acutely (host's death) after 11.8 days +/- 0.45. A similar impairment of maltose absorption was not seen in the PP-A group (chronic graft rejection after 22.8 days +/- 1.8) until the 15th postoperative day.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption↗
PubMed1986

Leucocyte migration inhibition in cow's milk protein intolerance.

The leucocyte migration inhibition (LMI) was determined in an assay after in vitro challenge with beta-lactoglobulin. The assay was considered positive when migration inhibition index was greater than 20% (mean +3 SD of healthy infants). Ninety-eight infants with protracted diarrhoea and failure to thrive, 16 healthy, 12 malnourished, and 16 infants suffering from acute gastroenteritis were studied. Of the 98 patients with protracted diarrhoea, 12 fulfilled Goldman's criteria for cow's milk protein intolerance, 63 had lactose malabsorption, and in 15 no associated causative factor was identified. The mean index of migration inhibition in the cow's milk allergic group (58.83 +/- 11.98) was higher than in healthy controls (8.25 +/- 3.91), the difference being statistically significant (p less than 0.05). The test was positive in all patients with cow's milk protein intolerance. The assay was also positive in four other patients suffering from protracted diarrhoea, two of whom had lactose malabsorption. All the infants with acute gastroenteritis and malnutrition had values within the normal range. The migration inhibition index in five patients with cow's milk intolerance had declined to 24.74 +/- 4.87 in assays performed 1-6 weeks after return of clinical tolerance to cow's milk (p less than 0.05) but the test was still within the positive range in three of the five infants. These results suggest that this cell mediated immune assay is a sensitive test for the diagnosis of cow's milk protein intolerance in infants. The specificity needs to be reassessed in the light of more objective criteria for the diagnosis of cow's milk protein intolerance.

Animals↗
PubMed2003

Impaired insulin secretory capacity in mice lacking a functional vitamin D receptor.

It was the aim of this study to further explore the functional role of vitamin D in the endocrine pancreas. By gene targeting, we have recently generated mice in which a lacZ reporter gene is driven by the endogenous vitamin D receptor (VDR) promoter. These mice express a functionally inactive mutant VDR. Pancreatic islets but not exocrine pancreas cells showed strong lacZ reporter gene expression in mutant mice. To rule out possible influences of hypocalcemia on pancreatic endocrine function, a rescue diet enriched with calcium, phosphorus, and lactose was fed to wild-type (WT) and VDR mutant mice. The rescue diet normalized body weight and mineral homeostasis in VDR mutants. In glucose tolerance tests, baseline blood glucose levels were unchanged in fasting VDR mutants. However, blood glucose was elevated after oral or subcutaneous glucose loading, and maximum serum insulin levels were reduced by approximately 60% in VDR mutants vs. WT mice on either diet. In addition, insulin mRNA levels were decreased in VDR mutant mice on both diets, whereas pancreatic beta cell mass, islet architecture, and islet neogenesis were normal. These findings clearly establish a molecular role of the vitamin D-responsive elements in pancreatic insulin synthesis and secretion in vivo.

Animals↗
PubMed1989

Extent of lactose absorption in children with active celiac disease.

We have estimated lactose absorption indirectly by the breath H test to see if disaccharide exclusion is necessary for untreated celiac children. Lactose at 2 g/kg body weight (maximum 50 g) was administered to 42 infants and children (ranging in age from 9 months to 12 years) with flat small intestinal mucosa. Later, different amounts of lactose were given to determine the quantities tolerated and absorbed. One hundred percent of patients expired hydrogen more than 20 ppm over the baseline after an oral lactose load of 2 g/kg (maximum 50 g). Thirty-eight percent of them did not tolerate this quantity. Thirty-seven subjects aged 0-6 years absorbed and tolerated 0.5-1.5 g/kg (5-12.5 g total), and five patients aged 6-12 years absorbed and tolerated 0.5-0.6 g/kg (12-16.2 g total). We conclude that in many subjects with untreated celiac disease, lactase activity is sufficient for absorption and tolerance of the amount of lactose present in 250-300 ml cow's milk. Because of lactose's nutritional value, it should not be excluded unless necessary.

Breath Tests↗
PubMed1992

Lactose digestion from unmodified, low-fat and lactose-hydrolyzed yogurt in adult lactose-maldigesters.

The efficiency of carbohydrate absorption from two unmodified plain yogurts, a low-fat yogurt and a yogurt produced from lactose-hydrolyzed milk, was compared using the breath hydrogen response in 14 lactose-maldigesters. The maldigesters showed symptoms of intolerance to a standard 360 ml glass of milk containing 18 g lactose. Compared to intact milk, the breath hydrogen response to two varieties of unmodified yogurt and the lactose hydrolyzed yogurt was severely attenuated while the hydrogen response to low-fat yogurt was intermediate. Intolerance symptoms were significantly and equally reduced with all four yogurt products compared to milk. Ten lactose-digesters had a significantly greater efficiency of lactose digestion with 360 ml of milk than the 14 maldigesters; however, except for the magnitude of the maximum rise in breath H2, no inter-group differences were observed in response to unmodified yogurt. We conclude that lactose prehydrolysis adds nothing to the ability to tolerate and digest plain, full-fat yogurts, but it may be useful with low-fat or pasteurized varieties.

Adult↗
PubMed1998

Use of hydrophilic polymers with microcrystalline cellulose to improve extrusion-spheronization.

Microcrystalline cellulose 19 parts was combined with sodium carboxymethylcellulose, hydroxypropylmethyl cellulose, hydroxypropyl cellulose or polyvinylpyrrolidone one part, either by spray-drying or physical mixing. This combined excipient (20%) mixed with lactose (80%) and water was added to aid formation of pellets by the process of extrusion-spheronization. Spray-dry combined excipient produced pellets with higher yield, better sphericity and improved tolerance to minor variation in the level of water added, compared with the physical mix excipient. Physicochemical testing based on scanning electron microscopy with energy dispersive analysis, differential scanning calorimetry and X-ray diffraction analysis, indicated that the spray-drying with the hydrophilic polymer caused disintegration of the microcrystalline cellulose component into smaller crystallites, favouring its more uniform dispersion throughout the lactose during subsequent processing. The hydroxypropyl cellulose or polyvinylpyrrolidone containing excipients were the most satisfactory of the hydrophilic polymers examined, because they had the least adhesive strength favouring maximum yield of highly spherical pellets.

Calorimetry, Differential Scanning↗
PubMed1992

Chronic lactic acidosis in a patient with acquired immunodeficiency syndrome and mitochondrial myopathy: biochemical studies.

A 30-yr-old man with acquired immunodeficiency syndrome treated with zidovudine developed biopsy-proven mitochondrial myopathy. Chronic lactic acidosis (lactate, 10 +/- 1 mmol/L) persisted for more than 5 wk. Liver function tests were normal, but the concentration of lactose rose to 16.1 mmol/L when 500 mmol of ethanol was infused. The concentration of lactose rose by only 1.5 mmol/L with maximally tolerated exercise. If this mitochondrial lesion compromised flux through the electron transport system, increased turnover of ATP with exercise should have exacerbated the degree of lactic acidosis because of increased need to regenerate ATP via glycolysis. Two possible explanations will be discussed: first, there was both a rapid rate of production of lactic acid in affected muscles in conjunction and an equally rapid rate of removal by uninvolved organs. Second, there was a low net rate of production of lactic acid in involved muscles despite the exercise.

Acidosis, Lactic↗
PubMed1994

Lactose maldigestion and milk intolerance: a study in rural and urban Mexico using physiological doses of milk.

Lactose digestion capacity after ingestion of physiological doses of milk and its effect on milk intolerance and consumption were studied in rural and urban populations from three regions of Mexico with different milk intakes. All subjects (n = 926) received two treatments: whole milk (240 mL for children and 360 mL for adults) and the same amount of 90% lactose-hydrolyzed milk; 72% of the subjects also received as a third treatment a water solution containing lactulose (8 g for children and 10 g for adults). Lactose maldigestion determined by a hydrogen breath test was detected in 2 to 43% of subjects (depending on age group) and was higher in subjects from central and southern Mexico than in subjects from northern Mexico (P < 0.01). Only the experience of major symptoms of intolerance affected milk consumption, and these symptoms were present in 0 to 11% of children > 4 y old and in 7 to 17% of the 13- to 60-y-old subjects. No significant differences were found in lactose maldigestion or milk intolerance between rural and urban populations, but milk consumption was higher in urban areas (P < 0.01). Milk consumption in our study was affected primarily by factors not related to the capacity to digest or tolerate the lactose in milk.

Adolescent↗
PubMed1989

Lactose malabsorption in children with symptomatic Giardia lamblia infection: feasibility of yogurt supplementation.

An investigation was carried out on 61 children suffering from symptomatic giardiasis with the object of verifying the incidence and entity of lactose malabsorption. Furthermore, the possibility of a substitutive yogurt diet was verified in the lactose malabsorbers. The subjects, all children older than 1 year, were studied according to a schedule that included a lactose hydrogen breath test (BT) performed prior to therapy and a further BT 60 days following therapy. The subjects were divided in two groups: group A, 40 children, received a dose of 250 ml of cow's milk; group B, 21 children, received a stress dose of 2 g/kg lactose (max 50 g). Those subjects who were lactose malabsorbers at the 60 day follow-up were also given a BT at 75 days, and in the case of persistent malabsorption, a further BT was performed after 24 h with the administration of yogurt (450 g containing 12.1 g of lactose). Furthermore, 40 subjects matched for age and sex but without any GI complaints served as controls. The results showed lactose malabsorption to be frequent in children with Giardia lamblia symptomatic infection. According to the BT with a standard lactose load, all patients were malabsorbers; when testing lactose absorption with 250 ml of cow's milk, 45% of patients were found to be malabsorbers. In the latter subjects, the oral load of yogurt was uniformly well tolerated and gave rise to no H2 increment on the BT. We conclude that the occurrence of lactose malabsorption of nutritional relevance is common in children suffering or having suffered from giardiasis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗