Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Lactose Intolerance”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,387 records · Page 77Linked to original sources

Lysosomal sialidase deficiency in sialidosis with partial beta-galactosidase deficiency.

We analyzed the subcellular localization of sialidases in human lymphocytes from a patient with adult type sialidosis with partial beta-galactosidase deficiency and normal controls. Sialidase activities were measured with alpha,2 leads to 3 NeuAc-lactitol, 4-methylumbelliferyl-NeuAc and GM3 ganglioside as substrates. Sialidases in the lysosomes were sonication-labile and hydrolyzed mainly hydrophilic substrates such as NeuAc-lactitol and 4-methylumbelliferyl-NeuAc, but hydrolyzed subsidiarily GM3 ganglioside. On the other hand, sialidases in the plasma membrane were sonication-stable and hydrolyzed both hydrophilic substrates and GM3 ganglioside. In sialidosis with partial beta-galactosidase deficiency, the sialidases of the lysosomes showed 3-5% activity toward hydrophilic substrates and 25% activity toward GM3 ganglioside as compared with sialidase activities of the controls. However, there are no differences in the activities of the sialidases in the plasma membrane. These results demonstrate that the essential defect in this disease is the deficiency of a lysosomal sialidase.

Carbohydrate Metabolism, Inborn Errors↗

Primary prevention of insulin-dependent diabetes mellitus: simple approaches using thermal modification of milk.

Evidence is presented that new cases of primary insulin dependent diabetes mellitus (IDDM) will cease to occur when milk-processing temperatures are increased from current levels (72 degrees C) to at least 85 degrees C. This temperature is sufficient to denature bovine serum albumin (BSA), the environmental trigger molecule for IDDM. Morbidity and mortality from atherosclerotic vascular disease (ASVD) and a number of autoimmune diseases may also be reduced by such increases in milk-processing temperatures. BSA-free milk products commercially available now include those canned (> 100 degrees C), ultrapasteurized (138 degrees C), and ultrahigh-temperature (UHT) processed (149 degrees C). At less than 6400 feet elevation, BSA can be denatured by simply bringing milk to a boil (> 85 degrees C). Until such time as all milk is routinely heat-treated to denature BSA, the safest course to maintain good nutrition and prevent IDDM and other BSA-triggered diseases is selection of milk products processed at temperatures above 85 degrees C.

Animals↗

Failure of lactose-restricted diets to prevent radiation-induced diarrhea in patients undergoing whole pelvis irradiation.

Sixty-four patients were randomized prior to pelvic radiotherapy into one of three dietary groups: the control group maintained a regular diet except that they drank at least 480 cc of milk daily; the lactose-restricted group was placed on a lactose-restricted diet; and the lactase group drank at least 480 cc of milk with lactase enzyme added to hydrolyze 90% of the lactose. The patients kept records of their stool frequency and the number of diphenoxylate tablets required to control their diarrhea during a 5 week course of standard whole pelvis irradiation. The data does not support the concept that one of the mechanisms of radiation-induced diarrhea associated with pelvic irradiation is a reduction the ability of the intestine to hydrolyze ingested lactose due to the effect of the radiation on the small intestine. There was not a significant difference in stool frequency or diphenoxylate usage among the dietary groups.

Animals↗

Host to an intruder.

Explore the source record for details and available documents.

AIDS-Related Opportunistic Infections↗

Comparison of a real-time polymerase chain reaction assay for lactase genetic polymorphism with standard indirect tests for lactose maldigestion.

BACKGROUND & AIMS: There is a discrepancy in outcome between the lactose tolerance and breath hydrogen tests for lactose maldigestion. The availability of a validated genetic test for lactase polymorphism allows a reevaluation of these tests. METHODS: Thirty healthy adults participated in a 50-g lactose challenge test at a university clinic. Blood was drawn for genetic and timed blood glucose testing (2 hours), and breath hydrogen was measured (4.5 hours). Lactase genetic polymorphism was assessed by a real-time polymerase chain reaction assay. Participants completed a diet questionnaire, and symptoms were recorded during the lactose challenge. Sensitivity and specificity were calculated for each indirect test. The 2-way kappa coefficient between these tests was evaluated. Student t test and Wilcoxon rank sum test were used to compare variables. RESULTS: The lactose tolerance test as a standard had an 87.5% sensitivity and 92.7% specificity for genetic status. Only a moderate agreement between lactose tolerance test and breath hydrogen test was observed (2-way kappa coefficient, .53; 95% confidence interval, .22-.83). When genetic status was used as standard, symptoms had a moderate sensitivity and specificity. Lactose tolerance test had very good sensitivity, and the breath test had excellent specificity. CONCLUSIONS: Both indirect tests independently have good to very good sensitivities and specificities for genetic lactase status. The noted disagreement likely reflects variables that affect the tests independently of intestinal lactase status. The value of these tests in the light of the availability of genetic testing is discussed.

Adult↗

Diagnosis of irritable bowel syndrome.

Because there are no reliable biological or laboratory markers associated with the condition, the diagnosis of irritable bowel syndrome(IBS) is based on patient descriptions of common symptoms such as abdominal pain accompanied by changes in stool form or frequency and associated symptoms such as bloating and distension. With the development and refinement of symptom-based criteria for the diagnosis of IBS, the traditional need for a negative diagnostic evaluation has been questioned. This article evaluates the diagnostic characteristics of various symptom-based criteria in routine clinical practice and reviews the data regarding the yield of the multiple commonly used diagnostic tests in patients with suspected IBS.

Abdomen↗

Nutritional supplements used in weight-reduction programs increase intestinal gas in persons who malabsorb lactose.

OBJECTIVE: To determine if ingestion of 2 doses of milk-based dietary supplements produce gaseous symptoms in subjects who malabsorb lactose. DESIGN: Randomized, controlled, crossover trial. SUBJECTS/SETTING: Ten community-based subjects who malabsorb lactose. INTERVENTION: Ingestion of 2 standard servings of milk-based supplements (a powder reconstituted in fat-free milk or a ready-to-drink preparation) or low-lactose control preparations. MAIN OUTCOME MEASURES: Frequency of flatus passage and subjective impression of bloating, flatulence, and abdominal discomfort. STATISTICAL ANALYSIS: Wilcoxon signed-rank test. RESULTS: The high lactose content (27 g) of 2 servings of the powder-based supplement ingested without other food resulted in a marked increase in daily flatus passages from the basal level of 9.7+/-8.2 to 30+/-14 (mean+/-SD), and a significant increase in the subjects' perception of gas. In contrast, the lower lactose content (18.4 g) of 2 servings of a ready-to-drink supplement resulted in a flatus frequency of 17+/-10 (P=.14 vs baseline) and no significant increase in the perception of increased gas. Neither supplement resulted in a significant increase in bloating, abdominal pain, or diarrhea. The lactose content of the liquid supplement was reduced by 80% following overnight incubation with an over-the-counter lactase preparation. APPLICATIONS/CONCLUSIONS: Persons who malabsorb lactose should be aware that sizable increases in rectal gas commonly occur when milk-based powders reconstituted in milk are used as meal replacements. In contrast, gas problems probably will be minor following ingestion of 2 doses of a ready-to-drink, milk-based supplement. The lactose content of these supplements can be markedly reduced by overnight incubation with over-the-counter lactase preparations, and this manipulation should be beneficial for subjects troubled by the increased gas caused by the consumption of lactose-containing supplements.

Abdominal Pain↗

Predictors of milk consumption in a population of 17- to 35-year-old military personnel.

OBJECTIVE: The purpose of this investigation was to survey an entire population of Air Force recruits (N = 32,144) regarding milk consumption and demographic and health-related factors that may predict milk consumption. DESIGN: All subjects were required to fill out a 53-item health survey at the start of basic military training. SUBJECTS/SETTING: All recruits who entered the US Air Force from August 1995 to August 1996 participated in this study (N = 32,144). STATISTICAL ANALYSES PERFORMED: Potential correlates of milk intake were analyzed using Spearman rank order correlations and multiple linear regression. Variables were removed if they did not make a meaningful contribution to variance in milk intake. Because of skewed distributions, several variables were dichotomized (e.g., age: 17 to 24 vs 25 to 35 years). RESULTS: In terms of milk consumption, 51.7% of the respondents reported intake of fewer than 1 serving per day; only 17.9% reported intake of 3 servings or more per day. Milk intake was positively associated with body weight and fruit/vegetable intake and negatively associated with age, education level, reported milk-related gastric distress, physical activity level, dieting frequency, and concern about weight. Gender (women reported lower intake) and ethnicity (minorities reported lower intake) were independently related to milk consumption. Of all respondents, 16.1% reported themselves to have milk-related gastric distress, but rates varied depending on age, gender, and ethnicity (ranging from 10.2% for younger non-Hispanic white men to 60.4% for older Asian men). APPLICATIONS/CONCLUSIONS: Despite the efforts of large, costly campaigns designed to increase milk consumption, self-reported milk consumption in young adults is extremely low. Given the importance of dairy products as a major source of calcium in the American diet, dietetics practitioners should assess milk consumption among young adults to ensure sufficient calcium intake to maximize peak bone mass in this group.

Adolescent↗

Increased serum amylase and lipase in fructose malabsorbers.

BACKGROUND: Fructose malabsorption is frequently seen in the general population and is characterised by the inability to absorb fructose efficiently. Due to fructose malabsorption, fructose reaches the colon where it is broken down by bacteria to short fatty acids, CO(2) and H(2). Bloating, cramps, osmotic diarrhea and other symptoms of irritable bowel syndrome are the consequence. We recently found that fructose malabsorption is associated with low plasma folic acid concentrations and low serum tryptophan and zinc. Because fructose malabsorption apparently is associated not only with malabsorption of other nutrients, but also with abdominal discomfort, it was of interest to examine whether mild pancreatitis may be involved. METHODS: We retrospectively examined our data in 159 otherwise healthy adults (110 females, 49 males) aged 14-84 years (mean 45.6+/-14.4 S.D.) with gastrointestinal complaints for serum amylase and serum lipase concentrations. The patients have been tested earlier for fructose malabsorption and lactose maldigestion by measuring breath H(2) concentrations after an oral dose of 25 g fructose and 50 g lactose, respectively, 1 week apart. RESULTS: Fructose malabsorption (H(2) concentrations > or =20 ppm over baseline values) was detected in 107 of 159 individuals (67.3%). These subjects with fructose malabsorption presented with significantly higher serum amylase concentrations (73.1 U/l+/-25.7 S.D.) compared to individuals with normal fructose absorption (59.6 U/l+17.9 S.D; p=0.0009). Fructose malabsorbers also presented with higher serum lipase concentrations (122.0 U/l+/-100.3 S.D.) compared to normals (89.5 U/l+/-46.5 S.D.; p<0.05). To determine whether this finding is a consequence of any sort of malabsorption syndrome or whether it is specific for fructose malabsorption, all subjects were screened for lactose maldigestion. Lactose maldigestion (H(2) concentrations>20 ppm over baseline after lactose loading) was found in 50 of 159 individuals (31.4%). There were no significant differences in either amylase or lipase concentrations in lactose maldigestors. CONCLUSION: Serum amylase and lipase concentrations are higher in subjects with fructose malabsorption compared to normals. Therefore, fructose malabsorption should be considered as a differential diagnosis in moderately elevated serum amylase.

Adolescent↗