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Postinfectious irritable bowel syndrome.

A small but significant subgroup of patients with irritable bowel syndrome (IBS) report a sudden onset of their IBS symptoms after a bout of gastroenteritis. Population-based surveys show that although a history of neurotic and psychologic disorders, pain-related diseases, and gastroenteritis are all risk factors for developing IBS, gastroenteritis is the most potent. More toxigenic organisms increase the risk 11-fold, as does an initial illness lasting more than 3 weeks. Hypochondriasis and adverse life events double the risk for postinfective (PI)-IBS and may account for the increased proportion of women who develop this syndrome. PI-IBS is associated with modest increases in mucosal T lymphocytes and serotonin-containing enteroendocrine cells. Animal models and some preliminary human data suggest this leads to excessive serotonin release from the mucosa. Both the histologic changes and symptoms in humans may last for many years with only 40% recovering over a 6-year follow-up. Celiac disease, microscopic colitis, lactose intolerance, early stage Crohn's disease, and bile salt malabsorption should be excluded, as should colon cancer in those over the age of 45 years or in those with a positive family history. Treatment with Loperamide, low-fiber diets, and bile salt- binding therapy may help some patients. Serotonin antagonists are logical treatments but have yet to be evaluated.

Bacterial Infections↗

Breath hydrogen response to milk containing lactose in colicky and noncolicky infants.

In 122 healthy newborn infants, we studied the relationship between breath hydrogen (H2) production after feedings containing lactose (human milk or commercial formula) in colicky and noncolicky infants at 6 weeks and 3 months. Eighty-three infants (68%) developed colic (mild, moderate, or severe) by 2.6 +/- 1.8 weeks of age (mean +/- SD). Zero time (baseline) breath H2 values were significantly higher in colicky compared with noncolicky infants at both 6 weeks (40.6 +/- 41.4 vs 14.8 +/- 32.9 ppm) and 3 months (27.7 +/- 38.1 vs 8.5 +/- 18.2 ppm). There were significantly more positive breath H2 tests in colicky compared with noncolicky infants at 6 weeks (78% vs 36%) and 3 months (89% vs 45%). Failure to produce H2 throughout the breath H2 test was significantly more frequent in noncolicky compared with colicky infants at 6 weeks (50% vs 18%) and 3 months (43% vs 4%). These findings remained significant even when infants with mild colic (at 6 weeks and 3 months) were included in the noncolicky group. We conclude that colicky infants produce more breath H2 in the fasting state and in response to feedings containing lactose than noncolicky infants produce. This may represent increased lactose malabsorption, differences in colonic bacterial fermentation conditions, or differences in the handling of colonic gas produced.

Breath Tests↗

Disorders of carbohydrate digestion and absorption.

The carbohydrate malabsorptive syndromes are frequently seen by pediatricians. The congenital deficiency states are quite rare, but adult type hypolactasia and lactose intolerance following rotavirus infection are recognized with increasing frequency by primary care physicians. Therapy for these disorders involves identification of the offending carbohydrate, removal of the carbohydrate from the diet, and exclusion of other entities that may result in carbohydrate malabsorption but not respond to its removal from the diet. Prognosis for both the primary and secondary carbohydrate malabsorption syndromes is excellent. Compliance with diets for those pediatric patients who will require lifelong therapy remains problematic.

Dietary Carbohydrates↗

A cross-sectional survey of sensitization to Aspergillus oryzae-derived lactase in pharmaceutical workers.

BACKGROUND: The presence of IgE-mediated occupational respiratory sensitization to microbial enzymes has been well documented in a variety of industries. Aspergillus oryzae -derived lactase is used as a dietary aid for patients with lactose intolerance. OBJECTIVE: In 1993, a cross-sectional survey of 94 pharmaceutical workers exposed to lactase for a mean duration of 23 months and 24 nonexposed recently hired employees was initiated to identify lactase-sensitized workers and potential risk factors that could be used in making recommendations for preventing future cases of lactase sensitization. METHODS: The survey included a physician-administered questionnaire, skin prick testing to lactase enzyme and a panel of common aeroallergens, and spirometry. RESULTS: Twenty-seven of 94 lactase-exposed workers (29%) had positive skin test responses to lactase. These workers were 9 times more likely to have upper or lower respiratory symptoms compared with workers with negative skin test responses. Atopic workers were 4 times more likely to have lactase skin sensitivity than nonatopic workers. However, atopy was not a risk factor for the development of upper and/or lower respiratory symptoms. Lactase skin reactivity was not observed in the 24 nonexposed employees. CONCLUSION: This cross-sectional survey revealed that atopic workers were more likely to have lactase sensitization and that lactase-sensitized workers were more likely to have upper and/or lower respiratory symptoms, but atopy was not a risk factor for upper or lower respiratory symptoms. In spite of these findings, the company allowed only nonatopic, nonlactase-sensitized workers to continue working in high lactase-exposure areas with careful symptom monitoring and use of protective clothing. Although this strategy was successful in total prevention of new cases of occupational respiratory disease after 5 years, the results of this cross-sectional survey do not support exclusion of atopic workers from working with industrial enzymes.

Aspergillus oryzae↗

Constipation, diarrhea, and irritable bowel syndrome.

Constipation, diarrhea, and irritable bowel syndrome are commonly encountered in the primary care practice. Most episodes of constipation and diarrhea are benign and self-limited. Patients with chronic constipation should undergo a screening evaluation to exclude organic disease, after which most can be managed successfully with dietary modification and fiber supplementation. The cause of chronic diarrhea usually can be discerned clinically, with irritable bowel syndrome, inflammatory bowel disease, and lactose intolerance being diagnosed most frequently. Irritable bowel syndrome is a functional gastrointestinal disorder characterized by abdominal pain and disordered defecation, which is successfully managed with a strong physician-patient relationship and periodic pharmacologic intervention.

Chronic Disease↗

Breath hydrogen as a diagnostic method for hypolactasia.

Breath hydrogen (H2), collected by end-expiratory sampling, was measured in twenty-five patients with abdominal symptoms or diarrhoea after ingesting 50 g. of lactose. This was compared with established tests of hypolactasia. Fifteen patients with a blood-glucose rise of more than 20 mg. per 100 ml. had less than 4 parts per million (p.p.m.) rise in breath H2 at 2 hours. In contrast, ten patients with blood-glucose rises of less than 20 mg. per 100 ml. had more than a 20 p.p.m. H2 rise (mean 85.8 p.p.m. plus or minus s.d. 44.3) at 2 hours. Similarly, two patients with normal jejunal lactase activity had no significant H2 production, whereas six patients with hypolactasia had more than a 20 p.p.m. rise in H2. Symptoms related to milk or lactose ingestion were found to be unreliable. End-expiratory sampling of breath H2 would seem to be a simple, non-invasive, and accurate method of diagnosing hypolactasia, which is also very acceptable to patients. This should make it a valuable tool both in diagnostic gastroenterology and in epidemiological surveys.

Biopsy↗

Is lactase the receptor and uncoating enzyme for infantile enteritis (rota) viruses?

Rotaviruses are now regarded as important causes of diarrhoea in man, cattle, pigs, mice, and possibly other animals. Characteristically, disease occurs in newborn and young animals, and infection seems limited to the differentiated gut epithelial cells. The major surface polypeptide of the calf scours rotavirus is glycosylated, and highly purified beta-galactosidase (lactase) interacts with the virus in vitro causing removal of the outer shell of the capsid (uncoating). It is suggested that lactase present in the brush border of the intestinal epithelial cell performs a similar function in vivo by acting as a combined receptor and uncoating enzyme for the rotavirus. This hypothesis is consistent with the observations that rotaviruses seem to infect only gut epithelial cells, and that infant animals, whose lactase concentrations are generally higher than those of adult animals, seem more susceptible to rotavirus infections. Implications of the hypothesis include possible new approaches to laboratory cultivation of rotaviruses, which should be more successful in cells selected for surface lactase activity, and the suggestion that the epidemiology of human rotavirus infections may be influenced by the fact that different ethnic groups have different lactase levels (and hence lactose intolerance) in adulthood.

Acute Disease↗

High colonic pH promotes colorectal cancer.

Considerable evidence suggests that the carcinogens or co-carcinogens responsible for the development of colorectal cancer are either bacterially degraded bile acids or cholesterol. It is proposed that a high colonic pH promotes co-carcinogen formation from these substances and that acidification of the colon either by dietary fibre (following its bacterial digestion to short-chain fatty acids) or milk (in lactose-intolerant individuals) may prevent this process.

Bacteria↗

Evaluation of milk and nutrient intakes of school children in Nigeria.

The study was conducted to evaluate the contribution made by school milk to the nutrient intake of 246 primary school children in urban and rural areas of Anambra State, Nigeria. The information collected included a brief medical examination, socio-economic data, food consumption pattern and a weighed food intake. Urban and rural children who drank school milk had a mean daily intake of 426 ml compared with only 185 ml per day for children who did not receive school milk. Children who drank school milk daily, when compared with those who did not, had higher statistically significant mean daily intake for several nutrients including calcium and riboflavin (p less than 0.001) in both sexes and groups; protein and fat for rural children (p less than 0.01) and vitamin A for urban and rural boys (p less than 0.001). Symptoms suggestive of lactose intolerance were low in the population investigated. The relative beneficial effects of milk supplementation were more marked in rural than in urban children.

Animals↗

Probiotics: functionality and commercial status.

Probiotics in the form of fermented milk products have been consumed for centuries. In this century various health benefits have been purported to result from consumption of foods containing live microorganisms, particularly lactic acid bacteria (LAB). Probiotics can provide relief for lactose intolerant individuals and reduce bouts of diarrhea. Evidence for other claims such as lowering serum cholesterol, suppressing cancer and stimulating the immune system remains to be clearly established by conducting well-controlled, statistically-valid clinical trials. Although the benefits to healthy individuals are uncertain, many consumers especially in Japan and Europe, perceive probiotic products to be healthful, and sales are robust.

Journal Article↗

Persistent diarrhea in the returned traveler.

In conclusion, the causes of chronic diarrhea in the returned traveler are protean. Careful evaluation requires an understanding of where the traveler has been, when they were there, the type of diarrheal illness, medications taken, and knowledge of the patients' other medical problems. Protozoa, particularly G. lamblia, C. parvum, and C. cayatenensis, are among the more commonly identified agents. If the patient is immunocompromised, microsporidia and Isospora become more likely, and a prior history of antimicrobial use raises the possibility of C. difficile colitis. Occasionally helminths, which establish intimate contact with the intestinal mucosa, may also cause prolonged diarrhea. If these and other gastrointestinal insults, such as tropical sprue, small bowel overgrowth, lactose intolerance, and processes unrelated to travel are excluded by more invasive studies or clinical history, the patient can be reassured that idiopathic chronic diarrhea is usually self-limited.

Animals↗

Effect of cow milk on pulmonary function in atopic asthmatic patients.

BACKGROUND: There is a perception by some asthmatic patients that stimulation of respiratory mucous production by cow milk may worsen airway obstruction. OBJECTIVE: To determine whether cow milk ingestion reduces bronchial airflow in asthmatic patients as measured by standard spirometry. METHODS: Twenty-five atopic adults with mild asthma but no history of cow milk allergy or lactose intolerance participated in a prospective, randomized, double-blind, placebo-controlled crossover study. Subjects were randomly assigned to ingest either a solution containing cow milk powder or a placebo solution, received neither during a 14-day washout period, then ingested the alternate solution. Forced vital capacity (FVC), forced expiratory volume in 1 second (s) (FEV1), and FEV1/FVC were measured at 30 minutes, 1 hour (h), and 7 hours after challenge. A > or = 20% decrease in FEV1 or FEV1/FVC was considered clinically significant. RESULTS: FEV1 was slightly lower at 30 minutes than the baseline value (mean change, .6% to 3.3%) for both challenges. None of the subjects experienced any adverse symptoms, acute or delayed, after cow milk or placebo challenges. Statistically significant changes in FEV1 were reached 30 minutes after cow milk challenge (P = .0007) and at one hour after placebo (P = .0027). These changes are not clinically significant. CONCLUSION: Although this study disclosed no acute or delayed asthmatic symptoms or deterioration of pulmonary function detected by using conventional spirometry, methacholine inhalation before and after cow milk challenge may be more sensitive for evaluation of cow milk-induced bronchial hyperreactivity.

Adult↗

One step partial purification of beta-D-galactosidase from Kluyveromyces marxianus CDB 002 using STREAMLINE-DEAE.

The intracellular enzyme beta-D-galactosidase provides interesting applications in the dairy industry, which are able to solve problems related to product processing, or can alleviate lactose intolerance in some populations. In order to obtain a technical enzyme, yeast cells of Kluyveromyces marxianus CDB 002 were disrupted by high pressure homogenization and an innovative chromatographic technique was tested for the recovery of beta-D-galactosidase. A STREAMLINE 25 column, containing 65 ml STREAMLINE-DEAE was equilibrated with 50 mM potassium phosphate buffer pH 7.5 at an upward flow of 250 cmh-1. 100-200 ml cell homogenate were applied onto the expanded gel. After unbound proteins and cellular debris were washed out, the bed was allowed to sediment and beta-D-galactosidase was eluted with a downward flow of 0.2 M NaCl in the same buffer. A 6-fold purification factor was achieved with 63% activity recovery, while removing cell debris at a single step, thus avoiding a centrifugation step. Concentration and volume of the applied sample affected purification and gel performance. The results presented show STREAMLINE-DEAE chromatography to be an interesting method for the production of beta-D-galactosidase as a technical enzyme, since it can also be applied on a large scale without much modification.

Biotechnology↗