Long-Term Transcriptomic Changes and Cardiomyocyte Hyperpolyploidy after Lactose Intolerance in Neonatal Rats.

Many cardiovascular diseases originate from growth retardation, inflammation, and malnutrition during early postnatal development. The nature of this phenomenon is not completely understood. Here we aimed to verify the hypothesis that systemic inflammation triggered by neonatal lactose intolerance (NLI) may exert long-term pathologic effects on cardiac developmental programs and cardiomyocyte transcriptome regulation. Using the rat model of NLI triggered by lactase overloading with lactose and the methods of cytophotometry, image analysis, and mRNA-seq, we evaluated cardiomyocyte ploidy, signs of DNA damage, and NLI-associated long-term transcriptomic changes of genes and gene modules that differed qualitatively (i.e., were switched on or switched off) in the experiment vs. the control. Our data indicated that NLI triggers the long-term animal growth retardation, cardiomyocyte hyperpolyploidy, and extensive transcriptomic rearrangements. Many of these rearrangements are known as manifestations of heart pathologies, including DNA and telomere instability, inflammation, fibrosis, and reactivation of fetal gene program. Moreover, bioinformatic analysis identified possible causes of these pathologic traits, including the impaired signaling via thyroid hormone, calcium, and glutathione. We also found transcriptomic manifestations of increased cardiomyocyte polyploidy, such as the induction of gene modules related to open chromatin, e.g., "negative regulation of chromosome organization", "transcription" and "ribosome biogenesis". These findings suggest that ploidy-related epigenetic alterations acquired in the neonatal period permanently rewire gene regulatory networks and alter cardiomyocyte transcriptome. Here we provided first evidence indicating that NLI can be an important trigger of developmental programming of adult cardiovascular disease. The obtained results can help to develop preventive strategies for reducing the NLI-associated adverse effects of inflammation on the developing cardiovascular system.

A comparison between lactose breath test and quick test on duodenal biopsies for diagnosing lactase deficiency in patients with self-reported lactose intolerance.

BACKGROUND: A lactose breath test (LBT) is usually used to diagnose lactase deficiency, and a lactose quick test (LQT) has been proposed as a new test on duodenal biopsies to detect this disorder. GOALS: We aimed to assess the diagnostic accuracy of LBT and LQT and their ability to predict the clinical response to a lactose-free diet in patients with self-reported lactose intolerance. STUDY: Fifty-five patients (age 47 ± 14 y; M/F 15/36) underwent upper gastrointestinal endoscopy and 25g-LBT. Two duodenal biopsies were taken to determine lactase deficiency (normal, mild, or severe) by LQT and to rule out other causes of secondary lactose malabsorption. Patients with a positive LBT and normal LQT also underwent a glucose breath test to exclude small intestinal bacterial overgrowth as a cause of the former result. The severity of gastrointestinal symptoms was measured with a GSS questionnaire, under basal condition and 1 month after a lactose-free diet. RESULTS: Lactose malabsorption was detected in 31/51 patients with LBT and in 37/51 patients with LQT (P = NS). Celiac disease was found in 2 patients. Two LBT+ patients showed a positive glucose breath test for small intestinal bacterial overgrowth. Eight patients had a mild hypolactasia by LQT and a negative LBT, but they had a significant improvement of symptoms after diet. LQT and LBT were concordant in 83% of cases and predicted the response to a lactose-free diet in 98% and 81% of the cases, respectively (P = 0.03). CONCLUSIONS: LQT is as sensitive as LBT in detecting lactase deficiency; however, it seems to be more accurate than LBT in predicting the clinical response to a lactose-free diet.

Two novel mutations in the lactase gene in a Japanese infant with congenital lactase deficiency.

Intestinal lactase is required for the hydrolysis of lactose that is the most essential carbohydrate in milk and the primary diet source of newborn. Congenital lactase deficiency [CLD (MIM 223000)] is a severe gastrointestinal disorder and is characterized by watery diarrhea due to an extremely low or the lack of lactase activity in the intestinal wall from birth. CLD is a rare disease and occurs more frequently in Finland. Recent studies have shown that mutations in the coding region of the lactase (LCT) gene underlie CLD in patients from Finland and other European countries. Here, we report two novel mutations in the LCT gene in a Japanese female infant with clinical features consistent with those of CLD. She suffered from severe watery diarrhea from the age of 2 days on breast milk/lactose containing cow's milk formula. With the lactose-free hydrolyzed cow's milk formula, diarrhea was stopped, and she has now developed well on a lactose-free diet. She shows a lactose-intolerance pattern on the lactose challenge test. Sequence analysis revealed the two mutations in her LCT gene: c.4419C>G (p.Y1473X) in exon 10 transmitted from her mother and c.5387delA (p.D1796fs) in exon 16 transmitted from her father. Both mutations cause premature truncation of lactase polypeptide and are supposed to be responsible for CLD. To our knowledge, this is the first report on mutations in the LCT gene in Japan. We suggest that an increased awareness is required regarding CLD.

Intestinal disaccharidase activity in patients with autism: effect of age, gender, and intestinal inflammation.

Intestinal disaccharidase activities were measured in 199 individuals with autism to determine the frequency of enzyme deficiency. All patients had duodenal biopsies that were evaluated morphologically and assayed for lactase, sucrase, and maltase activity. Frequency of lactase deficiency was 58% in autistic children ≤ 5 years old and 65% in older patients. As would be expected, patients with autism at age 5 > years demonstrated significant decline in lactase activity (24%, p = .02) in comparison with ≤ 5 years old autistic patients. Boys ≤ 5 years old with autism had 1.7 fold lower lactase activity than girls with autism (p = .02). Only 6% of autistic patients had intestinal inflammation. Lactase deficiency not associated with intestinal inflammation or injury is common in autistic children and may contribute to abdominal discomfort, pain and observed aberrant behavior. Most autistic children with lactose intolerance are not identified by clinical history.

A biopsy-based quick test in the diagnosis of duodenal hypolactasia in upper gastrointestinal endoscopy.

BACKGROUND AND STUDY AIMS: The usefulness of a new quick test for endoscopic diagnosis of adult-type hypolactasia was tested in duodenal biopsies. In this test, an endoscopic biopsy from the postbulbar duodenum is incubated with lactose on a test plate, and a color reaction develops within 20 min as a result of hydrolyzed lactose (a positive result) in patients with normolactasia, whereas no reaction (a negative result) develops in patients with severe hypolactasia. PATIENTS AND METHODS: Two postbulbar duodenal biopsies were taken from 80 prospectively enrolled adult outpatients with dyspepsia. The biopsies were used for the Quick Lactase Test (Biohit PLC, Helsinki, Finland) and in biochemical disaccharidase (lactase, sucrase, and maltase) assays. In addition, the C/T (-13,910) genotype was determined from DNA extracted from gastric antral biopsies using polymerase chain reaction sequencing in genomic analysis of adult-type hypolactasia. RESULTS: Twenty-one of 22 patients (95 %; 95 % CI, 87 - 100 %) with biochemical lactase activity < 10 U/g protein, but none of the 58 patients with lactase activity of 10 U/g protein or more had a negative result in the Quick Lactase Test. Seven of the 80 patients (9 %; 95 % CI, 3 - 15 %) had a Quick Lactase Test result that indicated mild hypolactasia (a mild color reaction). All patients with celiac disease (n = 6) had a negative Quick Lactase Test result. Nine of 74 patients (six patients with celiac disease were excluded) had a CC (-13,910) genotype in genomic testing, indicating adult-type hypolactasia. All of them had negative test results with the Quick Lactase Test. Twenty-six patients had a TT genotype, indicating normolactasia, and none of these patients had a negative test result in the Quick Lactase Test. Six of 39 patients (15 %; 95 % CI, 4 - 27 %) with a CT genotype had a negative result in the Quick Lactase Test. CONCLUSIONS: The Quick Lactase Test effectively identifies patients with severe duodenal hypolactasia. In comparison with CC (adult-type hypolactasia) and TT individuals (normolactasia), the sensitivity and specificity of the Quick Lactase Test result was 100 %. In comparison with biochemical lactase assays, the sensitivity and specificity of a negative Quick Lactase Test for indicating hypolactasia (lactase activity < 10 U/g protein) were 95 % (95 % CI, 87 - 100 %) and 100 %, respectively.

The molecular basis of lactose intolerance.

A staggering 4000 million people cannot digest lactose, the sugar in milk, properly. All mammals, apart from white Northern Europeans and few tribes in Africa and Asia, lose most of their lactase, the enzyme that cleaves lactose into galactose and glucose, after weaning. Lactose intolerance causes gut and a range of systemic symptoms, though the threshold to lactose varies considerably between ethnic groups and individuals within a group. The molecular basis of inherited hypolactasia has yet to be identified, though two polymorphisms in the introns of a helicase upstream from the lactase gene correlate closely with hypolactasia, and thus lactose intolerance. The symptoms of lactose intolerance are caused by gases and toxins produced by anaerobic bacteria in the large intestine. Bacterial toxins may play a key role in several other diseases, such as diabetes, rheumatoid arthritis, multiple sclerosis and some cancers. The problem of lactose intolerance has been exacerbated because of the addition of products containing lactose to various foods and drinks without being on the label. Lactose intolerance fits exactly the illness that Charles Darwin suffered from for over 40 years, and yet was never diagnosed. Darwin missed something else--the key to our own evolution--the Rubicon some 300 million years ago that produced lactose and lactase in sufficient amounts to be susceptible to natural selection.

Lactose intolerance and intestinal villi morphology in Thai people.

OBJECTIVE: To study the relationship of lactose intolerance and intestinal villi morphology in Thai people. MATERIAL AND METHOD: Subjects for this study were patients with functional dyspepsia who had no history of milk allergy and underwent gastroduodenoscopy. Two mucosal biopsy specimens were taken from beyond the distal end of the second part of the duodenum. The specimens were carefully orientated and were graded according to the following scheme: group I: finger shaped villi; group II: mixed finger and leaf shaped villi; group III: clubbing or blunting shaped villi. All subjects were tested for lactose malabsorption by breath hydrogen analysis after consuming 50 gram lactose. Breath hydrogen concentration was analyzed in samples collected intermittently by end-expiratory technique. A rise in breath hydrogen concentration of 20 PPM over baseline was considered evidence of lactose malabsorption. RESULTS: The twenty-five subjects were twenty females (80.0%) and five males (20.0%) who ranged in age from 18 to 53 years (mean 31 +/- 8.29). Sixteen subjects belonged to the finger shaped villi group (64.0%), five to the mixed finger and leaf shaped villi, group (20.0%) and four to the clubbing or blunting shaped villi group (16.0%). Results of breath hydrogen excretion test identified the prevalence of lactose intolerance in 68 per cent of the subjects: 15/16 (93.75%) of group I; 1/5 (20.0%) of group II and 1/4 (25%) of group III respectively (P<0.001). The symptom of diarrhea after lactose loading was correlated well in patients who had positive breath hydrogen analysis. CONCLUSION: As shown in this study, the lactose intolerance is not related to intestinal villi morphology. It is implied that primary lactase deficiency is more common in Thai people than secondary lactase deficiency.

A retrospective assessment of the clinical value of jejunal disaccharidase analysis.

BACKGROUND: The measurement of jejunal disaccharidases is used by several gastroenterologists when investigating suspected small-bowel disease. The clinical value of this analysis is assessed. METHOD: The histology and disaccharidase results in 1585 jejunal biopsy specimens were reviewed retrospectively. RESULTS: Disaccharidase and histology results concurred in most cases (72%). However, disaccharidases were an insensitive indicator of small-bowel disease: low levels were found in only 65% of coeliac patients with villous atrophy, 15% of patients with giardiasis, and 6% of patients with villous atrophy associated with non-coeliac histology. Low disaccharidase levels were sometimes found in patients with normal histology (1.6%) and when biopsy specimens were unwittingly taken from non-jejunal sites (1.4%). Isolated low lactase activities were found in 3.2%. Usually this finding was not clinically relevant because patients had no symptoms of lactose intolerance (38%), had another diagnosis that responded to appropriate treatment (8%), or had no response to a low-lactose diet (14%). In 16 patients sucrase activities were markedly low, and this investigation proved central to the diagnosis of sucrase-alpha-dextrinase deficiency, which was subsequently confirmed in 9. CONCLUSION: Jejunal disaccharidases are clinically useful only in the diagnosis of sucrase-alpha-dextrinase deficiency. We recommend that their measurement be reserved for the investigation of patients suspected of having this condition.

Influence of cow's milk proteins and gluten on human duodenal mucosa in organ culture.

Forty-five duodenal biopsies from 33 children and 3 adult patients were maintained in organ culture for 24 h and exposed to various cow's milk proteins and gluten. In 10 of 11 celiac patients with a flat duodenal mucosa, and in 2 of 4 patients with partial villous atrophy, a significant reduction in the mean enterocyte height was found after in vitro gluten exposure, compared to culture in basic culture medium. Three patients had coexisting celiac disease and cow's milk protein intolerance. alpha-Lactalbumin and beta-lactoglobulin exhibited toxic effects on flat biopsies from two of these patients, and casein was toxic in one. In 10 patients with cow's milk protein intolerance, a significant reduction in enterocyte height was noted in one case with gluten, and in three patients with casein and lactoglobulin, whereas lactalbumin did not affect the tissues. In seven control patients having a normal duodenal mucosa, no in vitro influences were noted, whereas in four patients with partial villous atrophy, a toxic reaction to gluten was seen in one and a reduced enterocyte height was seen after lactoglobulin exposure in another. In vitro toxicity induced by gluten corresponded well with the diagnosis of celiac disease, whereas toxic reactions to cow's milk proteins during organ culture were inconsistent in cow's milk intolerance, except for cases in which a marked enteropathy was documented.

Is the assay of disaccharidase activity in small bowel mucosal biopsy relevant for clinical gastroenterologists?

In a retrospective study, jejunal mucosal disaccharidase and alkaline phosphatase activities have been investigated in 40 controls and patients with proven celiac sprue (n = 26), lactase deficiency (n = 26), osteoporosis or osteomalacia (n = 16), chronic pancreatitis (n = 12), giardiasis (n = 7), or Crohn's disease (n = 7). Apart from a nonselective reduction of mucosal enzyme activities in the sprue syndrome and a selective reduction of lactase activity in the patients with primary lactase deficiency, assays of mucosal disaccharidases revealed only inconstant or slight deviations from the control group and were not of diagnostic significance for any of the above-mentioned disorders. Isolated forms of enzyme deficiencies other than lactase deficiency, such as sucrase-isomaltase or trehalase deficiency were not present among 168 investigations carried out from 1972-1982. It is concluded that assay of small intestinal disaccharidase or alkaline phosphatase activities does not expand the diagnostic impact of morphological examination of small bowel biopsy specimens and modern noninvasive methods for the detection of carbohydrate malabsorption. Thus, the method does not appear a necessary or relevant investigation in routine clinical practice.

Lactose malabsorption in adult patients with Crohn's disease.

In order to evaluate, in adult patients with Crohn's disease (CD), the prevalence of lactose malabsorption and intolerance, and the percentage who can tolerate a physiologic amount of milk in their diet, we tested 37 patients with CD (19 with intestinal resection, and 18 without) and 67 healthy controls (C) with the H2-breath test after they had ingested increasing loads of lactose as 10% solution (12.5 g, 25 g, and 50 g). Patients with malabsorption after the 12.5-g dose were tested further with 250 ml of milk. In the total group of patients and in the subgroup of those with resection, the prevalence of malabsorption was higher than in controls at all lactose loads; in patients who had not undergone resection, no significant difference was observed with the 12.5-g dose. Eleven of 18 patients who were malabsorbers with the 12.5-g dose had malabsorption also with 250 ml milk; however, only three of them (8% of the total group) experienced symptoms of intolerance. We conclude that, in adult patients with CD, 1) the prevalence of lactose malabsorption is increased, 2) in patients who have undergone intestinal resection, malabsorption occurs at a lower dose of the sugar than in patients who did not, and 3) since only 8% of patients experienced symptoms of intolerance after the ingestion of milk 250 ml, this amount can be empirically inserted in the daily diet of an adult with CD.

Effect of continued feeding of cows' milk on asymptomatic infants with milk protein sensitive enteropathy.

The clinical response and the histological changes in the mucosa of the small bowel in response to continued feeding with cows' milk protein were assessed over a period of 2-6 weeks in 24 infants who had shown histological changes without immediate clinical symptoms after challenge with a diet containing cows' milk protein. Twenty of the 24 infants (83%) thrived well on cows' milk protein. Jejunal biopsy specimens taken six to eight weeks after the initial biopsy showed histological improvement in all 20 infants compared with biopsy specimens taken soon after the challenge, which had shown mucosal damage. The mucosa had returned to normal in 12, was mildly abnormal in seven, and moderately abnormal in one. Corresponding improvements in the activities of mucosal enzymes were seen. In four of the 24 infants (17%) symptoms developed between three and six weeks. Histological examination of the jejunal biopsy specimens showed that mucosal damage had progressed in two, and remained the same in two; moreover, the disaccharidase activities remained depressed. The present study shows that most infants with enteropathy caused by sensitivity to cows' milk protein but without clinical symptoms develop tolerance to the protein and the mucosa returns to normal despite continued feeding with cows' milk protein.

Differences between lactase deficient and non-lactase deficient women with spinal osteoporosis.

Both osteoporosis and lactase deficiency are seen commonly in the United States. Since the latter may lead to avoidance of calcium sources and may exacerbate the bone disease in populations at risk, we studied lactose tolerance and histomorphometrically analyzed undecalcified transiliac bone biopsies in a consecutive group of postmenopausal women with the osteoporotic spinal compression fracture syndrome. Oral lactose tolerance tests prior to the biopsy clearly separated two groups. Sixty-five percent had abnormal test results. The bone biopsies in the lactase deficient group showed more osteoid volume and osteoid seam widths on examined trabecular bone. Analysis of tetracycline-labeled bone revealed significant increases in both single, double, combined single and double tetracycline labels, and the percent osteoid labeled with tetracycline. There was no difference in the calcification rates. These findings indicate different mineralization activity in lactase deficient patients, possibly reflecting their lower dietary calcium intake.

Cow's milk protein-sensitive enteropathy: number and timing of biopsies for diagnosis.

Intestinal biopsy is an essential procedure in the diagnosis of cow's milk protein-sensitive enteropathy. The number and timing of biopsies, however, is still controversial. Twenty-two infants who were clinically suspected of having cow's milk protein intolerance were put on a milk-free diet, during which they all improved. In the first 14 infants (Group I), milk withdrawal lasted 6-8 weeks; in the following 8 infants (Group II), milk withdrawal lasted 3.5-4 months. At the end of the withdrawal period, each patient was submitted to an oral lactose tolerance test and then to a first jejunal biopsy, followed by a cow's milk challenge, and a second biopsy (1-2 days later). None of the infants showed evidence of lactose intolerance, but they all reacted adversely to milk reintroduction. In Group I, the distribution of mucosae from grade 0 (normal) to III was almost the same before and after challenge (p greater than 0.5); this is considered to be due to the severe mucosal damage still present in prechallenge biopsies. In Group II, however, a significant difference was found in the distribution of mucosae before and after challenge (p less than 0.05), and a deterioration could be observed in each case after challenge. Intraepithelial lymphocyte counts and mitotic index determinations before and after milk reintroduction were of no diagnostic value in either group. It is suggested that the diagnosis of cow's milk protein-sensitive enteropathy may rely on two biopsies, the first after a period of 3.5-4 months on milk-free diet and the second following milk challenge.

Value of breath hydrogen analysis in management of diarrheal illness in childhood: comparison with duodenal biopsy.

Breath hydrogen tests were carried out on 157 children either because they had chronic diarrhea or because they were on disaccharide-free diets. Lactose malabsorption was common in patients with postgastroenteritis syndrome (43%), and sucrose malabsorption was readily detected in patients with congenital sucrase-isomaltase deficiency. Secondary sucrose malabsorption and small bowel bacterial overgrowth were also detected. In predicting clinical response to dietary change, the breath hydrogen test, as we perform it, was clearly the most specific and sensitive and had a predictive accuracy of 96%. Duodenal biopsy results obtained from 48 of the children gave a 23% incidence of misleading disaccharidase results (16.7% falsely normal, 6.3% falsely abnormal), but biopsy remains vital in the diagnosis of congenital sucrase-isomaltase deficiency. False negative breath hydrogen results were obtained on occasions (4%) but in most instances were related to recent antimicrobial therapy or failure of the breath test mechanics (e.g., vomiting, length of sampling).

Ultrastructural study on a severe infantile sialidosis (beta-galactosidase-alpha-neuraminidase deficiency).

This study was undertaken to elucidate ultrastructural changes in a severe infantile sialidosis. The materials examined in this study consisted of biopsied rectal mucosa and autopsied small intestine, liver and kidney. In the biopsy sample, axons contained a number of pleomorphic electron dense bodies, and numerous membrane-bound vacuoles were found in Schwann's cells, fibroblasts, endothelial cells, lymphocytes and plasma cells. In autopsy samples, neurons in Auerbach's myenteric plexus of the small intestine were filled with a number of membranous cytoplasmic bodies, pleomorphic dense bodies and vesicles containing dense materials. Hepatocytes in the liver, and glomerular and tubular epithelial cells in the kidney were also extended by a number of membrane-bound vacuoles. These ultrastructural changes in severe infantile sialidosis closely resemble those in GM1-gangliosidosis type 1.

Diagnostic role of skin or conjunctival biopsies in neurological disorders. An update.

Updated figures from our reports on electron microscopy of skin or conjunctival biopsies include 256 patients, mostly suffering from lysosomal diseases. Significant morphological data supportive of the diagnosis and additional to enzyme assay (when and if an assay is available for the disorder) were discovered in 95% of the cases. Equivocal or negative data amounted to 5%. The present paper deals with some metabolic disorders which had not been fully dealt with in our previous publications and with an extension of the indications of skin biopsies: adult form and atypical variants of ceroid-lipofuscinoses, galactosialidosis, mucolipidosis IV, infantile neuroaxonal dystrophy, Lafora's disease, cardiomyopathy with generalized accumulation of intermediate filaments and congenital hypomyelination neuropathy. A comparison between biopsy and autopsy material in storage diseases shows that the storage of inclusions does not remain limited to one cell type or to one tissue even if no clinical signs are detectable. This ubiquitous character of the storage can be used for diagnostic purposes. On the other hand, the membrane-bound inclusions are not necessarily similar in all cell types and the search for characteristic features can be difficult in adult patients. Finally it is evident that skin biopsies can be used in other conditions than lysosomal disorders. The applicability of this procedure to other diseases needs further exploratory work.