Milk Containing A2 β-Casein ONLY, as a Single Meal, Causes Fewer Symptoms of Lactose Intolerance than Milk Containing A1 and A2 β-Caseins in Subjects with Lactose Maldigestion and Intolerance: A Randomized, Double-Blind, Crossover Trial

Acute-feeding and multiple-day studies have demonstrated that milk containing A2 β-casein only causes fewer symptoms of lactose intolerance (LI) than milk containing both A1 and A2 β-caseins. We conducted a single-meal study to evaluate the gastrointestinal (GI) tolerance of milk containing different concentrations of A1 and A2 β-casein proteins. This was a randomized, double-blind, crossover trial in 25 LI subjects with maldigestion and an additional eight lactose maldigesters who did not meet the QLCSS criteria. Subjects received each of four types of milk (milk containing A2 β-casein protein only, Jersey milk, conventional milk, and lactose-free milk) after overnight fasting. Symptoms of GI intolerance and breath hydrogen concentrations were analyzed for 6 h after ingestion of each type of milk. In an analysis of the 25 LI subjects, total symptom score for abdominal pain was lower following consumption of milk containing A2 β-casein only, compared with conventional milk (p = 0.004). Post hoc analysis with lactose maldigesters revealed statistically significantly improved symptom scores (p = 0.04) and lower hydrogen production (p = 0.04) following consumption of milk containing A2 β-casein only compared with conventional milk. Consumption of milk containing A2 β-casein only is associated with fewer GI symptoms than consumption of conventional milk in lactose maldigesters.

Efficacy of gluten- and casein-free diets on autism spectrum disorders in children

Food containing gluten and casein could play a role in autism spectrum disorders (ASD) symptoms. The present review aimed to update the evidence about the role of the gluten- and casein-free diet (GCFD) on the management of ASD. Web of Science, Science Direct, Google Scholar, and PubMed databases were used to search for randomized controlled trials (RCT) conducted between January 2000 and February 2020. In total, 9 RCT were included (521 participants) with age range between 2 to 18 years. Four of these studies did not show a significant improvement regarding the symptoms of ASD. The rest of these studies (n=5) showed improvement in communication, stereotyped movements, aggressiveness, language, hyperactivity, tantrums, and signs of attention deficit hyperactivity disorder compared to control group. Hence, the data remains insufficient to support the use of GCFD to improve the symptoms of ASD in children.

N-acetylcysteine (NAC), an anti-oxidant, does not improve bone mechanical properties in a rat model of progressive chronic kidney disease-mineral bone disorder

Individuals with chronic kidney disease have elevated levels of oxidative stress and are at a significantly higher risk of skeletal fracture. Advanced glycation end products (AGEs), which accumulate in bone and compromise mechanical properties, are known to be driven in part by oxidative stress. The goal of this study was to study effects of N-acetylcysteine (NAC) on reducing oxidative stress and improving various bone parameters, most specifically mechanical properties, in an animal model of progressive CKD. Male Cy/+ (CKD) rats and unaffected littermates were untreated (controls) or treated with NAC (80 mg/kg, IP) from 30 to 35 weeks of age. Endpoint measures included serum biochemistries, assessments of systemic oxidative stress, bone morphology, and mechanical properties, and AGE levels in the bone. CKD rats had the expected phenotype that included low kidney function, elevated parathyroid hormone, higher cortical porosity, and compromised mechanical properties. NAC treatment had mixed effects on oxidative stress markers, significantly reducing TBARS (a measure of lipid peroxidation) while not affecting 8-OHdG (a marker of DNA oxidation) levels. AGE levels in the bone were elevated in CKD animals and were reduced with NAC although this did not translate to a benefit in bone mechanical properties. In conclusion, NAC failed to significantly improve bone architecture/geometry/mechanical properties in our rat model of progressive CKD.

Changes in chemical and ultrastructural composition of ameroid constrictors following in vitro expansion

OBJECTIVE

To (1) characterise the chemical and ultra-structural composition of ameroid constrictors, at a native state and during in vitro expansion and (2) determine the presence of irritant compounds at the surface or within the bulk of the constrictor.

METHODS

Twelve sterile, commercially packaged ameroid constrictors (3 repeats of 3.5 mm, 5 mm, 6 mm and 7 mm internal diameter) were analysed by time-of-flight secondary ion mass spectrometry, Raman spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy and scanning electron microscopy.

RESULTS

Ameroid constrictors have a composition commensurate with casein with little-to-no intra- or inter- constrictor variation. Microscopic analysis indicated that the topographical features of the constrictor surfaces were consistent between all constrictors. Following in vitro expansion there was a reproducible decrease in Ca+ ion content, little-to-no variation in secondary protein structure and morphological changes including the presence of surface aggregates present only at the inner surface of the ameroid constrictor. The potential irritant polydimethylsiloxane was found on the constrictor surface. A trace quantity of an ion fragment assigned as formaldehyde was detected; however, the extremely low level is thought highly unlikely to play a role as an inflammatory trigger clinically.

DISCUSSION

There is a high degree of inter- and intra-constrictor homogeneity from different batches, and reproducible ultrastructural changes following in vitro expansion. Variations occur in both the surface chemistry and topography of the device during closure, which can potentially affect the biomaterial-host interface. Ameroid constrictor closure mechanism is likely involving calcium-mediated inter-protein interactions rather than the imbibition of water only.

Mixed compared with single-source proteins in high-protein diets affect kidney structure and function differentially in obese fa/fa Zucker rats

Questions remain regarding the potential negative effects of dietary high protein (HP) on kidney health, particularly in the context of obesity in which the risk for renal disease is already increased. To examine whether some of the variability in HP effects on kidney health may be due to source of protein, obese fa/fa Zucker rats were given HP (35% of energy from protein) diets containing either casein, soy protein, or a mixed source of animal and plant proteins for 12 weeks. Control lean and obese rats were given diets containing casein at normal protein (15% of energy from protein) levels. Body weight and blood pressure were measured, and markers of renal structural changes, damage, and function were assessed. Obesity alone resulted in mild renal changes, as evidenced by higher kidney weights, proteinuria, and glomerular volumes. In obese rats, increasing the protein level using the single, but not mixed, protein sources resulted in higher renal fibrosis compared with the lean rats. The mixed-protein HP group also had lower levels of serum monocyte chemoattractant protein-1, even though this diet further increased kidney and glomerular size. Soy and mixed-protein HP diets also resulted in a small number of damaged glomeruli, while soy compared with mixed-protein HP diet delayed the increase in blood pressure over time. Since obesity itself confers added risk of renal disease, an HP diet from mixed-protein sources that enables weight loss but has fewer risks to renal health may be advantageous.

Parasympathetic nervous system involvement in food allergy: description of a paediatric case

The latest research data emphasize the interaction between the nervous and the immune systems. It has been demonstrated that the central nervous system (CNS) can be involved secondarily due to blood brain barrier (BBB) disruption via pro-inflammatory cytokines released in allergy. More recently it was demonstrated that the parasympathetic nervous system (PNS) could also be equally involved in models of peripheral inflammation such as food allergy; although this last clinical presentation has rarely been described. Herein, the authors report the case of a five-year-old Caucasian female who was admitted to our Pediatric Acute and Emergency Operative Unit for cyclic vomiting. Her vomiting, which was preceded by objective torque vertigo, headache and weakness, had been recurring with constant frequency every two months since she was 3 years old. After a complex diagnostic flow-chart, it was found that this spectrum of neurologic symptoms was due to a food allergy syndrome, which postulates some etiopathogenic hypotheses to explain the relationship between the two mentioned diseases.

[Lactose intolerance]

The most common problem limiting milk consumption worldwide is lactose intolerance (LI), which is defined as the experience of gastrointestinal symptoms due to the intake of lactose-containing food. When symptoms ensue the intake of milk, the condition is referred as milk intolerance, and it may or may not be due to LI. The most common cause of LI is primary lactase deficiency which occurs in 30% of Mexican adults when one glass of milk is consumed (12-18 g of lactose). LI occurs in less than 15% of adults after the intake of this dose of lactose. Another cause of lactose intolerance is due to secondary lactase deficiency, which occurs because lactase is reduced due to diseases that affect the intestinal mucosa. Lactose intolerance can be eliminated or significantly reduced by elimination or reduction of the intake of milk and milk containing products. Recent studies demonstrate that when β-casein-A1 contained in milk is hydrolyzed it produces β-casomorphine-7 which is an opioid associated with milk intolerance.

The Interactions of CPP-ACP with Saliva

The repair of early dental caries lesions has been demonstrated by the application of the remineralisation technology based on casein phosphopeptide-stabilised amorphous calcium phosphate complexes (CPP-ACP). These complexes consist of an amorphous calcium phosphate mineral phase stabilised and encapsulated by the self-assembly of milk-derived phosphopeptides. During topical application of CPP-ACP complexes in the oral cavity, the CPP encounters the enamel pellicle consisting of salivary proteins and peptides. However the interactions of the CPP with the enamel salivary pellicle are not known. The studies presented here reveal that the predominant peptides of CPP-ACP complexes do interact with specific salivary proteins and peptides of the enamel pellicle, and provide a mechanism by which the CPP-ACP complexes are localised at the tooth surface to promote remineralisation.

Gluten and casein supplementation does not increase symptoms in children with autism spectrum disorder

AIM

A gluten- and casein-free diet is often given to children with autism spectrum disorder (ASD). We aimed to determine the effect of gluten and casein supplementation on maladaptive behaviour, gastrointestinal symptom severity and intestinal fatty acids binding protein (I-FABP) excretion in children with ASD.

METHODS

A randomised, controlled, double-blind trial was performed on 74 children with ASD with severe maladaptive behaviour and increased urinary I-FABP. Subjects were randomised to receive gluten-casein or a placebo for seven days. We evaluated maladaptive behaviour before and after supplementation, using I-FABP excretion, the approach withdrawal problem composite subtest of the Pervasive Developmental Disorder Behavior Inventory and the Gastrointestinal Symptom Severity Index.

RESULTS

The mean approach withdrawal problem composite score was significantly higher before supplementation than after, both in the placebo and in the gluten-casein group. However, the mean difference was not significant and may have been caused by additional therapy. There was no significant difference in gastrointestinal symptoms and urinary I-FABP excretion.

CONCLUSION

Administrating gluten-casein to children with ASD for one week did not increase maladaptive behaviour, gastrointestinal symptom severity or urinary I-FABP excretion. The effect of prolonged administration or other mechanisms of enterocyte damage in ASD should be explored.

Milk Intolerance, Beta-Casein and Lactose

True lactose intolerance (symptoms stemming from lactose malabsorption) is less common than is widely perceived, and should be viewed as just one potential cause of cows’ milk intolerance. There is increasing evidence that A1 beta-casein, a protein produced by a major proportion of European-origin cattle but not purebred Asian or African cattle, is also associated with cows’ milk intolerance. In humans, digestion of bovine A1 beta-casein, but not the alternative A2 beta-casein, releases beta-casomorphin-7, which activates μ-opioid receptors expressed throughout the gastrointestinal tract and body. Studies in rodents show that milk containing A1 beta-casein significantly increases gastrointestinal transit time, production of dipeptidyl peptidase-4 and the inflammatory marker myeloperoxidase compared with milk containing A2 beta-casein. Co-administration of the opioid receptor antagonist naloxone blocks the myeloperoxidase and gastrointestinal motility effects, indicating opioid signaling pathway involvement. In humans, a double-blind, randomized cross-over study showed that participants consuming A1 beta-casein type cows’ milk experienced statistically significantly higher Bristol stool values compared with those receiving A2 beta-casein milk. Additionally, a statistically significant positive association between abdominal pain and stool consistency was observed when participants consumed the A1 but not the A2 diet. Further studies of the role of A1 beta-casein in milk intolerance are needed.

Resistant starch prevents colonic DNA damage induced by high dietary cooked red meat or casein in rats

In a previous study we have shown that high levels of dietary protein (as casein) result in increased levels of colonic DNA damage, measured by the comet assay, and thinning of the colonic mucus layer in rats when dietary resistant starch (RS) is negligible. Feeding RS abolishes these effects. This study aimed to establish whether a diet high in protein as cooked red meat would have similar effects and whether RS was protective. Rats were fed a diet containing 15% or 25% casein or 25% cooked lean red beef, each with or without the addition of 48% high amylose maize starch (a rich source of RS) for four weeks. As expected, high dietary casein caused a 2-fold increase in colonic DNA damage compared with a low casein diet and reduced the thickness of the colonic mucus layer by 41%. High levels of cooked meat caused 26% greater DNA damage than the high casein diet but reduced mucus thickness to a similar degree to casein. Addition of RS to the diet abolished the increase in DNA damage and the loss of colonic mucus thickness induced by either high protein diet. Cecal and fecal short chain fatty acid pools were also increased by inclusion of RS in the diet. Because DNA damage is an early step in the initiation of cancer, these findings suggest that increased DNA damage due to high dietary protein as cooked red meat or casein could increase colorectal cancer risk but inclusion of resistant starch in the diet could significantly reduce that risk.

Comparative evaluation of cow β-casein variants (A1/A2) consumption on Th2-mediated inflammatory response in mouse gut

PURPOSE

Recently, apprehension has been raised regarding "A1/A2 hypothesis" suggesting relationship between consumption of A1 "like" variants of cow β-casein and various physiological disorders. The information available is based on either the human epidemiological data of milk consumption or in vitro trials on cell lines with β-casomorphin peptides. The direct scientific evidence establishing the link between consumption of A1/A2 "like" milk and health is scanty. Thus, under present investigation, in vivo trials in mice were undertaken to study the effect of feeding three genetic variants (A1A1, A1A2 and A2A2) of cow β-casein milk on gastrointestinal immune system as it is the first and foremost site of immunological interactions.

METHODS

Animals were divided into four groups for feeding with basal diet (control) and β-casein isolated from milk of genotyped (A1A1, A1A2 and A2A2) dairy animals, respectively. Gut immune response was analyzed by spectrophotometric assessment of MPO activity, quantitative sandwich ELISA of inflammatory cytokines (MCP-1 and IL-4), antibodies (total IgE, IgG, sIgA, IgG1 and IgG2a) and qRT-PCR of mRNA expression for toll-like receptors (TLR-2 and TLR-4). Histological enumeration of goblet cells, total leukocytes and IgA(+) cells was also carried out.

RESULTS

It was observed that consumption of A1 "like" variants (A1A1 and A1A2) significantly increased (p < 0.01) the levels of MPO, MCP-1, IL-4, total IgE, IgG, IgG1, IgG2a and leukocyte infiltration in intestine. TLR-2 and TLR-4 mRNA expression was also up-regulated (p < 0.01) on administration of A1 "like" variants. However, no changes in sIgA, IgA(+) and goblet cell numbers were recorded on consumption of any of the β-casein variants.

CONCLUSION

It is reasonable to conclude that consumption of A1 "like" variants of β-casein induced inflammatory response in gut by activating Th2 pathway as compared to A2A2 variants. The present study thus supports the purported deleterious impacts of consumption of A1 "like" variants of β-casein and suggests possible aggravation of inflammatory response for etiology of various health disorders.

A novel protein mixture containing vegetable proteins renders enteral nutrition products non-coagulating after in vitro gastric digestion

BACKGROUND & AIMS

Non-coagulation of protein from enteral nutrition (EN) in the stomach is considered to improve gastric emptying and may result in reduced upper gastrointestinal complications such as reflux and aspiration pneumonia. For the development of a new EN protein mixture with reduced gastric coagulation, the coagulating properties of individual proteins, a novel blend of four proteins (P4 protein blend) and commercial EN products were investigated.

METHODS

A semi-dynamic, computer controlled setup was developed to mimic gastric digestion. The coagulation behaviour of 150 ml protein solutions and EN products was investigated. These were heat-treated calcium caseinate, sodium caseinate, whey, soy and pea protein, and the P4 protein blend comprising of the latter four (all solutions 6% w/v protein), four new enteral nutrition product varieties (New Nutrison® .0 or 1.5 kcal/ml, with and without MultiFibre MF6™) based on the P4 protein blend and two other commercially available casein dominant EN products (T1 and T2).

RESULTS

Calcium caseinate and sodium caseinate yielded a total wet coagulate of 43.5 ± 0.7 g and 52.7 ± 6.2 g, respectively. Whey, soy, pea and the P4 protein blend did not produce any measurable coagulate. T1 and T2 resulted in a total wet coagulate of 37.5 ± 0.8 g and 57.3 ± 0.8 g, respectively, while all new EN product varieties based on the P4 protein blend did not produce any measurable coagulate.

CONCLUSIONS

The P4 protein blend renders EN product varieties non-coagulating after in vitro gastric digestion.

Effect of thermal processing of cow and buffalo milk on the allergenic response to caseins and whey proteins in mice

BACKGROUND

Heat treatment is the most common method for reducing pathogen load, but it remains controversial in reducing the incidence of hyperimmune reactions. The aim of this study was to compare the allergenicity of caseins (CSN) and whey proteins (WP) of thermally processed cow and buffalo milk in a mouse model. Swiss albino mice were sensitised by intraperitoneal injections (administered in three doses at weekly intervals) of CSN or WP from cow or buffalo milk for the evaluation of humoral response and splenocyte stimulation index.

RESULTS

After 3 weeks of intraperitoneal stimulation of mice with milk proteins, the sterilised milk protein group displayed significantly lowered (P ≤ 0.05) serum IgG and IgE levels, while considerably increased cow milk protein-specific responses (IgE) were shown by proteins of pasteurised milk compared with those of raw milk. The stimulation index of splenocytes induced by CSN or WP of boiled and sterilised milk was also lower (P ≤ 0.05) than that of raw milk of both cow and buffalo.

CONCLUSION

The experiment showed that boiling and sterilisation of cow and buffalo milk clearly affect the allergenicity by decreasing the humoral and cell-mediated responses in mice. All results indicated that CSN and WP of sterilised milk are less allergenic than those of raw milk in mice.

Quantification of allergenic bovine milk α(S1)-casein in baked goods using an intact ¹⁵N-labeled protein internal standard

Intact bovine ¹⁵N-α(S1)-casein was used as an internal standard in a selected reaction monitoring (SRM) assay for milk protein in baked food samples containing fats, sugar, and gums. Effects on SRM results of sample matrix composition in two biscuit recipes containing nonfat dry milk (NFDM) were studied, including samples from a milk allergen ELISA proficiency trial. Following extraction of defatted samples with carbohydrate-degrading enzymes and acid precipitation of casein, the SRM assay exhibited an LOQ of <3 ppm NFDM with 60-80% recovery. NFDM levels measured by the SRM assay were 1.7-2.5 times greater than median levels determined by ELISA. Differences were observed in the α(S1)-casein interpeptide SRM ion abundance profile between recipes and after baking. ¹⁵N-α(S1)-Casein increases SRM analysis accuracy by correcting for extraction recovery but does not eliminate underestimation of allergen concentrations due to baking-related milk protein transformation (modifications).

Chicken-based formula is better tolerated than extensively hydrolyzed casein formula for the management of cow milk protein allergy in infants

The effective treatment of cow milk allergy in infants consists of elimination of cow milk protein and the introduction of formulas based on an extensively hydrolyzed protein formula or an amino acid-based formula. However, about 10% of these infants are still allergic to an extensively hydrolyzed protein formula and an amino acid-based formula is very expensive. We conducted a study to verify whether the new chicken-based formula will be better tolerated than an extensively hydrolyzed protein formula for the treatment of cow milk allergy in infants. One hundred infants, diagnosed with cow milk allergy by double-blind, placebo-controlled food challenge tests, were enrolled in a double-blind, randomized, cross-over study to compare a response to an extensively hydrolyzed protein formula and the chicken-based formula. Subjects were randomly given one of the two formulas for 2 weeks. There was a 2-week washout period of taking an amino acid-based formula before being switched to the other formula for another 2 weeks. If the subjects showed allergic symptoms during the 2 weeks of test formula, they would be announced as intolerance or allergic to that formula. Sixty seven of 80 confirmed subjects agreed to enroll their infants. Fifty-eight subjects completed the study. Twenty and 33 infants were tolerant whereas and 38 and 25 infants were intolerant to an extensively hydrolyzed protein formula and the chicken-based formula, respectively. The chicken-based formula showed significantly better tolerance than an extensively hydrolyzed protein formula in the management of cow milk allergy in infants.

Calcitropic hormones and IGF-I are influenced by dietary protein

Elderly men and women with protein deficiencies have low levels of circulating IGF-I, and it is likely this contributes to reduced bone formation and increased bone resorption. We hypothesized that calcitropic hormones are involved in this effect and are affected by dietary protein. We therefore investigated the influence of a low-protein diet on the PTH-1,25-dihydroxyvitamin D3 [1,25(OH)₂D₃] axis and IGF-I in rats, using pamidronate to block resorption that normally contributes to mineral homeostasis. We fed 6-month-old Sprague Dawley female rats isocaloric diets containing 2.5% or 15% casein for 2 wk. Pamidronate was then administered sc (0.6 mg/kg/) for 5 d. Blood samples were collected at different time points. Serum 1,25(OH)₂D₃, IGF-I, PTH, calcium, and phosphorus were determined in all rats; vertebral bone strength and histomorphometric analysis were performed in rats subject to the longest low-protein diets. We found 2 wk of low protein increased PTH levels, decreased 1,25(OH)₂D₃, calcium, and IGF-I, suggesting that increased PTH compensates for low-protein-induced decreases in 1,25(OH)₂D₃. Pamidronate augmented the increased PTH after 8 wk of low protein and prevented the 1,25(OH)₂D₃ decrease. IGF-I remained low. Protein malnutrition induced decreases in relative bone volume and trabecular thickness, which was prevented by pamidronate. Maximal load was reduced by protein restriction, but rescued by pamidronate. In summary, the low protein diet resulted in hyperparathyroidism, a reduction in circulating levels of IGF-I, and reduced 1,25(OH)₂D₃ despite hyperparathyroidism. Blocking resorption resulted in further increases in PTH and improved microarchitecture and biomechanical properties, irrespective of vitamin D status or protein intake.

[Case report: allergy to cow's milk protein]

GOAL

Milk-based formulas can induce cow’s milk protein allergy (CMPA) in infants. This article discusses two cases of severe CMPA in infants exposed to casein-based formulas.

CASES

Case N°1: A 7 day old boy developed diarrhea with no improvement despite several courses of antibiotic and switching to formula without lactose. At 2 months of age he had a hemoglobin 8.6 mg/dL, IgE = 17.8 IU/ml (normal <1.5 UI/ml) and a CD4/CD8 ratio = 0.16 (normal 1.5 – 2.5). Upper endoscopy biopsies showed duodenal atrophy. He received a casein hydrolysate formula with decreased fecal flow but continued diarrhea. At 3 months of life he was changed to an amino acid formula with cessation of diarrhea in < 48 hours, resumption of normal growth and normalization of duodenal histology. Case N°2: A 10 month old boy had a 6-day history of vomiting, diarrhea and edema. His albumin was 2.35 mg/dL. An upper endoscopy biopsy showed severe duodenal atrophy. He received a casein hydrolysate with good tolerance and resolution of the edema. At 26 months of age, and endoscopic duodenal biopsy showed regeneration of the mucosa.

CONCLUSION

The CMPA is a frequent diagnosis in young infants that can be confused with infection. An early diagnosis is key to a positive outcome.

Dietary intervention in infancy and later signs of beta-cell autoimmunity

BACKGROUND

Early exposure to complex dietary proteins may increase the risk of beta-cell autoimmunity and type 1 diabetes in children with genetic susceptibility. We tested the hypothesis that supplementing breast milk with highly hydrolyzed milk formula would decrease the cumulative incidence of diabetes-associated autoantibodies in such children.

METHODS

In this double-blind, randomized trial, we assigned 230 infants with HLA-conferred susceptibility to type 1 diabetes and at least one family member with type 1 diabetes to receive either a casein hydrolysate formula or a conventional, cow's-milk-based formula (control) whenever breast milk was not available during the first 6 to 8 months of life. Autoantibodies to insulin, glutamic acid decarboxylase (GAD), the insulinoma-associated 2 molecule (IA-2), and zinc transporter 8 were analyzed with the use of radiobinding assays, and islet-cell antibodies were analyzed with the use of immunofluorescence, during a median observation period of 10 years (mean, 7.5). The children were monitored for incident type 1 diabetes until they were 10 years of age.

RESULTS

The unadjusted hazard ratio for positivity for one or more autoantibodies in the casein hydrolysate group, as compared with the control group, was 0.54 (95% confidence interval [CI], 0.29 to 0.95), and the hazard ratio adjusted for an observed difference in the duration of exposure to the study formula was 0.51 (95% CI, 0.28 to 0.91). The unadjusted hazard ratio for positivity for two or more autoantibodies was 0.52 (95% CI, 0.21 to 1.17), and the adjusted hazard ratio was 0.47 (95% CI, 0.19 to 1.07). The rate of reported adverse events was similar in the two groups.

CONCLUSIONS

Dietary intervention during infancy appears to have a long-lasting effect on markers of beta-cell autoimmunity--markers that may reflect an autoimmune process leading to type 1 diabetes. (ClinicalTrials.gov number, NCT00570102.).

[Comparative study of two enteral feeding formulas in hospitalized elders: casein versus soybean protein]

OBJECTIVES

To compare the incidence of gastrointestinal side effects of two enteral feeding formulas with changes in the origin of protein (casein and isolated soy protein) in hospitalised elderly patients.

METHOD

A cross sectional survey was done among a sample of elderly patients carrying nasogastric tube admitted to the Reina Sofia General Hospital (Murcia) during a period of 6 months. A formula based on casein or soybean protein was randomly assigned. The variables studied were: age, sex, cause for indication of EN, duration of the EN and maximum amount of EN administered per day. Nutritional status at admission and discharge, mortality and gastrointestinal side effects (diarrhoea, constipation, vomits or regurgitation) were also collected. Statistical analyses were performed with the Student's T and chi 2 tests, with a significance of 95%.

RESULTS

Sample conformed by 50 patients over 65 years (48% casein, 52% soybean) without statistically significant differences in age nor cause of indication of the EN. Either there were no differences in the nutritional status at the admission and discharge in both groups. Significant differences were observed in the incidence of diarrhoea (C: 45.83%, S: 7.69%, p = 0.009) and vomits (C: 41.66%, S: 15.38%, p = 0.05).

CONCLUSIONS

A significant reduction in the incidence of gastrointestinal complications, a reduction in the incidence of ulcers by pressure and less mortality occurred on the group that took formula based on the soybean protein. The individualized nutritional evaluation must be performed routinely when the patient is admitted to the hospital for detection and treatment of early signs of malnutrition.

Evaluation of an extensively hydrolysed casein formula (Damira 2000) in children with allergy to cow's milk proteins

OBJECTIVE

To assess the allergenic capacity of a new extensively hydrolysed casein formula (Damira 2000) in vivo in children with allergy to cow's milk, and to conduct an immunochemical evaluation of the product.

PATIENTS AND METHODS

The study comprised 67 children (1 month-7 years) with allergy to cow's milk proteins (ACMP). Skin testing was made with whole milk, milk formula for infants, the study hydrolysate and the milk fractions (alpha-lactoalbumin, beta-lactoglobulin and casein). Specific IgE against these allergens, and oral provocation test were also performed. Immunochemical evaluation of the product was carried out with gel filtration chromatography, 4-15% acrylamide gradient gel electrophoresis, specific IgE quantification versus the casein hydrolysate and a study of its allergenic potency.

RESULTS

The hydrolysate was tolerated by 66 of the 67 patients (98.5%) with ACMP. Biochemical analysis of the product confirmed the absence of traces of whole milk proteins. Specific IgE against the hydrolysate proved negative in all cases, and it was unable to inhibit FEIA even at concentrations 10 times greater than those used in the whole milk inhibition control. Likewise, no immunoblotting inhibition was recorded.

CONCLUSIONS

The new extensively hydrolysed casein product is safe and well tolerated by most children with ACMP. However, as with other extensive hydrolysates, some highly sensitised patients may present clinical manifestations. Controlled tolerance testing is therefore advised, under specialised medical supervision.

Acute effects of casein on postprandial lipemia and incretin responses in type 2 diabetic subjects

BACKGROUND AND AIMS

Exaggerated and prolonged postprandial lipemia is potentially atherogenic and associated with type 2 diabetes. Limited data exist regarding the influence of dietary protein on postprandial lipemia in type 2 diabetes. We investigated, over 8-h, the acute effects of casein alone or in combination with carbohydrate on postprandial lipid and incretin responses to a fat-rich meal in type 2 diabetes.

METHODS AND RESULTS

Eleven type 2 diabetic subjects ingested four test meals in random order: an energy-free soup plus 80 g of fat (control-meal); control-meal plus 45 g carbohydrates (CHO-meal); control-meal plus 45 g of casein (PRO-meal); and PRO-meal plus 45 g carbohydrates (CHO+PRO-meal). Triglyceride and retinyl palmitate responses were measured in plasma and in a chylomicron-rich and chylomicron-poor fraction. We found no significant differences in triglyceride responses to PRO- and CHO+PRO-meal compared to the control-meal. However, the addition of casein to the CHO-meal reduced the raised triglyceride response in the chylomicron-rich fraction. Retinyl palmitate responses did not differ significantly between meals in the chylomicron-rich fraction, whereas the PRO-meal increased retinyl palmitate in the chylomicron-poor fraction. PRO- and PRO+CHO-meal increased insulin and glucagon compared to the control-meal. PRO+CHO-meal increased the glucose-dependent insulinotropic peptide response while no change in glucagon-like peptide-1 responses was detected.

CONCLUSIONS

The data presented suggest that casein per se did not modulate the postprandial triglyceride response in type 2 diabetes. When added to carbohydrate, casein suppressed the triglyceride response in the chylomicron-rich fraction, increased insulin and glucagon but did not affect the incretin responses.

Type 1 diabetes, the A1 milk hypothesis and vitamin D deficiency

The 'A1' genetic variant of beta-casein in milk has been linked to type 1 diabetes (T1D). The keystone piece of supporting evidence is an ecological study positively correlating the incidence of T1D with amount of A1 beta-casein consumption per capita. Of relevance, A1 beta-casein consumption is also positively correlated with latitude, itself implicated in T1D through vitamin D deficiency. Ecological and biological evidence convincingly implicate vitamin D deficiency in T1D. Latitude is a confounder of the ecological data that underpin the hypothesis that A1 beta-casein in cow's milk is a causative factor in T1D.

Gluten- and casein-free diets for autistic spectrum disorder

BACKGROUND

It has been suggested that peptides from gluten and casein may have a role in the origins of autism and that the physiology and psychology of autism might be explained by excessive opioid activity linked to these peptides. Research has reported abnormal levels of peptides in the urine and cerebrospinal fluid of people with autism.

OBJECTIVES

To determine the efficacy of gluten and/or casein free diets as an intervention to improve behaviour, cognitive and social functioning in individuals with autism.

SEARCH STRATEGY

The following electronic databases were searched: CENTRAL(The Cochrane Library Issue 2, 2007), MEDLINE (1966 to April 2007), PsycINFO (1971 to April 2007), EMBASE (1974 to April 2007), CINAHL (1982 to April 2007), ERIC (1965 to 2007), LILACS (1982 to April 2007), and the National Research register 2007 (Issue1). Review bibliographies were also examined to identify potential trials.

SELECTION CRITERIA

All randomised controlled trials (RCT) involving programmes which eliminated gluten, casein or both gluten and casein from the diets of individuals diagnosed with an autistic spectrum disorder.

DATA COLLECTION AND ANALYSIS

Abstracts of studies identified in searches of electronic databases were assessed to determine inclusion by two independent authors The included trials did not share common outcome measures and therefore no meta-analysis was possible. Data are presented in narrative form.

MAIN RESULTS

Two small RCTs were identified (n = 35). No meta-analysis was possible. There were only three significant treatment effects in favour of the diet intervention: overall autistic traits, mean difference (MD) = -5.60 (95% CI -9.02 to -2.18), z = 3.21, p=0.001 (Knivsberg 2002) ; social isolation, MD = -3.20 (95% CI -5.20 to 1.20), z = 3.14, p = 0.002) and overall ability to communicate and interact, MD = 1.70 (95% CI 0.50 to 2.90), z = 2.77, p = 0.006) (Knivsberg 2003). In addition three outcomes showed no significant difference between the treatment and control group and we were unable to calculate mean differences for ten outcomes because the data were skewed. No outcomes were reported for disbenefits including harms.

AUTHORS' CONCLUSIONS

Research has shown of high rates of use of complementary and alternative therapies (CAM) for children with autism including gluten and/or casein exclusion diets. Current evidence for efficacy of these diets is poor. Large scale, good quality randomised controlled trials are needed.

Casein hydrolysate formula-induced liver dysfunction in a neonate with non-immunoglobulin E-mediated cow's milk allergy

A 10-day-old male neonate was admitted with bilious vomiting and gross hematochezia. Peripheral eosinophilia, delayed positive skin prick test to artificial milk, and elevated eosinophil cationic protein levels suggested cow's milk allergy. Fluid infusion with prohibition of oral intake improved the digestive symptoms. Breast-feeding was resumed on hospital day 3 and only casein hydrolysate formula was fed from day 7 onward. Nevertheless, eosinophilia and elevated transaminase levels developed on day 14. Liver dysfunction associated with casein hydrolysate formula was suspected and the infant was transferred to soy formula. Eosinophil counts decreased and transaminase levels were normalized on day 19. A cow's milk protein-specific lymphocyte proliferation test was positive for alpha-casein, beta-lactoglobulin, and bovine serum albumin, indicating sensitization of T cells to cow's milk proteins. These observations suggest that careful attention should be paid to liver dysfunction in non-immunoglobulin E-mediated cow's milk allergy, even when hypoallergenic formula is used.

Extensively hydrolyzed formula (MA-mi) induced exacerbation of food protein-induced enterocolitis syndrome (FPIES) in a male infant

BACKGROUND

Food protein-induced enterocolitis syndrome (FPIES) is a severe, cell-mediated food allergy in which digestive symptoms such as severe vomiting and diarrhea are induced by cow's milk and/or soy protein in infants. Generally, a food-specific IgE is not detected, and FPIES may be caused by inadvertent exposure to allergenic foods.

CASE SUMMARY

The patient in our case was a male infant in whom vomiting had been induced by ingestion of a cow's milk-based formula and bloody diarrhea had been caused by ingestion of breast milk during the neonatal period. Accidental ingestion of a new and extensively hydrolyzed casein/whey formula, MA-mi, caused watery diarrhea at 8 months of age, and FPIES was diagnosed based on these symptoms. In antigen-specific lymphocyte stimulation tests, New MA-1 was negative, but MA-mi and cow's milk antigens were positive. The only causative antigens were derived from cow's milk, and the symptoms were not induced by another extensively hydrolyzed casein formula, New MA-1. The patient grew and developed normally thereafter, and no symptoms were induced by solid food during the course of the condition.

DISCUSSION

MA-mi is likely to be used increasingly for allergic infants, but it is not necessarily a substitute for other hydrolyzed milk formulae in all cases, and care should be taken regarding its use and possible misuse.

Pancreatic Insulin Secretion in Rats Fed a Soy Protein High Fat Diet Depends on the Interaction between the Amino Acid Pattern and Isoflavones

Obesity is frequently associated with the consumption of high carbohydrate/fat diets leading to hyperinsulinemia. We have demonstrated that soy protein (SP) reduces hyperinsulinemia, but it is unclear by which mechanism. Thus, the purpose of the present work was to establish whether SP stimulates insulin secretion to a lower extent and/or reduces insulin resistance, and to understand its molecular mechanism of action in pancreatic islets of rats with diet-induced obesity. Long-term consumption of SP in a high fat (HF) diet significantly decreased serum glucose, free fatty acids, leptin, and the insulin:glucagon ratio compared with animals fed a casein HF diet. Hyperglycemic clamps indicated that SP stimulated insulin secretion to a lower extent despite HF consumption. Furthermore, there was lower pancreatic islet area and insulin, SREBP-1, PPARgamma, and GLUT-2 mRNA abundance in comparison with rats fed the casein HF diet. Euglycemic-hyperinsulinemic clamps showed that the SP diet prevented insulin resistance despite consumption of a HF diet. Incubation of pancreatic islets with isoflavones reduced insulin secretion and expression of PPARgamma. Addition of amino acids resembling the plasma concentration of rats fed casein stimulated insulin secretion; a response that was reduced by the presence of isoflavones, whereas the amino acid pattern resembling the plasma concentration of rats fed SP barely stimulated insulin release. Infusion of isoflavones during the hyperglycemic clamps did not stimulate insulin secretion. Therefore, isoflavones as well as the amino acid pattern seen after SP consumption stimulated insulin secretion to a lower extent, decreasing PPARgamma, GLUT-2, and SREBP-1 expression, and ameliorating hyperinsulinemia observed during obesity.

Diet and child behavior problems: fact or fiction?

Dietary treatment of children with behavioral disorders has had wide public appeal and been a source of controversy since the 1920's. Yet, to date, there is little empirical evidence supporting the effectiveness of dietary restrictions in treating child psychiatric disorders, in particular, autism and attention deficit hyperactivity disorder (ADHD). Thus, the purpose of this article is (a) to provide historical background information regarding dietary treatment in children with behavioral disorders, (b) review the evidence-based literature for common dietary interventions, (c) discuss limitations in the research, including challenges inherent in conducting well-controlled dietary studies, and (d) provide recommendations regarding how nurses in primary care settings can assist families in making informed decisions.

Soy compared to casein meal replacement shakes with energy-restricted diets for obese women: randomized controlled trial

Recent studies suggest that obese individuals lose weight more rapidly and lose more total weight with soy protein than with animal protein as a major diet component. The purpose of the present study was to evaluate the weight-loss efficacy and changes in body composition, waist circumference, blood pressure, and levels of plasma glucose, insulin, serum lipids, C-reactive protein, and homocysteine from consumption of either 3 soy shakes or 3 casein shakes daily as part of a 16-week, energy-restricted diet for obese women. Forty-three women with body mass index values of 30 to 40 kg/m(2) were randomized to intensive dietary interventions using either casein (n = 21) or soy (n = 22) shakes. Subjects were instructed to consume 3 shakes, 1 prepackaged entrée, and 5 servings of fruits or vegetables daily to achieve an energy intake of 4.5 to 5.0 MJ/d. Subjects attended classes weekly or biweekly. Weight, body fat, lipid, and glucose measurements were obtained at baseline and at 8 and 16 weeks. For both groups combined, subjects lost 8.1% of initial body weight (7.7 kg) at 8 weeks and 13.4% (12.7 kg) at 16 weeks. Weight loss from baseline did not differ significantly by group and, for completing subjects, was 14.0% +/- 1.2% (mean +/- SE) for casein and 12.8% +/- 1.4% for soy. With the intention-to-treat analysis, weight losses at 16 weeks were 12.5% +/- 1.4% for casein and 11.3% +/- 1.2% for soy. Body fat losses were 23.7% +/- 2.0% for casein and 21.8% +/- 2.4% for soy and did not differ significantly. Both study groups lost significant amounts of weight with a highly structured behavioral program incorporating 4 meal replacements and vegetables and fruits. Differences in weight loss and body composition changes between casein and soy treatments were not significant.

Bovine casein hydrolysate (c12 Peptide) reduces blood pressure in prehypertensive subjects

BACKGROUND

About one in four adults suffer from prehypertension. People with prehypertension are at risk of developing hypertension, being a biomarker for cardiovascular disease risk. The use of milk-derived protein hydrolysates containing peptides with angiotensin-converting enzyme (ACE) inhibiting properties may reduce blood pressure (BP) and thus the risk of developing hypertension.

METHODS

We investigated the BP-lowering effect of a casein-derived protein hydrolysate (C12 Peptide) during a 4-week intervention period in prehypertensive subjects. After a 2-week run-in period, 48 Taiwanese volunteers were randomly assigned to either placebo or C12 Peptide tablets for 4 weeks, followed by a 2-week off-treatment period. After the run-in period, BP was measured weekly.

RESULTS

Baseline values for systolic BP (mean +/- SEM) in the placebo and C12 Peptide groups were 137.1 +/- 3.1 and 137.9 +/- 2.4 mm Hg, respectively; those for diastolic BP were 85.2 +/- 2.1 and 86.9 +/- 2.0 mm Hg, respectively. Four weeks repeated daily intake of 3.8 g C12 Peptide reduced significantly systolic and diastolic BP by 10.7 +/- 1.6 mm Hg and 6.9 +/- 1.2 mm Hg, respectively, compared to baseline. Furthermore, plasma angiotensin II and aldosterone levels were reduced significantly (P < .05). The placebo group showed a BP reduction of 3.6 +/- 2.4 and 2.7 +/- 1.6 mm Hg in systolic and diastolic BP, respectively (P = not significant). No evidence of side effects was observed.

CONCLUSIONS

This study shows that C12 Peptide reduces BP in prehypertensive people.

Selenised casein protects against AOM-induced colon tumors in Sprague Dawley rats

Selenium (Se) has been shown to be protective against cancers in animal models at concentrations exceeding those considered essential for normal nutritional requirements. Organic forms of Se provided as dairy proteins were obtained from cows fed diets supplemented with yeast Se. The casein extracted from milk was found to contain approximately half the Se of the Se-enriched milk. This casein was included in a semi-purified AIN rodent diet so as to provide 1 ppm Se and 25% protein and was compared with AIN diets containing no added Se (control, 0.05 ppm), 1 ppm and 4 ppm Se as selenised yeast (Sel-Plex) Their influence on colon tumor expression was examined in rats induced with azoxymethane, the diets being introduced post-induction. The selenised casein diet at this concentration was effective in reducing colon tumor incidence (by 29%) and burden (decreased 52%, P < 0.05) relative to the control in rats 26 wk post-induction. Selenised yeast, when added at similar (1 ppm) and increased Se concentration (4 ppm), did not influence significantly colon tumor expression. However, in a second study, with Se yeast providing Se at 1 ppm, 4 ppm, and 8 ppm throughout the experiment, a significant reduction in tumors was observed with 8 ppm Se (colon tumor incidence was 15% lower and colon tumor burden was 35% lower, P < 0.05). However this was associated with a significantly lower body weight in the rats (down 10.5%, P < 0.05) indicating a possible disturbance with normal energy intake or metabolism. The form in which Se is presented in the diet may influence significantly its bioavailability and/or anticancer potential at given concentrations within a safe range. The efficacy of selenised casein and indeed other potential dietary sources deserve further investigation with regard to their ability to prevent colon tumors at concentrations considered safe in the diet.

Safety of intramyocardial injection of autologous bone marrow cells to treat myocardial ischemia in pigs

OBJECTIVE

The purpose of this study is to determine the potential adverse consequences of intracardiac injections of bone marrow mononuclear cells (BMCs) to facilitate the revascularization of ischemic myocardium.

BACKGROUND

Bone marrow mononuclear cells are used to treat heart failure, though there are few studies that evaluated the safety of BMC transplantation for chronic myocardial ischemia.

METHODS

The pigs received coronary ameroid constrictors to induce chronic myocardial ischemia and left ventricular dysfunction. At 4 weeks, autologous BMCs were injected intramyocardially by Boston Scientific Stiletto catheter with low-dose (10(7) cells) or high-dose BMC (10(8)). Control animals received saline. Blood samples were collected for hematological and chemical indices, including cardiac enzyme levels at regular time intervals postinfarction. At 7 weeks, animals underwent electrophysiological study to evaluate the arrhythmic potential of transplanted BMC, followed by necropsy and histopathology.

RESULTS

No mortalities were associated with intramyocardial delivery of BMC or saline. At Day 0, the total creatine phosphokinase (CPK) was in the normal range in all groups. All groups had significant elevations in CPK after ameroid placement, with no significant differences between groups. At 7 weeks, CPK in all groups had returned to pretreatment levels. Electrophysiological assessment revealed that one control animal had an inducible arrhythmia. No arrhythmias were induced in low- or high-dose BMC-treated pigs. There were no histopathological changes associated with BMC injection.

CONCLUSION

This study showed, in a clinically relevant large-animal model, that catheter-based intramyocardial injection of autologous BMC into ischemic myocardium is safe.

Autistic spectrum disorders 2: diagnosis and management

As many as six in every 1000 children may be affected by an autistic spectrum disorder. The previous article of this two-part series discussed the distinction between autism, Asperger's syndrome and pervasive developmental disorder, and examined the assessment process. This article looks at potential differential diagnoses that must be considered, as well as conditions associated with autism. Many theories about the causes of autism have been suggested, including the MMR vaccine. Recent research has suggested that there is no link between the vaccine and autism. There is no cure for autism, but intervention and management techniques should be aimed at educating parents and carers about the disorder and behavioural interventions to aid the child's skills development.

Lower consumption of cow milk protein A1 beta-casein at 2 years of age, rather than consumption among 11- to 14-year-old adolescents, may explain the lower incidence of type 1 diabetes in Iceland than in Scandinavia

AIM

To compare the consumption of the cow milk proteins A1 and B beta-casein among children and adolescents in Iceland and Scandinavia (Norway, Denmark, Sweden and Finland) as this might explain the lower incidence of type 1 diabetes (per 100,000/year, 0-14 years) in Iceland.

METHODS

The consumption of A1 beta-casein in each country among 2- and 11- to 14-year-old children was calculated from results on food intake and on cow milk protein concentration. The consumption values were then compared and evaluated against the incidence of type 1 diabetes.

RESULTS

There was a significant difference between the consumption of A1 (p = 0.034) as well as the sum of A1 and B (p = 0.021) beta-casein in Iceland and Scandinavia for 2-year-old children. In the same age group, consumption of A1 beta-casein correlated with the incidence of type 1 diabetes in the countries (r = 0.9; p = 0.037). No significant difference in consumption of A1 or the sum of A1 and B beta-casein was found for 11- to 14-year-old adolescents.

CONCLUSION

This study supports that lower consumption of A1 beta-casein might be related to the lower incidence of type 1 diabetes in Iceland than in Scandinavia. Additionally it indicates that consumption in young childhood might be of more importance for the development of the disease incidence than consumption in adolescence.

Health Implications of Milk Containing β-Casein with the A2Genetic Variant

Milk from dairy cows has long provided a high quality source of protein and selected micronutrients such as calcium to most populations. Recently, a relationship between disease risk and consumption of a specific bovine ss-casein fraction either A1 or A2 genetic variants has been identified. Populations, which consume milk containing high levels of ss-casein A2 variant, have a lower incidence of cardiovascular disease and type 1 diabetes. Furthermore, consumption of milk with the A2 variant may be associated with less severe symptoms of autism and schizophrenia. The mechanism of action focuses on ss-casein A1 and related forms preferentially that are able to produce a bioactive opioid peptide, ss-casomorphin-7 (ss-CM-7) during digestion. Infants may absorb ss-CM-7 due to an immature gastrointestinal tract. Adults, on the other hand, appear to reap the biological activity locally on the intestinal brush boarder. ss-CM-7 can potentially affect numerous opioid receptors in the nervous, endocrine, and immune systems. Whether there is a definite health benefit to milk containing the A2 genetic variant is unknown and requires further investigation.

Effect of Casein Hydrolysate, Prepared with Protease Derived from Aspergillus oryzae, on Subjects with High-Normal Blood Pressure or Mild Hypertension

Casein hydrolysate, prepared with Aspergillus oryzae protease, contains angiotensin I-converting enzyme inhibitory peptides, such as Val-Pro-Pro and Ile-Pro-Pro. We conducted a randomized, double-blind, placebo-controlled study to evaluate the effect of casein hydrolysate on the blood pressure of 144 subjects with high-normal blood pressure (n = 104) and mild hypertension (n = 40). Subjects were randomly assigned to two groups for a 12-week intake period. In the test group, both systolic (SBP) and diastolic (DBP) blood pressure decreased significantly compared with the placebo group: SBP/DBP significantly decreased from 138.2 +/- 6.5/84.4 +/- 5.3 mm Hg at week 0 to 132.3 +/- 7.3 (P < .001)/81.2 +/- 4.8 mm Hg (P < .001) at week 12. In the stratified analysis, the test product showed an antihypertensive effect in both the subject group with high-normal blood pressure and that with mild hypertension. No side effect was observed in any subjects in this study. These results demonstrate that the casein hydrolysate, prepared with A. oryzae protease, produced a significant reduction in blood pressure in a population of subjects with high-normal blood pressure or mild hypertension without an adverse event.

A Novel in vitro Microbial-Based Model for Studying Caries Formation – Development and Initial Testing

We report on the development and the initial testing of a new microbial-based caries model. Specimens were fixed on a rotating mount within a reaction chamber hermetically surrounded by a sterilised glove box. A cariogenic environment was obtained by inoculation with Streptococcus mutans (ATCC 25175) combined with a continuously repeating supply of sucrose solution, trypticase soy broth and artificial saliva applied by dripping. Twenty-five caries-free upper premolars were used. The mesial parts of the occlusal fissures had been sealed with a resin-based fissure sealant (test group 1). To produce marginal gaps, the distal parts had been moistened with saliva before resin application (test group 2). Five teeth served as control and were exposed to all fluids under sterile conditions before being removed from the system after 7 days. Test specimens were infected with S. mutans and were incubated for another 14 days. No unintentional contamination occurred during the 3-week period of operation. Demineralizations were evaluated by using confocal laser scanning microscopy. Only the test specimens showed clearly visible signs of biofilm formation and caries-like lesions. The mean primary lesion depth did not differ significantly between test groups. Wall lesion depths and surface areas of demineralizations underneath the fissure sealants were significantly higher in test group 2. Thus, our model allows the simultaneous production of primary and secondary caries-like enamel lesions in a considerable number of specimens and facilitates the possibility to manipulate and transfer them without necessarily terminating the experiment, opening new possibilities for in vitro caries research.

The A2 milk case: a critical review

This review outlines a hypothesis that A1 one of the common variants of beta-casein, a major protein in cows milk could facilitate the immunological processes that lead to type I diabetes (DM-I). It was subsequently suggested that A1 beta-casein may also be a risk factor for coronary heart disease (CHD), based on between-country correlations of CHD mortality with estimated national consumption of A1 beta-casein in a selected number of developed countries. A company, A2 Corporation was set up in New Zealand in the late 1990s to test cows and market milk in several countries with only the A2 variant of beta-casein, which appeared not to have the disadvantages of A1 beta-casein. The second part of this review is a critique of the A1/A2 hypothesis. For both DM-I and CHD, the between-country correlation method is shown to be unreliable and negated by recalculation with more countries and by prospective studies in individuals. The animal experiments with diabetes-prone rodents that supported the hypothesis about diabetes were not confirmed by larger, better standardised multicentre experiments. The single animal experiment supporting an A1 beta-casein and CHD link was small, short, in an unsuitable animal model and had other design weaknesses. The A1/A2 milk hypothesis was ingenious. If the scientific evidence had worked out it would have required huge adjustments in the world's dairy industries. This review concludes, however, that there is no convincing or even probable evidence that the A1 beta-casein of cow milk has any adverse effect in humans. This review has been independent of examination of evidence related to A1 and A2 milk by the Australian and New Zealand food standard and food safety authorities, which have not published the evidence they have examined and the analysis of it. They stated in 2003 that no relationship has been established between A1 or A2 milk and diabetes, CHD or other diseases.

IgE reactivity to vaccine components in dogs that developed immediate-type allergic reactions after vaccination

Allergic reactions after vaccination are considered as an important practical problem in dogs; however, their immunological mechanism has not been well understood. The present study was designed to investigate the relationship between IgE reactivity to the vaccines and immediate-type allergic reactions after vaccination in dogs. Sera from 10 dogs that developed immediate-type allergic reactions such as circulatory collapse, cyanosis, dyspnea, facial edema, and vomiting within 1h after vaccination with non-rabies monovalent or combined vaccines and sera from 50 dogs that did not develop allergic reactions after vaccination were collected. Serum IgE reactivity to the injected vaccines was measured by fluorometric ELISA using a mouse monoclonal anti-dog IgE antibody. Then, IgE reactivity to fetal calf serum (FCS) and stabilizer proteins (gelatin, casein, and peptone) included in the vaccines was measured in sera that had high levels of IgE to the vaccines. Levels of serum specific IgE to the vaccines in dogs with immediate-type allergic reactions (59-4173 fluorescence units [FU], mean +/- S.D.: 992.5 +/- 1181.9 FU) were significantly higher than those in control dogs (38-192 FU, 92.4 +/- 43.3 FU) (P < 0.001). Of the eight dogs that developed immediate-type allergic reactions and had high levels of serum specific IgE to the vaccines, seven had specific IgE directed to FCS. The IgE reactivity to the vaccines in sera from these dogs was almost completely inhibited by FCS. The other one dog had serum IgE directed to gelatin and casein included in the vaccine as stabilizers. The results obtained in this study suggest that immediate-type allergic reactions after vaccination in dogs were induced by type I hypersensitivity mediated by IgE directed to vaccine components. In addition, FCS, gelatin, and casein included in vaccines could be the causative allergens that induced immediate-type allergic reactions after vaccination in dogs.

Food protein-induced enterocolitis syndrome: case presentations and management lessons

Enterocolitis induced in infants by cow's milk and/or soy protein has been recognized for decades. Symptoms typically begin in the first month of life in association with failure to thrive and may progress to acidemia and shock. Symptoms resolve after the causal protein is removed from the diet but recur with a characteristic symptom pattern on re-exposure. Approximately 2 hours after reintroduction of the protein, vomiting ensues, followed by an elevation of the peripheral blood polymorphonuclear leukocyte count, diarrhea, and possibly lethargy and hypotension. The disorder is generally not associated with detectable food-specific IgE antibody. There are increasing reports of additional causal foods, prolonged clinical courses, and onset outside of early infancy, leading to description of a food protein-induced enterocolitis syndrome. The disorder poses numerous diagnostic and therapeutic challenges. The purpose of this report is to delineate the characteristic clinical features and review the possible pathophysiologic basis to frame a rational strategy toward management.

Selective allergy to sheep's and goat's milk proteins

BACKGROUND

Cow's milk proteins are amongst the most common causes of food allergy in infants, and caseins are probably the main allergens. The existence of a high degree of cross-reactivity between milk caseins from different animals has been reported. We describe a 2-year-old boy who experienced allergic reactions after eating and touching sheep's cheese, but who tolerated cow's milk and cow's milk dairy products. He had never ingested milk or milk derivatives from sheep or goat.

METHODS

Skin prick tests were carried out using whey fractions of cow's milk, whole milk and casein from goat, sheep and cow. We also performed skin prick tests with enzymes used in cheese production. Prick-by-prick tests with cheese made from cow, sheep and goat and their corresponding whole milk were also performed. Total serum IgE and specific IgE to cow's milk proteins, whole cow's milk and sheep's milk were determined. Specific IgE against casein and whole milk from the three different species were determined by ELISA. Inhibition of IgE binding to bovine casein was tested for casein and whole milk from all three species. The proteins of three types of casein and whole milk from cow, sheep and goat were separated by SDS-PAGE and were incubated with the patient's serum.

RESULTS

Skin tests were positive to sheep's milk and goat and sheep casein and were negative to all cow's milk proteins and whole cow's and goat's milk. Prick-by-prick tests were positive to goat's and sheep's cheese and were negative to cow's cheese. In ELISA-inhibition, sheep's milk and goat and sheep casein were able to inhibit > 50 % of specific IgE binding to sheep casein. The results of immunoblotting showed that the patient's circulating IgEs recognized only one band in the lanes corresponding to sheep and goat casein.

CONCLUSIONS

We report a patient with allergy to sheep's and goat's milk proteins but not to cow's milk proteins. Sheep casein was probably the main allergen causing sensitization in this patient. The results suggest that sheep casein shows a high degree of cross-reactivity with goat casein but not with cow casein. Our patient presented allergic symptoms caused by sheep and goat milk and cheese proteins. However, he was able to tolerate cow's milk and cow's milk dairy products without any ill effects.

Gluten- and casein-free diets for autistic spectrum disorder

BACKGROUND

It has been suggested that peptides from gluten and casein may have a role in the origins of autism and that the physiology and psychology of autism might be explained by excessive opioid activity linked to these peptides. Research has reported abnormal levels of peptides in the urine and cerebrospinal fluid of persons with autism. If this is the case, diets free of gluten and /or casein should reduce the symptoms associated with autism.

OBJECTIVES

To determine the efficacy of gluten- and/or casein- free diets as an intervention to improve behaviour, cognitive and social functioning in individuals with autism.

SEARCH STRATEGY

Electronic searching of abstracts from the Cochrane Library (Issue 3, 2003), PsycINFO (1971- May 2003), EMBASE (1974- May 2003), CINAHL (1982- May 2003), MEDLINE (1986- May 2003), ERIC (1965-2003), LILACS (to 2003) and the specialist register of the Cochrane Complementary Medicine Field (January 2004). Review bibliographies were also examined to identify potential trials.

SELECTION CRITERIA

All randomised controlled trials involving programmes which eliminated gluten, casein or both gluten and casein from the diets of individuals diagnosed with autistic spectrum disorder.

DATA COLLECTION AND ANALYSIS

Abstracts of studies identified in searches of electronic databases were read and assessed to determine whether they might meet the inclusion criteria. The authors independently selected the relevant studies from the reports identified in this way. As only one trial fitted the inclusion criteria, no meta-analysis is currently possible and data are presented in narrative form.

MAIN RESULTS

The one trial included reported results on four outcomes. Unsurprisingly in such a small-scale study, the results for three of these outcomes (cognitive skills, linguistic ability and motor ability) had wide confidence intervals that spanned the line of nil effect. However, the fourth outcome, reduction in autistic traits, reported a significant beneficial treatment effect for the combined gluten- and casein- free diet.

REVIEWERS' CONCLUSIONS

This is an important area of investigation and large scale, good quality randomised controlled trials are needed.

Dermatological powder as hidden cause of occupational allergy due to casein: a case report

We report a case of occupational asthma due to hidden casein, contained in a dermatological powder. A 44 year old nurse reported the recent onset of rhinitis and asthma, clearly related to the work environment. Skin tests for food allergens revealed a positivity for milk proteins. The source of dispersed milk proteins in the work environment was found to be a dermatological formulation of an inert refreshing powder, used to treat excoriated areas in the elderly. Skin prick tests confirmed the positivity to casein and to the commercial product.

Cow's milk allergic patients should be informed of the sources of caseinate

Cow's milk allergy is one of the most common food allergies prevalent during infancy and it may cause anaphylactic reactions in more sensitive patients. Cow's milk is found in a large variety of processed foods but its presence may be hidden as it is occasionally listed on the product label in an manner unrecognizable to the consumer. The parents of more sensitive patients need to be instructed in the detection of these potential sources of hidden cow's milk by judiciously reading food labels and in recognition of the sources, thus avoiding possible untoward reactions. We report a patient with cow's milk allergy who had an anaphylactic reaction following the ingestion of a hot dog product that contained caseinate. The label of the ingested hot dog product listed only the code number of caseinate. Avoidance of such occurrences would be more likely if firstly food products were labeled more accurately and secondly if physicians were to instruct their patients more thoroughly about their allergies, including the relevant names of all allergens.