Skipping Breakfast Is Associated with an Atherogenic Lipid Profile in Overweight and Obese Prepubertal Children.

BACKGROUND: Skipping breakfast has been associated with a higher risk of obesity and cardiovascular (CV) risk factors. However, it is not known if skipping breakfast is also correlated with CV risk factors independently from obesity. The mechanisms explaining the role of skipping breakfast on promoting fat accumulation as well as CV risk are not known. Hormones, in particular, insulin-like growth factor-1 (IGF-1), may potentially play a role in the metabolic profile of breakfast skippers. AIM: This cross-sectional study aims to test, in a sample of overweight/obese children, the hypotheses that skipping breakfast is associated with a worse metabolic profile and that IGF-1 levels are associated with this unfavorable metabolic profile. METHODS AND RESULTS: We enrolled 112 overweight/obese prepubertal children (3-12 years). Anthropometric characteristics (height SDS, weight SDS, and body mass index (BMI) z-score) were measured. Blood samples were collected to evaluate glucose and lipid metabolisms and hormone profile (growth hormone (GH), IGF-1, insulin, and cortisol). The triglycerides/high-density lipoprotein (HDL) cholesterol ratio was calculated as a predictor of cardiovascular risk. Children were divided into two groups according to breakfast habits: consumers (≥5 weekly; N = 76) and skippers (≤4 weekly; N = 36). Glycaemia, total and low-density lipoprotein (LDL) cholesterol, triglycerides (p < 0.05), and triglycerides/HDL cholesterol ratio (p < 0.001) were higher, while HDL cholesterol was lower (p < 0.01) in skippers as compared to consumers. IGF-1 concentrations were inversely correlated with LDL cholesterol (r = -0.279, p=0.013) and directly correlated with HDL cholesterol (r = 0.226, p=0.047). IGF-1 correlated positively with HDL cholesterol (r = 0.266, p=0.045) in consumers and correlated negatively with LDL cholesterol (r = -0.442, p=0.024) in skippers. Breakfast consumption among prepubertal overweight/obese children showed a better lipid profile in comparison with those who skipped breakfast [OR: 0.165 (95% CI: 0.053-0.518), p=0.001]; these latter odds of the increased triglycerides/HDL cholesterol ratio was 6.1-fold higher. CONCLUSIONS: Breakfast skippers show a worse lipid profile when compared to breakfast consumers. IGF-1 might play a role as an independent modulator of lipid metabolism.

Efficacy of ketogenic diet for infantile spasms: A systematic review.

The aim of this systematic review was to collect and analyze all the RCTs and observational studies investigating the efficacy of ketogenic diet (KD) in infantile spasms (IS) patients after a 1- to 6-month follow-up period, in terms of decrease in seizure frequency of >50% or a seizure-free interval. Moreover, the potential effect of gender, IS etiology, age at onset of IS, and age at start of KD have been investigated. Finally, we evaluated the seizure-free rate at 12 and 24 months of follow-up. In June 2016, a computer search was performed on MedLine (PubMed), EMBASE, and the Cochrane Library. Only, English language studies conducted after 1980 and those reporting in detail the variation in seizure frequency have been selected. Thirteen observational studies (341 patients) were included in the final analysis. A median rate of 64.7% of patients experienced a spasm reduction >50% (IQR: 38.94%). The median spasm-free rate was 34.61% (IQR: 37.94%). IS of unknown etiology seemed to have an increased probability of achieving freedom from seizures (RR: 1.72, 95%CI: 1.18-2.53). Long-time follow-up data revealed a median seizure-free rate of 9.54% (IQR: 18.23%). Although the literature is still lacking in high-quality studies, which could provide a stronger level evidence, our findings suggest a potential benefit of KD for drug-resistant IS patients.

Role of the C1858T polymorphism of protein tyrosine phosphatase non-receptor type 22 (PTPN22) in children and adolescents with type 1 diabetes.

In recent years, increasing interest has been devoted to the susceptibility gene polymorphisms in type 1 diabetes (T1D) as well as in other autoimmune diseases. Among these, a nucleotide polymorphism of the gene encoding for the protein tyrosine phosphatase non-receptor type 22 (PTPN22) has been associated with T1D in several studies. The aim of this study is to define the frequency of the C1858T polymorphism in the PTPN22 gene in a cohort of 113 Caucasian patients (58 males and 55 females) with T1D, and to assess a possible correlation with a group of clinically relevant variables: age at onset, gender, diabetes-related autoantibodies, residual ß-cell function and daily insulin requirement (IR) 6 months after diagnosis. Using a PCR-RFLP approach, we evidenced a 17.7% frequency of the PTPN22 C1858T polymorphism in diabetic patients, higher than the frequency showed in the general population. A statistically significant correlation between this polymorphism and higher levels of C-peptide at diagnosis and lower IR at 6 months from diagnosis was observed (P=0.001 and P=0.04). Moreover, 1858T variant carriers were more frequently positive for glutamic acid decarboxylase (GAD) autoantibodies at diagnosis than wild-type subjects (P=0.19). On the other hand, no significant difference regarding age at onset, gender distribution, insulinoma-associated 2 molecule (IA2) and islet cell antibodies (ICA) positivity was found. These findings, if adequately confirmed in the future and extended to larger samples, may characterize a subset of T1D patients with a defined genetic pattern, who may be eligible for trials aimed to preserve residual ß-cell function in the coming years.

Neuropsychological impairment in childhood absence epilepsy: Review of the literature.

AIM: Childhood absence epilepsy (CAE) is a paediatric epilepsy syndrome characterized by typical absence seizures in school age children. Although it is commonly considered to have a good prognosis, with a good response to antiepileptic drugs, recent studies questioned this traditional view of a "benign" disorder, in particular regarding neuropsychological functioning. The aim of this study is to review the neuropsychological involvement in patients affected by CAE. METHODS: A literature search was carried out in PubMed's and Medline's databases for all relevant studies published between 1924 and 2014. The keywords used were neuropsychology, absence seizures, and CAE. Specific review articles, systematic reviews, textbooks and case reports were examined for any further publications. RESULTS: In intellectual functioning, CAE patients seem to perform worse than healthy children, even if their IQ scores fall within the normal range. Similarly, CAE seems to affect verbal skills and learning. Executive functions have been reported to be mildly impaired. Data regarding memory are still conflicting. DISCUSSION: Given the neuropsychological deficits in many CAE patients which significantly affect their quality of life, CAE should not be considered entirely "benign". An early identification of neuropsychological dysfunction in CAE children is essential for appropriate treatment.

The oxoglutarate/malate carrier of rat brain mitochondria operates by a uniport exchange mechanism.

Here, the oxoglutarate carrier, already isolated from various sources and described in the literature, has been purified from rat brain and reconstituted in proteoliposomes for an accurate kinetic study. The rate of uptake of labelled oxoglutarate and malate has been measured in various conditions, essentially in double substrate experiments. The data so obtained fit the hypothesis that the carrier operates by a uniport-exchange mechanism and provide significant values for the kinetic constants and the equilibrium constants implied in the process. Their analysis leads to the conclusion that the carrier is maximally efficient in the exchange between external malate and internal oxoglutarate, as required by the malate/aspartate shuttle, which should be the main role of the oxoglutarate carrier in brain mitochondria.

A micro-batchwise technique method for rapid reconstitution of functionally active mitochondrial ADP/ATP carrier from Jerusalem artichoke (Helianthus tuberosus L.) tubers.

A method for rapid reconstitution of ADP/ATP carrier from Jerusalem artichoke (Helianthus tuberosus L.) tubers mitochondria in proteoliposomes is described. The method is based on the well known property of the Amberlite resin to absorb the detergent allowing proteoliposome formation. This has been achieved by a micro-batchwise technique, using a rotating plate stirrer. An evaluation of the optimal conditions, in comparison with the more usual column method is presented. The purified ADP/ATP carrier, incorporated in proteoliposomes by this method, shows a high transport activity and a higher specific activity with respect to proteoliposomes obtained by the column procedure. Furthermore the proteoliposomal preparations are more homogeneous in size, with a diameter ranging from 300 to 350 nm. The method is suitable for the reconstitution of other membrane transport proteins.

Kinetic evidence for the uniport mechanism hypothesis in the mitochondrial tricarboxylate transport system.

The kinetics of the transport of citrate by the tricarboxylate transport system located in the inner mitochondrial membrane was studied in proteoliposomes containing the purified carrier protein, in order to verify the previously hypothesized mechanism of uniport (J. Bioenerg. Biomembr. 35, 133-140, 2003) and achieve some information on the kinetic properties of the carrier transport system. For this purpose, a mathematical model has been elaborated and the experimental data were analyzed according to it. The results indicate that the data actually fit with the uniport model, and hence it is confirmed that the carrier has a single binding site for its substrates and can oscillate between the inside and outside form, in both the free and substrate-bound states. The rearrangement of the free form is slower than the bound form in both directions. The dissociation constants for the internal substrate are at least one order of magnitude higher than the one for external citrate. As a consequence of these last two points, the rate of citrate transport by the carrier is much higher when it operates in exchange with another substrate than when it operates in net uniport.

Citrate uniport by the mitochondrial tricarboxylate carrier: a basis for a new hypothesis for the transport mechanism.

The tricarboxylate transport system located in the inner mitochondrial membrane was studied as an isolated protein reconstituted in proteoliposomes. The effects on the transport of citrate by various reagents, specific for different aminoacid residues, were analyzed. In the group of SH reagents, it was found that N-ethylmaleimide is an irreversible inhibitor of the citrate-citrate exchange, while HgCl2 and the mercurial mersalyl cause a rapid unidirectional efflux of citrate from liposomes. It was demonstrated that NEM and mercurials act on different SH groups. Dithioerythritol is not able to reverse the effect of mersalyl unless another reagent, pyridoxalphosphate, is present. Pyridoxalphosphate itself, a reagent specific for NH2 residues, is an effective inhibitor of citrate exchange transport, as measured in both influx and efflux, but it has no effect on the mercurial-induced efflux. The same behavior was observed with diethylpyrocarbonate, a reagent specific for histidine and tyrosine residues. Interestingly, a slow basic efflux of internal citrate, in the absence of countersubstrate, was observed in proteoliposomes. Because it is inhibited by the same reagents acting on the exchange process, it is deduced that it is catalyzed by the tricarboxylate carrier. The ability of the carrier to perform a uniport of the substrate suggests the presence of a single substrate binding site on the carrier protein. A preliminary kinetic approach indicates that such a transport model is compatible with this theory.

Acute abdomen in a 15-year-old patient with Peutz-Jeghers syndrome. Surgical approach.

The natural history of Peutz-Jeghers syndrome (PJS) is characterized by gastrointestinal complications (occlusion, invagination or bleeding), often the first clinical manifestation in young patients. Surgical treatment consists of treating the complication, exploring the bowel and cleaning out all polyps to prevent further emergency operations at brief intervals. For this purpose both the laparotomic and laparoscopic approaches have been proposed, especially in young patients. A 15-year-old girl was admitted for investigation of colicky abdominal pains. When she was 5 years old, PJS was diagnosed. On admission to our department, the patient underwent emergency esophagogastroduodenoscopy and colonoscopy, both negative. At 24 hours after admission peritonitis developed. Given her clinical history, we rejected the laparoscopic approach proposed at admission and decided for an open laparotomy. Laparotomy disclosed a long jejunoileal invagination that caused irreversible ischemic damage of the bowel. We resected about 130 cm of the ileum and did an end-to-end ileo-ileal anastomosis. Meticulous palpation and transillumination of the residual bowel identified no other polyps. In young patients with acute abdomen and with proven or suspected PJS instead of laparoscopy, open laparotomy is a unique occasion to explore the residual bowel thoroughly, manually and, if possible, endoscopically.

The kinetic mechanism of the glutamate-aspartate carrier in rat intestinal brush-border membrane vesicles: the role of potassium.

The sodium dependent transport system for L-glutamate and L-aspartate localized in the apical part of rat enterocytes has previously been kinetically characterized (Prezioso, G., and Scalera, V. (1996). Biochim. Biophys. Acta 1279, 144-148). In this paper the mechanism by which the potassium cation specifically activates the L-glutamate-sodium cotransport process is investigated. Potassium has been found to act as an activator when it is present inside the membrane vesicles, while its presence outside is ineffective, and the effect is saturable. The kinetic parameters with respect to sodium and glutamate have been compared in the presence and in the absence of the activator. The results indicate that the ordered sodium-sodium glutamate mechanism is not altered by potassium, and that the activation is probably exerted on both the rate determining steps of the transport process. It is proposed that (1) a specific binding site for potassium is present on the inside hydrophilic part of the membrane carrier, (2) the binding of the effector accelerates the intramembrane rearrangement steps of both the disodium glutamate-carrier complex and the free carrier, (3) the affinity of the carrier is lowered with respect to sodium whereas it is increased for glutamate, and (4) K+ antiport is not performed by this carrier.

Genomic organization and mapping of the gene (SLC25A19) encoding the human mitochondrial deoxynucleotide carrier (DNC).

The deoxynucleotide carrier (DNC) transports deoxynucleotides into mitochondria and is therefore essential for mtDNA synthesis. The human DNC gene (SLC25A19) spans about 16.5 kb and consists of nine exons with the translation start site in exon 4. It is located on chromosome 17q25.3. Three transcripts, which differ in their 5' ends and are generated by alternative splicing, have been identified.

[Treatment of desmoid tumors of the mesenteric root]. / Traitements des tumeurs desmoïdes de la racine du mésentère.

OBJECTIVE: To elaborate a therapeutic scheme for desmoid tumors developing within the mesenteric root. These uncommon and often unrecognized tumors are difficult to treat as they lie very close to the superior mesenteric vessels. PATIENTS AND METHODS: Retrospective analysis of 14 cases treated in our center over the last 20 years and a review of the literature. RESULTS: The analysis led to the development of a therapeutic scheme. Patients are placed under regular surveillance to detect any progression of the mesenteric root desmoid tumor. In case of progression, surgery should be proposed as often as possible in spite of the real difficulty of this surgery. When the tumor is unresectable, hormone therapy, sulindac, chemotherapy and radiotherapy can be proposed as appropriate. CONCLUSION: Based on the available literature, the proposed decisional tree is a helpful management tool. This scheme should be validated with the help of a National Observatory focusing on this rare disease.

Sequential ordered mechanism for the sodium-glutamate transport in intestinal brush border membrane vesicles.

The glutamate/aspartate carrier localized in the brush-border membrane vesicles from enterocytes is known as a transport system catalyzing a sodium-substrate cotransport driven by the sodium gradient across the membrane. The kinetics of this transport system is studied by analogy with an enzymatic bi-substrate reaction. The results of this approach can be summarized as follows: (1) The dependence of the L-glutamate transport rate on the sodium concentration is sigmoidal, and the stoichiometry of the transport is 2 Na+/1 glutamate/1 carrier molecule. (2) The mechanism is sequential ordered, with L-glutamate binding after both the sodium cations. In addition, there is a very high degree of cooperativity between the two sodium binding sites.

Kinetic characterization of the reconstituted dicarboxylate carrier from mitochondria: a four-binding-site sequential transport system.

The mitochondrial antiport carriers form a protein family with respect to their structure and function. The kinetic antiport mechanism, being of the sequential type, shows that the dicarboxylate carrier also belongs to this family. This was demonstrated by bireactant initial velocity studies of the purified and reconstituted carrier protein. The transport affinity of the carrier for the internal substrate was largely independent of the external substrate concentration and vice versa, whereas the carrier's apparent Vmax rose with increasing saturation of internal and external binding sites. Thus, the carrier forms a catalytic ternary complex with one internal and one external substrate molecule. As compared to other mitochondrial antiport carriers, however, the situation with the dicarboxylate carrier is more complex. On each membrane side of the protein two separate binding sites exist, one specific for phosphate (or its analogue phenyl phosphate), the other specific for dicarboxylate (or butyl malonate), that can be occupied by the respective substrates without mutual interference. This became evident from the non-competitive interaction of these substrates (or analogues) with the carrier. The two external, but not the two internal binding sites could be saturated simultaneously with phosphate and malate, thereby causing inhibition of transport. All four binding sites must be associated with the same translocation pathway through the carrier protein, since the sequential antiport mechanism held true for the phosphate/malate heteroexchange as well as for the malate/malate or phosphate/phosphate homoexchange.

Peptide-specific antibodies and proteases as probes of the transmembrane topology of the bovine heart mitochondrial porin.

We have investigated the transmembrane topology of the bovine heart mitochondrial porin by means of proteases and antibodies raised against the amino-terminal region of the protein. The antisera against the human N-terminus reacted with porin in Western blots of NaDodSO4-solubilized bovine heart mitochondria and with the membrane-bound porin in enzyme-linked immunosorbent assay (ELISA). The immunoreaction with mitochondria coated on microtiter wells showed that the amino-terminal region of the protein is not embedded in the lipid bilayer but is exposed to the cytosol. Back-titration of unreacted anti-N-terminal antibodies after their incubation with intact mitochondria demonstrated that the porin N-terminus is also exposed in "noncoated" mitochondria. No difference in antisera reactivity was observed between intact and broken mitochondria. Intact and broken mitochondria were subjected to proteolysis by specific proteases. The membrane-bound bovine heart porin was strongly resistant to proteolysis, but a few specific cleavage sites were observed. Staphylococcus aureus V8 protease gave a large 24K N-terminal peptide, trypsin produced a 12K N-terminal and an 18K C-terminal peptide, and chymotrypsin gave two peptides of Mr 19.5K and 12.5K, which were both recognized by the antiserum against the human N-terminus. Carboxypeptidase A was ineffective in cleaving the membrane-bound porin in both intact and broken mitochondria. Thus, the carboxy-terminal part of the protein is probably not exposed to the water phase. The cleavage patterns of membrane-bound porin, obtained with S. aureus V8 protease, trypsin, and chymotrypsin, showed no difference between intact and broken mitochondria, thus indicating that all porin molecules have the same orientation in the membrane. The computer analysis of the sequence of human B-lymphocyte porin suggested that 16 beta-strands can span the phospholipid bilayer. This result, together with the overall information presented, allowed us to draw a possible scheme of the transmembrane arrangement of mammalian mitochondrial porin.

Kinetic characterization of the reconstituted carnitine carrier from rat liver mitochondria.

The carnitine carrier was purified from rat liver mitochondria and reconstituted into liposomes by removing the detergent from mixed micelles by Amberlite. Optimal transport activity was obtained with 1 microgram/ml and 12.5 mg/ml of protein and phospholipid concentration, respectively, with a Triton X-100/phospholipid ratio of 1.8 and with 16 passages through the same Amberlite column. The activity of the carrier was influenced by the phospholipid composition of the liposomes, being increased in the presence of cardiolipin and decreased in the presence of phosphatidylinositol. In the reconstituted system the incorporated carnitine carrier catalyzed a carnitine/carnitine exchange which followed a first-order reaction. The maximum transport rate of external [3H]carnitine was 1.7 mmol/min per g protein at 25 degrees C and was independent of the type of countersubstrate. The half-saturation constant (Km) for carnitine was 0.51 mM. The affinity of the carrier for acylcarnitines was in the microM range and depended on the carbon chain length. The activation energy of the carnitine/carnitine exchange was 133 kJ/mol. The carrier function was independent of the pH in the range between 6 and 8 and was inhibited at pH below 6.

myo-inositol transport in rat intestinal brush border membrane vesicles, and its inhibition by D-glucose.

The uptake of myo-inositol into rat intestinal brush border membrane vesicles (BBMV) has been investigated. It is demonstrated that myo-inositol is transported into the vesicles by a secondary active process, specifically using the sodium gradient as the driving force. In the absence of sodium gradient, the transport reaction is still sodium dependent, and rheogenic, indicating that a myo-inositol/sodium cotransport is likely to occur. A kinetic analysis shows an hyperbolic saturation process with a Km of 0.16 +/- 0.02 mM with respect to myo-inositol and Vmax of 68.5 +/- 21.2 pmol/min per mg protein. The transport is inhibited by D-glucose, phloridzin and few other sugars. The mechanism of D-glucose inhibition appears to be of the mixed type. Finally, the myo-inositol transport is trans-activated by myo-inositol itself, but not by D-glucose. It is concluded that myo-inositol is transported into rat intestine BBMV by a specific transport system, which is also able to bind D-glucose, but not efficiently transport it across the membrane.

Kinetic characterization of the reconstituted tricarboxylate carrier from rat liver mitochondria.

The tricarboxylate carrier from rat liver mitochondria was purified by chromatography on hydroxyapatite/celite and reconstituted in phospholipid vesicles by removing the detergent using hydrophobic chromatography on Amberlite. Optimal transport activity was obtained by using a Triton X-114/phospholipid ratio of 0.8, 6% cardiolipin and 24 passages through a single Amberlite column. In the reconstituted system the incorporated tricarboxylate carrier catalyzed a first-order reaction of citrate/citrate or citrate/malate exchange. The activation energy of the exchange reaction was 70.1 kJ/mol. The rate of the exchange had a pH optimum between 7 and 8. The half-saturation constant was 0.13 mM for citrate and 0.76 mM for malate. All these properties were similar to those described for the tricarboxylate transport system in intact mitochondria. In proteoliposomes the maximum exchange rate at 25 degrees C reached 2000 mumols/min per g protein. This value was independent of the type of substrate present at the external or internal space of the liposomes (citrate or malate).

A simple and rapid method for the purification of the mitochondrial porin from mammalian tissues.

A new, simple and rapid procedure for the purification of high amounts of mitochondrial porins from different tissues of mammalia is described. The method consists in a single step hydroxyapatite/celite chromatography of Triton X-100 solubilized mitochondrial membranes. For optimal purification several factors are critical such as the absence of salts, a low protein/detergent ratio and an exact hydroxyapatite/celite ratio of 2:1.