A common X-linked inborn error of carnitine biosynthesis may be a risk factor for nondysmorphic autism

We recently reported a deletion of exon 2 of the trimethyllysine hydroxylase epsilon (TMLHE) gene in a proband with autism. TMLHE maps to the X chromosome and encodes the first enzyme in carnitine biosynthesis, 6-N-trimethyllysine dioxygenase. Deletion of exon 2 of TMLHE causes enzyme deficiency, resulting in increased substrate concentration (6-N-trimethyllysine) and decreased product levels (3-hydroxy-6-N-trimethyllysine and γ-butyrobetaine) in plasma and urine. TMLHE deficiency is common in control males (24 in 8,787 or 1 in 366) and was not significantly increased in frequency in probands from simplex autism families (9 in 2,904 or 1 in 323). However, it was 2.82-fold more frequent in probands from male-male multiplex autism families compared with controls (7 in 909 or 1 in 130; P = 0.023). Additionally, six of seven autistic male siblings of probands in male-male multiplex families had the deletion, suggesting that TMLHE deficiency is a risk factor for autism (metaanalysis Z-score = 2.90 and P = 0.0037), although with low penetrance (2-4%). These data suggest that dysregulation of carnitine metabolism may be important in nondysmorphic autism; that abnormalities of carnitine intake, loss, transport, or synthesis may be important in a larger fraction of nondysmorphic autism cases; and that the carnitine pathway may provide a novel target for therapy or prevention of autism.     

Short term serum pharmacokinetics of diammine silver fluoride after oral application

Background

There is growing interest in the use of diammine silver fluoride (DSF) as a topical agent to treat dentin hypersensitivity and dental caries as gauged by increasing published research from many parts of the world. While DSF has been available in various formulations for many years, most of its pharmacokinetic aspects within the therapeutic concentration range have never been fully characterized.

Methods

This preliminary study determined the applied doses (3 teeth treated), maximum serum concentrations, and time to maximum serum concentration for fluoride and silver in 6 adults over 4 h. Fluoride was determined using the indirect diffusion method with a fluoride selective electrode, and silver was determined using inductively coupled plasma-mass spectrometry. The mean amount of DSF solution applied to the 3 teeth was 7.57 mg (6.04 μL).

Results

Over the 4 hour observation period, the mean maximum serum concentrations were 1.86 μmol/L for fluoride and 206 nmol/L for silver. These maximums were reached 3.0 h and 2.5 h for fluoride and silver, respectively.

Conclusions

Fluoride exposure was below the U.S. Environmental Protection Agency (EPA) oral reference dose. Silver exposure exceeded the EPA oral reference dose for cumulative daily exposure over a lifetime, but for occasional use was well below concentrations associated with toxicity. This preliminary study suggests that serum concentrations of fluoride and silver after topical application of DSF should pose little toxicity risk when used in adults.

Clinical trials registration

NCT01664871.

     

Beyond average: potential for measurement of short telomeres

The length of telomeres, and in particular the abundance of short telomeres, has been proposed as a biomarker of aging and of general health status. A wide variety of studies show the association of short telomeres with age related pathologies and cancer, as well as with lifespan and mortality. These facts highlight the importance of measuring telomere length in human populations and by using reliable methods to uncover the association between telomere length and human disease. This review discusses the advantages and drawbacks of current telomere length measurement methods. Most of these methods provide mean telomere length values per cell or per sample and very few of them are able to measure the abundance of short telomeres, which are the ones indicative of telomere dysfunction. The information provided by each method and their suitability for different studies is discussed here.     

Temporal relationship of serum markers and tissue damage during acute intestinal ischemia/reperfusion

OBJECTIVE:

It is essential to identify a serological marker of injury in order to study the pathophysiology of intestinal ischemia reperfusion. In this work, we studied the evolution of several serological markers after intestinal ischemia reperfusion injury in rats. The markers of non-specific cell damage were aspartate aminotransferase, alanine aminotransaminase, and lactic dehydrogenase, the markers of inflammation were tumor necrosis factor alpha, interleukin-6, and interleukin-1 beta, and the markers of intestinal mucosal damage were intestinal fatty acid binding protein and D-lactate. We used Chiús classification to grade the histopathological damage.

METHODS:

We studied 35 Wistar rats divided into groups according to reperfusion time. The superior mesenteric artery was clamped for 30 minutes, and blood and biopsies were collected at 1, 3, 6, 12, 24, and 48 hours after reperfusion. We plotted the mean ± standard deviation and compared the baseline and maximum values for each marker using Student''s t-test.

RESULTS:

The maximum values of interleukin-1 beta and lactic dehydrogenase were present before the maximal histopathological damage. The maximum tumor necrosis factor alpha and D-lactate expressions coincided with histopathological damage. Alanine aminotransaminase and aspartate aminotransferase had a maximum expression level that increased following the histopathological damage. The maximum expressions of interluken-6 and intestinal fatty acid binding protein were not significantly different from the Sham treated group.

CONCLUSION:

For the evaluation of injury secondary to acute intestinal ischemia reperfusion with a 30 minute ischemia period, we recommend performing histopathological grading, quantification of D-lactate, which is synthesized by intestinal bacteria and is considered an indicator of mucosal injury, and quantification of tumor necrosis factor alpha as indicators of acute inflammation three hours after reperfusion.     

The prevalence and clinical characteristics of glucose metabolism disorders in patients with liver cirrhosis. A prospective study

Aims. To define the prevalence and clinical characteristics of glucose metabolism disorders (GMD) in patients with compensated liver cirrhosis (LC).Material and methods. Fasting plasma glucose (FPG) levels were measured to 130 patients with clinically stable LC. Oral glucose tolerance tests (OGTT) and fasting plasma insulin determinations were performed to patients with normal FPG. Insulin resistance (IR) was calculated with HOMA2-IR index. GMD were classified according to FPG and OGTT tests results and to the chronologic relation between diagnosis of diabetes mellitus (DM) and LC as follows: type-2 DM (T2DM), hepatogenous diabetes (HD) and impaired glucose tolerance. Patients from all groups were compared.Results. The prevalence of GMD were as follows: T2DM in 25 patients (19.2%, 95% CI 12.5-25.9), HD in 28 (21.5%, 95% CI 14.5-28.5) and IGT in 36 (38.5%, 95% CI 30.1-46.7). The total of patients with GMD was 79.2% (95% CI 72.3-86.1). In 41% of cases GMD were subclinical and 48.7% of patients had IR. Patients with T2DM had a higher number of variables with significant differences compared with the other groups (more marked compared to the patients without GMD). The only differences between the patients with T2DM and HD were hypercreatininemia: 1.14 ± 0.53 vs. 0.84 ± 0.22 mg/dL (p = 0.005) and family history of DM: 8 (32%) vs. 2 (7%) (p = 0.02).Conclusion. Almost 80% of patients with compensated LC had GMD. Half of them were subclinical. The patients with T2DM had marked clinical differences compared to patients from the other groups, particularly renal impairment.     

Microglial activation and expression of immune‐related genes in a rat ex vivo nervous system model after infection with Listeria monocytogenes

A wide variety of microorganisms has previously been identified as causes of brain infection. Among them, Listeria monocytogenes has a particular tropism for the central nervous system. To gain knowledge about the immune response elicited by L. monocytogenes in the brain, we used a rat ex vivo organotypic nervous system culture as a model for Listeria infection. Scanning electron microscopy (SEM) revealed that activated microglial cells showing a typical amoeboid morphology are quickly recruited to the surface of the explants after the infection. After bacterial engulfment, these cells appear to act as Trojan horses, releasing the engulfed bacteria inside the brain tissue. We describe cycles of microglial phagocytosis, necrotic cell death and the subsequent removal of cell debris for the first time. Furthermore, we used this ex vivo model to assess the expression profiles of immune relevant genes up to 24 h postinfection by means of q‐PCR‐arrays, finding that a number of inflammation‐promoting genes are upregulated. Shortly after infection by L. monocytogenes, upregulated genes were those that encoded molecules involved in Th1 responses, being the Ccl2 chemokine and members of the interleukin1‐β family the most abundant immunomodulatory signals expressed. After 5 h of infection, L. monocytogenes caused a substantial increase in the expression of TLR1 and TLR2 genes, as well as in several downstream genes of the TLR signaling pathways. © 2013 Wiley Periodicals, Inc.     

Submucous tramadol increases the anesthetic efficacy of mepivacaine with epinephrine in inferior alveolar nerve block

The purpose of this study was to evaluate the effect of submucous tramadol as adjuvant of mepivacaine with epinephrine in inferior alveolar nerve block. A double-blind, randomized, placebo-controlled, crossover clinical trial was conducted. Twenty healthy young volunteers were randomized into two treatment sequences using a series of random numbers. Sequence 1: Group A, 2% mepivacaine with 1:100,000 epinephrine plus submucous tramadol 50mg (1mL of saline) and one week later Group B, 2% mepivacaine with 1:100,000 epinephrine plus submucous placebo (1mL of saline). Sequence 2: Group B and one week later Group A. All treatments were administered 1min after that patient informed anesthesia of lower lip. We evaluated the duration of anesthesia of lower lip, anesthetic efficacy, and local and systemic adverse events. Anesthetic efficacy was better in group receiving submucous tramadol during the first 2h compared with group receiving submucous placebo (P<0.05). Submucous tramadol increased the anesthetic efficacy of mepivacaine with epinephrine of soft tissue in inferior alveolar nerve block.