Mutations in the histamine N-methyltransferase gene, HNMT, are associated with nonsyndromic autosomal recessive intellectual disability.

Histamine (HA) acts as a neurotransmitter in the brain, which participates in the regulation of many biological processes including inflammation, gastric acid secretion and neuromodulation. The enzyme histamine N-methyltransferase (HNMT) inactivates HA by transferring a methyl group from S-adenosyl-l-methionine to HA, and is the only well-known pathway for termination of neurotransmission actions of HA in mammalian central nervous system. We performed autozygosity mapping followed by targeted exome sequencing and identified two homozygous HNMT alterations, p.Gly60Asp and p.Leu208Pro, in patients affected with nonsyndromic autosomal recessive intellectual disability from two unrelated consanguineous families of Turkish and Kurdish ancestry, respectively. We verified the complete absence of a functional HNMT in patients using in vitro toxicology assay. Using mutant and wild-type DNA constructs as well as in silico protein modeling, we confirmed that p.Gly60Asp disrupts the enzymatic activity of the protein, and that p.Leu208Pro results in reduced protein stability, resulting in decreased HA inactivation. Our results highlight the importance of inclusion of HNMT for genetic testing of individuals presenting with intellectual disability.

Transcriptome analysis of the cancer/testis genes, DAZ1, AURKC, and TEX101, in breast tumors and six breast cancer cell lines.

Breast cancer is the most frequent cancer with second mortality rate in women worldwide. Lack of validated biomarkers for early detection of breast cancer to warranty the diagnosis and effective treatments in early stages has directed to the new therapeutic approach. Cancer/testis antigens which have restricted normal expression in testis and aberrant expression in different cancers are promising targets for generating cancer vaccines, monoclonal antibodies, or dendritic cell-based immunotherapy. In this context, we investigated the expression of two known cancer testis genes, Aurora kinase C (AURKC) and testis expressed 101 (TEX101), and one new candidate, deleted in azoospermia 1 (DAZ1), in six breast cancer cell lines including two ductal carcinomas, T47D and BT-474, and four adenocarcinomas, MDA-MB-231, MDA-MB-468, MCF7, and SKBR3 as well as 50 breast cancer tumors in comparison to normal mammary epithelial cells using quantitative real-time reverse transcription PCR (RT-PCR). Results showed significant overexpression (p = 0.000) of all three genes in BT474, DAZ1 in MDA-MB-231, and AURKC and DAZ1 in SKBR3 and significant downregulation (p = 0.000) of AURKC in MCF7 cell line relative to normal breast epithelial cells. Breast tumors showed significant overexpression of AURKC in comparison to normal breast tissues (p = 0.016). The results are noticeable especially in the case of AURKC; however, there is a little knowledge about the nature, causes, consequences, and effects of cancer/testis antigens activation in different cancers. It is suggested that AURKC has effects on cell division via its serin/threonin kinases activity and organizing microtubules in relation to centrosome/spindle function during mitosis.

Stress analysis of mandibular implant-retained overdenture with independent attachment system: effect of restoration space and attachment height.

In this in vitro study, 2 implants were embedded in the interforaminal region of an acrylic model. Two kinds of retention mechanisms were used to construct complete overdentures: ball type and direct abutment (Locator). The ball-type retention mechanism models included 3 different collar heights (1, 2, and 3 mm) with 15 mm occlusal plane height, and 3 different occlusal plane heights (9, 12, and 15 mm) with 1 mm collar height. The direct abutment models included 3 different occlusal plane heights (9, 12, and 15 mm) with 1 mm cuff height. Vertical unilateral and bilateral loads of 150 N were applied to the central fossa of the first molar. The stress of the bone around the implant was analyzed by finite element analysis. The results showed that by increasing vertical restorative space, the maximum stress values around implants were decreased in both unilateral and bilateral loading models. The results also showed that the increase in maximum stress values around implants correlated with the ball attachment collar height. The Locator attachment with a 1 mm cuff height and 9 mm occlusal plane height demonstrated 6.147 and 3.914 MPa in unilateral and bilateral loading conditions, respectively. While a reduction in the collar height of a ball-type retention mechanism and an increase in the vertical restorative space in direct abutment retention mechanisms are both biomechanically favorable, and may result in reduced stress in peri-implant bone, a ball attachment seems to be more favorable in the stress distribution around an implant than a Locator attachment.

Pseudodendritic keratitis in citrullinemia; a report of an unusual and novel ocular finding in this metabolic disorder.

Purpose: To report a 15 year old girl with citrullinemia type 1 and 2 accompanied by neurologic signs and symptoms and a novel ocular complaint in cornea like tyrosinemia type 2. Observations: A 15 year old female was admitted with decreased consciousness and neurologic signs and symptoms. Citrulinemia was discovered through metabolic testing. Later genetic studies revealed mutations in both ASS1 and SLC25A13 genes. Two years after the first presentation, the patient was re-admitted with complaints of bilateral photophobia and tearing. Biomicroscopic examination revealed bilateral corneal haziness with pseudodendritic lesions like tyrosinemia type 2 that were subsided with protein restriction and the use of urea cycle disease (UCD) formula. Conclusions and importance: Citrullinemia is the inherited autosomal recessive disorder of urea cycle that leads to ammonia and accumulation of other toxic substances in the blood. Two types of Citrullinemia have been defined. Citrullinemia type 1, caused by deficiency or reduction in argininosuccinate synthetase enzyme activity due to damaging mutation in ASS1 gene. Citrullinemia type 2 as another subtype is caused by the absence or dysfunction of the mitochondrial membrane carrier protein (SLC25A13), also called CITRIN. Pseudodendritic keratitis is a rare condition that may be seen with tyrosinemia type 2. The association of this ocular complaint with citrullinemia has not been described previously. Awareness of this phenomenon may improve the diagnosis and management of citrullinemia patients.

In vitro Therapeutic Effects of Low Level Laser at mRNA Level on the Release of Skin Growth Factors from Fibroblasts in Diabetic Mice.

BACKGROUND: Numerous in vitro reports suggest that Low Level Laser Therapy (LLLT) affects cellular processes by biostimulation, however most of them emphasize on using visible light lasers which have low penetration. The aim of this study was to determine the effect of infrared laser light (which is more useful in clinic because of its higher penetration) on secretion of Fibroblast Growth Factor (FGF), Platelet Derived Growth Factor (PDGF) and Vascular Endothelial Growth Factor (VEGF), as important growth factors in wound healing. METHODS: Fibroblasts were extracted from the skin of 7 diabetic and 7 nondiabetic mice and cultured. Cell cultures of experimental group were irradiated with single dose of LLLT (energy density of 1 J/cm (2)) using an 810 nm continuous wave laser and the control group was not irradiated. Secretion of growth factors by skin fibroblasts were quantified through real time poly-merase chain reaction. RESULTS: Diabetic irradiated group showed significant increase in FGF (p = 0.017) expression, although PDGF increased and VEGF decreased in both diabetic and nondiabetic irradiated groups, but these variations were not statistically significant. CONCLUSION: These results suggest that LLLT may play an important role in wound healing by stimulating the fibroblasts.

Analysis of CFTR Gene Mutations in Children with Cystic Fibrosis, First Report from North-East of Iran.

OBJECTIVE(S): More than 1500 registered mutations in cystic fibrosis transmembrane regulator (CFTR) gene are responsible for dysfunction of an ion channel protein and a wide spectrum of clinical manifestations in patients with cystic fibrosis (CF). This study was performed to investigate the frequency of a number of well-known CFTR mutations in North Eastern Iranian CF patients. MATERIAL AND METHODS: A total number of 56 documented CF patients participated in this study. Peripheral blood was obtained and DNA extraction was done by the use of routin methods. Three steps were taken for determining the target mutations: ARMS-PCR was performed for common CFTR mutations based on previous reports in Iran and neighboring countries. PCR-RFLP was done for detection of R344W and R347P, and PCR-Sequencing was performed for exon 11 in patients with unidentified mutation throughout previous steps. Samples which remained still unknown for a CFTR mutation were sequenced for exon 12. RESULTS: Among 112 alleles, 24 mutated alleles (21.42%) were detected: ΔF508 (10.71%), 1677delTA (3.57%), S466X (3.57%), N1303K (0.89%), G542X (0.89%), R344W (0.89%), L467F (0.89%). Eight out of 56 individuals analyzed, were confirmed as homozygous and eight samples showed heterozygous status. No mutations were detected in exon 12 of sequenced samples. CONCLUSION: Current findings suggest a selected package of CFTR mutations for prenatal, neonatal and carrier screening along with diagnosis and genetic counseling programs in CF patients of Khorasan.

Evaluation of stress distribution of implant-retained mandibular overdenture with different vertical restorative spaces: A finite element analysis.

BACKGROUND: Available restorative space and bar height is an important factor in stress distribution of implant-supported overdentures. The purpose of this study was to evaluate the effect of different vertical restorative spaces and different bar heights on the stress distribution around implants by 3D finite element analysis. MATERIALS AND METHODS: 3D finite element models were developed from mandibular overdentures with two implants in the interforaminal region. In these models, four different bar heights from gingival crest (0.5, 1, 1.5, 2 mm) with 15 mm occlusal plane height and three different occlusal plane heights from gingival crest (9, 12, 15 mm) with 2 mm bar height were analyzed. A vertical unilateral and a bilateral load of 150 N were applied to the central occlusal fossa of the first molar and the stress of bone around implant was analyzed by finite element analysis. RESULTS: By increasing vertical restorative space, the maximum stress values around implants were found to be decreased in unilateral loading models but slightly increased in bilateral loading cases. By increasing bar height from gingival crest, the maximum stress values around implants were found to be increased in unilateral loading models but slightly decreased in bilateral loading cases. In unilateral loading models, maximum stress was found in a model with 9 mm occlusal plane height and 1.5 mm bar height (6.254 MPa), but in bilateral loading cases, maximum stress was found in a model with 15 mm occlusal plane height and 0.5 mm bar height (3.482 MPa). CONCLUSION: The reduction of bar height and increase in the thickness of acrylic resin base in implant-supported overdentures are biomechanically favorable and may result in less stress in periimplant bone.