GJB2 mutations: passage through Iran

Hereditary hearing loss (HHL) is a very common disorder. When inherited in an autosomal recessive manner, it typically presents as an isolated finding. Interestingly and unexpectedly, in spite of extreme heterogeneity, mutations in one gene, GJB2, are the most common cause of congenital severe-to-profound deafness in many different populations. In this study, we assessed the contributions made by GJB2 mutations and chromosome 13 g.1777179_2085947del (the deletion more commonly known as del (GJB6-D13S1830) that includes a portion of GJB6 and is hereafter called Delta(GJB6-D13S1830)) to the autosomal recessive non-syndromic deafness (ARNSD) genetic load in Iran. Probands from 664 different nuclear families were investigated. GJB2-related deafness was found in 111 families (16.7%). The carrier frequency of the 35delG mutation showed a geographic variation that is supported by studies in neighboring countries. Delta(GJB6-D13S1830) was not found. Our prevalence data for GJB2-related deafness reveal a geographic pattern that mirrors the south-to-north European gradient and supports a founder effect in southeastern Europe.     

Bryostatin 1-induced modulation of nucleoside transporters and 2-chlorodeoxyadenosine influx in WSU-CLL cells

WSU-CLL cells, a fludarabine resistant B-cell chronic lymphocytic leukemia cell line, has been shown to exhibit enhanced sensitivity to 2-chlorodeoxyadenosine (2-CdA) following 48-72 h exposure to bryostatin 1. For 2-CdA to manifest its chemotherapeutic activity, it must first enter the cell through one of several specific nucleoside transporter systems. We present data to show that bryostatin 1-induced enhanced influx of 2-CdA is in part the result of bryostatin 1-induced modulation of nucleoside transporters in WSU-CLL cells. The bi-directional equilibrative NBMPR sensitive transporters in WSU-CLL cells were significantly down-regulated 90 min post-exposure to 1-200 nM bryostatin 1. This down-regulation was evident up to 144 h. In contrast, WSU-CLL cells exhibited a transient increase in Na+-dependent concentrative 2-CdA influx from 48 to 96 h after bryostatin 1 exposure which was evident for a longer duration than that accounted for by the increase in deocycytidine kinase activity. These data may, in part, explain the enhanced efficacy of 2-CdA seen in WSU-CLL cells following 48-72 h exposure to bryostatin 1. It may raise questions as to the importance of the bi-directional transporters in determining the resistance or sensitivity of CLL cells to 2-CdA or other nucleoside analogues.     

Which donor should be chosen for hematopoietic stem cell transplantation among unrelated HLA-A, -B, and -DRB1 genomically identical volunteers?

The aim of this study was to identify significant prognostic factors by using unrelated genomically HLA-A, -B and -DRB1-identical donors. Such data could help to choose the best donor. We studied 136 consecutive patients with hematologic malignancies and a median age of 32 years (range, 0-55 years) who received hematopoietic stem cell transplantation. Bone marrow grafts were given to 83 and peripheral blood stem cells to 53 patients. The cumulative incidence of grade II to IV acute graft-versus-host disease (GVHD) was 30% and of chronic GVHD was 54%. At 5 years, the overall transplant-related mortality (TRM) was 34%, and patient survival was 50%. In Cox multivariate analysis, 32 potential risk factors were analyzed. Monoclonal antibody OKT-3 during conditioning was correlated with grade II to IV acute GVHD, chronic GVHD, and TRM. HLA-DP mismatch was associated with poor TRM and poor survival. Cytomegalovirus-seropositive patients with a seronegative donor had a decreased leukemia-free survival. Five-year TRM was 14% with no risk factor, 38% with 1 risk factor, and 87% with 2 risk factors. The 5-year survival was 72%, 48%, and 30% with 0, 1, and 2 risk factors, respectively. We concluded that unrelated hematopoietic stem cell transplantation may be improved if an optimal donor and immunosuppression are chosen.     

Establishment of an Animal Model Using Recombinant NOD.B10.D2 Mice To Study Initial Adhesion of Oral Streptococci

An oral biofilm is a community of surface-attached microorganisms that coats the oral cavity, including the teeth, and provides a protective reservoir for oral microbial pathogens, which are the primary cause of persistent and chronic infectious diseases in patients with dry mouth or Sjögren''s syndrome (SS). The purpose of this study was to establish an animal model for studying the initial adhesion of oral streptococci that cause biofilm formation in patients with dry mouth and SS in an attempt to decrease the influence of cariogenic organisms and their substrates. In nonobese diabetogenic (NOD) mice that spontaneously develop insulin-dependent diabetes mellitus (IDDM) and SS, we replaced major histocompatibility complex (MHC) class II (A^g7 E^g7) and class I D^b with MHC class II (A^d E^d) and class I D^d from nondiabetic B10.D2 mice to produce an animal model that inhibited IDDM without affecting SS. The adhesion of oral streptococci, including Streptococcus mutans, onto tooth surfaces was then investigated and quantified in homologous recombinant N5 (NOD.B10.D2) and N9 (NOD.B10.D2) mice. We found that a higher number of oral streptococci adhered to the tooth surfaces of N5 (NOD.B10.D2) and N9 (NOD.B10.D2) mice than to those of the control C57BL/6 and B10.D2 mice. On the basis of our observation, we concluded that these mouse models might be useful as animal models of dry mouth and SS for in vivo biological studies of oral biofilm formation on the tooth surfaces.Oral streptococci are present in large numbers in dental plaque, and several types interact with the enamel salivary pellicle to form a biofilm on tooth surfaces (9, 16, 17, 21, 29). Streptococci account for approximately 20% of the total number of salivary bacteria (24), with Streptococcus salivarius being the primary organism. Further, the densities of Streptococcus mutans and Streptococcus sanguis in saliva are more than 1 × 10⁵ cells per ml. S. mutans is a pioneering organism that plays an important role in biofilm formation on tooth surfaces and is a primary causative agent of dental caries (9, 16, 21). The mechanical forces of salivary flow and tongue movement tend to dislodge and expel bacteria from tooth surfaces and the oral cavity (3, 5, 6), and their importance in controlling microbial colonization in the oral cavity has been well demonstrated in individuals with diabetes mellitus, Sjögren''s syndrome (SS), and dry mouth, who suffer from a rapid overgrowth of biofilm and rampant caries, making them highly susceptible to oral infections (1-2, 6). Thus, attempts to investigate the initial adhesion by oral streptococci, including S. mutans, in mouse models are likely to aid in the understanding and prevention of oral infectious diseases caused by the components of oral biofilm.Previous studies of S. mutans infections in the oral cavities of mice have been performed by feeding the animals diets containing sucrose in the presence of glucans (13, 15, 30, 43). Since the adherence of S. mutans to the tooth surface may depend on the balance between physical adherence and synthesis of insoluble glucans in a natural environment, that infection method may be inappropriate for investigation of natural biofilm formation associated with streptococci, including S. mutans (18, 39).The nonobese diabetogenic (NOD) mouse strain is currently the best available model for the study of insulin-dependent type 1 diabetes mellitus (IDDM) and SS (11, 31), both of which develop spontaneously and are characterized by lymphatic infiltration of the pancreas and salivary glands. Oral changes are prominent features of these diseases, which are manifested by dry mouth and hyposalivation (6, 7, 37). NOD mice are also used as an animal model for the study of oral infectious diseases associated with systemic diseases such as diabetes and SS or dry mouth.The unique major histocompatibility complex (MHC) class II genes (I-A^g7, no expression of I-E) represent dominant susceptibility factors and mediate activated T cells during the development of diabetes in NOD mice (11, 22, 25, 36, 41, 42). In the NOD model of SS, histopathological analyses of the salivary glands in MHC-congenic strains of NOD mice have indicated that the I-A^g7 region is not required for lymphocytic infiltration (26, 31). Further, replacement of the NOD MHC class I K^d region with another haplotype, MHC class I K^wm7, as well as replacement of the MHC class II A^g7 E^g7 and class I D^d regions with the corresponding region from the other MHC haplotype, has been shown to prevent diabetes (12). However, replacement with MHC class I K does not completely prevent development of insulitis. In another report, NOD mice pretreated nasally by using peptides restricted with MHC class I K^d showed a delayed onset of spontaneous IDDM, though insulitis could not be prevented by the induction of tolerance (23).In the present study, we attempted to establish an animal model for oral infectious diseases such as dental caries by focusing on replacement of the MHC class II and class I D region but not the class I K region in nondiabetic NOD mice by outcrossing B10.D2 mice (K^d, I-A^d, and D^d) with NOD mice (K^d, I-A^g7, and D^b) because the MHC class I K region in B10.D2 mice is identical with that in NOD mice (12). The present backcrossed and intercrossed NOD mice with the MHC class II and MHC class I D region replaced with that from B10.D2 mice developed SS, however, not diabetes. We then attempted to determine whether these mice would be useful as animal models for a sucrose-free study of the initial adhesion of oral streptococci on tooth surfaces in humans.     

An improved method for the detection of HIV antigen in the blood of carriers

The measurement of HIV antigen levels in sera or plasma of HIV-infected individuals is critical for determining the existence of antigen or infectious virus before seroconversion and for prognosis. Pretreatment of sera or plasma of HIV carriers by heating at 70 degrees C for 10 min at an acidic pH enabled us to estimate antigens efficiently in immune complexes. This procedure will also be useful in determining antigen levels in HIV carriers more precisely.     

Ganglion cell density and oil droplet distribution in the retina of brown-eared bulbul (Hysipetes amaurotis)

This study was intended to determine the number and density of both retinal ganglion cells and the oil droplets of cone photoreceptor cells in brown-eared bulbul (Hysipetes amaurotis). For this study birds were killed with proper dose of anesthetic (pentobarbital, 30 mg/kg), and the eyes were removed from the orbital cavity to isolate the retina. For the ganglion cell study retinal whole-mount specimens were prepared and stained with 0.1% cresyl violet. The different types of oil droplets were counted from color microphotographs of freshly prepared retinal samples. The mean total number of ganglion cells was estimated at approximately 2.5×10⁶; with an average density of 16 523 cells/mm². Two high-density areas, namely the central area (CA) and the dorso-temporal area (DTA), are located in the central and dorso-temporal retinas, respectively, in bulbuls (24 032 cells/mm² in the CA; 23 113 cells/mm² in the DTA). Small ganglion cells persisted in the highest density areas, whereas the largest soma sizes were found in the lowest density areas of the retina. Four types of different colored oil droplets — red, orange, green and clear — were identified with an average density of 29 062/mm². Among the different colors, the green oil droplets had a significantly higher population (13 083/mm²) than the others across the retina. The central retina had a significantly higher number of all types of oil droplets, at a density of 60 552/mm². The density and size of the different colored oil droplets were inversely related across the regions of the retina. Taken together, it is concluded that the CA of the retina is an excellent quality area for visual perception due to peak density of ganglion cells and oil droplets. Moreover, each specific oil droplet makes a distinct contribution to visual perception, thereby ensuring that the bird has a retina that best matches its natural environment and feeding behavior.     

Comparison of Classical and Clozapine Treatment on Schizophrenia Using Positive and Negative Syndrome Scale of Schizophrenia (PANSS) and SPECT Imaging

Many neuroimaging studies of schizophrenia have shown abnormalities in the frontal cortex, limbic system, basal ganglia, temporal and parietal lobes. These findings are not specific or consistent enough to build up a coherent theory of the origin of the brain abnormality in schizophrenia. This paper describes a state-of-the-art approach of SPECT to correlate neuropsychological evaluation. PANSS scores and different brain focal abnormalities of two groups of patients receiving Clozapine and classical antipsychotic treatments were observed. A total of 20 drug-free patients, actively psychotic schizophrenic, were selected according to the DSM-IV criteria. Pre-Post-treatment was designed using PANSS and 99mTc- ECD-SPECT to assess regional Cerebral Blood Flow (rCBF). The results showed that after treatment, differences in PANSS scores were significant in both groups, with superior scores resulting from the Clozapine therapy. Results were supported by SPECT, which showed a greater improvement in the Clozapine group. Both positive and negative symptoms were improved with Clozapine as well. Before treatment, hypofrontality was the most common (85%) finding, whereas after treatment hypofrontality was mostly cleared. However, in some areas like temporal and caudate, hyperfrontality was induced. Negative symptoms showed linkage to hypofrontality in both groups before and after treatment, and both positive and negative symptoms were improved more with Clozapine therapy than with classical treatment.