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Biomedical subjects

Ersin Tan

Publications and source records attributed to Ersin Tan.

16 recordsLinked to original sources

Calpain-3 mutations in Turkey.

Autosomal recessive limb-girdle muscular dystrophies (LGMD2s) are a clinically and genetically heterogeneous group of disorders, characterized by progressive involvement of the proximal limb girdle muscles; the group includes at least 10 different genetic entities. The calpainopathies (LGMD2A), a subgroup of LGMD2s, are estimated to be the most common forms of LGMD2 in all populations so far investigated. LGMD2A is usually characterized by symmetrical and selective atrophy of pelvic, scapular and trunk muscles and a moderate to gross elevation of serum CK. However, the course is highly variable. It is caused by mutations in the CAPN3 gene, which encodes for the calpain-3 protein. Until now, 161 pathogenic mutations have been found in the CAPN3 gene. In the present study, through screening of 93 unrelated LGMD2 families, we identified 29 families with LGMD2A, 21 (22.6%) of which were identified as having CAPN3 gene mutations. We detected six novel (p.K211N, p.D230G, p.Y322H, p.R698S, p.Q738X, c.2257delGinsAA) and nine previously reported mutations (c.550delA, c.19_23del, c.1746-20C>G, p.R49H, p.R490Q, p.Y336N, p.A702V, p.Y537X, p.R541Q) in the CAPN3 gene. There may be a wide variety of mutations, but clustering of specific mutations (c.550delA: 40%, p.R490Q: 10%) could be used in the diagnostic scheme in Turkey.

Adolescent↗

[Human herpesvirus-8 DNA in patients with certain demyelinating disorders].

Infectious etiology of the demyelinating diseases is an intensive matter of research. Among the suspected pathogens, herpesviruses had attracted particular attention because of their capacity to remain latent in nervous tissues, axonal transportation of some members within neurons, relapsing-remitting characteristic of the infections, and capability of inducing demyelination both in human host and animal models. Human herpesvirus-8 (HHV-8) is the least studied of this group even some of the HHV-8 related disorders such as HIV associated Castleman's disease, some lymphomas, monoclonal gammopathy of uncertain significance (MGUS), may be seen in patients with demyelinating conditions. The aim of this study was the investigation of a probable relationship between HHV-8 infection and certain demyelinating diseases. For this purpose, the presence of HHV-8 DNA has been investigated by polymerase chain reaction in the blood samples of 14 multiple sclerosis (MS), six chronic inflammatory demyelinizing polyneuropathy (CIDP), three Guillain-Barre syndrome (GBS), and one Miller-Fisher syndrome patients, together with 24 age- and sex-matched healthy subjects as control. As a result, one of MS, two of CIDP and all of the GBS patients were found HHV-8 DNA positive, whereas all the subjects in control group were negative. Although the interpretation of the results of this study does not seem to be possible owing to the limited number of patients, it emphasizes the need for larger scale, detailed studies on this subject since no other report dealing with this matter has been encountered in the literature.

Adolescent↗

Primary leptomeningeal sarcomatosis; a pathology proven case with challenging MRI and clinical findings.

A 20-year-old male patient admitted with intractable seizures and progressive dementia is presented. Magnetic resonance imaging (MRI) examinations revealed diffuse leptomeningeal thickening, enhancement especially in the basal cisterns and multiple cystic formations in the brain stem, temporal lobes and basal ganglia. The pathologic examination from the right temporal lobe was consistent with leptomeningeal sarcoma. Marked regression of the symptoms and MRI lesions were detected following radiotherapy.

Adult↗

Expression of matrix metalloproteinases in vasculitic neuropathy.

The aim of this study was to investigate the expression pattern and cellular source of matrix metalloproteinases (MMP) in vasculitic neuropathy. Matrix metalloproteinases are endopeptidases degrading components of extracellular matrix proteins, and they have been implicated in the pathogenesis of inflammatory demyelination. They are induced by cytokines, secreted by inflammatory cells, and enhance T cell migration. Vasculitic neuropathy occurs as a component of systemic vasculitis or as an isolated angiitis of the peripheral nervous system, and T cell-mediated inflammation is detected in its pathogenesis. Nerve biopsy sections of eight patients with nonsystemic vasculitic neuropathy (NSVN) and four with systemic vasculitic neuropathy were examined for the presence of CD4+, CD8+, and CD68+ cells and immunohistochemically for MMP-2 and MMP-9 expression. Nerve biopsies of eight patients with noninflammatory neuropathy were used as a control group. Semiquantitative polymerase chain reaction analysis was performed to detect MMP-2 and MMP-9 mRNA. The predominant cells were CD8+ and CD68+ T cells. Expression of MMP-9, but not MMP-2, was increased in perivascular inflammatory infiltrate in nerve tissues of vasculitic neuropathy patients. This MMP-9 expression correlated positively with immunostaining of CD8+ T cells. No difference was detected between immunostaining patterns of nonsystemic and systemic vasculitic neuropathies with the antibodies used, except in MMP-9 immunostaining, which was found to be enhanced in NSVN group. Polymerase chain reaction analysis revealed elevated mRNA levels of MMP-9 and MMP-2 compared with controls, but this did not reach statistical significance. Our results imply a pathogenic role for MMP-9 secreted from CD8+ cells in vasculitic neuropathy.

Adolescent↗

Mutations in a gene encoding a novel SH3/TPR domain protein cause autosomal recessive Charcot-Marie-Tooth type 4C neuropathy.

Charcot-Marie-Tooth disease type 4C (CMT4C) is a childhood-onset demyelinating form of hereditary motor and sensory neuropathy associated with an early-onset scoliosis and a distinct Schwann cell pathology. CMT4C is inherited as an autosomal recessive trait and has been mapped to a 13-cM linkage interval on chromosome 5q23-q33. By homozygosity mapping and allele-sharing analysis, we refined the CMT4C locus to a suggestive critical region of 1.7 Mb. We subsequently identified mutations in an uncharacterized transcript, KIAA1985, in 12 families with autosomal recessive neuropathy. We observed eight distinct protein-truncating mutations and three nonconservative missense mutations affecting amino acids conserved through evolution. In all families, we identified a mutation on each disease allele, either in the homozygous or in the compound heterozygous state. The CMT4C gene is strongly expressed in neural tissues, including peripheral nerve tissue. The translated protein defines a new protein family of unknown function with putative orthologues in vertebrates. Comparative sequence alignments indicate that members of this protein family contain multiple SH3 and TPR domains that are likely involved in the formation of protein complexes.

Adolescent↗

Diffuse spinal and intercostal nerve involvement in chronic inflammatory demyelinating polyradiculoneuropathy: MRI findings.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an uncommon demyelinating disorder with a relapsing and remitting or continuously progressive course. Hypertrophic nerve roots, sometimes associated with gadolinium enhancement, has been reported more commonly in lumbar spine and less commonly in the brachial plexus and cervical roots; however, diffuse involvement of intercostal nerves bilaterally has never been reported previously. We present MRI findings which include diffuse enlargement and mild enhancement of roots and extraforaminal segments of nerves in all segments except a short segment between T12-L2 as well as all the intercostal nerves in a case of CIPD with a 10-year history.

Biopsy, Needle↗

Four novel thymidine phosphorylase gene mutations in mitochondrial neurogastrointestinal encephalomyopathy syndrome (MNGIE) patients.

Mitochondrial neurogastrointestinal encephalomyopathy syndrome (MNGIE) is a rare autosomal recessive neurologic disorder characterised by multiple mitochondrial DNA deletions. In this study, five Turkish MNGIE patients are investigated for mtDNA deletions and TP gene mutations. The probands presented all the clinical criteria of the typical MNGIE phenotype; the muscle biopsy specimens also confirmed the diagnosis with ragged red fibres and cytochrome C oxidase (COX) negative fibres. The mitochondrial DNA analysis revealed no deletions in the probands' skeletal muscle samples. We have identified four novel mutations in the TP gene while one of the patients also harboured a nucleotide change, which was previously reported as a mutation.

Adolescent↗

Andermann syndrome in a Turkish patient.

Agenesis of the corpus callosum with peripheral neuropathy or Andermann syndrome is an autosomal recessive disorder rarely found outside certain regions of the province of Quebec, Canada. We report a 5-year-old Turkish patient with Andermann syndrome born to consanguineous parents. She presented with diffuse hypotonic weakness, predominantly in the distal extremities, and mild mental retardation. Electromyography showed axonal-demyelinating sensorimotor neuropathy. Sural nerve biopsy was compatible with demyelinating neuropathy. Cranial magnetic resonance imaging revealed total agenesis of the corpus callosum, dilatation of the interhemispheric fissure, and enlargement of the cisterna magna. The molecular genetic analysis using microsatellite DNA markers covering the agenesis of the corpus callosum with peripheral neuropathy locus on chromosome 15q13-q15 showed that the patient is homozygous for the whole region. Our findings confirm that Andermann syndrome is a genetically homogeneous disorder.

Agenesis of Corpus Callosum↗

Exercise-induced apoptosis of rat skeletal muscle and the effect of meloxicam.

The aim of this study was to evaluate the effect of exercise on apoptosis in rat gastrocnemius and soleus muscle tissue and to determine the effect of meloxicam, a novel non-steroidal anti-inflammatory drug (NSAID), on the ratio of exercise-induced apoptosis. Forty male Wistar rats were used in the experiments. Spontaneous wheel-running was used as an exercise protocol. Rats were divided randomly into four groups. Group A (n = 10) was the control group, in which rats did not perform any exercise. In group B (n = 10), gastrocnemius and soleus muscles were biopsied immediately after exercise. The rats in group C (n = 10) were placed back in their cages after exercise and allowed to rest for 48 h, after which the gastrocnemius and soleus muscles were biopsied. In group D (n = 10), rats were given 11 mg meloxicam (Mobic, Boehringer Ingelheim) per kilogram body weight per day p.o. for 2 days, after which gastrocnemius and soleus muscles were biopsied 48 h after exercise. The terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP)-biotin nick end labelling (TUNEL) technique was used to detect DNA fragmentation in situ. TUNEL-positive nuclei were identified and counted. The apoptosis ratio in gastrocnemius muscle was 0.50x10(-3)+/-0.96x10(-3) in group A, 5.42x10(-3)+/-3.58x10(-3) in group B, 3.55x10(-3)+/-3.23x10(-3) in Group C and 3.52x10(-3)+/-1.00 in Group D; the ratios in soleus muscle were 0.98x10(-3)+/-1.83x10(-3), 3.03x10(-3)+/-2.78x10(-3), 4.48x10(-3)+/-3.32x10(-3) and 2.91x10(-3) 1.98x10(-3), respectively. The differences between the apoptosis ratios in group A and B, Group A and C, and Group A and D were statistically significant (P < 0.05). There was no statistically significant difference between group C and D. In conclusion, exercise increased apoptosis in gastrocnemius and soleus muscle tissue, and the apoptosis ratios were not affected by meloxicam.

Analysis of Variance↗

A novel homozygous missense mutation in the myotubularin-related protein 2 gene associated with recessive Charcot-Marie-Tooth disease with irregularly folded myelin sheaths.

Mutations in the myotubularin-related protein 2 gene on chromosome 11q22 are known to cause autosomal recessive Charcot-Marie-Tooth disease with irregularly folded myelin sheaths. We screened the coding region of the myotubularin-related protein 2 gene in a Turkish consanguineous Charcot-Marie-Tooth disease family compatible with linkage to chromosome 11q22. A homozygous cytosine to thymine missense mutation at nucleotide position 847, resulting in an amino acid substitution of arginine to tryptophan at codon 283, was detected in exon 9 of the MTMR2 gene. This is the second homozygous missense mutation associated with recessive Charcot-Marie-Tooth disease with focally folded myelin sheaths.

Adolescent↗

Mitochondrial neurogastrointestinal encephalomyopathy: diagnostic features of two patients.

Mitochondrial neurogastrointestinal encephalomyopathy is a rare, multisystem disorder characterized by gastrointestinal dysmotility, ptosis, neurologic findings (e.g., peripheral neuropathy), leukoencephalopathy, and thin body habitus. Gastrointestinal motility studies and skeletal muscle biopsy are recommended diagnostic tools. We report two patients that highlight the diagnostic characteristics of this rare entity.

Adolescent↗

Smooth muscle within incomplete obliterations of processus vaginalis lacks apoptotic nuclei.

INTRODUCTION: Incomplete obliteration of processus vaginalis (PV) has been suggested to result from the persistence of smooth muscle, which should normally disappear after taking part in the descent of testis. Since apoptosis is the mechanism of disappearance, the presence or absence of apoptotic nuclei was evaluated within sacs that result from failed obliteration of PV. MATERIALS AND METHODS: Twenty sacs associated with female inguinal hernia (n = 5), male inguinal hernia (n = 6), hydrocele (n = 5), hydrocele of the cord (n = 2), and undescended testis (n = 2) were evaluated. 10-microm sections were cut from the snap-frozen samples and stained for nuclear DNA fragmentation. RESULTS: Apoptotic nuclei were detected within the vascular structures and mesothelium. However, none of the samples from different diagnostic sources have revealed any apoptotic nucleus within the smooth muscle component. CONCLUSIONS: While the vascular and mesothelial structures within the sacs reveal evidence of apoptosis, the smooth muscle component lacks apoptotic process. The failed apoptosis of smooth muscle may have a role in the persistence of PV.

Apoptosis↗

Role of apoptosis in Duchenne's muscular dystrophy.

We investigated the presence of apoptosis in muscle tissues from 24 patients (average age 5.44 +/- 1.81 years) with Duchenne's muscular dystrophy by in situ tailing of nuclear fragmentation. Muscle tissue from 4 children without histologic evidence of myopathy served as normal controls. Muscle fibers positive for nuclear DNA fragmentation were determined quantitatively by counting an area of at least 400 muscle fibers. Eleven of 24 specimens showed no nuclei with DNA fragmentation. On the other hand, 0.37 +/- 0.48% of fibers in patients with Duchenne's muscular dystrophy and none in controls had DNA fragmentation (P > .05). In this study, the percentage of apoptotic nuclei was higher in Duchenne's muscular dystrophy muscle than in normal controls. However, the difference did not reach a statistically significant level, and further studies with larger control groups are warranted.

Apoptosis↗