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Biomedical subjects

Yildirim A Bayazit

Publications and source records attributed to Yildirim A Bayazit.

At least 19 recordsLinked to original sources
PubMed2006

The A218C polymorphism of tryptophan hydroxylase gene and migraine.

OBJECTIVE: To determine the significance of the A218C polymorphism of the tryptophan hydroxylase (TPH) gene in migraine. METHODS: Fifty-nine migraineurs and 62 healthy controls were included in the study, and polymerase chain reaction - restriction fragment length polymorphism assays were used to determine TPH A218C polymorphism. RESULTS: There was no association between TPH gene polymorphism and gender, family history of migraine and epilepsy, or aura. There was no significant difference between the allele frequencies of both groups (p>0.05). A significant difference was found between the genotypes of the migraineurs and controls regarding the AA genotype. Homozygosity for the C allele or heterozygosity for the A or C was not associated with the occurrence of migraine (p>0.05), but homozygosity for the A allele was less frequent in the migraineurs (p=0.02). CONCLUSION: Since it is unlikely that TPH polymorphism alters serotonin biosynthesis, its association with migraine may be attributed to linkage disequilibrium with a functional variant within the TPH gene or a nearby gene.

Adult↗
PubMed2006

Practical use of MESNA in atelectatic ears and adhesive otitis media.

OBJECTIVE: MESNA is a synthetic sulfur compound that produces mucolysis by disrupting disulfide bonds. This study aimed to address indications and technique of MESNA application in otologic surgery, especially in retraction pockets and adhesive otitis media. METHODS: MESNA application was performed in 42 ears of 39 patients. The diagnoses were retraction pockets fixed to incudostapedial joint, stapes or promontorium, and adhesive otitis media in 24 and 17 ears, respectively. Calculations were performed according to 24 ears of 23 patients with follow-up data. RESULTS: One or more of the following surgical interventions were performed: MESNA application alone and ventilation tube insertion, reinforcement or mastoidectomy in addition to MESNA application. Sensorineural hearing loss was not encountered after MESNA application. The operation was successful in 79.2%. Overall revision surgery was needed in 20.8% of the ears. In 71.4% of the ears treated with MESNA alone, revision surgery was needed. CONCLUSION: In the light of our experience, we advocate the use of MESNA in atelectatic ears, because it makes the operation easy and safe by allowing elevation of the tympanic membrane by its mechanical and chemical actions.

Adolescent↗
PubMed2006

Association of the -1438G/A polymorphism of the 5-HT2A receptor gene with obstructive sleep apnea syndrome.

OBJECTIVE: Serotonergic neurons innervating motoneurons increase their firing rates in response to respiratory challenges, and long-term facilitation of respiratory activity in response to hypoxia is serotonin (5-HT) dependent. Polymorphism of the genes which code for 5-HT receptors may affect functions of the serotonergic system, and may be associated with obstructive sleep apnea syndrome (OSAS). The objective in this study was to assess the significance of T102C and -1438G/A polymorphisms of the 5-HT2A receptor gene in OSAS. METHODS: Fifty-five patients with OSAS and 102 healthy volun teers were included for genetic analyses of T102C and -1438G/A polymorphisms of the 5-HT2A receptor gene. RESULTS: For the T102C polymorphism, there was no significant difference between the patients and controls and both genders (p > 0.05). For the -1438G/A polymorphism, the A/A and G/A genotypes were overrepresented in the patients and controls, respectively (p = 0.045). In the control group, the genotypes of both genders were not significantly different (p > 0.05). In the patients, the A/A and G/A genotypes were overrepresented in males and females, respectively (p = 0.035). Concerning males, the A/A genotype was overrepresented in patients (p = 0.007). CONCLUSION: Serotonergic mechanisms appear to be related to OSAS. The T102C polymorphism of the 5-HT2A receptor gene is not associated with OSAS. However, the -1438G/A polymorphism is associated with OSAS occurrence, especially in male patients. This polymorphism may also be associated with different OSAS incidences of both genders.

Case-Control Studies↗
PubMed2006

An overview of hereditary hearing loss.

Understanding the genetic basis of hearing loss is important because almost 50% of profound hearing loss are caused by genetic factors and more than 120 independent genes have been identified. In this review, after a brief explanation of some genetic terms (allele, heterozygosis, homozygosis, polymorphism, genotype and phenotype), classification of genetic hearing loss (syndromic versus nonsyndromic, and recessive dominant, X-linked and mitochondrial) was performed. Some of the most common syndromes (Usher, Pendred, Jervell and Lange-Nielsen, Waardenburg, branchio-oto-renal, Stickler, Treacher Collins and Alport syndromes, biotinidase deficiency and Norrie disease) causing genetic hearing loss were also explained briefly. The genes involved in hearing loss and genetic heterogeneity were presented.

Alleles↗
PubMed2006

Surgical exposure in retrosigmoid approach: do we need cerebellar retractors?

BACKGROUND: The aim of this study was to present our technique of posterior fossa surgery and to evaluate whether cerebellar retractors are needed. METHODS: Since March 1989, more than 500 surgeries were performed through retrosigmoid approach, and our surgical technique was described. The data were evaluated whether or not cerebellar retractors were used in the operations. RESULTS: The surgeries were vestibular neurectomy, acoustic neuroma removal, and neurovascular decompression in 351, 135, and 14 patients, respectively. Cerebellar retractors have not been used in vestibular neurectomies and in most acoustic neuroma surgeries. The cerebellar retractors have been used in all of the neurovascular decompression surgeries where better exposure of the root entry zones of the cranial nerves is needed, and intracranial endoscopy is applied for further exposure and decompression of the vascular loop. CONCLUSION: There is no need for cerebellar retractors when adequate conditions such as patient positioning, adequate anesthesia techniques, and surgical manipulations are applied in posterior fossa approach except for neurovascular decompression and some of the acoustic neuroma surgeries.

Anesthesia, General↗
PubMed2006

Insulin receptor substrate gene polymorphism is associated with obstructive sleep apnea syndrome in men.

OBJECTIVE: The objective of this study was to assess significance of insulin receptor substrate (IRS) -1 gene polymorphism (Gly972Arg) at codon 972 in obstructive sleep apnea syndrome (OSAS). METHODS: Using the polymerase chain reaction technique, the codon 972 polymorphism of the IRS-1 gene was analyzed in the DNA obtained from leukocytes of 50 patients and 143 healthy controls. RESULTS: An overall comparison between the genotypes and allele frequencies of the patients and controls did not reveal any statistically significant difference between the patients and controls (P > .05). Gender-specific comparisons were not significantly different except for a significant difference between the genotypes and allele frequencies of the male patients and male controls (P < .05). The heterozygous, Gly/Arg variant of the IRS-1 gene was overrepresented and the homozygous, Gly/Gly variant was less frequent in male patients compared with male controls. In the patients with OSAS, there was no correlation between the genotypes and polysomnography parameters on correlation analyses (P > .05). There was no relationship between the genotypes and diabetes mellitus (P > .05). Body mass indices and polysomnography parameters of the patients with and without diabetes mellitus were not significantly different (P > .05). CONCLUSION: The polymorphism of the IRS-1 gene at codon 972, especially Gly/Arg variant, or the presence of the allele for Arg appears to be associated with occurrence of OSAS in male patients, whereas this polymorphism is not related to severity of OSAS.

Adult↗
PubMed2005

Evaluation of the results of endoscope-assisted acoustic neuroma surgery through posterior fossa approach.

The objective of this study was to evaluate the results of endoscope-assisted acoustic neuroma surgery in posterior fossa approach. Between 1996 and 2002, 60 consecutive patients with acoustic neuroma were operated via the retrosigmoid suboccipital approach. Standard 4-mm sinus endoscopes at different angles were used during the surgeries either for inspection or tumor endoscopic dissection. Clinical parameters and treatment outcome were evaluated retrospectively. Tumor sizes were small, medium and large in 46.6, 45 and 8.3% of the patients, respectively. The hearing preservation rate, which did not correlate with tumor size (p > 0.05), was 24.4%. The need for facial reanimation surgery, which was needed in 5% of patients, was significantly higher in the large tumors than in the small and medium tumors (p < 0.001). Cerebrospinal fluid fistula rate, which was not related to tumor size (p > 0.05), was 13.3%. Tumor recurrence or residual tumor was not encountered at all. In conclusion, endoscopes give accurate information about the relationship between the tumor and the adjacent structures and help control the fundus of the internal auditory canal to ensure complete tumor removal. It is also helpful in visually verifying the continuity of the facial and cochlear nerves. The use of endoscopes does not appear to increase the hearing preservation rate, but is very helpful in complete tumor removal in the posterior fossa approach.

Adult↗
PubMed2005

Surgical treatment of peripheral vertigo and vertiginous diseases.

Although our understanding of the mechanisms of vertigo and pathophysiology of vertiginous disorders has increased, diagnosis and treatment of various vertiginous diseases is challenging. The objective for the treatment of a vertiginous disease is to eliminate the underlying pathology either with maneuvers or drugs. In vertiginous diseases, surgery is performed either to eliminate the underlying pathologic event or to create stability in the incoming vestibular signals. It is not always possible to treat the underlying disease. Therefore, surgery is usually performed for the relief of vertigo. There are various surgical approaches used to treat a variety of vertiginous diseases. Selection of the approach depends on the type of vertiginous disease. This review mainly focuses on the current status and outcome of the surgeries used in the treatment of a variety of vertiginous diseases.

Arachnoid Cysts↗
PubMed2005

Combined retrosigmoid retrolabyrinthine vestibular nerve section: results of our experience over 10 years.

OBJECTIVE: We aimed to evaluate the results of our experience in vestibular nerve sectioning (VN), which was performed using combined retrosigmoid-retrolabyrinthine approach. STUDY DESIGN: Medical records of 280 patients who were consecutively operated on for incapacitating peripheral vertigo were retrospectively evaluated, and 210 patients who completed 2 years follow-up and had adequate follow-up data were found to be suitable for inclusion in the study. METHODS: Hearing results, vertigo control rates, and complications of the retrosigmoid-retrolabyrinthine VN were evaluated. RESULTS: The patients were suffering from vertigo for a mean period of 32.2 months. Bilateral Meniere's disease occurred in 5.7% of the patients in the follow-up period. A complete or substantial vertigo control could be achieved in 94.4% of the patients (191 [90.1%] in Class A and 9 [4.3%] in Class B). Preoperative speech reception threshold, pure-tone average, and speech discrimination score of the patients were 56.5 dB, 47.4 dB, and 73.6%, respectively. Postoperative corresponding values were 62.2 dB, 43.4 dB, and 68.5%, respectively (p > 0.05). The complication rate was low (2.5%). Most common complication was abdominal hematoma, which was seen in 4.5%. CONCLUSION: VN performed using retrosigmoid-retrolabyrinthine approach has low complication and high vertigo control and hearing preservation rates. It can be applied as an initial surgery or reserved as the last step when the other surgical treatments have failed to control vertigo.

Adolescent↗
PubMed2005

Bone cement ossiculoplasty: incus to stapes versus malleus to stapes cement bridge.

OBJECTIVE: In this study, our purpose was to evaluate results of our experience with bone cement repair of ossicular discontinuity between the incus and stapes and between the malleus and stapes. METHODS: Medical records of patients who underwent surgery for chronic otitis media between March 2000 and December 2002 were evaluated retrospectively. Fifty-seven patients who underwent bone cement ossiculoplasty and had appropriate follow-up data were included in the study. Bone cement reconstruction of the ossicular chain was performed 1) from incus to stapes (I-S) in the absence of long arm or lenticular process of the incus and 2) from malleus to stapes (M-S) in the absence of the incus. The clinical data of the patients were evaluated by otoscopic examination and audiometry. RESULTS: The graft take rate was 84.1%. I-S procedure was performed in 42 and M-S in 8 patients. Pre- and postoperative PTAs of all patients were compared, which showed a significant improvement in air PTA (p < 0.001) while bone PTA did not change (p > 0.05). In I-S and M-S groups, successful hearing restoration could be achieved in 78.6.1% and 87.5% of the patients, respectively. Hearing results of different aural pathologies (chronic otitis media and conductive hearing loss) and surgeries (tympanotomy and tympanoplasty with or without mastoidectomy) were not significantly different (p > 0.05). CONCLUSION: Bone cement ossiculoplasty offers cost effective and significant improvement in conductive hearing loss.

Adult↗
PubMed2005

Association of serotonin transporter gene polymorphism with obstructive sleep apnea syndrome.

BACKGROUND AND OBJECTIVE: Obstructive sleep apnea syndrome (OSAS) is a common condition characterized by repetitive pharyngeal collapse during sleep and daytime sleepiness. There is genetic predisposition to sleep disorders. Serotonin is involved in the regulation of sleep. The synaptic 5-hydroxytryptamine (HT) is inactivated by presynaptic reuptake, which is mediated by the serotonin transporter. Blockage of the serotonin transporter leads to increased extracellular 5-HT. Polymorphism of the serotonin transporter gene (STG) leads to alterations in serotonin level and may be important in OSAS. In this study, we aimed to assess the role of STG polymorphism in OSAS. METHODS: Twenty-seven OSAS patients and 162 healthy volunteers were involved in the study. STG polymorphism was investigated using leukocytes obtained from peripheral blood. RESULTS: There was no difference between the genotypes and allele frequencies of the patients and controls regarding VNTR and HTTLPR polymorphisms (P > .05). The VNTR and HTTLPR variants and the frequencies of 12/12, 12/10, L, and S alleles were not significantly different between male and female control subjects (P > .05). The 12/12 and SS genotypes were over-represented in the female patients, whereas 12/10 and LL genotypes were over-represented in the male patients (P < .05). The genotypes 12 to 12 were over-represented in the male controls, whereas the genotypes 12 to 10 and L/S were over-represented in the male patients (P < .05). The alleles 10 and L were more frequent in the male patients than male controls (P < .05). The genotypes of female patients and female controls were not significantly different (P > .05). The allele 10 and L were less frequent in the female patients than female controls with Fisher's exact testing (P < .05). There was no relation between genotypes and clinical data of the patients (P > .05). CONCLUSION: STG polymorphism appears to be associated with the occurrence of OSAS, especially in male patients. Absence of association of between genetic variants and polysomnography findings may suggest that some mechanisms other than STG polymorphism are involved in OSAS pathophysiology. Our results need confirmation in a larger group of patients with OSAS.

DNA Primers↗
PubMed2005

Tuberculous deep neck infection in a soldier, preceding miliary tuberculosis: a diagnostic dilemma.

Tuberculosis can affect every organ, most importantly the lungs, and worldwide it is the leading cause of death attributable to a single infectious agent. Tuberculous involvement of the neck is also possible. Patients mostly present with masses or draining fistulas in the neck, which are mostly located in the posterior cervical, submandibular, and supraclavicular regions. We report on a soldier who presented with a tuberculous deep neck infection, followed by miliary tuberculosis. The clinical presentation and diagnostic dilemmas are discussed.

Adult↗
PubMed2004

Hydatid cyst of the thyroid gland in a child.

The hydatid cyst tend to form in the liver or lung but may be found in any organ of the body, including brain, heart, and bones. Thyroid gland involvement is rather rare. Cyst leakage or rupture may even associated with severe allergic reaction to parasite antigens, and may cause anaphylactoid reactions. Herein we reported an additional case of hydatid cyst of the thyroid gland that occurred in a 9-year-old boy who admitted with a painless and cystic thyroid mass. Hemithyroidectomy was performed, and histopathology confirmed the diagnosis of hydatid cyst. Diagnosis of that rare clinical entity is unlikely prior to surgical excision and histopathologic examination. Despite this fact, hydatid disease of the thyroid should be remembered in the differential diagnosis of the cystic thyroid masses, and a high index of suspicion is required.

Child↗
PubMed2004

An analysis of the single-stage tympanoplasty with over-underlay grafting in tympanosclerosis.

OBJECTIVES: Our objective was to analyze the results of tympanosclerosis surgery using over-underlay tympanoplasty and to find out the effect of single-stage surgery on hearing results. MATERIALS AND METHODS: Forty-two patients who were operated on for tympanosclerosis between July 1998 and February 2002 were included in the study. These were one-stage tympanoplasties, because second-stage operations and revisions were not included. Operative records and audiograms of the patients were obtained. Of the patients, 48% had bilateral tympanosclerosis. In three (7.1%) of the patients, tympanosclerosis and cholesteatoma occurred concomitantly. The cog was present in eight (20%) of 40 mastoidectomies. Körner's septum was present in nine (22.5%) patients. The graft take rate was 95.2%. RESULTS: The pre- and postoperative air-bone gap values of the patients were not significantly different (p > 0.05). Thirty-three percent of the patients met the successful hearing criteria (air-bone gap <20 dB). However, 47% had an air-bone gap closure between 20 dB and 30 dB, whereas 20% had a gap of more than 30 dB. CONCLUSION: Single-stage surgery does not result in a satisfactory hearing improvement in most of the patients with tympanosclerosis. Only one third of the patients, most of whom had a mobile stapes, had satisfactory hearing results. Mobilization of a fixed stapes is not an effective option for hearing restoration in tympanosclerosis. Second-stage surgery for stapedectomy and placement of a prosthesis-like piston or total ossicular replacement prosthesis should be considered to obtain better hearing results in tympanosclerosis.

Audiometry, Pure-Tone↗
PubMed2004

Cutaneous involvement in Hodgkin's lymphoma: report of two cases.

Hodgkin's lymphoma (HL) comprises 20 to 30% of all lymphomas. Skin involvement is almost always secondary to visceral or nodal involvement. Secondary cutaneous HL is rare, occurring in only 0.5 to 3.4% of the cases. Herein we report two cases of skin involvement in Hodgkin's disease. One was a 25-year-old female admitted with a draining sinus in the neck. The other was a 19-year-old female admitted with a neck mass and skin papules on her chest and arm. Skin involvement may antecede or can be seen during the course of HL. Better understanding of such cutaneous involvement, which occasionally may be the initial sign of HL, is needed, and a biopsy of any suspicious skin lesion should be considered.

Adult↗