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Biomedical subjects

Mehmet Guven

Publications and source records attributed to Mehmet Guven.

5 recordsLinked to original sources

Autologous fat augmentation for voice and swallow improvement after cordectomy.

Surgery for the treatment of early-stage glottic carcinoma still remains a valid option. In most patients, newly formed neocord tissue preserves glottic functions, but in some patients an important glottic gap leading to glottic insufficiency may occur. In our study, 11 patients who had serious glottic insufficiency after endoscopic laser and laryngofissure cordectomy were treated with autologous fat injection (AFI) into the neocord tissue for voice and swallowing rehabilitation. One patient did not attend the first control visit and was excluded from the study. The remaining 10 patients were evaluated in the preoperative and postoperative periods for phonatory functions and efficacy of AFI by videolaryngostroboscopy and computerized acoustic analysis. Phonatory functions showed statistically significant improvement in the shimmer, noise-to-harmonic ratio, maximum phonation time and fundamental frequency. Perceptual ratings (GRBAS scale) also showed statistically significant improvement in all 5 parameters. Despite improvement in glottic closure, the mucosal wave deteriorated. Due to recurrence of symptoms of glottic insufficiency, AFI was repeated in 2 patients at the third and fifth months, respectively. One year later, the AFI resulted in successful rehabilitation of swallowing in all patients. The probability of resorption of autologous fat and the deterioration of the mucosal wave after AFI remain a problem, but re-injection can be done easily. As AFI is an easy, safe and cheap method, we concluded that it is a promising alternative procedure for managing voice problems after laser or laryngofissure cordectomy defects.

Adipose Tissue↗

Bacterial etiology of acute otitis media and clinical efficacy of amoxicillin-clavulanate versus azithromycin.

BACKGROUND: Acute otitis media (AOM) is one of the most common acute bacterial infection in childhood and also the most frequent reason for outpatient antibiotic therapy. Little recent information about susceptibility patterns of AOM bacterial pathogens in Turkish children has been reported. OBJECTIVE: To determine the bacterial etiology of acute otitis media in children and to compare the efficiency of 3 days course of azithromycin with a 10 days course of amoxicillin-clavulanate. METHODS: This prospective, single blind, randomised comparative study was carried out in 180 children with AOM. Paracentesis was performed for middle ear fluid culture before the first dose antibiotic therapy. Children with acute otitis media were randomised to receive either low dose amoxicillin-clavulanate (45/6.4 mg/kg/day in two divided doses for 10 days) or low dose azithromycin (10mg/kg/day for 3 days). Clinical response was assessed on days 2-4, 11-13, 26-28. RESULTS: Bacterial pathogens were isolated from 108 (60%) of 180 children. Streptococcus pneumoniae was the most common isolated pathogen (39.7%), followed by Haemophilus influenzae (20.7%), Moraxella catarrhalis (15.5%), Staphylococcus aureus (13.8%), Group A beta-hemolytic streptococcus (5.1%), Escherichia coli (3.4%) and Enterococcus faecalis (1.7%). This study demonstrated low resistance rates compared to studies of different countries. Although clinical response rates were better in patients treated with amoxicillin-clavulanate, this was not statistically significant [86.6% (78 of 90)] versus [95.2% (80 of 84)]. Success rates of amoxicillin-clavulanate were high for both S. pneumoniae and H. influenzae. Difference between success rates was not statistically significant (P=0.144 and 0.352). CONCLUSIONS: Bacteria were isolated in 60% of AOM cases. The clinical efficiency of amoxicillin-clavulanate was found to be equal compared to azithromycin in children with acute otitis media.

Acute Disease↗

Enhanced sensitivity to oxidant-induced micronucleus frequency in elderly individuals is not associated with glutathione S-transferase M1 (GSTM1) null genotype in lymphocytes.

BACKGROUND: A large number of studies have demonstrated that various kinds of DNA damage accumulate during aging and that oxidative stress possibly contributes to this process. Glutathione S-transferase M1 (GSTM1) can prevent their possible effects on DNA via detoxification of reactive substances that induced oxidative stress. OBJECTIVE: To investigate the relationship between GSTM1 polymorphism and DNA sensitivity to oxidative stress with age, we used micronucleus (MN) frequency as a marker of DNA damage in lymphocytes from young and elderly subjects. METHODS: This study was performed in 30 young (age range 20-36 years) and 30 elderly (age range 66-87 years) healthy individuals who were chosen on the basis of their GSTM1 genotype (15 GSTM1 null and 15 GSTM1 positive for each group). Lymphocytes were cultured after Ficoll isolation and treated for 48 h with a 30-muM dose of cumene hydroperoxide (CumOOH), a dose that does not decrease cell viability. RESULTS: There was no significant difference in the MN frequency observed in control cultures from young and elderly individuals. However, the MN frequency in CumOOH-treated cultures was significantly higher in the elderly group than the young group (p < 0.001). No association was found between the GSTM1 phenotype and CumOOH-induced MN frequency. CONCLUSIONS: The results suggest that lymphocytes of elderly individuals are more susceptible to in vitro MN induction by CumOOH. However, this difference in susceptibility is not explained by the lack of GSTM1.

Adult↗