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Biomedical subjects

Atakan Aydin

Publications and source records attributed to Atakan Aydin.

At least 19 recordsLinked to original sources
PubMed2006

New universal primers facilitate Pyrosequencing.

A cost-driving factor in Pyrosequencing is the need for single-stranded PCR products that are usually obtained by biotin-labeling of one primer. We designed new universal primers that allow the introduction of biotin during the specific PCR at either the forward or the reverse primer in a single reaction. When converting five human single nucleotide polymorphism assays from the standard format into the universal format, we obtained pyrograms of similar good quality. Although the universal nonhuman sequences are unlikely to form loop structures, we mostly failed to establish assays without using the proprietary software from Biotage AB. Nevertheless, our universal primer pair adds flexibility to the process of assay design due to optional strand selection and contributes to the reduction of genotyping costs.

Apolipoproteins↗
PubMed2006

[The results of digital replantations at the level of the distal interphalangeal joint and the distal phalanx].

OBJECTIVES: We retrospectively evaluated replantations performed for distal amputations. METHODS: The study included 82 patients (75 males, 7 females; mean age 29 years; range 10 to 52 years) who underwent replantations distal to the distal interphalangeal joint for a total of 98 amputations. According to the Tamai classification, there were 58 zone 1 and 40 zone 2 amputations. Local digital anesthesia was used in 77 patients (93.9%). Arterial anastomosis was accomplished after bone fixation, and venous anastomosis and nerve repair were performed whenever possible. When venous anastomosis was not possible or in case of venous insufficiency, venous decompression was performed with heparinized gauze placed on the bleeding nail matrix. Functional results and the degree of patients' satisfaction with the cosmetic outcome were evaluated. The mean follow-up was 16 months (range 3 to 46 months). RESULTS: Replantation was successful in 60 amputations (61.2%) and unsuccessful in 38 cases (38.8%). In successful cases, cosmetic results were satisfactory due to the preservation of the nail and finger length. Functional results were satisfactory in cases in which the distal interphalangeal joint could be preserved. Replantations for zone 1 amputations (74.1%) yielded better results than those performed for zone 2 amputations (42.5%). CONCLUSION: Despite technical difficulties, replantations for distal finger amputations can provide satisfactory functional and cosmetic results.

Adolescent↗
PubMed2006

[Pedicled flap procedures for sensory restoration of the hand: long-term results].

OBJECTIVES: We evaluated the long-term results of patients who underwent reconstruction with pedicled flaps for soft tissue and sensory restoration. METHODS: The study included 30 patients (26 males, 4 females; mean age 33 years; range 16 to 62 years) who underwent sensory restorations of the thumb (n=24), the index finger (n=3), and the little finger (n=3). Twenty-seven patients received neurovascular island flaps and three patients received radial innervated cross-finger flaps. Disconnection-reconnection of the nerve was performed in 11 patients receiving a neurovascular island flap. Sensory evaluations were made with two-point discrimination and the Semmes-Weinstein monofilament test. The mean follow-up was 29.2 months (range 5 to 144 months). RESULTS: There were no cases of flap loss. Contractures of donor digits were seen in four patients (14.8%) treated with neurovascular island flaps. Neuroma formation was noted in two patients (18.2%) in whom the disconnection-reconnection technique was used. Static and moving two-point discrimination test results were 9.1 mm and 7.4 mm with the disconnection-reconnection technique, 8.3 mm and 7 mm with the original technique, and 10.3 mm and 8.6 mm with radial innervated cross finger flaps, respectively. Sensation was at the recipient site in all the patients who underwent disconnection-reconnection. Of those in whom the original technique was employed, nine patients (56.3%) localized sensation at the recipient site, three patients (18.8%) at the donor site, while four patients (25%) showed double sensibility. CONCLUSION: Pedicled flaps are reliable and satisfactory alternatives for soft tissue and sensory restoration of hand injuries and disconnection-reconnection of the nerve is effective in preventing double sensibility.

Adolescent↗
PubMed2006

[Treatment algorithm in synovial tuberculosis of the hand and wrist: a report of three cases].

Three patients with synovial tuberculosis are presented. Involvement was in the hand in one patient, and in the wrist in two patients. None of the patients had pulmonary tuberculosis or a family history of tuberculosis. Tuberculosis treatment was initiated only after histologic verification. The cultures remained negative. The patients received a 12-month course of multidrug chemotherapy for tuberculosis, resulting in symptomatic improvement and healing. There were no recurrences during a follow-up period of 16 to 26 months. Our clinical observations showed that tuberculosis tenosynovitis benefited well from antituberculosis chemotherapy.

Adolescent↗
PubMed2005

Sculpturing a fibular flap: combined horizontal/vertical osteotomy and ostectomy for reconstruction of complex craniofacial defects with one flap.

A fibular flap has great versatility in reconstructive procedures. Osteomies and ostectomies enable the flap to be used for variable defects. We used combined horizontal/vertical osteotomy and ostectomy for reconstruction of complex craniofacial defects with one flap in two patients. Vertical osteotomy transforms the tubular structure of a fibula into a flat bone that can be used for reconstruction of wider defects with less vertical height. Neither vertical osteotomy nor ostectomy had negative effects on viability and bony healing of the segments in our patients. We think that the fibular flap, thanks to its versatility, can be used for reconstruction of complex orbito-zygomatic and orbito-cranial defects successfully.

Craniofacial Abnormalities↗
PubMed2005

Association of vascular injury with the proximal side branch and assessment of thrombosis rates in a new microarterial traction model.

The higher rate of anastomotic failure in avulsion injuries has been attributed mostly to the uncertainty in determining the uninjured vessel segment suitable for anastomosis and resection past a proximal branch that has been proposed to achieve good arterial flow. A graded, longitudinal, microarterial traction model in rats has been used to examine the histopathologic aspects of the extent of vascular injury and its association with the proximal side branch. Additionally, anastomoses were performed following traction, and thromboses rates were determined. Results indicated a more proximal vessel injury with increasing rates of traction and, although the vessel segment proximal to the side branch was spared, up to a certain degree of traction, the injury extended beyond this point with more aggressive traction force. Consistently increasing rates of thromboses, significantly higher than the control group, were demonstrated. This model may be of use in further studies on the efficacy of various antithrombotic agents.

Animals↗
PubMed2005

Brachioradialis transposition for elbow extension in obstetrical brachial plexus palsy.

Disorders of elbow extension occur following traumatic or neurologic injuries of the triceps muscle. Restoration of elbow extension is an integral part of the entire upper extremity surgical reconstruction to improve the following daily activities: bringing down an object from above, handwriting, using the hand in the supine position, steering a wheelchair, driving a car, and swimming. The transfer of the posterior head of the deltoid muscle to triceps (Moberg procedure) and the transfer of the biceps to triceps (Friedenberg procedure) are previously described procedures for the functional restoration of triceps function. In conditions where these procedures cannot be used, we describe a new technique for restoration of elbow extension. In 4 cases with obstetrical palsy sequela, where shoulder abduction was established with the latissimus dorsi and teres major transfer, restoration of elbow extension was planned to aid in activities performed while the hand is above the head. To achieve this goal, the brachioradialis muscle was transposed bipedically to the triceps muscle.

Adolescent↗
PubMed2004

Single nucleotide polymorphism map of five long-QT genes.

We screened a white population for single nucleotide polymorphisms (SNPs) in five long QT syndrome genes, namely, KCNQ1 (LQT1), HERG (LQT2), SCN5A (LQT3), KCNE1 (LQT5), and KCNE2 (LQT6). We found 35 SNPs, 10 of which have not been previously described. Ten SNPs were in KCNE1, six in HERG, eight in KCNQ1, four in KCNE2, and seven in SCN5A. Four SNPs were associated with QTc interval in our 141 subjects, one in KCNE1, one in KCNE2, and two in SCN5A. Two of these SNPs have not been described. We conclude that these five long QT syndrome genes contain common variants, some of which are associated with QTc interval in normal persons. We suggest that analysis of these SNPs in a much larger cohort would enable establishment of common haplotypes that are associated with QTc. These haplotypes could facilitate prediction of arrhythmia risk in the general population.

Cohort Studies↗
PubMed2004

Circumferential trachea reconstruction with a prefabricated axial bio-synthetic flap: experimental study.

OBJECTIVE: The ideal method, in reconstruction of circumferential tracheal defects more than 50% of the total tracheal length, is still a question. Current methods lack either in epithelial lining or in skeletal framework. In this study, we designed an axial biosynthetic prefabricated flap to reconstruct the circumferential tracheal defects in rabbits. METHODS: Ten rabbits are used. The inner mucosal lining is substituted by hairless epithelium obtained from proximal ear. The tracheal cartilage is substituted by polypropylene mesh and the tracheal adventitia is substituted by lateral thoracic fascia as a vascular supply. The study is designed in three stages. Stage 1: Hairless epithelial graft is obtained by secondary healing of a full thickness skin defect in ear. Stage 2: Epithelial graft, polypropylene mesh and lateral thoracic fascia are tubed around a silicone catheter. This structure is dissected through its pedicle (lateral thoracic vessels and fascia) to the axilla and mobilized. The prefabricated neotrachea is carried on its pedicle to the cervical area through a subcutaneous tunnel formed superficial to the sternum and left there for 2 weeks. Stage 3: The silicone catheter is taken out and prefabricated neotrachea is adapted to the defect formed in native trachea and anastomized. Later the animals are evaluated for 4 weeks. The patency of the lumen, the viability of the epithelial graft and fascia, airtightness of the anastomoses and other features of the reconstruction are evaluated by radiological, macroscopical and histological examinations. RESULTS: Survival at 4 weeks was 70%. All of the prefabricated neotracheas and epithelial grafts were viable. The rigidities, longitudinal elasticities, diameters and wall thickness were similar to native tracheas. Occlusion of lumen is encountered only in one animal. There was no hair growth from the epithelial lining. CONCLUSION: The study defines a new method of circular tracheal reconstruction with successful substitution of inner lining, skeletal framework and vascular supply.

Anastomosis, Surgical↗
PubMed2004

External decontamination of wild leeches with hypochloric acid.

BACKGROUND: Medicinal leech, Hirudo medicinalis, has been used in plastic and reconstructive surgery, to relieve venous congestion and to improve the microrevascularization of flaps. In many countries, wild leeches are still provided from local markets and utilised with antibiotic prophylaxies. In this research, results of identification of bacteria in the transport fluid is reported, oral and intestinal floras and the antibiograms of the identified microorganisms are investigated. Also, to avoid possible infections, the ability of hypochloric acid, a disinfectant, to suppress the relevant microorganisms without changing the life style and behavior of leeches in terms of sucking function, is investigated. METHODS: Bacterial identifications and antibiograms of oral and intestinal flora and transport medium were performed for 10 leeches. The optimum concentration of hypochloric acid which eliminated microorganisms without affecting the viability and sucking function of the leeches were determined by dilution of hypochloric acid to 100, 50, 25, 12.5, 6.25 ppm concentrations in different groups of 25 leeches. Finally, 20 leeches were applied atraumatically to the bleeding areas of rats, the duration of suction was determined and compared statistically between the leeches treated and not treated with hypochloric acid solution. RESULTS: Aeromonas hydrophilia was the most commonly identified microorganism and found to be resistant to first generation cephalosporins, frequently used in prophylaxis at surgical wards. In the next stages of the study, the leeches were subjected to a series of diluted hypochloric acid solutions. Although disinfection of the transport material and suppression of the oral flora of hirudo medicinalis were successful in 100, 50, 25, 12.5, 6.25 ppm concentrations; 12.5 ppm solution was the greatest concentration in which hirudo medicinalis could survive and sucking function was not affected significantly. CONCLUSIONS: External decontamination of wild leeches with 12.5 ppm hypochloric acid enables bacterial suppression without causing negative effects on leech sucking function and life.

Aeromonas↗
PubMed2004

Does preoperative abduction value affect functional outcome of combined muscle transfer and release procedures in obstetrical palsy patients with shoulder involvement?

BACKGROUND: Obstetric palsy is the injury of the brachial plexus during delivery. Although many infants with plexopathy recover with minor or no residual functional deficits, some children don't regain sufficient limb function because of functional limitations, bony deformities and joint contractures. Shoulder is the most frequently affected joint with internal rotation contracture causing limitation of abduction, external rotation. The treatment comprises muscle release procedures such as posterior subscapularis sliding or anterior subscapularis tendon lengthening and muscle transfers to restore the missing external rotation and abduction function. METHODS: We evaluated whether the preoperative abduction degree affects functional outcome. Between 1998 and 2002, 46 children were operated on to restore shoulder abduction and external rotation. The average age at surgery was 7.6 years and average follow up was 40.8 months. We compared the postoperative results of the patients who had preoperative abduction less than 90 degrees (Group I: n = 37) with the patients who had preoperative abduction greater than 90 degrees (Group II: n = 9), in terms of abduction and external rotation function with angle measurements and Mallet classification. We inquired whether patients in Group I needed another muscle transfer along with latissimus dorsi and teres major transfers. RESULTS: In Group I the average abduction improved from 62.5 degrees to 131.4 degrees (a 68.9 degrees +/- 22.9 degrees gain) and the average external rotation improved from 21.4 degrees to 82.6 degrees (a 61.1 degrees +/- 23 degrees gain). In Group II the average abduction improved from 99.4 degrees to 140 degrees (a 40.5 degrees +/- 16 degrees gain) and the average external rotation improved from 33.2 degrees to 82.7 degrees (a 49.5 degrees +/- 23.9 degrees gain). Although there was a significant difference between Group I and II for preoperative abduction (p = 0.000) and abduction gain in degrees (p = 0.001), the difference between postoperative values of both groups was not significant (p = 0.268). There was also no significant difference between the two groups in the preoperative external rotation, the external rotation gain and the postoperative external rotation (p = 0.163, p = 0.181 and p = 0.803, respectively). CONCLUSIONS: Obstetric palsy patients with shoulder sequela who had a preoperative abduction less than 90 degrees hadas good functional results using latissimus dorsi, teres major muscle transfer and subscapularis muscle release as the patients who hada preoperative abduction greater than 90 degrees.

Adolescent↗
PubMed2004

Autosomal-dominant hypertension with type E brachydactyly is caused by rearrangement on the short arm of chromosome 12.

We are studying a Turkish family with autosomal-dominant hypertension and brachydactyly; affected persons die of stroke before 50 years of age. With interphase fluorescence in situ hybridization, we found a chromosome 12p deletion, reinsertion, and inversion in affected persons. This finding suggested that the hypertension could be caused by one or more of 3 genes, the ATP-dependent potassium channel Kir6.1, its regulator the sulfonyl urea receptor SUR2, and the phosphodiesterase PDE3A. We further studied 6 affected and 4 nonaffected persons. Buttocks biopsies were done, small vessels were tested on a myograph, and mRNA was extracted. We performed forearm blood flow studies with intrabrachial artery diazoxide, isoproterenol, and milrinone infusions. Systemic pharmacological testing was done with intravenous diazoxide, nitroprusside, and isoproterenol. PDE3A mRNA was high in vessels from 3 affected subjects, but not high in 3 others. The vessels responded similarly to forskolin, with or without glibenclamide, and to cromakalim. However, there was a suggestion that the dilatation after milrinone might be exaggerated. The forearm infusion studies showed no differences in the responses to diazoxide, isoproterenol, or milrinone. Systemically, affected persons showed a greater blood pressure response to diazoxide and nitroprusside, and a greater heart rate response to isoproterenol than nonaffected persons. The results shed doubt on Kir6.1 and SUR2. The differences in PDE3A expression and responses may be the result of hypertension rather than the cause. Although our 3 candidate genes are no longer likely, the rearrangement we describe greatly enhances the perspectives of this project.

Arteries↗
PubMed2004

Validation of fluorescence-labeled artificial nonhuman sequences for single-strand conformation polymorphism mutation detection in familial hypercholesterolemia.

We developed a two-in-one, polymerase chain reaction (PCR)-based method with a specific amplification step and a universal amplification step in one tube to screen for the presence of DNA variations. The method relies on fluorescence-labeled artificial nonhuman sequences for mutation detection. To document utility, we applied this method as a high-throughput capillary single-strand conformation polymorphism screening system to identify 30 mutations in the low-density lipoprotein receptor gene. The sensitivity of mutant allele detection compared to wild-type allele detection was 93%. We conclude that the "two-in-one PCR" is sensitive, simple, and cost effective.

Animals↗
PubMed2004

Effect of hyperbaric oxygen therapy on nerve regeneration in early diabetes.

Nerve regeneration in diabetes is essential for reversal of neuropathy as well as the recovery of nerves from injury due to acute nerve compression and entrapment. Endoneural hypoxia due to hyperglycemia-induced blood flow reductions is observed early in the course of diabetes, and the resultant ischemia plays a role in the diminished neural regeneration. Hyperbaric oxygen therapy is capable of producing tissue hyperoxia by raising oxygen tensions in ischemic tissues, and was shown to be beneficial in the reversal of experimental ischemic neuropathy. In this study, an experimental diabetes model was used to evaluate the functional and histomorphological effects of hyperbaric oxygen therapy on early diabetic nerve regeneration. Our results indicate that there is significant histomorphological impairment of nerve regeneration, even in very early stages of diabetes. However, no beneficial effects of hyperbaric oxygen therapy could be demonstrated at this stage.

Analysis of Variance↗
PubMed2004

Effects of amifostine on healing of microvascular anastomoses, flap survival, and nerve regeneration with preoperative or postoperative irradiation.

Amifostine is an organic thiophosphate compound, which has both cytoprotective and radioprotective effects. An experimental study was undertaken to investigate the effects of its use on reconstructive surgery in cancer treatment. One hundred and twenty guinea pigs were divided into three equal groups to investigate flap survival and healing, patency of microvascular anastomoses, and nerve regeneration, respectively. The groups were subdivided in such a way that they were given either preoperative or postoperative radiotherapy, with or without amifostine treatment. Macroscopic and planimetric examination, light and electron microscopy, and histomorphometric analyses were performed to evaluate flap survival and healing, patency of arterial anastomoses, and nerve regeneration. Although flap survival rates were not affected, significantly better flap healing was observed in the postoperative radiotherapy subgroup with amifostine treatment. However, amifostine treatment did not result in a statistically significant difference in terms of anastomotic patency and nerve regeneration with either preoperative or postoperative radiotherapy.

Amifostine↗
PubMed2004

The negative effect of hyperbaric oxygen therapy at the acute phase of electrochemical esophageal burn induced by button battery ingestion.

OBJECTIVE: Ingestion of button battery, if lodges in esophagus, causes mucosal destruction in esophagus and may damage surrounding tissues due to electrochemical reactions which may lead to esophagus perforation, tracheosefageal fistula and other serious problems. We designed an experimental study to test the effect of hyperbaric oxygen therapy on battery induced electrochemical tissue damage in the esophagus of a rabbit model and possible change with duration of contact time. METHODS: Button batteries were inserted in esophagus of 40 rabbits which were divided into four groups. Groups 1 and 2 had 15 min of duration of contact time of battery in esophagus, while Groups 3 and 4 had 30 min. Groups 1 and 3 had hyperbaric oxygen therapy for 3 days; Groups 2 and 4 did not. At the end of 3rd day all animals were sacrified and samples were taken from the esophagus for determination of malondialdehyde levels and for histopathological examination to compare: mucosal destruction, muscular layer involvement, perforation and tracheal involvement between groups. RESULTS: Malondialdehyde levels, mucosal destruction, muscular layer involvement, perforation and tracheal involvement were significantly higher in groups which had 30 min of contact time compared to groups which had 15 min. The same assessments were significantly higher in Group 1 (15 min of contact time with hyperbaric oxygen therapy) compared to Group 2 (15 min of contact time without hyperbaric oxygen therapy). However, the difference between Group 3 (30 min of contact time with hyperbaric oxygen therapy) and Group 4 (30 min of contact time, no hyperbaric oxygen therapy) was not significant. CONCLUSION: Our study demonstrated that if contact time is 15 min HBO had an additive adverse effect to electrochemically burned esophagus by increasing free radicals and eventually tissue damage. However, if the contact time is 30 min its adverse effect is shielded by huge electrochemical destruction due to long contact time.

Acute Disease↗