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Biomedical subjects

E Yüksel

Publications and source records attributed to E Yüksel.

18 recordsLinked to original sources
PubMed2003

Direct filtration with preozonation for small water treatment systems.

The possibility of applying preozonation followed by direct filtration without the use of a coagulant is investigated. Filtration experiments have been carried out using four different water sources within Istanbul. A 1 m deep bed of 0.8-1.2 mm silica sand was used as the filter medium. The filter was operated at a rate of 11.5 m/hr. Raw water turbidities ranged from 2.3 NTU to 10.0 NTU. Effluent turbidity and particle count values were monitored using an on-line turbidimeter and an on-line particle counter. With all the waters studied in this work, preozonation improved particle removal in direct filtration. With three of the mentioned waters, it was possible to achieve turbidity values below 1.0 NTU without a coagulant by applying ozone at a rate between 1.7-1.8 mg/L. It was not possible to reduce the turbidity of one of the waters to below 2.7 NTU even with very high ozone dosages. The need for pilot testing before deciding if this treatment method is applicable to a given water is underlined.

Filtration↗
PubMed2003

On the use of crushed shells of apricot stones as the upper layer in dual media filters.

The use of crushed shells of apricot stones instead of anthracite coal in dual-media filters is investigated. Turbidity removal efficiencies were measured for several filtration rates in dual media filters composed of shells of apricot stones above silica sand and anthracite coal above silica sand. Backwash (fluidization) experiments were carried out using sieved fractions of crushed shells of apricot stones to establish curves of expansion versus backwash velocity at 25 degrees C. Such curves can be used in the design of filters employing this material. It is believed that the use of such a locally available and cheaper alternative filter medium would be of interest in many small water and wastewater treatment systems around the world.

Biodegradation, Environmental↗
PubMed2002

Centralised versus decentralised treatment and disposal options for Küçükçekmece Basin of Istanbul city.

Küçükçekmece Lake is a sea lagoon located on the European side of Istanbul city with a drainage area of 4 million inhabitants (year 2040). The original plan to treat all of the wastewater collected from the drainage basin in a single plant located at the Northern end of the lake is compared with the decentralised option involving 4 treatment plants. The initial investment cost of the decentralised option is estimated to be higher than the original plan by an amount of 43 million US $. However, the decentralised option has been chosen finally, considering the low cost and risk of wastewater collection, the possibility of the staging of the services, and the reduced environmental impacts.

Cities↗
PubMed2002

Effect of ozone injection location on filter performance in direct filtration.

Two identical pilot scale sand filters were operated in parallel to study the effects of preozonation in direct filtration. No coagulants were used. The influent of one filter was ozonated, whereas the influent to the second filter was aerated. Significantly improved reduction in turbidity, particle count, and iron was observed with the filter receiving preozonated water. The head loss development rate was increased as a result of using ozone. In a second set of experiments, the effects of ozone injection point on filter performance were investigated. Two identical filters both receiving preozonated water were operated. With one of the filters, the raw water was ozonated immediately before it entered the filter. The entrance of the preozonated water to the other filter was delayed by using a detention tank between the ozone contact chamber and the filter. In addition to effluent turbidity and particle count values, zeta potentials of the waters entering the two filters were measured. Head loss development at several locations within each filter bed was also observed and recorded. Slightly better effluent quality (turbidity and particle count) was observed with the filter receiving preozonated water without delay. It was observed that the zeta potential of the prezonated water became more negative with increasing delay time.

Equipment Design↗
PubMed2000

Role of increased arterial inflow in arm edema after modified radical mastectomy.

Chronic arm edema is a common finding after modified radical mastectomy and its pathophysiology is unclear. In a prospective study the value of increased arterial inflow and venous abnormalities after mastectomy was evaluated. Arterial and venous blood flow in axillary vessels of 39 patients with arm swelling and 16 patients without swelling were investigated by Doppler ultrasound. In patients with arm edema the arterial flow on the surgical treated side was 689.73+/-44.6 (mean+/-sem) ml/min and 427.73+/-30.8 ml/min on the contralateral side (p<0.05). In those without swelling the flow was 447.75+/-37.8 ml/min on the treated side and 354.95+/-28.7 ml/min on the contralateral side (p>0.05). The difference between arterial flow measurements on the treated sides of the patients with and without arm swelling was statistically significant. There was no significant difference between the measurements on the contralateral sides of both groups. Venous abnormalities were not detected in both groups of patients. We, therefore, conclude that modified radical mastectomy causes increased inflow in ipsilateral arm and it may play an important role in the etiology of arm swelling in breast cancer patients.

Adult↗
PubMed1999

Development of acute promyelocytic leukemia with isochromosome 17q after BCR/ABL positive chronic myeloid leukemia.

We describe a pediatric case of acute promyelocytic leukemia with an i(17q) after treatment of BCR/ABL positive chronic myeloid leukemia (CML) for 3.5 years. The patient was treated with Busulphan, alpha-2a interferon, hydroxyurea, and cytosine arabinoside at various times in the course of the chronic phase of CML, because he had no HLA-identical donor for bone marrow transplantation. Hematologic remission was achieved for a short time, but cytogenetic remission was never possible. When promyelocytic blast crisis was diagnosed according to the French-American-British classification, cytogenetic studies revealed an i(17q) as a new feature in our patient. The promyelocytic transformation was associated with the appearance of an i(17q) preceding CML are discussed in the light of recent literature.

Bone Marrow↗
PubMed1999

Perioperative dilation for vessel-size discrepancy using a percutaneous transluminal angioplasty catheter.

The problem of vessel-size discrepancy is still unsolved in microvascular-free tissue transfers. In an effort to develop a technique perioperatively to dilate smaller vessel diameters, the authors utilized a catheter customarily used in coronary angioplasties, the percutaneous transluminal coronary angioplasty (PTCA) catheter. Twenty New Zealand rabbits were divided into two groups: Group 1 consisted of 14 experimental animals; Group 2 of six control animals. In both groups, a segmental defect of 2 cm was created in the proximal portion of the femoral artery just below the inguinal ligament, where the vessel diameter is 2.0+/-0.1 mm. In Group 1 animals, an arterial graft was harvested from the superficial femoral artery in the contralateral lower extremity, where the vessel diameter is 1.0+/-0.1 mm. The arterial graft along its entire length was dilated, using a PTCA catheter up to 2 mm in diameter. The duration of dilation was 3 min with pressure applied at 2.5 atm. Before and following dilation, sections were obtained from both ends of the graft for histologic comparison. The grafts were then interposed within the defect and microvascular anastomoses were performed. In the control group, an arterial graft of the same length as in the experimental group was harvested from the contralateral upper femoral region, where the vessel diameter is 2.0+/-0.1 mm. These grafts were then interposed within the defect and microsurgically anastomosed. Seven days later, the patency of the anastomoses was evaluated in both groups. In 13 of 14 rabbits in the experimental group, the anastomoses were patent and the arterial grafts maintained their dilated diameters (2 mm). In all six control animals, the anastomoses were patent. A statistical comparison of vessel patency using Fischer's exact chi-square test showed no significant differences between the experimental and control groups (p = 0.7). Histologically, the dilated arteries demonstrated intact endothelial layers.

Anastomosis, Surgical↗
PubMed1999

Local gene delivery: arterial thrombosis model for endothelial cell-targeted thrombolytic gene therapy research.

The authors describe a rabbit arterial thrombosis model that employs vessel division followed by microsurgical anastomosis and transluminal sutures, to reliably induce thrombus formation in the common femoral artery (CFA). Using two objective measures, "evacuation/refill" evaluation of patency and computer-aided histomorphometric analysis of the thrombus area, thrombus formation was confirmed and characterized in the model at both short- and long-term observation time-points. In addition, a gene delivery method was developed in the CFA that employs an adenoviral vector solution injected through the inferior epigastric artery (IEA). Using this method, a marker transgene (beta-galactosidase) was delivered to endothelial cells locally and without trauma. By subsequently performing beta-galactosidase staining, effective endothelial transfection was demonstrated simultaneously with endothelial viability, with preserved endothelial synthetic function in the immediate environment of the occluding thrombus. The results suggest that these two techniques can be used together in one model, to effectively introduce a foreign therapeutic transgene into endothelial cells and to evaluate the effect of the expressed protein product in a consistent in vivo thrombosis system. This combined model may be used as one of several assays of efficacy in future endothelial cell-targeted thrombolytic/antithrombotic vascular gene therapy research.

Adenoviridae↗
PubMed1999

Transfer of flexor carpi ulnaris branch of the ulnar nerve to the pronator teres nerve: histomorphometric analysis.

Partial median-nerve injury high in the upper extremity, resulting from brachial plexus neuritis or trauma, can affect the pronator teres muscle and result in the inability to pronate the forearm. A nerve transfer from an ulnar nerve-innervated branch to the flexor carpi ulnaris (FCU) muscle to the branch to the pronator teres (PT) is an attractive option in this clinical scenario. This study, a histomorphometric analysis of nine cadaver specimens harvested at the proposed FCU branch to PT branch transfer site, demonstrates sufficient similarities between the two branches in total number of nerve fibers (371.6 with SEM 35.1, and 361.9 with SEM 47.1; p = 0.87) and nerve cross-sectional area (122,181 microm2 with SEM 14,546 microm2, and 142,492 microm2 with SEM 19,633 microm2; p = 0.42), to predict a functional transfer result. In addition, clinical application of this transfer resulted in functional pronation strength of M4+.

Aged↗
PubMed1998

CT findings of hydatid cyst with unusual location: infratemporal fossa.

Hydatid disease has a high incidence in the countries of the temperate zones such as Turkey. Only few cases in the head and neck region have been reported in the literature. Our case, an unusual localization of hydatidosis, i.e. hydatid disease of the infratemporal fossa of a 9-year-old male patient suffering from a swelling of the left maxillary region which was diagnosed by CT, is presented. The lesion visualized on CT images was compressing the neighbouring structures. The possible diagnosis was made based on the images obtained from CT examination.

Child↗
PubMed1998

Head and neck reconstruction with the latissimus dorsi musculocutaneous pedicled flap: functional preservation of the muscle by staged transfer.

The reconstruction of soft-tissue defects in the head and neck region with the latissimus dorsi musculocutaneous pedicled flap is traditionally carried out with dissection of a transaxillary subcutaneous tunnel, which may result in compression of the vascular pedicle in the tunnel, a contour deformity of the neck, or morbidity to the tissues in the axilla and the neck (such as hematoma and seroma). Furthermore, the flaps are often bulky and require secondary defatting. Loss of the muscle causes contour deformity in the back, and its functional loss may be a concern for the patient. To overcome such drawbacks of the traditional use of the flap, we devised a technique of regional transfer of the latissimus dorsi musculocutaneous pedicled island flap to the head and neck region over a pectoral skin bridge rather than utilizing a transaxillary subcutaneous tunnel. This is a two-stage procedure. During the first stage the musculocutaneous flap is transposed in an extracutaneous route to the recipient site. Following a 3-week neovascularization period, the second stage is performed, during which the muscle is detached from its overlying skin island and replaced in situ. This technique was utilized successfully in 5 patients for reconstruction of various head and neck defects with no complications. We conclude that this staged technique of latissimus dorsi musculocutaneous flap transfer to the head and neck region enables functional preservation of the muscle and overcomes many of the complications of the traditional method of utilizing a transaxillary subcutaneous tunnel.

Cicatrix↗
PubMed1997

A case of bladder agenesis.

Agenesis of the bladder is a rare anomaly, and it is usually associated with the absence of the urethra. In the case report herein, a normal urethra was found with ureters emptying into the posterior urethra. The right kidney was non-functioning and small.

Humans↗
PubMed1996

An axillary arch.

An axillary (axillopectoral) muscle (arch) was observed extending between the upper border of the latissimus dorsi and the lower border of the pectoralis major muscles in a 48-year-old male cadaver during our dissections. In the same cadaver, the pectoralis major muscle has entirely inserted into the most distal part of the tendon of deltoideus.

Axilla↗
PubMed1995

Failure of the isthmus lobe to fuse in the midline.

Four developmental anomalies of the thyroid gland are to be noted: a pyramidal lobe, failure of the lobes of thyroid tissue to develop, failure of the isthmus to fuse, and absence of a significant part of the lateral lobes. We encountered failure of the isthmus to fuse in the midline of the thyroid gland in a 48-year-old female cadaver.

Cadaver↗
PubMed1993

An accessory flexor digitorum longus muscle.

An accessory flexor digitorum longus muscle (M. flexor digitorum longus accessorius) in a 60-year-old male cadaver was encountered during routine dissections in our laboratory. The muscle originated from the deep transverse fascia of the leg, covering flexor digitorum longus, flexor hallucis longus, and tibialis posterior muscles, and additionally from some fibres of these muscles. After the tendon of the muscle passed behind the medial malleolus, it inserted into the tendon of the flexor digitorum longus muscle where the latter separated into four digital tendons.

Foot↗