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Biomedical subjects

O Günhan

Publications and source records attributed to O Günhan.

At least 19 recordsLinked to original sources
PubMed2005

MIB-1 expression in odontogenic epithelial rests, epithelium of healthy oral mucosa and epithelium of selected odontogenic cysts. An immunohistochemical study.

The aim of this study is to investigate the proliferative potential of rests of odontogenic epithelium found in follicles of unerupted teeth, epithelium of oral mucosa and epithelial linings of various odontogenic cysts. MIB-1 expression was studied in the rests of odontogenic epithelium (n=10), healthy oral mucosa (n=10), odontogenic keratocysts (n=10) and other odontogenic cysts (n=10) using an avidin-biotin peroxidase technique on paraffin sections. The number of positively stained cells was counted on 10 representative areas of epithelium using a x40 objective. The average number of MIB-1 positive cells in each group was calculated. No MIB-1 positive cells were seen in the rests of odontogenic epithelium. The mean numbers of MIB-1 positive cells detected within the epithelium of oral mucosa, and of radicular and dentigerous cysts were similar. The number of MIB-1 positive cells was found to be increased in the presence of marked inflammatory cell infiltration. The highest number of MIB-1 positive cells was seen in the keratocysts. These findings suggest that removal of an unerupted tooth to prevent the possibility of neoplastic transformation of rests of odontogenic epithelium is not a justifiable rationale.

Cell Proliferation↗
PubMed2005

Botryoid odontogenic cyst: report of a case with extensive epithelial proliferation.

Botyroid odontogenic cyst (BOC) is considered a rare multilocular variant of the lateral periodontal cyst. In this report; clinical and histopathological features of a case of BOC found in mandibular mental region of a 32-year-old woman is presented. There was a multilocular radiolucency extending from the roots of the right premolar to the left premolar, involving almost the whole height of the mandible. Histologically, there was extensive intraluminal epithelial proliferation in the lining and MIB-1 positive cells were noted in the basal layer.

Adult↗
PubMed2005

Chondrosarcoma of the parapharyngeal space. A case report.

Chondrosarcomas are the malignant cartilagenous tumors and they are seen rarely in the head and neck area. They are usually slow growing lesions. The head and neck chondrosarcomas may show an aggressive course and the occurrence of this malignant cartilagenous tumor in the parapharyngeal space is only a few. They are mostly located in relation with jaw bones and base of the skull. Chondrosarcomas of the parapharyngeal space are limited in number and among them there is no low-grade one. In this case report, a case of low-grade chondrosarcoma which was treated with a simple excision without neck dissection was reported.

Aged↗
PubMed2004

[Waardenburg syndrome. A heterogenic disorder with variable penetrance].

BACKGROUND: Waardenburg syndrome (WS) is an autosomal dominant disorder characterised by pigmentary anomalies of the skin, hairs, eyes and various defects of other neural crest derived tissues. It accounts for over 2% of congenital hearing impairment. At least four types are recognized on the basis of clinical and genetic criteria. PATIENTS AND METHODS: Based on a screening of congenitally hearing impaired children, 12 families with WS type II were detected. Of special interest was the phenotype of these families, in particular the reduced penetrance of hearing impairment within the families. RESULTS AND CONCLUSION: In all cases a high variability of the disease phenotype was detected and the penetrance of the clinical traits varied accordingly. Therefore, it is not possible to predict the clinical phenotype even in a single family. Based on these studies, we plan to identify the pathogenetic cause of the disease in order to perform a detailed genotype/phenotype analysis.

Genetic Heterogeneity↗
PubMed2003

Dysembryoplastic neuroepithelial tumor in the left lateral ventricle.

Extracortical location of dysembryoplastic neuroepithelial tumor (DNT) is rare. We present a case of DNT localized in the left lateral ventricle of a 21-year-old female patient. Magnetic resonance imaging of the brain showed a round mass lesion in the floor of the anterior horn of the left lateral ventricle. The lesion was hypointense on T (1)-weighted images and slightly hyperintense on T (2)-weighted images without contrast enhancement. Total removal of the yellowish-white colored soft tumor was performed through a transcallosal approach. Histologically, the tumor was of simple type of DNT that was composed of small oligodendrogliocytes clustered tightly about perivascular spaces with neurons floating in mucoid pools showing an eosinophilic fibrillary matrix in the background. The recognition of DNT with an unusual location in lateral ventricle has therapeutic and prognostic significance since DNT is curable by surgical excision and radiation therapy is of no obvious benefit.

Adult↗
PubMed2001

Results of artificial inflammation in scarless foetal wound healing: an experimental study in foetal lambs.

Recent experimental and clinical evidence suggests that the foetus responds to injury in a fashion fundamentally different from the adult. Foetal wound healing occurs without scar formation. The mechanisms causing this difference are still not well defined but absence of inflammation may play a significant role. The aim of this study was to investigate the effects of artificially induced inflammation on scarless foetal wound healing. Twelve time-dated pregnant ewes underwent hysterotomies at 70 and 90 days' gestation. A potent chemoattractant agent (N-formyl-methionyl-leucyl-phenylalanine) was injected into the upper lip of the foetus in the first operation. In the second operation, a full-thickness incisional wound on the right side and a 3-mm excisional wound on the left side of the upper lip were created and closed primarily. A control wound was created on the lower lip. Macroscopic and histologic examinations of the wounds after birth revealed visible scar lines on the upper-lip wounds but no scar line on the lower lip, and an increase in fibrous tissue and collagen content in the upper-lip wounds. We have shown that injecting a chemotactic agent can stimulate inflammation in a period of gestation when tissue injury can not. Although lack of inflammation due to tissue injury in the early period of foetal life may be an important cause of scarless healing, further experimental studies should be carried out to investigate the pathways that are not activated by tissue injury, the immune status of the foetus and the growth factors involved in the inflammatory response.

Animals↗
PubMed2001

Oral nodular fasciitis: a case report.

Nodular fasciitis of the cheek is an extremely rare lesion of the oral cavity. It should be considered in the differential diagnosis of swellings in the oral mucosa. We describe a case of nodular fasciitis and discuss the difficulties of histological and clinical diagnosis of this condition.

Adult↗
PubMed2001

Nasomaxillary osteotomy in lesions of the central compartment of the middle cranial base.

The pituitary fossa, sphenoid rostrum, sphenoid sinus, nasopharynx, pterygopalatine fossa and clivus are the components of the central compartment of the middle cranial base. It is a surgical challenge to gain access to this region. This fact has led to the development of a number of surgical procedures reported in the literature. However, none of these techniques can provide a wide and direct exposure to the middle cranial fossa without morbidity on its own. In this report, nasomaxillary osteotomy is described as a satisfactory alternative to reach the middle cranial fossa. With the nasomaxillary osteotomy technique, a wide access can be obtained to the central compartment of the skull base, caudally till the inferior clivus and upper cervical vertebrae (C1, C2). Since bilateral, internal carotid arteries are in sight laterally, the technique provides a secure resection of tumors with marked lateral extensions. Repositioning the translocated bone segment, surrounding the apertura piriformis, results in satisfactory cosmesis postoperatively. The technique is discussed on the basis of eight cases with the histopathological diagnosis of squamous cell carcinoma (1 case), olfactory neuroblastoma (2 cases), chordoma (2 cases) and juvenile nasopharyngeal angiofibroma (3 cases). No vascular complication has been encountered. One chordoma patient died of the disease in the follow-up period. All other cases, including one squamous cell carcinoma patient, are alive and disease-free without cosmetic deformity. In conclusion, nasomaxillary osteotomy provides a wide and direct exposure to the central compartment of the skull base in a relatively short period of time, securing the vascular and neural structures. Besides, it offers the advantage that it can be combined with other techniques in extensive tumors, while cosmesis and nasal functions are preserved.

Adolescent↗
PubMed2000

Clarithromycin targeting to lung: characterization, size distribution and in vivo evaluation of the human serum albumin microspheres.

Microspheres of clarithromycin have been prepared from human serum albumin using the emulsion polymerization technique. Albumin microspheres containing the active substance were injected into the tail vein of mice. Mice were sacrificed at intervals and microspheres collected from lungs and livers. The clarithromycin amount in microspheres was determined by reversed phase high performance liquid chromatographic (HPLC) method from the mice organs. Morphological and histopathological observations were also reported. The microsphere accumulation began at 10 min, and increased gradually until 6 h, then a decrease was observed. The microspheres were still present after 24 h. In the liver sample, no microsphere accumulation was observed at any time.

Albumins↗
PubMed2000

Oncocytic mucoepidermoid carcinoma of the parotid gland: report of a case with DNA ploidy analysis and review of the literature.

A 44-year-old female presented with a painful mass in the left parotid gland. Histologic examination revealed the characteristic picture of oncocytic mucoepidermoid carcinoma (OMEC) composed mainly of sheets of oncocytic cells with uniform nuclei and eosinophilic cytoplasm, focally smaller epidermoid cells surrounding poorly formed glandular spaces, and a few cystic structures lined by well-differentiated mucous cells with intracytoplasmic mucin. Immunohistochemical staining with antimitochondrial antibody showed granular cytoplasmic positivity in oncocytic cells. The resulting histogram for DNA ploidy analysis was of diploid type. OMEC of the parotid gland is a recently described rare neoplasm. Only six cases have been previously reported in the literature. For an accurate approach in the management of patients, OMEC should be considered in the differential diagnosis of oncocytic lesions of the parotid gland, most of which are benign.

Adult↗
PubMed2000

A histopathological investigation on the effects of the bisphosphonate alendronate on resorptive phase following mucoperiosteal flap surgery in the mandible of rats.

BACKGROUND: The present study was designed to examine histopathologically whether local delivery of aminobisphosphonate (alendronate) could be effective in preventing the alveolar bone resorption associated with mucoperiosteal flaps. METHODS: Following mucoperiosteal flap elevation in the molar region of the rat mandible, a surgical pellet soaked with aminobisphosphonate was locally applied on the exposed bone surface and covered by flap. The determined parameters with a semi-quantitative subjective method for the histopathological evaluation were as follows: existing inflammatory cell infiltration of the related periodontal tissue; fibrotic component content and bundles of collagen fibers; the number and morphology of osteoclasts of the alveolar bone and interdental septum; existing resorption lacunae (osteoclast surfaces); and existing osteoblastic activity (forming surfaces). RESULTS: The results showed that while there were no detectable statistically significant differences between the saline and alendronate-treated groups on the existing inflammatory cell infiltration (ICI), number of osteoclasts, and osteoblastic activity, the results for the fibrotic and collagen component, osteoclast morphologies, and existing resorption lacunae were statistically significant. CONCLUSIONS: These results suggest that local application of the aminobisphosphonate alendronate can be used as an adjunct in therapy for reducing bone resorption following surgery. It can also be suggested for consideration that, even for the surgical approaches in dentistry where bone graft materials and/or dental implants are needed, using bisphosphonate may achieve a new dimension in periodontal therapy in the near future.

Alendronate↗
PubMed1999

Prevention of restrictive adhesions in primary tendon repair by HA-membrane: experimental research in chickens.

Hyaluronic acid (HA) is a glycosaminoglycan polymer that has been found to have some beneficial effects on the prevention of adhesions in primary tendon repairs. The need for slow elimination preparations of HA has been identified. We have combined HA and carboxymethylcellulose (CMC) in order to get a slow elimination preparation of HA and studied its possible effect on primary tendon healing. A gel form of NaHe (19 mg/ml; mw: 6.5 x 10(6)) was mixed with Na CMC (degree of substitution: 0.8) under sterile conditions. A jelly like mixture was thinned and HA membrane was achieved after drying in the refrigerator. The right legs of Leghorn chickens (n = 30) were prepared under IM ketamine anaesthesia by making partial cuts (75%) of flexor profundus tendons at zone II in the second, third and fourth toes, and repaired using a modified Kessler type suture (5/0 nylon). HA-membranes were applied around the repair sites in the third toes while 0.5 ml of hyaluronic acid and saline were poured on to the repair sites in the second and fourth toes, respectively. Skin incisions were closed and the legs were splinted for 15 days. Biomechanical and histological controls were made at the first, second and third postoperative months. No wound dehiscence or exposure of repaired tendons was observed on the operated toes. After collection of samples by amputation at MP levels, two-phalanx free biomechanical assessment was done. The calculated peaks of differential joint motion were very similar to the corresponding non-operated contralateral toes in the HA-membrane treated group. The toe tip displacement curves also resembled the non-operated ones in this group. HA membrane was detected as blue particles on specimens taken at the 30th day following surgery. There were few adhesions in this group microscopically at the third month. Adhesions were similar in the HA treated group while dense adhesions were seen in the saline treated group. These findings suggest that HA membrane acting as a physicochemical barrier can prevent restrictive adhesions in primary tendon repairs.

Animals↗
PubMed1999

Gingival fibromatosis combined with cherubism and psychomotor retardation: a rare syndrome.

Gingival fibromatosis is frequently an isolated condition, but rarely associated with some uncommon syndromes. This paper describes an 11-year-old patient with pronounced gingival enlargement, cherubic facial appearance, and psychomotor retardation and discusses the major aspects of the case. The most striking finding orally was the presence of grossly hyperplastic gingiva, which completely covered all teeth except the occlusal surfaces of some teeth. The swelling in the lower part of the face and the appearance of sclera beneath the iris suggest cherubism. The diagnosis was confirmed by the detection of giant cell regenerative granuloma and perivascular eosinophilic particles and osteoclasts after biopsy of the mandible. In this case, surgery was the only effective way to treat the patient. A full-mouth gingivectomy procedure was performed under general anesthesia in 2 stages. The case was followed for 12 months and no recurrence was seen. An appropriate oral hygiene regimen was established.

Biopsy↗