Biomedical subjects

K Bakir

Publications and source records attributed to K Bakir.

18 recordsLinked to original sources

PubMed2002

Efficacy of methylprednisolone in acute experimental cauda equina injury.

In this experimental study the efficacy of methylprednisolone was investigated by neurophysiological and histopathological evaluation in a rabbit cauda equina model where injury was produced with an aneurysm clip (closed pressure 192 gr). High dose methylprednisolone (kg/30 mg) was administered by intravenous infusion in the 8th, 16th and 24th hours after injury followed by infusion of the same dosage every 6 hours for 24 hours. Nerve conduction velocity was measured before and early after trauma and 3 weeks after injury. Both neurophysiological and histopathological investigations demonstrated the neuroprotective effectiveness of methylprednisolone if it was given in the 8th hour after trauma. Although recovery was observed its efficacy was less pronounced when it was given in the 16th and 24th hours.

Animals↗

PubMed2002

The inhibition of pro-inflammatory cytokines with pentoxifylline in the cardiopulmunary bypass lung.

In addition to preventing tissue energy loss during cardiopulmonary bypass, pentoxifylline (Ptx) prevents the production of pro-inflammatory cytokines as well. The aim of this study was to investigate whether Ptx decreases the inflammatory effects of cardiopulmonary bypass on the lungs during open-heart surgery. The patients in the study group (n = 15) who were going through an open-heart surgery had 500 mg l(-1) of Ptx added to their prime solution, whereas the patients in the control group (n = 10) only received prime solution. Pre-pump and post-pump blood samples were obtained from both groups and assayed for interleukin-6 (IL-6), interleukin-8 (IL-8) and tumour necrosis factor alpha (TNFalpha). Lung tissue samples that were obtained after the pump were examined with light microscopy and stained for tissueTNFalpha. Non-parametric Wilcoxon test was utilized for statistical evaluation. In the post-pump period, the difference in the IL-6, IL-8 and TNFalpha levels of the two groups was found to be statistically significant (P<0.005). The tissue samples from the control group had significant staining with TNFalpha. We think that Ptx has important protective effects on the lungs during cardiopulmonary bypass.

Adult↗

PubMed2002

Prognostic factors and c-erbB-2 expression in non-small-cell lung carcinoma (c-erbB-2 in non-small cell lung carcinoma).

The human proto-oncogene c-erbB-2/neu gene, which is structurally similar to the epidermal growth factor receptor gene, encodes a transmembrane protein of 185 kDa (p185) with tyrosine kinase activity. Paraffin-embedded sections from 42 cases with lung carcinoma were stained immunohistochemically using the Avidin-Biotin Horseradish Peroxidase method to search for c-erbB-2 reaction. Results were evaluated semiquantitatively. The c-erbB-2 expression from each case was compared according to tumor type, grade, mitotic activity, clinical stage and lymph node metastasis. Results were statistically analyzed by using chi-square tests. We were unable to detect a significant relation between c-erbB-2 expression and histological grade, nodal metastasis, number of mitotic figures or tumor type, but we did observe a statistically significant correlation between clinical stage and increased c-erbB-2 expression (p < 0.05). In our opinion, c-erbB-2 expression in human lung carcinomas may be useful for determining clinical outcome.

Carcinoma, Non-Small-Cell Lung↗

PubMed2002

Clinical and histopathological correlates of the proliferative activity in squamous cell laryngeal carcinoma.

OBJECTIVES: To elucidate the clinical and histopathological significance of the proliferative activity as determined by PCNA and Ki67 levels and mitotic counting (MC) in laryngeal squamous cell cancer (LSCC). STUDY DESIGN: An analysis of clinical, histopathological and immunhistochemical (PCNA0 and Ki67) results of 28 patients, who were treated for LSCC, was made. METHODS: Clinical data of the patients were reviewed and corresponding archival paraffin embedded tissue samples were obtained. Histopathological studies and MC were performed, and PCNA and Ki67 positivity was assessed. RESULTS: There was no association between the mean values of the proliferative markers, and N stage and T stage of the patients as well as laryngeal site of involvement (p > 0.05). There was a correlation between the proliferative indicators and tumor grade (p < 0.05). A correlation was also encountered between the PCNA, Ki67 and MC values (p = 0.02). CONCLUSION: The proliferative markers studied are not reliable indicators for the presumptive diagnosis of occult neck metastasis. They may be used as complementary tools to the conventional histopathologic grading systems to assess the tumour differentiation in LSCC.

Adult↗

PubMed2002

Bernard-Soulier syndrome in a Turkish family.

This report describes the first Turkish family to be diagnosed with Bernard-Soulier syndrome. The family consists of nine members (two parents, three sons and four daughters). The parents were first cousins. The index case, a 22 year-old-man, had a history of haemorrhagic diathesis with thrombocytopenia, giant platelets in the peripheral blood smear and a prolonged bleeding time. Refractory idiopathic thrombocytopenic purpura had been diagnosed elsewhere and a splenectomy had been performed six months previously. Ristocetin agglutination of platelets was defective and flow cytometry analysis of platelet membrane glycoprotein showed markedly reduced expression of glycoprotein lb (2.1%). Bernard-Soulier syndrome was diagnosed. Increased mean platelet volume was found in both parents, one son and three daughters. The other son and daughter were normal.

Adult↗

PubMed2001

Renal tubular injury induced by hyperoxaluria: evaluation of apoptotic changes.

In order to evaluate the injurious effect of hyperoxaluria on renal tubular epithelium, as judged by apoptotic changes in the renal parenchyma, we performed an experimental study in 20 rabbits. In the experimental group animals (n = 10) severe hyperoxaluria was induced by continuous ethylene glycol (EG; 0.75%). Histologic alterations, including crystal formation, together with apoptotic changes were evaluated after 7 and 28 days. Control group animals (n = 10) received normal distilled drinking water. Following 7- and 28-day periods, tissue sections obtained from kidneys were examined histopathologically under light microscopy for the presence and the degree of crystal deposition in the tubular lumen. Apoptotic changes in renal tubular cells were examined using the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP in situ nick and labeling (TUNEL) method during the same follow-up period. Crystal deposition was evident in the tubular lumen of tissue sections obtained during the 7-day examination period. During the 28-day examination period, however, these findings were found to be either limited or to have disappeared. In relation to apoptotic changes, the percentage of positive nuclei stained using the TUNEL method was from 11 to 20% in the experimental group and 5.6% in the control group. Our findings indicate that both calcium oxalate (CaOx) crystals and hyperoxaluria itself may be injurious to renal tubular cells, as indicated by apoptotic changes. These changes may be responsible for the pathologic course of urolithiasis.

Animals↗

PubMed2001

Eosinophilic granuloma of the temporal bone.

Histiocytosis X or Langerhans cell histiocytosis (LCH) is a disease that possesses three less distinctive and overlapping states called eosinophilic granuloma (EG), Hand-Schuller-Christian (HSC) disease and Letterer-Siwe (LS) disease. EG is the least severe and localized form of all LCHs and possesses the best prognostic result. A high index of suspicion is required to diagnose the EG, especially when an ear disease is refractory to medical treatment. Early detection is important to manage the EG properly and to minimize the complications or sequels of treatment. Definitive diagnosis of histiocytosis is made by histopathological means and immunohistochemical detection of S-100 and CD1 antigens in the tissue samples. And differential diagnosis of the subgroups is made according to the clinical manifestations such as visceral organ or bone involvement. Surgical excision, radiotherapy and chemotherapy, either alone or in combination, are the main treatment options.

Biopsy↗

PubMed2001

AgNOR/P53 expression compared with different grades in bladder carcinoma.

OBJECTIVE: The aim of this study is to assess the relation between silver-strained nucleolar organizer regions (AgNOR)/P53 expression and urothelial neoplasm of the bladder which graded according to the WHO/ISUP tumor grading system. METHODS: Transurethral resection materials (TUR) and cystectomy specimens from 52 patients with bladder urothelial carcinomas were stained by AgNORs and analyzed immunohistochemically using an avidinbiotin peroxidase method for p53 staining and also silver for AgNORs. RESULTS: Nuclear p53 accumulation was determined in two of 5 LMP cases (%40), in 10 of 22 LGC (%45.4), and in 8 of 25 HGC (%32). Positivity of p53 accumulation was observed in 20 (%57.7) of all cases. There was no statistically significant relationship between AgNOR score of p53(+) and p53(-) cases. There was no correlation between LGC and LMP, also between LGC and HGC (p > 0.05), but a meaningful relationship was found between LMP and HGC (p = 0.03). Association between P53 and grade, AgNOR value and grade, p53 and AgNOR was found statistically insignificant. CONCLUSIONS: Although we found a statistically significant correlation between AgNOR count of LMP and HGC, this study did not show a satisfying correlation between AgNOR, p53 and any grade of urothelial carcinoma.

Carcinoma, Transitional Cell↗

PubMed2001

Unilateral testicular torsion: evaluation of bcl-2, p-53 and PCNA expression in contralateral testes.

OBJECTIVES AND METHODS: The present study aims to evaluate the histologic as well as apoptotic changes indicated by PCNA, p-53 and bcl-2 expression in the contralateral testes after a period of unilateral testicular torsion of 4 h. RESULTS: Regarding the histologic changes, while some significant alterations such as complete or incomplete spermatocytic arrest as well as sertoli cell only formation have to some extent been noted after the detorsion procedure, reasonably better preserved histology could be demonstrated following the orchiectomy procedure both in the early and late follow-up. Thus, the orchiectomy procedure was found to be limiting enough on the severity of the histologic changes in the contralateral testes after a certain period of time following the torsion procedure. On the other hand, however, in relation to the apoptotic events indicated by the three markers, while PCNA activity was found to be significantly different depending on the procedure performed (detorsion or orchiectomy), p-53 and bcl-2 positivity did not exhibit any difference in this aspect. Increased PCNA activity (especially after the detorsion procedure) together with marked positivity of p-53 both in the early and late follow-up indicated the increased cell turnover in the contralateral testes, which in turn may be accepted as a sign of increased apoptosis in these testes. In addition to these findings, bcl-2 expression has been found to be consistently negative in all specimens evaluated both in the early and late follow-up. CONCLUSION: Taking into account the strong inhibitory effect of bcl-2 during apoptotic events, these findings again support the likelihood of increased apoptosis in the contralateral testes.

Animals↗

PubMed2001

Malignant mixed tumor of the larynx: a case report.

Malignant mixed tumour (MMT), which is a salivary gland tumour, is the malignant form of pleomorphic adenoma. Although the tumour can also originate from the minor salivary glands throughout the submucosa in the head and neck region, laryngeal involvement is quite rare. An additional case of laryngeal MMT presented in a forty-five year old man, and the diagnostic, immunohistochemical (S-100, actin, vimentin, epithelial membrane antigen) and therapeutic procedures were presented.

Humans↗

PubMed2000

A thyroglossal duct cyst with calcification.

We report a thyroglossal duct cyst with calcification, the second case in the world literature. The ultrasound and CT findings are described and we highlight the differential diagnosis.

Adult↗

PubMed2000

Inflammatory pseudotumor of the lung.

Inflammatory pseudotumors of the lung are uncommon in the thoracic surgical literature. These masses resemble carcinoma of the lung radiographically and are discovered only at time the of histologic review of the resected specimen. We report a case of inflammatory pseudotumor that was excised without pulmonary resection, although it completely filled the right hemithorax. We think it was the greatest inflammatory pseudotumor in the English literature.

Biopsy↗

PubMed2000

Significance of Fas protein in squamous cell carcinoma of the larynx.

The purpose was to elucidate the clinical significance of Fas protein in laryngeal squamous cell carcinoma (LSSC). Medical records of 30 patients who were operated for LSCC between 1991 and 1997 were reviewed, and histopathological and immunohistochemical studies of the archival tumor tissues were performed. Conventional histopathology included tumor grading, mitotic counting (MC) and status of the cervical lymph nodes. The monoclonal antibodies to Fas (DAKO M 3554) and nm23 (DAKO A0096 Lot 035) proteins were used for immunohistochemical staining. Streptavidin-Biotin, horseradish method was used. Positive staining for both Fas and nm23 was obtained in 27 (90%) tumor samples. There was no correlation between neck metastasis and Fas positivity (r = 0.126, p = 0.505 and chi2 = 0.062, p = 0.996, respectively). Fas positivity did not correlate to grade (r = 0.282, p = 0.130), tumor size or T (r = 0.0457, p = 0.810, chi2 = 0.0.018, p = 0.999) or laryngeal site of involvement (chi2 = 0.0937, p = 0.992). However, a correlation was found between Fas and MC (r = 0.482. p = 0.007). There was also a correlation between Fas and nm23 positivity (r = 0.614, p < 0.0001). Fas protein expression has no prognostic value in LSCC, because the Fas values do not correlate with grade, stage or nodal status of neck. However, 90% of LSCCs expressed Fas protein. Understanding the functional status of the Fas receptor proteins may lead to development of new therapeutic options for LSSC in the future.

Aged↗

PubMed1999

Penile epithelioid sarcoma: MR imaging findings.

Magnetic resonance imaging findings of a 38-year-old man with epithelioid sarcoma of the penis is presented. It started as a firm, painless and slowly growing nodule at the base of his penis 6 months previously which caused pain radiating to the testis during coitus. It has been well known that sarcomas may well mimic reactive processes. Initial presentation of epithelioid sarcoma may provoke considerable diagnostic difficulty, and its differentiation from benign lesions, such as Peyronie's disease and chronic inflammation, may be a clinical problem. In our present report the MR findings are compared with those of the epithelioid sarcomas of various locations reported in the literature and differential diagnosis of the entity is discussed. To our knowledge, this is the first report regarding the MR findings of the epithelioid sarcoma of penis.

Adult↗

PubMed1999

Limitation of shockwave-induced enhanced crystal deposition in traumatized tissue by verapamil in rabbit model.

OBJECTIVE: To evaluate the possible protective effect of verapamil (a calcium channel blocking agent) against the traumatizing effects of high-energy shockwaves (HESW) and new stone formation, as indicated by crystal deposition in the renal parenchyma, an experimental study was performed in rabbits. METHODS: A total of 65 rabbits were included. During severe hyperoxaluria induced by continuous ethylene glycol (EG) (0.75%) administration, animals in the first group (N = 15) received EG only, and animals in the second group underwent administration of 500 to 1500 shockwaves, animals in the third group (N = 15) received verapamil (0.1 mg/kg) for 3 days prior to HESW application, a control group (N = 15) received various numbers (500 to 1500) of shockwaves alone. Sham-treated animals (N = 5) constituted the last group in our study. Three months after shockwave application, tissue sections obtained from treated and untreated kidneys were evaluated histopathologically under light microscopy and transmission electron microscopy (TEM) for the presence and degree of crystal deposition in the cortical parenchymal region subjected to HESW. RESULTS: Whereas crystal deposition was evident in the intercellular region and intratubular parts of the parenchyma in animals receiving EG and HESW, especially in those receiving relatively higher numbers of shockwaves), animals receiving verapamil demonstrated limited or no crystal formation. No significant crystal deposition could be noted in specimens from animals undergoing either EG or SWL alone, and sham-treated animals demonstrated no significant alteration, as expected. CONCLUSION: Using this model, the traumatic effects of HESW could be evaluated as a factor in new stone formation after SWL. Verapamil has been found to be protective against crystal deposition.

Animals↗

PubMed1999

Epitheloid sarcoma of the penis.

We report a case representing the clinical as well as histopathologic features of epitheloid sarcoma. Both a clinical review and the results of definitive treatment together with the follow-up data are presented.

Adult↗

PubMed1999

Unilateral testicular torsion: protective effect of verapamil on contralateral testicular histology.

In this experimental study, it was our aim to reduce the effects of ischemic insults to the contralateral testicle after unilateral testicular torsion. The protective effect of a calcium channel blocking agent (verapamil) on the histology and the tubular diameter of contralateral testicle was evaluated. Following a definite period of unilateral testicular torsion (i.e., 4 h), the protective effect of this specific medication was evaluated both after detorsion and orchiectomy procedures. The results of our study demonstrated the protective effect of verapamil on both parameters, especially in animals undergoing orchiectomy. The majority of the specimens demonstrated normal histologic findings together with preserved tubular structures after a 1-week period under verapamil medication.

Animals↗

PubMed1999

Semiquantitative evaluation of testicular histology after testicular torsion: protective effect of external cooling.

To evaluate the protective effect of external cooling on testicular histology and tubular diameter, an experimental study was performed on rat testes that underwent a torsion procedure for a defined period of time (4 h). In a second group of animals external cooling for 90 min was performed during the torsion procedure. Evaluation of both the semiquantitative testicular histology and tubular diameter demonstrated a relatively well-preserved histology and tubular diameter. However, significant changes were noted in testes that underwent the torsion procedure without any protective measure. Our results indicate the protective effects of hypothermia in ischemic testes undergoing torsion with regard to both histologic and tubular alterations.

Animals↗