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Biomedical subjects

E Yildirim

Publications and source records attributed to E Yildirim.

At least 19 recordsLinked to original sources
PubMed2003

The prognostic significance of total lymph node number in patients with axillary lymph node-negative breast cancer.

AIM: In node-negative breast cancer patients, several factors for survival have been evaluated and currently, some of them are accepted for their prognostic and/or predictive values after validation in the separate data sets. The prognostic significance of increases in the number of pathologically detectable axillary lymph nodes in the node-negative patients could not been established clearly. To address this question, we have reviewed our patients' records. METHODS: A retrospective cohort study was conducted in pathologically node-negative patients who underwent modified radical mastectomy for stage I and II breast cancer. Survival and multivariate prognostic factor analyses were carried out to determine whether the number of tumour-free lymph nodes in complete axillary dissection material in addition to known factors was significant for the outcomes. RESULTS: Two hundred and seventy consecutive patients were eligible to enter the trial. The median observation time and the median number of tumour-free lymph nodes were 61 (from 30 to 120) months and 18 (from 10 to 44), respectively. The cohort was divided into the groups according to the number of nodes. The 5-year event-free and overall survivals were 92.5 and 98.3% for patients who had 18 lymph nodes or less, and 70 and 86.7% for those who had more than 18 negative nodes, respectively (P < 0.00001). Multivariate analysis for event-free survival demonstrated that the number of lymph nodes (Relative risk: 3.2 and 95% confidence interval: 1.7 to 5.9) in addition to the pathological tumour size and age was the most important independent prognosticator. In similar, multivariate analysis for overall survival showed that the number of lymph nodes together with the tumour size was the significant indicator (RR of cancer-specific dying in patients who had more than 18 nodes: 3.1 and 95% CI: 1.2 to 8.5). CONCLUSION: The increases in number of tumour-free lymph nodes are clinically important and this parameter should be taken into consideration in the breast cancer patients without metastatic lymph nodes.

Adult↗
PubMed2003

Is invasive lobular carcinoma different from invasive ductal carcinoma?

AIMS: The purpose of this study is to determine whether the histopathologic features and outcome in invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC) are different, and whether the histologic type is a prognostic factor for outcome. METHODS: A retrospective cohort study was conducted in consecutive 510 stage I/II breast carcinoma patients who underwent modified radical mastectomy. The features of 65 patients with ILC were compared with those of 445 patients with IDC. In patients with median follow-up period of 44 months, univariate and multivariate prognostic factor analyses for cancer-specific death and relapse were carried out. RESULTS: The median ages in patients with ILC and those with IDC were 52 and 41 (P=0.04). Tumor size, estrogen receptor positive expression and nodal positivity were not significantly different between the histologic types. Patients with ILC had more frequently (81.5%) low grade tumors and less lymphatic vascular invasion (9.3%) in primary tumor than those with IDC (P<0.05). Whereas the rates of 5-year overall survival were 94% in ILC and 90% in IDC, the rates of 5-year event-free survival were 71 and 67%, respectively (P=NS). Multivariate analyses in all patients demonstrated that tumor size, pathologic lymph node status and age at diagnosis were the most important prognostic factors for overall and event-free survival. Histologic type was not statistically significant for both outcomes. CONCLUSIONS: Although patients with ILC had older age, low grade tumor and less lymphatic vascular invasion, they had no survival advantage comparing with their counterparts. Histologic type was not an independent prognostic factor for outcome.

Adult↗
PubMed2003

The importance of the time interval between diagnosis and operation in myasthenia gravis patients.

AIM: Complete remission rates in patients with myasthenia gravis (MG) using anticholine esterases, immunosuppressive drugs, and medical therapy methods like plasmapheresis are low. Because high levels of complete remission and advantages are reported after thymectomy this surgical method is widely used in patients with MG. METHODS: The preoperative status and the responses to thymectomy have been studied in 15 patients who had been diagnosed as MG and underwent thymectomy in Ankara Numune Education and Research Hospital. RESULTS: Patients who underwent thymectomy have shown a high proportion of clinical improvement (73%). We could not establish a direct relationship between the results and the patients' age, sex features and the pathological characteristics of the excisional biopsy specimens. The benefit rates for patients who had a short period of time between diagnosis and operation (87.5%) were higher (91%). CONCLUSIONS: Thymectomy because of its high benefit rate is an advantageous therapeutic tool. The chance of benefiting from thymectomy increases when the history of MG is short and the stage of the disease is early.

Adolescent↗
PubMed2002

The effects of fusidic acid on the inflammatory response in rats.

In the present study the antiinflammatory activity of fusidic acid was investigated in a model of formalin-induced edema formation in rats. Fusidic acid at doses of 50 and 100 mg kg (-1) was administered p.o. to rats for ten days. It was observed that fusidic acid inhibited edema formation significantly (P< 0.05). After this period, gastric mucus secretions were evaluated by the Alcian blue dye binding method. Mucus secretion decreased significantly in the control group. Fusidic acid increased the amount of gastric mucus. Moreover, in all of the animals with paw edema, platelet count was also increased. Red blood cell count, haemoglobin concentration and haematocrit were all higher in the control group than those of the fusidic acid groups. The present observations suggest that fusidic acid suppressed the inflammatory response and stimulated the gastric mucus secretion and it prompts further experiments for delineation of the mechanism of these actions as well as clinical trials.

Animals↗
PubMed2001

Synthesis and antinociceptive activity of (2-benzazolon-3-yl)propionamide derivatives.

The syntheses of (2-benzothiazolinon-3-yl)propionamide and (2-benzoxazolinon-3-yl)propionamide derivatives are reported. The structures of these compounds are elucidated by their IR and 1H-NMR spectral data, as well as by elemental analysis. The compounds were tested for antinociceptive activity by hot plate, tail flick, tail clip, and modified Koster tests. Compounds 6b and 7d were found to be the most promising compounds among the substances investigated.

Amides↗
PubMed2001

The Turkish experience with curative gastrectomies for gastric carcinoma: is D2 dissection worthwhile?

BACKGROUND: The only possible curative treatment in gastric carcinoma is surgery, and there is still controversy surrounding the value of extended lymph node dissection. STUDY DESIGN: A retrospective cohort study was conducted in patients who underwent curative D1 or D2 resection for operable gastric carcinoma. Survival and multivariate prognostic factor analyses were carried out to determine whether dissection type was significant for outcomes, and which subgroup of patients would benefit from D2 dissection. RESULTS: Three hundred one patients who had potentially curative treatment were eligible to enter the trial. Although mortality rates were 3.1% in the D1 group and 4.3% in the D2 group (p = NS), morbidity rates in the D1 and D2 groups were 6.2% and 27.9%, respectively (p<0.05). Multivariate analysis showed that lymph node dissection type, Borrmann type of tumor, number of metastatic lymph nodes, and depth of wall invasion were the most important independent prognosticators. Five-year disease-free and overall survival rates were 19% and 36% in D1, and 49% and 54% in D2, respectively (p<0.05). After stratifying for pT and pN, the significant survival advantage with D2 was observed in subgroups of pT2, pT3 and pN1, pN2. The subset analysis showed a significant prognostic benefit with D2 dissection in patients in stages II and III-A. CONCLUSIONS: D2 dissections can be carried out with low mortality rates, but they have high morbidity rates and a survival advantage over D1 dissection of only 18%. In principle, a survival benefit with D2 is obtained especially when the tumor invades muscularis propria, penetrates serosa without invasion of adjacent structures, or metastasizes to fewer than fifteen regional lymph nodes. Data in this homogeneous population support the use of extended lymphadenectomy for selected group of patients with gastric carcinoma.

Adenocarcinoma↗
PubMed2001

Morning-evening administration time differences in digoxin kinetics in healthy young subjects.

Digoxin, frequently used in the treatment of congestive heart failure, has a very narrow therapeutic index. We studied the differences in digoxin pharmacokinetics when ingested in the morning versus evening. A single digoxin (0.25 mg) dose was given orally to the same group of 10 diurnally active healthy (6 male and 4 female) volunteers in the morning at 08:00 and evening at 20:00 in separate experiments scheduled 2 weeks apart. Blood samples were collected at specific times for 48h after each timed dose; digoxin was determined by radioimmunoassay (RIA). Maximum plasma concentration Cmax; Tmax, the time to reach Cmax; area under plasma concentration curve AUC; and elimination half-time T1/2 of digoxin were determined. Tmax was statistically significantly shorter (54 min) following 08:00 dosing com pared to 20:00 dosing (96 min). Although the Cmax was higher after morning than evening dosing, it was not significantly so. No other parameter of digoxin pharmacokinetics except Tmax exhibited administration time dependency.

Adult↗
PubMed2001

Joining of short DNA oligonucleotides with base pair mismatches by T4 DNA ligase.

Oligonucleotide-directed mutagenesis is a widely used method for studying enzymes and improving their properties. The number of mutants that can be obtained with this method is limited by the number of synthetic 25-30mer oligonucleotides containing the mutation mismatch, becoming impracticably large with increasing size of a mutant library. To make this approach more practical, shorter mismatching oligonucleotides (7-12mer) might be employed. However, the introduction of these oligonucleotides in dsDNA poses the problem of sealing a DNA nick containing 5'-terminal base pair mismatches. In the present work we studied the ability of T4 DNA ligase to catalyze this reaction. It was found that T4 DNA ligase effectively joins short oligonucleotides, yielding dsDNA containing up to five adjacent mismatches. The end-joining rate of mismatching oligonucleotides is limited by the formation of the phosphodiester bond, decreasing with an increase in the number of mismatching base pairs at the 5'-end of the oligonucleotide substrate. However, in the case of a 3 bp mismatch, the rate is higher than that obtained with a 2 bp mismatch. Increasing the matching length with the number of mismatching base pairs fixed, or moving the mismatching motif downstream with respect to the joining site increases the rate of ligation. The ligation rate increases with the molar ratio [oligonucleotide:dsDNA]; however, at high excess of the oligonucleotide, inhibition of joining was observed. In conclusion, 9mer oligonucleotides containing a 3 bp mismatch are found optimal substrates to introduce mutations in dsDNA, opening perspectives for the application of T4 DNA ligase in mutagenesis protocols.

Bacteriophages↗
PubMed2000

Deadly weapon-related open-globe injuries: outcome assessment by the ocular trauma classification system.

PURPOSE: To describe mechanisms and injury characteristics influencing visual outcomes in eyes with open-globe injuries caused by deadly weapons and to apply the classification system introduced by the Ocular Trauma Classification Group. METHODS: Two-hundred-twenty-eight eyes of 212 consecutive patients, who were mostly injured in military confrontation, were analyzed. Mechanism and injury characteristics were evaluated for predicting visual outcome according to the recently studied classification system as well as other variables pertinent to this specific clinical setting of severe eye trauma. Final visual acuities were defined as favorable (5/200 or better) or unfavorable (less than 5/200, including enucleation). RESULTS: The mean age of patients was 23 years, and the mean follow-up was 5.7 months. The predictors for favorable visual outcome were type B, grade 1, zone I, and relative afferent pupillary defect-negative injuries. The predictors for unfavorable outcome were type A, grade 5, zone III, and relative afferent pupillary defect-positive injuries. Land mine and hand grenade injuries had the worst outcome among causative agents. Proliferative vitreoretinopathy, comprising 30.4% of postoperative failures, was the most common complication. CONCLUSION: Deadly weapon-related open-globe injuries, especially those associated with land mines and hand grenades, have devastating visual results. Evaluation of trauma mechanism and injury characteristics according to the Ocular Trauma Classification System seems to predict visual outcomes in this series of severe open-globe injuries.

Adult↗
PubMed2000

The analysis of prognostic factors in stage III-B non-inflammatory breast cancer.

AIMS: To evaluate factors predicting disease recurrence in patients treated for stage III-B breast cancer by neoadjuvant chemotherapy followed by surgery. METHODS: A retrospective study of 52 patients who responded to neoadjuvant chemotherapy followed by modified radical mastectomy was carried out. The parameters studied included pre-treatment tumour size, clinical axillary status, grade, lymphatic-vascular invasion, pathological axillary status, number of metastatic lymph nodes, menopausal status and oestrogen receptor status. RESULTS: In the univariate analysis, number of metastatic lymph nodes, primary tumour size, pathological axillary status and histological grade were statistically significant factors associated with recurrence of disease. Multivariate analysis demonstrated that the number of metastatic lymph nodes (relative hazard 6.1) and primary tumour size (related hazard 2.5) were the most important independent prognostic factors for recurrence. CONCLUSIONS: These results indicate that the number of involved lymph nodes after neoadjuvant chemotherapy, independent of the clinical response of primary tumour, had a most significant impact on disease free survival. Additionally primary tumour size had a marked prognostic significance in spite of clinical changes in tumours following chemotherapy.

Adult↗
PubMed2000

Prognostic significance of young age in breast cancer.

BACKGROUND: Breast carcinoma is relatively uncommon in younger women and whether or not young age at diagnosis is an adverse prognostic factor in this disease has been controversial. Our aim in this report is to determine whether the histopathologic features and outcome in young and old are different, and whether age is a prognostic factor for relapse. METHODS: A retrospective study of consecutive 281 stage I or II breast carcinoma patients who had modified radical mastectomy was carried out. The patients with a median follow-up period of 45 months were divided two groups according to their ages. The histopathological features and survival of Group 1 and Group 2 were compared with each other. Univariate and multivariate prognostic factor analysis for relapse were carried out. RESULTS: The patients in Group 1 (younger than 35 years of age) had the worst histopathological features related to the prognosis than those in Group 2 and the difference between the two groups was statistically significant. Whereas the rates of 5-year overall survival were 65% in Group 1 and 98% in Group 2 (P < 0.05), the rates of 5-year relapse-free survival were 40% and 80%, respectively (P < 0.05). In univariate analysis of all patients, pathologic tumour size, pathologic axillary status, number of metastatic lymph nodes, pathologic stage, age, lymphatic vascular invasion were statistically significant factors associated with relapse. Multivariate analysis demonstrated that number of metastatic nodes (risk ratio RR:4.3 in more than three nodes) and age (RR:3.6 in Group 1) were the most important independent prognostic factors for relapse. In the patients without axillary involvement, both of univariate and multivariate analysis revealed that pathologic tumour size (RR:5.1 in pT(2)) and age (RR:4 in Group 1) were the independent prognosticators for relapse. CONCLUSIONS: Young patients with breast cancer had the worst histopathological features and the worst survival than their older counterparts. Age was an independent significant prognostic factor for relapse.

Adult↗
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

Synthesis and X-ray crystal structure of the calcium channel antagonist: dimethyl 1,4-dihydro-2,6-dimethyl-4-[4'-(4H-4-oxo-1-benzopyran-2-yl)phenyl]- 3,5-pyridine dicarboxylate.

The synthesis of the title compound via the Hantzsch method from 4'-flavone carboxaldehyde is described, and its molecular structure was determined by X-ray crystallography. The 1,4-dihydropyridine (1,4-DHP) ring adopts a boat conformation. The phenyl ring of the flavone is not exactly perpendicular to the DHP ring. Calcium antagonistic activity of this compound was evaluated in vitro by using BaCl2-stimulated rat ileum.

Animals↗
PubMed1999

A comparative study of recurrent pterygium surgery: limbal conjunctival autograft transplantation versus mitomycin C with conjunctival flap.

OBJECTIVE: To compare the recurrence rate following treatment of recurrent pterygia using one of two techniques-limbal conjunctival autograft transplantation versus low-dose intraoperative mitomycin C (0.2 mg/ml) combined with conjunctival flap closure. DESIGN: Randomized clinical trial. PARTICIPANTS: Eighty-one patients with recurrent pterygia treated by limbal conjunctival autograft transplantation (n= 41) or mitomycin C combined with conjunctival flap (n= 40) participated. INTERVENTION: Limbal conjunctival autograft transplantation or low-dose intraoperative mitomycin C application with conjunctival flap technique was performed on recurrent pterygium cases. MAIN OUTCOME MEASURES: Recurrence of pterygium and postoperative complications. RESULTS: During mean follow-up periods of 16+/-1.9 and 15.5+/-1.5 months, six recurrences (14.6%) in the limbal conjunctival autograft transplantation group and five recurrences (12.5%) in the mitomycin C group were observed (P=0.77). The difference between the mean ages of recurrent (26.4+/-8.0 years) and nonrecurrent (35.8+/-11.9 years) cases for all patients was statistically significant (P=0.014). Technically, limbal conjunctival autograft transplantation seemed to be more difficult. The most frequent complication in limbal conjunctival autograft transplantation was graft edema, whereas that in the mitomycin C group was superficial keratitis. CONCLUSION: Both techniques showed similar recurrence rates in the treatment of recurrent pterygia. Although technically easier to perform, further follow-up is necessary to determine the long-term safety of low-dose intraoperative mitomycin C with conjunctival flap closure. The surgeon's familiarity with either procedure should determine the method of choice.

Adult↗