Biomedical subjects

A Eroglu

Publications and source records attributed to A Eroglu.

30 records · Page 2Linked to original sources

PubMed2000

Intracellular trehalose improves the survival of cryopreserved mammalian cells.

We report that the introduction of low concentrations of intracellular trehalose can greatly improve the survival of mammalian cells during cryopreservation. Using a genetically engineered mutant of Staphylococcus aureus alpha-hemolysin to create pores in the cellular membrane, we were able to load trehalose into cells. Low concentrations (0.2 M) of trehalose permitted long-term post-thaw survival of more than 80% of 3T3 fibroblasts and 70% of human keratinocytes. These results indicate that simplified and widely applicable freezing protocols may be possible using sugars as intracellular cryoprotective additives.

3T3 Cells↗

PubMed2000

Isolated limb perfusion with cisplatin and doxorubicin for locally advanced soft tissue sarcoma of an extremity.

AIMS: To identify independent adverse clinico-pathological factors for disease-free and overall survival in patients undergoing isolated limb perfusion (ILP) with cisplatin and doxorubicin for locally advanced soft tissue sarcoma (STS) of an extremity. METHODS: A retrospective analysis was carried out, using a univariate method and a multivariate analysis, to look at the patient, tumour and treatment associated with prognostic factors in 37 patients with locally advanced STSs of the limbs who underwent ILP with cisplatin and doxorubicin. Patient's age, gender, presenting status, tumour location, tumour grade, tumour stage according to TNM classification, tumour size and radiotherapy (RT) were analysed. Survival curves were calculated according to the Kaplan-Meier method. A Cox proportional hazard model was used to indicate which factors related to overall survival and the recurrence-free interval after ILP. RESULTS: No major systemic toxicity was seen. Regional toxicity was limited. Limb salvage was achieved in 94.6% of the patients. The estimated 5-year overall and disease-free survival rates were 62% and 54%, respectively. It was found that tumour stage, tumour grade, presenting status, RT and tumour size were associated with cumulative overall survival when the Kaplan-Meier method was applied (P<0.05). By Cox proportional hazards model, only tumour grade (P=0. 0254) was found to have significant influence on overall survival; however, tumour stage (P=0.0157) and RT (P=0.0014) were related to disease-free survival. CONCLUSIONS: ILP and delayed excision followed by RT achieves good limb salvage rates and may improve survival.

Adult↗

PubMed1998

Cytoskeleton and polyploidy after maturation and fertilization of cryopreserved germinal vesicle-stage mouse oocytes.

PURPOSE: Our purpose was to assess the effect of cryopreservation on cytoskeleton of germinal vesicle (GV) mouse oocytes and determine whether irreversible spindle damage and related digyny associated with cryopreservation of metaphase II (MII) oocytes can be avoided. METHODS: The GV oocytes were cryopreserved using a slow-cooling (0.5 degree C/min) and slow-thawing (8 degrees C/min) protocol in 1.5 M dimethylsulfoxide supplemented with 0.2 M sucrose and analyzed before and during fertilization by multiple-label fluorescence and differential interference contrast microscopy techniques. RESULTS: When examined after in vitro maturation, the vast majority (> 95%) of cryopreserved and control oocytes displayed normal microfilament and microtubule organization. With respect to barrel-shaped spindle and normal chromosome alignment, no significant differences were observed between cryopreservation (78 and 86%, respectively) and control (85 and 95%, respectively) groups. In fertilization experiments, spindle rotation, formation of the second polar body, and pronuclear migration were displayed by similar percentages of cryopreserved (96, 94, and 37%, respectively) and control (98, 97, and 45%, respectively) oocytes, indicating normal functionality of the cytoskeleton during this period. However, pronuclear formation was significantly inhibited by cryopreservation (81%) compared with controls (100%). Regarding digyny and polyspermy, no significant increase was observed after cryopreservation (3 and 10%, respectively) compared with controls (3 and 6%, respectively). CONCLUSIONS: Cryopreservation of mouse oocytes at the GV stage is particularly advantageous to circumvent the spindle damage and increased digyny noted after cryopreservation of MII oocytes.

Actin Cytoskeleton↗

PubMed1998

Alterations of the cytoskeleton and polyploidy induced by cryopreservation of metaphase II mouse oocytes.

OBJECTIVE: To determine cryopreservation-induced alterations in the cytoskeleton of metaphase II mouse oocytes and the implications of these alterations in functionality of the cytoskeleton and polyploidy after fertilization. DESIGN: Comparative study. SETTING: Clinical and academic research environment at a medical school teaching hospital. INTERVENTION(S): Oocytes were frozen using a slow-cooling (0.5 degrees C/min) and slow-thawing (8 degrees C/min) protocol in 1.5 M dimethyl sulfoxide and 0.2 M sucrose and were analyzed before and after fertilization. MAIN OUTCOME MEASURE(S): Cytoskeletal alterations, fertilization, and polyploidy rates. RESULT(S): When analyzed immediately after thawing, the oocytes displayed dramatic cytoskeletal alterations. Only slight recovery was observed upon removal of the cryoprotectants. However, incubation after thawing of 1 hour at 37 degrees C completely reestablished a normal microfilament and microtubule pattern while partially restoring normal spindle morphology and chromosome alignment. Accordingly, insemination immediately after removal of cryoprotectants resulted in a significantly decreased fertilization rate and aberrant dynamics of cytoskeleton-dependent events, whereas oocytes inseminated after the post-thaw incubation displayed fertilization rates and cytoskeletal dynamics comparable to those in controls. Cryopreservation did not increase polyspermy but significantly increased digyny when the oocytes were inseminated after the post-thaw incubation. All digynic eggs displayed an abnormal spindle remnant in comparison with diploid or polyspermic eggs. CONCLUSION(S): A brief period of incubation after thawing allows recovery and positively affects fertilization and cytoskeletal dynamics. Cryopreservation does not impair the functionality of microfilaments and cytoplasmic microtubules during postfertilization events. Our findings suggest that the increased rate of digyny in cryopreserved oocytes may be related to the spindle disorganization, leading to failure in segregation of the chromosomes, rather than to direct malfunction of the microfilaments in polar body formation.

Animals↗

PubMed1997

Anomalous origin of circumflex coronary artery from the right pulmonary artery associated with subaortic stenosis and coarctation of the aorta.

Anomalous origin of the circumflex coronary artery is extremely rare and may cause acute cardiac decompensation associated with correction of coexisting congenital malformations. We describe a 10-year-old female patient who underwent surgical repair of the aortic coarctation at 4 years of age. Six years later, she presented with chest pain during exercise. Cardiac catheterization demonstrated 25 mmHg subaortic systolic gradient and retrograde filling of the circumflex coronary artery from the left anterior descending and right coronary artery, with drainage into the right pulmonary artery. Reimplantation of the anomalous circumflex coronary artery to the aorta and resection of subaortic fibrous membrane was performed. Her postoperative course was uneventful, with complete relief of symptoms.

Aortic Coarctation↗

PubMed1996

Fertilization and development of mouse oocytes cryopreserved using a theoretically optimized protocol.

Rational design of a cryopreservation protocol was demonstrated by using theoretical models of the cryopreservation process to develop an optimal freezing protocol for mouse oocytes. A coupled mechanistic model of the processes of freeze-induced cell dehydration and intracellular ice formation was developed, and cryomicroscopical measurements of intracellular ice formation kinetics were used to determine biophysical parameters required by the model, and to test model predictions of the freezing behaviour of mouse oocytes. A simple phenomenological model for oocyte damage resulting from exposure to concentrated electrolyte and cryoprotectant solutions during cryopreservation was obtained by defining a cost function equal to the duration of the freezing protocol. A two-step freezing protocol was theoretically optimized by using a sequential simplex algorithm to minimize the cost function, subject to the constraint that the predicted probability of intracellular ice formation remain below 5%, yielding a putative optimum at the cooling rate B = 0.59 degrees C/min, and plunge temperature Tp = -67 degrees C. By systematically varying B and Tp about these values in experiments with mouse oocytes cryopreserved in 1.5 M dimethyl sulphoxide, the maximal recovery of intact oocytes with a normal morphology (82%) was obtained for B = 0.5 degrees C/min and Tp = -80 degrees C. Further evaluation of the fertilizability and developmental capacity of oocytes cryopreserved using the optimized protocol yielded cleavage to the 2-cell stage in 65% of oocytes inseminated, and blastocyst formation in 50% of these 2-cell embryos.

Animals↗

PubMed1994

[The effect of the covering of mares during the postpartum heat on the pregnancy rate].

The present study was carried out to investigate the pregnancy rate after covering in the foal heat (Group I), in the subsequent spontaneous heat (Group II), and in the induced heat (Group III) after administration of 7.5 mg of the prostaglandin F2 alpha analogue Luprostiol (Reprodin, Bayer) between the 20th and 22nd day post partum. Breeding during foal heat resulted in a pregnancy rate of 43.9% compared to 48.6% in the subsequent spontaneous heat post partum. Of 18 mares in group III, 14 mares had a foal heat, whereas 4 others had not shown a foal heat. 1-8 days after treatment, 14 mares (77.8%) returned to an oestrus. In consideration of the mares which had shown a foal heat, oestrus was induced in 85.7% of treated mares. In this group, a pregnancy rate of 50.0% was achieved. In conclusion, the results of the present study indicate that induction of oestrus by treatment with prostaglandin 20-22 days after parturition for covering is a good alternative.

Animals↗

PubMed1993

Experimental studies on in vitro maturation of porcine oocytes. I. Effects of medium, energy source and protein source on in vitro maturation rate.

Effects of culture medium, energy and protein source on in vitro maturation of cumulus-intact porcine oocytes were examined. The bicarbonate buffered Whittens medium was superior to the PB1 medium buffered with phosphate salts in supporting in vitro maturation. However, modification of energy source of the PB1 medium by reducing Na-pyruvate concentration and adding lactate salts gave also high maturation rate. The supplementation of Whittens medium with 1 g and 3 g BSA/l as a protein source significantly increased incidence of maturation and improved handling of oocytes. There was no significant difference in the ability of low concentration (1 g/l) and high concentration (3 g/l) of BSA in culture medium to support maturation.

Animals↗

PubMed1993

Experimental studies on in vitro maturation of porcine oocytes. II. Effects of estradiol-17 beta and progesterone.

The simple compounded semi-defined Whitten's medium was supplemented with estradiol-17 beta and progesterone to examine whether they influence the nuclear maturation of porcine cumulus-oocyte complexes. Addition of estradiol-17 beta at concentrations of 1.0 microgram/ml and 10.0 micrograms/ml significantly inhibited the nuclear maturation in comparison to the control group. No significant inhibition of estradiol-17 beta was observed at concentration of 0.1 microgram/ml with respect to the control. After addition of synchronous or subsequent (12 h after the incubation with estradiol-17 beta) supplementation of progesterone at concentration of 1 microgram/ml, maturation rates were as high as control. So progesterone overcame the inhibitory effect of estradiol-17 beta.

Animals↗

PubMedDate not supplied

Retroperitoneal soft tissue sarcoma: effect of hyperthermic total abdominal perfusion.

AIMS AND BACKGROUND: Soft tissue sarcomas (STS) of the retroperitoneum are rare tumors. Surgery remains the principal modality of therapy in the management of primary and recurrent retroperitoneal STS. However, little is known about the effect of regional chemotherapy using hyperthermic total abdominal perfusion (HTAP). We analyzed independent prognostic variables in 33 patients with STS in the retroperitoneum admitted from November 1990 through December 1996. METHODS AND STUDY DESIGN: Data regarding patients' age, gender, tumor size, histological tumor type, tumor location, type of operation (primary or secondary surgery), extent of surgical management (marginal or extended), use of HTAP, tumor grade, and tumor stage according to the TNM classification were examined by univariate and multivariate analyses. RESULTS: All 33 patients underwent complete resections (marginal or extended). Eleven of them received locoregional chemotherapy by HTAP. The overall cumulative 5-year survival rates in patients with stage IIA and advanced disease were 82% and 22%, respectively (log-rank test, P<0.01). Using Cox's proportional hazard model, tumor stage, use of HTAP and type of operation were found to have significant influence on overall survival (P<0.05). CONCLUSIONS: Our results showed that complete resection along with HTAP chemotherapy may improve survival in patients with retroperitoneal STS. These phase II data could be used to support the initiation of a phase III trial to test HTAP in patients submitted to complete resection of retroperitoneal STS.

Adult↗

PubMedDate not supplied

Correlation between tissue levels of carboxy-terminal propeptide of type I procollagen and clinicopathological characteristics in human colorectal cancer.

BACKGROUND/AIMS: Type 1 collagen is the most abundant protein in the human body and a major constituent of the interstitial connective tissue. However, little is known about carboxy-terminal propeptide of type I procollagen (PICP) expression in human colorectal tumor tissues. We therefore evaluated the concentrations of PICP in colorectal tumor tissue as well as surrounding normal tissues and examined the relationship between its level and clinicopathological variables. METHODOLOGY: Tumor and normal tissues from 40 patients with colorectal carcinoma who had been operated on were stored at -80 degrees C until assays. PICP was assayed by sandwich immunoassay. RESULTS: It was found that the PICP level was significantly higher in the tumor extracts than in the normal tissue extracts (P < 0.0001). The ANOVA test showed that the level of PICP in tumor tissue was higher in the patients with advanced colorectal tumor than those with early stage disease (P < 0.0001). There were statistically significant differences with regard to the depth of tumor invasion, presence of lymph node metastasis, and hepatic metastasis (P < 0.05). There were also quantitative differences with respect to the PICP levels between obstructing tumors and non-obstructing carcinoma (P < 0.05), but the elevated PICP levels in tumor tissues were not associated with the type of histologic differentiation (P > 0.05). CONCLUSIONS: Although these findings suggest that PICP value in tumor tissue is most likely related to the some histomorphological architecture of the tumor, the authors believe that the prognostic significance of PICP expression in primary colorectal tumor and normal tissues requires further evaluation.

Adult↗

PubMedDate not supplied

Survival after curative resection for stage IE and IIE primary gastric lymphoma.

BACKGROUND/AIMS: There is considerable controversy regarding the optimal treatment of patients with primary gastric lymphomas. However, surgery still plays an important role in the management of stage IE and IIE gastric lymphomas. We aimed at assessing survival of primary gastric lymphoma cases with stage IE or IIE that were surgically treated at the Surgical Oncology Department. METHODOLOGY: Thirty-seven patients with stage IE and IIE primary gastric lymphoma who were surgically treated and had complete follow-up from January 1990 to September 1998 were reviewed retrospectively. Patients' age, gender, tumor location, tumor grade, histologic type, depth of tumor invasion, regional lymph node status, tumor stage, type of gastrectomy (total/subtotal), combined resection, extensive lymphadenectomy, adjuvant chemotherapy were used as the clinicopathologic variables. RESULTS: Five-year survival rates for stage IE and stage IIE disease were 75% and 37%, respectively. The overall 5-year survival rate of the patients was 57%. Univariate analysis demonstrated that age, tumor stage, and type of gastrectomy were associated with prognosis, but only type of gastrectomy (subtotal gastrectomy) and tumor stage were found to be independent prognostic factors (P < 0.05). CONCLUSIONS: To obtain prolonged survival we recommend radical resection with extensive lymphadenectomy for malignant lymphoma stages IE and IIE. Patients with small distal lymphomas of the stomach can be treated with subtotal gastric resection.

Adult↗