PubMed Health⌕ Search

Biomedical subjects

H Kaya

Publications and source records attributed to H Kaya.

At least 55 records · Page 3Linked to original sources
PubMed1999

Identification of three kinds of mutually related composite elements conferring S phase-specific transcriptional activation.

Conservation of the Oct motif (CGCGGATC) is a remarkable feature of plant histone gene promoters. Many of the Oct motifs are paired with a distinct motif, Hex, TCA or CCAAT-box, constituting the type I element (CCACGTCANCGATCCGCG), type II element (TCACGCGGATC) and type III element (GATCCGCG-N14-ACCAATCA). To clarify the roles of these Oct-containing composite elements (OCEs) in cell cycle-dependent and tissue-specific expression, we performed gain-of-function experiments with transgenic tobacco cell lines and plants harboring a derivative of the 35S core promoter/beta-glucuronidase fusion gene in which three or four copies of an OCE had been placed upstream. Although their activities were slightly different, results showed that each of the three types of OCEs could confer the ability to direct S phase-specific expression on a heterologous promoter. In transgenic plants, the type I and III elements exhibited a similar activity, directing expression in meristematic tissues, whereas the activity of the type II element appeared to be restricted to young cotyledons and maturating guard cells. Mutational analyses demonstrated that the co-operation of Oct with another module (Hex, TCA or CCAAT-box) was absolutely required for both temporal and spatial regulation. Thus, OCEs play a pivotal role in regulation of the expression of plant histone genes.

Base Sequence↗
PubMed1999

Characterization of ureteral lesions associated with impacted stones.

BACKGROUND: Few studies have addressed the various types of ureteral lesions apparent in patients treated for ureteral stones, especially in those with impacted stones. Macroscopic and microscopic analyses of ureteral lesions associated with impacted stones were therefore undertaken. METHODS: From May 1994 to October 1996, 36 patients with ureteral stones, 21 of whom showed stone impaction, were treated with transurethral ureterolithotripsy. After ureteroscopic examination, biopsied specimens were obtained from six patients with impacted stones and were examined microscopically by conventional hematoxylin and eosin staining. RESULTS: Ureteroscopy revealed two types of mucosal lesions in the patients with impacted stones: Type 1 lesions were defined as edematous or cystic hemispheric lesions and occurred in 18 patients, whereas type 2 lesions had a villous appearance and were present in three patients. Microscopically, type 1 lesions appeared as submucosal edema without specific findings, whereas type 2 lesions appeared as columnar mesenchymal tissue coated with several layers of transitional epithelium. With regard to factors that might contribute to lesion formation, duration of stone presence was significantly greater for patients with impacted stones than for those with-non-impacted stones. However, no differences in such parameters were apparent between patients with type 1 lesions and those with type 2 lesions. CONCLUSIONS: Two types of ureteral lesions associated with impacted stones were confirmed microscopically. The duration of stone presence is a potential contributing factor in the development of ureteral lesions, but factors that determine the type of ureteral lesion remain unclear.

Adult↗
PubMed1999

Effect of ovarian involvement on the frequency of luteinized unruptured follicle in endometriosis.

OBJECTIVE: When we review the current literature on endometriosis and luteinized unruptured follicle (LUF), we see that most of the studies deal with only the association between LUF frequency and the severity of endometriosis. Our purpose was to evaluate the effect of ovarian involvement on LUF frequency in endometriosis and assess the relationship between endometriosis and LUF in infertile women. STUDY DESIGN: This study is a prospective analysis covering a total of 126 infertile women between 22 and 35 years of age who underwent diagnostic laparoscopy from September 1995 to August 1997 in the Department of Obstetrics and Gynecology at Süleyman Demirel University, Isparta, Turkey. Endometriosis was diagnosed in 58 of these patients. All had received a revised American Fertility Society staging score at the time of the laparoscopic diagnosis. Diagnosis of LUF was made when the following criteria were fulfilled: absence of ultrasonic signs of ovulation, and absence of an ovulation ostium on the follicle by laparoscopy, despite increased serum progesterone. Statistical evaluation was performed using chi2 test and Fisher's exact test where appropriate. RESULTS: The prevalence of LUF in mild, moderate and severe endometriosis cases was 13.3, 41.2 and 72.7%, respectively. The LUF frequencies were 45.9% in 37 endometriosis patients with ovarian involvement, 9.5% in 21 cases without ovarian involvement, and 5.9% in 68 cases without endometriosis. A statistically significant difference was observed between the LUF rate in the group with ovarian involvement and that without involvement (chi(2) = 8.06, p < 0.001). CONCLUSION: In summary, in this study we noted a significant increase in LUF frequency in endometriosis patients with ovarian involvement.

Adult↗
PubMed1999

Merits of soft nitriding scalers.

BACKGROUND: It has been demonstrated that nitriding modifies the physical characteristics of metals. The purpose of this study was to evaluate the changes induced by 3 levels of inexpensive soft nitriding treatments on commercial sickle scalers. METHODS: Taglite scalers (NT) were soft nitrided for 30 (SN30), 60 (SN60), or 90 (SN90) minutes. The cumulated scaled material was weighed every 10 strokes x 10 and thereafter every 1,000 to 8,000 strokes by an automatic scaling apparatus against epoxy resin. Weight differences were used to indicate abrasion resistance; the relative efficiency (RE) was calculated as the ratio of scaled amount at a given number of strokes (SN/NT). The hardness and the tensile strengths were determined for each soft nitriding treatment level. The nitrided layer thickness of representative SN scalers was observed by electron probe x-ray microanalysis. RESULTS: The SN60 was not significantly different from SN30 or SN90, but the SN90 was more efficient than SN30 for the first 100 strokes (P<0.01). The RE of all SN scalers was significantly greater (2.3 to 2.7 times) than the NT scalers from the beginning of the study and throughout all time periods (SN90 > SN60 > SN30); it increased further during the first 100 strokes (9.7 to 15.5 times), indicating the NT scalers wore out faster than SN scalers. The untreated scalers' performance decreased to 10% of baseline after 100 strokes; but even after 1,000 strokes, the SN60 and SN90 performed better than new untreated scalers. Thereafter, all scalers' performance, including SN scalers, decreased. While the NT blades ceased to cut measurable amounts after 7,000 to 8,000 strokes, all SN scalers continued to cut. Although SN90 scalers had the thickest soft layer and were the hardest (P<0.01), the SN60 had the highest tensile strength (P <0.01), suggesting that it might be the safest in practice. CONCLUSIONS: Sixty minutes of soft nitriding treatment of commercially available taglite scalers seem to be the optimal treatment duration to increase their durability, on the order of 100 to 1,000 times, without jeopardizing safety for clinical use.

Dental Alloys↗
PubMed1999

The effect of melatonin application on lipid peroxidation during cyclophosphamide therapy in female rats.

OBJECTIVE: Our purpose was to investigate whether melatonin has any protective effect against lipid peroxidation induced by cyclophosphamide. MATERIAL AND METHODS: We used an animal model to study the effect of melatonin. Fifteen female Wistar rats (180-200 gram in weight) were randomly assigned to three different groups. Group 1 (n = 5) received saline injections as a control. Group 2 (n = 5) received cyclophosphamide. Group 3 (n = 5) received cyclophosphamide + melatonin. The animals were sacrificed two hours after cyclophosphamide administration and blood samples were taken and used for assaying superoxide dismutase (SOD) activity, glutathione peroxidase (GP) activity for the antioxidative enzymes, and malondialdehyde (MDA) level as an index of lipid peroxidation. RESULTS: MDA levels were more increased in the second group compared with the control group (p < 0.01). In the third group, they were significantly lower than in the second group (p < 0.05). SOD and GP activities were found to be decreased significantly in the second group compared with the control group (p < 0.05 and p < 0.01, respectively). They were found to be elevated in the third group compared with the second group (p > 0.05 and p < 0.05, respectively). CONCLUSIONS: The above results suggest that melatonin has a protective role in cyclophosphamide induced lipid peroxidation in rats. Besides scavenging the highly toxic free radicals, melatonin also stimulates the antioxidant enzyme activity of GP.

Animals↗
PubMed1998

The importance of serum transferrin receptor level in the diagnosis of functional iron deficiency due to recombinant human erythropoietin treatment in haemodialysis patients.

In haemodialysis (HD) patients, functional iron deficiency frequently appears due to recombinant human erythropoietin (r-HuEPO) treatment. However, the diagnosis of iron deficiency is not always easy in such patients. Recent studies have shown that the serum transferrin receptor (s-TfR) level is a sensitive, quantitative measure of tissue iron deficiency. In this study, we examined the changes in s-TfR levels in patients with iron deficiency anaemia due to r-HuEPO treatment. We compared s-TfR levels of 24 patients with i.v. administered r-HuEPO (50-70 U/kg/dose) at the end of each dialysis session (three times a week) and diagnosed as having iron deficiency anaemia by routine laboratory methods (ferritin <50 microg/l and transferrin saturation <16%) with s-TfR levels of 32 patients not receiving r-HuEPO and without iron deficiency anaemia. Also, 40 healthy volunteer subjects were included in the study as a control group. Serum ferritin and transferrin receptor levels were measured with ELISAs using monoclonal reagents. There were no differences between the two groups with and without iron deficiency anaemia with respect to mean age, body weight, haemodialysis duration, haemoglobin and serum creatinine levels (p>0.05). For s-TfR levels, while no difference was present between the control and the non-iron deficiency groups (p>0.05), the iron deficiency group had higher s-TfR values than those of both the control and non-iron deficiency groups (p<0.001). Besides, there was an inverse correlation between haemoglobin and s-TfR levels in patients with iron deficiency anaemia (r = -0.85, p<0.0001). We conclude that the measurement of s-TfR levels may be useful in the diagnosis of functional iron deficiency in haemodialysis patients receiving r-HuEPO.

Adult↗
PubMed1998

The effect of etomidate induction on plasma cortisol levels in children undergoing cardiac surgery.

OBJECTIVE: To investigate the effect of a single induction dose of etomidate on plasma cortisol and adrenocorticotrophic hormone (ACTH) levels in pediatric patients with congenital heart disease. DESIGN: A prospective, randomized study. SETTING: A university hospital. PARTICIPANTS: Thirty children undergoing cardiopulmonary bypass. INTERVENTIONS: Patients were randomly allocated into two groups to receive etomidate, 0.3 mg/kg, and fentanyl, 1 microg/kg, or ketamine, 1 mg/kg, and fentanyl, 1 microg/kg intravenously, for anesthesia induction. Anesthesia was maintained with 50% nitrous oxide and 0.5% isoflurane in oxygen. Plasma cortisol and ACTH levels were measured on five occasions: preoperatively, after induction of anesthesia, after cross-clamping, at the end of surgery, and 24 hours postoperatively. MEASUREMENTS AND MAIN RESULTS: Plasma cortisol levels of the etomidate group decreased with anesthesia induction and remained significantly low during cardiopulmonary bypass, at the end of operation, and 24 hours postoperatively. Plasma cortisol levels of the etomidate group after the anesthesia induction, during cardiopulmonary bypass, and at the end of the operation were significantly lower than the ketamine group. CONCLUSION: These results show that etomidate is a suitable agent for suppressing the increase in cortisol levels associated with the stress response caused by cardiopulmonary bypass in children with congenital heart defects, and can be used safely.

Adrenocorticotropic Hormone↗
PubMed1997

The influence of the masticatory hypofunction on the craniofacial growth and development in rats.

In the present study, one masticatory hypofunction group and one normal function group were comprised of growing Wistar albino rats. The influence of the masticatory hypofunction on the growth and development of the craniofacial skeleton in rats was examined. The normal function group received the diet in the form of hard pellets, but the hypofunction group was fed powdered food. To avoid growth reduction because of nutritional deficiency, the animals were fed ad libitum, diet and water. At the end of the experimental period, the 90-day-old adult animals were killed and the direct anthropometric cranial, maxillary, and mandibular measurements were made on the skulls. The significant results can be summarized as follows: Total skull length, total anterior face height, lower anterior face height, ramus mandibula height, corpus mandibula height, premaxillary length, and maxillary width have been reduced but foramen incisivum width has been increased. This study showed that there is no significant effect of the masticatory hypofunction on the cranial growth and development in the growing rats, but that masticatory hypofunction affected the growth and development of the maxillofacial skeleton.

Animal Nutritional Physiological Phenomena↗
PubMed1997

Treatment of acute myeloid leukemia and myelodysplastic syndrome with orally administered cytarabine ocfosfate and granulocyte colony-stimulating factor.

Cytarabine ocfosfate (SPAC) was administered orally to 19 patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). SPAC was administered at doses of 200-300 mg/day for more than 14 days with granulocyte colony-stimulating factor (G-CSF). Four of the 12 patients with AML and 1 of the 7 patients with MDS achieved complete remission (CR) after one cycle of SPAC treatment. Especially, 3 of the 6 patients with newly diagnosed AML achieved CR. Major side effects of SPAC were myelosuppression and tolerable gastrointestinal disorders. The treatment with SPAC is a therapeutic option in elderly patients or patients with organ failure.

Administration, Oral↗
PubMed1997

Vulvar dystrophy: an evaluation of 285 cases.

To determine the effectiveness of medical therapy in vulvar dystrophy, a retrospective, single-institute clinicopathologic study of 285 consecutive cases was carried out. Of the patients, 152 (53.3%) had squamous hyperplasia (SH), 72 (25.3%) had lichen sclerosus (LS), and 61 (21.4%) had lichen sclerosus with areas of squamous hyperplasia (LS + SH). Symptomatic response was 84.8% at 3 months and 92.7% at 6 months in patients with SH. These figures were 70.8% and 87.5% for patients with LS and 68.8% and 80.3% for patients with SH + LS, respectively. Histopathological response was 63.6% at 3 months and 74.8% at 6 months for patients with SH. These figures were approximately 29% and 42% for LS, and 21% and 34% for patients with SH + LS, respectively. Corticosteroids for squamous hyperplasia and testosterone for lichen sclerosus achieved a high symptomatic response. However, histologic remission rates were poorer.

Adult↗
PubMed1996

A new needle suspension procedure for genuine stress incontinence and anterior vaginal wall prolapse.

A new suspension method was developed for the correction of anterior vaginal wall relaxation and genuine stress incontinence. This procedure suspends the anterior vaginal wall to the anterior rectus fascia, and in doing so gives support to the bladder neck, anterior vaginal wall and vaginal apex. The procedure is performed at the time of vaginal hysterectomy or correction of anterior vaginal wall relaxation. The authors present their experience with this technique in 31 patients.

Fasciotomy↗
PubMed1996

[Low-dose combination cytarabine and etoposide for myeloid crisis transformed from unclassified chronic myeloproliferative disorder].

A 65-year-old man visited our department for further leukocytosis examination. Hematological examinations disclosed elevation of the leukocyte count with left deviation. The neutrophilic alkaline phosphatase score was reduced. Bone marrow was hypercellular and consisted almost entirely of granulocytic cells in all stages of maturation. However, cytogenetic analysis revealed no Philadelphia chromosome, and genotypic analysis disclosed no bcr rearrangement. He was ultimately diagnosed as having unclassified chronic myeloproliferative disorder. He had been followed without chemotherapy, and he developed blastic crises (CD10+, CD13+, CD24+). Chemotherapy was effective, and then he was followed with carboquone. However, myeloid crisis (CD13+, CD33+) developed again. Standard chemotherapies had no effect, he developed pneumonia, and he was in poor general condition. Therefore, low-dose combination with cytarabine and etoposide was performed. The result was that the blasts disappeared, his general condition improved and infection was reduced. Major side effects were absent; however, the blasts proliferated again after the treatment was discontinued. In conclusion, this combination may be useful treatment for myeloid blastic crises even if the patient is in poor condition. But the modification of the administration schedule requires some consideration.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

[Multidrug resistant P-glycoprotein expression on acute nonlymphocytic leukemia cells at diagnosis].

In performing cancer chemotherapy, it is essential to know the expression of multidrug resistant (MDR) P glycoprotein (p-gp) on cancer cells. In the present study, in order to clarify the relationship between MDR of leukemic cells and cytologic, immunological and clinical features of acute nonlymphocytic leukemia (ANLL), leukemic cells in peripheral blood and/or bone marrows obtained from 28 ANLL patients were examined. Each smear was stained with C219 monoclonal antibody against P-gp by the APAAP method, and then 1,000 ANLL cells in each smear were observed. Among the FAB subtypes, M4 showed the highest proportion of leukemic cells expressing P-gp. Concerning the response to chemotherapy, five of seven patients (71%) having 1.0% or more of P-gp positive leukemic cells and 11 of 19 patients (58%) having less than 1.0% of those cells achieved complete remission. However, there was no significant correlation between P-gp expression and clinical outcome. There was also no significant correlation between P-gp expression and CD7 or CD34. Furthermore, no significant correlation between chromosome 7 abnormality and P-gp expression was observed. From these results, if we can clarify the mechanism of MDR and the relationship between MDR and cytogenetic or clinical features of ANLL with further study, P-gp expression may become a useful marker for predicting the outcome of ANLL.

ATP Binding Cassette Transporter, Subfamily B, Mem↗